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
46 | [COMMAND] | SHELL_COMMAND
47 | -d DELIM COMMAND DELIM SHELL_COMMAND
48 pipe [COMMAND] | SHELL_COMMAND
49 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
50 Executes COMMAND and sends its output to SHELL_COMMAND.
51 With no COMMAND, repeat the last executed command
52 and send its output to SHELL_COMMAND.
54 with SETTING [VALUE] [-- COMMAND]
55 w SETTING [VALUE] [-- COMMAND]
56 Temporarily set SETTING, run COMMAND, and restore SETTING.
57 Usage: with SETTING -- COMMAND
58 With no COMMAND, repeats the last executed command.
59 SETTING is any GDB setting you can change with the "set"
60 subcommands. For example, 'with language c -- print someobj'
61 temporarily switches to the C language in order to print someobj.
62 Settings can be combined: 'w lang c -- w print elements unlimited --
63 usercmd' switches to the C language and runs usercmd with no limit
64 of array elements to print.
66 maint with SETTING [VALUE] [-- COMMAND]
67 Like "with", but works with "maintenance set" settings.
69 set may-call-functions [on|off]
70 show may-call-functions
71 This controls whether GDB will attempt to call functions in
72 the program, such as with expressions in the print command. It
73 defaults to on. Calling functions in the program being debugged
74 can have undesired side effects. It is now possible to forbid
75 such function calls. If function calls are forbidden, GDB will throw
76 an error when a command (such as print expression) calls a function
79 set print finish [on|off]
81 This controls whether the `finish' command will display the value
82 that is returned by the current function. When `off', the value is
83 still entered into the value history, but it is not printed. The
88 Allows deeply nested structures to be simplified when printing by
89 replacing deeply nested parts (beyond the max-depth) with ellipses.
90 The default max-depth is 20, but this can be set to unlimited to get
91 the old behavior back.
93 set logging debugredirect [on|off]
94 By default, GDB debug output will go to both the terminal and the logfile.
95 Set if you want debug output to go only to the log file.
97 set style title foreground COLOR
98 set style title background COLOR
99 set style title intensity VALUE
100 Control the styling of titles.
102 set style highlight foreground COLOR
103 set style highlight background COLOR
104 set style highlight intensity VALUE
105 Control the styling of highlightings.
107 maint set test-settings KIND
108 maint show test-settings KIND
109 A set of commands used by the testsuite for exercising the settings
112 set print frame-info [short-location|location|location-and-address
113 |source-and-location|source-line|auto]
114 show print frame-info
115 This controls what frame information is printed by the commands printing
116 a frame. This setting will e.g. influence the behaviour of 'backtrace',
117 'frame', 'stepi'. The python frame filtering also respect this setting.
118 The 'backtrace' '-frame-info' option can override this global setting.
123 The "help" command uses the title style to enhance the
124 readibility of its output by styling the classes and
128 Similarly to "help", the "apropos" command also uses the
129 title style for the command names. "apropos" accepts now
130 a flag "-v" (verbose) to show the full documentation
131 of matching commands and to use the highlight style to mark
132 the documentation parts matching REGEXP.
136 The GDB printf and eval commands can now print C-style and Ada-style
137 string convenience variables without calling functions in the program.
138 This allows to do formatted printing of strings without having
139 a running inferior, or when debugging a core dump.
142 The "show style" and its subcommands are now styling
143 a style name in their output using its own style, to help
144 the user visualize the different styles.
146 set print frame-arguments
147 The new value 'presence' indicates to only indicate the presence of
148 arguments using ..., instead of printing argument names and values.
150 set print raw-frame-arguments
151 show print raw-frame-arguments
153 These commands replace the similarly-named "set/show print raw
154 frame-arguments" commands (now with a dash instead of a space). The
155 old commands are now deprecated and may be removed in a future
158 maint test-options require-delimiter
159 maint test-options unknown-is-error
160 maint test-options unknown-is-operand
161 maint show test-options-completion-result
162 Commands used by the testsuite to validate the command options
165 * New command options, command completion
167 GDB now has a standard infrastructure to support dash-style command
168 options ('-OPT'). One benefit is that commands that use it can
169 easily support completion of command line arguments. Try "CMD
170 -[TAB]" or "help CMD" to find options supported by a command. Over
171 time, we intend to migrate most commands to this infrastructure. A
172 number of commands got support for new command options in this
175 ** The "print" and "compile print" commands now support a number of
176 options that allow overriding relevant global print settings as
177 set by "set print" subcommands:
181 -array-indexes [on|off]
182 -elements NUMBER|unlimited
186 -repeats NUMBER|unlimited
187 -static-members [on|off]
192 Note that because the "print"/"compile print" commands accept
193 arbitrary expressions which may look like options (including
194 abbreviations), if you specify any command option, then you must
195 use a double dash ("--") to mark the end of argument processing.
197 ** The "backtrace" command now supports a number of options that
198 allow overriding relevant global print settings as set by "set
199 backtrace" and "set print" subcommands:
201 -entry-values no|only|preferred|if-needed|both|compact|default
202 -frame-arguments all|scalars|none
203 -raw-frame-arguments [on|off]
204 -frame-info auto|source-line|location|source-and-location
205 |location-and-address|short-location
209 In addition, the full/no-filters/hide qualifiers are now also
210 exposed as command options too:
216 ** The "frame apply", "tfaas" and "faas" commands similarly now
217 support the following options:
222 All options above can also be abbreviated. The argument of boolean
223 (on/off) options can be 0/1 too, and also the argument is assumed
224 "on" if omitted. This allows writing compact command invocations,
227 (gdb) p -r -p -o 0 -- *myptr
229 The above is equivalent to:
231 (gdb) print -raw -pretty -object off -- *myptr
233 ** The "info types" command now supports the '-q' flag to disable
234 printing of some header information in a similar fashion to "info
235 variables" and "info functions".
237 * Completion improvements
239 ** GDB can now complete the options of the "thread apply all" and
240 "taas" commands, and their "-ascending" option can now be
243 ** GDB can now complete the options of the "info threads", "info
244 functions", "info variables", "info locals", and "info args"
247 ** GDB can now complete the options of the "compile file" and
248 "compile code" commands. The "compile file" command now
249 completes on filenames.
251 ** GDB can now complete the backtrace command's
252 "full/no-filters/hide" qualifiers.
254 * In settings, you can now abbreviate "unlimited".
256 E.g., "set print elements u" is now equivalent to "set print
262 This lists all the possible completions for the rest of the line, if it
263 were to be given as a command itself. This is intended for use by MI
264 frontends in cases when separate CLI and MI channels cannot be used.
266 -catch-throw, -catch-rethrow, and -catch-catch
267 These can be used to catch C++ exceptions in a similar fashion to
268 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
272 The testsuite now creates the files gdb.cmd (containing the arguments
273 used to launch GDB) and gdb.in (containing all the commands sent to
274 GDB) in the output directory for each test script. Multiple invocations
275 are appended with .1, .2, .3 etc.
277 *** Changes in GDB 8.3
279 * GDB and GDBserver now support access to additional registers on
280 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
283 * GDB now has experimental support for the compilation and injection of
284 C++ source code into the inferior. This beta release does not include
285 support for several language features, such as templates, constructors,
288 This feature requires GCC 7.1 or higher built with libcp1.so
291 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
292 can be passed using the '[ADDRESS]:PORT' notation, or the regular
293 'ADDRESS:PORT' method.
295 * DWARF index cache: GDB can now automatically save indices of DWARF
296 symbols on disk to speed up further loading of the same binaries.
298 * Ada task switching is now supported on aarch64-elf targets when
299 debugging a program using the Ravenscar Profile. For more information,
300 see the "Tasking Support when using the Ravenscar Profile" section
301 in the GDB user manual.
303 * GDB in batch mode now exits with status 1 if the last command to be
306 * The RISC-V target now supports target descriptions.
308 * System call catchpoints now support system call aliases on FreeBSD.
309 When the ABI of a system call changes in FreeBSD, this is
310 implemented by leaving a compatibility system call using the old ABI
311 at the existing number and allocating a new system call number for
312 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
313 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
314 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
315 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
316 so that a system call catchpoint for the 'kevent' system call will
317 catch invocations of both the 'kevent' and 'freebsd11_kevent'
318 binaries. This ensures that 'kevent' system calls are caught for
319 binaries using either the old or new ABIs.
321 * Terminal styling is now available for the CLI and the TUI. GNU
322 Source Highlight can additionally be used to provide styling of
323 source code snippets. See the "set style" commands, below, for more
326 * Removed support for old demangling styles arm, edg, gnu, hp and
331 set debug compile-cplus-types
332 show debug compile-cplus-types
333 Control the display of debug output about type conversion in the
334 C++ compile feature. Commands have no effect while compiliong
339 Control whether debug output about files/functions skipping is
342 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
343 Apply a command to some frames.
344 FLAG arguments allow to control what output to produce and how to handle
345 errors raised when applying COMMAND to a frame.
348 Apply a command to all threads (ignoring errors and empty output).
349 Shortcut for 'thread apply all -s COMMAND'.
352 Apply a command to all frames (ignoring errors and empty output).
353 Shortcut for 'frame apply all -s COMMAND'.
356 Apply a command to all frames of all threads (ignoring errors and empty
358 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
360 maint set dwarf unwinders (on|off)
361 maint show dwarf unwinders
362 Control whether DWARF unwinders can be used.
365 Display a list of open files for a process.
369 Changes to the "frame", "select-frame", and "info frame" CLI commands.
370 These commands all now take a frame specification which
371 is either a frame level, or one of the keywords 'level', 'address',
372 'function', or 'view' followed by a parameter. Selecting a frame by
373 address, or viewing a frame outside the current backtrace now
374 requires the use of a keyword. Selecting a frame by level is
375 unchanged. The MI comment "-stack-select-frame" is unchanged.
377 target remote FILENAME
378 target extended-remote FILENAME
379 If FILENAME is a Unix domain socket, GDB will attempt to connect
380 to this socket instead of opening FILENAME as a character device.
382 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
383 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
384 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
385 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
386 These commands can now print only the searched entities
387 matching the provided regexp(s), giving a condition
388 on the entity names or entity types. The flag -q disables
389 printing headers or informations messages.
395 These commands now determine the syntax for the shown entities
396 according to the language chosen by `set language'. In particular,
397 `set language auto' means to automatically choose the language of
400 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
401 The 'thread apply' command accepts new FLAG arguments.
402 FLAG arguments allow to control what output to produce and how to handle
403 errors raised when applying COMMAND to a thread.
405 set tui tab-width NCHARS
406 show tui tab-width NCHARS
407 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
409 set style enabled [on|off]
411 Enable or disable terminal styling. Styling is enabled by default
412 on most hosts, but disabled by default when in batch mode.
414 set style sources [on|off]
416 Enable or disable source code styling. Source code styling is
417 enabled by default, but only takes effect if styling in general is
418 enabled, and if GDB was linked with GNU Source Highlight.
420 set style filename foreground COLOR
421 set style filename background COLOR
422 set style filename intensity VALUE
423 Control the styling of file names.
425 set style function foreground COLOR
426 set style function background COLOR
427 set style function intensity VALUE
428 Control the styling of function names.
430 set style variable foreground COLOR
431 set style variable background COLOR
432 set style variable intensity VALUE
433 Control the styling of variable names.
435 set style address foreground COLOR
436 set style address background COLOR
437 set style address intensity VALUE
438 Control the styling of addresses.
442 ** The default version of the MI interpreter is now 3 (-i=mi3).
444 ** The '-data-disassemble' MI command now accepts an '-a' option to
445 disassemble the whole function surrounding the given program
446 counter value or function name. Support for this feature can be
447 verified by using the "-list-features" command, which should
448 contain "data-disassemble-a-option".
450 ** Command responses and notifications that include a frame now include
451 the frame's architecture in a new "arch" attribute.
453 ** The output of information about multi-location breakpoints (which is
454 syntactically incorrect in MI 2) has changed in MI 3. This affects
455 the following commands and events:
459 - =breakpoint-created
460 - =breakpoint-modified
462 The -fix-multi-location-breakpoint-output command can be used to enable
463 this behavior with previous MI versions.
465 * New native configurations
467 GNU/Linux/RISC-V riscv*-*-linux*
468 FreeBSD/riscv riscv*-*-freebsd*
472 GNU/Linux/RISC-V riscv*-*-linux*
474 CSKY GNU/LINUX csky*-*-linux
475 FreeBSD/riscv riscv*-*-freebsd*
477 GNU/Linux/OpenRISC or1k*-*-linux*
481 GDB no longer supports native debugging on versions of MS-Windows
486 ** GDB no longer supports Python versions less than 2.6.
488 ** The gdb.Inferior type has a new 'progspace' property, which is the program
489 space associated to that inferior.
491 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
492 of objfiles associated to that program space.
494 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
495 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
498 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
499 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
500 correct and did not work properly.
502 ** The gdb.Value type has a new constructor, which is used to construct a
503 gdb.Value from a Python buffer object and a gdb.Type.
509 Enable or disable the undefined behavior sanitizer. This is
510 disabled by default, but passing --enable-ubsan=yes or
511 --enable-ubsan=auto to configure will enable it. Enabling this can
512 cause a performance penalty. The undefined behavior sanitizer was
513 first introduced in GCC 4.9.
515 *** Changes in GDB 8.2
517 * The 'set disassembler-options' command now supports specifying options
520 * The 'symbol-file' command now accepts an '-o' option to add a relative
521 offset to all sections.
523 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
524 a relative offset to all sections, but it allows to override the load
525 address of individual sections using '-s'.
527 * The 'add-symbol-file' command no longer requires the second argument
528 (address of the text section).
530 * The endianness used with the 'set endian auto' mode in the absence of
531 an executable selected for debugging is now the last endianness chosen
532 either by one of the 'set endian big' and 'set endian little' commands
533 or by inferring from the last executable used, rather than the startup
536 * The pager now allows a "c" response, meaning to disable the pager
537 for the rest of the current command.
539 * The commands 'info variables/functions/types' now show the source line
540 numbers of symbol definitions when available.
542 * 'info proc' now works on running processes on FreeBSD systems and core
543 files created on FreeBSD systems.
545 * C expressions can now use _Alignof, and C++ expressions can now use
548 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
549 the vector length while the process is running.
555 Control display of debugging info regarding the FreeBSD native target.
557 set|show varsize-limit
558 This new setting allows the user to control the maximum size of Ada
559 objects being printed when those objects have a variable type,
560 instead of that maximum size being hardcoded to 65536 bytes.
562 set|show record btrace cpu
563 Controls the processor to be used for enabling errata workarounds for
566 maint check libthread-db
567 Run integrity checks on the current inferior's thread debugging
570 maint set check-libthread-db (on|off)
571 maint show check-libthread-db
572 Control whether to run integrity checks on inferior specific thread
573 debugging libraries as they are loaded. The default is not to
578 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
580 ** The commands attached to a breakpoint can be set by assigning to
581 the breakpoint's "commands" field.
583 ** gdb.execute can now execute multi-line gdb commands.
585 ** The new functions gdb.convenience_variable and
586 gdb.set_convenience_variable can be used to get and set the value
587 of convenience variables.
589 ** A gdb.Parameter will no longer print the "set" help text on an
590 ordinary "set"; instead by default a "set" will be silent unless
591 the get_set_string method returns a non-empty string.
595 RiscV ELF riscv*-*-elf
597 * Removed targets and native configurations
599 m88k running OpenBSD m88*-*-openbsd*
600 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
601 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
602 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
604 * Aarch64/Linux hardware watchpoints improvements
606 Hardware watchpoints on unaligned addresses are now properly
607 supported when running Linux kernel 4.10 or higher: read and access
608 watchpoints are no longer spuriously missed, and all watchpoints
609 lengths between 1 and 8 bytes are supported. On older kernels,
610 watchpoints set on unaligned addresses are no longer missed, with
611 the tradeoff that there is a possibility of false hits being
616 --enable-codesign=CERT
617 This can be used to invoke "codesign -s CERT" after building gdb.
618 This option is useful on macOS, where code signing is required for
619 gdb to work properly.
621 --disable-gdbcli has been removed
622 This is now silently accepted, but does nothing.
624 *** Changes in GDB 8.1
626 * GDB now supports dynamically creating arbitrary register groups specified
627 in XML target descriptions. This allows for finer grain grouping of
628 registers on systems with a large amount of registers.
630 * The 'ptype' command now accepts a '/o' flag, which prints the
631 offsets and sizes of fields in a struct, like the pahole(1) tool.
633 * New "--readnever" command line option instructs GDB to not read each
634 symbol file's symbolic debug information. This makes startup faster
635 but at the expense of not being able to perform symbolic debugging.
636 This option is intended for use cases where symbolic debugging will
637 not be used, e.g., when you only need to dump the debuggee's core.
639 * GDB now uses the GNU MPFR library, if available, to emulate target
640 floating-point arithmetic during expression evaluation when the target
641 uses different floating-point formats than the host. At least version
642 3.1 of GNU MPFR is required.
644 * GDB now supports access to the guarded-storage-control registers and the
645 software-based guarded-storage broadcast control registers on IBM z14.
647 * On Unix systems, GDB now supports transmitting environment variables
648 that are to be set or unset to GDBserver. These variables will
649 affect the environment to be passed to the remote inferior.
651 To inform GDB of environment variables that are to be transmitted to
652 GDBserver, use the "set environment" command. Only user set
653 environment variables are sent to GDBserver.
655 To inform GDB of environment variables that are to be unset before
656 the remote inferior is started by the GDBserver, use the "unset
657 environment" command.
659 * Completion improvements
661 ** GDB can now complete function parameters in linespecs and
662 explicit locations without quoting. When setting breakpoints,
663 quoting around functions names to help with TAB-completion is
664 generally no longer necessary. For example, this now completes
667 (gdb) b function(in[TAB]
668 (gdb) b function(int)
670 Related, GDB is no longer confused with completing functions in
671 C++ anonymous namespaces:
674 (gdb) b (anonymous namespace)::[TAB][TAB]
675 (anonymous namespace)::a_function()
676 (anonymous namespace)::b_function()
678 ** GDB now has much improved linespec and explicit locations TAB
679 completion support, that better understands what you're
680 completing and offers better suggestions. For example, GDB no
681 longer offers data symbols as possible completions when you're
682 setting a breakpoint.
684 ** GDB now TAB-completes label symbol names.
686 ** The "complete" command now mimics TAB completion accurately.
688 * New command line options (gcore)
691 Dump all memory mappings.
693 * Breakpoints on C++ functions are now set on all scopes by default
695 By default, breakpoints on functions/methods are now interpreted as
696 specifying all functions with the given name ignoring missing
697 leading scopes (namespaces and classes).
699 For example, assuming a C++ program with symbols named:
704 both commands "break func()" and "break B::func()" set a breakpoint
707 You can use the new flag "-qualified" to override this. This makes
708 GDB interpret the specified function name as a complete
709 fully-qualified name instead. For example, using the same C++
710 program, the "break -q B::func" command sets a breakpoint on
711 "B::func", only. A parameter has been added to the Python
712 gdb.Breakpoint constructor to achieve the same result when creating
713 a breakpoint from Python.
715 * Breakpoints on functions marked with C++ ABI tags
717 GDB can now set breakpoints on functions marked with C++ ABI tags
718 (e.g., [abi:cxx11]). See here for a description of ABI tags:
719 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
721 Functions with a C++11 abi tag are demangled/displayed like this:
723 function[abi:cxx11](int)
726 You can now set a breakpoint on such functions simply as if they had
729 (gdb) b function(int)
731 Or if you need to disambiguate between tags, like:
733 (gdb) b function[abi:other_tag](int)
735 Tab completion was adjusted accordingly as well.
739 ** New events gdb.new_inferior, gdb.inferior_deleted, and
740 gdb.new_thread are emitted. See the manual for further
741 description of these.
743 ** A new function, "gdb.rbreak" has been added to the Python API.
744 This function allows the setting of a large number of breakpoints
745 via a regex pattern in Python. See the manual for further details.
747 ** Python breakpoints can now accept explicit locations. See the
748 manual for a further description of this feature.
751 * New features in the GDB remote stub, GDBserver
753 ** GDBserver is now able to start inferior processes with a
754 specified initial working directory.
756 The user can set the desired working directory to be used from
757 GDB using the new "set cwd" command.
759 ** New "--selftest" command line option runs some GDBserver self
760 tests. These self tests are disabled in releases.
762 ** On Unix systems, GDBserver now does globbing expansion and variable
763 substitution in inferior command line arguments.
765 This is done by starting inferiors using a shell, like GDB does.
766 See "set startup-with-shell" in the user manual for how to disable
767 this from GDB when using "target extended-remote". When using
768 "target remote", you can disable the startup with shell by using the
769 new "--no-startup-with-shell" GDBserver command line option.
771 ** On Unix systems, GDBserver now supports receiving environment
772 variables that are to be set or unset from GDB. These variables
773 will affect the environment to be passed to the inferior.
775 * When catching an Ada exception raised with a message, GDB now prints
776 the message in the catchpoint hit notification. In GDB/MI mode, that
777 information is provided as an extra field named "exception-message"
778 in the *stopped notification.
780 * Trait objects can now be inspected When debugging Rust code. This
781 requires compiler support which will appear in Rust 1.24.
785 QEnvironmentHexEncoded
786 Inform GDBserver of an environment variable that is to be passed to
787 the inferior when starting it.
790 Inform GDBserver of an environment variable that is to be unset
791 before starting the remote inferior.
794 Inform GDBserver that the environment should be reset (i.e.,
795 user-set environment variables should be unset).
798 Indicates whether the inferior must be started with a shell or not.
801 Tell GDBserver that the inferior to be started should use a specific
804 * The "maintenance print c-tdesc" command now takes an optional
805 argument which is the file name of XML target description.
807 * The "maintenance selftest" command now takes an optional argument to
808 filter the tests to be run.
810 * The "enable", and "disable" commands now accept a range of
811 breakpoint locations, e.g. "enable 1.3-5".
816 Set and show the current working directory for the inferior.
819 Set and show compilation command used for compiling and injecting code
820 with the 'compile' commands.
822 set debug separate-debug-file
823 show debug separate-debug-file
824 Control the display of debug output about separate debug file search.
826 set dump-excluded-mappings
827 show dump-excluded-mappings
828 Control whether mappings marked with the VM_DONTDUMP flag should be
829 dumped when generating a core file.
832 List the registered selftests.
835 Start the debugged program stopping at the first instruction.
838 Control display of debugging messages related to OpenRISC targets.
840 set|show print type nested-type-limit
841 Set and show the limit of nesting level for nested types that the
842 type printer will show.
844 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
847 * Safer/improved support for debugging with no debug info
849 GDB no longer assumes functions with no debug information return
852 This means that GDB now refuses to call such functions unless you
853 tell it the function's type, by either casting the call to the
854 declared return type, or by casting the function to a function
855 pointer of the right type, and calling that:
857 (gdb) p getenv ("PATH")
858 'getenv' has unknown return type; cast the call to its declared return type
859 (gdb) p (char *) getenv ("PATH")
860 $1 = 0x7fffffffe "/usr/local/bin:/"...
861 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
862 $2 = 0x7fffffffe "/usr/local/bin:/"...
864 Similarly, GDB no longer assumes that global variables with no debug
865 info have type 'int', and refuses to print the variable's value
866 unless you tell it the variable's type:
869 'var' has unknown type; cast it to its declared type
873 * New native configurations
875 FreeBSD/aarch64 aarch64*-*-freebsd*
876 FreeBSD/arm arm*-*-freebsd*
880 FreeBSD/aarch64 aarch64*-*-freebsd*
881 FreeBSD/arm arm*-*-freebsd*
882 OpenRISC ELF or1k*-*-elf
884 * Removed targets and native configurations
886 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
888 *** Changes in GDB 8.0
890 * GDB now supports access to the PKU register on GNU/Linux. The register is
891 added by the Memory Protection Keys for Userspace feature which will be
892 available in future Intel CPUs.
894 * GDB now supports C++11 rvalue references.
898 ** New functions to start, stop and access a running btrace recording.
899 ** Rvalue references are now supported in gdb.Type.
901 * GDB now supports recording and replaying rdrand and rdseed Intel 64
904 * Building GDB and GDBserver now requires a C++11 compiler.
906 For example, GCC 4.8 or later.
908 It is no longer possible to build GDB or GDBserver with a C
909 compiler. The --disable-build-with-cxx configure option has been
912 * Building GDB and GDBserver now requires GNU make >= 3.81.
914 It is no longer supported to build GDB or GDBserver with another
915 implementation of the make program or an earlier version of GNU make.
917 * Native debugging on MS-Windows supports command-line redirection
919 Command-line arguments used for starting programs on MS-Windows can
920 now include redirection symbols supported by native Windows shells,
921 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
922 as "run", "start", and "set args", as well as the corresponding MI
925 * Support for thread names on MS-Windows.
927 GDB now catches and handles the special exception that programs
928 running on MS-Windows use to assign names to threads in the
931 * Support for Java programs compiled with gcj has been removed.
933 * User commands now accept an unlimited number of arguments.
934 Previously, only up to 10 was accepted.
936 * The "eval" command now expands user-defined command arguments.
938 This makes it easier to process a variable number of arguments:
943 eval "print $arg%d", $i
948 * Target descriptions can now describe registers for sparc32 and sparc64.
950 * GDB now supports DWARF version 5 (debug information format).
951 Its .debug_names index is not yet supported.
953 * New native configurations
955 FreeBSD/mips mips*-*-freebsd
959 Synopsys ARC arc*-*-elf32
960 FreeBSD/mips mips*-*-freebsd
962 * Removed targets and native configurations
964 Alpha running FreeBSD alpha*-*-freebsd*
965 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
970 Erases all the flash memory regions reported by the target.
972 maint print arc arc-instruction address
973 Print internal disassembler information about instruction at a given address.
977 set disassembler-options
978 show disassembler-options
979 Controls the passing of target specific information to the disassembler.
980 If it is necessary to specify more than one disassembler option then
981 multiple options can be placed together into a comma separated list.
982 The default value is the empty string. Currently, the only supported
983 targets are ARM, PowerPC and S/390.
988 Erases all the flash memory regions reported by the target. This is
989 equivalent to the CLI command flash-erase.
991 -file-list-shared-libraries
992 List the shared libraries in the program. This is
993 equivalent to the CLI command "info shared".
996 Catchpoints stopping the program when Ada exceptions are
997 handled. This is equivalent to the CLI command "catch handlers".
999 *** Changes in GDB 7.12
1001 * GDB and GDBserver now build with a C++ compiler by default.
1003 The --enable-build-with-cxx configure option is now enabled by
1004 default. One must now explicitly configure with
1005 --disable-build-with-cxx in order to build with a C compiler. This
1006 option will be removed in a future release.
1008 * GDBserver now supports recording btrace without maintaining an active
1011 * GDB now supports a negative repeat count in the 'x' command to examine
1012 memory backward from the given address. For example:
1015 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1016 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1017 (gdb) x/-5i 0x0000000000400580
1018 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1019 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1020 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1021 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1022 0x40057b <main(int, char**)+25>:
1023 callq 0x400536 <Func1(int, char const*)>
1025 * Fortran: Support structures with fields of dynamic types and
1026 arrays of dynamic types.
1028 * The symbol dumping maintenance commands have new syntax.
1029 maint print symbols [-pc address] [--] [filename]
1030 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1031 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1032 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1033 maint print msymbols [-objfile objfile] [--] [filename]
1035 * GDB now supports multibit bitfields and enums in target register
1038 * New Python-based convenience function $_as_string(val), which returns
1039 the textual representation of a value. This function is especially
1040 useful to obtain the text label of an enum value.
1042 * Intel MPX bound violation handling.
1044 Segmentation faults caused by a Intel MPX boundary violation
1045 now display the kind of violation (upper or lower), the memory
1046 address accessed and the memory bounds, along with the usual
1047 signal received and code location.
1051 Program received signal SIGSEGV, Segmentation fault
1052 Upper bound violation while accessing address 0x7fffffffc3b3
1053 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1054 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1056 * Rust language support.
1057 GDB now supports debugging programs written in the Rust programming
1058 language. See https://www.rust-lang.org/ for more information about
1061 * Support for running interpreters on specified input/output devices
1063 GDB now supports a new mechanism that allows frontends to provide
1064 fully featured GDB console views, as a better alternative to
1065 building such views on top of the "-interpreter-exec console"
1066 command. See the new "new-ui" command below. With that command,
1067 frontends can now start GDB in the traditional command-line mode
1068 running in an embedded terminal emulator widget, and create a
1069 separate MI interpreter running on a specified i/o device. In this
1070 way, GDB handles line editing, history, tab completion, etc. in the
1071 console all by itself, and the GUI uses the separate MI interpreter
1072 for its own control and synchronization, invisible to the command
1075 * The "catch syscall" command catches groups of related syscalls.
1077 The "catch syscall" command now supports catching a group of related
1078 syscalls using the 'group:' or 'g:' prefix.
1083 skip -gfile file-glob-pattern
1084 skip -function function
1085 skip -rfunction regular-expression
1086 A generalized form of the skip command, with new support for
1087 glob-style file names and regular expressions for function names.
1088 Additionally, a file spec and a function spec may now be combined.
1090 maint info line-table REGEXP
1091 Display the contents of GDB's internal line table data struture.
1094 Run any GDB unit tests that were compiled in.
1097 Start a new user interface instance running INTERP as interpreter,
1098 using the TTY file for input/output.
1102 ** gdb.Breakpoint objects have a new attribute "pending", which
1103 indicates whether the breakpoint is pending.
1104 ** Three new breakpoint-related events have been added:
1105 gdb.breakpoint_created, gdb.breakpoint_modified, and
1106 gdb.breakpoint_deleted.
1108 signal-event EVENTID
1109 Signal ("set") the given MS-Windows event object. This is used in
1110 conjunction with the Windows JIT debugging (AeDebug) support, where
1111 the OS suspends a crashing process until a debugger can attach to
1112 it. Resuming the crashing process, in order to debug it, is done by
1113 signalling an event.
1115 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1116 was added in GDBserver, including JIT compiling fast tracepoint's
1117 conditional expression bytecode into native code.
1119 * Support for various remote target protocols and ROM monitors has
1122 target m32rsdi Remote M32R debugging over SDI
1123 target mips MIPS remote debugging protocol
1124 target pmon PMON ROM monitor
1125 target ddb NEC's DDB variant of PMON for Vr4300
1126 target rockhopper NEC RockHopper variant of PMON
1127 target lsi LSI variant of PMO
1129 * Support for tracepoints and fast tracepoints on powerpc-linux,
1130 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1131 including JIT compiling fast tracepoint's conditional expression
1132 bytecode into native code.
1134 * MI async record =record-started now includes the method and format used for
1135 recording. For example:
1137 =record-started,thread-group="i1",method="btrace",format="bts"
1139 * MI async record =thread-selected now includes the frame field. For example:
1141 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1145 Andes NDS32 nds32*-*-elf
1147 *** Changes in GDB 7.11
1149 * GDB now supports debugging kernel-based threads on FreeBSD.
1151 * Per-inferior thread numbers
1153 Thread numbers are now per inferior instead of global. If you're
1154 debugging multiple inferiors, GDB displays thread IDs using a
1155 qualified INF_NUM.THR_NUM form. For example:
1159 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1160 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1161 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1162 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1164 As consequence, thread numbers as visible in the $_thread
1165 convenience variable and in Python's InferiorThread.num attribute
1166 are no longer unique between inferiors.
1168 GDB now maintains a second thread ID per thread, referred to as the
1169 global thread ID, which is the new equivalent of thread numbers in
1170 previous releases. See also $_gthread below.
1172 For backwards compatibility, MI's thread IDs always refer to global
1175 * Commands that accept thread IDs now accept the qualified
1176 INF_NUM.THR_NUM form as well. For example:
1179 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1182 * In commands that accept a list of thread IDs, you can now refer to
1183 all threads of an inferior using a star wildcard. GDB accepts
1184 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1185 refer to all threads of the current inferior. For example, "info
1188 * You can use "info threads -gid" to display the global thread ID of
1191 * The new convenience variable $_gthread holds the global number of
1194 * The new convenience variable $_inferior holds the number of the
1197 * GDB now displays the ID and name of the thread that hit a breakpoint
1198 or received a signal, if your program is multi-threaded. For
1201 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1202 Thread 1 "main" received signal SIGINT, Interrupt.
1204 * Record btrace now supports non-stop mode.
1206 * Support for tracepoints on aarch64-linux was added in GDBserver.
1208 * The 'record instruction-history' command now indicates speculative execution
1209 when using the Intel Processor Trace recording format.
1211 * GDB now allows users to specify explicit locations, bypassing
1212 the linespec parser. This feature is also available to GDB/MI
1215 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1216 GDB now is able to debug both AArch64 applications and ARM applications
1219 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1220 including JIT compiling fast tracepoint's conditional expression bytecode
1223 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1225 * "info threads", "info inferiors", "info display", "info checkpoints"
1226 and "maint info program-spaces" now list the corresponding items in
1227 ascending ID order, for consistency with all other "info" commands.
1229 * In Ada, the overloads selection menu has been enhanced to display the
1230 parameter types and the return types for the matching overloaded subprograms.
1234 maint set target-non-stop (on|off|auto)
1235 maint show target-non-stop
1236 Control whether GDB targets always operate in non-stop mode even if
1237 "set non-stop" is "off". The default is "auto", meaning non-stop
1238 mode is enabled if supported by the target.
1240 maint set bfd-sharing
1241 maint show bfd-sharing
1242 Control the reuse of bfd objects.
1245 show debug bfd-cache
1246 Control display of debugging info regarding bfd caching.
1250 Control display of debugging info regarding FreeBSD threads.
1252 set remote multiprocess-extensions-packet
1253 show remote multiprocess-extensions-packet
1254 Set/show the use of the remote protocol multiprocess extensions.
1256 set remote thread-events
1257 show remote thread-events
1258 Set/show the use of thread create/exit events.
1260 set ada print-signatures on|off
1261 show ada print-signatures"
1262 Control whether parameter types and return types are displayed in overloads
1263 selection menus. It is activaled (@code{on}) by default.
1267 Controls the maximum size of memory, in bytes, that GDB will
1268 allocate for value contents. Prevents incorrect programs from
1269 causing GDB to allocate overly large buffers. Default is 64k.
1271 * The "disassemble" command accepts a new modifier: /s.
1272 It prints mixed source+disassembly like /m with two differences:
1273 - disassembled instructions are now printed in program order, and
1274 - and source for all relevant files is now printed.
1275 The "/m" option is now considered deprecated: its "source-centric"
1276 output hasn't proved useful in practice.
1278 * The "record instruction-history" command accepts a new modifier: /s.
1279 It behaves exactly like /m and prints mixed source+disassembly.
1281 * The "set scheduler-locking" command supports a new mode "replay".
1282 It behaves like "off" in record mode and like "on" in replay mode.
1284 * Support for various ROM monitors has been removed:
1286 target dbug dBUG ROM monitor for Motorola ColdFire
1287 target picobug Motorola picobug monitor
1288 target dink32 DINK32 ROM monitor for PowerPC
1289 target m32r Renesas M32R/D ROM monitor
1290 target mon2000 mon2000 ROM monitor
1291 target ppcbug PPCBUG ROM monitor for PowerPC
1293 * Support for reading/writing memory and extracting values on architectures
1294 whose memory is addressable in units of any integral multiple of 8 bits.
1297 Allows to break when an Ada exception is handled.
1299 * New remote packets
1302 Indicates that an exec system call was executed.
1304 exec-events feature in qSupported
1305 The qSupported packet allows GDB to request support for exec
1306 events using the new 'gdbfeature' exec-event, and the qSupported
1307 response can contain the corresponding 'stubfeature'. Set and
1308 show commands can be used to display whether these features are enabled.
1311 Equivalent to interrupting with the ^C character, but works in
1314 thread created stop reason (T05 create:...)
1315 Indicates that the thread was just created and is stopped at entry.
1317 thread exit stop reply (w exitcode;tid)
1318 Indicates that the thread has terminated.
1321 Enables/disables thread create and exit event reporting. For
1322 example, this is used in non-stop mode when GDB stops a set of
1323 threads and synchronously waits for the their corresponding stop
1324 replies. Without exit events, if one of the threads exits, GDB
1325 would hang forever not knowing that it should no longer expect a
1326 stop for that same thread.
1329 Indicates that there are no resumed threads left in the target (all
1330 threads are stopped). The remote stub reports support for this stop
1331 reply to GDB's qSupported query.
1334 Enables/disables catching syscalls from the inferior process.
1335 The remote stub reports support for this packet to GDB's qSupported query.
1337 syscall_entry stop reason
1338 Indicates that a syscall was just called.
1340 syscall_return stop reason
1341 Indicates that a syscall just returned.
1343 * Extended-remote exec events
1345 ** GDB now has support for exec events on extended-remote Linux targets.
1346 For such targets with Linux kernels 2.5.46 and later, this enables
1347 follow-exec-mode and exec catchpoints.
1349 set remote exec-event-feature-packet
1350 show remote exec-event-feature-packet
1351 Set/show the use of the remote exec event feature.
1353 * Thread names in remote protocol
1355 The reply to qXfer:threads:read may now include a name attribute for each
1358 * Target remote mode fork and exec events
1360 ** GDB now has support for fork and exec events on target remote mode
1361 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1362 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1363 fork and exec catchpoints.
1365 * Remote syscall events
1367 ** GDB now has support for catch syscall on remote Linux targets,
1368 currently enabled on x86/x86_64 architectures.
1370 set remote catch-syscall-packet
1371 show remote catch-syscall-packet
1372 Set/show the use of the remote catch syscall feature.
1376 ** The -var-set-format command now accepts the zero-hexadecimal
1377 format. It outputs data in hexadecimal format with zero-padding on the
1382 ** gdb.InferiorThread objects have a new attribute "global_num",
1383 which refers to the thread's global thread ID. The existing
1384 "num" attribute now refers to the thread's per-inferior number.
1385 See "Per-inferior thread numbers" above.
1386 ** gdb.InferiorThread objects have a new attribute "inferior", which
1387 is the Inferior object the thread belongs to.
1389 *** Changes in GDB 7.10
1391 * Support for process record-replay and reverse debugging on aarch64*-linux*
1392 targets has been added. GDB now supports recording of A64 instruction set
1393 including advance SIMD instructions.
1395 * Support for Sun's version of the "stabs" debug file format has been removed.
1397 * GDB now honors the content of the file /proc/PID/coredump_filter
1398 (PID is the process ID) on GNU/Linux systems. This file can be used
1399 to specify the types of memory mappings that will be included in a
1400 corefile. For more information, please refer to the manual page of
1401 "core(5)". GDB also has a new command: "set use-coredump-filter
1402 on|off". It allows to set whether GDB will read the content of the
1403 /proc/PID/coredump_filter file when generating a corefile.
1405 * The "info os" command on GNU/Linux can now display information on
1407 "info os cpus" Listing of all cpus/cores on the system
1409 * GDB has two new commands: "set serial parity odd|even|none" and
1410 "show serial parity". These allows to set or show parity for the
1413 * The "info source" command now displays the producer string if it was
1414 present in the debug info. This typically includes the compiler version
1415 and may include things like its command line arguments.
1417 * The "info dll", an alias of the "info sharedlibrary" command,
1418 is now available on all platforms.
1420 * Directory names supplied to the "set sysroot" commands may be
1421 prefixed with "target:" to tell GDB to access shared libraries from
1422 the target system, be it local or remote. This replaces the prefix
1423 "remote:". The default sysroot has been changed from "" to
1424 "target:". "remote:" is automatically converted to "target:" for
1425 backward compatibility.
1427 * The system root specified by "set sysroot" will be prepended to the
1428 filename of the main executable (if reported to GDB as absolute by
1429 the operating system) when starting processes remotely, and when
1430 attaching to already-running local or remote processes.
1432 * GDB now supports automatic location and retrieval of executable
1433 files from remote targets. Remote debugging can now be initiated
1434 using only a "target remote" or "target extended-remote" command
1435 (no "set sysroot" or "file" commands are required). See "New remote
1438 * The "dump" command now supports verilog hex format.
1440 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1442 * On GNU/Linux, GDB and gdbserver are now able to access executable
1443 and shared library files without a "set sysroot" command when
1444 attaching to processes running in different mount namespaces from
1445 the debugger. This makes it possible to attach to processes in
1446 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1447 See "New remote packets" below.
1449 * The "tui reg" command now provides completion for all of the
1450 available register groups, including target specific groups.
1452 * The HISTSIZE environment variable is no longer read when determining
1453 the size of GDB's command history. GDB now instead reads the dedicated
1454 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1455 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1460 ** Memory ports can now be unbuffered.
1464 ** gdb.Objfile objects have a new attribute "username",
1465 which is the name of the objfile as specified by the user,
1466 without, for example, resolving symlinks.
1467 ** You can now write frame unwinders in Python.
1468 ** gdb.Type objects have a new method "optimized_out",
1469 returning optimized out gdb.Value instance of this type.
1470 ** gdb.Value objects have new methods "reference_value" and
1471 "const_value" which return a reference to the value and a
1472 "const" version of the value respectively.
1476 maint print symbol-cache
1477 Print the contents of the symbol cache.
1479 maint print symbol-cache-statistics
1480 Print statistics of symbol cache usage.
1482 maint flush-symbol-cache
1483 Flush the contents of the symbol cache.
1487 Start branch trace recording using Branch Trace Store (BTS) format.
1490 Evaluate expression by using the compiler and print result.
1494 Explicit commands for enabling and disabling tui mode.
1497 set mpx bound on i386 and amd64
1498 Support for bound table investigation on Intel MPX enabled applications.
1502 Start branch trace recording using Intel Processor Trace format.
1505 Print information about branch tracing internals.
1507 maint btrace packet-history
1508 Print the raw branch tracing data.
1510 maint btrace clear-packet-history
1511 Discard the stored raw branch tracing data.
1514 Discard all branch tracing data. It will be fetched and processed
1515 anew by the next "record" command.
1520 Renamed from "set debug dwarf2-die".
1521 show debug dwarf-die
1522 Renamed from "show debug dwarf2-die".
1524 set debug dwarf-read
1525 Renamed from "set debug dwarf2-read".
1526 show debug dwarf-read
1527 Renamed from "show debug dwarf2-read".
1529 maint set dwarf always-disassemble
1530 Renamed from "maint set dwarf2 always-disassemble".
1531 maint show dwarf always-disassemble
1532 Renamed from "maint show dwarf2 always-disassemble".
1534 maint set dwarf max-cache-age
1535 Renamed from "maint set dwarf2 max-cache-age".
1536 maint show dwarf max-cache-age
1537 Renamed from "maint show dwarf2 max-cache-age".
1539 set debug dwarf-line
1540 show debug dwarf-line
1541 Control display of debugging info regarding DWARF line processing.
1544 show max-completions
1545 Set the maximum number of candidates to be considered during
1546 completion. The default value is 200. This limit allows GDB
1547 to avoid generating large completion lists, the computation of
1548 which can cause the debugger to become temporarily unresponsive.
1550 set history remove-duplicates
1551 show history remove-duplicates
1552 Control the removal of duplicate history entries.
1554 maint set symbol-cache-size
1555 maint show symbol-cache-size
1556 Control the size of the symbol cache.
1558 set|show record btrace bts buffer-size
1559 Set and show the size of the ring buffer used for branch tracing in
1561 The obtained size may differ from the requested size. Use "info
1562 record" to see the obtained buffer size.
1564 set debug linux-namespaces
1565 show debug linux-namespaces
1566 Control display of debugging info regarding Linux namespaces.
1568 set|show record btrace pt buffer-size
1569 Set and show the size of the ring buffer used for branch tracing in
1570 Intel Processor Trace format.
1571 The obtained size may differ from the requested size. Use "info
1572 record" to see the obtained buffer size.
1574 maint set|show btrace pt skip-pad
1575 Set and show whether PAD packets are skipped when computing the
1578 * The command 'thread apply all' can now support new option '-ascending'
1579 to call its specified command for all threads in ascending order.
1581 * Python/Guile scripting
1583 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1584 special section named `.debug_gdb_scripts'.
1586 * New remote packets
1588 qXfer:btrace-conf:read
1589 Return the branch trace configuration for the current thread.
1591 Qbtrace-conf:bts:size
1592 Set the requested ring buffer size for branch tracing in BTS format.
1595 Enable Intel Procesor Trace-based branch tracing for the current
1596 process. The remote stub reports support for this packet to GDB's
1599 Qbtrace-conf:pt:size
1600 Set the requested ring buffer size for branch tracing in Intel Processor
1604 Indicates a memory breakpoint instruction was executed, irrespective
1605 of whether it was GDB that planted the breakpoint or the breakpoint
1606 is hardcoded in the program. This is required for correct non-stop
1610 Indicates the target stopped for a hardware breakpoint. This is
1611 required for correct non-stop mode operation.
1614 Return information about files on the remote system.
1616 qXfer:exec-file:read
1617 Return the full absolute name of the file that was executed to
1618 create a process running on the remote system.
1621 Select the filesystem on which vFile: operations with filename
1622 arguments will operate. This is required for GDB to be able to
1623 access files on remote targets where the remote stub does not
1624 share a common filesystem with the inferior(s).
1627 Indicates that a fork system call was executed.
1630 Indicates that a vfork system call was executed.
1632 vforkdone stop reason
1633 Indicates that a vfork child of the specified process has executed
1634 an exec or exit, allowing the vfork parent to resume execution.
1636 fork-events and vfork-events features in qSupported
1637 The qSupported packet allows GDB to request support for fork and
1638 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1639 and the qSupported response can contain the corresponding
1640 'stubfeatures'. Set and show commands can be used to display
1641 whether these features are enabled.
1643 * Extended-remote fork events
1645 ** GDB now has support for fork events on extended-remote Linux
1646 targets. For targets with Linux kernels 2.5.60 and later, this
1647 enables follow-fork-mode and detach-on-fork for both fork and
1648 vfork, as well as fork and vfork catchpoints.
1650 * The info record command now shows the recording format and the
1651 branch tracing configuration for the current thread when using
1652 the btrace record target.
1653 For the BTS format, it shows the ring buffer size.
1655 * GDB now has support for DTrace USDT (Userland Static Defined
1656 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1658 * GDB now supports access to vector registers on S/390 GNU/Linux
1661 * Removed command line options
1663 -xdb HP-UX XDB compatibility mode.
1665 * Removed targets and native configurations
1667 HP/PA running HP-UX hppa*-*-hpux*
1668 Itanium running HP-UX ia64-*-hpux*
1670 * New configure options
1673 This configure option allows the user to build GDB with support for
1674 Intel Processor Trace (default: auto). This requires libipt.
1676 --with-libipt-prefix=PATH
1677 Specify the path to the version of libipt that GDB should use.
1678 $PATH/include should contain the intel-pt.h header and
1679 $PATH/lib should contain the libipt.so library.
1681 *** Changes in GDB 7.9.1
1685 ** Xmethods can now specify a result type.
1687 *** Changes in GDB 7.9
1689 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1693 ** You can now access frame registers from Python scripts.
1694 ** New attribute 'producer' for gdb.Symtab objects.
1695 ** gdb.Objfile objects have a new attribute "progspace",
1696 which is the gdb.Progspace object of the containing program space.
1697 ** gdb.Objfile objects have a new attribute "owner".
1698 ** gdb.Objfile objects have a new attribute "build_id",
1699 which is the build ID generated when the file was built.
1700 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1701 ** A new event "gdb.clear_objfiles" has been added, triggered when
1702 selecting a new file to debug.
1703 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1704 ** New function gdb.lookup_objfile.
1706 New events which are triggered when GDB modifies the state of the
1709 ** gdb.events.inferior_call_pre: Function call is about to be made.
1710 ** gdb.events.inferior_call_post: Function call has just been made.
1711 ** gdb.events.memory_changed: A memory location has been altered.
1712 ** gdb.events.register_changed: A register has been altered.
1714 * New Python-based convenience functions:
1716 ** $_caller_is(name [, number_of_frames])
1717 ** $_caller_matches(regexp [, number_of_frames])
1718 ** $_any_caller_is(name [, number_of_frames])
1719 ** $_any_caller_matches(regexp [, number_of_frames])
1721 * GDB now supports the compilation and injection of source code into
1722 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1723 to compile the source code to object code, and if successful, inject
1724 and execute that code within the current context of the inferior.
1725 Currently the C language is supported. The commands used to
1726 interface with this new feature are:
1728 compile code [-raw|-r] [--] [source code]
1729 compile file [-raw|-r] filename
1733 demangle [-l language] [--] name
1734 Demangle "name" in the specified language, or the current language
1735 if elided. This command is renamed from the "maint demangle" command.
1736 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1737 as "maint demangler-warning".
1739 queue-signal signal-name-or-number
1740 Queue a signal to be delivered to the thread when it is resumed.
1742 add-auto-load-scripts-directory directory
1743 Add entries to the list of directories from which to load auto-loaded
1746 maint print user-registers
1747 List all currently available "user" registers.
1749 compile code [-r|-raw] [--] [source code]
1750 Compile, inject, and execute in the inferior the executable object
1751 code produced by compiling the provided source code.
1753 compile file [-r|-raw] filename
1754 Compile and inject into the inferior the executable object code
1755 produced by compiling the source code stored in the filename
1758 * On resume, GDB now always passes the signal the program had stopped
1759 for to the thread the signal was sent to, even if the user changed
1760 threads before resuming. Previously GDB would often (but not
1761 always) deliver the signal to the thread that happens to be current
1764 * Conversely, the "signal" command now consistently delivers the
1765 requested signal to the current thread. GDB now asks for
1766 confirmation if the program had stopped for a signal and the user
1767 switched threads meanwhile.
1769 * "breakpoint always-inserted" modes "off" and "auto" merged.
1771 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1772 won't remove breakpoints from the target until all threads stop,
1773 even in non-stop mode. The "auto" mode has been removed, and "off"
1774 is now the default mode.
1778 set debug symbol-lookup
1779 show debug symbol-lookup
1780 Control display of debugging info regarding symbol lookup.
1784 ** The -list-thread-groups command outputs an exit-code field for
1785 inferiors that have exited.
1789 MIPS SDE mips*-sde*-elf*
1793 Support for these obsolete configurations has been removed.
1795 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1796 SGI Irix-5.x mips-*-irix5*
1797 SGI Irix-6.x mips-*-irix6*
1798 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1799 VAX running Ultrix vax-*-ultrix*
1801 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1802 and "assf"), have been removed. Use the "sharedlibrary" command, or
1803 its alias "share", instead.
1805 *** Changes in GDB 7.8
1807 * New command line options
1810 This is an alias for the --data-directory option.
1812 * GDB supports printing and modifying of variable length automatic arrays
1813 as specified in ISO C99.
1815 * The ARM simulator now supports instruction level tracing
1816 with or without disassembly.
1820 GDB now has support for scripting using Guile. Whether this is
1821 available is determined at configure time.
1822 Guile version 2.0 or greater is required.
1823 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1825 * New commands (for set/show, see "New options" below)
1829 Invoke CODE by passing it to the Guile interpreter.
1833 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1835 info auto-load guile-scripts [regexp]
1836 Print the list of automatically loaded Guile scripts.
1838 * The source command is now capable of sourcing Guile scripts.
1839 This feature is dependent on the debugger being built with Guile support.
1843 set print symbol-loading (off|brief|full)
1844 show print symbol-loading
1845 Control whether to print informational messages when loading symbol
1846 information for a file. The default is "full", but when debugging
1847 programs with large numbers of shared libraries the amount of output
1848 becomes less useful.
1850 set guile print-stack (none|message|full)
1851 show guile print-stack
1852 Show a stack trace when an error is encountered in a Guile script.
1854 set auto-load guile-scripts (on|off)
1855 show auto-load guile-scripts
1856 Control auto-loading of Guile script files.
1858 maint ada set ignore-descriptive-types (on|off)
1859 maint ada show ignore-descriptive-types
1860 Control whether the debugger should ignore descriptive types in Ada
1861 programs. The default is not to ignore the descriptive types. See
1862 the user manual for more details on descriptive types and the intended
1863 usage of this option.
1865 set auto-connect-native-target
1867 Control whether GDB is allowed to automatically connect to the
1868 native target for the run, attach, etc. commands when not connected
1869 to any target yet. See also "target native" below.
1871 set record btrace replay-memory-access (read-only|read-write)
1872 show record btrace replay-memory-access
1873 Control what memory accesses are allowed during replay.
1875 maint set target-async (on|off)
1876 maint show target-async
1877 This controls whether GDB targets operate in synchronous or
1878 asynchronous mode. Normally the default is asynchronous, if it is
1879 available; but this can be changed to more easily debug problems
1880 occurring only in synchronous mode.
1882 set mi-async (on|off)
1884 Control whether MI asynchronous mode is preferred. This supersedes
1885 "set target-async" of previous GDB versions.
1887 * "set target-async" is deprecated as a CLI option and is now an alias
1888 for "set mi-async" (only puts MI into async mode).
1890 * Background execution commands (e.g., "c&", "s&", etc.) are now
1891 possible ``out of the box'' if the target supports them. Previously
1892 the user would need to explicitly enable the possibility with the
1893 "set target-async on" command.
1895 * New features in the GDB remote stub, GDBserver
1897 ** New option --debug-format=option1[,option2,...] allows one to add
1898 additional text to each output. At present only timestamps
1899 are supported: --debug-format=timestamps.
1900 Timestamps can also be turned on with the
1901 "monitor set debug-format timestamps" command from GDB.
1903 * The 'record instruction-history' command now starts counting instructions
1904 at one. This also affects the instruction ranges reported by the
1905 'record function-call-history' command when given the /i modifier.
1907 * The command 'record function-call-history' supports a new modifier '/c' to
1908 indent the function names based on their call stack depth.
1909 The fields for the '/i' and '/l' modifier have been reordered.
1910 The source line range is now prefixed with 'at'.
1911 The instruction range is now prefixed with 'inst'.
1912 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1913 "record instruction-history" and "list" commands.
1915 * The ranges given as arguments to the 'record function-call-history' and
1916 'record instruction-history' commands are now inclusive.
1918 * The btrace record target now supports the 'record goto' command.
1919 For locations inside the execution trace, the back trace is computed
1920 based on the information stored in the execution trace.
1922 * The btrace record target supports limited reverse execution and replay.
1923 The target does not record data and therefore does not allow reading
1924 memory or registers.
1926 * The "catch syscall" command now works on s390*-linux* targets.
1928 * The "compare-sections" command is no longer specific to target
1929 remote. It now works with all targets.
1931 * All native targets are now consistently called "native".
1932 Consequently, the "target child", "target GNU", "target djgpp",
1933 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1934 commands have been replaced with "target native". The QNX/NTO port
1935 leaves the "procfs" target in place and adds a "native" target for
1936 consistency with other ports. The impact on users should be minimal
1937 as these commands previously either throwed an error, or were
1938 no-ops. The target's name is visible in the output of the following
1939 commands: "help target", "info target", "info files", "maint print
1942 * The "target native" command now connects to the native target. This
1943 can be used to launch native programs even when "set
1944 auto-connect-native-target" is set to off.
1946 * GDB now supports access to Intel MPX registers on GNU/Linux.
1948 * Support for Intel AVX-512 registers on GNU/Linux.
1949 Support displaying and modifying Intel AVX-512 registers
1950 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1952 * New remote packets
1954 qXfer:btrace:read's annex
1955 The qXfer:btrace:read packet supports a new annex 'delta' to read
1956 branch trace incrementally.
1960 ** Valid Python operations on gdb.Value objects representing
1961 structs/classes invoke the corresponding overloaded operators if
1963 ** New `Xmethods' feature in the Python API. Xmethods are
1964 additional methods or replacements for existing methods of a C++
1965 class. This feature is useful for those cases where a method
1966 defined in C++ source code could be inlined or optimized out by
1967 the compiler, making it unavailable to GDB.
1970 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1972 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1973 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1974 its alias "share", instead.
1976 * The commands "set remotebaud" and "show remotebaud" are no longer
1977 supported. Use "set serial baud" and "show serial baud" (respectively)
1982 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1983 target-async". The latter is left as a deprecated alias of the
1984 former for backward compatibility. If the target supports it,
1985 CLI background execution commands are now always possible by
1986 default, independently of whether the frontend stated a
1987 preference for asynchronous execution with "-gdb-set mi-async".
1988 Previously "-gdb-set target-async off" affected both MI execution
1989 commands and CLI execution commands.
1991 *** Changes in GDB 7.7
1993 * Improved support for process record-replay and reverse debugging on
1994 arm*-linux* targets. Support for thumb32 and syscall instruction
1995 recording has been added.
1997 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1999 * GDB now supports Fission DWP file format version 2.
2000 http://gcc.gnu.org/wiki/DebugFission
2002 * New convenience function "$_isvoid", to check whether an expression
2003 is void. A void expression is an expression where the type of the
2004 result is "void". For example, some convenience variables may be
2005 "void" when evaluated (e.g., "$_exitcode" before the execution of
2006 the program being debugged; or an undefined convenience variable).
2007 Another example, when calling a function whose return type is
2010 * The "maintenance print objfiles" command now takes an optional regexp.
2012 * The "catch syscall" command now works on arm*-linux* targets.
2014 * GDB now consistently shows "<not saved>" when printing values of
2015 registers the debug info indicates have not been saved in the frame
2016 and there's nowhere to retrieve them from
2017 (callee-saved/call-clobbered registers):
2022 (gdb) info registers rax
2025 Before, the former would print "<optimized out>", and the latter
2026 "*value not available*".
2028 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2033 ** Frame filters and frame decorators have been added.
2034 ** Temporary breakpoints are now supported.
2035 ** Line tables representation has been added.
2036 ** New attribute 'parent_type' for gdb.Field objects.
2037 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2038 ** New attribute 'name' for gdb.Type objects.
2042 Nios II ELF nios2*-*-elf
2043 Nios II GNU/Linux nios2*-*-linux
2044 Texas Instruments MSP430 msp430*-*-elf
2046 * Removed native configurations
2048 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2049 been removed. ELF variants of these configurations are kept supported.
2051 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2052 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2053 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2054 i[34567]86-*-openbsd3.[0-3]
2055 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2056 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2057 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2061 Like "catch throw", but catches a re-thrown exception.
2062 maint check-psymtabs
2063 Renamed from old "maint check-symtabs".
2065 Perform consistency checks on symtabs.
2066 maint expand-symtabs
2067 Expand symtabs matching an optional regexp.
2070 Display the details of GDB configure-time options.
2072 maint set|show per-command
2073 maint set|show per-command space
2074 maint set|show per-command time
2075 maint set|show per-command symtab
2076 Enable display of per-command gdb resource usage.
2078 remove-symbol-file FILENAME
2079 remove-symbol-file -a ADDRESS
2080 Remove a symbol file added via add-symbol-file. The file to remove
2081 can be identified by its filename or by an address that lies within
2082 the boundaries of this symbol file in memory.
2085 info exceptions REGEXP
2086 Display the list of Ada exceptions defined in the program being
2087 debugged. If provided, only the exceptions whose names match REGEXP
2092 set debug symfile off|on
2094 Control display of debugging info regarding reading symbol files and
2095 symbol tables within those files
2097 set print raw frame-arguments
2098 show print raw frame-arguments
2099 Set/show whether to print frame arguments in raw mode,
2100 disregarding any defined pretty-printers.
2102 set remote trace-status-packet
2103 show remote trace-status-packet
2104 Set/show the use of remote protocol qTStatus packet.
2108 Control display of debugging messages related to Nios II targets.
2112 Control whether target-assisted range stepping is enabled.
2114 set startup-with-shell
2115 show startup-with-shell
2116 Specifies whether Unix child processes are started via a shell or
2121 Use the target memory cache for accesses to the code segment. This
2122 improves performance of remote debugging (particularly disassembly).
2124 * You can now use a literal value 'unlimited' for options that
2125 interpret 0 or -1 as meaning "unlimited". E.g., "set
2126 trace-buffer-size unlimited" is now an alias for "set
2127 trace-buffer-size -1" and "set height unlimited" is now an alias for
2130 * The "set debug symtab-create" debugging option of GDB has been changed to
2131 accept a verbosity level. 0 means "off", 1 provides basic debugging
2132 output, and values of 2 or greater provides more verbose output.
2134 * New command-line options
2136 Display the details of GDB configure-time options.
2138 * The command 'tsave' can now support new option '-ctf' to save trace
2139 buffer in Common Trace Format.
2141 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2144 * GDB now implements the the C++ 'typeid' operator.
2146 * The new convenience variable $_exception holds the exception being
2147 thrown or caught at an exception-related catchpoint.
2149 * The exception-related catchpoints, like "catch throw", now accept a
2150 regular expression which can be used to filter exceptions by type.
2152 * The new convenience variable $_exitsignal is automatically set to
2153 the terminating signal number when the program being debugged dies
2154 due to an uncaught signal.
2158 ** All MI commands now accept an optional "--language" option.
2159 Support for this feature can be verified by using the "-list-features"
2160 command, which should contain "language-option".
2162 ** The new command -info-gdb-mi-command allows the user to determine
2163 whether a GDB/MI command is supported or not.
2165 ** The "^error" result record returned when trying to execute an undefined
2166 GDB/MI command now provides a variable named "code" whose content is the
2167 "undefined-command" error code. Support for this feature can be verified
2168 by using the "-list-features" command, which should contain
2169 "undefined-command-error-code".
2171 ** The -trace-save MI command can optionally save trace buffer in Common
2174 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2176 ** The command -data-list-register-values now accepts an optional
2177 "--skip-unavailable" option. When used, only the available registers
2180 ** The new command -trace-frame-collected dumps collected variables,
2181 computed expressions, tvars, memory and registers in a traceframe.
2183 ** The commands -stack-list-locals, -stack-list-arguments and
2184 -stack-list-variables now accept an option "--skip-unavailable".
2185 When used, only the available locals or arguments are displayed.
2187 ** The -exec-run command now accepts an optional "--start" option.
2188 When used, the command follows the same semantics as the "start"
2189 command, stopping the program's execution at the start of its
2190 main subprogram. Support for this feature can be verified using
2191 the "-list-features" command, which should contain
2192 "exec-run-start-option".
2194 ** The new commands -catch-assert and -catch-exceptions insert
2195 catchpoints stopping the program when Ada exceptions are raised.
2197 ** The new command -info-ada-exceptions provides the equivalent of
2198 the new "info exceptions" command.
2200 * New system-wide configuration scripts
2201 A GDB installation now provides scripts suitable for use as system-wide
2202 configuration scripts for the following systems:
2206 * GDB now supports target-assigned range stepping with remote targets.
2207 This improves the performance of stepping source lines by reducing
2208 the number of control packets from/to GDB. See "New remote packets"
2211 * GDB now understands the element 'tvar' in the XML traceframe info.
2212 It has the id of the collected trace state variables.
2214 * On S/390 targets that provide the transactional-execution feature,
2215 the program interruption transaction diagnostic block (TDB) is now
2216 represented as a number of additional "registers" in GDB.
2218 * New remote packets
2222 The vCont packet supports a new 'r' action, that tells the remote
2223 stub to step through an address range itself, without GDB
2224 involvemement at each single-step.
2226 qXfer:libraries-svr4:read's annex
2227 The previously unused annex of the qXfer:libraries-svr4:read packet
2228 is now used to support passing an argument list. The remote stub
2229 reports support for this argument list to GDB's qSupported query.
2230 The defined arguments are "start" and "prev", used to reduce work
2231 necessary for library list updating, resulting in significant
2234 * New features in the GDB remote stub, GDBserver
2236 ** GDBserver now supports target-assisted range stepping. Currently
2237 enabled on x86/x86_64 GNU/Linux targets.
2239 ** GDBserver now adds element 'tvar' in the XML in the reply to
2240 'qXfer:traceframe-info:read'. It has the id of the collected
2241 trace state variables.
2243 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2246 * New 'z' formatter for printing and examining memory, this displays the
2247 value as hexadecimal zero padded on the left to the size of the type.
2249 * GDB can now use Windows x64 unwinding data.
2251 * The "set remotebaud" command has been replaced by "set serial baud".
2252 Similarly, "show remotebaud" has been replaced by "show serial baud".
2253 The "set remotebaud" and "show remotebaud" commands are still available
2254 to provide backward compatibility with older versions of GDB.
2256 *** Changes in GDB 7.6
2258 * Target record has been renamed to record-full.
2259 Record/replay is now enabled with the "record full" command.
2260 This also affects settings that are associated with full record/replay
2261 that have been moved from "set/show record" to "set/show record full":
2263 set|show record full insn-number-max
2264 set|show record full stop-at-limit
2265 set|show record full memory-query
2267 * A new record target "record-btrace" has been added. The new target
2268 uses hardware support to record the control-flow of a process. It
2269 does not support replaying the execution, but it implements the
2270 below new commands for investigating the recorded execution log.
2271 This new recording method can be enabled using:
2275 The "record-btrace" target is only available on Intel Atom processors
2276 and requires a Linux kernel 2.6.32 or later.
2278 * Two new commands have been added for record/replay to give information
2279 about the recorded execution without having to replay the execution.
2280 The commands are only supported by "record btrace".
2282 record instruction-history prints the execution history at
2283 instruction granularity
2285 record function-call-history prints the execution history at
2286 function granularity
2288 * New native configurations
2290 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2291 FreeBSD/powerpc powerpc*-*-freebsd
2292 x86_64/Cygwin x86_64-*-cygwin*
2293 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2297 ARM AArch64 aarch64*-*-elf
2298 ARM AArch64 GNU/Linux aarch64*-*-linux
2299 Lynx 178 PowerPC powerpc-*-lynx*178
2300 x86_64/Cygwin x86_64-*-cygwin*
2301 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2303 * If the configured location of system.gdbinit file (as given by the
2304 --with-system-gdbinit option at configure time) is in the
2305 data-directory (as specified by --with-gdb-datadir at configure
2306 time) or in one of its subdirectories, then GDB will look for the
2307 system-wide init file in the directory specified by the
2308 --data-directory command-line option.
2310 * New command line options:
2312 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2313 other initialization files, unlike -nx which disables all of them.
2315 * Removed command line options
2317 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2320 * The 'ptype' and 'whatis' commands now accept an argument to control
2323 * 'info proc' now works on some core files.
2327 ** Vectors can be created with gdb.Type.vector.
2329 ** Python's atexit.register now works in GDB.
2331 ** Types can be pretty-printed via a Python API.
2333 ** Python 3 is now supported (in addition to Python 2.4 or later)
2335 ** New class gdb.Architecture exposes GDB's internal representation
2336 of architecture in the Python API.
2338 ** New method Frame.architecture returns the gdb.Architecture object
2339 corresponding to the frame's architecture.
2341 * New Python-based convenience functions:
2343 ** $_memeq(buf1, buf2, length)
2344 ** $_streq(str1, str2)
2346 ** $_regex(str, regex)
2348 * The 'cd' command now defaults to using '~' (the home directory) if not
2351 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2352 default for GCC since November 2000.
2354 * The command 'forward-search' can now be abbreviated as 'fo'.
2356 * The command 'info tracepoints' can now display 'installed on target'
2357 or 'not installed on target' for each non-pending location of tracepoint.
2359 * New configure options
2361 --enable-libmcheck/--disable-libmcheck
2362 By default, development versions are built with -lmcheck on hosts
2363 that support it, in order to help track memory corruption issues.
2364 Release versions, on the other hand, are built without -lmcheck
2365 by default. The --enable-libmcheck/--disable-libmcheck configure
2366 options allow the user to override that default.
2367 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2368 This configure option allows the user to build GDB with
2369 libbabeltrace using which GDB can read Common Trace Format data.
2371 * New commands (for set/show, see "New options" below)
2374 Catch signals. This is similar to "handle", but allows commands and
2375 conditions to be attached.
2378 List the BFDs known to GDB.
2380 python-interactive [command]
2382 Start a Python interactive prompt, or evaluate the optional command
2383 and print the result of expressions.
2386 "py" is a new alias for "python".
2388 enable type-printer [name]...
2389 disable type-printer [name]...
2390 Enable or disable type printers.
2394 ** For the Renesas Super-H architecture, the "regs" command has been removed
2395 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2400 set print type methods (on|off)
2401 show print type methods
2402 Control whether method declarations are displayed by "ptype".
2403 The default is to show them.
2405 set print type typedefs (on|off)
2406 show print type typedefs
2407 Control whether typedef definitions are displayed by "ptype".
2408 The default is to show them.
2410 set filename-display basename|relative|absolute
2411 show filename-display
2412 Control the way in which filenames is displayed.
2413 The default is "relative", which preserves previous behavior.
2415 set trace-buffer-size
2416 show trace-buffer-size
2417 Request target to change the size of trace buffer.
2419 set remote trace-buffer-size-packet auto|on|off
2420 show remote trace-buffer-size-packet
2421 Control the use of the remote protocol `QTBuffer:size' packet.
2425 Control display of debugging messages related to ARM AArch64.
2428 set debug coff-pe-read
2429 show debug coff-pe-read
2430 Control display of debugging messages related to reading of COFF/PE
2435 Control display of debugging messages related to Mach-O symbols
2438 set debug notification
2439 show debug notification
2440 Control display of debugging info for async remote notification.
2444 ** Command parameter changes are now notified using new async record
2445 "=cmd-param-changed".
2446 ** Trace frame changes caused by command "tfind" are now notified using
2447 new async record "=traceframe-changed".
2448 ** The creation, deletion and modification of trace state variables
2449 are now notified using new async records "=tsv-created",
2450 "=tsv-deleted" and "=tsv-modified".
2451 ** The start and stop of process record are now notified using new
2452 async record "=record-started" and "=record-stopped".
2453 ** Memory changes are now notified using new async record
2455 ** The data-disassemble command response will include a "fullname" field
2456 containing the absolute file name when source has been requested.
2457 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2458 command, to allow pattern filling of memory areas.
2459 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2460 library load/unload events.
2461 ** The response to breakpoint commands and breakpoint async records
2462 includes an "installed" field containing a boolean state about each
2463 non-pending tracepoint location is whether installed on target or not.
2464 ** Output of the "-trace-status" command includes a "trace-file" field
2465 containing the name of the trace file being examined. This field is
2466 optional, and only present when examining a trace file.
2467 ** The "fullname" field is now always present along with the "file" field,
2468 even if the file cannot be found by GDB.
2470 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2471 You must have the LZMA library available when configuring GDB for this
2472 feature to be enabled. For more information, see:
2473 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2475 * New remote packets
2478 Set the size of trace buffer. The remote stub reports support for this
2479 packet to gdb's qSupported query.
2482 Enable Branch Trace Store (BTS)-based branch tracing for the current
2483 thread. The remote stub reports support for this packet to gdb's
2487 Disable branch tracing for the current thread. The remote stub reports
2488 support for this packet to gdb's qSupported query.
2491 Read the traced branches for the current thread. The remote stub
2492 reports support for this packet to gdb's qSupported query.
2494 *** Changes in GDB 7.5
2496 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2497 for more x32 ABI info.
2499 * GDB now supports access to MIPS DSP registers on Linux targets.
2501 * GDB now supports debugging microMIPS binaries.
2503 * The "info os" command on GNU/Linux can now display information on
2504 several new classes of objects managed by the operating system:
2505 "info os procgroups" lists process groups
2506 "info os files" lists file descriptors
2507 "info os sockets" lists internet-domain sockets
2508 "info os shm" lists shared-memory regions
2509 "info os semaphores" lists semaphores
2510 "info os msg" lists message queues
2511 "info os modules" lists loaded kernel modules
2513 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2514 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2515 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2516 options and inspect the probe arguments using the new $_probe_arg family
2517 of convenience variables. You can obtain more information about SystemTap
2518 in <http://sourceware.org/systemtap/>.
2520 * GDB now supports reversible debugging on ARM, it allows you to
2521 debug basic ARM and THUMB instructions, and provides
2522 record/replay support.
2524 * The option "symbol-reloading" has been deleted as it is no longer used.
2528 ** GDB commands implemented in Python can now be put in command class
2531 ** The "maint set python print-stack on|off" is now deleted.
2533 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2534 apply "flag enum"-style pretty-printing to any enum.
2536 ** gdb.lookup_symbol can now work when there is no current frame.
2538 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2539 the source at which the symbol was defined.
2541 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2542 method 'value'. The former indicates whether the symbol needs a
2543 frame in order to compute its value, and the latter computes the
2546 ** A new method 'referenced_value' on gdb.Value objects which can
2547 dereference pointer as well as C++ reference values.
2549 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2550 which return the global and static blocks (as gdb.Block objects),
2551 of the underlying symbol table, respectively.
2553 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2554 object associated with a PC value.
2556 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2557 of the address range occupied by code for the current source line.
2559 * Go language support.
2560 GDB now supports debugging programs written in the Go programming
2563 * GDBserver now supports stdio connections.
2564 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2566 * The binary "gdbtui" can no longer be built or installed.
2567 Use "gdb -tui" instead.
2569 * GDB will now print "flag" enums specially. A flag enum is one where
2570 all the enumerator values have no bits in common when pairwise
2571 "and"ed. When printing a value whose type is a flag enum, GDB will
2572 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2573 (gdb) print (enum E) 3
2576 * The filename part of a linespec will now match trailing components
2577 of a source file name. For example, "break gcc/expr.c:1000" will
2578 now set a breakpoint in build/gcc/expr.c, but not
2579 build/libcpp/expr.c.
2581 * The "info proc" and "generate-core-file" commands will now also
2582 work on remote targets connected to GDBserver on Linux.
2584 * The command "info catch" has been removed. It has been disabled
2585 since December 2007.
2587 * The "catch exception" and "catch assert" commands now accept
2588 a condition at the end of the command, much like the "break"
2589 command does. For instance:
2591 (gdb) catch exception Constraint_Error if Barrier = True
2593 Previously, it was possible to add a condition to such catchpoints,
2594 but it had to be done as a second step, after the catchpoint had been
2595 created, using the "condition" command.
2597 * The "info static-tracepoint-marker" command will now also work on
2598 native Linux targets with in-process agent.
2600 * GDB can now set breakpoints on inlined functions.
2602 * The .gdb_index section has been updated to include symbols for
2603 inlined functions. GDB will ignore older .gdb_index sections by
2604 default, which could cause symbol files to be loaded more slowly
2605 until their .gdb_index sections can be recreated. The new command
2606 "set use-deprecated-index-sections on" will cause GDB to use any older
2607 .gdb_index sections it finds. This will restore performance, but the
2608 ability to set breakpoints on inlined functions will be lost in symbol
2609 files with older .gdb_index sections.
2611 The .gdb_index section has also been updated to record more information
2612 about each symbol. This speeds up the "info variables", "info functions"
2613 and "info types" commands when used with programs having the .gdb_index
2614 section, as well as speeding up debugging with shared libraries using
2615 the .gdb_index section.
2617 * Ada support for GDB/MI Variable Objects has been added.
2619 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2624 ** New command -info-os is the MI equivalent of "info os".
2626 ** Output logs ("set logging" and related) now include MI output.
2630 ** "set use-deprecated-index-sections on|off"
2631 "show use-deprecated-index-sections on|off"
2632 Controls the use of deprecated .gdb_index sections.
2634 ** "catch load" and "catch unload" can be used to stop when a shared
2635 library is loaded or unloaded, respectively.
2637 ** "enable count" can be used to auto-disable a breakpoint after
2640 ** "info vtbl" can be used to show the virtual method tables for
2641 C++ and Java objects.
2643 ** "explore" and its sub commands "explore value" and "explore type"
2644 can be used to recursively explore values and types of
2645 expressions. These commands are available only if GDB is
2646 configured with '--with-python'.
2648 ** "info auto-load" shows status of all kinds of auto-loaded files,
2649 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2650 sequences of commands files, "info auto-load python-scripts"
2651 shows status of auto-loading Python script files,
2652 "info auto-load local-gdbinit" shows status of loading init file
2653 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2654 status of inferior specific thread debugging shared library loading.
2656 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2657 and "show auto-load-scripts" commands have been deprecated, use their
2658 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2659 and "show auto-load python-scripts" counterparts instead.
2661 ** "dprintf location,format,args..." creates a dynamic printf, which
2662 is basically a breakpoint that does a printf and immediately
2663 resumes your program's execution, so it is like a printf that you
2664 can insert dynamically at runtime instead of at compiletime.
2666 ** "set print symbol"
2668 Controls whether GDB attempts to display the symbol, if any,
2669 corresponding to addresses it prints. This defaults to "on", but
2670 you can set it to "off" to restore GDB's previous behavior.
2672 * Deprecated commands
2674 ** For the Renesas Super-H architecture, the "regs" command has been
2675 deprecated, and "info all-registers" should be used instead.
2679 Renesas RL78 rl78-*-elf
2680 HP OpenVMS ia64 ia64-hp-openvms*
2682 * GDBserver supports evaluation of breakpoint conditions. When
2683 support is advertised by GDBserver, GDB may be told to send the
2684 breakpoint conditions in bytecode form to GDBserver. GDBserver
2685 will only report the breakpoint trigger to GDB when its condition
2690 set mips compression
2691 show mips compression
2692 Select the compressed ISA encoding used in functions that have no symbol
2693 information available. The encoding can be set to either of:
2696 and is updated automatically from ELF file flags if available.
2698 set breakpoint condition-evaluation
2699 show breakpoint condition-evaluation
2700 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2701 GDBserver ("target"). Default option "auto" chooses the most efficient
2703 This option can improve debugger efficiency depending on the speed of the
2707 Disable auto-loading globally.
2710 Show auto-loading setting of all kinds of auto-loaded files.
2712 set auto-load gdb-scripts on|off
2713 show auto-load gdb-scripts
2714 Control auto-loading of GDB canned sequences of commands files.
2716 set auto-load python-scripts on|off
2717 show auto-load python-scripts
2718 Control auto-loading of Python script files.
2720 set auto-load local-gdbinit on|off
2721 show auto-load local-gdbinit
2722 Control loading of init file (.gdbinit) from current directory.
2724 set auto-load libthread-db on|off
2725 show auto-load libthread-db
2726 Control auto-loading of inferior specific thread debugging shared library.
2728 set auto-load scripts-directory <dir1>[:<dir2>...]
2729 show auto-load scripts-directory
2730 Set a list of directories from which to load auto-loaded scripts.
2731 Automatically loaded Python scripts and GDB scripts are located in one
2732 of the directories listed by this option.
2733 The delimiter (':' above) may differ according to the host platform.
2735 set auto-load safe-path <dir1>[:<dir2>...]
2736 show auto-load safe-path
2737 Set a list of directories from which it is safe to auto-load files.
2738 The delimiter (':' above) may differ according to the host platform.
2740 set debug auto-load on|off
2741 show debug auto-load
2742 Control display of debugging info for auto-loading the files above.
2744 set dprintf-style gdb|call|agent
2746 Control the way in which a dynamic printf is performed; "gdb"
2747 requests a GDB printf command, while "call" causes dprintf to call a
2748 function in the inferior. "agent" requests that the target agent
2749 (such as GDBserver) do the printing.
2751 set dprintf-function <expr>
2752 show dprintf-function
2753 set dprintf-channel <expr>
2754 show dprintf-channel
2755 Set the function and optional first argument to the call when using
2756 the "call" style of dynamic printf.
2758 set disconnected-dprintf on|off
2759 show disconnected-dprintf
2760 Control whether agent-style dynamic printfs continue to be in effect
2761 after GDB disconnects.
2763 * New configure options
2765 --with-auto-load-dir
2766 Configure default value for the 'set auto-load scripts-directory'
2767 setting above. It defaults to '$debugdir:$datadir/auto-load',
2768 $debugdir representing global debugging info directories (available
2769 via 'show debug-file-directory') and $datadir representing GDB's data
2770 directory (available via 'show data-directory').
2772 --with-auto-load-safe-path
2773 Configure default value for the 'set auto-load safe-path' setting
2774 above. It defaults to the --with-auto-load-dir setting.
2776 --without-auto-load-safe-path
2777 Set 'set auto-load safe-path' to '/', effectively disabling this
2780 * New remote packets
2782 z0/z1 conditional breakpoints extension
2784 The z0/z1 breakpoint insertion packets have been extended to carry
2785 a list of conditional expressions over to the remote stub depending on the
2786 condition evaluation mode. The use of this extension can be controlled
2787 via the "set remote conditional-breakpoints-packet" command.
2791 Specify the signals which the remote stub may pass to the debugged
2792 program without GDB involvement.
2794 * New command line options
2796 --init-command=FILE, -ix Like --command, -x but execute it
2797 before loading inferior.
2798 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2799 execute it before loading inferior.
2801 *** Changes in GDB 7.4
2803 * GDB now handles ambiguous linespecs more consistently; the existing
2804 FILE:LINE support has been expanded to other types of linespecs. A
2805 breakpoint will now be set on all matching locations in all
2806 inferiors, and locations will be added or removed according to
2809 * GDB now allows you to skip uninteresting functions and files when
2810 stepping with the "skip function" and "skip file" commands.
2812 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2813 and "show remote hardware-watchpoint-length-limit". These allows to
2814 set or show the maximum length limit (in bytes) of a remote
2815 target hardware watchpoint.
2817 This allows e.g. to use "unlimited" hardware watchpoints with the
2818 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2819 watchpoints are slower than real hardware watchpoints but are
2820 significantly faster than gdb software watchpoints.
2824 ** The register_pretty_printer function in module gdb.printing now takes
2825 an optional `replace' argument. If True, the new printer replaces any
2828 ** The "maint set python print-stack on|off" command has been
2829 deprecated and will be deleted in GDB 7.5.
2830 A new command: "set python print-stack none|full|message" has
2831 replaced it. Additionally, the default for "print-stack" is
2832 now "message", which just prints the error message without
2835 ** A prompt substitution hook (prompt_hook) is now available to the
2838 ** A new Python module, gdb.prompt has been added to the GDB Python
2839 modules library. This module provides functionality for
2840 escape sequences in prompts (used by set/show
2841 extended-prompt). These escape sequences are replaced by their
2842 corresponding value.
2844 ** Python commands and convenience-functions located in
2845 'data-directory'/python/gdb/command and
2846 'data-directory'/python/gdb/function are now automatically loaded
2849 ** Blocks now provide four new attributes. global_block and
2850 static_block will return the global and static blocks
2851 respectively. is_static and is_global are boolean attributes
2852 that indicate if the block is one of those two types.
2854 ** Symbols now provide the "type" attribute, the type of the symbol.
2856 ** The "gdb.breakpoint" function has been deprecated in favor of
2859 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2860 of a function. This class is based on the "finish" command
2861 available in the CLI.
2863 ** Type objects for struct and union types now allow access to
2864 the fields using standard Python dictionary (mapping) methods.
2865 For example, "some_type['myfield']" now works, as does
2866 "some_type.items()".
2868 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2871 ** A new function, "deep_items" has been added to the gdb.types
2872 module in the GDB Python modules library. This function returns
2873 an iterator over the fields of a struct or union type. Unlike
2874 the standard Python "iteritems" method, it will recursively traverse
2875 any anonymous fields.
2879 ** "*stopped" events can report several new "reason"s, such as
2882 ** Breakpoint changes are now notified using new async records, like
2883 "=breakpoint-modified".
2885 ** New command -ada-task-info.
2887 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2888 $sdir specifies the default system locations of shared libraries.
2889 $pdir specifies the directory where the libpthread used by the application
2892 GDB no longer looks in $sdir and $pdir after it has searched the directories
2893 mentioned in libthread-db-search-path. If you want to search those
2894 directories, they must be specified in libthread-db-search-path.
2895 The default value of libthread-db-search-path on GNU/Linux and Solaris
2896 systems is now "$sdir:$pdir".
2898 $pdir is not supported by gdbserver, it is currently ignored.
2899 $sdir is supported by gdbserver.
2901 * New configure option --with-iconv-bin.
2902 When using the internationalization support like the one in the GNU C
2903 library, GDB will invoke the "iconv" program to get a list of supported
2904 character sets. If this program lives in a non-standard location, one can
2905 use this option to specify where to find it.
2907 * When natively debugging programs on PowerPC BookE processors running
2908 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2909 watchpoints, which specify a mask in addition to an address to watch.
2910 The mask specifies that some bits of an address (the bits which are
2911 reset in the mask) should be ignored when matching the address accessed
2912 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2913 section in the user manual for more details.
2915 * The new option --once causes GDBserver to stop listening for connections once
2916 the first connection is made. The listening port used by GDBserver will
2917 become available after that.
2919 * New commands "info macros" and "alias" have been added.
2921 * New function parameters suffix @entry specifies value of function parameter
2922 at the time the function got called. Entry values are available only since
2928 "!" is now an alias of the "shell" command.
2929 Note that no space is needed between "!" and SHELL COMMAND.
2933 watch EXPRESSION mask MASK_VALUE
2934 The watch command now supports the mask argument which allows creation
2935 of masked watchpoints, if the current architecture supports this feature.
2937 info auto-load-scripts [REGEXP]
2938 This command was formerly named "maintenance print section-scripts".
2939 It is now generally useful and is no longer a maintenance-only command.
2941 info macro [-all] [--] MACRO
2942 The info macro command has new options `-all' and `--'. The first for
2943 printing all definitions of a macro. The second for explicitly specifying
2944 the end of arguments and the beginning of the macro name in case the macro
2945 name starts with a hyphen.
2947 collect[/s] EXPRESSIONS
2948 The tracepoint collect command now takes an optional modifier "/s"
2949 that directs it to dereference pointer-to-character types and
2950 collect the bytes of memory up to a zero byte. The behavior is
2951 similar to what you see when you use the regular print command on a
2952 string. An optional integer following the "/s" sets a bound on the
2953 number of bytes that will be collected.
2956 The trace start command now interprets any supplied arguments as a
2957 note to be recorded with the trace run, with an effect similar to
2958 setting the variable trace-notes.
2961 The trace stop command now interprets any arguments as a note to be
2962 mentioned along with the tstatus report that the trace was stopped
2963 with a command. The effect is similar to setting the variable
2966 * Tracepoints can now be enabled and disabled at any time after a trace
2967 experiment has been started using the standard "enable" and "disable"
2968 commands. It is now possible to start a trace experiment with no enabled
2969 tracepoints; GDB will display a warning, but will allow the experiment to
2970 begin, assuming that tracepoints will be enabled as needed while the trace
2973 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2974 locations with 4-byte instructions, when they were previously
2975 limited to locations with instructions of 5 bytes or longer.
2979 set debug dwarf2-read
2980 show debug dwarf2-read
2981 Turns on or off display of debugging messages related to reading
2982 DWARF debug info. The default is off.
2984 set debug symtab-create
2985 show debug symtab-create
2986 Turns on or off display of debugging messages related to symbol table
2987 creation. The default is off.
2990 show extended-prompt
2991 Set the GDB prompt, and allow escape sequences to be inserted to
2992 display miscellaneous information (see 'help set extended-prompt'
2993 for the list of sequences). This prompt (and any information
2994 accessed through the escape sequences) is updated every time the
2995 prompt is displayed.
2997 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2998 show print entry-values
2999 Set printing of frame argument values at function entry. In some cases
3000 GDB can determine the value of function argument which was passed by the
3001 function caller, even if the value was modified inside the called function.
3003 set debug entry-values
3004 show debug entry-values
3005 Control display of debugging info for determining frame argument values at
3006 function entry and virtual tail call frames.
3008 set basenames-may-differ
3009 show basenames-may-differ
3010 Set whether a source file may have multiple base names.
3011 (A "base name" is the name of a file with the directory part removed.
3012 Example: The base name of "/home/user/hello.c" is "hello.c".)
3013 If set, GDB will canonicalize file names (e.g., expand symlinks)
3014 before comparing them. Canonicalization is an expensive operation,
3015 but it allows the same file be known by more than one base name.
3016 If not set (the default), all source files are assumed to have just
3017 one base name, and gdb will do file name comparisons more efficiently.
3023 Set a user name and notes for the current and any future trace runs.
3024 This is useful for long-running and/or disconnected traces, to
3025 inform others (or yourself) as to who is running the trace, supply
3026 contact information, or otherwise explain what is going on.
3028 set trace-stop-notes
3029 show trace-stop-notes
3030 Set a note attached to the trace run, that is displayed when the
3031 trace has been stopped by a tstop command. This is useful for
3032 instance as an explanation, if you are stopping a trace run that was
3033 started by someone else.
3035 * New remote packets
3039 Dynamically enable a tracepoint in a started trace experiment.
3043 Dynamically disable a tracepoint in a started trace experiment.
3047 Set the user and notes of the trace run.
3051 Query the current status of a tracepoint.
3055 Query the minimum length of instruction at which a fast tracepoint may
3058 * Dcache size (number of lines) and line-size are now runtime-configurable
3059 via "set dcache line" and "set dcache line-size" commands.
3063 Texas Instruments TMS320C6x tic6x-*-*
3067 Renesas RL78 rl78-*-elf
3069 *** Changes in GDB 7.3.1
3071 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3073 *** Changes in GDB 7.3
3075 * GDB has a new command: "thread find [REGEXP]".
3076 It finds the thread id whose name, target id, or thread extra info
3077 matches the given regular expression.
3079 * The "catch syscall" command now works on mips*-linux* targets.
3081 * The -data-disassemble MI command now supports modes 2 and 3 for
3082 dumping the instruction opcodes.
3084 * New command line options
3086 -data-directory DIR Specify DIR as the "data-directory".
3087 This is mostly for testing purposes.
3089 * The "maint set python auto-load on|off" command has been renamed to
3090 "set auto-load-scripts on|off".
3092 * GDB has a new command: "set directories".
3093 It is like the "dir" command except that it replaces the
3094 source path list instead of augmenting it.
3096 * GDB now understands thread names.
3098 On GNU/Linux, "info threads" will display the thread name as set by
3099 prctl or pthread_setname_np.
3101 There is also a new command, "thread name", which can be used to
3102 assign a name internally for GDB to display.
3105 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3106 has been integrated into GDB.
3110 ** The function gdb.Write now accepts an optional keyword 'stream'.
3111 This keyword, when provided, will direct the output to either
3112 stdout, stderr, or GDB's logging output.
3114 ** Parameters can now be be sub-classed in Python, and in particular
3115 you may implement the get_set_doc and get_show_doc functions.
3116 This improves how Parameter set/show documentation is processed
3117 and allows for more dynamic content.
3119 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3120 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3121 have an is_valid method.
3123 ** Breakpoints can now be sub-classed in Python, and in particular
3124 you may implement a 'stop' function that is executed each time
3125 the inferior reaches that breakpoint.
3127 ** New function gdb.lookup_global_symbol looks up a global symbol.
3129 ** GDB values in Python are now callable if the value represents a
3130 function. For example, if 'some_value' represents a function that
3131 takes two integer parameters and returns a value, you can call
3132 that function like so:
3134 result = some_value (10,20)
3136 ** Module gdb.types has been added.
3137 It contains a collection of utilities for working with gdb.Types objects:
3138 get_basic_type, has_field, make_enum_dict.
3140 ** Module gdb.printing has been added.
3141 It contains utilities for writing and registering pretty-printers.
3142 New classes: PrettyPrinter, SubPrettyPrinter,
3143 RegexpCollectionPrettyPrinter.
3144 New function: register_pretty_printer.
3146 ** New commands "info pretty-printers", "enable pretty-printer" and
3147 "disable pretty-printer" have been added.
3149 ** gdb.parameter("directories") is now available.
3151 ** New function gdb.newest_frame returns the newest frame in the
3154 ** The gdb.InferiorThread class has a new "name" attribute. This
3155 holds the thread's name.
3157 ** Python Support for Inferior events.
3158 Python scripts can add observers to be notified of events
3159 occurring in the process being debugged.
3160 The following events are currently supported:
3161 - gdb.events.cont Continue event.
3162 - gdb.events.exited Inferior exited event.
3163 - gdb.events.stop Signal received, and Breakpoint hit events.
3167 ** GDB now puts template parameters in scope when debugging in an
3168 instantiation. For example, if you have:
3170 template<int X> int func (void) { return X; }
3172 then if you step into func<5>, "print X" will show "5". This
3173 feature requires proper debuginfo support from the compiler; it
3174 was added to GCC 4.5.
3176 ** The motion commands "next", "finish", "until", and "advance" now
3177 work better when exceptions are thrown. In particular, GDB will
3178 no longer lose control of the inferior; instead, the GDB will
3179 stop the inferior at the point at which the exception is caught.
3180 This functionality requires a change in the exception handling
3181 code that was introduced in GCC 4.5.
3183 * GDB now follows GCC's rules on accessing volatile objects when
3184 reading or writing target state during expression evaluation.
3185 One notable difference to prior behavior is that "print x = 0"
3186 no longer generates a read of x; the value of the assignment is
3187 now always taken directly from the value being assigned.
3189 * GDB now has some support for using labels in the program's source in
3190 linespecs. For instance, you can use "advance label" to continue
3191 execution to a label.
3193 * GDB now has support for reading and writing a new .gdb_index
3194 section. This section holds a fast index of DWARF debugging
3195 information and can be used to greatly speed up GDB startup and
3196 operation. See the documentation for `save gdb-index' for details.
3198 * The "watch" command now accepts an optional "-location" argument.
3199 When used, this causes GDB to watch the memory referred to by the
3200 expression. Such a watchpoint is never deleted due to it going out
3203 * GDB now supports thread debugging of core dumps on GNU/Linux.
3205 GDB now activates thread debugging using the libthread_db library
3206 when debugging GNU/Linux core dumps, similarly to when debugging
3207 live processes. As a result, when debugging a core dump file, GDB
3208 is now able to display pthread_t ids of threads. For example, "info
3209 threads" shows the same output as when debugging the process when it
3210 was live. In earlier releases, you'd see something like this:
3213 * 1 LWP 6780 main () at main.c:10
3215 While now you see this:
3218 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3220 It is also now possible to inspect TLS variables when debugging core
3223 When debugging a core dump generated on a machine other than the one
3224 used to run GDB, you may need to point GDB at the correct
3225 libthread_db library with the "set libthread-db-search-path"
3226 command. See the user manual for more details on this command.
3228 * When natively debugging programs on PowerPC BookE processors running
3229 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3230 which stop execution of the inferior whenever it executes an instruction
3231 at any address within the specified range. See the "PowerPC Embedded"
3232 section in the user manual for more details.
3234 * New features in the GDB remote stub, GDBserver
3236 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3237 and i686 LynxOS (version 5.x).
3239 ** GDBserver is now supported on Blackfin Linux.
3241 * New native configurations
3243 ia64 HP-UX ia64-*-hpux*
3247 Analog Devices, Inc. Blackfin Processor bfin-*
3249 * Ada task switching is now supported on sparc-elf targets when
3250 debugging a program using the Ravenscar Profile. For more information,
3251 see the "Tasking Support when using the Ravenscar Profile" section
3252 in the GDB user manual.
3254 * Guile support was removed.
3256 * New features in the GNU simulator
3258 ** The --map-info flag lists all known core mappings.
3260 ** CFI flashes may be simulated via the "cfi" device.
3262 *** Changes in GDB 7.2
3264 * Shared library support for remote targets by default
3266 When GDB is configured for a generic, non-OS specific target, like
3267 for example, --target=arm-eabi or one of the many *-*-elf targets,
3268 GDB now queries remote stubs for loaded shared libraries using the
3269 `qXfer:libraries:read' packet. Previously, shared library support
3270 was always disabled for such configurations.
3274 ** Argument Dependent Lookup (ADL)
3276 In C++ ADL lookup directs function search to the namespaces of its
3277 arguments even if the namespace has not been imported.
3287 Here the compiler will search for `foo' in the namespace of 'b'
3288 and find A::foo. GDB now supports this. This construct is commonly
3289 used in the Standard Template Library for operators.
3291 ** Improved User Defined Operator Support
3293 In addition to member operators, GDB now supports lookup of operators
3294 defined in a namespace and imported with a `using' directive, operators
3295 defined in the global scope, operators imported implicitly from an
3296 anonymous namespace, and the ADL operators mentioned in the previous
3298 GDB now also supports proper overload resolution for all the previously
3299 mentioned flavors of operators.
3301 ** static const class members
3303 Printing of static const class members that are initialized in the
3304 class definition has been fixed.
3306 * Windows Thread Information Block access.
3308 On Windows targets, GDB now supports displaying the Windows Thread
3309 Information Block (TIB) structure. This structure is visible either
3310 by using the new command `info w32 thread-information-block' or, by
3311 dereferencing the new convenience variable named `$_tlb', a
3312 thread-specific pointer to the TIB. This feature is also supported
3313 when remote debugging using GDBserver.
3315 * Static tracepoints
3317 Static tracepoints are calls in the user program into a tracing
3318 library. One such library is a port of the LTTng kernel tracer to
3319 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3320 When debugging with GDBserver, GDB now supports combining the GDB
3321 tracepoint machinery with such libraries. For example: the user can
3322 use GDB to probe a static tracepoint marker (a call from the user
3323 program into the tracing library) with the new "strace" command (see
3324 "New commands" below). This creates a "static tracepoint" in the
3325 breakpoint list, that can be manipulated with the same feature set
3326 as fast and regular tracepoints. E.g., collect registers, local and
3327 global variables, collect trace state variables, and define
3328 tracepoint conditions. In addition, the user can collect extra
3329 static tracepoint marker specific data, by collecting the new
3330 $_sdata internal variable. When analyzing the trace buffer, you can
3331 inspect $_sdata like any other variable available to GDB. For more
3332 information, see the "Tracepoints" chapter in GDB user manual. New
3333 remote packets have been defined to support static tracepoints, see
3334 the "New remote packets" section below.
3336 * Better reconstruction of tracepoints after disconnected tracing
3338 GDB will attempt to download the original source form of tracepoint
3339 definitions when starting a trace run, and then will upload these
3340 upon reconnection to the target, resulting in a more accurate
3341 reconstruction of the tracepoints that are in use on the target.
3345 You can now exercise direct control over the ways that GDB can
3346 affect your program. For instance, you can disallow the setting of
3347 breakpoints, so that the program can run continuously (assuming
3348 non-stop mode). In addition, the "observer" variable is available
3349 to switch all of the different controls; in observer mode, GDB
3350 cannot affect the target's behavior at all, which is useful for
3351 tasks like diagnosing live systems in the field.
3353 * The new convenience variable $_thread holds the number of the
3356 * New remote packets
3360 Return the address of the Windows Thread Information Block of a given thread.
3364 In response to several of the tracepoint packets, the target may now
3365 also respond with a number of intermediate `qRelocInsn' request
3366 packets before the final result packet, to have GDB handle
3367 relocating an instruction to execute at a different address. This
3368 is particularly useful for stubs that support fast tracepoints. GDB
3369 reports support for this feature in the qSupported packet.
3373 List static tracepoint markers in the target program.
3377 List static tracepoint markers at a given address in the target
3380 qXfer:statictrace:read
3382 Read the static trace data collected (by a `collect $_sdata'
3383 tracepoint action). The remote stub reports support for this packet
3384 to gdb's qSupported query.
3388 Send the current settings of GDB's permission flags.
3392 Send part of the source (textual) form of a tracepoint definition,
3393 which includes location, conditional, and action list.
3395 * The source command now accepts a -s option to force searching for the
3396 script in the source search path even if the script name specifies
3399 * New features in the GDB remote stub, GDBserver
3401 - GDBserver now support tracepoints (including fast tracepoints, and
3402 static tracepoints). The feature is currently supported by the
3403 i386-linux and amd64-linux builds. See the "Tracepoints support
3404 in gdbserver" section in the manual for more information.
3406 GDBserver JIT compiles the tracepoint's conditional agent
3407 expression bytecode into native code whenever possible for low
3408 overhead dynamic tracepoints conditionals. For such tracepoints,
3409 an expression that examines program state is evaluated when the
3410 tracepoint is reached, in order to determine whether to capture
3411 trace data. If the condition is simple and false, processing the
3412 tracepoint finishes very quickly and no data is gathered.
3414 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3415 for static tracepoints support.
3417 - GDBserver now supports x86_64 Windows 64-bit debugging.
3419 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3420 it understands register description.
3422 * The --batch flag now disables pagination and queries.
3424 * X86 general purpose registers
3426 GDB now supports reading/writing byte, word and double-word x86
3427 general purpose registers directly. This means you can use, say,
3428 $ah or $ax to refer, respectively, to the byte register AH and
3429 16-bit word register AX that are actually portions of the 32-bit
3430 register EAX or 64-bit register RAX.
3432 * The `commands' command now accepts a range of breakpoints to modify.
3433 A plain `commands' following a command that creates multiple
3434 breakpoints affects all the breakpoints set by that command. This
3435 applies to breakpoints set by `rbreak', and also applies when a
3436 single `break' command creates multiple breakpoints (e.g.,
3437 breakpoints on overloaded c++ functions).
3439 * The `rbreak' command now accepts a filename specification as part of
3440 its argument, limiting the functions selected by the regex to those
3441 in the specified file.
3443 * Support for remote debugging Windows and SymbianOS shared libraries
3444 from Unix hosts has been improved. Non Windows GDB builds now can
3445 understand target reported file names that follow MS-DOS based file
3446 system semantics, such as file names that include drive letters and
3447 use the backslash character as directory separator. This makes it
3448 possible to transparently use the "set sysroot" and "set
3449 solib-search-path" on Unix hosts to point as host copies of the
3450 target's shared libraries. See the new command "set
3451 target-file-system-kind" described below, and the "Commands to
3452 specify files" section in the user manual for more information.
3456 eval template, expressions...
3457 Convert the values of one or more expressions under the control
3458 of the string template to a command line, and call it.
3460 set target-file-system-kind unix|dos-based|auto
3461 show target-file-system-kind
3462 Set or show the assumed file system kind for target reported file
3465 save breakpoints <filename>
3466 Save all current breakpoint definitions to a file suitable for use
3467 in a later debugging session. To read the saved breakpoint
3468 definitions, use the `source' command.
3470 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3473 info static-tracepoint-markers
3474 Display information about static tracepoint markers in the target.
3476 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3477 Define a static tracepoint by probing a marker at the given
3478 function, line, address, or marker ID.
3482 Enable and disable observer mode.
3484 set may-write-registers on|off
3485 set may-write-memory on|off
3486 set may-insert-breakpoints on|off
3487 set may-insert-tracepoints on|off
3488 set may-insert-fast-tracepoints on|off
3489 set may-interrupt on|off
3490 Set individual permissions for GDB effects on the target. Note that
3491 some of these settings can have undesirable or surprising
3492 consequences, particularly when changed in the middle of a session.
3493 For instance, disabling the writing of memory can prevent
3494 breakpoints from being inserted, cause single-stepping to fail, or
3495 even crash your program, if you disable after breakpoints have been
3496 inserted. However, GDB should not crash.
3498 set record memory-query on|off
3499 show record memory-query
3500 Control whether to stop the inferior if memory changes caused
3501 by an instruction cannot be recorded.
3506 The disassemble command now supports "start,+length" form of two arguments.
3510 ** GDB now provides a new directory location, called the python directory,
3511 where Python scripts written for GDB can be installed. The location
3512 of that directory is <data-directory>/python, where <data-directory>
3513 is the GDB data directory. For more details, see section `Scripting
3514 GDB using Python' in the manual.
3516 ** The GDB Python API now has access to breakpoints, symbols, symbol
3517 tables, program spaces, inferiors, threads and frame's code blocks.
3518 Additionally, GDB Parameters can now be created from the API, and
3519 manipulated via set/show in the CLI.
3521 ** New functions gdb.target_charset, gdb.target_wide_charset,
3522 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3524 ** New exception gdb.GdbError.
3526 ** Pretty-printers are now also looked up in the current program space.
3528 ** Pretty-printers can now be individually enabled and disabled.
3530 ** GDB now looks for names of Python scripts to auto-load in a
3531 special section named `.debug_gdb_scripts', in addition to looking
3532 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3534 * Tracepoint actions were unified with breakpoint commands. In particular,
3535 there are no longer differences in "info break" output for breakpoints and
3536 tracepoints and the "commands" command can be used for both tracepoints and
3537 regular breakpoints.
3541 ARM Symbian arm*-*-symbianelf*
3543 * D language support.
3544 GDB now supports debugging programs written in the D programming
3547 * GDB now supports the extended ptrace interface for PowerPC which is
3548 available since Linux kernel version 2.6.34. This automatically enables
3549 any hardware breakpoints and additional hardware watchpoints available in
3550 the processor. The old ptrace interface exposes just one hardware
3551 watchpoint and no hardware breakpoints.
3553 * GDB is now able to use the Data Value Compare (DVC) register available on
3554 embedded PowerPC processors to implement in hardware simple watchpoint
3555 conditions of the form:
3557 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3559 This works in native GDB running on Linux kernels with the extended ptrace
3560 interface mentioned above.
3562 *** Changes in GDB 7.1
3566 ** Namespace Support
3568 GDB now supports importing of namespaces in C++. This enables the
3569 user to inspect variables from imported namespaces. Support for
3570 namepace aliasing has also been added. So, if a namespace is
3571 aliased in the current scope (e.g. namepace C=A; ) the user can
3572 print variables using the alias (e.g. (gdb) print C::x).
3576 All known bugs relating to the printing of virtual base class were
3577 fixed. It is now possible to call overloaded static methods using a
3582 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3583 and reinterpret_cast<> are now handled by the C++ expression parser.
3587 Xilinx MicroBlaze microblaze-*-*
3592 Xilinx MicroBlaze microblaze
3595 * Multi-program debugging.
3597 GDB now has support for multi-program (a.k.a. multi-executable or
3598 multi-exec) debugging. This allows for debugging multiple inferiors
3599 simultaneously each running a different program under the same GDB
3600 session. See "Debugging Multiple Inferiors and Programs" in the
3601 manual for more information. This implied some user visible changes
3602 in the multi-inferior support. For example, "info inferiors" now
3603 lists inferiors that are not running yet or that have exited
3604 already. See also "New commands" and "New options" below.
3606 * New tracing features
3608 GDB's tracepoint facility now includes several new features:
3610 ** Trace state variables
3612 GDB tracepoints now include support for trace state variables, which
3613 are variables managed by the target agent during a tracing
3614 experiment. They are useful for tracepoints that trigger each
3615 other, so for instance one tracepoint can count hits in a variable,
3616 and then a second tracepoint has a condition that is true when the
3617 count reaches a particular value. Trace state variables share the
3618 $-syntax of GDB convenience variables, and can appear in both
3619 tracepoint actions and condition expressions. Use the "tvariable"
3620 command to create, and "info tvariables" to view; see "Trace State
3621 Variables" in the manual for more detail.
3625 GDB now includes an option for defining fast tracepoints, which
3626 targets may implement more efficiently, such as by installing a jump
3627 into the target agent rather than a trap instruction. The resulting
3628 speedup can be by two orders of magnitude or more, although the
3629 tradeoff is that some program locations on some target architectures
3630 might not allow fast tracepoint installation, for instance if the
3631 instruction to be replaced is shorter than the jump. To request a
3632 fast tracepoint, use the "ftrace" command, with syntax identical to
3633 the regular trace command.
3635 ** Disconnected tracing
3637 It is now possible to detach GDB from the target while it is running
3638 a trace experiment, then reconnect later to see how the experiment
3639 is going. In addition, a new variable disconnected-tracing lets you
3640 tell the target agent whether to continue running a trace if the
3641 connection is lost unexpectedly.
3645 GDB now has the ability to save the trace buffer into a file, and
3646 then use that file as a target, similarly to you can do with
3647 corefiles. You can select trace frames, print data that was
3648 collected in them, and use tstatus to display the state of the
3649 tracing run at the moment that it was saved. To create a trace
3650 file, use "tsave <filename>", and to use it, do "target tfile
3653 ** Circular trace buffer
3655 You can ask the target agent to handle the trace buffer as a
3656 circular buffer, discarding the oldest trace frames to make room for
3657 newer ones, by setting circular-trace-buffer to on. This feature may
3658 not be available for all target agents.
3663 The disassemble command, when invoked with two arguments, now requires
3664 the arguments to be comma-separated.
3667 The info variables command now displays variable definitions. Files
3668 which only declare a variable are not shown.
3671 The source command is now capable of sourcing Python scripts.
3672 This feature is dependent on the debugger being build with Python
3675 Related to this enhancement is also the introduction of a new command
3676 "set script-extension" (see below).
3678 * New commands (for set/show, see "New options" below)
3680 record save [<FILENAME>]
3681 Save a file (in core file format) containing the process record
3682 execution log for replay debugging at a later time.
3684 record restore <FILENAME>
3685 Restore the process record execution log that was saved at an
3686 earlier time, for replay debugging.
3688 add-inferior [-copies <N>] [-exec <FILENAME>]
3691 clone-inferior [-copies <N>] [ID]
3692 Make a new inferior ready to execute the same program another
3693 inferior has loaded.
3698 maint info program-spaces
3699 List the program spaces loaded into GDB.
3701 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3702 show remote interrupt-sequence
3703 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3704 as the sequence to the remote target in order to interrupt the execution.
3705 Ctrl-C is a default. Some system prefers BREAK which is high level of
3706 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3707 Magic SysRq g. It is BREAK signal and character 'g'.
3709 set remote interrupt-on-connect [on | off]
3710 show remote interrupt-on-connect
3711 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3712 remote target when gdb connects to it. This is needed when you debug
3715 set remotebreak [on | off]
3717 Deprecated. Use "set/show remote interrupt-sequence" instead.
3719 tvariable $NAME [ = EXP ]
3720 Create or modify a trace state variable.
3723 List trace state variables and their values.
3725 delete tvariable $NAME ...
3726 Delete one or more trace state variables.
3729 Evaluate the given expressions without collecting anything into the
3730 trace buffer. (Valid in tracepoint actions only.)
3732 ftrace FN / FILE:LINE / *ADDR
3733 Define a fast tracepoint at the given function, line, or address.
3735 * New expression syntax
3737 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3738 GDB now parses 0b101010 identically with 42.
3742 set follow-exec-mode new|same
3743 show follow-exec-mode
3744 Control whether GDB reuses the same inferior across an exec call or
3745 creates a new one. This is useful to be able to restart the old
3746 executable after the inferior having done an exec call.
3748 set default-collect EXPR, ...
3749 show default-collect
3750 Define a list of expressions to be collected at each tracepoint.
3751 This is a useful way to ensure essential items are not overlooked,
3752 such as registers or a critical global variable.
3754 set disconnected-tracing
3755 show disconnected-tracing
3756 If set to 1, the target is instructed to continue tracing if it
3757 loses its connection to GDB. If 0, the target is to stop tracing
3760 set circular-trace-buffer
3761 show circular-trace-buffer
3762 If set to on, the target is instructed to use a circular trace buffer
3763 and discard the oldest trace frames instead of stopping the trace due
3764 to a full trace buffer. If set to off, the trace stops when the buffer
3765 fills up. Some targets may not support this.
3767 set script-extension off|soft|strict
3768 show script-extension
3769 If set to "off", the debugger does not perform any script language
3770 recognition, and all sourced files are assumed to be GDB scripts.
3771 If set to "soft" (the default), files are sourced according to
3772 filename extension, falling back to GDB scripts if the first
3774 If set to "strict", files are sourced according to filename extension.
3776 set ada trust-PAD-over-XVS on|off
3777 show ada trust-PAD-over-XVS
3778 If off, activate a workaround against a bug in the debugging information
3779 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3780 the GCC sources for more information about the GNAT encoding and
3781 PAD types in particular). It is always safe to set this option to
3782 off, but this introduces a slight performance penalty. The default
3785 * Python API Improvements
3787 ** GDB provides the new class gdb.LazyString. This is useful in
3788 some pretty-printing cases. The new method gdb.Value.lazy_string
3789 provides a simple way to create objects of this type.
3791 ** The fields returned by gdb.Type.fields now have an
3792 `is_base_class' attribute.
3794 ** The new method gdb.Type.range returns the range of an array type.
3796 ** The new method gdb.parse_and_eval can be used to parse and
3797 evaluate an expression.
3799 * New remote packets
3802 Define a trace state variable.
3805 Get the current value of a trace state variable.
3808 Set desired tracing behavior upon disconnection.
3811 Set the trace buffer to be linear or circular.
3814 Get data about the tracepoints currently in use.
3818 Process record now works correctly with hardware watchpoints.
3820 Multiple bug fixes have been made to the mips-irix port, making it
3821 much more reliable. In particular:
3822 - Debugging threaded applications is now possible again. Previously,
3823 GDB would hang while starting the program, or while waiting for
3824 the program to stop at a breakpoint.
3825 - Attaching to a running process no longer hangs.
3826 - An error occurring while loading a core file has been fixed.
3827 - Changing the value of the PC register now works again. This fixes
3828 problems observed when using the "jump" command, or when calling
3829 a function from GDB, or even when assigning a new value to $pc.
3830 - With the "finish" and "return" commands, the return value for functions
3831 returning a small array is now correctly printed.
3832 - It is now possible to break on shared library code which gets executed
3833 during a shared library init phase (code executed while executing
3834 their .init section). Previously, the breakpoint would have no effect.
3835 - GDB is now able to backtrace through the signal handler for
3836 non-threaded programs.
3838 PIE (Position Independent Executable) programs debugging is now supported.
3839 This includes debugging execution of PIC (Position Independent Code) shared
3840 libraries although for that, it should be possible to run such libraries as an
3843 *** Changes in GDB 7.0
3845 * GDB now has an interface for JIT compilation. Applications that
3846 dynamically generate code can create symbol files in memory and register
3847 them with GDB. For users, the feature should work transparently, and
3848 for JIT developers, the interface is documented in the GDB manual in the
3849 "JIT Compilation Interface" chapter.
3851 * Tracepoints may now be conditional. The syntax is as for
3852 breakpoints; either an "if" clause appended to the "trace" command,
3853 or the "condition" command is available. GDB sends the condition to
3854 the target for evaluation using the same bytecode format as is used
3855 for tracepoint actions.
3857 * The disassemble command now supports: an optional /r modifier, print the
3858 raw instructions in hex as well as in symbolic form, and an optional /m
3859 modifier to print mixed source+assembly.
3861 * Process record and replay
3863 In a architecture environment that supports ``process record and
3864 replay'', ``process record and replay'' target can record a log of
3865 the process execution, and replay it with both forward and reverse
3868 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3869 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3870 set execution-direction {forward|reverse}, for targets that support
3873 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3874 feature is available with a native GDB running on kernel version
3877 * GDB now has support for multi-byte and wide character sets on the
3878 target. Strings whose character type is wchar_t, char16_t, or
3879 char32_t are now correctly printed. GDB supports wide- and unicode-
3880 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3881 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3882 `printf'. This feature requires iconv to work properly; if your
3883 system does not have a working iconv, GDB can use GNU libiconv. See
3884 the installation instructions for more information.
3886 * GDB now supports automatic retrieval of shared library files from
3887 remote targets. To use this feature, specify a system root that begins
3888 with the `remote:' prefix, either via the `set sysroot' command or via
3889 the `--with-sysroot' configure-time option.
3891 * "info sharedlibrary" now takes an optional regex of libraries to show,
3892 and it now reports if a shared library has no debugging information.
3894 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3895 now complete on file names.
3897 * When completing in expressions, gdb will attempt to limit
3898 completions to allowable structure or union fields, where appropriate.
3899 For instance, consider:
3901 # struct example { int f1; double f2; };
3902 # struct example variable;
3905 If the user types TAB at the end of this command line, the available
3906 completions will be "f1" and "f2".
3908 * Inlined functions are now supported. They show up in backtraces, and
3909 the "step", "next", and "finish" commands handle them automatically.
3911 * GDB now supports the token-splicing (##) and stringification (#)
3912 operators when expanding macros. It also supports variable-arity
3915 * GDB now supports inspecting extra signal information, exported by
3916 the new $_siginfo convenience variable. The feature is currently
3917 implemented on linux ARM, i386 and amd64.
3919 * GDB can now display the VFP floating point registers and NEON vector
3920 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3921 can provide these registers (requires Linux 2.6.30 or later). Remote
3922 and simulator targets may also provide them.
3924 * New remote packets
3927 Search memory for a sequence of bytes.
3930 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3931 operation over reliable transport links. Use of this packet is
3932 controlled by the `set remote noack-packet' command.
3935 Kill the process with the specified process ID. Use this in preference
3936 to `k' when multiprocess protocol extensions are supported.
3939 Obtains additional operating system information
3943 Read or write additional signal information.
3945 * Removed remote protocol undocumented extension
3947 An undocumented extension to the remote protocol's `S' stop reply
3948 packet that permited the stub to pass a process id was removed.
3949 Remote servers should use the `T' stop reply packet instead.
3951 * GDB now supports multiple function calling conventions according to the
3952 DWARF-2 DW_AT_calling_convention function attribute.
3954 * The SH target utilizes the aforementioned change to distinguish between gcc
3955 and Renesas calling convention. It also adds the new CLI commands
3956 `set/show sh calling-convention'.
3958 * GDB can now read compressed debug sections, as produced by GNU gold
3959 with the --compress-debug-sections=zlib flag.
3961 * 64-bit core files are now supported on AIX.
3963 * Thread switching is now supported on Tru64.
3965 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3966 which will be allocated using malloc later in program execution.
3968 * The qXfer:libraries:read remote procotol packet now allows passing a
3969 list of section offsets.
3971 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3972 conditions handling signals delivered during attach or thread creation
3973 have also been fixed.
3975 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3976 From the user's standpoint, all unqualified instances of True and False
3977 are treated as the standard definitions, regardless of context.
3979 * GDB now parses C++ symbol and type names more flexibly. For
3982 template<typename T> class C { };
3985 GDB will now correctly handle all of:
3987 ptype C<char const *>
3988 ptype C<char const*>
3989 ptype C<const char *>
3990 ptype C<const char*>
3992 * New features in the GDB remote stub, gdbserver
3994 - The "--wrapper" command-line argument tells gdbserver to use a
3995 wrapper program to launch programs for debugging.
3997 - On PowerPC and S/390 targets, it is now possible to use a single
3998 gdbserver executable to debug both 32-bit and 64-bit programs.
3999 (This requires gdbserver itself to be built as a 64-bit executable.)
4001 - gdbserver uses the new noack protocol mode for TCP connections to
4002 reduce communications latency, if also supported and enabled in GDB.
4004 - Support for the sparc64-linux-gnu target is now included in
4007 - The amd64-linux build of gdbserver now supports debugging both
4008 32-bit and 64-bit programs.
4010 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4011 now support hardware watchpoints, and will use them automatically
4016 GDB now has support for scripting using Python. Whether this is
4017 available is determined at configure time.
4019 New GDB commands can now be written in Python.
4021 * Ada tasking support
4023 Ada tasks can now be inspected in GDB. The following commands have
4027 Print the list of Ada tasks.
4029 Print detailed information about task number N.
4031 Print the task number of the current task.
4033 Switch the context of debugging to task number N.
4035 * Support for user-defined prefixed commands. The "define" command can
4036 add new commands to existing prefixes, e.g. "target".
4038 * Multi-inferior, multi-process debugging.
4040 GDB now has generalized support for multi-inferior debugging. See
4041 "Debugging Multiple Inferiors" in the manual for more information.
4042 Although availability still depends on target support, the command
4043 set is more uniform now. The GNU/Linux specific multi-forks support
4044 has been migrated to this new framework. This implied some user
4045 visible changes; see "New commands" and also "Removed commands"
4048 * Target descriptions can now describe the target OS ABI. See the
4049 "Target Description Format" section in the user manual for more
4052 * Target descriptions can now describe "compatible" architectures
4053 to indicate that the target can execute applications for a different
4054 architecture in addition to those for the main target architecture.
4055 See the "Target Description Format" section in the user manual for
4058 * Multi-architecture debugging.
4060 GDB now includes general supports for debugging applications on
4061 hybrid systems that use more than one single processor architecture
4062 at the same time. Each such hybrid architecture still requires
4063 specific support to be added. The only hybrid architecture supported
4064 in this version of GDB is the Cell Broadband Engine.
4066 * GDB now supports integrated debugging of Cell/B.E. applications that
4067 use both the PPU and SPU architectures. To enable support for hybrid
4068 Cell/B.E. debugging, you need to configure GDB to support both the
4069 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4070 --enable-targets configure option.
4072 * Non-stop mode debugging.
4074 For some targets, GDB now supports an optional mode of operation in
4075 which you can examine stopped threads while other threads continue
4076 to execute freely. This is referred to as non-stop mode, with the
4077 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4078 section in the user manual for more information.
4080 To be able to support remote non-stop debugging, a remote stub needs
4081 to implement the non-stop mode remote protocol extensions, as
4082 described in the "Remote Non-Stop" section of the user manual. The
4083 GDB remote stub, gdbserver, has been adjusted to support these
4084 extensions on linux targets.
4086 * New commands (for set/show, see "New options" below)
4088 catch syscall [NAME(S) | NUMBER(S)]
4089 Catch system calls. Arguments, which should be names of system
4090 calls or their numbers, mean catch only those syscalls. Without
4091 arguments, every syscall will be caught. When the inferior issues
4092 any of the specified syscalls, GDB will stop and announce the system
4093 call, both when it is called and when its call returns. This
4094 feature is currently available with a native GDB running on the
4095 Linux Kernel, under the following architectures: x86, x86_64,
4096 PowerPC and PowerPC64.
4098 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4100 Search memory for a sequence of bytes.
4102 maint set python print-stack
4103 maint show python print-stack
4104 Show a stack trace when an error is encountered in a Python script.
4107 Invoke CODE by passing it to the Python interpreter.
4112 These allow macros to be defined, undefined, and listed
4116 Show operating system information about processes.
4119 List the inferiors currently under GDB's control.
4122 Switch focus to inferior number NUM.
4125 Detach from inferior number NUM.
4128 Kill inferior number NUM.
4132 set spu stop-on-load
4133 show spu stop-on-load
4134 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4136 set spu auto-flush-cache
4137 show spu auto-flush-cache
4138 Control whether to automatically flush the software-managed cache
4139 during Cell/B.E. debugging.
4141 set sh calling-convention
4142 show sh calling-convention
4143 Control the calling convention used when calling SH target functions.
4146 show debug timestamp
4147 Control display of timestamps with GDB debugging output.
4149 set disassemble-next-line
4150 show disassemble-next-line
4151 Control display of disassembled source lines or instructions when
4154 set remote noack-packet
4155 show remote noack-packet
4156 Set/show the use of remote protocol QStartNoAckMode packet. See above
4157 under "New remote packets."
4159 set remote query-attached-packet
4160 show remote query-attached-packet
4161 Control use of remote protocol `qAttached' (query-attached) packet.
4163 set remote read-siginfo-object
4164 show remote read-siginfo-object
4165 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4168 set remote write-siginfo-object
4169 show remote write-siginfo-object
4170 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4173 set remote reverse-continue
4174 show remote reverse-continue
4175 Control use of remote protocol 'bc' (reverse-continue) packet.
4177 set remote reverse-step
4178 show remote reverse-step
4179 Control use of remote protocol 'bs' (reverse-step) packet.
4181 set displaced-stepping
4182 show displaced-stepping
4183 Control displaced stepping mode. Displaced stepping is a way to
4184 single-step over breakpoints without removing them from the debuggee.
4185 Also known as "out-of-line single-stepping".
4188 show debug displaced
4189 Control display of debugging info for displaced stepping.
4191 maint set internal-error
4192 maint show internal-error
4193 Control what GDB does when an internal error is detected.
4195 maint set internal-warning
4196 maint show internal-warning
4197 Control what GDB does when an internal warning is detected.
4202 Use a wrapper program to launch programs for debugging.
4204 set multiple-symbols (all|ask|cancel)
4205 show multiple-symbols
4206 The value of this variable can be changed to adjust the debugger behavior
4207 when an expression or a breakpoint location contains an ambiguous symbol
4208 name (an overloaded function name, for instance).
4210 set breakpoint always-inserted
4211 show breakpoint always-inserted
4212 Keep breakpoints always inserted in the target, as opposed to inserting
4213 them when resuming the target, and removing them when the target stops.
4214 This option can improve debugger performance on slow remote targets.
4216 set arm fallback-mode (arm|thumb|auto)
4217 show arm fallback-mode
4218 set arm force-mode (arm|thumb|auto)
4220 These commands control how ARM GDB determines whether instructions
4221 are ARM or Thumb. The default for both settings is auto, which uses
4222 the current CPSR value for instructions without symbols; previous
4223 versions of GDB behaved as if "set arm fallback-mode arm".
4225 set disable-randomization
4226 show disable-randomization
4227 Standalone programs run with the virtual address space randomization enabled
4228 by default on some platforms. This option keeps the addresses stable across
4229 multiple debugging sessions.
4233 Control whether other threads are stopped or not when some thread hits
4238 Requests that asynchronous execution is enabled in the target, if available.
4239 In this case, it's possible to resume target in the background, and interact
4240 with GDB while the target is running. "show target-async" displays the
4241 current state of asynchronous execution of the target.
4243 set target-wide-charset
4244 show target-wide-charset
4245 The target-wide-charset is the name of the character set that GDB
4246 uses when printing characters whose type is wchar_t.
4248 set tcp auto-retry (on|off)
4250 set tcp connect-timeout
4251 show tcp connect-timeout
4252 These commands allow GDB to retry failed TCP connections to a remote stub
4253 with a specified timeout period; this is useful if the stub is launched
4254 in parallel with GDB but may not be ready to accept connections immediately.
4256 set libthread-db-search-path
4257 show libthread-db-search-path
4258 Control list of directories which GDB will search for appropriate
4261 set schedule-multiple (on|off)
4262 show schedule-multiple
4263 Allow GDB to resume all threads of all processes or only threads of
4264 the current process.
4268 Use more aggressive caching for accesses to the stack. This improves
4269 performance of remote debugging (particularly backtraces) without
4270 affecting correctness.
4272 set interactive-mode (on|off|auto)
4273 show interactive-mode
4274 Control whether GDB runs in interactive mode (on) or not (off).
4275 When in interactive mode, GDB waits for the user to answer all
4276 queries. Otherwise, GDB does not wait and assumes the default
4277 answer. When set to auto (the default), GDB determines which
4278 mode to use based on the stdin settings.
4283 For program forks, this is replaced by the new more generic `info
4284 inferiors' command. To list checkpoints, you can still use the
4285 `info checkpoints' command, which was an alias for the `info forks'
4289 Replaced by the new `inferior' command. To switch between
4290 checkpoints, you can still use the `restart' command, which was an
4291 alias for the `fork' command.
4294 This is removed, since some targets don't have a notion of
4295 processes. To switch between processes, you can still use the
4296 `inferior' command using GDB's own inferior number.
4299 For program forks, this is replaced by the new more generic `kill
4300 inferior' command. To delete a checkpoint, you can still use the
4301 `delete checkpoint' command, which was an alias for the `delete
4305 For program forks, this is replaced by the new more generic `detach
4306 inferior' command. To detach a checkpoint, you can still use the
4307 `detach checkpoint' command, which was an alias for the `detach
4310 * New native configurations
4312 x86/x86_64 Darwin i[34567]86-*-darwin*
4314 x86_64 MinGW x86_64-*-mingw*
4318 Lattice Mico32 lm32-*
4319 x86 DICOS i[34567]86-*-dicos*
4320 x86_64 DICOS x86_64-*-dicos*
4323 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4324 (mingw32ce) debugging.
4330 These commands were actually not implemented on any target.
4332 *** Changes in GDB 6.8
4334 * New native configurations
4336 NetBSD/hppa hppa*-*netbsd*
4337 Xtensa GNU/Linux xtensa*-*-linux*
4341 NetBSD/hppa hppa*-*-netbsd*
4342 Xtensa GNU/Lunux xtensa*-*-linux*
4344 * Change in command line behavior -- corefiles vs. process ids.
4346 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4347 attaching to process NUMBER fails, GDB no longer attempts to open a
4348 core file named NUMBER. Attaching to a program using the -c option
4349 is no longer supported. Instead, use the '-p' or '--pid' options.
4351 * GDB can now be built as a native debugger for debugging Windows x86
4352 (mingw32) Portable Executable (PE) programs.
4354 * Pending breakpoints no longer change their number when their address
4357 * GDB now supports breakpoints with multiple locations,
4358 including breakpoints on C++ constructors, inside C++ templates,
4359 and in inlined functions.
4361 * GDB's ability to debug optimized code has been improved. GDB more
4362 accurately identifies function bodies and lexical blocks that occupy
4363 more than one contiguous range of addresses.
4365 * Target descriptions can now describe registers for PowerPC.
4367 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4368 registers on PowerPC targets.
4370 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4371 targets even when the libthread_db library is not available.
4373 * The GDB remote stub, gdbserver, now supports the new file transfer
4374 commands (remote put, remote get, and remote delete).
4376 * The GDB remote stub, gdbserver, now supports run and attach in
4377 extended-remote mode.
4379 * hppa*64*-*-hpux11* target broken
4380 The debugger is unable to start a program and fails with the following
4381 error: "Error trying to get information about dynamic linker".
4382 The gdb-6.7 release is also affected.
4384 * GDB now supports the --enable-targets= configure option to allow
4385 building a single GDB executable that supports multiple remote
4386 target architectures.
4388 * GDB now supports debugging C and C++ programs which use the
4389 Decimal Floating Point extension. In addition, the PowerPC target
4390 now has a set of pseudo-registers to inspect decimal float values
4391 stored in two consecutive float registers.
4393 * The -break-insert MI command can optionally create pending
4396 * Improved support for debugging Ada
4397 Many improvements to the Ada language support have been made. These
4399 - Better support for Ada2005 interface types
4400 - Improved handling of arrays and slices in general
4401 - Better support for Taft-amendment types
4402 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4404 - Improved command completion in Ada
4407 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4412 set print frame-arguments (all|scalars|none)
4413 show print frame-arguments
4414 The value of this variable can be changed to control which argument
4415 values should be printed by the debugger when displaying a frame.
4420 Transfer files to and from a remote target, and delete remote files.
4427 Transfer files to and from a remote target, and delete remote files.
4429 * New remote packets
4436 Open, close, read, write, and delete files on the remote system.
4439 Attach to an existing process on the remote system, in extended-remote
4443 Run a new process on the remote system, in extended-remote mode.
4445 *** Changes in GDB 6.7
4447 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4448 bfd, libiberty and opcodes, as revealed by static analysis donated by
4449 Coverity, Inc. (http://scan.coverity.com).
4451 * When looking up multiply-defined global symbols, GDB will now prefer the
4452 symbol definition in the current shared library if it was built using the
4453 -Bsymbolic linker option.
4455 * When the Text User Interface (TUI) is not configured, GDB will now
4456 recognize the -tui command-line option and print a message that the TUI
4459 * The GDB remote stub, gdbserver, now has lower overhead for high
4460 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4462 * GDB for MIPS targets now autodetects whether a remote target provides
4463 32-bit or 64-bit register values.
4465 * Support for C++ member pointers has been improved.
4467 * GDB now understands XML target descriptions, which specify the
4468 target's overall architecture. GDB can read a description from
4469 a local file or over the remote serial protocol.
4471 * Vectors of single-byte data use a new integer type which is not
4472 automatically displayed as character or string data.
4474 * The /s format now works with the print command. It displays
4475 arrays of single-byte integers and pointers to single-byte integers
4478 * Target descriptions can now describe target-specific registers,
4479 for architectures which have implemented the support (currently
4480 only ARM, M68K, and MIPS).
4482 * GDB and the GDB remote stub, gdbserver, now support the XScale
4485 * The GDB remote stub, gdbserver, has been updated to support
4486 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4487 has been rewritten to use the standard GDB remote protocol.
4489 * GDB can now step into C++ functions which are called through thunks.
4491 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4493 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4494 layout. It also supports a TextSeg= and DataSeg= response when only
4495 segment base addresses (rather than offsets) are available.
4497 * The /i format now outputs any trailing branch delay slot instructions
4498 immediately following the last instruction within the count specified.
4500 * The GDB remote protocol "T" stop reply packet now supports a
4501 "library" response. Combined with the new "qXfer:libraries:read"
4502 packet, this response allows GDB to debug shared libraries on targets
4503 where the operating system manages the list of loaded libraries (e.g.
4504 Windows and SymbianOS).
4506 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4507 (DLLs) on Windows and Windows CE targets.
4509 * GDB now supports a faster verification that a .debug file matches its binary
4510 according to its build-id signature, if the signature is present.
4516 Enable or disable hardware flow control (RTS/CTS) on the serial port
4517 when debugging using remote targets.
4519 set mem inaccessible-by-default
4520 show mem inaccessible-by-default
4521 If the target supplies a memory map, for instance via the remote
4522 protocol's "qXfer:memory-map:read" packet, setting this variable
4523 prevents GDB from accessing memory outside the memory map. This
4524 is useful for targets with memory mapped registers or which react
4525 badly to accesses of unmapped address space.
4527 set breakpoint auto-hw
4528 show breakpoint auto-hw
4529 If the target supplies a memory map, for instance via the remote
4530 protocol's "qXfer:memory-map:read" packet, setting this variable
4531 lets GDB use hardware breakpoints automatically for memory regions
4532 where it can not use software breakpoints. This covers both the
4533 "break" command and internal breakpoints used for other commands
4534 including "next" and "finish".
4537 catch exception unhandled
4538 Stop the program execution when Ada exceptions are raised.
4541 Stop the program execution when an Ada assertion failed.
4545 Set an alternate system root for target files. This is a more
4546 general version of "set solib-absolute-prefix", which is now
4547 an alias to "set sysroot".
4550 Provide extended SPU facility status information. This set of
4551 commands is available only when debugging the Cell/B.E. SPU
4554 * New native configurations
4556 OpenBSD/sh sh*-*openbsd*
4559 unset tdesc filename
4561 Use the specified local file as an XML target description, and do
4562 not query the target for its built-in description.
4566 OpenBSD/sh sh*-*-openbsd*
4567 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4568 Toshiba Media Processor mep-elf
4570 * New remote packets
4573 Ignore the specified signals; pass them directly to the debugged program
4574 without stopping other threads or reporting them to GDB.
4576 qXfer:features:read:
4577 Read an XML target description from the target, which describes its
4582 Read or write contents of an spufs file on the target system. These
4583 packets are available only on the Cell/B.E. SPU architecture.
4585 qXfer:libraries:read:
4586 Report the loaded shared libraries. Combined with new "T" packet
4587 response, this packet allows GDB to debug shared libraries on
4588 targets where the operating system manages the list of loaded
4589 libraries (e.g. Windows and SymbianOS).
4593 Support for these obsolete configurations has been removed.
4601 i[34567]86-*-lynxos*
4602 i[34567]86-*-netware*
4603 i[34567]86-*-sco3.2v5*
4604 i[34567]86-*-sco3.2v4*
4606 i[34567]86-*-sysv4.2*
4609 i[34567]86-*-unixware2*
4610 i[34567]86-*-unixware*
4619 * Other removed features
4626 Various m68k-only ROM monitors.
4633 Various Renesas ROM monitors and debugging interfaces for SH and
4638 Support for a Macraigor serial interface to on-chip debugging.
4639 GDB does not directly support the newer parallel or USB
4644 A debug information format. The predecessor to DWARF 2 and
4645 DWARF 3, which are still supported.
4647 Support for the HP aCC compiler on HP-UX/PA-RISC
4649 SOM-encapsulated symbolic debugging information, automatic
4650 invocation of pxdb, and the aCC custom C++ ABI. This does not
4651 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4652 with aCC can still be debugged on an assembly level.
4654 MIPS ".pdr" sections
4656 A MIPS-specific format used to describe stack frame layout
4657 in debugging information.
4661 GDB could work with an older version of Guile to debug
4662 the interpreter and Scheme programs running in it.
4664 set mips stack-arg-size
4665 set mips saved-gpreg-size
4667 Use "set mips abi" to control parameter passing for MIPS.
4669 *** Changes in GDB 6.6
4674 Cell Broadband Engine SPU spu-elf
4676 * GDB can now be configured as a cross-debugger targeting native Windows
4677 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4678 running on a Windows system over TCP/IP to debug Windows programs.
4680 * The GDB remote stub, gdbserver, has been updated to support Windows and
4681 Cygwin debugging. Both single-threaded and multi-threaded programs are
4684 * The "set trust-readonly-sections" command works again. This command was
4685 broken in GDB 6.3, 6.4, and 6.5.
4687 * The "load" command now supports writing to flash memory, if the remote
4688 stub provides the required support.
4690 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4691 longer requires symbolic debug information (e.g. DWARF-2).
4696 unset substitute-path
4697 show substitute-path
4698 Manage a list of substitution rules that GDB uses to rewrite the name
4699 of the directories where the sources are located. This can be useful
4700 for instance when the sources were moved to a different location
4701 between compilation and debugging.
4705 Print each CLI command as it is executed. Each command is prefixed with
4706 a number of `+' symbols representing the nesting depth.
4707 The source command now has a `-v' option to enable the same feature.
4711 The ARM Demon monitor support (RDP protocol, "target rdp").
4713 Kernel Object Display, an embedded debugging feature which only worked with
4714 an obsolete version of Cisco IOS.
4716 The 'set download-write-size' and 'show download-write-size' commands.
4718 * New remote packets
4721 Tell a stub about GDB client features, and request remote target features.
4722 The first feature implemented is PacketSize, which allows the target to
4723 specify the size of packets it can handle - to minimize the number of
4724 packets required and improve performance when connected to a remote
4728 Fetch an OS auxilliary vector from the remote stub. This packet is a
4729 more efficient replacement for qPart:auxv:read.
4731 qXfer:memory-map:read:
4732 Fetch a memory map from the remote stub, including information about
4733 RAM, ROM, and flash memory devices.
4738 Erase and program a flash memory device.
4740 * Removed remote packets
4743 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4744 used it, and only gdbserver implemented it.
4746 *** Changes in GDB 6.5
4750 Renesas M32C/M16C m32c-elf
4752 Morpho Technologies ms1 ms1-elf
4756 init-if-undefined Initialize a convenience variable, but
4757 only if it doesn't already have a value.
4759 The following commands are presently only implemented for native GNU/Linux:
4761 checkpoint Save a snapshot of the program state.
4763 restart <n> Return the program state to a
4764 previously saved state.
4766 info checkpoints List currently saved checkpoints.
4768 delete-checkpoint <n> Delete a previously saved checkpoint.
4770 set|show detach-on-fork Tell gdb whether to detach from a newly
4771 forked process, or to keep debugging it.
4773 info forks List forks of the user program that
4774 are available to be debugged.
4776 fork <n> Switch to debugging one of several
4777 forks of the user program that are
4778 available to be debugged.
4780 delete-fork <n> Delete a fork from the list of forks
4781 that are available to be debugged (and
4782 kill the forked process).
4784 detach-fork <n> Delete a fork from the list of forks
4785 that are available to be debugged (and
4786 allow the process to continue).
4790 Morpho Technologies ms2 ms1-elf
4792 * Improved Windows host support
4794 GDB now builds as a cross debugger hosted on i686-mingw32, including
4795 native console support, and remote communications using either
4796 network sockets or serial ports.
4798 * Improved Modula-2 language support
4800 GDB can now print most types in the Modula-2 syntax. This includes:
4801 basic types, set types, record types, enumerated types, range types,
4802 pointer types and ARRAY types. Procedure var parameters are correctly
4803 printed and hexadecimal addresses and character constants are also
4804 written in the Modula-2 syntax. Best results can be obtained by using
4805 GNU Modula-2 together with the -gdwarf-2 command line option.
4809 The ARM rdi-share module.
4811 The Netware NLM debug server.
4813 *** Changes in GDB 6.4
4815 * New native configurations
4817 OpenBSD/arm arm*-*-openbsd*
4818 OpenBSD/mips64 mips64-*-openbsd*
4822 Morpho Technologies ms1 ms1-elf
4824 * New command line options
4826 --batch-silent As for --batch, but totally silent.
4827 --return-child-result The debugger will exist with the same value
4828 the child (debugged) program exited with.
4829 --eval-command COMMAND, -ex COMMAND
4830 Execute a single GDB CLI command. This may be
4831 specified multiple times and in conjunction
4832 with the --command (-x) option.
4834 * Deprecated commands removed
4836 The following commands, that were deprecated in 2000, have been
4840 set|show arm disassembly-flavor set|show arm disassembler
4841 othernames set arm disassembler
4842 set|show remotedebug set|show debug remote
4843 set|show archdebug set|show debug arch
4844 set|show eventdebug set|show debug event
4847 * New BSD user-level threads support
4849 It is now possible to debug programs using the user-level threads
4850 library on OpenBSD and FreeBSD. Currently supported (target)
4853 FreeBSD/amd64 x86_64-*-freebsd*
4854 FreeBSD/i386 i386-*-freebsd*
4855 OpenBSD/i386 i386-*-openbsd*
4857 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4858 are not yet supported.
4860 * New support for Matsushita MN10300 w/sim added
4861 (Work in progress). mn10300-elf.
4863 * REMOVED configurations and files
4865 VxWorks and the XDR protocol *-*-vxworks
4866 Motorola MCORE mcore-*-*
4867 National Semiconductor NS32000 ns32k-*-*
4869 * New "set print array-indexes" command
4871 After turning this setting "on", GDB prints the index of each element
4872 when displaying arrays. The default is "off" to preserve the previous
4875 * VAX floating point support
4877 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4879 * User-defined command support
4881 In addition to using $arg0..$arg9 for argument passing, it is now possible
4882 to use $argc to determine now many arguments have been passed. See the
4883 section on user-defined commands in the user manual for more information.
4885 *** Changes in GDB 6.3:
4887 * New command line option
4889 GDB now accepts -l followed by a number to set the timeout for remote
4892 * GDB works with GCC -feliminate-dwarf2-dups
4894 GDB now supports a more compact representation of DWARF-2 debug
4895 information using DW_FORM_ref_addr references. These are produced
4896 by GCC with the option -feliminate-dwarf2-dups and also by some
4897 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4898 to use -feliminate-dwarf2-dups.
4900 * Internationalization
4902 When supported by the host system, GDB will be built with
4903 internationalization (libintl). The task of marking up the sources is
4904 continued, we're looking forward to our first translation.
4908 Initial support for debugging programs compiled with the GNAT
4909 implementation of the Ada programming language has been integrated
4910 into GDB. In this release, support is limited to expression evaluation.
4912 * New native configurations
4914 GNU/Linux/m32r m32r-*-linux-gnu
4918 GDB's remote protocol now includes support for the 'p' packet. This
4919 packet is used to fetch individual registers from a remote inferior.
4921 * END-OF-LIFE registers[] compatibility module
4923 GDB's internal register infrastructure has been completely rewritten.
4924 The new infrastructure making possible the implementation of key new
4925 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4928 GDB 6.3 will be the last release to include the the registers[]
4929 compatibility module that allowed out-of-date configurations to
4930 continue to work. This change directly impacts the following
4940 powerpc bdm protocol
4942 Unless there is activity to revive these configurations, they will be
4943 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4945 * OBSOLETE configurations and files
4947 Configurations that have been declared obsolete in this release have
4948 been commented out. Unless there is activity to revive these
4949 configurations, the next release of GDB will have their sources
4950 permanently REMOVED.
4959 *** Changes in GDB 6.2.1:
4961 * MIPS `break main; run' gave an heuristic-fence-post warning
4963 When attempting to run even a simple program, a warning about
4964 heuristic-fence-post being hit would be reported. This problem has
4967 * MIPS IRIX 'long double' crashed GDB
4969 When examining a long double variable, GDB would get a segmentation
4970 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4971 IRIX long double values).
4975 A bug in the VAX stack code was causing problems with the "next"
4976 command. This problem has been fixed.
4978 *** Changes in GDB 6.2:
4980 * Fix for ``many threads''
4982 On GNU/Linux systems that use the NPTL threads library, a program
4983 rapidly creating and deleting threads would confuse GDB leading to the
4986 ptrace: No such process.
4987 thread_db_get_info: cannot get thread info: generic error
4989 This problem has been fixed.
4991 * "-async" and "-noasync" options removed.
4993 Support for the broken "-noasync" option has been removed (it caused
4996 * New ``start'' command.
4998 This command runs the program until the begining of the main procedure.
5000 * New BSD Kernel Data Access Library (libkvm) interface
5002 Using ``target kvm'' it is now possible to debug kernel core dumps and
5003 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5004 platforms. Currently supported (native-only) configurations are:
5006 FreeBSD/amd64 x86_64-*-freebsd*
5007 FreeBSD/i386 i?86-*-freebsd*
5008 NetBSD/i386 i?86-*-netbsd*
5009 NetBSD/m68k m68*-*-netbsd*
5010 NetBSD/sparc sparc-*-netbsd*
5011 OpenBSD/amd64 x86_64-*-openbsd*
5012 OpenBSD/i386 i?86-*-openbsd*
5013 OpenBSD/m68k m68*-openbsd*
5014 OpenBSD/sparc sparc-*-openbsd*
5016 * Signal trampoline code overhauled
5018 Many generic problems with GDB's signal handling code have been fixed.
5019 These include: backtraces through non-contiguous stacks; recognition
5020 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5021 call; backtrace through a signal trampoline; step into and out of
5022 signal handlers; and single-stepping in the signal trampoline.
5024 Please note that kernel bugs are a limiting factor here. These
5025 features have been shown to work on an s390 GNU/Linux system that
5026 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5028 * Cygwin support for DWARF 2 added.
5030 * New native configurations
5032 GNU/Linux/hppa hppa*-*-linux*
5033 OpenBSD/hppa hppa*-*-openbsd*
5034 OpenBSD/m68k m68*-*-openbsd*
5035 OpenBSD/m88k m88*-*-openbsd*
5036 OpenBSD/powerpc powerpc-*-openbsd*
5037 NetBSD/vax vax-*-netbsd*
5038 OpenBSD/vax vax-*-openbsd*
5040 * END-OF-LIFE frame compatibility module
5042 GDB's internal frame infrastructure has been completely rewritten.
5043 The new infrastructure making it possible to support key new features
5044 including DWARF 2 Call Frame Information. To aid in the task of
5045 migrating old configurations to this new infrastructure, a
5046 compatibility module, that allowed old configurations to continue to
5047 work, was also included.
5049 GDB 6.2 will be the last release to include this frame compatibility
5050 module. This change directly impacts the following configurations:
5060 Unless there is activity to revive these configurations, they will be
5061 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5063 * REMOVED configurations and files
5065 Sun 3, running SunOS 3 m68*-*-sunos3*
5066 Sun 3, running SunOS 4 m68*-*-sunos4*
5067 Sun 2, running SunOS 3 m68000-*-sunos3*
5068 Sun 2, running SunOS 4 m68000-*-sunos4*
5069 Motorola 680x0 running LynxOS m68*-*-lynxos*
5070 AT&T 3b1/Unix pc m68*-att-*
5071 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5072 decstation mips-dec-* mips-little-*
5073 riscos mips-*-riscos* mips-*-sysv*
5074 sonymips mips-sony-*
5075 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5077 *** Changes in GDB 6.1.1:
5079 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5081 The TUI (Text-mode User Interface) is now built as part of a default
5082 GDB configuration. It is enabled by either selecting the TUI with the
5083 command line option "-i=tui" or by running the separate "gdbtui"
5084 program. For more information on the TUI, see the manual "Debugging
5087 * Pending breakpoint support (also included in GDB 6.1)
5089 Support has been added to allow you to specify breakpoints in shared
5090 libraries that have not yet been loaded. If a breakpoint location
5091 cannot be found, and the "breakpoint pending" option is set to auto,
5092 GDB queries you if you wish to make the breakpoint pending on a future
5093 shared-library load. If and when GDB resolves the breakpoint symbol,
5094 the pending breakpoint is removed as one or more regular breakpoints
5097 Pending breakpoints are very useful for GCJ Java debugging.
5099 * Fixed ISO-C build problems
5101 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5102 non ISO-C code that stopped them being built using a more strict ISO-C
5103 compiler (e.g., IBM's C compiler).
5105 * Fixed build problem on IRIX 5
5107 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5108 wasn't able to compile compile on an IRIX 5 system.
5110 * Added execute permission to gdb/gdbserver/configure
5112 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5113 permission. This bug would cause configure to fail on a number of
5114 systems (Solaris, IRIX). Ref: server/519.
5116 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5118 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5119 has been updated to use constant array sizes.
5121 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5123 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5124 its generated DWARF Call Frame Info. This encoding was causing GDB to
5125 panic, that panic has been fixed. Ref: gdb/1628.
5127 * Fixed a problem when examining parameters in shared library code.
5129 When examining parameters in optimized shared library code generated
5130 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5131 not available''. GDB now correctly displays the variable's value.
5133 *** Changes in GDB 6.1:
5135 * Removed --with-mmalloc
5137 Support for the mmalloc memory manager has been removed, as it
5138 conflicted with the internal gdb byte cache.
5140 * Changes in AMD64 configurations
5142 The AMD64 target now includes the %cs and %ss registers. As a result
5143 the AMD64 remote protocol has changed; this affects the floating-point
5144 and SSE registers. If you rely on those registers for your debugging,
5145 you should upgrade gdbserver on the remote side.
5147 * Revised SPARC target
5149 The SPARC target has been completely revised, incorporating the
5150 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5151 support for LynxOS and SunOS 4 has been dropped. Calling functions
5152 from within GDB on operating systems with a non-executable stack
5153 (Solaris, OpenBSD) now works.
5157 GDB has a new C++ demangler which does a better job on the mangled
5158 names generated by current versions of g++. It also runs faster, so
5159 with this and other changes gdb should now start faster on large C++
5162 * DWARF 2 Location Expressions
5164 GDB support for location expressions has been extended to support function
5165 arguments and frame bases. Older versions of GDB could crash when they
5168 * C++ nested types and namespaces
5170 GDB's support for nested types and namespaces in C++ has been
5171 improved, especially if you use the DWARF 2 debugging format. (This
5172 is the default for recent versions of GCC on most platforms.)
5173 Specifically, if you have a class "Inner" defined within a class or
5174 namespace "Outer", then GDB realizes that the class's name is
5175 "Outer::Inner", not simply "Inner". This should greatly reduce the
5176 frequency of complaints about not finding RTTI symbols. In addition,
5177 if you are stopped at inside of a function defined within a namespace,
5178 GDB modifies its name lookup accordingly.
5180 * New native configurations
5182 NetBSD/amd64 x86_64-*-netbsd*
5183 OpenBSD/amd64 x86_64-*-openbsd*
5184 OpenBSD/alpha alpha*-*-openbsd*
5185 OpenBSD/sparc sparc-*-openbsd*
5186 OpenBSD/sparc64 sparc64-*-openbsd*
5188 * New debugging protocols
5190 M32R with SDI protocol m32r-*-elf*
5192 * "set prompt-escape-char" command deleted.
5194 The command "set prompt-escape-char" has been deleted. This command,
5195 and its very obscure effet on GDB's prompt, was never documented,
5196 tested, nor mentioned in the NEWS file.
5198 * OBSOLETE configurations and files
5200 Configurations that have been declared obsolete in this release have
5201 been commented out. Unless there is activity to revive these
5202 configurations, the next release of GDB will have their sources
5203 permanently REMOVED.
5205 Sun 3, running SunOS 3 m68*-*-sunos3*
5206 Sun 3, running SunOS 4 m68*-*-sunos4*
5207 Sun 2, running SunOS 3 m68000-*-sunos3*
5208 Sun 2, running SunOS 4 m68000-*-sunos4*
5209 Motorola 680x0 running LynxOS m68*-*-lynxos*
5210 AT&T 3b1/Unix pc m68*-att-*
5211 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5212 decstation mips-dec-* mips-little-*
5213 riscos mips-*-riscos* mips-*-sysv*
5214 sonymips mips-sony-*
5215 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5217 * REMOVED configurations and files
5219 SGI Irix-4.x mips-sgi-irix4 or iris4
5220 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5221 Z8000 simulator z8k-zilog-none or z8ksim
5222 Matsushita MN10200 w/simulator mn10200-*-*
5223 H8/500 simulator h8500-hitachi-hms or h8500hms
5224 HP/PA running BSD hppa*-*-bsd*
5225 HP/PA running OSF/1 hppa*-*-osf*
5226 HP/PA Pro target hppa*-*-pro*
5227 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5228 386BSD i[3456]86-*-bsd*
5229 Sequent family i[3456]86-sequent-sysv4*
5230 i[3456]86-sequent-sysv*
5231 i[3456]86-sequent-bsd*
5232 SPARC running LynxOS sparc-*-lynxos*
5233 SPARC running SunOS 4 sparc-*-sunos4*
5234 Tsqware Sparclet sparclet-*-*
5235 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5237 *** Changes in GDB 6.0:
5241 Support for debugging the Objective-C programming language has been
5242 integrated into GDB.
5244 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5246 DWARF 2's Call Frame Information makes available compiler generated
5247 information that more exactly describes the program's run-time stack.
5248 By using this information, GDB is able to provide more robust stack
5251 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5252 have been updated to use a new backtrace mechanism which includes
5253 DWARF 2 CFI support.
5257 GDB's remote protocol has been extended to include support for hosted
5258 file I/O (where the remote target uses GDB's file system). See GDB's
5259 remote protocol documentation for details.
5261 * All targets using the new architecture framework.
5263 All of GDB's targets have been updated to use the new internal
5264 architecture framework. The way is now open for future GDB releases
5265 to include cross-architecture native debugging support (i386 on amd64,
5268 * GNU/Linux's Thread Local Storage (TLS)
5270 GDB now includes support for for the GNU/Linux implementation of
5271 per-thread variables.
5273 * GNU/Linux's Native POSIX Thread Library (NPTL)
5275 GDB's thread code has been updated to work with either the new
5276 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5278 * Separate debug info.
5280 GDB, in conjunction with BINUTILS, now supports a mechanism for
5281 automatically loading debug information from a separate file. Instead
5282 of shipping full debug and non-debug versions of system libraries,
5283 system integrators can now instead ship just the stripped libraries
5284 and optional debug files.
5286 * DWARF 2 Location Expressions
5288 DWARF 2 Location Expressions allow the compiler to more completely
5289 describe the location of variables (even in optimized code) to the
5292 GDB now includes preliminary support for location expressions (support
5293 for DW_OP_piece is still missing).
5297 A number of long standing bugs that caused GDB to die while starting a
5298 Java application have been fixed. GDB's Java support is now
5299 considered "useable".
5301 * GNU/Linux support for fork, vfork, and exec.
5303 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5304 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5307 * GDB supports logging output to a file
5309 There are two new commands, "set logging" and "show logging", which can be
5310 used to capture GDB's output to a file.
5312 * The meaning of "detach" has changed for gdbserver
5314 The "detach" command will now resume the application, as documented. To
5315 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5318 * d10v, m68hc11 `regs' command deprecated
5320 The `info registers' command has been updated so that it displays the
5321 registers using a format identical to the old `regs' command.
5325 A new command, "maint set profile on/off", has been added. This command can
5326 be used to enable or disable profiling while running GDB, to profile a
5327 session or a set of commands. In addition there is a new configure switch,
5328 "--enable-profiling", which will cause GDB to be compiled with profiling
5329 data, for more informative profiling results.
5331 * Default MI syntax changed to "mi2".
5333 The default MI (machine interface) syntax, enabled by the command line
5334 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5335 "mi1", can be enabled by specifying the option "-i=mi1".
5337 Support for the original "mi0" syntax (included in GDB 5.0) has been
5340 Fix for gdb/192: removed extraneous space when displaying frame level.
5341 Fix for gdb/672: update changelist is now output in mi list format.
5342 Fix for gdb/702: a -var-assign that updates the value now shows up
5343 in a subsequent -var-update.
5345 * New native configurations.
5347 FreeBSD/amd64 x86_64-*-freebsd*
5349 * Multi-arched targets.
5351 HP/PA HPUX11 hppa*-*-hpux*
5352 Renesas M32R/D w/simulator m32r-*-elf*
5354 * OBSOLETE configurations and files
5356 Configurations that have been declared obsolete in this release have
5357 been commented out. Unless there is activity to revive these
5358 configurations, the next release of GDB will have their sources
5359 permanently REMOVED.
5361 Z8000 simulator z8k-zilog-none or z8ksim
5362 Matsushita MN10200 w/simulator mn10200-*-*
5363 H8/500 simulator h8500-hitachi-hms or h8500hms
5364 HP/PA running BSD hppa*-*-bsd*
5365 HP/PA running OSF/1 hppa*-*-osf*
5366 HP/PA Pro target hppa*-*-pro*
5367 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5368 Sequent family i[3456]86-sequent-sysv4*
5369 i[3456]86-sequent-sysv*
5370 i[3456]86-sequent-bsd*
5371 Tsqware Sparclet sparclet-*-*
5372 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5374 * REMOVED configurations and files
5377 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5378 IBM AIX PS/2 i[3456]86-*-aix
5379 i386 running Mach 3.0 i[3456]86-*-mach3*
5380 i386 running Mach i[3456]86-*-mach*
5381 i386 running OSF/1 i[3456]86-*osf1mk*
5382 HP/Apollo 68k Family m68*-apollo*-sysv*,
5384 m68*-hp-bsd*, m68*-hp-hpux*
5385 Argonaut Risc Chip (ARC) arc-*-*
5386 Mitsubishi D30V d30v-*-*
5387 Fujitsu FR30 fr30-*-elf*
5388 OS/9000 i[34]86-*-os9k
5389 I960 with MON960 i960-*-coff
5391 * MIPS $fp behavior changed
5393 The convenience variable $fp, for the MIPS, now consistently returns
5394 the address of the current frame's base. Previously, depending on the
5395 context, $fp could refer to either $sp or the current frame's base
5396 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5397 The GNU Source-Level Debugger''.
5399 *** Changes in GDB 5.3:
5401 * GNU/Linux shared library multi-threaded performance improved.
5403 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5404 `/proc', in preference to `ptrace' for memory reads. This may result
5405 in an improvement in the start-up time of multi-threaded, shared
5406 library applications when run under GDB. One GDB user writes: ``loads
5407 shared libs like mad''.
5409 * ``gdbserver'' now supports multi-threaded applications on some targets
5411 Support for debugging multi-threaded applications which use
5412 the GNU/Linux LinuxThreads package has been added for
5413 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5414 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5416 * GDB now supports C/C++ preprocessor macros.
5418 GDB now expands preprocessor macro invocations in C/C++ expressions,
5419 and provides various commands for showing macro definitions and how
5422 The new command `macro expand EXPRESSION' expands any macro
5423 invocations in expression, and shows the result.
5425 The new command `show macro MACRO-NAME' shows the definition of the
5426 macro named MACRO-NAME, and where it was defined.
5428 Most compilers don't include information about macros in the debugging
5429 information by default. In GCC 3.1, for example, you need to compile
5430 your program with the options `-gdwarf-2 -g3'. If the macro
5431 information is present in the executable, GDB will read it.
5433 * Multi-arched targets.
5435 DEC Alpha (partial) alpha*-*-*
5436 DEC VAX (partial) vax-*-*
5438 National Semiconductor NS32000 (partial) ns32k-*-*
5439 Motorola 68000 (partial) m68k-*-*
5440 Motorola MCORE mcore-*-*
5444 Fujitsu FRV architecture added by Red Hat frv*-*-*
5447 * New native configurations
5449 Alpha NetBSD alpha*-*-netbsd*
5450 SH NetBSD sh*-*-netbsdelf*
5451 MIPS NetBSD mips*-*-netbsd*
5452 UltraSPARC NetBSD sparc64-*-netbsd*
5454 * OBSOLETE configurations and files
5456 Configurations that have been declared obsolete in this release have
5457 been commented out. Unless there is activity to revive these
5458 configurations, the next release of GDB will have their sources
5459 permanently REMOVED.
5461 Mitsubishi D30V d30v-*-*
5462 OS/9000 i[34]86-*-os9k
5463 IBM AIX PS/2 i[3456]86-*-aix
5464 Fujitsu FR30 fr30-*-elf*
5465 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5466 Argonaut Risc Chip (ARC) arc-*-*
5467 i386 running Mach 3.0 i[3456]86-*-mach3*
5468 i386 running Mach i[3456]86-*-mach*
5469 i386 running OSF/1 i[3456]86-*osf1mk*
5470 HP/Apollo 68k Family m68*-apollo*-sysv*,
5472 m68*-hp-bsd*, m68*-hp-hpux*
5473 I960 with MON960 i960-*-coff
5475 * OBSOLETE languages
5477 CHILL, a Pascal like language used by telecommunications companies.
5479 * REMOVED configurations and files
5481 AMD 29k family via UDI a29k-amd-udi, udi29k
5482 A29K VxWorks a29k-*-vxworks
5483 AMD 29000 embedded, using EBMON a29k-none-none
5484 AMD 29000 embedded with COFF a29k-none-coff
5485 AMD 29000 embedded with a.out a29k-none-aout
5487 testsuite/gdb.hp/gdb.threads-hp/ directory
5489 * New command "set max-user-call-depth <nnn>"
5491 This command allows the user to limit the call depth of user-defined
5492 commands. The default is 1024.
5494 * Changes in FreeBSD/i386 native debugging.
5496 Support for the "generate-core-file" has been added.
5498 * New commands "dump", "append", and "restore".
5500 These commands allow data to be copied from target memory
5501 to a bfd-format or binary file (dump and append), and back
5502 from a file into memory (restore).
5504 * Improved "next/step" support on multi-processor Alpha Tru64.
5506 The previous single-step mechanism could cause unpredictable problems,
5507 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5508 of a software single-step mechanism prevents this.
5510 *** Changes in GDB 5.2.1:
5518 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5519 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5520 Fix, by Joel Brobecker imported from mainline.
5522 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5523 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5524 Fix, by Fred Fish, imported from mainline.
5526 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5527 Surprisingly enough, it works now.
5528 By Michal Ludvig, imported from mainline.
5530 i386 hardware watchpoint support:
5531 avoid misses on second run for some targets.
5532 By Pierre Muller, imported from mainline.
5534 *** Changes in GDB 5.2:
5536 * New command "set trust-readonly-sections on[off]".
5538 This command is a hint that tells gdb that read-only sections
5539 really are read-only (ie. that their contents will not change).
5540 In this mode, gdb will go to the object file rather than the
5541 target to read memory from read-only sections (such as ".text").
5542 This can be a significant performance improvement on some
5543 (notably embedded) targets.
5545 * New command "generate-core-file" (or "gcore").
5547 This new gdb command allows the user to drop a core file of the child
5548 process state at any time. So far it's been implemented only for
5549 GNU/Linux and Solaris, but should be relatively easily ported to other
5550 hosts. Argument is core file name (defaults to core.<pid>).
5552 * New command line option
5554 GDB now accepts --pid or -p followed by a process id.
5556 * Change in command line behavior -- corefiles vs. process ids.
5558 There is a subtle behavior in the way in which GDB handles
5559 command line arguments. The first non-flag argument is always
5560 a program to debug, but the second non-flag argument may either
5561 be a corefile or a process id. Previously, GDB would attempt to
5562 open the second argument as a corefile, and if that failed, would
5563 issue a superfluous error message and then attempt to attach it as
5564 a process. Now, if the second argument begins with a non-digit,
5565 it will be treated as a corefile. If it begins with a digit,
5566 GDB will attempt to attach it as a process, and if no such process
5567 is found, will then attempt to open it as a corefile.
5569 * Changes in ARM configurations.
5571 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5572 configuration is fully multi-arch.
5574 * New native configurations
5576 ARM NetBSD arm*-*-netbsd*
5577 x86 OpenBSD i[3456]86-*-openbsd*
5578 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5579 Sparc64 running FreeBSD sparc64-*-freebsd*
5583 Sanyo XStormy16 xstormy16-elf
5585 * OBSOLETE configurations and files
5587 Configurations that have been declared obsolete in this release have
5588 been commented out. Unless there is activity to revive these
5589 configurations, the next release of GDB will have their sources
5590 permanently REMOVED.
5592 AMD 29k family via UDI a29k-amd-udi, udi29k
5593 A29K VxWorks a29k-*-vxworks
5594 AMD 29000 embedded, using EBMON a29k-none-none
5595 AMD 29000 embedded with COFF a29k-none-coff
5596 AMD 29000 embedded with a.out a29k-none-aout
5598 testsuite/gdb.hp/gdb.threads-hp/ directory
5600 * REMOVED configurations and files
5602 TI TMS320C80 tic80-*-*
5604 PowerPC Solaris powerpcle-*-solaris*
5605 PowerPC Windows NT powerpcle-*-cygwin32
5606 PowerPC Netware powerpc-*-netware*
5607 Harris/CXUX m88k m88*-harris-cxux*
5608 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5609 ns32k-utek-sysv* ns32k-utek-*
5610 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5611 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5612 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5613 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5614 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5616 * Changes to command line processing
5618 The new `--args' feature can be used to specify command-line arguments
5619 for the inferior from gdb's command line.
5621 * Changes to key bindings
5623 There is a new `operate-and-get-next' function bound to `C-o'.
5625 *** Changes in GDB 5.1.1
5627 Fix compile problem on DJGPP.
5629 Fix a problem with floating-point registers on the i386 being
5632 Fix to stop GDB crashing on .debug_str debug info.
5634 Numerous documentation fixes.
5636 Numerous testsuite fixes.
5638 *** Changes in GDB 5.1:
5640 * New native configurations
5642 Alpha FreeBSD alpha*-*-freebsd*
5643 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5644 MIPS GNU/Linux mips*-*-linux*
5645 MIPS SGI Irix 6.x mips*-sgi-irix6*
5646 ia64 AIX ia64-*-aix*
5647 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5651 Motorola 68HC11 and 68HC12 m68hc11-elf
5653 UltraSparc running GNU/Linux sparc64-*-linux*
5655 * OBSOLETE configurations and files
5657 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5658 Harris/CXUX m88k m88*-harris-cxux*
5659 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5660 ns32k-utek-sysv* ns32k-utek-*
5661 TI TMS320C80 tic80-*-*
5663 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5664 PowerPC Solaris powerpcle-*-solaris*
5665 PowerPC Windows NT powerpcle-*-cygwin32
5666 PowerPC Netware powerpc-*-netware*
5667 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5668 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5669 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5670 Apple Macintosh (MPW) host N/A
5672 stuff.c (Program to stuff files into a specially prepared space in kdb)
5673 kdb-start.c (Main loop for the standalone kernel debugger)
5675 Configurations that have been declared obsolete in this release have
5676 been commented out. Unless there is activity to revive these
5677 configurations, the next release of GDB will have their sources
5678 permanently REMOVED.
5680 * REMOVED configurations and files
5682 Altos 3068 m68*-altos-*
5683 Convex c1-*-*, c2-*-*
5685 ARM RISCix arm-*-* (as host)
5689 * GDB has been converted to ISO C.
5691 GDB's source code has been converted to ISO C. In particular, the
5692 sources are fully protoized, and rely on standard headers being
5697 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5699 * The MI enabled by default.
5701 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5702 revised and enabled by default. Packages which use GDB as a debugging
5703 engine behind a UI or another front end are encouraged to switch to
5704 using the GDB/MI interface, instead of the old annotations interface
5705 which is now deprecated.
5707 * Support for debugging Pascal programs.
5709 GDB now includes support for debugging Pascal programs. The following
5710 main features are supported:
5712 - Pascal-specific data types such as sets;
5714 - automatic recognition of Pascal sources based on file-name
5717 - Pascal-style display of data types, variables, and functions;
5719 - a Pascal expression parser.
5721 However, some important features are not yet supported.
5723 - Pascal string operations are not supported at all;
5725 - there are some problems with boolean types;
5727 - Pascal type hexadecimal constants are not supported
5728 because they conflict with the internal variables format;
5730 - support for Pascal objects and classes is not full yet;
5732 - unlike Pascal, GDB is case-sensitive for symbol names.
5734 * Changes in completion.
5736 Commands such as `shell', `run' and `set args', which pass arguments
5737 to inferior programs, now complete on file names, similar to what
5738 users expect at the shell prompt.
5740 Commands which accept locations, such as `disassemble', `print',
5741 `breakpoint', `until', etc. now complete on filenames as well as
5742 program symbols. Thus, if you type "break foob TAB", and the source
5743 files linked into the programs include `foobar.c', that file name will
5744 be one of the candidates for completion. However, file names are not
5745 considered for completion after you typed a colon that delimits a file
5746 name from a name of a function in that file, as in "break foo.c:bar".
5748 `set demangle-style' completes on available demangling styles.
5750 * New platform-independent commands:
5752 It is now possible to define a post-hook for a command as well as a
5753 hook that runs before the command. For more details, see the
5754 documentation of `hookpost' in the GDB manual.
5756 * Changes in GNU/Linux native debugging.
5758 Support for debugging multi-threaded programs has been completely
5759 revised for all platforms except m68k and sparc. You can now debug as
5760 many threads as your system allows you to have.
5762 Attach/detach is supported for multi-threaded programs.
5764 Support for SSE registers was added for x86. This doesn't work for
5765 multi-threaded programs though.
5767 * Changes in MIPS configurations.
5769 Multi-arch support is enabled for all MIPS configurations.
5771 GDB can now be built as native debugger on SGI Irix 6.x systems for
5772 debugging n32 executables. (Debugging 64-bit executables is not yet
5775 * Unified support for hardware watchpoints in all x86 configurations.
5777 Most (if not all) native x86 configurations support hardware-assisted
5778 breakpoints and watchpoints in a unified manner. This support
5779 implements debug register sharing between watchpoints, which allows to
5780 put a virtually infinite number of watchpoints on the same address,
5781 and also supports watching regions up to 16 bytes with several debug
5784 The new maintenance command `maintenance show-debug-regs' toggles
5785 debugging print-outs in functions that insert, remove, and test
5786 watchpoints and hardware breakpoints.
5788 * Changes in the DJGPP native configuration.
5790 New command ``info dos sysinfo'' displays assorted information about
5791 the CPU, OS, memory, and DPMI server.
5793 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5794 display information about segment descriptors stored in GDT, LDT, and
5797 New commands ``info dos pde'' and ``info dos pte'' display entries
5798 from Page Directory and Page Tables (for now works with CWSDPMI only).
5799 New command ``info dos address-pte'' displays the Page Table entry for
5800 a given linear address.
5802 GDB can now pass command lines longer than 126 characters to the
5803 program being debugged (requires an update to the libdbg.a library
5804 which is part of the DJGPP development kit).
5806 DWARF2 debug info is now supported.
5808 It is now possible to `step' and `next' through calls to `longjmp'.
5810 * Changes in documentation.
5812 All GDB documentation was converted to GFDL, the GNU Free
5813 Documentation License.
5815 Tracepoints-related commands are now fully documented in the GDB
5818 TUI, the Text-mode User Interface, is now documented in the manual.
5820 Tracepoints-related commands are now fully documented in the GDB
5823 The "GDB Internals" manual now has an index. It also includes
5824 documentation of `ui_out' functions, GDB coding standards, x86
5825 hardware watchpoints, and memory region attributes.
5827 * GDB's version number moved to ``version.in''
5829 The Makefile variable VERSION has been replaced by the file
5830 ``version.in''. People creating GDB distributions should update the
5831 contents of this file.
5835 GUD support is now a standard part of the EMACS distribution.
5837 *** Changes in GDB 5.0:
5839 * Improved support for debugging FP programs on x86 targets
5841 Unified and much-improved support for debugging floating-point
5842 programs on all x86 targets. In particular, ``info float'' now
5843 displays the FP registers in the same format on all x86 targets, with
5844 greater level of detail.
5846 * Improvements and bugfixes in hardware-assisted watchpoints
5848 It is now possible to watch array elements, struct members, and
5849 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5850 on x86 targets no longer erroneously trigger when the address is
5853 * Improvements in the native DJGPP version of GDB
5855 The distribution now includes all the scripts and auxiliary files
5856 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5857 machines ``out of the box''.
5859 The DJGPP version can now debug programs that use signals. It is
5860 possible to catch signals that happened in the debuggee, deliver
5861 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5862 would kill the program being debugged.) Programs that hook hardware
5863 interrupts (keyboard, timer, etc.) can also be debugged.
5865 It is now possible to debug DJGPP programs that redirect their
5866 standard handles or switch them to raw (as opposed to cooked) mode, or
5867 even close them. The command ``run < foo > bar'' works as expected,
5868 and ``info terminal'' reports useful information about the debuggee's
5869 terminal, including raw/cooked mode, redirection, etc.
5871 The DJGPP version now uses termios functions for console I/O, which
5872 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5875 DOS-style file names with drive letters are now fully supported by
5878 It is now possible to debug DJGPP programs that switch their working
5879 directory. It is also possible to rerun the debuggee any number of
5880 times without restarting GDB; thus, you can use the same setup,
5881 breakpoints, etc. for many debugging sessions.
5883 * New native configurations
5885 ARM GNU/Linux arm*-*-linux*
5886 PowerPC GNU/Linux powerpc-*-linux*
5890 Motorola MCore mcore-*-*
5891 x86 VxWorks i[3456]86-*-vxworks*
5892 PowerPC VxWorks powerpc-*-vxworks*
5893 TI TMS320C80 tic80-*-*
5895 * OBSOLETE configurations
5897 Altos 3068 m68*-altos-*
5898 Convex c1-*-*, c2-*-*
5900 ARM RISCix arm-*-* (as host)
5903 Configurations that have been declared obsolete will be commented out,
5904 but the code will be left in place. If there is no activity to revive
5905 these configurations before the next release of GDB, the sources will
5906 be permanently REMOVED.
5908 * Gould support removed
5910 Support for the Gould PowerNode and NP1 has been removed.
5912 * New features for SVR4
5914 On SVR4 native platforms (such as Solaris), if you attach to a process
5915 without first loading a symbol file, GDB will now attempt to locate and
5916 load symbols from the running process's executable file.
5918 * Many C++ enhancements
5920 C++ support has been greatly improved. Overload resolution now works properly
5921 in almost all cases. RTTI support is on the way.
5923 * Remote targets can connect to a sub-program
5925 A popen(3) style serial-device has been added. This device starts a
5926 sub-process (such as a stand-alone simulator) and then communicates
5927 with that. The sub-program to run is specified using the syntax
5928 ``|<program> <args>'' vis:
5930 (gdb) set remotedebug 1
5931 (gdb) target extended-remote |mn10300-elf-sim program-args
5933 * MIPS 64 remote protocol
5935 A long standing bug in the mips64 remote protocol where by GDB
5936 expected certain 32 bit registers (ex SR) to be transfered as 32
5937 instead of 64 bits has been fixed.
5939 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5940 added to provide backward compatibility with older versions of GDB.
5942 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5944 The command ``set remotebinarydownload'' command has been replaced by
5945 ``set remote X-packet''. Other commands in ``set remote'' family
5946 include ``set remote P-packet''.
5948 * Breakpoint commands accept ranges.
5950 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5951 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5952 ``tracepoint passcount'' also accepts a range of tracepoints.
5954 * ``apropos'' command added.
5956 The ``apropos'' command searches through command names and
5957 documentation strings, printing out matches, making it much easier to
5958 try to find a command that does what you are looking for.
5962 A new machine oriented interface (MI) has been added to GDB. This
5963 interface is designed for debug environments running GDB as a separate
5964 process. This is part of the long term libGDB project. See the
5965 "GDB/MI" chapter of the GDB manual for further information. It can be
5966 enabled by configuring with:
5968 .../configure --enable-gdbmi
5970 *** Changes in GDB-4.18:
5972 * New native configurations
5974 HP-UX 10.20 hppa*-*-hpux10.20
5975 HP-UX 11.x hppa*-*-hpux11.0*
5976 M68K GNU/Linux m68*-*-linux*
5980 Fujitsu FR30 fr30-*-elf*
5981 Intel StrongARM strongarm-*-*
5982 Mitsubishi D30V d30v-*-*
5984 * OBSOLETE configurations
5986 Gould PowerNode, NP1 np1-*-*, pn-*-*
5988 Configurations that have been declared obsolete will be commented out,
5989 but the code will be left in place. If there is no activity to revive
5990 these configurations before the next release of GDB, the sources will
5991 be permanently REMOVED.
5995 As a compatibility experiment, GDB's source files buildsym.h and
5996 buildsym.c have been converted to pure standard C, no longer
5997 containing any K&R compatibility code. We believe that all systems in
5998 use today either come with a standard C compiler, or have a GCC port
5999 available. If this is not true, please report the affected
6000 configuration to bug-gdb@gnu.org immediately. See the README file for
6001 information about getting a standard C compiler if you don't have one
6006 GDB now uses readline 2.2.
6008 * set extension-language
6010 You can now control the mapping between filename extensions and source
6011 languages by using the `set extension-language' command. For instance,
6012 you can ask GDB to treat .c files as C++ by saying
6013 set extension-language .c c++
6014 The command `info extensions' lists all of the recognized extensions
6015 and their associated languages.
6017 * Setting processor type for PowerPC and RS/6000
6019 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6020 you can use the `set processor' command to specify what variant of the
6021 PowerPC family you are debugging. The command
6025 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6026 following PowerPC and RS6000 variants:
6028 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6029 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6031 403GC IBM PowerPC 403GC
6032 505 Motorola PowerPC 505
6033 860 Motorola PowerPC 860 or 850
6034 601 Motorola PowerPC 601
6035 602 Motorola PowerPC 602
6036 603 Motorola/IBM PowerPC 603 or 603e
6037 604 Motorola PowerPC 604 or 604e
6038 750 Motorola/IBM PowerPC 750 or 750
6040 At the moment, this command just tells GDB what to name the
6041 special-purpose processor registers. Since almost all the affected
6042 registers are inaccessible to user-level programs, this command is
6043 only useful for remote debugging in its present form.
6047 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6048 more extensive support for HP-UX. Added features include shared
6049 library support, kernel threads and hardware watchpoints for 11.00,
6050 support for HP's ANSI C and C++ compilers, and a compatibility mode
6051 for xdb and dbx commands.
6055 HP's donation includes the new concept of catchpoints, which is a
6056 generalization of the old catch command. On HP-UX, it is now possible
6057 to catch exec, fork, and vfork, as well as library loading.
6059 This means that the existing catch command has changed; its first
6060 argument now specifies the type of catch to be set up. See the
6061 output of "help catch" for a list of catchpoint types.
6063 * Debugging across forks
6065 On HP-UX, you can choose which process to debug when a fork() happens
6070 HP has donated a curses-based terminal user interface (TUI). To get
6071 it, build with --enable-tui. Although this can be enabled for any
6072 configuration, at present it only works for native HP debugging.
6074 * GDB remote protocol additions
6076 A new protocol packet 'X' that writes binary data is now available.
6077 Default behavior is to try 'X', then drop back to 'M' if the stub
6078 fails to respond. The settable variable `remotebinarydownload'
6079 allows explicit control over the use of 'X'.
6081 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6082 full 64-bit address. The command
6084 set remoteaddresssize 32
6086 can be used to revert to the old behaviour. For existing remote stubs
6087 the change should not be noticed, as the additional address information
6090 In order to assist in debugging stubs, you may use the maintenance
6091 command `packet' to send any text string to the stub. For instance,
6093 maint packet heythere
6095 sends the packet "$heythere#<checksum>". Note that it is very easy to
6096 disrupt a debugging session by sending the wrong packet at the wrong
6099 The compare-sections command allows you to compare section data on the
6100 target to what is in the executable file without uploading or
6101 downloading, by comparing CRC checksums.
6103 * Tracing can collect general expressions
6105 You may now collect general expressions at tracepoints. This requires
6106 further additions to the target-side stub; see tracepoint.c and
6107 doc/agentexpr.texi for further details.
6109 * mask-address variable for Mips
6111 For Mips targets, you may control the zeroing of the upper 32 bits of
6112 a 64-bit address by entering `set mask-address on'. This is mainly
6113 of interest to users of embedded R4xxx and R5xxx processors.
6115 * Higher serial baud rates
6117 GDB's serial code now allows you to specify baud rates 57600, 115200,
6118 230400, and 460800 baud. (Note that your host system may not be able
6119 to achieve all of these rates.)
6123 The i960 configuration now includes an initial implementation of a
6124 builtin simulator, contributed by Jim Wilson.
6127 *** Changes in GDB-4.17:
6129 * New native configurations
6131 Alpha GNU/Linux alpha*-*-linux*
6132 Unixware 2.x i[3456]86-unixware2*
6133 Irix 6.x mips*-sgi-irix6*
6134 PowerPC GNU/Linux powerpc-*-linux*
6135 PowerPC Solaris powerpcle-*-solaris*
6136 Sparc GNU/Linux sparc-*-linux*
6137 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6141 Argonaut Risc Chip (ARC) arc-*-*
6142 Hitachi H8/300S h8300*-*-*
6143 Matsushita MN10200 w/simulator mn10200-*-*
6144 Matsushita MN10300 w/simulator mn10300-*-*
6145 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6146 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6147 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6148 Mitsubishi D10V w/simulator d10v-*-*
6149 Mitsubishi M32R/D w/simulator m32r-*-elf*
6150 Tsqware Sparclet sparclet-*-*
6151 NEC V850 w/simulator v850-*-*
6153 * New debugging protocols
6155 ARM with RDI protocol arm*-*-*
6156 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6157 DDB and LSI variants of PMON protocol mips*-*-*
6158 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6159 PowerPC with SDS protocol powerpc{,le}-*-eabi
6160 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6164 All configurations can now understand and use the DWARF 2 debugging
6165 format. The choice is automatic, if the symbol file contains DWARF 2
6170 GDB now includes basic Java language support. This support is
6171 only useful with Java compilers that produce native machine code.
6173 * solib-absolute-prefix and solib-search-path
6175 For SunOS and SVR4 shared libraries, you may now set the prefix for
6176 loading absolute shared library symbol files, and the search path for
6177 locating non-absolute shared library symbol files.
6179 * Live range splitting
6181 GDB can now effectively debug code for which GCC has performed live
6182 range splitting as part of its optimization. See gdb/doc/LRS for
6183 more details on the expected format of the stabs information.
6187 GDB's support for the GNU Hurd, including thread debugging, has been
6188 updated to work with current versions of the Hurd.
6192 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6193 instruction set. ARM GDB automatically detects when Thumb
6194 instructions are in use, and adjusts disassembly and backtracing
6199 GDB's MIPS target configurations now handle the MIP16 16-bit
6204 GDB now includes support for overlays; if an executable has been
6205 linked such that multiple sections are based at the same address, GDB
6206 will decide which section to use for symbolic info. You can choose to
6207 control the decision manually, using overlay commands, or implement
6208 additional target-side support and use "overlay load-target" to bring
6209 in the overlay mapping. Do "help overlay" for more detail.
6213 The command "info symbol <address>" displays information about
6214 the symbol at the specified address.
6218 The standard remote protocol now includes an extension that allows
6219 asynchronous collection and display of trace data. This requires
6220 extensive support in the target-side debugging stub. Tracing mode
6221 includes a new interaction mode in GDB and new commands: see the
6222 file tracepoint.c for more details.
6226 Configurations for embedded MIPS now include a simulator contributed
6227 by Cygnus Solutions. The simulator supports the instruction sets
6228 of most MIPS variants.
6232 Sparc configurations may now include the ERC32 simulator contributed
6233 by the European Space Agency. The simulator is not built into
6234 Sparc targets by default; configure with --enable-sim to include it.
6238 For target configurations that may include multiple variants of a
6239 basic architecture (such as MIPS and SH), you may now set the
6240 architecture explicitly. "set arch" sets, "info arch" lists
6241 the possible architectures.
6243 *** Changes in GDB-4.16:
6245 * New native configurations
6247 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6248 M68K NetBSD m68k-*-netbsd*
6249 PowerPC AIX 4.x powerpc-*-aix*
6250 PowerPC MacOS powerpc-*-macos*
6251 PowerPC Windows NT powerpcle-*-cygwin32
6252 RS/6000 AIX 4.x rs6000-*-aix4*
6256 ARM with RDP protocol arm-*-*
6257 I960 with MON960 i960-*-coff
6258 MIPS VxWorks mips*-*-vxworks*
6259 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6260 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6262 Matra Sparclet sparclet-*-*
6266 The powerpc-eabi configuration now includes the PSIM simulator,
6267 contributed by Andrew Cagney, with assistance from Mike Meissner.
6268 PSIM is a very elaborate model of the PowerPC, including not only
6269 basic instruction set execution, but also details of execution unit
6270 performance and I/O hardware. See sim/ppc/README for more details.
6274 GDB now works with Solaris 2.5.
6276 * Windows 95/NT native
6278 GDB will now work as a native debugger on Windows 95 and Windows NT.
6279 To build it from source, you must use the "gnu-win32" environment,
6280 which uses a DLL to emulate enough of Unix to run the GNU tools.
6281 Further information, binaries, and sources are available at
6282 ftp.cygnus.com, under pub/gnu-win32.
6284 * dont-repeat command
6286 If a user-defined command includes the command `dont-repeat', then the
6287 command will not be repeated if the user just types return. This is
6288 useful if the command is time-consuming to run, so that accidental
6289 extra keystrokes don't run the same command many times.
6291 * Send break instead of ^C
6293 The standard remote protocol now includes an option to send a break
6294 rather than a ^C to the target in order to interrupt it. By default,
6295 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6297 * Remote protocol timeout
6299 The standard remote protocol includes a new variable `remotetimeout'
6300 that allows you to set the number of seconds before GDB gives up trying
6301 to read from the target. The default value is 2.
6303 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6305 By default GDB will automatically keep track of objects as they are
6306 loaded and unloaded by the dynamic linker. By using the command `set
6307 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6308 when shared library events occur, thus allowing you to set breakpoints
6309 in shared libraries which are explicitly loaded by the inferior.
6311 Note this feature does not work on hpux8. On hpux9 you must link
6312 /usr/lib/end.o into your program. This feature should work
6313 automatically on hpux10.
6315 * Irix 5.x hardware watchpoint support
6317 Irix 5 configurations now support the use of hardware watchpoints.
6319 * Mips protocol "SYN garbage limit"
6321 When debugging a Mips target using the `target mips' protocol, you
6322 may set the number of characters that GDB will ignore by setting
6323 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6324 every character. The default value is 1050.
6326 * Recording and replaying remote debug sessions
6328 If you set `remotelogfile' to the name of a file, gdb will write to it
6329 a recording of a remote debug session. This recording may then be
6330 replayed back to gdb using "gdbreplay". See gdbserver/README for
6331 details. This is useful when you have a problem with GDB while doing
6332 remote debugging; you can make a recording of the session and send it
6333 to someone else, who can then recreate the problem.
6335 * Speedups for remote debugging
6337 GDB includes speedups for downloading and stepping MIPS systems using
6338 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6339 and more efficient S-record downloading.
6341 * Memory use reductions and statistics collection
6343 GDB now uses less memory and reports statistics about memory usage.
6344 Try the `maint print statistics' command, for example.
6346 *** Changes in GDB-4.15:
6348 * Psymtabs for XCOFF
6350 The symbol reader for AIX GDB now uses partial symbol tables. This
6351 can greatly improve startup time, especially for large executables.
6353 * Remote targets use caching
6355 Remote targets now use a data cache to speed up communication with the
6356 remote side. The data cache could lead to incorrect results because
6357 it doesn't know about volatile variables, thus making it impossible to
6358 debug targets which use memory mapped I/O devices. `set remotecache
6359 off' turns the the data cache off.
6361 * Remote targets may have threads
6363 The standard remote protocol now includes support for multiple threads
6364 in the target system, using new protocol commands 'H' and 'T'. See
6365 gdb/remote.c for details.
6369 If GDB is configured with `--enable-netrom', then it will include
6370 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6371 acts as though it is a bank of ROM on the target board, but you can
6372 write into it over the network. GDB's support consists only of
6373 support for fast loading into the emulated ROM; to debug, you must use
6374 another protocol, such as standard remote protocol. The usual
6375 sequence is something like
6377 target nrom <netrom-hostname>
6379 target remote <netrom-hostname>:1235
6383 GDB now includes support for the Apple Macintosh, as a host only. It
6384 may be run as either an MPW tool or as a standalone application, and
6385 it can debug through the serial port. All the usual GDB commands are
6386 available, but to the target command, you must supply "serial" as the
6387 device type instead of "/dev/ttyXX". See mpw-README in the main
6388 directory for more information on how to build. The MPW configuration
6389 scripts */mpw-config.in support only a few targets, and only the
6390 mips-idt-ecoff target has been tested.
6394 GDB configuration now uses autoconf. This is not user-visible,
6395 but does simplify configuration and building.
6399 GDB now supports hpux10.
6401 *** Changes in GDB-4.14:
6403 * New native configurations
6405 x86 FreeBSD i[345]86-*-freebsd
6406 x86 NetBSD i[345]86-*-netbsd
6407 NS32k NetBSD ns32k-*-netbsd
6408 Sparc NetBSD sparc-*-netbsd
6412 A29K VxWorks a29k-*-vxworks
6413 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6414 CPU32 EST-300 emulator m68*-*-est*
6415 PowerPC ELF powerpc-*-elf
6418 * Alpha OSF/1 support for procfs
6420 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6421 possible to attach to running processes. As the mounting of the /proc
6422 filesystem is optional on the Alpha, GDB automatically determines
6423 the availability of /proc during startup. This can lead to problems
6424 if /proc is unmounted after GDB has been started.
6426 * Arguments to user-defined commands
6428 User commands may accept up to 10 arguments separated by whitespace.
6429 Arguments are accessed within the user command via $arg0..$arg9. A
6432 print $arg0 + $arg1 + $arg2
6434 To execute the command use:
6437 Defines the command "adder" which prints the sum of its three arguments.
6438 Note the arguments are text substitutions, so they may reference variables,
6439 use complex expressions, or even perform inferior function calls.
6441 * New `if' and `while' commands
6443 This makes it possible to write more sophisticated user-defined
6444 commands. Both commands take a single argument, which is the
6445 expression to evaluate, and must be followed by the commands to
6446 execute, one per line, if the expression is nonzero, the list being
6447 terminated by the word `end'. The `if' command list may include an
6448 `else' word, which causes the following commands to be executed only
6449 if the expression is zero.
6451 * Fortran source language mode
6453 GDB now includes partial support for Fortran 77. It will recognize
6454 Fortran programs and can evaluate a subset of Fortran expressions, but
6455 variables and functions may not be handled correctly. GDB will work
6456 with G77, but does not yet know much about symbols emitted by other
6459 * Better HPUX support
6461 Most debugging facilities now work on dynamic executables for HPPAs
6462 running hpux9 or later. You can attach to running dynamically linked
6463 processes, but by default the dynamic libraries will be read-only, so
6464 for instance you won't be able to put breakpoints in them. To change
6465 that behavior do the following before running the program:
6471 This will cause the libraries to be mapped private and read-write.
6472 To revert to the normal behavior, do this:
6478 You cannot set breakpoints or examine data in the library until after
6479 the library is loaded if the function/data symbols do not have
6482 GDB can now also read debug symbols produced by the HP C compiler on
6483 HPPAs (sorry, no C++, Fortran or 68k support).
6485 * Target byte order now dynamically selectable
6487 You can choose which byte order to use with a target system, via the
6488 commands "set endian big" and "set endian little", and you can see the
6489 current setting by using "show endian". You can also give the command
6490 "set endian auto", in which case GDB will use the byte order
6491 associated with the executable. Currently, only embedded MIPS
6492 configurations support dynamic selection of target byte order.
6494 * New DOS host serial code
6496 This version uses DPMI interrupts to handle buffered I/O, so you
6497 no longer need to run asynctsr when debugging boards connected to
6500 *** Changes in GDB-4.13:
6502 * New "complete" command
6504 This lists all the possible completions for the rest of the line, if it
6505 were to be given as a command itself. This is intended for use by emacs.
6507 * Trailing space optional in prompt
6509 "set prompt" no longer adds a space for you after the prompt you set. This
6510 allows you to set a prompt which ends in a space or one that does not.
6512 * Breakpoint hit counts
6514 "info break" now displays a count of the number of times the breakpoint
6515 has been hit. This is especially useful in conjunction with "ignore"; you
6516 can ignore a large number of breakpoint hits, look at the breakpoint info
6517 to see how many times the breakpoint was hit, then run again, ignoring one
6518 less than that number, and this will get you quickly to the last hit of
6521 * Ability to stop printing at NULL character
6523 "set print null-stop" will cause GDB to stop printing the characters of
6524 an array when the first NULL is encountered. This is useful when large
6525 arrays actually contain only short strings.
6527 * Shared library breakpoints
6529 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6530 breakpoints in shared libraries before the executable is run.
6532 * Hardware watchpoints
6534 There is a new hardware breakpoint for the watch command for sparclite
6535 targets. See gdb/sparclite/hw_breakpoint.note.
6537 Hardware watchpoints are also now supported under GNU/Linux.
6541 Annotations have been added. These are for use with graphical interfaces,
6542 and are still experimental. Currently only gdba.el uses these.
6544 * Improved Irix 5 support
6546 GDB now works properly with Irix 5.2.
6548 * Improved HPPA support
6550 GDB now works properly with the latest GCC and GAS.
6552 * New native configurations
6554 Sequent PTX4 i[34]86-sequent-ptx4
6555 HPPA running OSF/1 hppa*-*-osf*
6556 Atari TT running SVR4 m68*-*-sysv4*
6557 RS/6000 LynxOS rs6000-*-lynxos*
6561 OS/9000 i[34]86-*-os9k
6562 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6565 * Hitachi SH7000 and E7000-PC ICE support
6567 There is now support for communicating with the Hitachi E7000-PC ICE.
6568 This is available automatically when GDB is configured for the SH.
6572 As usual, a variety of small fixes and improvements, both generic
6573 and configuration-specific. See the ChangeLog for more detail.
6575 *** Changes in GDB-4.12:
6577 * Irix 5 is now supported
6581 GDB-4.12 on the HPPA has a number of changes which make it unable
6582 to debug the output from the currently released versions of GCC and
6583 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6584 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6585 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6588 *** Changes in GDB-4.11:
6590 * User visible changes:
6594 The "set remotedebug" option is now consistent between the mips remote
6595 target, remote targets using the gdb-specific protocol, UDI (AMD's
6596 debug protocol for the 29k) and the 88k bug monitor. It is now an
6597 integer specifying a debug level (normally 0 or 1, but 2 means more
6598 debugging info for the mips target).
6600 * DEC Alpha native support
6602 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6603 debug info, but GDB works fairly well with the DEC compiler and should
6604 work with a future GCC release. See the README file for a few
6605 Alpha-specific notes.
6607 * Preliminary thread implementation
6609 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6611 * LynxOS native and target support for 386
6613 This release has been hosted on LynxOS 2.2, and also can be configured
6614 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6617 * Improvements in C++ mangling/demangling.
6619 This release has much better g++ debugging, specifically in name
6620 mangling/demangling, virtual function calls, print virtual table,
6621 call methods, ...etc.
6623 *** Changes in GDB-4.10:
6625 * User visible changes:
6627 Remote debugging using the GDB-specific (`target remote') protocol now
6628 supports the `load' command. This is only useful if you have some
6629 other way of getting the stub to the target system, and you can put it
6630 somewhere in memory where it won't get clobbered by the download.
6632 Filename completion now works.
6634 When run under emacs mode, the "info line" command now causes the
6635 arrow to point to the line specified. Also, "info line" prints
6636 addresses in symbolic form (as well as hex).
6638 All vxworks based targets now support a user settable option, called
6639 vxworks-timeout. This option represents the number of seconds gdb
6640 should wait for responses to rpc's. You might want to use this if
6641 your vxworks target is, perhaps, a slow software simulator or happens
6642 to be on the far side of a thin network line.
6646 This release contains support for using a DEC alpha as a GDB host for
6647 cross debugging. Native alpha debugging is not supported yet.
6650 *** Changes in GDB-4.9:
6654 This is the first GDB release which is accompanied by a matching testsuite.
6655 The testsuite requires installation of dejagnu, which should be available
6656 via ftp from most sites that carry GNU software.
6660 'Cfront' style demangling has had its name changed to 'ARM' style, to
6661 emphasize that it was written from the specifications in the C++ Annotated
6662 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6663 disclaimers, it still generated too much confusion with users attempting to
6664 use gdb with AT&T cfront.
6668 GDB now uses a standard remote interface to a simulator library.
6669 So far, the library contains simulators for the Zilog Z8001/2, the
6670 Hitachi H8/300, H8/500 and Super-H.
6672 * New targets supported
6674 H8/300 simulator h8300-hitachi-hms or h8300hms
6675 H8/500 simulator h8500-hitachi-hms or h8500hms
6676 SH simulator sh-hitachi-hms or sh
6677 Z8000 simulator z8k-zilog-none or z8ksim
6678 IDT MIPS board over serial line mips-idt-ecoff
6680 Cross-debugging to GO32 targets is supported. It requires a custom
6681 version of the i386-stub.c module which is integrated with the
6682 GO32 memory extender.
6684 * New remote protocols
6686 MIPS remote debugging protocol.
6688 * New source languages supported
6690 This version includes preliminary support for Chill, a Pascal like language
6691 used by telecommunications companies. Chill support is also being integrated
6692 into the GNU compiler, but we don't know when it will be publically available.
6695 *** Changes in GDB-4.8:
6697 * HP Precision Architecture supported
6699 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6700 version of this support was available as a set of patches from the
6701 University of Utah. GDB does not support debugging of programs
6702 compiled with the HP compiler, because HP will not document their file
6703 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6704 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6706 Many problems in the preliminary version have been fixed.
6708 * Faster and better demangling
6710 We have improved template demangling and fixed numerous bugs in the GNU style
6711 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6712 character types (wchar_t) are now supported. Demangling of each symbol is now
6713 only done once, and is cached when the symbol table for a file is read in.
6714 This results in a small increase in memory usage for C programs, a moderate
6715 increase in memory usage for C++ programs, and a fantastic speedup in
6718 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6719 from the specifications in the Annotated Reference Manual, which AT&T's
6720 compiler does not actually implement.
6722 * G++ multiple inheritance compiler problem
6724 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6725 inheritance lattices was reworked to properly discover ambiguities. We
6726 recently found an example which causes this new algorithm to fail in a
6727 very subtle way, producing bad debug information for those classes.
6728 The file 'gcc.patch' (in this directory) can be applied to gcc to
6729 circumvent the problem. A future GCC release will contain a complete
6732 The previous G++ debug info problem (mentioned below for the gdb-4.7
6733 release) is fixed in gcc version 2.3.2.
6735 * Improved configure script
6737 The `configure' script will now attempt to guess your system type if
6738 you don't supply a host system type. The old scheme of supplying a
6739 host system triplet is preferable over using this. All the magic is
6740 done in the new `config.guess' script. Examine it for details.
6742 We have also brought our configure script much more in line with the FSF's
6743 version. It now supports the --with-xxx options. In particular,
6744 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6745 The resulting GDB will not be able to read arbitrary object file formats --
6746 only the format ``expected'' to be used on the configured target system.
6747 We hope to make this the default in a future release.
6749 * Documentation improvements
6751 There's new internal documentation on how to modify GDB, and how to
6752 produce clean changes to the code. We implore people to read it
6753 before submitting changes.
6755 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6756 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6757 `info' files are also provided. To build `info' files from scratch,
6758 you will need the latest `makeinfo' release, which will be available in
6759 a future texinfo-X.Y release.
6761 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6762 We're not sure exactly which versions have this problem, but it has
6763 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6764 or better. If that isn't possible, there is a patch in
6765 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6766 around this problem.
6770 GDB now supports array constants that can be used in expressions typed in by
6771 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6772 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6775 The new directory `gdb/sparclite' contains a program that demonstrates
6776 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6778 * New native hosts supported
6780 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6781 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6783 * New targets supported
6785 AMD 29k family via UDI a29k-amd-udi or udi29k
6787 * New file formats supported
6789 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6790 HPUX core files, and SCO 3.2v2 core files.
6794 Attaching to processes now works again; thanks for the many bug reports.
6796 We have also stomped on a bunch of core dumps caused by
6797 printf_filtered("%s") problems.
6799 We eliminated a copyright problem on the rpc and ptrace header files
6800 for VxWorks, which was discovered at the last minute during the 4.7
6801 release. You should now be able to build a VxWorks GDB.
6803 You can now interrupt gdb while an attached process is running. This
6804 will cause the attached process to stop, and give control back to GDB.
6806 We fixed problems caused by using too many file descriptors
6807 for reading symbols from object files and libraries. This was
6808 especially a problem for programs that used many (~100) shared
6811 The `step' command now only enters a subroutine if there is line number
6812 information for the subroutine. Otherwise it acts like the `next'
6813 command. Previously, `step' would enter subroutines if there was
6814 any debugging information about the routine. This avoids problems
6815 when using `cc -g1' on MIPS machines.
6817 * Internal improvements
6819 GDB's internal interfaces have been improved to make it easier to support
6820 debugging of multiple languages in the future.
6822 GDB now uses a common structure for symbol information internally.
6823 Minimal symbols (derived from linkage symbols in object files), partial
6824 symbols (from a quick scan of debug information), and full symbols
6825 contain a common subset of information, making it easier to write
6826 shared code that handles any of them.
6828 * New command line options
6830 We now accept --silent as an alias for --quiet.
6834 The memory-mapped-malloc library is now licensed under the GNU Library
6835 General Public License.
6837 *** Changes in GDB-4.7:
6839 * Host/native/target split
6841 GDB has had some major internal surgery to untangle the support for
6842 hosts and remote targets. Now, when you configure GDB for a remote
6843 target, it will no longer load in all of the support for debugging
6844 local programs on the host. When fully completed and tested, this will
6845 ensure that arbitrary host/target combinations are possible.
6847 The primary conceptual shift is to separate the non-portable code in
6848 GDB into three categories. Host specific code is required any time GDB
6849 is compiled on that host, regardless of the target. Target specific
6850 code relates to the peculiarities of the target, but can be compiled on
6851 any host. Native specific code is everything else: it can only be
6852 built when the host and target are the same system. Child process
6853 handling and core file support are two common `native' examples.
6855 GDB's use of /proc for controlling Unix child processes is now cleaner.
6856 It has been split out into a single module under the `target_ops' vector,
6857 plus two native-dependent functions for each system that uses /proc.
6859 * New hosts supported
6861 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6862 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6863 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6865 * New targets supported
6867 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6868 68030 and CPU32 m68030-*-*, m68332-*-*
6870 * New native hosts supported
6872 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6873 (386bsd is not well tested yet)
6874 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6876 * New file formats supported
6878 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6879 supports reading of `a.out.adobe' object files, which are an a.out
6880 format extended with minimal information about multiple sections.
6884 `show copying' is the same as the old `info copying'.
6885 `show warranty' is the same as `info warrantee'.
6886 These were renamed for consistency. The old commands continue to work.
6888 `info handle' is a new alias for `info signals'.
6890 You can now define pre-command hooks, which attach arbitrary command
6891 scripts to any command. The commands in the hook will be executed
6892 prior to the user's command. You can also create a hook which will be
6893 executed whenever the program stops. See gdb.texinfo.
6897 We now deal with Cfront style name mangling, and can even extract type
6898 info from mangled symbols. GDB can automatically figure out which
6899 symbol mangling style your C++ compiler uses.
6901 Calling of methods and virtual functions has been improved as well.
6905 The crash that occured when debugging Sun Ansi-C compiled binaries is
6906 fixed. This was due to mishandling of the extra N_SO stabs output
6909 We also finally got Ultrix 4.2 running in house, and fixed core file
6910 support, with help from a dozen people on the net.
6912 John M. Farrell discovered that the reason that single-stepping was so
6913 slow on all of the Mips based platforms (primarily SGI and DEC) was
6914 that we were trying to demangle and lookup a symbol used for internal
6915 purposes on every instruction that was being stepped through. Changing
6916 the name of that symbol so that it couldn't be mistaken for a C++
6917 mangled symbol sped things up a great deal.
6919 Rich Pixley sped up symbol lookups in general by getting much smarter
6920 about when C++ symbol mangling is necessary. This should make symbol
6921 completion (TAB on the command line) much faster. It's not as fast as
6922 we'd like, but it's significantly faster than gdb-4.6.
6926 A new user controllable variable 'call_scratch_address' can
6927 specify the location of a scratch area to be used when GDB
6928 calls a function in the target. This is necessary because the
6929 usual method of putting the scratch area on the stack does not work
6930 in systems that have separate instruction and data spaces.
6932 We integrated changes to support the 29k UDI (Universal Debugger
6933 Interface), but discovered at the last minute that we didn't have all
6934 of the appropriate copyright paperwork. We are working with AMD to
6935 resolve this, and hope to have it available soon.
6939 We have sped up the remote serial line protocol, especially for targets
6940 with lots of registers. It now supports a new `expedited status' ('T')
6941 message which can be used in place of the existing 'S' status message.
6942 This allows the remote stub to send only the registers that GDB
6943 needs to make a quick decision about single-stepping or conditional
6944 breakpoints, eliminating the need to fetch the entire register set for
6945 each instruction being stepped through.
6947 The GDB remote serial protocol now implements a write-through cache for
6948 registers, only re-reading the registers if the target has run.
6950 There is also a new remote serial stub for SPARC processors. You can
6951 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6952 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6953 processor with a serial port.
6957 Configure.in files have become much easier to read and modify. A new
6958 `table driven' format makes it more obvious what configurations are
6959 supported, and what files each one uses.
6963 There is a new opcodes library which will eventually contain all of the
6964 disassembly routines and opcode tables. At present, it only contains
6965 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6966 disassembler (binutils/objdump) to share these routines.
6968 The libiberty library is now copylefted under the GNU Library General
6969 Public License. This allows more liberal use, and was done so libg++
6970 can use it. This makes no difference to GDB, since the Library License
6971 grants all the rights from the General Public License.
6975 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6976 reference to the stabs symbol info used by the debugger. It is (as far
6977 as we know) the only published document on this fascinating topic. We
6978 encourage you to read it, compare it to the stabs information on your
6979 system, and send improvements on the document in general (to
6980 bug-gdb@prep.ai.mit.edu).
6982 And, of course, many bugs have been fixed.
6985 *** Changes in GDB-4.6:
6987 * Better support for C++ function names
6989 GDB now accepts as input the "demangled form" of C++ overloaded function
6990 names and member function names, and can do command completion on such names
6991 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6992 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6993 Make use of command completion, it is your friend.
6995 GDB also now accepts a variety of C++ mangled symbol formats. They are
6996 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6997 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6998 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6999 for the list of formats.
7001 * G++ symbol mangling problem
7003 Recent versions of gcc have a bug in how they emit debugging information for
7004 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7005 directory) can be applied to gcc to fix the problem. Alternatively, if you
7006 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7007 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7008 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7011 * New 'maintenance' command
7013 All of the commands related to hacking GDB internals have been moved out of
7014 the main command set, and now live behind the 'maintenance' command. This
7015 can also be abbreviated as 'mt'. The following changes were made:
7017 dump-me -> maintenance dump-me
7018 info all-breakpoints -> maintenance info breakpoints
7019 printmsyms -> maintenance print msyms
7020 printobjfiles -> maintenance print objfiles
7021 printpsyms -> maintenance print psymbols
7022 printsyms -> maintenance print symbols
7024 The following commands are new:
7026 maintenance demangle Call internal GDB demangler routine to
7027 demangle a C++ link name and prints the result.
7028 maintenance print type Print a type chain for a given symbol
7030 * Change to .gdbinit file processing
7032 We now read the $HOME/.gdbinit file before processing the argv arguments
7033 (e.g. reading symbol files or core files). This allows global parameters to
7034 be set, which will apply during the symbol reading. The ./.gdbinit is still
7035 read after argv processing.
7037 * New hosts supported
7039 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7041 GNU/Linux support i386-unknown-linux or linux
7043 We are also including code to support the HP/PA running BSD and HPUX. This
7044 is almost guaranteed not to work, as we didn't have time to test or build it
7045 for this release. We are including it so that the more adventurous (or
7046 masochistic) of you can play with it. We also had major problems with the
7047 fact that the compiler that we got from HP doesn't support the -g option.
7050 * New targets supported
7052 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7054 * More smarts about finding #include files
7056 GDB now remembers the compilation directory for all include files, and for
7057 all files from which C is generated (like yacc and lex sources). This
7058 greatly improves GDB's ability to find yacc/lex sources, and include files,
7059 especially if you are debugging your program from a directory different from
7060 the one that contains your sources.
7062 We also fixed a bug which caused difficulty with listing and setting
7063 breakpoints in include files which contain C code. (In the past, you had to
7064 try twice in order to list an include file that you hadn't looked at before.)
7066 * Interesting infernals change
7068 GDB now deals with arbitrary numbers of sections, where the symbols for each
7069 section must be relocated relative to that section's landing place in the
7070 target's address space. This work was needed to support ELF with embedded
7071 stabs used by Solaris-2.0.
7073 * Bug fixes (of course!)
7075 There have been loads of fixes for the following things:
7076 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7077 i960, stabs, DOS(GO32), procfs, etc...
7079 See the ChangeLog for details.
7081 *** Changes in GDB-4.5:
7083 * New machines supported (host and target)
7085 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7087 SGI Irix-4.x mips-sgi-irix4 or iris4
7089 * New malloc package
7091 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7092 Mmalloc is capable of handling mutiple heaps of memory. It is also
7093 capable of saving a heap to a file, and then mapping it back in later.
7094 This can be used to greatly speedup the startup of GDB by using a
7095 pre-parsed symbol table which lives in a mmalloc managed heap. For
7096 more details, please read mmalloc/mmalloc.texi.
7100 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7101 'help info proc' for details.
7103 * MIPS ecoff symbol table format
7105 The code that reads MIPS symbol table format is now supported on all hosts.
7106 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7109 * File name changes for MS-DOS
7111 Many files in the config directories have been renamed to make it easier to
7112 support GDB on MS-DOSe systems (which have very restrictive file name
7113 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7114 environment) is close to working but has some remaining problems. Note
7115 that debugging of DOS programs is not supported, due to limitations
7116 in the ``operating system'', but it can be used to host cross-debugging.
7118 * Cross byte order fixes
7120 Many fixes have been made to support cross debugging of Sparc and MIPS
7121 targets from hosts whose byte order differs.
7123 * New -mapped and -readnow options
7125 If memory-mapped files are available on your system through the 'mmap'
7126 system call, you can use the -mapped option on the `file' or
7127 `symbol-file' commands to cause GDB to write the symbols from your
7128 program into a reusable file. If the program you are debugging is
7129 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7130 Future GDB debugging sessions will notice the presence of this file,
7131 and will quickly map in symbol information from it, rather than reading
7132 the symbol table from the executable program. Using the '-mapped'
7133 option in a GDB `file' or `symbol-file' command has the same effect as
7134 starting GDB with the '-mapped' command-line option.
7136 You can cause GDB to read the entire symbol table immediately by using
7137 the '-readnow' option with any of the commands that load symbol table
7138 information (or on the GDB command line). This makes the command
7139 slower, but makes future operations faster.
7141 The -mapped and -readnow options are typically combined in order to
7142 build a `fred.syms' file that contains complete symbol information.
7143 A simple GDB invocation to do nothing but build a `.syms' file for future
7146 gdb -batch -nx -mapped -readnow programname
7148 The `.syms' file is specific to the host machine on which GDB is run.
7149 It holds an exact image of GDB's internal symbol table. It cannot be
7150 shared across multiple host platforms.
7152 * longjmp() handling
7154 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7155 siglongjmp() without losing control. This feature has not yet been ported to
7156 all systems. It currently works on many 386 platforms, all MIPS-based
7157 platforms (SGI, DECstation, etc), and Sun3/4.
7161 Preliminary work has been put in to support the new Solaris OS from Sun. At
7162 this time, it can control and debug processes, but it is not capable of
7167 As always, many many bug fixes. The major areas were with g++, and mipsread.
7168 People using the MIPS-based platforms should experience fewer mysterious
7169 crashes and trashed symbol tables.
7171 *** Changes in GDB-4.4:
7173 * New machines supported (host and target)
7175 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7177 BSD Reno on Vax vax-dec-bsd
7178 Ultrix on Vax vax-dec-ultrix
7180 * New machines supported (target)
7182 AMD 29000 embedded, using EBMON a29k-none-none
7186 GDB continues to improve its handling of C++. `References' work better.
7187 The demangler has also been improved, and now deals with symbols mangled as
7188 per the Annotated C++ Reference Guide.
7190 GDB also now handles `stabs' symbol information embedded in MIPS
7191 `ecoff' symbol tables. Since the ecoff format was not easily
7192 extensible to handle new languages such as C++, this appeared to be a
7193 good way to put C++ debugging info into MIPS binaries. This option
7194 will be supported in the GNU C compiler, version 2, when it is
7197 * New features for SVR4
7199 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7200 shared libraries. Debugging dynamically linked programs should present
7201 only minor differences from debugging statically linked programs.
7203 The `info proc' command will print out information about any process
7204 on an SVR4 system (including the one you are debugging). At the moment,
7205 it prints the address mappings of the process.
7207 If you bring up GDB on another SVR4 system, please send mail to
7208 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7210 * Better dynamic linking support in SunOS
7212 Reading symbols from shared libraries which contain debugging symbols
7213 now works properly. However, there remain issues such as automatic
7214 skipping of `transfer vector' code during function calls, which
7215 make it harder to debug code in a shared library, than to debug the
7216 same code linked statically.
7220 GDB is now using the latest `getopt' routines from the FSF. This
7221 version accepts the -- prefix for options with long names. GDB will
7222 continue to accept the old forms (-option and +option) as well.
7223 Various single letter abbreviations for options have been explicity
7224 added to the option table so that they won't get overshadowed in the
7225 future by other options that begin with the same letter.
7229 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7230 Many assorted bugs have been handled. Many more remain to be handled.
7231 See the various ChangeLog files (primarily in gdb and bfd) for details.
7234 *** Changes in GDB-4.3:
7236 * New machines supported (host and target)
7238 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7239 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7240 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7242 * Almost SCO Unix support
7244 We had hoped to support:
7245 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7246 (except for core file support), but we discovered very late in the release
7247 that it has problems with process groups that render gdb unusable. Sorry
7248 about that. I encourage people to fix it and post the fixes.
7250 * Preliminary ELF and DWARF support
7252 GDB can read ELF object files on System V Release 4, and can handle
7253 debugging records for C, in DWARF format, in ELF files. This support
7254 is preliminary. If you bring up GDB on another SVR4 system, please
7255 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7260 GDB now uses the latest `readline' library. One user-visible change
7261 is that two tabs will list possible command completions, which previously
7262 required typing M-? (meta-question mark, or ESC ?).
7266 The `stepi' bug that many of you noticed has been squashed.
7267 Many bugs in C++ have been handled. Many more remain to be handled.
7268 See the various ChangeLog files (primarily in gdb and bfd) for details.
7270 * State of the MIPS world (in case you wondered):
7272 GDB can understand the symbol tables emitted by the compilers
7273 supplied by most vendors of MIPS-based machines, including DEC. These
7274 symbol tables are in a format that essentially nobody else uses.
7276 Some versions of gcc come with an assembler post-processor called
7277 mips-tfile. This program is required if you want to do source-level
7278 debugging of gcc-compiled programs. I believe FSF does not ship
7279 mips-tfile with gcc version 1, but it will eventually come with gcc
7282 Debugging of g++ output remains a problem. g++ version 1.xx does not
7283 really support it at all. (If you're lucky, you should be able to get
7284 line numbers and stack traces to work, but no parameters or local
7285 variables.) With some work it should be possible to improve the
7288 When gcc version 2 is released, you will have somewhat better luck.
7289 However, even then you will get confusing results for inheritance and
7292 We will eventually provide full debugging of g++ output on
7293 DECstations. This will probably involve some kind of stabs-in-ecoff
7294 encapulation, but the details have not been worked out yet.
7297 *** Changes in GDB-4.2:
7299 * Improved configuration
7301 Only one copy of `configure' exists now, and it is not self-modifying.
7302 Porting BFD is simpler.
7306 The `step' and `next' commands now only stop at the first instruction
7307 of a source line. This prevents the multiple stops that used to occur
7308 in switch statements, for-loops, etc. `Step' continues to stop if a
7309 function that has debugging information is called within the line.
7313 Lots of small bugs fixed. More remain.
7315 * New host supported (not target)
7317 Intel 386 PC clone running Mach i386-none-mach
7320 *** Changes in GDB-4.1:
7322 * Multiple source language support
7324 GDB now has internal scaffolding to handle several source languages.
7325 It determines the type of each source file from its filename extension,
7326 and will switch expression parsing and number formatting to match the
7327 language of the function in the currently selected stack frame.
7328 You can also specifically set the language to be used, with
7329 `set language c' or `set language modula-2'.
7333 GDB now has preliminary support for the GNU Modula-2 compiler,
7334 currently under development at the State University of New York at
7335 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7336 continue through the fall of 1991 and into 1992.
7338 Other Modula-2 compilers are currently not supported, and attempting to
7339 debug programs compiled with them will likely result in an error as the
7340 symbol table is read. Feel free to work on it, though!
7342 There are hooks in GDB for strict type checking and range checking,
7343 in the `Modula-2 philosophy', but they do not currently work.
7347 GDB can now write to executable and core files (e.g. patch
7348 a variable's value). You must turn this switch on, specify
7349 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7350 by assigning a new value to a variable. Modifications take
7353 * Automatic SunOS shared library reading
7355 When you run your program, GDB automatically determines where its
7356 shared libraries (if any) have been loaded, and reads their symbols.
7357 The `share' command is no longer needed. This also works when
7358 examining core files.
7362 You can specify the number of lines that the `list' command shows.
7365 * New machines supported (host and target)
7367 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7368 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7369 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7371 * New hosts supported (not targets)
7373 IBM RT/PC: romp-ibm-aix or rtpc
7375 * New targets supported (not hosts)
7377 AMD 29000 embedded with COFF a29k-none-coff
7378 AMD 29000 embedded with a.out a29k-none-aout
7379 Ultracomputer remote kernel debug a29k-nyu-kern
7381 * New remote interfaces
7387 *** Changes in GDB-4.0:
7391 Wide output is wrapped at good places to make the output more readable.
7393 Gdb now supports cross-debugging from a host machine of one type to a
7394 target machine of another type. Communication with the target system
7395 is over serial lines. The ``target'' command handles connecting to the
7396 remote system; the ``load'' command will download a program into the
7397 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7398 also supports debugging of realtime processes running under VxWorks,
7399 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7400 stub on the target system.
7402 New CPUs supported include the AMD 29000 and Intel 960.
7404 GDB now reads object files and symbol tables via a ``binary file''
7405 library, which allows a single copy of GDB to debug programs of multiple
7406 object file types such as a.out and coff.
7408 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7409 refcard.dvi and refcard.ps are available to format it).
7412 * Control-Variable user interface simplified
7414 All variables that control the operation of the debugger can be set
7415 by the ``set'' command, and displayed by the ``show'' command.
7417 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7418 ``Show prompt'' produces the response:
7419 Gdb's prompt is new-gdb=>.
7421 What follows are the NEW set commands. The command ``help set'' will
7422 print a complete list of old and new set commands. ``help set FOO''
7423 will give a longer description of the variable FOO. ``show'' will show
7424 all of the variable descriptions and their current settings.
7426 confirm on/off: Enables warning questions for operations that are
7427 hard to recover from, e.g. rerunning the program while
7428 it is already running. Default is ON.
7430 editing on/off: Enables EMACS style command line editing
7431 of input. Previous lines can be recalled with
7432 control-P, the current line can be edited with control-B,
7433 you can search for commands with control-R, etc.
7436 history filename NAME: NAME is where the gdb command history
7437 will be stored. The default is .gdb_history,
7438 or the value of the environment variable
7441 history size N: The size, in commands, of the command history. The
7442 default is 256, or the value of the environment variable
7445 history save on/off: If this value is set to ON, the history file will
7446 be saved after exiting gdb. If set to OFF, the
7447 file will not be saved. The default is OFF.
7449 history expansion on/off: If this value is set to ON, then csh-like
7450 history expansion will be performed on
7451 command line input. The default is OFF.
7453 radix N: Sets the default radix for input and output. It can be set
7454 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7455 in the current radix, so "set radix 10" is always a no-op.
7457 height N: This integer value is the number of lines on a page. Default
7458 is 24, the current `stty rows'' setting, or the ``li#''
7459 setting from the termcap entry matching the environment
7462 width N: This integer value is the number of characters on a line.
7463 Default is 80, the current `stty cols'' setting, or the ``co#''
7464 setting from the termcap entry matching the environment
7467 Note: ``set screensize'' is obsolete. Use ``set height'' and
7468 ``set width'' instead.
7470 print address on/off: Print memory addresses in various command displays,
7471 such as stack traces and structure values. Gdb looks
7472 more ``symbolic'' if you turn this off; it looks more
7473 ``machine level'' with it on. Default is ON.
7475 print array on/off: Prettyprint arrays. New convenient format! Default
7478 print demangle on/off: Print C++ symbols in "source" form if on,
7481 print asm-demangle on/off: Same, for assembler level printouts
7484 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7487 * Support for Epoch Environment.
7489 The epoch environment is a version of Emacs v18 with windowing. One
7490 new command, ``inspect'', is identical to ``print'', except that if you
7491 are running in the epoch environment, the value is printed in its own
7495 * Support for Shared Libraries
7497 GDB can now debug programs and core files that use SunOS shared libraries.
7498 Symbols from a shared library cannot be referenced
7499 before the shared library has been linked with the program (this
7500 happens after you type ``run'' and before the function main() is entered).
7501 At any time after this linking (including when examining core files
7502 from dynamically linked programs), gdb reads the symbols from each
7503 shared library when you type the ``sharedlibrary'' command.
7504 It can be abbreviated ``share''.
7506 sharedlibrary REGEXP: Load shared object library symbols for files
7507 matching a unix regular expression. No argument
7508 indicates to load symbols for all shared libraries.
7510 info sharedlibrary: Status of loaded shared libraries.
7515 A watchpoint stops execution of a program whenever the value of an
7516 expression changes. Checking for this slows down execution
7517 tremendously whenever you are in the scope of the expression, but is
7518 quite useful for catching tough ``bit-spreader'' or pointer misuse
7519 problems. Some machines such as the 386 have hardware for doing this
7520 more quickly, and future versions of gdb will use this hardware.
7522 watch EXP: Set a watchpoint (breakpoint) for an expression.
7524 info watchpoints: Information about your watchpoints.
7526 delete N: Deletes watchpoint number N (same as breakpoints).
7527 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7528 enable N: Re-enables watchpoint number N (same as breakpoints).
7531 * C++ multiple inheritance
7533 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7536 * C++ exception handling
7538 Gdb now supports limited C++ exception handling. Besides the existing
7539 ability to breakpoint on an exception handler, gdb can breakpoint on
7540 the raising of an exception (before the stack is peeled back to the
7543 catch FOO: If there is a FOO exception handler in the dynamic scope,
7544 set a breakpoint to catch exceptions which may be raised there.
7545 Multiple exceptions (``catch foo bar baz'') may be caught.
7547 info catch: Lists all exceptions which may be caught in the
7548 current stack frame.
7551 * Minor command changes
7553 The command ``call func (arg, arg, ...)'' now acts like the print
7554 command, except it does not print or save a value if the function's result
7555 is void. This is similar to dbx usage.
7557 The ``up'' and ``down'' commands now always print the frame they end up
7558 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7559 frames without printing.
7561 * New directory command
7563 'dir' now adds directories to the FRONT of the source search path.
7564 The path starts off empty. Source files that contain debug information
7565 about the directory in which they were compiled can be found even
7566 with an empty path; Sun CC and GCC include this information. If GDB can't
7567 find your source file in the current directory, type "dir .".
7569 * Configuring GDB for compilation
7571 For normal use, type ``./configure host''. See README or gdb.texinfo
7574 GDB now handles cross debugging. If you are remotely debugging between
7575 two different machines, type ``./configure host -target=targ''.
7576 Host is the machine where GDB will run; targ is the machine
7577 where the program that you are debugging will run.