1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.3
6 * 'thread-exited' event is now available in the annotations interface.
8 * New built-in convenience variables $_gdb_major and $_gdb_minor
9 provide the GDB version. They are handy for conditionally using
10 features available only in or since specific GDB versions, in
11 scripts that should work error-free with many different versions,
12 such as in system-wide init files.
14 * GDB now supports Thread Local Storage (TLS) variables on several
15 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
16 architectures require kernel changes. TLS is not yet supported for
17 amd64 and i386 process core dumps.
19 * Support for Pointer Authentication on AArch64 Linux.
21 * Two new convenience functions $_cimag and $_creal that extract the
22 imaginary and real parts respectively from complex numbers.
24 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
25 provide the exitcode or exit status of the shell commands launched by
26 GDB commands such as "shell", "pipe" and "make".
30 ** The gdb.Value type has a new method 'format_string' which returns a
31 string representing the value. The formatting is controlled by the
32 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
33 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
34 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
36 ** gdb.Type has a new property 'objfile' which returns the objfile the
39 ** The frame information printed by the python frame filtering code
40 is now consistent with what the 'backtrace' command prints when
41 there are no filters, or when the 'backtrace' '-no-filters' option
44 ** The new function gdb.lookup_static_symbol can be used to look up
45 symbols with static linkage.
47 ** gdb.Objfile has new methods 'lookup_global_symbol' and
48 'lookup_static_symbol' to lookup a symbol from this objfile only.
52 | [COMMAND] | SHELL_COMMAND
53 | -d DELIM COMMAND DELIM SHELL_COMMAND
54 pipe [COMMAND] | SHELL_COMMAND
55 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
56 Executes COMMAND and sends its output to SHELL_COMMAND.
57 With no COMMAND, repeat the last executed command
58 and send its output to SHELL_COMMAND.
60 with SETTING [VALUE] [-- COMMAND]
61 w SETTING [VALUE] [-- COMMAND]
62 Temporarily set SETTING, run COMMAND, and restore SETTING.
63 Usage: with SETTING -- COMMAND
64 With no COMMAND, repeats the last executed command.
65 SETTING is any GDB setting you can change with the "set"
66 subcommands. For example, 'with language c -- print someobj'
67 temporarily switches to the C language in order to print someobj.
68 Settings can be combined: 'w lang c -- w print elements unlimited --
69 usercmd' switches to the C language and runs usercmd with no limit
70 of array elements to print.
72 maint with SETTING [VALUE] [-- COMMAND]
73 Like "with", but works with "maintenance set" settings.
75 set may-call-functions [on|off]
76 show may-call-functions
77 This controls whether GDB will attempt to call functions in
78 the program, such as with expressions in the print command. It
79 defaults to on. Calling functions in the program being debugged
80 can have undesired side effects. It is now possible to forbid
81 such function calls. If function calls are forbidden, GDB will throw
82 an error when a command (such as print expression) calls a function
85 set print finish [on|off]
87 This controls whether the `finish' command will display the value
88 that is returned by the current function. When `off', the value is
89 still entered into the value history, but it is not printed. The
94 Allows deeply nested structures to be simplified when printing by
95 replacing deeply nested parts (beyond the max-depth) with ellipses.
96 The default max-depth is 20, but this can be set to unlimited to get
97 the old behavior back.
99 set logging debugredirect [on|off]
100 By default, GDB debug output will go to both the terminal and the logfile.
101 Set if you want debug output to go only to the log file.
103 set style title foreground COLOR
104 set style title background COLOR
105 set style title intensity VALUE
106 Control the styling of titles.
108 set style highlight foreground COLOR
109 set style highlight background COLOR
110 set style highlight intensity VALUE
111 Control the styling of highlightings.
113 maint set test-settings KIND
114 maint show test-settings KIND
115 A set of commands used by the testsuite for exercising the settings
118 set print frame-info [short-location|location|location-and-address
119 |source-and-location|source-line|auto]
120 show print frame-info
121 This controls what frame information is printed by the commands printing
122 a frame. This setting will e.g. influence the behaviour of 'backtrace',
123 'frame', 'stepi'. The python frame filtering also respect this setting.
124 The 'backtrace' '-frame-info' option can override this global setting.
129 The "help" command uses the title style to enhance the
130 readibility of its output by styling the classes and
134 Similarly to "help", the "apropos" command also uses the
135 title style for the command names. "apropos" accepts now
136 a flag "-v" (verbose) to show the full documentation
137 of matching commands and to use the highlight style to mark
138 the documentation parts matching REGEXP.
142 The GDB printf and eval commands can now print C-style and Ada-style
143 string convenience variables without calling functions in the program.
144 This allows to do formatted printing of strings without having
145 a running inferior, or when debugging a core dump.
148 The "show style" and its subcommands are now styling
149 a style name in their output using its own style, to help
150 the user visualize the different styles.
152 set print frame-arguments
153 The new value 'presence' indicates to only indicate the presence of
154 arguments using ..., instead of printing argument names and values.
156 set print raw-frame-arguments
157 show print raw-frame-arguments
159 These commands replace the similarly-named "set/show print raw
160 frame-arguments" commands (now with a dash instead of a space). The
161 old commands are now deprecated and may be removed in a future
164 maint test-options require-delimiter
165 maint test-options unknown-is-error
166 maint test-options unknown-is-operand
167 maint show test-options-completion-result
168 Commands used by the testsuite to validate the command options
171 * New command options, command completion
173 GDB now has a standard infrastructure to support dash-style command
174 options ('-OPT'). One benefit is that commands that use it can
175 easily support completion of command line arguments. Try "CMD
176 -[TAB]" or "help CMD" to find options supported by a command. Over
177 time, we intend to migrate most commands to this infrastructure. A
178 number of commands got support for new command options in this
181 ** The "print" and "compile print" commands now support a number of
182 options that allow overriding relevant global print settings as
183 set by "set print" subcommands:
187 -array-indexes [on|off]
188 -elements NUMBER|unlimited
192 -repeats NUMBER|unlimited
193 -static-members [on|off]
198 Note that because the "print"/"compile print" commands accept
199 arbitrary expressions which may look like options (including
200 abbreviations), if you specify any command option, then you must
201 use a double dash ("--") to mark the end of argument processing.
203 ** The "backtrace" command now supports a number of options that
204 allow overriding relevant global print settings as set by "set
205 backtrace" and "set print" subcommands:
207 -entry-values no|only|preferred|if-needed|both|compact|default
208 -frame-arguments all|scalars|none
209 -raw-frame-arguments [on|off]
210 -frame-info auto|source-line|location|source-and-location
211 |location-and-address|short-location
215 In addition, the full/no-filters/hide qualifiers are now also
216 exposed as command options too:
222 ** The "frame apply", "tfaas" and "faas" commands similarly now
223 support the following options:
228 All options above can also be abbreviated. The argument of boolean
229 (on/off) options can be 0/1 too, and also the argument is assumed
230 "on" if omitted. This allows writing compact command invocations,
233 (gdb) p -r -p -o 0 -- *myptr
235 The above is equivalent to:
237 (gdb) print -raw -pretty -object off -- *myptr
239 ** The "info types" command now supports the '-q' flag to disable
240 printing of some header information in a similar fashion to "info
241 variables" and "info functions".
243 * Completion improvements
245 ** GDB can now complete the options of the "thread apply all" and
246 "taas" commands, and their "-ascending" option can now be
249 ** GDB can now complete the options of the "info threads", "info
250 functions", "info variables", "info locals", and "info args"
253 ** GDB can now complete the options of the "compile file" and
254 "compile code" commands. The "compile file" command now
255 completes on filenames.
257 ** GDB can now complete the backtrace command's
258 "full/no-filters/hide" qualifiers.
260 * In settings, you can now abbreviate "unlimited".
262 E.g., "set print elements u" is now equivalent to "set print
268 This lists all the possible completions for the rest of the line, if it
269 were to be given as a command itself. This is intended for use by MI
270 frontends in cases when separate CLI and MI channels cannot be used.
272 -catch-throw, -catch-rethrow, and -catch-catch
273 These can be used to catch C++ exceptions in a similar fashion to
274 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
278 The testsuite now creates the files gdb.cmd (containing the arguments
279 used to launch GDB) and gdb.in (containing all the commands sent to
280 GDB) in the output directory for each test script. Multiple invocations
281 are appended with .1, .2, .3 etc.
283 * Building GDB and GDBserver now requires GNU make >= 3.82.
285 Using another implementation of the make program or an earlier version of
286 GNU make to build GDB or GDBserver is not supported.
288 *** Changes in GDB 8.3
290 * GDB and GDBserver now support access to additional registers on
291 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
294 * GDB now has experimental support for the compilation and injection of
295 C++ source code into the inferior. This beta release does not include
296 support for several language features, such as templates, constructors,
299 This feature requires GCC 7.1 or higher built with libcp1.so
302 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
303 can be passed using the '[ADDRESS]:PORT' notation, or the regular
304 'ADDRESS:PORT' method.
306 * DWARF index cache: GDB can now automatically save indices of DWARF
307 symbols on disk to speed up further loading of the same binaries.
309 * Ada task switching is now supported on aarch64-elf targets when
310 debugging a program using the Ravenscar Profile. For more information,
311 see the "Tasking Support when using the Ravenscar Profile" section
312 in the GDB user manual.
314 * GDB in batch mode now exits with status 1 if the last command to be
317 * The RISC-V target now supports target descriptions.
319 * System call catchpoints now support system call aliases on FreeBSD.
320 When the ABI of a system call changes in FreeBSD, this is
321 implemented by leaving a compatibility system call using the old ABI
322 at the existing number and allocating a new system call number for
323 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
324 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
325 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
326 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
327 so that a system call catchpoint for the 'kevent' system call will
328 catch invocations of both the 'kevent' and 'freebsd11_kevent'
329 binaries. This ensures that 'kevent' system calls are caught for
330 binaries using either the old or new ABIs.
332 * Terminal styling is now available for the CLI and the TUI. GNU
333 Source Highlight can additionally be used to provide styling of
334 source code snippets. See the "set style" commands, below, for more
337 * Removed support for old demangling styles arm, edg, gnu, hp and
342 set debug compile-cplus-types
343 show debug compile-cplus-types
344 Control the display of debug output about type conversion in the
345 C++ compile feature. Commands have no effect while compiliong
350 Control whether debug output about files/functions skipping is
353 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
354 Apply a command to some frames.
355 FLAG arguments allow to control what output to produce and how to handle
356 errors raised when applying COMMAND to a frame.
359 Apply a command to all threads (ignoring errors and empty output).
360 Shortcut for 'thread apply all -s COMMAND'.
363 Apply a command to all frames (ignoring errors and empty output).
364 Shortcut for 'frame apply all -s COMMAND'.
367 Apply a command to all frames of all threads (ignoring errors and empty
369 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
371 maint set dwarf unwinders (on|off)
372 maint show dwarf unwinders
373 Control whether DWARF unwinders can be used.
376 Display a list of open files for a process.
380 Changes to the "frame", "select-frame", and "info frame" CLI commands.
381 These commands all now take a frame specification which
382 is either a frame level, or one of the keywords 'level', 'address',
383 'function', or 'view' followed by a parameter. Selecting a frame by
384 address, or viewing a frame outside the current backtrace now
385 requires the use of a keyword. Selecting a frame by level is
386 unchanged. The MI comment "-stack-select-frame" is unchanged.
388 target remote FILENAME
389 target extended-remote FILENAME
390 If FILENAME is a Unix domain socket, GDB will attempt to connect
391 to this socket instead of opening FILENAME as a character device.
393 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
394 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
395 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
396 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
397 These commands can now print only the searched entities
398 matching the provided regexp(s), giving a condition
399 on the entity names or entity types. The flag -q disables
400 printing headers or informations messages.
406 These commands now determine the syntax for the shown entities
407 according to the language chosen by `set language'. In particular,
408 `set language auto' means to automatically choose the language of
411 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
412 The 'thread apply' command accepts new FLAG arguments.
413 FLAG arguments allow to control what output to produce and how to handle
414 errors raised when applying COMMAND to a thread.
416 set tui tab-width NCHARS
417 show tui tab-width NCHARS
418 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
420 set style enabled [on|off]
422 Enable or disable terminal styling. Styling is enabled by default
423 on most hosts, but disabled by default when in batch mode.
425 set style sources [on|off]
427 Enable or disable source code styling. Source code styling is
428 enabled by default, but only takes effect if styling in general is
429 enabled, and if GDB was linked with GNU Source Highlight.
431 set style filename foreground COLOR
432 set style filename background COLOR
433 set style filename intensity VALUE
434 Control the styling of file names.
436 set style function foreground COLOR
437 set style function background COLOR
438 set style function intensity VALUE
439 Control the styling of function names.
441 set style variable foreground COLOR
442 set style variable background COLOR
443 set style variable intensity VALUE
444 Control the styling of variable names.
446 set style address foreground COLOR
447 set style address background COLOR
448 set style address intensity VALUE
449 Control the styling of addresses.
453 ** The default version of the MI interpreter is now 3 (-i=mi3).
455 ** The '-data-disassemble' MI command now accepts an '-a' option to
456 disassemble the whole function surrounding the given program
457 counter value or function name. Support for this feature can be
458 verified by using the "-list-features" command, which should
459 contain "data-disassemble-a-option".
461 ** Command responses and notifications that include a frame now include
462 the frame's architecture in a new "arch" attribute.
464 ** The output of information about multi-location breakpoints (which is
465 syntactically incorrect in MI 2) has changed in MI 3. This affects
466 the following commands and events:
470 - =breakpoint-created
471 - =breakpoint-modified
473 The -fix-multi-location-breakpoint-output command can be used to enable
474 this behavior with previous MI versions.
476 * New native configurations
478 GNU/Linux/RISC-V riscv*-*-linux*
479 FreeBSD/riscv riscv*-*-freebsd*
483 GNU/Linux/RISC-V riscv*-*-linux*
485 CSKY GNU/LINUX csky*-*-linux
486 FreeBSD/riscv riscv*-*-freebsd*
488 GNU/Linux/OpenRISC or1k*-*-linux*
492 GDB no longer supports native debugging on versions of MS-Windows
497 ** GDB no longer supports Python versions less than 2.6.
499 ** The gdb.Inferior type has a new 'progspace' property, which is the program
500 space associated to that inferior.
502 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
503 of objfiles associated to that program space.
505 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
506 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
509 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
510 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
511 correct and did not work properly.
513 ** The gdb.Value type has a new constructor, which is used to construct a
514 gdb.Value from a Python buffer object and a gdb.Type.
520 Enable or disable the undefined behavior sanitizer. This is
521 disabled by default, but passing --enable-ubsan=yes or
522 --enable-ubsan=auto to configure will enable it. Enabling this can
523 cause a performance penalty. The undefined behavior sanitizer was
524 first introduced in GCC 4.9.
526 *** Changes in GDB 8.2
528 * The 'set disassembler-options' command now supports specifying options
531 * The 'symbol-file' command now accepts an '-o' option to add a relative
532 offset to all sections.
534 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
535 a relative offset to all sections, but it allows to override the load
536 address of individual sections using '-s'.
538 * The 'add-symbol-file' command no longer requires the second argument
539 (address of the text section).
541 * The endianness used with the 'set endian auto' mode in the absence of
542 an executable selected for debugging is now the last endianness chosen
543 either by one of the 'set endian big' and 'set endian little' commands
544 or by inferring from the last executable used, rather than the startup
547 * The pager now allows a "c" response, meaning to disable the pager
548 for the rest of the current command.
550 * The commands 'info variables/functions/types' now show the source line
551 numbers of symbol definitions when available.
553 * 'info proc' now works on running processes on FreeBSD systems and core
554 files created on FreeBSD systems.
556 * C expressions can now use _Alignof, and C++ expressions can now use
559 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
560 the vector length while the process is running.
566 Control display of debugging info regarding the FreeBSD native target.
568 set|show varsize-limit
569 This new setting allows the user to control the maximum size of Ada
570 objects being printed when those objects have a variable type,
571 instead of that maximum size being hardcoded to 65536 bytes.
573 set|show record btrace cpu
574 Controls the processor to be used for enabling errata workarounds for
577 maint check libthread-db
578 Run integrity checks on the current inferior's thread debugging
581 maint set check-libthread-db (on|off)
582 maint show check-libthread-db
583 Control whether to run integrity checks on inferior specific thread
584 debugging libraries as they are loaded. The default is not to
589 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
591 ** The commands attached to a breakpoint can be set by assigning to
592 the breakpoint's "commands" field.
594 ** gdb.execute can now execute multi-line gdb commands.
596 ** The new functions gdb.convenience_variable and
597 gdb.set_convenience_variable can be used to get and set the value
598 of convenience variables.
600 ** A gdb.Parameter will no longer print the "set" help text on an
601 ordinary "set"; instead by default a "set" will be silent unless
602 the get_set_string method returns a non-empty string.
606 RiscV ELF riscv*-*-elf
608 * Removed targets and native configurations
610 m88k running OpenBSD m88*-*-openbsd*
611 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
612 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
613 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
615 * Aarch64/Linux hardware watchpoints improvements
617 Hardware watchpoints on unaligned addresses are now properly
618 supported when running Linux kernel 4.10 or higher: read and access
619 watchpoints are no longer spuriously missed, and all watchpoints
620 lengths between 1 and 8 bytes are supported. On older kernels,
621 watchpoints set on unaligned addresses are no longer missed, with
622 the tradeoff that there is a possibility of false hits being
627 --enable-codesign=CERT
628 This can be used to invoke "codesign -s CERT" after building gdb.
629 This option is useful on macOS, where code signing is required for
630 gdb to work properly.
632 --disable-gdbcli has been removed
633 This is now silently accepted, but does nothing.
635 *** Changes in GDB 8.1
637 * GDB now supports dynamically creating arbitrary register groups specified
638 in XML target descriptions. This allows for finer grain grouping of
639 registers on systems with a large amount of registers.
641 * The 'ptype' command now accepts a '/o' flag, which prints the
642 offsets and sizes of fields in a struct, like the pahole(1) tool.
644 * New "--readnever" command line option instructs GDB to not read each
645 symbol file's symbolic debug information. This makes startup faster
646 but at the expense of not being able to perform symbolic debugging.
647 This option is intended for use cases where symbolic debugging will
648 not be used, e.g., when you only need to dump the debuggee's core.
650 * GDB now uses the GNU MPFR library, if available, to emulate target
651 floating-point arithmetic during expression evaluation when the target
652 uses different floating-point formats than the host. At least version
653 3.1 of GNU MPFR is required.
655 * GDB now supports access to the guarded-storage-control registers and the
656 software-based guarded-storage broadcast control registers on IBM z14.
658 * On Unix systems, GDB now supports transmitting environment variables
659 that are to be set or unset to GDBserver. These variables will
660 affect the environment to be passed to the remote inferior.
662 To inform GDB of environment variables that are to be transmitted to
663 GDBserver, use the "set environment" command. Only user set
664 environment variables are sent to GDBserver.
666 To inform GDB of environment variables that are to be unset before
667 the remote inferior is started by the GDBserver, use the "unset
668 environment" command.
670 * Completion improvements
672 ** GDB can now complete function parameters in linespecs and
673 explicit locations without quoting. When setting breakpoints,
674 quoting around functions names to help with TAB-completion is
675 generally no longer necessary. For example, this now completes
678 (gdb) b function(in[TAB]
679 (gdb) b function(int)
681 Related, GDB is no longer confused with completing functions in
682 C++ anonymous namespaces:
685 (gdb) b (anonymous namespace)::[TAB][TAB]
686 (anonymous namespace)::a_function()
687 (anonymous namespace)::b_function()
689 ** GDB now has much improved linespec and explicit locations TAB
690 completion support, that better understands what you're
691 completing and offers better suggestions. For example, GDB no
692 longer offers data symbols as possible completions when you're
693 setting a breakpoint.
695 ** GDB now TAB-completes label symbol names.
697 ** The "complete" command now mimics TAB completion accurately.
699 * New command line options (gcore)
702 Dump all memory mappings.
704 * Breakpoints on C++ functions are now set on all scopes by default
706 By default, breakpoints on functions/methods are now interpreted as
707 specifying all functions with the given name ignoring missing
708 leading scopes (namespaces and classes).
710 For example, assuming a C++ program with symbols named:
715 both commands "break func()" and "break B::func()" set a breakpoint
718 You can use the new flag "-qualified" to override this. This makes
719 GDB interpret the specified function name as a complete
720 fully-qualified name instead. For example, using the same C++
721 program, the "break -q B::func" command sets a breakpoint on
722 "B::func", only. A parameter has been added to the Python
723 gdb.Breakpoint constructor to achieve the same result when creating
724 a breakpoint from Python.
726 * Breakpoints on functions marked with C++ ABI tags
728 GDB can now set breakpoints on functions marked with C++ ABI tags
729 (e.g., [abi:cxx11]). See here for a description of ABI tags:
730 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
732 Functions with a C++11 abi tag are demangled/displayed like this:
734 function[abi:cxx11](int)
737 You can now set a breakpoint on such functions simply as if they had
740 (gdb) b function(int)
742 Or if you need to disambiguate between tags, like:
744 (gdb) b function[abi:other_tag](int)
746 Tab completion was adjusted accordingly as well.
750 ** New events gdb.new_inferior, gdb.inferior_deleted, and
751 gdb.new_thread are emitted. See the manual for further
752 description of these.
754 ** A new function, "gdb.rbreak" has been added to the Python API.
755 This function allows the setting of a large number of breakpoints
756 via a regex pattern in Python. See the manual for further details.
758 ** Python breakpoints can now accept explicit locations. See the
759 manual for a further description of this feature.
762 * New features in the GDB remote stub, GDBserver
764 ** GDBserver is now able to start inferior processes with a
765 specified initial working directory.
767 The user can set the desired working directory to be used from
768 GDB using the new "set cwd" command.
770 ** New "--selftest" command line option runs some GDBserver self
771 tests. These self tests are disabled in releases.
773 ** On Unix systems, GDBserver now does globbing expansion and variable
774 substitution in inferior command line arguments.
776 This is done by starting inferiors using a shell, like GDB does.
777 See "set startup-with-shell" in the user manual for how to disable
778 this from GDB when using "target extended-remote". When using
779 "target remote", you can disable the startup with shell by using the
780 new "--no-startup-with-shell" GDBserver command line option.
782 ** On Unix systems, GDBserver now supports receiving environment
783 variables that are to be set or unset from GDB. These variables
784 will affect the environment to be passed to the inferior.
786 * When catching an Ada exception raised with a message, GDB now prints
787 the message in the catchpoint hit notification. In GDB/MI mode, that
788 information is provided as an extra field named "exception-message"
789 in the *stopped notification.
791 * Trait objects can now be inspected When debugging Rust code. This
792 requires compiler support which will appear in Rust 1.24.
796 QEnvironmentHexEncoded
797 Inform GDBserver of an environment variable that is to be passed to
798 the inferior when starting it.
801 Inform GDBserver of an environment variable that is to be unset
802 before starting the remote inferior.
805 Inform GDBserver that the environment should be reset (i.e.,
806 user-set environment variables should be unset).
809 Indicates whether the inferior must be started with a shell or not.
812 Tell GDBserver that the inferior to be started should use a specific
815 * The "maintenance print c-tdesc" command now takes an optional
816 argument which is the file name of XML target description.
818 * The "maintenance selftest" command now takes an optional argument to
819 filter the tests to be run.
821 * The "enable", and "disable" commands now accept a range of
822 breakpoint locations, e.g. "enable 1.3-5".
827 Set and show the current working directory for the inferior.
830 Set and show compilation command used for compiling and injecting code
831 with the 'compile' commands.
833 set debug separate-debug-file
834 show debug separate-debug-file
835 Control the display of debug output about separate debug file search.
837 set dump-excluded-mappings
838 show dump-excluded-mappings
839 Control whether mappings marked with the VM_DONTDUMP flag should be
840 dumped when generating a core file.
843 List the registered selftests.
846 Start the debugged program stopping at the first instruction.
849 Control display of debugging messages related to OpenRISC targets.
851 set|show print type nested-type-limit
852 Set and show the limit of nesting level for nested types that the
853 type printer will show.
855 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
858 * Safer/improved support for debugging with no debug info
860 GDB no longer assumes functions with no debug information return
863 This means that GDB now refuses to call such functions unless you
864 tell it the function's type, by either casting the call to the
865 declared return type, or by casting the function to a function
866 pointer of the right type, and calling that:
868 (gdb) p getenv ("PATH")
869 'getenv' has unknown return type; cast the call to its declared return type
870 (gdb) p (char *) getenv ("PATH")
871 $1 = 0x7fffffffe "/usr/local/bin:/"...
872 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
873 $2 = 0x7fffffffe "/usr/local/bin:/"...
875 Similarly, GDB no longer assumes that global variables with no debug
876 info have type 'int', and refuses to print the variable's value
877 unless you tell it the variable's type:
880 'var' has unknown type; cast it to its declared type
884 * New native configurations
886 FreeBSD/aarch64 aarch64*-*-freebsd*
887 FreeBSD/arm arm*-*-freebsd*
891 FreeBSD/aarch64 aarch64*-*-freebsd*
892 FreeBSD/arm arm*-*-freebsd*
893 OpenRISC ELF or1k*-*-elf
895 * Removed targets and native configurations
897 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
899 *** Changes in GDB 8.0
901 * GDB now supports access to the PKU register on GNU/Linux. The register is
902 added by the Memory Protection Keys for Userspace feature which will be
903 available in future Intel CPUs.
905 * GDB now supports C++11 rvalue references.
909 ** New functions to start, stop and access a running btrace recording.
910 ** Rvalue references are now supported in gdb.Type.
912 * GDB now supports recording and replaying rdrand and rdseed Intel 64
915 * Building GDB and GDBserver now requires a C++11 compiler.
917 For example, GCC 4.8 or later.
919 It is no longer possible to build GDB or GDBserver with a C
920 compiler. The --disable-build-with-cxx configure option has been
923 * Building GDB and GDBserver now requires GNU make >= 3.81.
925 It is no longer supported to build GDB or GDBserver with another
926 implementation of the make program or an earlier version of GNU make.
928 * Native debugging on MS-Windows supports command-line redirection
930 Command-line arguments used for starting programs on MS-Windows can
931 now include redirection symbols supported by native Windows shells,
932 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
933 as "run", "start", and "set args", as well as the corresponding MI
936 * Support for thread names on MS-Windows.
938 GDB now catches and handles the special exception that programs
939 running on MS-Windows use to assign names to threads in the
942 * Support for Java programs compiled with gcj has been removed.
944 * User commands now accept an unlimited number of arguments.
945 Previously, only up to 10 was accepted.
947 * The "eval" command now expands user-defined command arguments.
949 This makes it easier to process a variable number of arguments:
954 eval "print $arg%d", $i
959 * Target descriptions can now describe registers for sparc32 and sparc64.
961 * GDB now supports DWARF version 5 (debug information format).
962 Its .debug_names index is not yet supported.
964 * New native configurations
966 FreeBSD/mips mips*-*-freebsd
970 Synopsys ARC arc*-*-elf32
971 FreeBSD/mips mips*-*-freebsd
973 * Removed targets and native configurations
975 Alpha running FreeBSD alpha*-*-freebsd*
976 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
981 Erases all the flash memory regions reported by the target.
983 maint print arc arc-instruction address
984 Print internal disassembler information about instruction at a given address.
988 set disassembler-options
989 show disassembler-options
990 Controls the passing of target specific information to the disassembler.
991 If it is necessary to specify more than one disassembler option then
992 multiple options can be placed together into a comma separated list.
993 The default value is the empty string. Currently, the only supported
994 targets are ARM, PowerPC and S/390.
999 Erases all the flash memory regions reported by the target. This is
1000 equivalent to the CLI command flash-erase.
1002 -file-list-shared-libraries
1003 List the shared libraries in the program. This is
1004 equivalent to the CLI command "info shared".
1007 Catchpoints stopping the program when Ada exceptions are
1008 handled. This is equivalent to the CLI command "catch handlers".
1010 *** Changes in GDB 7.12
1012 * GDB and GDBserver now build with a C++ compiler by default.
1014 The --enable-build-with-cxx configure option is now enabled by
1015 default. One must now explicitly configure with
1016 --disable-build-with-cxx in order to build with a C compiler. This
1017 option will be removed in a future release.
1019 * GDBserver now supports recording btrace without maintaining an active
1022 * GDB now supports a negative repeat count in the 'x' command to examine
1023 memory backward from the given address. For example:
1026 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1027 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1028 (gdb) x/-5i 0x0000000000400580
1029 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1030 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1031 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1032 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1033 0x40057b <main(int, char**)+25>:
1034 callq 0x400536 <Func1(int, char const*)>
1036 * Fortran: Support structures with fields of dynamic types and
1037 arrays of dynamic types.
1039 * The symbol dumping maintenance commands have new syntax.
1040 maint print symbols [-pc address] [--] [filename]
1041 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1042 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1043 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1044 maint print msymbols [-objfile objfile] [--] [filename]
1046 * GDB now supports multibit bitfields and enums in target register
1049 * New Python-based convenience function $_as_string(val), which returns
1050 the textual representation of a value. This function is especially
1051 useful to obtain the text label of an enum value.
1053 * Intel MPX bound violation handling.
1055 Segmentation faults caused by a Intel MPX boundary violation
1056 now display the kind of violation (upper or lower), the memory
1057 address accessed and the memory bounds, along with the usual
1058 signal received and code location.
1062 Program received signal SIGSEGV, Segmentation fault
1063 Upper bound violation while accessing address 0x7fffffffc3b3
1064 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1065 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1067 * Rust language support.
1068 GDB now supports debugging programs written in the Rust programming
1069 language. See https://www.rust-lang.org/ for more information about
1072 * Support for running interpreters on specified input/output devices
1074 GDB now supports a new mechanism that allows frontends to provide
1075 fully featured GDB console views, as a better alternative to
1076 building such views on top of the "-interpreter-exec console"
1077 command. See the new "new-ui" command below. With that command,
1078 frontends can now start GDB in the traditional command-line mode
1079 running in an embedded terminal emulator widget, and create a
1080 separate MI interpreter running on a specified i/o device. In this
1081 way, GDB handles line editing, history, tab completion, etc. in the
1082 console all by itself, and the GUI uses the separate MI interpreter
1083 for its own control and synchronization, invisible to the command
1086 * The "catch syscall" command catches groups of related syscalls.
1088 The "catch syscall" command now supports catching a group of related
1089 syscalls using the 'group:' or 'g:' prefix.
1094 skip -gfile file-glob-pattern
1095 skip -function function
1096 skip -rfunction regular-expression
1097 A generalized form of the skip command, with new support for
1098 glob-style file names and regular expressions for function names.
1099 Additionally, a file spec and a function spec may now be combined.
1101 maint info line-table REGEXP
1102 Display the contents of GDB's internal line table data struture.
1105 Run any GDB unit tests that were compiled in.
1108 Start a new user interface instance running INTERP as interpreter,
1109 using the TTY file for input/output.
1113 ** gdb.Breakpoint objects have a new attribute "pending", which
1114 indicates whether the breakpoint is pending.
1115 ** Three new breakpoint-related events have been added:
1116 gdb.breakpoint_created, gdb.breakpoint_modified, and
1117 gdb.breakpoint_deleted.
1119 signal-event EVENTID
1120 Signal ("set") the given MS-Windows event object. This is used in
1121 conjunction with the Windows JIT debugging (AeDebug) support, where
1122 the OS suspends a crashing process until a debugger can attach to
1123 it. Resuming the crashing process, in order to debug it, is done by
1124 signalling an event.
1126 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1127 was added in GDBserver, including JIT compiling fast tracepoint's
1128 conditional expression bytecode into native code.
1130 * Support for various remote target protocols and ROM monitors has
1133 target m32rsdi Remote M32R debugging over SDI
1134 target mips MIPS remote debugging protocol
1135 target pmon PMON ROM monitor
1136 target ddb NEC's DDB variant of PMON for Vr4300
1137 target rockhopper NEC RockHopper variant of PMON
1138 target lsi LSI variant of PMO
1140 * Support for tracepoints and fast tracepoints on powerpc-linux,
1141 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1142 including JIT compiling fast tracepoint's conditional expression
1143 bytecode into native code.
1145 * MI async record =record-started now includes the method and format used for
1146 recording. For example:
1148 =record-started,thread-group="i1",method="btrace",format="bts"
1150 * MI async record =thread-selected now includes the frame field. For example:
1152 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1156 Andes NDS32 nds32*-*-elf
1158 *** Changes in GDB 7.11
1160 * GDB now supports debugging kernel-based threads on FreeBSD.
1162 * Per-inferior thread numbers
1164 Thread numbers are now per inferior instead of global. If you're
1165 debugging multiple inferiors, GDB displays thread IDs using a
1166 qualified INF_NUM.THR_NUM form. For example:
1170 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1171 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1172 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1173 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1175 As consequence, thread numbers as visible in the $_thread
1176 convenience variable and in Python's InferiorThread.num attribute
1177 are no longer unique between inferiors.
1179 GDB now maintains a second thread ID per thread, referred to as the
1180 global thread ID, which is the new equivalent of thread numbers in
1181 previous releases. See also $_gthread below.
1183 For backwards compatibility, MI's thread IDs always refer to global
1186 * Commands that accept thread IDs now accept the qualified
1187 INF_NUM.THR_NUM form as well. For example:
1190 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1193 * In commands that accept a list of thread IDs, you can now refer to
1194 all threads of an inferior using a star wildcard. GDB accepts
1195 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1196 refer to all threads of the current inferior. For example, "info
1199 * You can use "info threads -gid" to display the global thread ID of
1202 * The new convenience variable $_gthread holds the global number of
1205 * The new convenience variable $_inferior holds the number of the
1208 * GDB now displays the ID and name of the thread that hit a breakpoint
1209 or received a signal, if your program is multi-threaded. For
1212 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1213 Thread 1 "main" received signal SIGINT, Interrupt.
1215 * Record btrace now supports non-stop mode.
1217 * Support for tracepoints on aarch64-linux was added in GDBserver.
1219 * The 'record instruction-history' command now indicates speculative execution
1220 when using the Intel Processor Trace recording format.
1222 * GDB now allows users to specify explicit locations, bypassing
1223 the linespec parser. This feature is also available to GDB/MI
1226 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1227 GDB now is able to debug both AArch64 applications and ARM applications
1230 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1231 including JIT compiling fast tracepoint's conditional expression bytecode
1234 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1236 * "info threads", "info inferiors", "info display", "info checkpoints"
1237 and "maint info program-spaces" now list the corresponding items in
1238 ascending ID order, for consistency with all other "info" commands.
1240 * In Ada, the overloads selection menu has been enhanced to display the
1241 parameter types and the return types for the matching overloaded subprograms.
1245 maint set target-non-stop (on|off|auto)
1246 maint show target-non-stop
1247 Control whether GDB targets always operate in non-stop mode even if
1248 "set non-stop" is "off". The default is "auto", meaning non-stop
1249 mode is enabled if supported by the target.
1251 maint set bfd-sharing
1252 maint show bfd-sharing
1253 Control the reuse of bfd objects.
1256 show debug bfd-cache
1257 Control display of debugging info regarding bfd caching.
1261 Control display of debugging info regarding FreeBSD threads.
1263 set remote multiprocess-extensions-packet
1264 show remote multiprocess-extensions-packet
1265 Set/show the use of the remote protocol multiprocess extensions.
1267 set remote thread-events
1268 show remote thread-events
1269 Set/show the use of thread create/exit events.
1271 set ada print-signatures on|off
1272 show ada print-signatures"
1273 Control whether parameter types and return types are displayed in overloads
1274 selection menus. It is activaled (@code{on}) by default.
1278 Controls the maximum size of memory, in bytes, that GDB will
1279 allocate for value contents. Prevents incorrect programs from
1280 causing GDB to allocate overly large buffers. Default is 64k.
1282 * The "disassemble" command accepts a new modifier: /s.
1283 It prints mixed source+disassembly like /m with two differences:
1284 - disassembled instructions are now printed in program order, and
1285 - and source for all relevant files is now printed.
1286 The "/m" option is now considered deprecated: its "source-centric"
1287 output hasn't proved useful in practice.
1289 * The "record instruction-history" command accepts a new modifier: /s.
1290 It behaves exactly like /m and prints mixed source+disassembly.
1292 * The "set scheduler-locking" command supports a new mode "replay".
1293 It behaves like "off" in record mode and like "on" in replay mode.
1295 * Support for various ROM monitors has been removed:
1297 target dbug dBUG ROM monitor for Motorola ColdFire
1298 target picobug Motorola picobug monitor
1299 target dink32 DINK32 ROM monitor for PowerPC
1300 target m32r Renesas M32R/D ROM monitor
1301 target mon2000 mon2000 ROM monitor
1302 target ppcbug PPCBUG ROM monitor for PowerPC
1304 * Support for reading/writing memory and extracting values on architectures
1305 whose memory is addressable in units of any integral multiple of 8 bits.
1308 Allows to break when an Ada exception is handled.
1310 * New remote packets
1313 Indicates that an exec system call was executed.
1315 exec-events feature in qSupported
1316 The qSupported packet allows GDB to request support for exec
1317 events using the new 'gdbfeature' exec-event, and the qSupported
1318 response can contain the corresponding 'stubfeature'. Set and
1319 show commands can be used to display whether these features are enabled.
1322 Equivalent to interrupting with the ^C character, but works in
1325 thread created stop reason (T05 create:...)
1326 Indicates that the thread was just created and is stopped at entry.
1328 thread exit stop reply (w exitcode;tid)
1329 Indicates that the thread has terminated.
1332 Enables/disables thread create and exit event reporting. For
1333 example, this is used in non-stop mode when GDB stops a set of
1334 threads and synchronously waits for the their corresponding stop
1335 replies. Without exit events, if one of the threads exits, GDB
1336 would hang forever not knowing that it should no longer expect a
1337 stop for that same thread.
1340 Indicates that there are no resumed threads left in the target (all
1341 threads are stopped). The remote stub reports support for this stop
1342 reply to GDB's qSupported query.
1345 Enables/disables catching syscalls from the inferior process.
1346 The remote stub reports support for this packet to GDB's qSupported query.
1348 syscall_entry stop reason
1349 Indicates that a syscall was just called.
1351 syscall_return stop reason
1352 Indicates that a syscall just returned.
1354 * Extended-remote exec events
1356 ** GDB now has support for exec events on extended-remote Linux targets.
1357 For such targets with Linux kernels 2.5.46 and later, this enables
1358 follow-exec-mode and exec catchpoints.
1360 set remote exec-event-feature-packet
1361 show remote exec-event-feature-packet
1362 Set/show the use of the remote exec event feature.
1364 * Thread names in remote protocol
1366 The reply to qXfer:threads:read may now include a name attribute for each
1369 * Target remote mode fork and exec events
1371 ** GDB now has support for fork and exec events on target remote mode
1372 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1373 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1374 fork and exec catchpoints.
1376 * Remote syscall events
1378 ** GDB now has support for catch syscall on remote Linux targets,
1379 currently enabled on x86/x86_64 architectures.
1381 set remote catch-syscall-packet
1382 show remote catch-syscall-packet
1383 Set/show the use of the remote catch syscall feature.
1387 ** The -var-set-format command now accepts the zero-hexadecimal
1388 format. It outputs data in hexadecimal format with zero-padding on the
1393 ** gdb.InferiorThread objects have a new attribute "global_num",
1394 which refers to the thread's global thread ID. The existing
1395 "num" attribute now refers to the thread's per-inferior number.
1396 See "Per-inferior thread numbers" above.
1397 ** gdb.InferiorThread objects have a new attribute "inferior", which
1398 is the Inferior object the thread belongs to.
1400 *** Changes in GDB 7.10
1402 * Support for process record-replay and reverse debugging on aarch64*-linux*
1403 targets has been added. GDB now supports recording of A64 instruction set
1404 including advance SIMD instructions.
1406 * Support for Sun's version of the "stabs" debug file format has been removed.
1408 * GDB now honors the content of the file /proc/PID/coredump_filter
1409 (PID is the process ID) on GNU/Linux systems. This file can be used
1410 to specify the types of memory mappings that will be included in a
1411 corefile. For more information, please refer to the manual page of
1412 "core(5)". GDB also has a new command: "set use-coredump-filter
1413 on|off". It allows to set whether GDB will read the content of the
1414 /proc/PID/coredump_filter file when generating a corefile.
1416 * The "info os" command on GNU/Linux can now display information on
1418 "info os cpus" Listing of all cpus/cores on the system
1420 * GDB has two new commands: "set serial parity odd|even|none" and
1421 "show serial parity". These allows to set or show parity for the
1424 * The "info source" command now displays the producer string if it was
1425 present in the debug info. This typically includes the compiler version
1426 and may include things like its command line arguments.
1428 * The "info dll", an alias of the "info sharedlibrary" command,
1429 is now available on all platforms.
1431 * Directory names supplied to the "set sysroot" commands may be
1432 prefixed with "target:" to tell GDB to access shared libraries from
1433 the target system, be it local or remote. This replaces the prefix
1434 "remote:". The default sysroot has been changed from "" to
1435 "target:". "remote:" is automatically converted to "target:" for
1436 backward compatibility.
1438 * The system root specified by "set sysroot" will be prepended to the
1439 filename of the main executable (if reported to GDB as absolute by
1440 the operating system) when starting processes remotely, and when
1441 attaching to already-running local or remote processes.
1443 * GDB now supports automatic location and retrieval of executable
1444 files from remote targets. Remote debugging can now be initiated
1445 using only a "target remote" or "target extended-remote" command
1446 (no "set sysroot" or "file" commands are required). See "New remote
1449 * The "dump" command now supports verilog hex format.
1451 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1453 * On GNU/Linux, GDB and gdbserver are now able to access executable
1454 and shared library files without a "set sysroot" command when
1455 attaching to processes running in different mount namespaces from
1456 the debugger. This makes it possible to attach to processes in
1457 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1458 See "New remote packets" below.
1460 * The "tui reg" command now provides completion for all of the
1461 available register groups, including target specific groups.
1463 * The HISTSIZE environment variable is no longer read when determining
1464 the size of GDB's command history. GDB now instead reads the dedicated
1465 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1466 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1471 ** Memory ports can now be unbuffered.
1475 ** gdb.Objfile objects have a new attribute "username",
1476 which is the name of the objfile as specified by the user,
1477 without, for example, resolving symlinks.
1478 ** You can now write frame unwinders in Python.
1479 ** gdb.Type objects have a new method "optimized_out",
1480 returning optimized out gdb.Value instance of this type.
1481 ** gdb.Value objects have new methods "reference_value" and
1482 "const_value" which return a reference to the value and a
1483 "const" version of the value respectively.
1487 maint print symbol-cache
1488 Print the contents of the symbol cache.
1490 maint print symbol-cache-statistics
1491 Print statistics of symbol cache usage.
1493 maint flush-symbol-cache
1494 Flush the contents of the symbol cache.
1498 Start branch trace recording using Branch Trace Store (BTS) format.
1501 Evaluate expression by using the compiler and print result.
1505 Explicit commands for enabling and disabling tui mode.
1508 set mpx bound on i386 and amd64
1509 Support for bound table investigation on Intel MPX enabled applications.
1513 Start branch trace recording using Intel Processor Trace format.
1516 Print information about branch tracing internals.
1518 maint btrace packet-history
1519 Print the raw branch tracing data.
1521 maint btrace clear-packet-history
1522 Discard the stored raw branch tracing data.
1525 Discard all branch tracing data. It will be fetched and processed
1526 anew by the next "record" command.
1531 Renamed from "set debug dwarf2-die".
1532 show debug dwarf-die
1533 Renamed from "show debug dwarf2-die".
1535 set debug dwarf-read
1536 Renamed from "set debug dwarf2-read".
1537 show debug dwarf-read
1538 Renamed from "show debug dwarf2-read".
1540 maint set dwarf always-disassemble
1541 Renamed from "maint set dwarf2 always-disassemble".
1542 maint show dwarf always-disassemble
1543 Renamed from "maint show dwarf2 always-disassemble".
1545 maint set dwarf max-cache-age
1546 Renamed from "maint set dwarf2 max-cache-age".
1547 maint show dwarf max-cache-age
1548 Renamed from "maint show dwarf2 max-cache-age".
1550 set debug dwarf-line
1551 show debug dwarf-line
1552 Control display of debugging info regarding DWARF line processing.
1555 show max-completions
1556 Set the maximum number of candidates to be considered during
1557 completion. The default value is 200. This limit allows GDB
1558 to avoid generating large completion lists, the computation of
1559 which can cause the debugger to become temporarily unresponsive.
1561 set history remove-duplicates
1562 show history remove-duplicates
1563 Control the removal of duplicate history entries.
1565 maint set symbol-cache-size
1566 maint show symbol-cache-size
1567 Control the size of the symbol cache.
1569 set|show record btrace bts buffer-size
1570 Set and show the size of the ring buffer used for branch tracing in
1572 The obtained size may differ from the requested size. Use "info
1573 record" to see the obtained buffer size.
1575 set debug linux-namespaces
1576 show debug linux-namespaces
1577 Control display of debugging info regarding Linux namespaces.
1579 set|show record btrace pt buffer-size
1580 Set and show the size of the ring buffer used for branch tracing in
1581 Intel Processor Trace format.
1582 The obtained size may differ from the requested size. Use "info
1583 record" to see the obtained buffer size.
1585 maint set|show btrace pt skip-pad
1586 Set and show whether PAD packets are skipped when computing the
1589 * The command 'thread apply all' can now support new option '-ascending'
1590 to call its specified command for all threads in ascending order.
1592 * Python/Guile scripting
1594 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1595 special section named `.debug_gdb_scripts'.
1597 * New remote packets
1599 qXfer:btrace-conf:read
1600 Return the branch trace configuration for the current thread.
1602 Qbtrace-conf:bts:size
1603 Set the requested ring buffer size for branch tracing in BTS format.
1606 Enable Intel Procesor Trace-based branch tracing for the current
1607 process. The remote stub reports support for this packet to GDB's
1610 Qbtrace-conf:pt:size
1611 Set the requested ring buffer size for branch tracing in Intel Processor
1615 Indicates a memory breakpoint instruction was executed, irrespective
1616 of whether it was GDB that planted the breakpoint or the breakpoint
1617 is hardcoded in the program. This is required for correct non-stop
1621 Indicates the target stopped for a hardware breakpoint. This is
1622 required for correct non-stop mode operation.
1625 Return information about files on the remote system.
1627 qXfer:exec-file:read
1628 Return the full absolute name of the file that was executed to
1629 create a process running on the remote system.
1632 Select the filesystem on which vFile: operations with filename
1633 arguments will operate. This is required for GDB to be able to
1634 access files on remote targets where the remote stub does not
1635 share a common filesystem with the inferior(s).
1638 Indicates that a fork system call was executed.
1641 Indicates that a vfork system call was executed.
1643 vforkdone stop reason
1644 Indicates that a vfork child of the specified process has executed
1645 an exec or exit, allowing the vfork parent to resume execution.
1647 fork-events and vfork-events features in qSupported
1648 The qSupported packet allows GDB to request support for fork and
1649 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1650 and the qSupported response can contain the corresponding
1651 'stubfeatures'. Set and show commands can be used to display
1652 whether these features are enabled.
1654 * Extended-remote fork events
1656 ** GDB now has support for fork events on extended-remote Linux
1657 targets. For targets with Linux kernels 2.5.60 and later, this
1658 enables follow-fork-mode and detach-on-fork for both fork and
1659 vfork, as well as fork and vfork catchpoints.
1661 * The info record command now shows the recording format and the
1662 branch tracing configuration for the current thread when using
1663 the btrace record target.
1664 For the BTS format, it shows the ring buffer size.
1666 * GDB now has support for DTrace USDT (Userland Static Defined
1667 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1669 * GDB now supports access to vector registers on S/390 GNU/Linux
1672 * Removed command line options
1674 -xdb HP-UX XDB compatibility mode.
1676 * Removed targets and native configurations
1678 HP/PA running HP-UX hppa*-*-hpux*
1679 Itanium running HP-UX ia64-*-hpux*
1681 * New configure options
1684 This configure option allows the user to build GDB with support for
1685 Intel Processor Trace (default: auto). This requires libipt.
1687 --with-libipt-prefix=PATH
1688 Specify the path to the version of libipt that GDB should use.
1689 $PATH/include should contain the intel-pt.h header and
1690 $PATH/lib should contain the libipt.so library.
1692 *** Changes in GDB 7.9.1
1696 ** Xmethods can now specify a result type.
1698 *** Changes in GDB 7.9
1700 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1704 ** You can now access frame registers from Python scripts.
1705 ** New attribute 'producer' for gdb.Symtab objects.
1706 ** gdb.Objfile objects have a new attribute "progspace",
1707 which is the gdb.Progspace object of the containing program space.
1708 ** gdb.Objfile objects have a new attribute "owner".
1709 ** gdb.Objfile objects have a new attribute "build_id",
1710 which is the build ID generated when the file was built.
1711 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1712 ** A new event "gdb.clear_objfiles" has been added, triggered when
1713 selecting a new file to debug.
1714 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1715 ** New function gdb.lookup_objfile.
1717 New events which are triggered when GDB modifies the state of the
1720 ** gdb.events.inferior_call_pre: Function call is about to be made.
1721 ** gdb.events.inferior_call_post: Function call has just been made.
1722 ** gdb.events.memory_changed: A memory location has been altered.
1723 ** gdb.events.register_changed: A register has been altered.
1725 * New Python-based convenience functions:
1727 ** $_caller_is(name [, number_of_frames])
1728 ** $_caller_matches(regexp [, number_of_frames])
1729 ** $_any_caller_is(name [, number_of_frames])
1730 ** $_any_caller_matches(regexp [, number_of_frames])
1732 * GDB now supports the compilation and injection of source code into
1733 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1734 to compile the source code to object code, and if successful, inject
1735 and execute that code within the current context of the inferior.
1736 Currently the C language is supported. The commands used to
1737 interface with this new feature are:
1739 compile code [-raw|-r] [--] [source code]
1740 compile file [-raw|-r] filename
1744 demangle [-l language] [--] name
1745 Demangle "name" in the specified language, or the current language
1746 if elided. This command is renamed from the "maint demangle" command.
1747 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1748 as "maint demangler-warning".
1750 queue-signal signal-name-or-number
1751 Queue a signal to be delivered to the thread when it is resumed.
1753 add-auto-load-scripts-directory directory
1754 Add entries to the list of directories from which to load auto-loaded
1757 maint print user-registers
1758 List all currently available "user" registers.
1760 compile code [-r|-raw] [--] [source code]
1761 Compile, inject, and execute in the inferior the executable object
1762 code produced by compiling the provided source code.
1764 compile file [-r|-raw] filename
1765 Compile and inject into the inferior the executable object code
1766 produced by compiling the source code stored in the filename
1769 * On resume, GDB now always passes the signal the program had stopped
1770 for to the thread the signal was sent to, even if the user changed
1771 threads before resuming. Previously GDB would often (but not
1772 always) deliver the signal to the thread that happens to be current
1775 * Conversely, the "signal" command now consistently delivers the
1776 requested signal to the current thread. GDB now asks for
1777 confirmation if the program had stopped for a signal and the user
1778 switched threads meanwhile.
1780 * "breakpoint always-inserted" modes "off" and "auto" merged.
1782 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1783 won't remove breakpoints from the target until all threads stop,
1784 even in non-stop mode. The "auto" mode has been removed, and "off"
1785 is now the default mode.
1789 set debug symbol-lookup
1790 show debug symbol-lookup
1791 Control display of debugging info regarding symbol lookup.
1795 ** The -list-thread-groups command outputs an exit-code field for
1796 inferiors that have exited.
1800 MIPS SDE mips*-sde*-elf*
1804 Support for these obsolete configurations has been removed.
1806 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1807 SGI Irix-5.x mips-*-irix5*
1808 SGI Irix-6.x mips-*-irix6*
1809 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1810 VAX running Ultrix vax-*-ultrix*
1812 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1813 and "assf"), have been removed. Use the "sharedlibrary" command, or
1814 its alias "share", instead.
1816 *** Changes in GDB 7.8
1818 * New command line options
1821 This is an alias for the --data-directory option.
1823 * GDB supports printing and modifying of variable length automatic arrays
1824 as specified in ISO C99.
1826 * The ARM simulator now supports instruction level tracing
1827 with or without disassembly.
1831 GDB now has support for scripting using Guile. Whether this is
1832 available is determined at configure time.
1833 Guile version 2.0 or greater is required.
1834 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1836 * New commands (for set/show, see "New options" below)
1840 Invoke CODE by passing it to the Guile interpreter.
1844 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1846 info auto-load guile-scripts [regexp]
1847 Print the list of automatically loaded Guile scripts.
1849 * The source command is now capable of sourcing Guile scripts.
1850 This feature is dependent on the debugger being built with Guile support.
1854 set print symbol-loading (off|brief|full)
1855 show print symbol-loading
1856 Control whether to print informational messages when loading symbol
1857 information for a file. The default is "full", but when debugging
1858 programs with large numbers of shared libraries the amount of output
1859 becomes less useful.
1861 set guile print-stack (none|message|full)
1862 show guile print-stack
1863 Show a stack trace when an error is encountered in a Guile script.
1865 set auto-load guile-scripts (on|off)
1866 show auto-load guile-scripts
1867 Control auto-loading of Guile script files.
1869 maint ada set ignore-descriptive-types (on|off)
1870 maint ada show ignore-descriptive-types
1871 Control whether the debugger should ignore descriptive types in Ada
1872 programs. The default is not to ignore the descriptive types. See
1873 the user manual for more details on descriptive types and the intended
1874 usage of this option.
1876 set auto-connect-native-target
1878 Control whether GDB is allowed to automatically connect to the
1879 native target for the run, attach, etc. commands when not connected
1880 to any target yet. See also "target native" below.
1882 set record btrace replay-memory-access (read-only|read-write)
1883 show record btrace replay-memory-access
1884 Control what memory accesses are allowed during replay.
1886 maint set target-async (on|off)
1887 maint show target-async
1888 This controls whether GDB targets operate in synchronous or
1889 asynchronous mode. Normally the default is asynchronous, if it is
1890 available; but this can be changed to more easily debug problems
1891 occurring only in synchronous mode.
1893 set mi-async (on|off)
1895 Control whether MI asynchronous mode is preferred. This supersedes
1896 "set target-async" of previous GDB versions.
1898 * "set target-async" is deprecated as a CLI option and is now an alias
1899 for "set mi-async" (only puts MI into async mode).
1901 * Background execution commands (e.g., "c&", "s&", etc.) are now
1902 possible ``out of the box'' if the target supports them. Previously
1903 the user would need to explicitly enable the possibility with the
1904 "set target-async on" command.
1906 * New features in the GDB remote stub, GDBserver
1908 ** New option --debug-format=option1[,option2,...] allows one to add
1909 additional text to each output. At present only timestamps
1910 are supported: --debug-format=timestamps.
1911 Timestamps can also be turned on with the
1912 "monitor set debug-format timestamps" command from GDB.
1914 * The 'record instruction-history' command now starts counting instructions
1915 at one. This also affects the instruction ranges reported by the
1916 'record function-call-history' command when given the /i modifier.
1918 * The command 'record function-call-history' supports a new modifier '/c' to
1919 indent the function names based on their call stack depth.
1920 The fields for the '/i' and '/l' modifier have been reordered.
1921 The source line range is now prefixed with 'at'.
1922 The instruction range is now prefixed with 'inst'.
1923 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1924 "record instruction-history" and "list" commands.
1926 * The ranges given as arguments to the 'record function-call-history' and
1927 'record instruction-history' commands are now inclusive.
1929 * The btrace record target now supports the 'record goto' command.
1930 For locations inside the execution trace, the back trace is computed
1931 based on the information stored in the execution trace.
1933 * The btrace record target supports limited reverse execution and replay.
1934 The target does not record data and therefore does not allow reading
1935 memory or registers.
1937 * The "catch syscall" command now works on s390*-linux* targets.
1939 * The "compare-sections" command is no longer specific to target
1940 remote. It now works with all targets.
1942 * All native targets are now consistently called "native".
1943 Consequently, the "target child", "target GNU", "target djgpp",
1944 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1945 commands have been replaced with "target native". The QNX/NTO port
1946 leaves the "procfs" target in place and adds a "native" target for
1947 consistency with other ports. The impact on users should be minimal
1948 as these commands previously either throwed an error, or were
1949 no-ops. The target's name is visible in the output of the following
1950 commands: "help target", "info target", "info files", "maint print
1953 * The "target native" command now connects to the native target. This
1954 can be used to launch native programs even when "set
1955 auto-connect-native-target" is set to off.
1957 * GDB now supports access to Intel MPX registers on GNU/Linux.
1959 * Support for Intel AVX-512 registers on GNU/Linux.
1960 Support displaying and modifying Intel AVX-512 registers
1961 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1963 * New remote packets
1965 qXfer:btrace:read's annex
1966 The qXfer:btrace:read packet supports a new annex 'delta' to read
1967 branch trace incrementally.
1971 ** Valid Python operations on gdb.Value objects representing
1972 structs/classes invoke the corresponding overloaded operators if
1974 ** New `Xmethods' feature in the Python API. Xmethods are
1975 additional methods or replacements for existing methods of a C++
1976 class. This feature is useful for those cases where a method
1977 defined in C++ source code could be inlined or optimized out by
1978 the compiler, making it unavailable to GDB.
1981 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1983 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1984 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1985 its alias "share", instead.
1987 * The commands "set remotebaud" and "show remotebaud" are no longer
1988 supported. Use "set serial baud" and "show serial baud" (respectively)
1993 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1994 target-async". The latter is left as a deprecated alias of the
1995 former for backward compatibility. If the target supports it,
1996 CLI background execution commands are now always possible by
1997 default, independently of whether the frontend stated a
1998 preference for asynchronous execution with "-gdb-set mi-async".
1999 Previously "-gdb-set target-async off" affected both MI execution
2000 commands and CLI execution commands.
2002 *** Changes in GDB 7.7
2004 * Improved support for process record-replay and reverse debugging on
2005 arm*-linux* targets. Support for thumb32 and syscall instruction
2006 recording has been added.
2008 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2010 * GDB now supports Fission DWP file format version 2.
2011 http://gcc.gnu.org/wiki/DebugFission
2013 * New convenience function "$_isvoid", to check whether an expression
2014 is void. A void expression is an expression where the type of the
2015 result is "void". For example, some convenience variables may be
2016 "void" when evaluated (e.g., "$_exitcode" before the execution of
2017 the program being debugged; or an undefined convenience variable).
2018 Another example, when calling a function whose return type is
2021 * The "maintenance print objfiles" command now takes an optional regexp.
2023 * The "catch syscall" command now works on arm*-linux* targets.
2025 * GDB now consistently shows "<not saved>" when printing values of
2026 registers the debug info indicates have not been saved in the frame
2027 and there's nowhere to retrieve them from
2028 (callee-saved/call-clobbered registers):
2033 (gdb) info registers rax
2036 Before, the former would print "<optimized out>", and the latter
2037 "*value not available*".
2039 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2044 ** Frame filters and frame decorators have been added.
2045 ** Temporary breakpoints are now supported.
2046 ** Line tables representation has been added.
2047 ** New attribute 'parent_type' for gdb.Field objects.
2048 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2049 ** New attribute 'name' for gdb.Type objects.
2053 Nios II ELF nios2*-*-elf
2054 Nios II GNU/Linux nios2*-*-linux
2055 Texas Instruments MSP430 msp430*-*-elf
2057 * Removed native configurations
2059 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2060 been removed. ELF variants of these configurations are kept supported.
2062 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2063 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2064 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2065 i[34567]86-*-openbsd3.[0-3]
2066 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2067 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2068 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2072 Like "catch throw", but catches a re-thrown exception.
2073 maint check-psymtabs
2074 Renamed from old "maint check-symtabs".
2076 Perform consistency checks on symtabs.
2077 maint expand-symtabs
2078 Expand symtabs matching an optional regexp.
2081 Display the details of GDB configure-time options.
2083 maint set|show per-command
2084 maint set|show per-command space
2085 maint set|show per-command time
2086 maint set|show per-command symtab
2087 Enable display of per-command gdb resource usage.
2089 remove-symbol-file FILENAME
2090 remove-symbol-file -a ADDRESS
2091 Remove a symbol file added via add-symbol-file. The file to remove
2092 can be identified by its filename or by an address that lies within
2093 the boundaries of this symbol file in memory.
2096 info exceptions REGEXP
2097 Display the list of Ada exceptions defined in the program being
2098 debugged. If provided, only the exceptions whose names match REGEXP
2103 set debug symfile off|on
2105 Control display of debugging info regarding reading symbol files and
2106 symbol tables within those files
2108 set print raw frame-arguments
2109 show print raw frame-arguments
2110 Set/show whether to print frame arguments in raw mode,
2111 disregarding any defined pretty-printers.
2113 set remote trace-status-packet
2114 show remote trace-status-packet
2115 Set/show the use of remote protocol qTStatus packet.
2119 Control display of debugging messages related to Nios II targets.
2123 Control whether target-assisted range stepping is enabled.
2125 set startup-with-shell
2126 show startup-with-shell
2127 Specifies whether Unix child processes are started via a shell or
2132 Use the target memory cache for accesses to the code segment. This
2133 improves performance of remote debugging (particularly disassembly).
2135 * You can now use a literal value 'unlimited' for options that
2136 interpret 0 or -1 as meaning "unlimited". E.g., "set
2137 trace-buffer-size unlimited" is now an alias for "set
2138 trace-buffer-size -1" and "set height unlimited" is now an alias for
2141 * The "set debug symtab-create" debugging option of GDB has been changed to
2142 accept a verbosity level. 0 means "off", 1 provides basic debugging
2143 output, and values of 2 or greater provides more verbose output.
2145 * New command-line options
2147 Display the details of GDB configure-time options.
2149 * The command 'tsave' can now support new option '-ctf' to save trace
2150 buffer in Common Trace Format.
2152 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2155 * GDB now implements the the C++ 'typeid' operator.
2157 * The new convenience variable $_exception holds the exception being
2158 thrown or caught at an exception-related catchpoint.
2160 * The exception-related catchpoints, like "catch throw", now accept a
2161 regular expression which can be used to filter exceptions by type.
2163 * The new convenience variable $_exitsignal is automatically set to
2164 the terminating signal number when the program being debugged dies
2165 due to an uncaught signal.
2169 ** All MI commands now accept an optional "--language" option.
2170 Support for this feature can be verified by using the "-list-features"
2171 command, which should contain "language-option".
2173 ** The new command -info-gdb-mi-command allows the user to determine
2174 whether a GDB/MI command is supported or not.
2176 ** The "^error" result record returned when trying to execute an undefined
2177 GDB/MI command now provides a variable named "code" whose content is the
2178 "undefined-command" error code. Support for this feature can be verified
2179 by using the "-list-features" command, which should contain
2180 "undefined-command-error-code".
2182 ** The -trace-save MI command can optionally save trace buffer in Common
2185 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2187 ** The command -data-list-register-values now accepts an optional
2188 "--skip-unavailable" option. When used, only the available registers
2191 ** The new command -trace-frame-collected dumps collected variables,
2192 computed expressions, tvars, memory and registers in a traceframe.
2194 ** The commands -stack-list-locals, -stack-list-arguments and
2195 -stack-list-variables now accept an option "--skip-unavailable".
2196 When used, only the available locals or arguments are displayed.
2198 ** The -exec-run command now accepts an optional "--start" option.
2199 When used, the command follows the same semantics as the "start"
2200 command, stopping the program's execution at the start of its
2201 main subprogram. Support for this feature can be verified using
2202 the "-list-features" command, which should contain
2203 "exec-run-start-option".
2205 ** The new commands -catch-assert and -catch-exceptions insert
2206 catchpoints stopping the program when Ada exceptions are raised.
2208 ** The new command -info-ada-exceptions provides the equivalent of
2209 the new "info exceptions" command.
2211 * New system-wide configuration scripts
2212 A GDB installation now provides scripts suitable for use as system-wide
2213 configuration scripts for the following systems:
2217 * GDB now supports target-assigned range stepping with remote targets.
2218 This improves the performance of stepping source lines by reducing
2219 the number of control packets from/to GDB. See "New remote packets"
2222 * GDB now understands the element 'tvar' in the XML traceframe info.
2223 It has the id of the collected trace state variables.
2225 * On S/390 targets that provide the transactional-execution feature,
2226 the program interruption transaction diagnostic block (TDB) is now
2227 represented as a number of additional "registers" in GDB.
2229 * New remote packets
2233 The vCont packet supports a new 'r' action, that tells the remote
2234 stub to step through an address range itself, without GDB
2235 involvemement at each single-step.
2237 qXfer:libraries-svr4:read's annex
2238 The previously unused annex of the qXfer:libraries-svr4:read packet
2239 is now used to support passing an argument list. The remote stub
2240 reports support for this argument list to GDB's qSupported query.
2241 The defined arguments are "start" and "prev", used to reduce work
2242 necessary for library list updating, resulting in significant
2245 * New features in the GDB remote stub, GDBserver
2247 ** GDBserver now supports target-assisted range stepping. Currently
2248 enabled on x86/x86_64 GNU/Linux targets.
2250 ** GDBserver now adds element 'tvar' in the XML in the reply to
2251 'qXfer:traceframe-info:read'. It has the id of the collected
2252 trace state variables.
2254 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2257 * New 'z' formatter for printing and examining memory, this displays the
2258 value as hexadecimal zero padded on the left to the size of the type.
2260 * GDB can now use Windows x64 unwinding data.
2262 * The "set remotebaud" command has been replaced by "set serial baud".
2263 Similarly, "show remotebaud" has been replaced by "show serial baud".
2264 The "set remotebaud" and "show remotebaud" commands are still available
2265 to provide backward compatibility with older versions of GDB.
2267 *** Changes in GDB 7.6
2269 * Target record has been renamed to record-full.
2270 Record/replay is now enabled with the "record full" command.
2271 This also affects settings that are associated with full record/replay
2272 that have been moved from "set/show record" to "set/show record full":
2274 set|show record full insn-number-max
2275 set|show record full stop-at-limit
2276 set|show record full memory-query
2278 * A new record target "record-btrace" has been added. The new target
2279 uses hardware support to record the control-flow of a process. It
2280 does not support replaying the execution, but it implements the
2281 below new commands for investigating the recorded execution log.
2282 This new recording method can be enabled using:
2286 The "record-btrace" target is only available on Intel Atom processors
2287 and requires a Linux kernel 2.6.32 or later.
2289 * Two new commands have been added for record/replay to give information
2290 about the recorded execution without having to replay the execution.
2291 The commands are only supported by "record btrace".
2293 record instruction-history prints the execution history at
2294 instruction granularity
2296 record function-call-history prints the execution history at
2297 function granularity
2299 * New native configurations
2301 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2302 FreeBSD/powerpc powerpc*-*-freebsd
2303 x86_64/Cygwin x86_64-*-cygwin*
2304 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2308 ARM AArch64 aarch64*-*-elf
2309 ARM AArch64 GNU/Linux aarch64*-*-linux
2310 Lynx 178 PowerPC powerpc-*-lynx*178
2311 x86_64/Cygwin x86_64-*-cygwin*
2312 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2314 * If the configured location of system.gdbinit file (as given by the
2315 --with-system-gdbinit option at configure time) is in the
2316 data-directory (as specified by --with-gdb-datadir at configure
2317 time) or in one of its subdirectories, then GDB will look for the
2318 system-wide init file in the directory specified by the
2319 --data-directory command-line option.
2321 * New command line options:
2323 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2324 other initialization files, unlike -nx which disables all of them.
2326 * Removed command line options
2328 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2331 * The 'ptype' and 'whatis' commands now accept an argument to control
2334 * 'info proc' now works on some core files.
2338 ** Vectors can be created with gdb.Type.vector.
2340 ** Python's atexit.register now works in GDB.
2342 ** Types can be pretty-printed via a Python API.
2344 ** Python 3 is now supported (in addition to Python 2.4 or later)
2346 ** New class gdb.Architecture exposes GDB's internal representation
2347 of architecture in the Python API.
2349 ** New method Frame.architecture returns the gdb.Architecture object
2350 corresponding to the frame's architecture.
2352 * New Python-based convenience functions:
2354 ** $_memeq(buf1, buf2, length)
2355 ** $_streq(str1, str2)
2357 ** $_regex(str, regex)
2359 * The 'cd' command now defaults to using '~' (the home directory) if not
2362 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2363 default for GCC since November 2000.
2365 * The command 'forward-search' can now be abbreviated as 'fo'.
2367 * The command 'info tracepoints' can now display 'installed on target'
2368 or 'not installed on target' for each non-pending location of tracepoint.
2370 * New configure options
2372 --enable-libmcheck/--disable-libmcheck
2373 By default, development versions are built with -lmcheck on hosts
2374 that support it, in order to help track memory corruption issues.
2375 Release versions, on the other hand, are built without -lmcheck
2376 by default. The --enable-libmcheck/--disable-libmcheck configure
2377 options allow the user to override that default.
2378 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2379 This configure option allows the user to build GDB with
2380 libbabeltrace using which GDB can read Common Trace Format data.
2382 * New commands (for set/show, see "New options" below)
2385 Catch signals. This is similar to "handle", but allows commands and
2386 conditions to be attached.
2389 List the BFDs known to GDB.
2391 python-interactive [command]
2393 Start a Python interactive prompt, or evaluate the optional command
2394 and print the result of expressions.
2397 "py" is a new alias for "python".
2399 enable type-printer [name]...
2400 disable type-printer [name]...
2401 Enable or disable type printers.
2405 ** For the Renesas Super-H architecture, the "regs" command has been removed
2406 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2411 set print type methods (on|off)
2412 show print type methods
2413 Control whether method declarations are displayed by "ptype".
2414 The default is to show them.
2416 set print type typedefs (on|off)
2417 show print type typedefs
2418 Control whether typedef definitions are displayed by "ptype".
2419 The default is to show them.
2421 set filename-display basename|relative|absolute
2422 show filename-display
2423 Control the way in which filenames is displayed.
2424 The default is "relative", which preserves previous behavior.
2426 set trace-buffer-size
2427 show trace-buffer-size
2428 Request target to change the size of trace buffer.
2430 set remote trace-buffer-size-packet auto|on|off
2431 show remote trace-buffer-size-packet
2432 Control the use of the remote protocol `QTBuffer:size' packet.
2436 Control display of debugging messages related to ARM AArch64.
2439 set debug coff-pe-read
2440 show debug coff-pe-read
2441 Control display of debugging messages related to reading of COFF/PE
2446 Control display of debugging messages related to Mach-O symbols
2449 set debug notification
2450 show debug notification
2451 Control display of debugging info for async remote notification.
2455 ** Command parameter changes are now notified using new async record
2456 "=cmd-param-changed".
2457 ** Trace frame changes caused by command "tfind" are now notified using
2458 new async record "=traceframe-changed".
2459 ** The creation, deletion and modification of trace state variables
2460 are now notified using new async records "=tsv-created",
2461 "=tsv-deleted" and "=tsv-modified".
2462 ** The start and stop of process record are now notified using new
2463 async record "=record-started" and "=record-stopped".
2464 ** Memory changes are now notified using new async record
2466 ** The data-disassemble command response will include a "fullname" field
2467 containing the absolute file name when source has been requested.
2468 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2469 command, to allow pattern filling of memory areas.
2470 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2471 library load/unload events.
2472 ** The response to breakpoint commands and breakpoint async records
2473 includes an "installed" field containing a boolean state about each
2474 non-pending tracepoint location is whether installed on target or not.
2475 ** Output of the "-trace-status" command includes a "trace-file" field
2476 containing the name of the trace file being examined. This field is
2477 optional, and only present when examining a trace file.
2478 ** The "fullname" field is now always present along with the "file" field,
2479 even if the file cannot be found by GDB.
2481 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2482 You must have the LZMA library available when configuring GDB for this
2483 feature to be enabled. For more information, see:
2484 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2486 * New remote packets
2489 Set the size of trace buffer. The remote stub reports support for this
2490 packet to gdb's qSupported query.
2493 Enable Branch Trace Store (BTS)-based branch tracing for the current
2494 thread. The remote stub reports support for this packet to gdb's
2498 Disable branch tracing for the current thread. The remote stub reports
2499 support for this packet to gdb's qSupported query.
2502 Read the traced branches for the current thread. The remote stub
2503 reports support for this packet to gdb's qSupported query.
2505 *** Changes in GDB 7.5
2507 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2508 for more x32 ABI info.
2510 * GDB now supports access to MIPS DSP registers on Linux targets.
2512 * GDB now supports debugging microMIPS binaries.
2514 * The "info os" command on GNU/Linux can now display information on
2515 several new classes of objects managed by the operating system:
2516 "info os procgroups" lists process groups
2517 "info os files" lists file descriptors
2518 "info os sockets" lists internet-domain sockets
2519 "info os shm" lists shared-memory regions
2520 "info os semaphores" lists semaphores
2521 "info os msg" lists message queues
2522 "info os modules" lists loaded kernel modules
2524 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2525 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2526 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2527 options and inspect the probe arguments using the new $_probe_arg family
2528 of convenience variables. You can obtain more information about SystemTap
2529 in <http://sourceware.org/systemtap/>.
2531 * GDB now supports reversible debugging on ARM, it allows you to
2532 debug basic ARM and THUMB instructions, and provides
2533 record/replay support.
2535 * The option "symbol-reloading" has been deleted as it is no longer used.
2539 ** GDB commands implemented in Python can now be put in command class
2542 ** The "maint set python print-stack on|off" is now deleted.
2544 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2545 apply "flag enum"-style pretty-printing to any enum.
2547 ** gdb.lookup_symbol can now work when there is no current frame.
2549 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2550 the source at which the symbol was defined.
2552 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2553 method 'value'. The former indicates whether the symbol needs a
2554 frame in order to compute its value, and the latter computes the
2557 ** A new method 'referenced_value' on gdb.Value objects which can
2558 dereference pointer as well as C++ reference values.
2560 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2561 which return the global and static blocks (as gdb.Block objects),
2562 of the underlying symbol table, respectively.
2564 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2565 object associated with a PC value.
2567 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2568 of the address range occupied by code for the current source line.
2570 * Go language support.
2571 GDB now supports debugging programs written in the Go programming
2574 * GDBserver now supports stdio connections.
2575 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2577 * The binary "gdbtui" can no longer be built or installed.
2578 Use "gdb -tui" instead.
2580 * GDB will now print "flag" enums specially. A flag enum is one where
2581 all the enumerator values have no bits in common when pairwise
2582 "and"ed. When printing a value whose type is a flag enum, GDB will
2583 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2584 (gdb) print (enum E) 3
2587 * The filename part of a linespec will now match trailing components
2588 of a source file name. For example, "break gcc/expr.c:1000" will
2589 now set a breakpoint in build/gcc/expr.c, but not
2590 build/libcpp/expr.c.
2592 * The "info proc" and "generate-core-file" commands will now also
2593 work on remote targets connected to GDBserver on Linux.
2595 * The command "info catch" has been removed. It has been disabled
2596 since December 2007.
2598 * The "catch exception" and "catch assert" commands now accept
2599 a condition at the end of the command, much like the "break"
2600 command does. For instance:
2602 (gdb) catch exception Constraint_Error if Barrier = True
2604 Previously, it was possible to add a condition to such catchpoints,
2605 but it had to be done as a second step, after the catchpoint had been
2606 created, using the "condition" command.
2608 * The "info static-tracepoint-marker" command will now also work on
2609 native Linux targets with in-process agent.
2611 * GDB can now set breakpoints on inlined functions.
2613 * The .gdb_index section has been updated to include symbols for
2614 inlined functions. GDB will ignore older .gdb_index sections by
2615 default, which could cause symbol files to be loaded more slowly
2616 until their .gdb_index sections can be recreated. The new command
2617 "set use-deprecated-index-sections on" will cause GDB to use any older
2618 .gdb_index sections it finds. This will restore performance, but the
2619 ability to set breakpoints on inlined functions will be lost in symbol
2620 files with older .gdb_index sections.
2622 The .gdb_index section has also been updated to record more information
2623 about each symbol. This speeds up the "info variables", "info functions"
2624 and "info types" commands when used with programs having the .gdb_index
2625 section, as well as speeding up debugging with shared libraries using
2626 the .gdb_index section.
2628 * Ada support for GDB/MI Variable Objects has been added.
2630 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2635 ** New command -info-os is the MI equivalent of "info os".
2637 ** Output logs ("set logging" and related) now include MI output.
2641 ** "set use-deprecated-index-sections on|off"
2642 "show use-deprecated-index-sections on|off"
2643 Controls the use of deprecated .gdb_index sections.
2645 ** "catch load" and "catch unload" can be used to stop when a shared
2646 library is loaded or unloaded, respectively.
2648 ** "enable count" can be used to auto-disable a breakpoint after
2651 ** "info vtbl" can be used to show the virtual method tables for
2652 C++ and Java objects.
2654 ** "explore" and its sub commands "explore value" and "explore type"
2655 can be used to recursively explore values and types of
2656 expressions. These commands are available only if GDB is
2657 configured with '--with-python'.
2659 ** "info auto-load" shows status of all kinds of auto-loaded files,
2660 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2661 sequences of commands files, "info auto-load python-scripts"
2662 shows status of auto-loading Python script files,
2663 "info auto-load local-gdbinit" shows status of loading init file
2664 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2665 status of inferior specific thread debugging shared library loading.
2667 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2668 and "show auto-load-scripts" commands have been deprecated, use their
2669 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2670 and "show auto-load python-scripts" counterparts instead.
2672 ** "dprintf location,format,args..." creates a dynamic printf, which
2673 is basically a breakpoint that does a printf and immediately
2674 resumes your program's execution, so it is like a printf that you
2675 can insert dynamically at runtime instead of at compiletime.
2677 ** "set print symbol"
2679 Controls whether GDB attempts to display the symbol, if any,
2680 corresponding to addresses it prints. This defaults to "on", but
2681 you can set it to "off" to restore GDB's previous behavior.
2683 * Deprecated commands
2685 ** For the Renesas Super-H architecture, the "regs" command has been
2686 deprecated, and "info all-registers" should be used instead.
2690 Renesas RL78 rl78-*-elf
2691 HP OpenVMS ia64 ia64-hp-openvms*
2693 * GDBserver supports evaluation of breakpoint conditions. When
2694 support is advertised by GDBserver, GDB may be told to send the
2695 breakpoint conditions in bytecode form to GDBserver. GDBserver
2696 will only report the breakpoint trigger to GDB when its condition
2701 set mips compression
2702 show mips compression
2703 Select the compressed ISA encoding used in functions that have no symbol
2704 information available. The encoding can be set to either of:
2707 and is updated automatically from ELF file flags if available.
2709 set breakpoint condition-evaluation
2710 show breakpoint condition-evaluation
2711 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2712 GDBserver ("target"). Default option "auto" chooses the most efficient
2714 This option can improve debugger efficiency depending on the speed of the
2718 Disable auto-loading globally.
2721 Show auto-loading setting of all kinds of auto-loaded files.
2723 set auto-load gdb-scripts on|off
2724 show auto-load gdb-scripts
2725 Control auto-loading of GDB canned sequences of commands files.
2727 set auto-load python-scripts on|off
2728 show auto-load python-scripts
2729 Control auto-loading of Python script files.
2731 set auto-load local-gdbinit on|off
2732 show auto-load local-gdbinit
2733 Control loading of init file (.gdbinit) from current directory.
2735 set auto-load libthread-db on|off
2736 show auto-load libthread-db
2737 Control auto-loading of inferior specific thread debugging shared library.
2739 set auto-load scripts-directory <dir1>[:<dir2>...]
2740 show auto-load scripts-directory
2741 Set a list of directories from which to load auto-loaded scripts.
2742 Automatically loaded Python scripts and GDB scripts are located in one
2743 of the directories listed by this option.
2744 The delimiter (':' above) may differ according to the host platform.
2746 set auto-load safe-path <dir1>[:<dir2>...]
2747 show auto-load safe-path
2748 Set a list of directories from which it is safe to auto-load files.
2749 The delimiter (':' above) may differ according to the host platform.
2751 set debug auto-load on|off
2752 show debug auto-load
2753 Control display of debugging info for auto-loading the files above.
2755 set dprintf-style gdb|call|agent
2757 Control the way in which a dynamic printf is performed; "gdb"
2758 requests a GDB printf command, while "call" causes dprintf to call a
2759 function in the inferior. "agent" requests that the target agent
2760 (such as GDBserver) do the printing.
2762 set dprintf-function <expr>
2763 show dprintf-function
2764 set dprintf-channel <expr>
2765 show dprintf-channel
2766 Set the function and optional first argument to the call when using
2767 the "call" style of dynamic printf.
2769 set disconnected-dprintf on|off
2770 show disconnected-dprintf
2771 Control whether agent-style dynamic printfs continue to be in effect
2772 after GDB disconnects.
2774 * New configure options
2776 --with-auto-load-dir
2777 Configure default value for the 'set auto-load scripts-directory'
2778 setting above. It defaults to '$debugdir:$datadir/auto-load',
2779 $debugdir representing global debugging info directories (available
2780 via 'show debug-file-directory') and $datadir representing GDB's data
2781 directory (available via 'show data-directory').
2783 --with-auto-load-safe-path
2784 Configure default value for the 'set auto-load safe-path' setting
2785 above. It defaults to the --with-auto-load-dir setting.
2787 --without-auto-load-safe-path
2788 Set 'set auto-load safe-path' to '/', effectively disabling this
2791 * New remote packets
2793 z0/z1 conditional breakpoints extension
2795 The z0/z1 breakpoint insertion packets have been extended to carry
2796 a list of conditional expressions over to the remote stub depending on the
2797 condition evaluation mode. The use of this extension can be controlled
2798 via the "set remote conditional-breakpoints-packet" command.
2802 Specify the signals which the remote stub may pass to the debugged
2803 program without GDB involvement.
2805 * New command line options
2807 --init-command=FILE, -ix Like --command, -x but execute it
2808 before loading inferior.
2809 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2810 execute it before loading inferior.
2812 *** Changes in GDB 7.4
2814 * GDB now handles ambiguous linespecs more consistently; the existing
2815 FILE:LINE support has been expanded to other types of linespecs. A
2816 breakpoint will now be set on all matching locations in all
2817 inferiors, and locations will be added or removed according to
2820 * GDB now allows you to skip uninteresting functions and files when
2821 stepping with the "skip function" and "skip file" commands.
2823 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2824 and "show remote hardware-watchpoint-length-limit". These allows to
2825 set or show the maximum length limit (in bytes) of a remote
2826 target hardware watchpoint.
2828 This allows e.g. to use "unlimited" hardware watchpoints with the
2829 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2830 watchpoints are slower than real hardware watchpoints but are
2831 significantly faster than gdb software watchpoints.
2835 ** The register_pretty_printer function in module gdb.printing now takes
2836 an optional `replace' argument. If True, the new printer replaces any
2839 ** The "maint set python print-stack on|off" command has been
2840 deprecated and will be deleted in GDB 7.5.
2841 A new command: "set python print-stack none|full|message" has
2842 replaced it. Additionally, the default for "print-stack" is
2843 now "message", which just prints the error message without
2846 ** A prompt substitution hook (prompt_hook) is now available to the
2849 ** A new Python module, gdb.prompt has been added to the GDB Python
2850 modules library. This module provides functionality for
2851 escape sequences in prompts (used by set/show
2852 extended-prompt). These escape sequences are replaced by their
2853 corresponding value.
2855 ** Python commands and convenience-functions located in
2856 'data-directory'/python/gdb/command and
2857 'data-directory'/python/gdb/function are now automatically loaded
2860 ** Blocks now provide four new attributes. global_block and
2861 static_block will return the global and static blocks
2862 respectively. is_static and is_global are boolean attributes
2863 that indicate if the block is one of those two types.
2865 ** Symbols now provide the "type" attribute, the type of the symbol.
2867 ** The "gdb.breakpoint" function has been deprecated in favor of
2870 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2871 of a function. This class is based on the "finish" command
2872 available in the CLI.
2874 ** Type objects for struct and union types now allow access to
2875 the fields using standard Python dictionary (mapping) methods.
2876 For example, "some_type['myfield']" now works, as does
2877 "some_type.items()".
2879 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2882 ** A new function, "deep_items" has been added to the gdb.types
2883 module in the GDB Python modules library. This function returns
2884 an iterator over the fields of a struct or union type. Unlike
2885 the standard Python "iteritems" method, it will recursively traverse
2886 any anonymous fields.
2890 ** "*stopped" events can report several new "reason"s, such as
2893 ** Breakpoint changes are now notified using new async records, like
2894 "=breakpoint-modified".
2896 ** New command -ada-task-info.
2898 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2899 $sdir specifies the default system locations of shared libraries.
2900 $pdir specifies the directory where the libpthread used by the application
2903 GDB no longer looks in $sdir and $pdir after it has searched the directories
2904 mentioned in libthread-db-search-path. If you want to search those
2905 directories, they must be specified in libthread-db-search-path.
2906 The default value of libthread-db-search-path on GNU/Linux and Solaris
2907 systems is now "$sdir:$pdir".
2909 $pdir is not supported by gdbserver, it is currently ignored.
2910 $sdir is supported by gdbserver.
2912 * New configure option --with-iconv-bin.
2913 When using the internationalization support like the one in the GNU C
2914 library, GDB will invoke the "iconv" program to get a list of supported
2915 character sets. If this program lives in a non-standard location, one can
2916 use this option to specify where to find it.
2918 * When natively debugging programs on PowerPC BookE processors running
2919 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2920 watchpoints, which specify a mask in addition to an address to watch.
2921 The mask specifies that some bits of an address (the bits which are
2922 reset in the mask) should be ignored when matching the address accessed
2923 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2924 section in the user manual for more details.
2926 * The new option --once causes GDBserver to stop listening for connections once
2927 the first connection is made. The listening port used by GDBserver will
2928 become available after that.
2930 * New commands "info macros" and "alias" have been added.
2932 * New function parameters suffix @entry specifies value of function parameter
2933 at the time the function got called. Entry values are available only since
2939 "!" is now an alias of the "shell" command.
2940 Note that no space is needed between "!" and SHELL COMMAND.
2944 watch EXPRESSION mask MASK_VALUE
2945 The watch command now supports the mask argument which allows creation
2946 of masked watchpoints, if the current architecture supports this feature.
2948 info auto-load-scripts [REGEXP]
2949 This command was formerly named "maintenance print section-scripts".
2950 It is now generally useful and is no longer a maintenance-only command.
2952 info macro [-all] [--] MACRO
2953 The info macro command has new options `-all' and `--'. The first for
2954 printing all definitions of a macro. The second for explicitly specifying
2955 the end of arguments and the beginning of the macro name in case the macro
2956 name starts with a hyphen.
2958 collect[/s] EXPRESSIONS
2959 The tracepoint collect command now takes an optional modifier "/s"
2960 that directs it to dereference pointer-to-character types and
2961 collect the bytes of memory up to a zero byte. The behavior is
2962 similar to what you see when you use the regular print command on a
2963 string. An optional integer following the "/s" sets a bound on the
2964 number of bytes that will be collected.
2967 The trace start command now interprets any supplied arguments as a
2968 note to be recorded with the trace run, with an effect similar to
2969 setting the variable trace-notes.
2972 The trace stop command now interprets any arguments as a note to be
2973 mentioned along with the tstatus report that the trace was stopped
2974 with a command. The effect is similar to setting the variable
2977 * Tracepoints can now be enabled and disabled at any time after a trace
2978 experiment has been started using the standard "enable" and "disable"
2979 commands. It is now possible to start a trace experiment with no enabled
2980 tracepoints; GDB will display a warning, but will allow the experiment to
2981 begin, assuming that tracepoints will be enabled as needed while the trace
2984 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2985 locations with 4-byte instructions, when they were previously
2986 limited to locations with instructions of 5 bytes or longer.
2990 set debug dwarf2-read
2991 show debug dwarf2-read
2992 Turns on or off display of debugging messages related to reading
2993 DWARF debug info. The default is off.
2995 set debug symtab-create
2996 show debug symtab-create
2997 Turns on or off display of debugging messages related to symbol table
2998 creation. The default is off.
3001 show extended-prompt
3002 Set the GDB prompt, and allow escape sequences to be inserted to
3003 display miscellaneous information (see 'help set extended-prompt'
3004 for the list of sequences). This prompt (and any information
3005 accessed through the escape sequences) is updated every time the
3006 prompt is displayed.
3008 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3009 show print entry-values
3010 Set printing of frame argument values at function entry. In some cases
3011 GDB can determine the value of function argument which was passed by the
3012 function caller, even if the value was modified inside the called function.
3014 set debug entry-values
3015 show debug entry-values
3016 Control display of debugging info for determining frame argument values at
3017 function entry and virtual tail call frames.
3019 set basenames-may-differ
3020 show basenames-may-differ
3021 Set whether a source file may have multiple base names.
3022 (A "base name" is the name of a file with the directory part removed.
3023 Example: The base name of "/home/user/hello.c" is "hello.c".)
3024 If set, GDB will canonicalize file names (e.g., expand symlinks)
3025 before comparing them. Canonicalization is an expensive operation,
3026 but it allows the same file be known by more than one base name.
3027 If not set (the default), all source files are assumed to have just
3028 one base name, and gdb will do file name comparisons more efficiently.
3034 Set a user name and notes for the current and any future trace runs.
3035 This is useful for long-running and/or disconnected traces, to
3036 inform others (or yourself) as to who is running the trace, supply
3037 contact information, or otherwise explain what is going on.
3039 set trace-stop-notes
3040 show trace-stop-notes
3041 Set a note attached to the trace run, that is displayed when the
3042 trace has been stopped by a tstop command. This is useful for
3043 instance as an explanation, if you are stopping a trace run that was
3044 started by someone else.
3046 * New remote packets
3050 Dynamically enable a tracepoint in a started trace experiment.
3054 Dynamically disable a tracepoint in a started trace experiment.
3058 Set the user and notes of the trace run.
3062 Query the current status of a tracepoint.
3066 Query the minimum length of instruction at which a fast tracepoint may
3069 * Dcache size (number of lines) and line-size are now runtime-configurable
3070 via "set dcache line" and "set dcache line-size" commands.
3074 Texas Instruments TMS320C6x tic6x-*-*
3078 Renesas RL78 rl78-*-elf
3080 *** Changes in GDB 7.3.1
3082 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3084 *** Changes in GDB 7.3
3086 * GDB has a new command: "thread find [REGEXP]".
3087 It finds the thread id whose name, target id, or thread extra info
3088 matches the given regular expression.
3090 * The "catch syscall" command now works on mips*-linux* targets.
3092 * The -data-disassemble MI command now supports modes 2 and 3 for
3093 dumping the instruction opcodes.
3095 * New command line options
3097 -data-directory DIR Specify DIR as the "data-directory".
3098 This is mostly for testing purposes.
3100 * The "maint set python auto-load on|off" command has been renamed to
3101 "set auto-load-scripts on|off".
3103 * GDB has a new command: "set directories".
3104 It is like the "dir" command except that it replaces the
3105 source path list instead of augmenting it.
3107 * GDB now understands thread names.
3109 On GNU/Linux, "info threads" will display the thread name as set by
3110 prctl or pthread_setname_np.
3112 There is also a new command, "thread name", which can be used to
3113 assign a name internally for GDB to display.
3116 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3117 has been integrated into GDB.
3121 ** The function gdb.Write now accepts an optional keyword 'stream'.
3122 This keyword, when provided, will direct the output to either
3123 stdout, stderr, or GDB's logging output.
3125 ** Parameters can now be be sub-classed in Python, and in particular
3126 you may implement the get_set_doc and get_show_doc functions.
3127 This improves how Parameter set/show documentation is processed
3128 and allows for more dynamic content.
3130 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3131 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3132 have an is_valid method.
3134 ** Breakpoints can now be sub-classed in Python, and in particular
3135 you may implement a 'stop' function that is executed each time
3136 the inferior reaches that breakpoint.
3138 ** New function gdb.lookup_global_symbol looks up a global symbol.
3140 ** GDB values in Python are now callable if the value represents a
3141 function. For example, if 'some_value' represents a function that
3142 takes two integer parameters and returns a value, you can call
3143 that function like so:
3145 result = some_value (10,20)
3147 ** Module gdb.types has been added.
3148 It contains a collection of utilities for working with gdb.Types objects:
3149 get_basic_type, has_field, make_enum_dict.
3151 ** Module gdb.printing has been added.
3152 It contains utilities for writing and registering pretty-printers.
3153 New classes: PrettyPrinter, SubPrettyPrinter,
3154 RegexpCollectionPrettyPrinter.
3155 New function: register_pretty_printer.
3157 ** New commands "info pretty-printers", "enable pretty-printer" and
3158 "disable pretty-printer" have been added.
3160 ** gdb.parameter("directories") is now available.
3162 ** New function gdb.newest_frame returns the newest frame in the
3165 ** The gdb.InferiorThread class has a new "name" attribute. This
3166 holds the thread's name.
3168 ** Python Support for Inferior events.
3169 Python scripts can add observers to be notified of events
3170 occurring in the process being debugged.
3171 The following events are currently supported:
3172 - gdb.events.cont Continue event.
3173 - gdb.events.exited Inferior exited event.
3174 - gdb.events.stop Signal received, and Breakpoint hit events.
3178 ** GDB now puts template parameters in scope when debugging in an
3179 instantiation. For example, if you have:
3181 template<int X> int func (void) { return X; }
3183 then if you step into func<5>, "print X" will show "5". This
3184 feature requires proper debuginfo support from the compiler; it
3185 was added to GCC 4.5.
3187 ** The motion commands "next", "finish", "until", and "advance" now
3188 work better when exceptions are thrown. In particular, GDB will
3189 no longer lose control of the inferior; instead, the GDB will
3190 stop the inferior at the point at which the exception is caught.
3191 This functionality requires a change in the exception handling
3192 code that was introduced in GCC 4.5.
3194 * GDB now follows GCC's rules on accessing volatile objects when
3195 reading or writing target state during expression evaluation.
3196 One notable difference to prior behavior is that "print x = 0"
3197 no longer generates a read of x; the value of the assignment is
3198 now always taken directly from the value being assigned.
3200 * GDB now has some support for using labels in the program's source in
3201 linespecs. For instance, you can use "advance label" to continue
3202 execution to a label.
3204 * GDB now has support for reading and writing a new .gdb_index
3205 section. This section holds a fast index of DWARF debugging
3206 information and can be used to greatly speed up GDB startup and
3207 operation. See the documentation for `save gdb-index' for details.
3209 * The "watch" command now accepts an optional "-location" argument.
3210 When used, this causes GDB to watch the memory referred to by the
3211 expression. Such a watchpoint is never deleted due to it going out
3214 * GDB now supports thread debugging of core dumps on GNU/Linux.
3216 GDB now activates thread debugging using the libthread_db library
3217 when debugging GNU/Linux core dumps, similarly to when debugging
3218 live processes. As a result, when debugging a core dump file, GDB
3219 is now able to display pthread_t ids of threads. For example, "info
3220 threads" shows the same output as when debugging the process when it
3221 was live. In earlier releases, you'd see something like this:
3224 * 1 LWP 6780 main () at main.c:10
3226 While now you see this:
3229 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3231 It is also now possible to inspect TLS variables when debugging core
3234 When debugging a core dump generated on a machine other than the one
3235 used to run GDB, you may need to point GDB at the correct
3236 libthread_db library with the "set libthread-db-search-path"
3237 command. See the user manual for more details on this command.
3239 * When natively debugging programs on PowerPC BookE processors running
3240 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3241 which stop execution of the inferior whenever it executes an instruction
3242 at any address within the specified range. See the "PowerPC Embedded"
3243 section in the user manual for more details.
3245 * New features in the GDB remote stub, GDBserver
3247 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3248 and i686 LynxOS (version 5.x).
3250 ** GDBserver is now supported on Blackfin Linux.
3252 * New native configurations
3254 ia64 HP-UX ia64-*-hpux*
3258 Analog Devices, Inc. Blackfin Processor bfin-*
3260 * Ada task switching is now supported on sparc-elf targets when
3261 debugging a program using the Ravenscar Profile. For more information,
3262 see the "Tasking Support when using the Ravenscar Profile" section
3263 in the GDB user manual.
3265 * Guile support was removed.
3267 * New features in the GNU simulator
3269 ** The --map-info flag lists all known core mappings.
3271 ** CFI flashes may be simulated via the "cfi" device.
3273 *** Changes in GDB 7.2
3275 * Shared library support for remote targets by default
3277 When GDB is configured for a generic, non-OS specific target, like
3278 for example, --target=arm-eabi or one of the many *-*-elf targets,
3279 GDB now queries remote stubs for loaded shared libraries using the
3280 `qXfer:libraries:read' packet. Previously, shared library support
3281 was always disabled for such configurations.
3285 ** Argument Dependent Lookup (ADL)
3287 In C++ ADL lookup directs function search to the namespaces of its
3288 arguments even if the namespace has not been imported.
3298 Here the compiler will search for `foo' in the namespace of 'b'
3299 and find A::foo. GDB now supports this. This construct is commonly
3300 used in the Standard Template Library for operators.
3302 ** Improved User Defined Operator Support
3304 In addition to member operators, GDB now supports lookup of operators
3305 defined in a namespace and imported with a `using' directive, operators
3306 defined in the global scope, operators imported implicitly from an
3307 anonymous namespace, and the ADL operators mentioned in the previous
3309 GDB now also supports proper overload resolution for all the previously
3310 mentioned flavors of operators.
3312 ** static const class members
3314 Printing of static const class members that are initialized in the
3315 class definition has been fixed.
3317 * Windows Thread Information Block access.
3319 On Windows targets, GDB now supports displaying the Windows Thread
3320 Information Block (TIB) structure. This structure is visible either
3321 by using the new command `info w32 thread-information-block' or, by
3322 dereferencing the new convenience variable named `$_tlb', a
3323 thread-specific pointer to the TIB. This feature is also supported
3324 when remote debugging using GDBserver.
3326 * Static tracepoints
3328 Static tracepoints are calls in the user program into a tracing
3329 library. One such library is a port of the LTTng kernel tracer to
3330 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3331 When debugging with GDBserver, GDB now supports combining the GDB
3332 tracepoint machinery with such libraries. For example: the user can
3333 use GDB to probe a static tracepoint marker (a call from the user
3334 program into the tracing library) with the new "strace" command (see
3335 "New commands" below). This creates a "static tracepoint" in the
3336 breakpoint list, that can be manipulated with the same feature set
3337 as fast and regular tracepoints. E.g., collect registers, local and
3338 global variables, collect trace state variables, and define
3339 tracepoint conditions. In addition, the user can collect extra
3340 static tracepoint marker specific data, by collecting the new
3341 $_sdata internal variable. When analyzing the trace buffer, you can
3342 inspect $_sdata like any other variable available to GDB. For more
3343 information, see the "Tracepoints" chapter in GDB user manual. New
3344 remote packets have been defined to support static tracepoints, see
3345 the "New remote packets" section below.
3347 * Better reconstruction of tracepoints after disconnected tracing
3349 GDB will attempt to download the original source form of tracepoint
3350 definitions when starting a trace run, and then will upload these
3351 upon reconnection to the target, resulting in a more accurate
3352 reconstruction of the tracepoints that are in use on the target.
3356 You can now exercise direct control over the ways that GDB can
3357 affect your program. For instance, you can disallow the setting of
3358 breakpoints, so that the program can run continuously (assuming
3359 non-stop mode). In addition, the "observer" variable is available
3360 to switch all of the different controls; in observer mode, GDB
3361 cannot affect the target's behavior at all, which is useful for
3362 tasks like diagnosing live systems in the field.
3364 * The new convenience variable $_thread holds the number of the
3367 * New remote packets
3371 Return the address of the Windows Thread Information Block of a given thread.
3375 In response to several of the tracepoint packets, the target may now
3376 also respond with a number of intermediate `qRelocInsn' request
3377 packets before the final result packet, to have GDB handle
3378 relocating an instruction to execute at a different address. This
3379 is particularly useful for stubs that support fast tracepoints. GDB
3380 reports support for this feature in the qSupported packet.
3384 List static tracepoint markers in the target program.
3388 List static tracepoint markers at a given address in the target
3391 qXfer:statictrace:read
3393 Read the static trace data collected (by a `collect $_sdata'
3394 tracepoint action). The remote stub reports support for this packet
3395 to gdb's qSupported query.
3399 Send the current settings of GDB's permission flags.
3403 Send part of the source (textual) form of a tracepoint definition,
3404 which includes location, conditional, and action list.
3406 * The source command now accepts a -s option to force searching for the
3407 script in the source search path even if the script name specifies
3410 * New features in the GDB remote stub, GDBserver
3412 - GDBserver now support tracepoints (including fast tracepoints, and
3413 static tracepoints). The feature is currently supported by the
3414 i386-linux and amd64-linux builds. See the "Tracepoints support
3415 in gdbserver" section in the manual for more information.
3417 GDBserver JIT compiles the tracepoint's conditional agent
3418 expression bytecode into native code whenever possible for low
3419 overhead dynamic tracepoints conditionals. For such tracepoints,
3420 an expression that examines program state is evaluated when the
3421 tracepoint is reached, in order to determine whether to capture
3422 trace data. If the condition is simple and false, processing the
3423 tracepoint finishes very quickly and no data is gathered.
3425 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3426 for static tracepoints support.
3428 - GDBserver now supports x86_64 Windows 64-bit debugging.
3430 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3431 it understands register description.
3433 * The --batch flag now disables pagination and queries.
3435 * X86 general purpose registers
3437 GDB now supports reading/writing byte, word and double-word x86
3438 general purpose registers directly. This means you can use, say,
3439 $ah or $ax to refer, respectively, to the byte register AH and
3440 16-bit word register AX that are actually portions of the 32-bit
3441 register EAX or 64-bit register RAX.
3443 * The `commands' command now accepts a range of breakpoints to modify.
3444 A plain `commands' following a command that creates multiple
3445 breakpoints affects all the breakpoints set by that command. This
3446 applies to breakpoints set by `rbreak', and also applies when a
3447 single `break' command creates multiple breakpoints (e.g.,
3448 breakpoints on overloaded c++ functions).
3450 * The `rbreak' command now accepts a filename specification as part of
3451 its argument, limiting the functions selected by the regex to those
3452 in the specified file.
3454 * Support for remote debugging Windows and SymbianOS shared libraries
3455 from Unix hosts has been improved. Non Windows GDB builds now can
3456 understand target reported file names that follow MS-DOS based file
3457 system semantics, such as file names that include drive letters and
3458 use the backslash character as directory separator. This makes it
3459 possible to transparently use the "set sysroot" and "set
3460 solib-search-path" on Unix hosts to point as host copies of the
3461 target's shared libraries. See the new command "set
3462 target-file-system-kind" described below, and the "Commands to
3463 specify files" section in the user manual for more information.
3467 eval template, expressions...
3468 Convert the values of one or more expressions under the control
3469 of the string template to a command line, and call it.
3471 set target-file-system-kind unix|dos-based|auto
3472 show target-file-system-kind
3473 Set or show the assumed file system kind for target reported file
3476 save breakpoints <filename>
3477 Save all current breakpoint definitions to a file suitable for use
3478 in a later debugging session. To read the saved breakpoint
3479 definitions, use the `source' command.
3481 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3484 info static-tracepoint-markers
3485 Display information about static tracepoint markers in the target.
3487 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3488 Define a static tracepoint by probing a marker at the given
3489 function, line, address, or marker ID.
3493 Enable and disable observer mode.
3495 set may-write-registers on|off
3496 set may-write-memory on|off
3497 set may-insert-breakpoints on|off
3498 set may-insert-tracepoints on|off
3499 set may-insert-fast-tracepoints on|off
3500 set may-interrupt on|off
3501 Set individual permissions for GDB effects on the target. Note that
3502 some of these settings can have undesirable or surprising
3503 consequences, particularly when changed in the middle of a session.
3504 For instance, disabling the writing of memory can prevent
3505 breakpoints from being inserted, cause single-stepping to fail, or
3506 even crash your program, if you disable after breakpoints have been
3507 inserted. However, GDB should not crash.
3509 set record memory-query on|off
3510 show record memory-query
3511 Control whether to stop the inferior if memory changes caused
3512 by an instruction cannot be recorded.
3517 The disassemble command now supports "start,+length" form of two arguments.
3521 ** GDB now provides a new directory location, called the python directory,
3522 where Python scripts written for GDB can be installed. The location
3523 of that directory is <data-directory>/python, where <data-directory>
3524 is the GDB data directory. For more details, see section `Scripting
3525 GDB using Python' in the manual.
3527 ** The GDB Python API now has access to breakpoints, symbols, symbol
3528 tables, program spaces, inferiors, threads and frame's code blocks.
3529 Additionally, GDB Parameters can now be created from the API, and
3530 manipulated via set/show in the CLI.
3532 ** New functions gdb.target_charset, gdb.target_wide_charset,
3533 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3535 ** New exception gdb.GdbError.
3537 ** Pretty-printers are now also looked up in the current program space.
3539 ** Pretty-printers can now be individually enabled and disabled.
3541 ** GDB now looks for names of Python scripts to auto-load in a
3542 special section named `.debug_gdb_scripts', in addition to looking
3543 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3545 * Tracepoint actions were unified with breakpoint commands. In particular,
3546 there are no longer differences in "info break" output for breakpoints and
3547 tracepoints and the "commands" command can be used for both tracepoints and
3548 regular breakpoints.
3552 ARM Symbian arm*-*-symbianelf*
3554 * D language support.
3555 GDB now supports debugging programs written in the D programming
3558 * GDB now supports the extended ptrace interface for PowerPC which is
3559 available since Linux kernel version 2.6.34. This automatically enables
3560 any hardware breakpoints and additional hardware watchpoints available in
3561 the processor. The old ptrace interface exposes just one hardware
3562 watchpoint and no hardware breakpoints.
3564 * GDB is now able to use the Data Value Compare (DVC) register available on
3565 embedded PowerPC processors to implement in hardware simple watchpoint
3566 conditions of the form:
3568 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3570 This works in native GDB running on Linux kernels with the extended ptrace
3571 interface mentioned above.
3573 *** Changes in GDB 7.1
3577 ** Namespace Support
3579 GDB now supports importing of namespaces in C++. This enables the
3580 user to inspect variables from imported namespaces. Support for
3581 namepace aliasing has also been added. So, if a namespace is
3582 aliased in the current scope (e.g. namepace C=A; ) the user can
3583 print variables using the alias (e.g. (gdb) print C::x).
3587 All known bugs relating to the printing of virtual base class were
3588 fixed. It is now possible to call overloaded static methods using a
3593 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3594 and reinterpret_cast<> are now handled by the C++ expression parser.
3598 Xilinx MicroBlaze microblaze-*-*
3603 Xilinx MicroBlaze microblaze
3606 * Multi-program debugging.
3608 GDB now has support for multi-program (a.k.a. multi-executable or
3609 multi-exec) debugging. This allows for debugging multiple inferiors
3610 simultaneously each running a different program under the same GDB
3611 session. See "Debugging Multiple Inferiors and Programs" in the
3612 manual for more information. This implied some user visible changes
3613 in the multi-inferior support. For example, "info inferiors" now
3614 lists inferiors that are not running yet or that have exited
3615 already. See also "New commands" and "New options" below.
3617 * New tracing features
3619 GDB's tracepoint facility now includes several new features:
3621 ** Trace state variables
3623 GDB tracepoints now include support for trace state variables, which
3624 are variables managed by the target agent during a tracing
3625 experiment. They are useful for tracepoints that trigger each
3626 other, so for instance one tracepoint can count hits in a variable,
3627 and then a second tracepoint has a condition that is true when the
3628 count reaches a particular value. Trace state variables share the
3629 $-syntax of GDB convenience variables, and can appear in both
3630 tracepoint actions and condition expressions. Use the "tvariable"
3631 command to create, and "info tvariables" to view; see "Trace State
3632 Variables" in the manual for more detail.
3636 GDB now includes an option for defining fast tracepoints, which
3637 targets may implement more efficiently, such as by installing a jump
3638 into the target agent rather than a trap instruction. The resulting
3639 speedup can be by two orders of magnitude or more, although the
3640 tradeoff is that some program locations on some target architectures
3641 might not allow fast tracepoint installation, for instance if the
3642 instruction to be replaced is shorter than the jump. To request a
3643 fast tracepoint, use the "ftrace" command, with syntax identical to
3644 the regular trace command.
3646 ** Disconnected tracing
3648 It is now possible to detach GDB from the target while it is running
3649 a trace experiment, then reconnect later to see how the experiment
3650 is going. In addition, a new variable disconnected-tracing lets you
3651 tell the target agent whether to continue running a trace if the
3652 connection is lost unexpectedly.
3656 GDB now has the ability to save the trace buffer into a file, and
3657 then use that file as a target, similarly to you can do with
3658 corefiles. You can select trace frames, print data that was
3659 collected in them, and use tstatus to display the state of the
3660 tracing run at the moment that it was saved. To create a trace
3661 file, use "tsave <filename>", and to use it, do "target tfile
3664 ** Circular trace buffer
3666 You can ask the target agent to handle the trace buffer as a
3667 circular buffer, discarding the oldest trace frames to make room for
3668 newer ones, by setting circular-trace-buffer to on. This feature may
3669 not be available for all target agents.
3674 The disassemble command, when invoked with two arguments, now requires
3675 the arguments to be comma-separated.
3678 The info variables command now displays variable definitions. Files
3679 which only declare a variable are not shown.
3682 The source command is now capable of sourcing Python scripts.
3683 This feature is dependent on the debugger being build with Python
3686 Related to this enhancement is also the introduction of a new command
3687 "set script-extension" (see below).
3689 * New commands (for set/show, see "New options" below)
3691 record save [<FILENAME>]
3692 Save a file (in core file format) containing the process record
3693 execution log for replay debugging at a later time.
3695 record restore <FILENAME>
3696 Restore the process record execution log that was saved at an
3697 earlier time, for replay debugging.
3699 add-inferior [-copies <N>] [-exec <FILENAME>]
3702 clone-inferior [-copies <N>] [ID]
3703 Make a new inferior ready to execute the same program another
3704 inferior has loaded.
3709 maint info program-spaces
3710 List the program spaces loaded into GDB.
3712 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3713 show remote interrupt-sequence
3714 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3715 as the sequence to the remote target in order to interrupt the execution.
3716 Ctrl-C is a default. Some system prefers BREAK which is high level of
3717 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3718 Magic SysRq g. It is BREAK signal and character 'g'.
3720 set remote interrupt-on-connect [on | off]
3721 show remote interrupt-on-connect
3722 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3723 remote target when gdb connects to it. This is needed when you debug
3726 set remotebreak [on | off]
3728 Deprecated. Use "set/show remote interrupt-sequence" instead.
3730 tvariable $NAME [ = EXP ]
3731 Create or modify a trace state variable.
3734 List trace state variables and their values.
3736 delete tvariable $NAME ...
3737 Delete one or more trace state variables.
3740 Evaluate the given expressions without collecting anything into the
3741 trace buffer. (Valid in tracepoint actions only.)
3743 ftrace FN / FILE:LINE / *ADDR
3744 Define a fast tracepoint at the given function, line, or address.
3746 * New expression syntax
3748 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3749 GDB now parses 0b101010 identically with 42.
3753 set follow-exec-mode new|same
3754 show follow-exec-mode
3755 Control whether GDB reuses the same inferior across an exec call or
3756 creates a new one. This is useful to be able to restart the old
3757 executable after the inferior having done an exec call.
3759 set default-collect EXPR, ...
3760 show default-collect
3761 Define a list of expressions to be collected at each tracepoint.
3762 This is a useful way to ensure essential items are not overlooked,
3763 such as registers or a critical global variable.
3765 set disconnected-tracing
3766 show disconnected-tracing
3767 If set to 1, the target is instructed to continue tracing if it
3768 loses its connection to GDB. If 0, the target is to stop tracing
3771 set circular-trace-buffer
3772 show circular-trace-buffer
3773 If set to on, the target is instructed to use a circular trace buffer
3774 and discard the oldest trace frames instead of stopping the trace due
3775 to a full trace buffer. If set to off, the trace stops when the buffer
3776 fills up. Some targets may not support this.
3778 set script-extension off|soft|strict
3779 show script-extension
3780 If set to "off", the debugger does not perform any script language
3781 recognition, and all sourced files are assumed to be GDB scripts.
3782 If set to "soft" (the default), files are sourced according to
3783 filename extension, falling back to GDB scripts if the first
3785 If set to "strict", files are sourced according to filename extension.
3787 set ada trust-PAD-over-XVS on|off
3788 show ada trust-PAD-over-XVS
3789 If off, activate a workaround against a bug in the debugging information
3790 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3791 the GCC sources for more information about the GNAT encoding and
3792 PAD types in particular). It is always safe to set this option to
3793 off, but this introduces a slight performance penalty. The default
3796 * Python API Improvements
3798 ** GDB provides the new class gdb.LazyString. This is useful in
3799 some pretty-printing cases. The new method gdb.Value.lazy_string
3800 provides a simple way to create objects of this type.
3802 ** The fields returned by gdb.Type.fields now have an
3803 `is_base_class' attribute.
3805 ** The new method gdb.Type.range returns the range of an array type.
3807 ** The new method gdb.parse_and_eval can be used to parse and
3808 evaluate an expression.
3810 * New remote packets
3813 Define a trace state variable.
3816 Get the current value of a trace state variable.
3819 Set desired tracing behavior upon disconnection.
3822 Set the trace buffer to be linear or circular.
3825 Get data about the tracepoints currently in use.
3829 Process record now works correctly with hardware watchpoints.
3831 Multiple bug fixes have been made to the mips-irix port, making it
3832 much more reliable. In particular:
3833 - Debugging threaded applications is now possible again. Previously,
3834 GDB would hang while starting the program, or while waiting for
3835 the program to stop at a breakpoint.
3836 - Attaching to a running process no longer hangs.
3837 - An error occurring while loading a core file has been fixed.
3838 - Changing the value of the PC register now works again. This fixes
3839 problems observed when using the "jump" command, or when calling
3840 a function from GDB, or even when assigning a new value to $pc.
3841 - With the "finish" and "return" commands, the return value for functions
3842 returning a small array is now correctly printed.
3843 - It is now possible to break on shared library code which gets executed
3844 during a shared library init phase (code executed while executing
3845 their .init section). Previously, the breakpoint would have no effect.
3846 - GDB is now able to backtrace through the signal handler for
3847 non-threaded programs.
3849 PIE (Position Independent Executable) programs debugging is now supported.
3850 This includes debugging execution of PIC (Position Independent Code) shared
3851 libraries although for that, it should be possible to run such libraries as an
3854 *** Changes in GDB 7.0
3856 * GDB now has an interface for JIT compilation. Applications that
3857 dynamically generate code can create symbol files in memory and register
3858 them with GDB. For users, the feature should work transparently, and
3859 for JIT developers, the interface is documented in the GDB manual in the
3860 "JIT Compilation Interface" chapter.
3862 * Tracepoints may now be conditional. The syntax is as for
3863 breakpoints; either an "if" clause appended to the "trace" command,
3864 or the "condition" command is available. GDB sends the condition to
3865 the target for evaluation using the same bytecode format as is used
3866 for tracepoint actions.
3868 * The disassemble command now supports: an optional /r modifier, print the
3869 raw instructions in hex as well as in symbolic form, and an optional /m
3870 modifier to print mixed source+assembly.
3872 * Process record and replay
3874 In a architecture environment that supports ``process record and
3875 replay'', ``process record and replay'' target can record a log of
3876 the process execution, and replay it with both forward and reverse
3879 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3880 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3881 set execution-direction {forward|reverse}, for targets that support
3884 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3885 feature is available with a native GDB running on kernel version
3888 * GDB now has support for multi-byte and wide character sets on the
3889 target. Strings whose character type is wchar_t, char16_t, or
3890 char32_t are now correctly printed. GDB supports wide- and unicode-
3891 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3892 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3893 `printf'. This feature requires iconv to work properly; if your
3894 system does not have a working iconv, GDB can use GNU libiconv. See
3895 the installation instructions for more information.
3897 * GDB now supports automatic retrieval of shared library files from
3898 remote targets. To use this feature, specify a system root that begins
3899 with the `remote:' prefix, either via the `set sysroot' command or via
3900 the `--with-sysroot' configure-time option.
3902 * "info sharedlibrary" now takes an optional regex of libraries to show,
3903 and it now reports if a shared library has no debugging information.
3905 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3906 now complete on file names.
3908 * When completing in expressions, gdb will attempt to limit
3909 completions to allowable structure or union fields, where appropriate.
3910 For instance, consider:
3912 # struct example { int f1; double f2; };
3913 # struct example variable;
3916 If the user types TAB at the end of this command line, the available
3917 completions will be "f1" and "f2".
3919 * Inlined functions are now supported. They show up in backtraces, and
3920 the "step", "next", and "finish" commands handle them automatically.
3922 * GDB now supports the token-splicing (##) and stringification (#)
3923 operators when expanding macros. It also supports variable-arity
3926 * GDB now supports inspecting extra signal information, exported by
3927 the new $_siginfo convenience variable. The feature is currently
3928 implemented on linux ARM, i386 and amd64.
3930 * GDB can now display the VFP floating point registers and NEON vector
3931 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3932 can provide these registers (requires Linux 2.6.30 or later). Remote
3933 and simulator targets may also provide them.
3935 * New remote packets
3938 Search memory for a sequence of bytes.
3941 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3942 operation over reliable transport links. Use of this packet is
3943 controlled by the `set remote noack-packet' command.
3946 Kill the process with the specified process ID. Use this in preference
3947 to `k' when multiprocess protocol extensions are supported.
3950 Obtains additional operating system information
3954 Read or write additional signal information.
3956 * Removed remote protocol undocumented extension
3958 An undocumented extension to the remote protocol's `S' stop reply
3959 packet that permited the stub to pass a process id was removed.
3960 Remote servers should use the `T' stop reply packet instead.
3962 * GDB now supports multiple function calling conventions according to the
3963 DWARF-2 DW_AT_calling_convention function attribute.
3965 * The SH target utilizes the aforementioned change to distinguish between gcc
3966 and Renesas calling convention. It also adds the new CLI commands
3967 `set/show sh calling-convention'.
3969 * GDB can now read compressed debug sections, as produced by GNU gold
3970 with the --compress-debug-sections=zlib flag.
3972 * 64-bit core files are now supported on AIX.
3974 * Thread switching is now supported on Tru64.
3976 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3977 which will be allocated using malloc later in program execution.
3979 * The qXfer:libraries:read remote procotol packet now allows passing a
3980 list of section offsets.
3982 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3983 conditions handling signals delivered during attach or thread creation
3984 have also been fixed.
3986 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3987 From the user's standpoint, all unqualified instances of True and False
3988 are treated as the standard definitions, regardless of context.
3990 * GDB now parses C++ symbol and type names more flexibly. For
3993 template<typename T> class C { };
3996 GDB will now correctly handle all of:
3998 ptype C<char const *>
3999 ptype C<char const*>
4000 ptype C<const char *>
4001 ptype C<const char*>
4003 * New features in the GDB remote stub, gdbserver
4005 - The "--wrapper" command-line argument tells gdbserver to use a
4006 wrapper program to launch programs for debugging.
4008 - On PowerPC and S/390 targets, it is now possible to use a single
4009 gdbserver executable to debug both 32-bit and 64-bit programs.
4010 (This requires gdbserver itself to be built as a 64-bit executable.)
4012 - gdbserver uses the new noack protocol mode for TCP connections to
4013 reduce communications latency, if also supported and enabled in GDB.
4015 - Support for the sparc64-linux-gnu target is now included in
4018 - The amd64-linux build of gdbserver now supports debugging both
4019 32-bit and 64-bit programs.
4021 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4022 now support hardware watchpoints, and will use them automatically
4027 GDB now has support for scripting using Python. Whether this is
4028 available is determined at configure time.
4030 New GDB commands can now be written in Python.
4032 * Ada tasking support
4034 Ada tasks can now be inspected in GDB. The following commands have
4038 Print the list of Ada tasks.
4040 Print detailed information about task number N.
4042 Print the task number of the current task.
4044 Switch the context of debugging to task number N.
4046 * Support for user-defined prefixed commands. The "define" command can
4047 add new commands to existing prefixes, e.g. "target".
4049 * Multi-inferior, multi-process debugging.
4051 GDB now has generalized support for multi-inferior debugging. See
4052 "Debugging Multiple Inferiors" in the manual for more information.
4053 Although availability still depends on target support, the command
4054 set is more uniform now. The GNU/Linux specific multi-forks support
4055 has been migrated to this new framework. This implied some user
4056 visible changes; see "New commands" and also "Removed commands"
4059 * Target descriptions can now describe the target OS ABI. See the
4060 "Target Description Format" section in the user manual for more
4063 * Target descriptions can now describe "compatible" architectures
4064 to indicate that the target can execute applications for a different
4065 architecture in addition to those for the main target architecture.
4066 See the "Target Description Format" section in the user manual for
4069 * Multi-architecture debugging.
4071 GDB now includes general supports for debugging applications on
4072 hybrid systems that use more than one single processor architecture
4073 at the same time. Each such hybrid architecture still requires
4074 specific support to be added. The only hybrid architecture supported
4075 in this version of GDB is the Cell Broadband Engine.
4077 * GDB now supports integrated debugging of Cell/B.E. applications that
4078 use both the PPU and SPU architectures. To enable support for hybrid
4079 Cell/B.E. debugging, you need to configure GDB to support both the
4080 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4081 --enable-targets configure option.
4083 * Non-stop mode debugging.
4085 For some targets, GDB now supports an optional mode of operation in
4086 which you can examine stopped threads while other threads continue
4087 to execute freely. This is referred to as non-stop mode, with the
4088 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4089 section in the user manual for more information.
4091 To be able to support remote non-stop debugging, a remote stub needs
4092 to implement the non-stop mode remote protocol extensions, as
4093 described in the "Remote Non-Stop" section of the user manual. The
4094 GDB remote stub, gdbserver, has been adjusted to support these
4095 extensions on linux targets.
4097 * New commands (for set/show, see "New options" below)
4099 catch syscall [NAME(S) | NUMBER(S)]
4100 Catch system calls. Arguments, which should be names of system
4101 calls or their numbers, mean catch only those syscalls. Without
4102 arguments, every syscall will be caught. When the inferior issues
4103 any of the specified syscalls, GDB will stop and announce the system
4104 call, both when it is called and when its call returns. This
4105 feature is currently available with a native GDB running on the
4106 Linux Kernel, under the following architectures: x86, x86_64,
4107 PowerPC and PowerPC64.
4109 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4111 Search memory for a sequence of bytes.
4113 maint set python print-stack
4114 maint show python print-stack
4115 Show a stack trace when an error is encountered in a Python script.
4118 Invoke CODE by passing it to the Python interpreter.
4123 These allow macros to be defined, undefined, and listed
4127 Show operating system information about processes.
4130 List the inferiors currently under GDB's control.
4133 Switch focus to inferior number NUM.
4136 Detach from inferior number NUM.
4139 Kill inferior number NUM.
4143 set spu stop-on-load
4144 show spu stop-on-load
4145 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4147 set spu auto-flush-cache
4148 show spu auto-flush-cache
4149 Control whether to automatically flush the software-managed cache
4150 during Cell/B.E. debugging.
4152 set sh calling-convention
4153 show sh calling-convention
4154 Control the calling convention used when calling SH target functions.
4157 show debug timestamp
4158 Control display of timestamps with GDB debugging output.
4160 set disassemble-next-line
4161 show disassemble-next-line
4162 Control display of disassembled source lines or instructions when
4165 set remote noack-packet
4166 show remote noack-packet
4167 Set/show the use of remote protocol QStartNoAckMode packet. See above
4168 under "New remote packets."
4170 set remote query-attached-packet
4171 show remote query-attached-packet
4172 Control use of remote protocol `qAttached' (query-attached) packet.
4174 set remote read-siginfo-object
4175 show remote read-siginfo-object
4176 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4179 set remote write-siginfo-object
4180 show remote write-siginfo-object
4181 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4184 set remote reverse-continue
4185 show remote reverse-continue
4186 Control use of remote protocol 'bc' (reverse-continue) packet.
4188 set remote reverse-step
4189 show remote reverse-step
4190 Control use of remote protocol 'bs' (reverse-step) packet.
4192 set displaced-stepping
4193 show displaced-stepping
4194 Control displaced stepping mode. Displaced stepping is a way to
4195 single-step over breakpoints without removing them from the debuggee.
4196 Also known as "out-of-line single-stepping".
4199 show debug displaced
4200 Control display of debugging info for displaced stepping.
4202 maint set internal-error
4203 maint show internal-error
4204 Control what GDB does when an internal error is detected.
4206 maint set internal-warning
4207 maint show internal-warning
4208 Control what GDB does when an internal warning is detected.
4213 Use a wrapper program to launch programs for debugging.
4215 set multiple-symbols (all|ask|cancel)
4216 show multiple-symbols
4217 The value of this variable can be changed to adjust the debugger behavior
4218 when an expression or a breakpoint location contains an ambiguous symbol
4219 name (an overloaded function name, for instance).
4221 set breakpoint always-inserted
4222 show breakpoint always-inserted
4223 Keep breakpoints always inserted in the target, as opposed to inserting
4224 them when resuming the target, and removing them when the target stops.
4225 This option can improve debugger performance on slow remote targets.
4227 set arm fallback-mode (arm|thumb|auto)
4228 show arm fallback-mode
4229 set arm force-mode (arm|thumb|auto)
4231 These commands control how ARM GDB determines whether instructions
4232 are ARM or Thumb. The default for both settings is auto, which uses
4233 the current CPSR value for instructions without symbols; previous
4234 versions of GDB behaved as if "set arm fallback-mode arm".
4236 set disable-randomization
4237 show disable-randomization
4238 Standalone programs run with the virtual address space randomization enabled
4239 by default on some platforms. This option keeps the addresses stable across
4240 multiple debugging sessions.
4244 Control whether other threads are stopped or not when some thread hits
4249 Requests that asynchronous execution is enabled in the target, if available.
4250 In this case, it's possible to resume target in the background, and interact
4251 with GDB while the target is running. "show target-async" displays the
4252 current state of asynchronous execution of the target.
4254 set target-wide-charset
4255 show target-wide-charset
4256 The target-wide-charset is the name of the character set that GDB
4257 uses when printing characters whose type is wchar_t.
4259 set tcp auto-retry (on|off)
4261 set tcp connect-timeout
4262 show tcp connect-timeout
4263 These commands allow GDB to retry failed TCP connections to a remote stub
4264 with a specified timeout period; this is useful if the stub is launched
4265 in parallel with GDB but may not be ready to accept connections immediately.
4267 set libthread-db-search-path
4268 show libthread-db-search-path
4269 Control list of directories which GDB will search for appropriate
4272 set schedule-multiple (on|off)
4273 show schedule-multiple
4274 Allow GDB to resume all threads of all processes or only threads of
4275 the current process.
4279 Use more aggressive caching for accesses to the stack. This improves
4280 performance of remote debugging (particularly backtraces) without
4281 affecting correctness.
4283 set interactive-mode (on|off|auto)
4284 show interactive-mode
4285 Control whether GDB runs in interactive mode (on) or not (off).
4286 When in interactive mode, GDB waits for the user to answer all
4287 queries. Otherwise, GDB does not wait and assumes the default
4288 answer. When set to auto (the default), GDB determines which
4289 mode to use based on the stdin settings.
4294 For program forks, this is replaced by the new more generic `info
4295 inferiors' command. To list checkpoints, you can still use the
4296 `info checkpoints' command, which was an alias for the `info forks'
4300 Replaced by the new `inferior' command. To switch between
4301 checkpoints, you can still use the `restart' command, which was an
4302 alias for the `fork' command.
4305 This is removed, since some targets don't have a notion of
4306 processes. To switch between processes, you can still use the
4307 `inferior' command using GDB's own inferior number.
4310 For program forks, this is replaced by the new more generic `kill
4311 inferior' command. To delete a checkpoint, you can still use the
4312 `delete checkpoint' command, which was an alias for the `delete
4316 For program forks, this is replaced by the new more generic `detach
4317 inferior' command. To detach a checkpoint, you can still use the
4318 `detach checkpoint' command, which was an alias for the `detach
4321 * New native configurations
4323 x86/x86_64 Darwin i[34567]86-*-darwin*
4325 x86_64 MinGW x86_64-*-mingw*
4329 Lattice Mico32 lm32-*
4330 x86 DICOS i[34567]86-*-dicos*
4331 x86_64 DICOS x86_64-*-dicos*
4334 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4335 (mingw32ce) debugging.
4341 These commands were actually not implemented on any target.
4343 *** Changes in GDB 6.8
4345 * New native configurations
4347 NetBSD/hppa hppa*-*netbsd*
4348 Xtensa GNU/Linux xtensa*-*-linux*
4352 NetBSD/hppa hppa*-*-netbsd*
4353 Xtensa GNU/Lunux xtensa*-*-linux*
4355 * Change in command line behavior -- corefiles vs. process ids.
4357 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4358 attaching to process NUMBER fails, GDB no longer attempts to open a
4359 core file named NUMBER. Attaching to a program using the -c option
4360 is no longer supported. Instead, use the '-p' or '--pid' options.
4362 * GDB can now be built as a native debugger for debugging Windows x86
4363 (mingw32) Portable Executable (PE) programs.
4365 * Pending breakpoints no longer change their number when their address
4368 * GDB now supports breakpoints with multiple locations,
4369 including breakpoints on C++ constructors, inside C++ templates,
4370 and in inlined functions.
4372 * GDB's ability to debug optimized code has been improved. GDB more
4373 accurately identifies function bodies and lexical blocks that occupy
4374 more than one contiguous range of addresses.
4376 * Target descriptions can now describe registers for PowerPC.
4378 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4379 registers on PowerPC targets.
4381 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4382 targets even when the libthread_db library is not available.
4384 * The GDB remote stub, gdbserver, now supports the new file transfer
4385 commands (remote put, remote get, and remote delete).
4387 * The GDB remote stub, gdbserver, now supports run and attach in
4388 extended-remote mode.
4390 * hppa*64*-*-hpux11* target broken
4391 The debugger is unable to start a program and fails with the following
4392 error: "Error trying to get information about dynamic linker".
4393 The gdb-6.7 release is also affected.
4395 * GDB now supports the --enable-targets= configure option to allow
4396 building a single GDB executable that supports multiple remote
4397 target architectures.
4399 * GDB now supports debugging C and C++ programs which use the
4400 Decimal Floating Point extension. In addition, the PowerPC target
4401 now has a set of pseudo-registers to inspect decimal float values
4402 stored in two consecutive float registers.
4404 * The -break-insert MI command can optionally create pending
4407 * Improved support for debugging Ada
4408 Many improvements to the Ada language support have been made. These
4410 - Better support for Ada2005 interface types
4411 - Improved handling of arrays and slices in general
4412 - Better support for Taft-amendment types
4413 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4415 - Improved command completion in Ada
4418 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4423 set print frame-arguments (all|scalars|none)
4424 show print frame-arguments
4425 The value of this variable can be changed to control which argument
4426 values should be printed by the debugger when displaying a frame.
4431 Transfer files to and from a remote target, and delete remote files.
4438 Transfer files to and from a remote target, and delete remote files.
4440 * New remote packets
4447 Open, close, read, write, and delete files on the remote system.
4450 Attach to an existing process on the remote system, in extended-remote
4454 Run a new process on the remote system, in extended-remote mode.
4456 *** Changes in GDB 6.7
4458 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4459 bfd, libiberty and opcodes, as revealed by static analysis donated by
4460 Coverity, Inc. (http://scan.coverity.com).
4462 * When looking up multiply-defined global symbols, GDB will now prefer the
4463 symbol definition in the current shared library if it was built using the
4464 -Bsymbolic linker option.
4466 * When the Text User Interface (TUI) is not configured, GDB will now
4467 recognize the -tui command-line option and print a message that the TUI
4470 * The GDB remote stub, gdbserver, now has lower overhead for high
4471 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4473 * GDB for MIPS targets now autodetects whether a remote target provides
4474 32-bit or 64-bit register values.
4476 * Support for C++ member pointers has been improved.
4478 * GDB now understands XML target descriptions, which specify the
4479 target's overall architecture. GDB can read a description from
4480 a local file or over the remote serial protocol.
4482 * Vectors of single-byte data use a new integer type which is not
4483 automatically displayed as character or string data.
4485 * The /s format now works with the print command. It displays
4486 arrays of single-byte integers and pointers to single-byte integers
4489 * Target descriptions can now describe target-specific registers,
4490 for architectures which have implemented the support (currently
4491 only ARM, M68K, and MIPS).
4493 * GDB and the GDB remote stub, gdbserver, now support the XScale
4496 * The GDB remote stub, gdbserver, has been updated to support
4497 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4498 has been rewritten to use the standard GDB remote protocol.
4500 * GDB can now step into C++ functions which are called through thunks.
4502 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4504 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4505 layout. It also supports a TextSeg= and DataSeg= response when only
4506 segment base addresses (rather than offsets) are available.
4508 * The /i format now outputs any trailing branch delay slot instructions
4509 immediately following the last instruction within the count specified.
4511 * The GDB remote protocol "T" stop reply packet now supports a
4512 "library" response. Combined with the new "qXfer:libraries:read"
4513 packet, this response allows GDB to debug shared libraries on targets
4514 where the operating system manages the list of loaded libraries (e.g.
4515 Windows and SymbianOS).
4517 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4518 (DLLs) on Windows and Windows CE targets.
4520 * GDB now supports a faster verification that a .debug file matches its binary
4521 according to its build-id signature, if the signature is present.
4527 Enable or disable hardware flow control (RTS/CTS) on the serial port
4528 when debugging using remote targets.
4530 set mem inaccessible-by-default
4531 show mem inaccessible-by-default
4532 If the target supplies a memory map, for instance via the remote
4533 protocol's "qXfer:memory-map:read" packet, setting this variable
4534 prevents GDB from accessing memory outside the memory map. This
4535 is useful for targets with memory mapped registers or which react
4536 badly to accesses of unmapped address space.
4538 set breakpoint auto-hw
4539 show breakpoint auto-hw
4540 If the target supplies a memory map, for instance via the remote
4541 protocol's "qXfer:memory-map:read" packet, setting this variable
4542 lets GDB use hardware breakpoints automatically for memory regions
4543 where it can not use software breakpoints. This covers both the
4544 "break" command and internal breakpoints used for other commands
4545 including "next" and "finish".
4548 catch exception unhandled
4549 Stop the program execution when Ada exceptions are raised.
4552 Stop the program execution when an Ada assertion failed.
4556 Set an alternate system root for target files. This is a more
4557 general version of "set solib-absolute-prefix", which is now
4558 an alias to "set sysroot".
4561 Provide extended SPU facility status information. This set of
4562 commands is available only when debugging the Cell/B.E. SPU
4565 * New native configurations
4567 OpenBSD/sh sh*-*openbsd*
4570 unset tdesc filename
4572 Use the specified local file as an XML target description, and do
4573 not query the target for its built-in description.
4577 OpenBSD/sh sh*-*-openbsd*
4578 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4579 Toshiba Media Processor mep-elf
4581 * New remote packets
4584 Ignore the specified signals; pass them directly to the debugged program
4585 without stopping other threads or reporting them to GDB.
4587 qXfer:features:read:
4588 Read an XML target description from the target, which describes its
4593 Read or write contents of an spufs file on the target system. These
4594 packets are available only on the Cell/B.E. SPU architecture.
4596 qXfer:libraries:read:
4597 Report the loaded shared libraries. Combined with new "T" packet
4598 response, this packet allows GDB to debug shared libraries on
4599 targets where the operating system manages the list of loaded
4600 libraries (e.g. Windows and SymbianOS).
4604 Support for these obsolete configurations has been removed.
4612 i[34567]86-*-lynxos*
4613 i[34567]86-*-netware*
4614 i[34567]86-*-sco3.2v5*
4615 i[34567]86-*-sco3.2v4*
4617 i[34567]86-*-sysv4.2*
4620 i[34567]86-*-unixware2*
4621 i[34567]86-*-unixware*
4630 * Other removed features
4637 Various m68k-only ROM monitors.
4644 Various Renesas ROM monitors and debugging interfaces for SH and
4649 Support for a Macraigor serial interface to on-chip debugging.
4650 GDB does not directly support the newer parallel or USB
4655 A debug information format. The predecessor to DWARF 2 and
4656 DWARF 3, which are still supported.
4658 Support for the HP aCC compiler on HP-UX/PA-RISC
4660 SOM-encapsulated symbolic debugging information, automatic
4661 invocation of pxdb, and the aCC custom C++ ABI. This does not
4662 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4663 with aCC can still be debugged on an assembly level.
4665 MIPS ".pdr" sections
4667 A MIPS-specific format used to describe stack frame layout
4668 in debugging information.
4672 GDB could work with an older version of Guile to debug
4673 the interpreter and Scheme programs running in it.
4675 set mips stack-arg-size
4676 set mips saved-gpreg-size
4678 Use "set mips abi" to control parameter passing for MIPS.
4680 *** Changes in GDB 6.6
4685 Cell Broadband Engine SPU spu-elf
4687 * GDB can now be configured as a cross-debugger targeting native Windows
4688 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4689 running on a Windows system over TCP/IP to debug Windows programs.
4691 * The GDB remote stub, gdbserver, has been updated to support Windows and
4692 Cygwin debugging. Both single-threaded and multi-threaded programs are
4695 * The "set trust-readonly-sections" command works again. This command was
4696 broken in GDB 6.3, 6.4, and 6.5.
4698 * The "load" command now supports writing to flash memory, if the remote
4699 stub provides the required support.
4701 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4702 longer requires symbolic debug information (e.g. DWARF-2).
4707 unset substitute-path
4708 show substitute-path
4709 Manage a list of substitution rules that GDB uses to rewrite the name
4710 of the directories where the sources are located. This can be useful
4711 for instance when the sources were moved to a different location
4712 between compilation and debugging.
4716 Print each CLI command as it is executed. Each command is prefixed with
4717 a number of `+' symbols representing the nesting depth.
4718 The source command now has a `-v' option to enable the same feature.
4722 The ARM Demon monitor support (RDP protocol, "target rdp").
4724 Kernel Object Display, an embedded debugging feature which only worked with
4725 an obsolete version of Cisco IOS.
4727 The 'set download-write-size' and 'show download-write-size' commands.
4729 * New remote packets
4732 Tell a stub about GDB client features, and request remote target features.
4733 The first feature implemented is PacketSize, which allows the target to
4734 specify the size of packets it can handle - to minimize the number of
4735 packets required and improve performance when connected to a remote
4739 Fetch an OS auxilliary vector from the remote stub. This packet is a
4740 more efficient replacement for qPart:auxv:read.
4742 qXfer:memory-map:read:
4743 Fetch a memory map from the remote stub, including information about
4744 RAM, ROM, and flash memory devices.
4749 Erase and program a flash memory device.
4751 * Removed remote packets
4754 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4755 used it, and only gdbserver implemented it.
4757 *** Changes in GDB 6.5
4761 Renesas M32C/M16C m32c-elf
4763 Morpho Technologies ms1 ms1-elf
4767 init-if-undefined Initialize a convenience variable, but
4768 only if it doesn't already have a value.
4770 The following commands are presently only implemented for native GNU/Linux:
4772 checkpoint Save a snapshot of the program state.
4774 restart <n> Return the program state to a
4775 previously saved state.
4777 info checkpoints List currently saved checkpoints.
4779 delete-checkpoint <n> Delete a previously saved checkpoint.
4781 set|show detach-on-fork Tell gdb whether to detach from a newly
4782 forked process, or to keep debugging it.
4784 info forks List forks of the user program that
4785 are available to be debugged.
4787 fork <n> Switch to debugging one of several
4788 forks of the user program that are
4789 available to be debugged.
4791 delete-fork <n> Delete a fork from the list of forks
4792 that are available to be debugged (and
4793 kill the forked process).
4795 detach-fork <n> Delete a fork from the list of forks
4796 that are available to be debugged (and
4797 allow the process to continue).
4801 Morpho Technologies ms2 ms1-elf
4803 * Improved Windows host support
4805 GDB now builds as a cross debugger hosted on i686-mingw32, including
4806 native console support, and remote communications using either
4807 network sockets or serial ports.
4809 * Improved Modula-2 language support
4811 GDB can now print most types in the Modula-2 syntax. This includes:
4812 basic types, set types, record types, enumerated types, range types,
4813 pointer types and ARRAY types. Procedure var parameters are correctly
4814 printed and hexadecimal addresses and character constants are also
4815 written in the Modula-2 syntax. Best results can be obtained by using
4816 GNU Modula-2 together with the -gdwarf-2 command line option.
4820 The ARM rdi-share module.
4822 The Netware NLM debug server.
4824 *** Changes in GDB 6.4
4826 * New native configurations
4828 OpenBSD/arm arm*-*-openbsd*
4829 OpenBSD/mips64 mips64-*-openbsd*
4833 Morpho Technologies ms1 ms1-elf
4835 * New command line options
4837 --batch-silent As for --batch, but totally silent.
4838 --return-child-result The debugger will exist with the same value
4839 the child (debugged) program exited with.
4840 --eval-command COMMAND, -ex COMMAND
4841 Execute a single GDB CLI command. This may be
4842 specified multiple times and in conjunction
4843 with the --command (-x) option.
4845 * Deprecated commands removed
4847 The following commands, that were deprecated in 2000, have been
4851 set|show arm disassembly-flavor set|show arm disassembler
4852 othernames set arm disassembler
4853 set|show remotedebug set|show debug remote
4854 set|show archdebug set|show debug arch
4855 set|show eventdebug set|show debug event
4858 * New BSD user-level threads support
4860 It is now possible to debug programs using the user-level threads
4861 library on OpenBSD and FreeBSD. Currently supported (target)
4864 FreeBSD/amd64 x86_64-*-freebsd*
4865 FreeBSD/i386 i386-*-freebsd*
4866 OpenBSD/i386 i386-*-openbsd*
4868 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4869 are not yet supported.
4871 * New support for Matsushita MN10300 w/sim added
4872 (Work in progress). mn10300-elf.
4874 * REMOVED configurations and files
4876 VxWorks and the XDR protocol *-*-vxworks
4877 Motorola MCORE mcore-*-*
4878 National Semiconductor NS32000 ns32k-*-*
4880 * New "set print array-indexes" command
4882 After turning this setting "on", GDB prints the index of each element
4883 when displaying arrays. The default is "off" to preserve the previous
4886 * VAX floating point support
4888 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4890 * User-defined command support
4892 In addition to using $arg0..$arg9 for argument passing, it is now possible
4893 to use $argc to determine now many arguments have been passed. See the
4894 section on user-defined commands in the user manual for more information.
4896 *** Changes in GDB 6.3:
4898 * New command line option
4900 GDB now accepts -l followed by a number to set the timeout for remote
4903 * GDB works with GCC -feliminate-dwarf2-dups
4905 GDB now supports a more compact representation of DWARF-2 debug
4906 information using DW_FORM_ref_addr references. These are produced
4907 by GCC with the option -feliminate-dwarf2-dups and also by some
4908 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4909 to use -feliminate-dwarf2-dups.
4911 * Internationalization
4913 When supported by the host system, GDB will be built with
4914 internationalization (libintl). The task of marking up the sources is
4915 continued, we're looking forward to our first translation.
4919 Initial support for debugging programs compiled with the GNAT
4920 implementation of the Ada programming language has been integrated
4921 into GDB. In this release, support is limited to expression evaluation.
4923 * New native configurations
4925 GNU/Linux/m32r m32r-*-linux-gnu
4929 GDB's remote protocol now includes support for the 'p' packet. This
4930 packet is used to fetch individual registers from a remote inferior.
4932 * END-OF-LIFE registers[] compatibility module
4934 GDB's internal register infrastructure has been completely rewritten.
4935 The new infrastructure making possible the implementation of key new
4936 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4939 GDB 6.3 will be the last release to include the the registers[]
4940 compatibility module that allowed out-of-date configurations to
4941 continue to work. This change directly impacts the following
4951 powerpc bdm protocol
4953 Unless there is activity to revive these configurations, they will be
4954 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4956 * OBSOLETE configurations and files
4958 Configurations that have been declared obsolete in this release have
4959 been commented out. Unless there is activity to revive these
4960 configurations, the next release of GDB will have their sources
4961 permanently REMOVED.
4970 *** Changes in GDB 6.2.1:
4972 * MIPS `break main; run' gave an heuristic-fence-post warning
4974 When attempting to run even a simple program, a warning about
4975 heuristic-fence-post being hit would be reported. This problem has
4978 * MIPS IRIX 'long double' crashed GDB
4980 When examining a long double variable, GDB would get a segmentation
4981 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4982 IRIX long double values).
4986 A bug in the VAX stack code was causing problems with the "next"
4987 command. This problem has been fixed.
4989 *** Changes in GDB 6.2:
4991 * Fix for ``many threads''
4993 On GNU/Linux systems that use the NPTL threads library, a program
4994 rapidly creating and deleting threads would confuse GDB leading to the
4997 ptrace: No such process.
4998 thread_db_get_info: cannot get thread info: generic error
5000 This problem has been fixed.
5002 * "-async" and "-noasync" options removed.
5004 Support for the broken "-noasync" option has been removed (it caused
5007 * New ``start'' command.
5009 This command runs the program until the begining of the main procedure.
5011 * New BSD Kernel Data Access Library (libkvm) interface
5013 Using ``target kvm'' it is now possible to debug kernel core dumps and
5014 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5015 platforms. Currently supported (native-only) configurations are:
5017 FreeBSD/amd64 x86_64-*-freebsd*
5018 FreeBSD/i386 i?86-*-freebsd*
5019 NetBSD/i386 i?86-*-netbsd*
5020 NetBSD/m68k m68*-*-netbsd*
5021 NetBSD/sparc sparc-*-netbsd*
5022 OpenBSD/amd64 x86_64-*-openbsd*
5023 OpenBSD/i386 i?86-*-openbsd*
5024 OpenBSD/m68k m68*-openbsd*
5025 OpenBSD/sparc sparc-*-openbsd*
5027 * Signal trampoline code overhauled
5029 Many generic problems with GDB's signal handling code have been fixed.
5030 These include: backtraces through non-contiguous stacks; recognition
5031 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5032 call; backtrace through a signal trampoline; step into and out of
5033 signal handlers; and single-stepping in the signal trampoline.
5035 Please note that kernel bugs are a limiting factor here. These
5036 features have been shown to work on an s390 GNU/Linux system that
5037 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5039 * Cygwin support for DWARF 2 added.
5041 * New native configurations
5043 GNU/Linux/hppa hppa*-*-linux*
5044 OpenBSD/hppa hppa*-*-openbsd*
5045 OpenBSD/m68k m68*-*-openbsd*
5046 OpenBSD/m88k m88*-*-openbsd*
5047 OpenBSD/powerpc powerpc-*-openbsd*
5048 NetBSD/vax vax-*-netbsd*
5049 OpenBSD/vax vax-*-openbsd*
5051 * END-OF-LIFE frame compatibility module
5053 GDB's internal frame infrastructure has been completely rewritten.
5054 The new infrastructure making it possible to support key new features
5055 including DWARF 2 Call Frame Information. To aid in the task of
5056 migrating old configurations to this new infrastructure, a
5057 compatibility module, that allowed old configurations to continue to
5058 work, was also included.
5060 GDB 6.2 will be the last release to include this frame compatibility
5061 module. This change directly impacts the following configurations:
5071 Unless there is activity to revive these configurations, they will be
5072 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5074 * REMOVED configurations and files
5076 Sun 3, running SunOS 3 m68*-*-sunos3*
5077 Sun 3, running SunOS 4 m68*-*-sunos4*
5078 Sun 2, running SunOS 3 m68000-*-sunos3*
5079 Sun 2, running SunOS 4 m68000-*-sunos4*
5080 Motorola 680x0 running LynxOS m68*-*-lynxos*
5081 AT&T 3b1/Unix pc m68*-att-*
5082 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5083 decstation mips-dec-* mips-little-*
5084 riscos mips-*-riscos* mips-*-sysv*
5085 sonymips mips-sony-*
5086 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5088 *** Changes in GDB 6.1.1:
5090 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5092 The TUI (Text-mode User Interface) is now built as part of a default
5093 GDB configuration. It is enabled by either selecting the TUI with the
5094 command line option "-i=tui" or by running the separate "gdbtui"
5095 program. For more information on the TUI, see the manual "Debugging
5098 * Pending breakpoint support (also included in GDB 6.1)
5100 Support has been added to allow you to specify breakpoints in shared
5101 libraries that have not yet been loaded. If a breakpoint location
5102 cannot be found, and the "breakpoint pending" option is set to auto,
5103 GDB queries you if you wish to make the breakpoint pending on a future
5104 shared-library load. If and when GDB resolves the breakpoint symbol,
5105 the pending breakpoint is removed as one or more regular breakpoints
5108 Pending breakpoints are very useful for GCJ Java debugging.
5110 * Fixed ISO-C build problems
5112 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5113 non ISO-C code that stopped them being built using a more strict ISO-C
5114 compiler (e.g., IBM's C compiler).
5116 * Fixed build problem on IRIX 5
5118 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5119 wasn't able to compile compile on an IRIX 5 system.
5121 * Added execute permission to gdb/gdbserver/configure
5123 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5124 permission. This bug would cause configure to fail on a number of
5125 systems (Solaris, IRIX). Ref: server/519.
5127 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5129 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5130 has been updated to use constant array sizes.
5132 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5134 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5135 its generated DWARF Call Frame Info. This encoding was causing GDB to
5136 panic, that panic has been fixed. Ref: gdb/1628.
5138 * Fixed a problem when examining parameters in shared library code.
5140 When examining parameters in optimized shared library code generated
5141 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5142 not available''. GDB now correctly displays the variable's value.
5144 *** Changes in GDB 6.1:
5146 * Removed --with-mmalloc
5148 Support for the mmalloc memory manager has been removed, as it
5149 conflicted with the internal gdb byte cache.
5151 * Changes in AMD64 configurations
5153 The AMD64 target now includes the %cs and %ss registers. As a result
5154 the AMD64 remote protocol has changed; this affects the floating-point
5155 and SSE registers. If you rely on those registers for your debugging,
5156 you should upgrade gdbserver on the remote side.
5158 * Revised SPARC target
5160 The SPARC target has been completely revised, incorporating the
5161 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5162 support for LynxOS and SunOS 4 has been dropped. Calling functions
5163 from within GDB on operating systems with a non-executable stack
5164 (Solaris, OpenBSD) now works.
5168 GDB has a new C++ demangler which does a better job on the mangled
5169 names generated by current versions of g++. It also runs faster, so
5170 with this and other changes gdb should now start faster on large C++
5173 * DWARF 2 Location Expressions
5175 GDB support for location expressions has been extended to support function
5176 arguments and frame bases. Older versions of GDB could crash when they
5179 * C++ nested types and namespaces
5181 GDB's support for nested types and namespaces in C++ has been
5182 improved, especially if you use the DWARF 2 debugging format. (This
5183 is the default for recent versions of GCC on most platforms.)
5184 Specifically, if you have a class "Inner" defined within a class or
5185 namespace "Outer", then GDB realizes that the class's name is
5186 "Outer::Inner", not simply "Inner". This should greatly reduce the
5187 frequency of complaints about not finding RTTI symbols. In addition,
5188 if you are stopped at inside of a function defined within a namespace,
5189 GDB modifies its name lookup accordingly.
5191 * New native configurations
5193 NetBSD/amd64 x86_64-*-netbsd*
5194 OpenBSD/amd64 x86_64-*-openbsd*
5195 OpenBSD/alpha alpha*-*-openbsd*
5196 OpenBSD/sparc sparc-*-openbsd*
5197 OpenBSD/sparc64 sparc64-*-openbsd*
5199 * New debugging protocols
5201 M32R with SDI protocol m32r-*-elf*
5203 * "set prompt-escape-char" command deleted.
5205 The command "set prompt-escape-char" has been deleted. This command,
5206 and its very obscure effet on GDB's prompt, was never documented,
5207 tested, nor mentioned in the NEWS file.
5209 * OBSOLETE configurations and files
5211 Configurations that have been declared obsolete in this release have
5212 been commented out. Unless there is activity to revive these
5213 configurations, the next release of GDB will have their sources
5214 permanently REMOVED.
5216 Sun 3, running SunOS 3 m68*-*-sunos3*
5217 Sun 3, running SunOS 4 m68*-*-sunos4*
5218 Sun 2, running SunOS 3 m68000-*-sunos3*
5219 Sun 2, running SunOS 4 m68000-*-sunos4*
5220 Motorola 680x0 running LynxOS m68*-*-lynxos*
5221 AT&T 3b1/Unix pc m68*-att-*
5222 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5223 decstation mips-dec-* mips-little-*
5224 riscos mips-*-riscos* mips-*-sysv*
5225 sonymips mips-sony-*
5226 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5228 * REMOVED configurations and files
5230 SGI Irix-4.x mips-sgi-irix4 or iris4
5231 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5232 Z8000 simulator z8k-zilog-none or z8ksim
5233 Matsushita MN10200 w/simulator mn10200-*-*
5234 H8/500 simulator h8500-hitachi-hms or h8500hms
5235 HP/PA running BSD hppa*-*-bsd*
5236 HP/PA running OSF/1 hppa*-*-osf*
5237 HP/PA Pro target hppa*-*-pro*
5238 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5239 386BSD i[3456]86-*-bsd*
5240 Sequent family i[3456]86-sequent-sysv4*
5241 i[3456]86-sequent-sysv*
5242 i[3456]86-sequent-bsd*
5243 SPARC running LynxOS sparc-*-lynxos*
5244 SPARC running SunOS 4 sparc-*-sunos4*
5245 Tsqware Sparclet sparclet-*-*
5246 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5248 *** Changes in GDB 6.0:
5252 Support for debugging the Objective-C programming language has been
5253 integrated into GDB.
5255 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5257 DWARF 2's Call Frame Information makes available compiler generated
5258 information that more exactly describes the program's run-time stack.
5259 By using this information, GDB is able to provide more robust stack
5262 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5263 have been updated to use a new backtrace mechanism which includes
5264 DWARF 2 CFI support.
5268 GDB's remote protocol has been extended to include support for hosted
5269 file I/O (where the remote target uses GDB's file system). See GDB's
5270 remote protocol documentation for details.
5272 * All targets using the new architecture framework.
5274 All of GDB's targets have been updated to use the new internal
5275 architecture framework. The way is now open for future GDB releases
5276 to include cross-architecture native debugging support (i386 on amd64,
5279 * GNU/Linux's Thread Local Storage (TLS)
5281 GDB now includes support for for the GNU/Linux implementation of
5282 per-thread variables.
5284 * GNU/Linux's Native POSIX Thread Library (NPTL)
5286 GDB's thread code has been updated to work with either the new
5287 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5289 * Separate debug info.
5291 GDB, in conjunction with BINUTILS, now supports a mechanism for
5292 automatically loading debug information from a separate file. Instead
5293 of shipping full debug and non-debug versions of system libraries,
5294 system integrators can now instead ship just the stripped libraries
5295 and optional debug files.
5297 * DWARF 2 Location Expressions
5299 DWARF 2 Location Expressions allow the compiler to more completely
5300 describe the location of variables (even in optimized code) to the
5303 GDB now includes preliminary support for location expressions (support
5304 for DW_OP_piece is still missing).
5308 A number of long standing bugs that caused GDB to die while starting a
5309 Java application have been fixed. GDB's Java support is now
5310 considered "useable".
5312 * GNU/Linux support for fork, vfork, and exec.
5314 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5315 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5318 * GDB supports logging output to a file
5320 There are two new commands, "set logging" and "show logging", which can be
5321 used to capture GDB's output to a file.
5323 * The meaning of "detach" has changed for gdbserver
5325 The "detach" command will now resume the application, as documented. To
5326 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5329 * d10v, m68hc11 `regs' command deprecated
5331 The `info registers' command has been updated so that it displays the
5332 registers using a format identical to the old `regs' command.
5336 A new command, "maint set profile on/off", has been added. This command can
5337 be used to enable or disable profiling while running GDB, to profile a
5338 session or a set of commands. In addition there is a new configure switch,
5339 "--enable-profiling", which will cause GDB to be compiled with profiling
5340 data, for more informative profiling results.
5342 * Default MI syntax changed to "mi2".
5344 The default MI (machine interface) syntax, enabled by the command line
5345 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5346 "mi1", can be enabled by specifying the option "-i=mi1".
5348 Support for the original "mi0" syntax (included in GDB 5.0) has been
5351 Fix for gdb/192: removed extraneous space when displaying frame level.
5352 Fix for gdb/672: update changelist is now output in mi list format.
5353 Fix for gdb/702: a -var-assign that updates the value now shows up
5354 in a subsequent -var-update.
5356 * New native configurations.
5358 FreeBSD/amd64 x86_64-*-freebsd*
5360 * Multi-arched targets.
5362 HP/PA HPUX11 hppa*-*-hpux*
5363 Renesas M32R/D w/simulator m32r-*-elf*
5365 * OBSOLETE configurations and files
5367 Configurations that have been declared obsolete in this release have
5368 been commented out. Unless there is activity to revive these
5369 configurations, the next release of GDB will have their sources
5370 permanently REMOVED.
5372 Z8000 simulator z8k-zilog-none or z8ksim
5373 Matsushita MN10200 w/simulator mn10200-*-*
5374 H8/500 simulator h8500-hitachi-hms or h8500hms
5375 HP/PA running BSD hppa*-*-bsd*
5376 HP/PA running OSF/1 hppa*-*-osf*
5377 HP/PA Pro target hppa*-*-pro*
5378 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5379 Sequent family i[3456]86-sequent-sysv4*
5380 i[3456]86-sequent-sysv*
5381 i[3456]86-sequent-bsd*
5382 Tsqware Sparclet sparclet-*-*
5383 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5385 * REMOVED configurations and files
5388 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5389 IBM AIX PS/2 i[3456]86-*-aix
5390 i386 running Mach 3.0 i[3456]86-*-mach3*
5391 i386 running Mach i[3456]86-*-mach*
5392 i386 running OSF/1 i[3456]86-*osf1mk*
5393 HP/Apollo 68k Family m68*-apollo*-sysv*,
5395 m68*-hp-bsd*, m68*-hp-hpux*
5396 Argonaut Risc Chip (ARC) arc-*-*
5397 Mitsubishi D30V d30v-*-*
5398 Fujitsu FR30 fr30-*-elf*
5399 OS/9000 i[34]86-*-os9k
5400 I960 with MON960 i960-*-coff
5402 * MIPS $fp behavior changed
5404 The convenience variable $fp, for the MIPS, now consistently returns
5405 the address of the current frame's base. Previously, depending on the
5406 context, $fp could refer to either $sp or the current frame's base
5407 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5408 The GNU Source-Level Debugger''.
5410 *** Changes in GDB 5.3:
5412 * GNU/Linux shared library multi-threaded performance improved.
5414 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5415 `/proc', in preference to `ptrace' for memory reads. This may result
5416 in an improvement in the start-up time of multi-threaded, shared
5417 library applications when run under GDB. One GDB user writes: ``loads
5418 shared libs like mad''.
5420 * ``gdbserver'' now supports multi-threaded applications on some targets
5422 Support for debugging multi-threaded applications which use
5423 the GNU/Linux LinuxThreads package has been added for
5424 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5425 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5427 * GDB now supports C/C++ preprocessor macros.
5429 GDB now expands preprocessor macro invocations in C/C++ expressions,
5430 and provides various commands for showing macro definitions and how
5433 The new command `macro expand EXPRESSION' expands any macro
5434 invocations in expression, and shows the result.
5436 The new command `show macro MACRO-NAME' shows the definition of the
5437 macro named MACRO-NAME, and where it was defined.
5439 Most compilers don't include information about macros in the debugging
5440 information by default. In GCC 3.1, for example, you need to compile
5441 your program with the options `-gdwarf-2 -g3'. If the macro
5442 information is present in the executable, GDB will read it.
5444 * Multi-arched targets.
5446 DEC Alpha (partial) alpha*-*-*
5447 DEC VAX (partial) vax-*-*
5449 National Semiconductor NS32000 (partial) ns32k-*-*
5450 Motorola 68000 (partial) m68k-*-*
5451 Motorola MCORE mcore-*-*
5455 Fujitsu FRV architecture added by Red Hat frv*-*-*
5458 * New native configurations
5460 Alpha NetBSD alpha*-*-netbsd*
5461 SH NetBSD sh*-*-netbsdelf*
5462 MIPS NetBSD mips*-*-netbsd*
5463 UltraSPARC NetBSD sparc64-*-netbsd*
5465 * OBSOLETE configurations and files
5467 Configurations that have been declared obsolete in this release have
5468 been commented out. Unless there is activity to revive these
5469 configurations, the next release of GDB will have their sources
5470 permanently REMOVED.
5472 Mitsubishi D30V d30v-*-*
5473 OS/9000 i[34]86-*-os9k
5474 IBM AIX PS/2 i[3456]86-*-aix
5475 Fujitsu FR30 fr30-*-elf*
5476 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5477 Argonaut Risc Chip (ARC) arc-*-*
5478 i386 running Mach 3.0 i[3456]86-*-mach3*
5479 i386 running Mach i[3456]86-*-mach*
5480 i386 running OSF/1 i[3456]86-*osf1mk*
5481 HP/Apollo 68k Family m68*-apollo*-sysv*,
5483 m68*-hp-bsd*, m68*-hp-hpux*
5484 I960 with MON960 i960-*-coff
5486 * OBSOLETE languages
5488 CHILL, a Pascal like language used by telecommunications companies.
5490 * REMOVED configurations and files
5492 AMD 29k family via UDI a29k-amd-udi, udi29k
5493 A29K VxWorks a29k-*-vxworks
5494 AMD 29000 embedded, using EBMON a29k-none-none
5495 AMD 29000 embedded with COFF a29k-none-coff
5496 AMD 29000 embedded with a.out a29k-none-aout
5498 testsuite/gdb.hp/gdb.threads-hp/ directory
5500 * New command "set max-user-call-depth <nnn>"
5502 This command allows the user to limit the call depth of user-defined
5503 commands. The default is 1024.
5505 * Changes in FreeBSD/i386 native debugging.
5507 Support for the "generate-core-file" has been added.
5509 * New commands "dump", "append", and "restore".
5511 These commands allow data to be copied from target memory
5512 to a bfd-format or binary file (dump and append), and back
5513 from a file into memory (restore).
5515 * Improved "next/step" support on multi-processor Alpha Tru64.
5517 The previous single-step mechanism could cause unpredictable problems,
5518 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5519 of a software single-step mechanism prevents this.
5521 *** Changes in GDB 5.2.1:
5529 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5530 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5531 Fix, by Joel Brobecker imported from mainline.
5533 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5534 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5535 Fix, by Fred Fish, imported from mainline.
5537 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5538 Surprisingly enough, it works now.
5539 By Michal Ludvig, imported from mainline.
5541 i386 hardware watchpoint support:
5542 avoid misses on second run for some targets.
5543 By Pierre Muller, imported from mainline.
5545 *** Changes in GDB 5.2:
5547 * New command "set trust-readonly-sections on[off]".
5549 This command is a hint that tells gdb that read-only sections
5550 really are read-only (ie. that their contents will not change).
5551 In this mode, gdb will go to the object file rather than the
5552 target to read memory from read-only sections (such as ".text").
5553 This can be a significant performance improvement on some
5554 (notably embedded) targets.
5556 * New command "generate-core-file" (or "gcore").
5558 This new gdb command allows the user to drop a core file of the child
5559 process state at any time. So far it's been implemented only for
5560 GNU/Linux and Solaris, but should be relatively easily ported to other
5561 hosts. Argument is core file name (defaults to core.<pid>).
5563 * New command line option
5565 GDB now accepts --pid or -p followed by a process id.
5567 * Change in command line behavior -- corefiles vs. process ids.
5569 There is a subtle behavior in the way in which GDB handles
5570 command line arguments. The first non-flag argument is always
5571 a program to debug, but the second non-flag argument may either
5572 be a corefile or a process id. Previously, GDB would attempt to
5573 open the second argument as a corefile, and if that failed, would
5574 issue a superfluous error message and then attempt to attach it as
5575 a process. Now, if the second argument begins with a non-digit,
5576 it will be treated as a corefile. If it begins with a digit,
5577 GDB will attempt to attach it as a process, and if no such process
5578 is found, will then attempt to open it as a corefile.
5580 * Changes in ARM configurations.
5582 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5583 configuration is fully multi-arch.
5585 * New native configurations
5587 ARM NetBSD arm*-*-netbsd*
5588 x86 OpenBSD i[3456]86-*-openbsd*
5589 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5590 Sparc64 running FreeBSD sparc64-*-freebsd*
5594 Sanyo XStormy16 xstormy16-elf
5596 * OBSOLETE configurations and files
5598 Configurations that have been declared obsolete in this release have
5599 been commented out. Unless there is activity to revive these
5600 configurations, the next release of GDB will have their sources
5601 permanently REMOVED.
5603 AMD 29k family via UDI a29k-amd-udi, udi29k
5604 A29K VxWorks a29k-*-vxworks
5605 AMD 29000 embedded, using EBMON a29k-none-none
5606 AMD 29000 embedded with COFF a29k-none-coff
5607 AMD 29000 embedded with a.out a29k-none-aout
5609 testsuite/gdb.hp/gdb.threads-hp/ directory
5611 * REMOVED configurations and files
5613 TI TMS320C80 tic80-*-*
5615 PowerPC Solaris powerpcle-*-solaris*
5616 PowerPC Windows NT powerpcle-*-cygwin32
5617 PowerPC Netware powerpc-*-netware*
5618 Harris/CXUX m88k m88*-harris-cxux*
5619 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5620 ns32k-utek-sysv* ns32k-utek-*
5621 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5622 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5623 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5624 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5625 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5627 * Changes to command line processing
5629 The new `--args' feature can be used to specify command-line arguments
5630 for the inferior from gdb's command line.
5632 * Changes to key bindings
5634 There is a new `operate-and-get-next' function bound to `C-o'.
5636 *** Changes in GDB 5.1.1
5638 Fix compile problem on DJGPP.
5640 Fix a problem with floating-point registers on the i386 being
5643 Fix to stop GDB crashing on .debug_str debug info.
5645 Numerous documentation fixes.
5647 Numerous testsuite fixes.
5649 *** Changes in GDB 5.1:
5651 * New native configurations
5653 Alpha FreeBSD alpha*-*-freebsd*
5654 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5655 MIPS GNU/Linux mips*-*-linux*
5656 MIPS SGI Irix 6.x mips*-sgi-irix6*
5657 ia64 AIX ia64-*-aix*
5658 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5662 Motorola 68HC11 and 68HC12 m68hc11-elf
5664 UltraSparc running GNU/Linux sparc64-*-linux*
5666 * OBSOLETE configurations and files
5668 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5669 Harris/CXUX m88k m88*-harris-cxux*
5670 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5671 ns32k-utek-sysv* ns32k-utek-*
5672 TI TMS320C80 tic80-*-*
5674 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5675 PowerPC Solaris powerpcle-*-solaris*
5676 PowerPC Windows NT powerpcle-*-cygwin32
5677 PowerPC Netware powerpc-*-netware*
5678 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5679 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5680 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5681 Apple Macintosh (MPW) host N/A
5683 stuff.c (Program to stuff files into a specially prepared space in kdb)
5684 kdb-start.c (Main loop for the standalone kernel debugger)
5686 Configurations that have been declared obsolete in this release have
5687 been commented out. Unless there is activity to revive these
5688 configurations, the next release of GDB will have their sources
5689 permanently REMOVED.
5691 * REMOVED configurations and files
5693 Altos 3068 m68*-altos-*
5694 Convex c1-*-*, c2-*-*
5696 ARM RISCix arm-*-* (as host)
5700 * GDB has been converted to ISO C.
5702 GDB's source code has been converted to ISO C. In particular, the
5703 sources are fully protoized, and rely on standard headers being
5708 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5710 * The MI enabled by default.
5712 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5713 revised and enabled by default. Packages which use GDB as a debugging
5714 engine behind a UI or another front end are encouraged to switch to
5715 using the GDB/MI interface, instead of the old annotations interface
5716 which is now deprecated.
5718 * Support for debugging Pascal programs.
5720 GDB now includes support for debugging Pascal programs. The following
5721 main features are supported:
5723 - Pascal-specific data types such as sets;
5725 - automatic recognition of Pascal sources based on file-name
5728 - Pascal-style display of data types, variables, and functions;
5730 - a Pascal expression parser.
5732 However, some important features are not yet supported.
5734 - Pascal string operations are not supported at all;
5736 - there are some problems with boolean types;
5738 - Pascal type hexadecimal constants are not supported
5739 because they conflict with the internal variables format;
5741 - support for Pascal objects and classes is not full yet;
5743 - unlike Pascal, GDB is case-sensitive for symbol names.
5745 * Changes in completion.
5747 Commands such as `shell', `run' and `set args', which pass arguments
5748 to inferior programs, now complete on file names, similar to what
5749 users expect at the shell prompt.
5751 Commands which accept locations, such as `disassemble', `print',
5752 `breakpoint', `until', etc. now complete on filenames as well as
5753 program symbols. Thus, if you type "break foob TAB", and the source
5754 files linked into the programs include `foobar.c', that file name will
5755 be one of the candidates for completion. However, file names are not
5756 considered for completion after you typed a colon that delimits a file
5757 name from a name of a function in that file, as in "break foo.c:bar".
5759 `set demangle-style' completes on available demangling styles.
5761 * New platform-independent commands:
5763 It is now possible to define a post-hook for a command as well as a
5764 hook that runs before the command. For more details, see the
5765 documentation of `hookpost' in the GDB manual.
5767 * Changes in GNU/Linux native debugging.
5769 Support for debugging multi-threaded programs has been completely
5770 revised for all platforms except m68k and sparc. You can now debug as
5771 many threads as your system allows you to have.
5773 Attach/detach is supported for multi-threaded programs.
5775 Support for SSE registers was added for x86. This doesn't work for
5776 multi-threaded programs though.
5778 * Changes in MIPS configurations.
5780 Multi-arch support is enabled for all MIPS configurations.
5782 GDB can now be built as native debugger on SGI Irix 6.x systems for
5783 debugging n32 executables. (Debugging 64-bit executables is not yet
5786 * Unified support for hardware watchpoints in all x86 configurations.
5788 Most (if not all) native x86 configurations support hardware-assisted
5789 breakpoints and watchpoints in a unified manner. This support
5790 implements debug register sharing between watchpoints, which allows to
5791 put a virtually infinite number of watchpoints on the same address,
5792 and also supports watching regions up to 16 bytes with several debug
5795 The new maintenance command `maintenance show-debug-regs' toggles
5796 debugging print-outs in functions that insert, remove, and test
5797 watchpoints and hardware breakpoints.
5799 * Changes in the DJGPP native configuration.
5801 New command ``info dos sysinfo'' displays assorted information about
5802 the CPU, OS, memory, and DPMI server.
5804 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5805 display information about segment descriptors stored in GDT, LDT, and
5808 New commands ``info dos pde'' and ``info dos pte'' display entries
5809 from Page Directory and Page Tables (for now works with CWSDPMI only).
5810 New command ``info dos address-pte'' displays the Page Table entry for
5811 a given linear address.
5813 GDB can now pass command lines longer than 126 characters to the
5814 program being debugged (requires an update to the libdbg.a library
5815 which is part of the DJGPP development kit).
5817 DWARF2 debug info is now supported.
5819 It is now possible to `step' and `next' through calls to `longjmp'.
5821 * Changes in documentation.
5823 All GDB documentation was converted to GFDL, the GNU Free
5824 Documentation License.
5826 Tracepoints-related commands are now fully documented in the GDB
5829 TUI, the Text-mode User Interface, is now documented in the manual.
5831 Tracepoints-related commands are now fully documented in the GDB
5834 The "GDB Internals" manual now has an index. It also includes
5835 documentation of `ui_out' functions, GDB coding standards, x86
5836 hardware watchpoints, and memory region attributes.
5838 * GDB's version number moved to ``version.in''
5840 The Makefile variable VERSION has been replaced by the file
5841 ``version.in''. People creating GDB distributions should update the
5842 contents of this file.
5846 GUD support is now a standard part of the EMACS distribution.
5848 *** Changes in GDB 5.0:
5850 * Improved support for debugging FP programs on x86 targets
5852 Unified and much-improved support for debugging floating-point
5853 programs on all x86 targets. In particular, ``info float'' now
5854 displays the FP registers in the same format on all x86 targets, with
5855 greater level of detail.
5857 * Improvements and bugfixes in hardware-assisted watchpoints
5859 It is now possible to watch array elements, struct members, and
5860 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5861 on x86 targets no longer erroneously trigger when the address is
5864 * Improvements in the native DJGPP version of GDB
5866 The distribution now includes all the scripts and auxiliary files
5867 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5868 machines ``out of the box''.
5870 The DJGPP version can now debug programs that use signals. It is
5871 possible to catch signals that happened in the debuggee, deliver
5872 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5873 would kill the program being debugged.) Programs that hook hardware
5874 interrupts (keyboard, timer, etc.) can also be debugged.
5876 It is now possible to debug DJGPP programs that redirect their
5877 standard handles or switch them to raw (as opposed to cooked) mode, or
5878 even close them. The command ``run < foo > bar'' works as expected,
5879 and ``info terminal'' reports useful information about the debuggee's
5880 terminal, including raw/cooked mode, redirection, etc.
5882 The DJGPP version now uses termios functions for console I/O, which
5883 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5886 DOS-style file names with drive letters are now fully supported by
5889 It is now possible to debug DJGPP programs that switch their working
5890 directory. It is also possible to rerun the debuggee any number of
5891 times without restarting GDB; thus, you can use the same setup,
5892 breakpoints, etc. for many debugging sessions.
5894 * New native configurations
5896 ARM GNU/Linux arm*-*-linux*
5897 PowerPC GNU/Linux powerpc-*-linux*
5901 Motorola MCore mcore-*-*
5902 x86 VxWorks i[3456]86-*-vxworks*
5903 PowerPC VxWorks powerpc-*-vxworks*
5904 TI TMS320C80 tic80-*-*
5906 * OBSOLETE configurations
5908 Altos 3068 m68*-altos-*
5909 Convex c1-*-*, c2-*-*
5911 ARM RISCix arm-*-* (as host)
5914 Configurations that have been declared obsolete will be commented out,
5915 but the code will be left in place. If there is no activity to revive
5916 these configurations before the next release of GDB, the sources will
5917 be permanently REMOVED.
5919 * Gould support removed
5921 Support for the Gould PowerNode and NP1 has been removed.
5923 * New features for SVR4
5925 On SVR4 native platforms (such as Solaris), if you attach to a process
5926 without first loading a symbol file, GDB will now attempt to locate and
5927 load symbols from the running process's executable file.
5929 * Many C++ enhancements
5931 C++ support has been greatly improved. Overload resolution now works properly
5932 in almost all cases. RTTI support is on the way.
5934 * Remote targets can connect to a sub-program
5936 A popen(3) style serial-device has been added. This device starts a
5937 sub-process (such as a stand-alone simulator) and then communicates
5938 with that. The sub-program to run is specified using the syntax
5939 ``|<program> <args>'' vis:
5941 (gdb) set remotedebug 1
5942 (gdb) target extended-remote |mn10300-elf-sim program-args
5944 * MIPS 64 remote protocol
5946 A long standing bug in the mips64 remote protocol where by GDB
5947 expected certain 32 bit registers (ex SR) to be transfered as 32
5948 instead of 64 bits has been fixed.
5950 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5951 added to provide backward compatibility with older versions of GDB.
5953 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5955 The command ``set remotebinarydownload'' command has been replaced by
5956 ``set remote X-packet''. Other commands in ``set remote'' family
5957 include ``set remote P-packet''.
5959 * Breakpoint commands accept ranges.
5961 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5962 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5963 ``tracepoint passcount'' also accepts a range of tracepoints.
5965 * ``apropos'' command added.
5967 The ``apropos'' command searches through command names and
5968 documentation strings, printing out matches, making it much easier to
5969 try to find a command that does what you are looking for.
5973 A new machine oriented interface (MI) has been added to GDB. This
5974 interface is designed for debug environments running GDB as a separate
5975 process. This is part of the long term libGDB project. See the
5976 "GDB/MI" chapter of the GDB manual for further information. It can be
5977 enabled by configuring with:
5979 .../configure --enable-gdbmi
5981 *** Changes in GDB-4.18:
5983 * New native configurations
5985 HP-UX 10.20 hppa*-*-hpux10.20
5986 HP-UX 11.x hppa*-*-hpux11.0*
5987 M68K GNU/Linux m68*-*-linux*
5991 Fujitsu FR30 fr30-*-elf*
5992 Intel StrongARM strongarm-*-*
5993 Mitsubishi D30V d30v-*-*
5995 * OBSOLETE configurations
5997 Gould PowerNode, NP1 np1-*-*, pn-*-*
5999 Configurations that have been declared obsolete will be commented out,
6000 but the code will be left in place. If there is no activity to revive
6001 these configurations before the next release of GDB, the sources will
6002 be permanently REMOVED.
6006 As a compatibility experiment, GDB's source files buildsym.h and
6007 buildsym.c have been converted to pure standard C, no longer
6008 containing any K&R compatibility code. We believe that all systems in
6009 use today either come with a standard C compiler, or have a GCC port
6010 available. If this is not true, please report the affected
6011 configuration to bug-gdb@gnu.org immediately. See the README file for
6012 information about getting a standard C compiler if you don't have one
6017 GDB now uses readline 2.2.
6019 * set extension-language
6021 You can now control the mapping between filename extensions and source
6022 languages by using the `set extension-language' command. For instance,
6023 you can ask GDB to treat .c files as C++ by saying
6024 set extension-language .c c++
6025 The command `info extensions' lists all of the recognized extensions
6026 and their associated languages.
6028 * Setting processor type for PowerPC and RS/6000
6030 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6031 you can use the `set processor' command to specify what variant of the
6032 PowerPC family you are debugging. The command
6036 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6037 following PowerPC and RS6000 variants:
6039 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6040 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6042 403GC IBM PowerPC 403GC
6043 505 Motorola PowerPC 505
6044 860 Motorola PowerPC 860 or 850
6045 601 Motorola PowerPC 601
6046 602 Motorola PowerPC 602
6047 603 Motorola/IBM PowerPC 603 or 603e
6048 604 Motorola PowerPC 604 or 604e
6049 750 Motorola/IBM PowerPC 750 or 750
6051 At the moment, this command just tells GDB what to name the
6052 special-purpose processor registers. Since almost all the affected
6053 registers are inaccessible to user-level programs, this command is
6054 only useful for remote debugging in its present form.
6058 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6059 more extensive support for HP-UX. Added features include shared
6060 library support, kernel threads and hardware watchpoints for 11.00,
6061 support for HP's ANSI C and C++ compilers, and a compatibility mode
6062 for xdb and dbx commands.
6066 HP's donation includes the new concept of catchpoints, which is a
6067 generalization of the old catch command. On HP-UX, it is now possible
6068 to catch exec, fork, and vfork, as well as library loading.
6070 This means that the existing catch command has changed; its first
6071 argument now specifies the type of catch to be set up. See the
6072 output of "help catch" for a list of catchpoint types.
6074 * Debugging across forks
6076 On HP-UX, you can choose which process to debug when a fork() happens
6081 HP has donated a curses-based terminal user interface (TUI). To get
6082 it, build with --enable-tui. Although this can be enabled for any
6083 configuration, at present it only works for native HP debugging.
6085 * GDB remote protocol additions
6087 A new protocol packet 'X' that writes binary data is now available.
6088 Default behavior is to try 'X', then drop back to 'M' if the stub
6089 fails to respond. The settable variable `remotebinarydownload'
6090 allows explicit control over the use of 'X'.
6092 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6093 full 64-bit address. The command
6095 set remoteaddresssize 32
6097 can be used to revert to the old behaviour. For existing remote stubs
6098 the change should not be noticed, as the additional address information
6101 In order to assist in debugging stubs, you may use the maintenance
6102 command `packet' to send any text string to the stub. For instance,
6104 maint packet heythere
6106 sends the packet "$heythere#<checksum>". Note that it is very easy to
6107 disrupt a debugging session by sending the wrong packet at the wrong
6110 The compare-sections command allows you to compare section data on the
6111 target to what is in the executable file without uploading or
6112 downloading, by comparing CRC checksums.
6114 * Tracing can collect general expressions
6116 You may now collect general expressions at tracepoints. This requires
6117 further additions to the target-side stub; see tracepoint.c and
6118 doc/agentexpr.texi for further details.
6120 * mask-address variable for Mips
6122 For Mips targets, you may control the zeroing of the upper 32 bits of
6123 a 64-bit address by entering `set mask-address on'. This is mainly
6124 of interest to users of embedded R4xxx and R5xxx processors.
6126 * Higher serial baud rates
6128 GDB's serial code now allows you to specify baud rates 57600, 115200,
6129 230400, and 460800 baud. (Note that your host system may not be able
6130 to achieve all of these rates.)
6134 The i960 configuration now includes an initial implementation of a
6135 builtin simulator, contributed by Jim Wilson.
6138 *** Changes in GDB-4.17:
6140 * New native configurations
6142 Alpha GNU/Linux alpha*-*-linux*
6143 Unixware 2.x i[3456]86-unixware2*
6144 Irix 6.x mips*-sgi-irix6*
6145 PowerPC GNU/Linux powerpc-*-linux*
6146 PowerPC Solaris powerpcle-*-solaris*
6147 Sparc GNU/Linux sparc-*-linux*
6148 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6152 Argonaut Risc Chip (ARC) arc-*-*
6153 Hitachi H8/300S h8300*-*-*
6154 Matsushita MN10200 w/simulator mn10200-*-*
6155 Matsushita MN10300 w/simulator mn10300-*-*
6156 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6157 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6158 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6159 Mitsubishi D10V w/simulator d10v-*-*
6160 Mitsubishi M32R/D w/simulator m32r-*-elf*
6161 Tsqware Sparclet sparclet-*-*
6162 NEC V850 w/simulator v850-*-*
6164 * New debugging protocols
6166 ARM with RDI protocol arm*-*-*
6167 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6168 DDB and LSI variants of PMON protocol mips*-*-*
6169 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6170 PowerPC with SDS protocol powerpc{,le}-*-eabi
6171 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6175 All configurations can now understand and use the DWARF 2 debugging
6176 format. The choice is automatic, if the symbol file contains DWARF 2
6181 GDB now includes basic Java language support. This support is
6182 only useful with Java compilers that produce native machine code.
6184 * solib-absolute-prefix and solib-search-path
6186 For SunOS and SVR4 shared libraries, you may now set the prefix for
6187 loading absolute shared library symbol files, and the search path for
6188 locating non-absolute shared library symbol files.
6190 * Live range splitting
6192 GDB can now effectively debug code for which GCC has performed live
6193 range splitting as part of its optimization. See gdb/doc/LRS for
6194 more details on the expected format of the stabs information.
6198 GDB's support for the GNU Hurd, including thread debugging, has been
6199 updated to work with current versions of the Hurd.
6203 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6204 instruction set. ARM GDB automatically detects when Thumb
6205 instructions are in use, and adjusts disassembly and backtracing
6210 GDB's MIPS target configurations now handle the MIP16 16-bit
6215 GDB now includes support for overlays; if an executable has been
6216 linked such that multiple sections are based at the same address, GDB
6217 will decide which section to use for symbolic info. You can choose to
6218 control the decision manually, using overlay commands, or implement
6219 additional target-side support and use "overlay load-target" to bring
6220 in the overlay mapping. Do "help overlay" for more detail.
6224 The command "info symbol <address>" displays information about
6225 the symbol at the specified address.
6229 The standard remote protocol now includes an extension that allows
6230 asynchronous collection and display of trace data. This requires
6231 extensive support in the target-side debugging stub. Tracing mode
6232 includes a new interaction mode in GDB and new commands: see the
6233 file tracepoint.c for more details.
6237 Configurations for embedded MIPS now include a simulator contributed
6238 by Cygnus Solutions. The simulator supports the instruction sets
6239 of most MIPS variants.
6243 Sparc configurations may now include the ERC32 simulator contributed
6244 by the European Space Agency. The simulator is not built into
6245 Sparc targets by default; configure with --enable-sim to include it.
6249 For target configurations that may include multiple variants of a
6250 basic architecture (such as MIPS and SH), you may now set the
6251 architecture explicitly. "set arch" sets, "info arch" lists
6252 the possible architectures.
6254 *** Changes in GDB-4.16:
6256 * New native configurations
6258 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6259 M68K NetBSD m68k-*-netbsd*
6260 PowerPC AIX 4.x powerpc-*-aix*
6261 PowerPC MacOS powerpc-*-macos*
6262 PowerPC Windows NT powerpcle-*-cygwin32
6263 RS/6000 AIX 4.x rs6000-*-aix4*
6267 ARM with RDP protocol arm-*-*
6268 I960 with MON960 i960-*-coff
6269 MIPS VxWorks mips*-*-vxworks*
6270 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6271 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6273 Matra Sparclet sparclet-*-*
6277 The powerpc-eabi configuration now includes the PSIM simulator,
6278 contributed by Andrew Cagney, with assistance from Mike Meissner.
6279 PSIM is a very elaborate model of the PowerPC, including not only
6280 basic instruction set execution, but also details of execution unit
6281 performance and I/O hardware. See sim/ppc/README for more details.
6285 GDB now works with Solaris 2.5.
6287 * Windows 95/NT native
6289 GDB will now work as a native debugger on Windows 95 and Windows NT.
6290 To build it from source, you must use the "gnu-win32" environment,
6291 which uses a DLL to emulate enough of Unix to run the GNU tools.
6292 Further information, binaries, and sources are available at
6293 ftp.cygnus.com, under pub/gnu-win32.
6295 * dont-repeat command
6297 If a user-defined command includes the command `dont-repeat', then the
6298 command will not be repeated if the user just types return. This is
6299 useful if the command is time-consuming to run, so that accidental
6300 extra keystrokes don't run the same command many times.
6302 * Send break instead of ^C
6304 The standard remote protocol now includes an option to send a break
6305 rather than a ^C to the target in order to interrupt it. By default,
6306 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6308 * Remote protocol timeout
6310 The standard remote protocol includes a new variable `remotetimeout'
6311 that allows you to set the number of seconds before GDB gives up trying
6312 to read from the target. The default value is 2.
6314 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6316 By default GDB will automatically keep track of objects as they are
6317 loaded and unloaded by the dynamic linker. By using the command `set
6318 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6319 when shared library events occur, thus allowing you to set breakpoints
6320 in shared libraries which are explicitly loaded by the inferior.
6322 Note this feature does not work on hpux8. On hpux9 you must link
6323 /usr/lib/end.o into your program. This feature should work
6324 automatically on hpux10.
6326 * Irix 5.x hardware watchpoint support
6328 Irix 5 configurations now support the use of hardware watchpoints.
6330 * Mips protocol "SYN garbage limit"
6332 When debugging a Mips target using the `target mips' protocol, you
6333 may set the number of characters that GDB will ignore by setting
6334 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6335 every character. The default value is 1050.
6337 * Recording and replaying remote debug sessions
6339 If you set `remotelogfile' to the name of a file, gdb will write to it
6340 a recording of a remote debug session. This recording may then be
6341 replayed back to gdb using "gdbreplay". See gdbserver/README for
6342 details. This is useful when you have a problem with GDB while doing
6343 remote debugging; you can make a recording of the session and send it
6344 to someone else, who can then recreate the problem.
6346 * Speedups for remote debugging
6348 GDB includes speedups for downloading and stepping MIPS systems using
6349 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6350 and more efficient S-record downloading.
6352 * Memory use reductions and statistics collection
6354 GDB now uses less memory and reports statistics about memory usage.
6355 Try the `maint print statistics' command, for example.
6357 *** Changes in GDB-4.15:
6359 * Psymtabs for XCOFF
6361 The symbol reader for AIX GDB now uses partial symbol tables. This
6362 can greatly improve startup time, especially for large executables.
6364 * Remote targets use caching
6366 Remote targets now use a data cache to speed up communication with the
6367 remote side. The data cache could lead to incorrect results because
6368 it doesn't know about volatile variables, thus making it impossible to
6369 debug targets which use memory mapped I/O devices. `set remotecache
6370 off' turns the the data cache off.
6372 * Remote targets may have threads
6374 The standard remote protocol now includes support for multiple threads
6375 in the target system, using new protocol commands 'H' and 'T'. See
6376 gdb/remote.c for details.
6380 If GDB is configured with `--enable-netrom', then it will include
6381 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6382 acts as though it is a bank of ROM on the target board, but you can
6383 write into it over the network. GDB's support consists only of
6384 support for fast loading into the emulated ROM; to debug, you must use
6385 another protocol, such as standard remote protocol. The usual
6386 sequence is something like
6388 target nrom <netrom-hostname>
6390 target remote <netrom-hostname>:1235
6394 GDB now includes support for the Apple Macintosh, as a host only. It
6395 may be run as either an MPW tool or as a standalone application, and
6396 it can debug through the serial port. All the usual GDB commands are
6397 available, but to the target command, you must supply "serial" as the
6398 device type instead of "/dev/ttyXX". See mpw-README in the main
6399 directory for more information on how to build. The MPW configuration
6400 scripts */mpw-config.in support only a few targets, and only the
6401 mips-idt-ecoff target has been tested.
6405 GDB configuration now uses autoconf. This is not user-visible,
6406 but does simplify configuration and building.
6410 GDB now supports hpux10.
6412 *** Changes in GDB-4.14:
6414 * New native configurations
6416 x86 FreeBSD i[345]86-*-freebsd
6417 x86 NetBSD i[345]86-*-netbsd
6418 NS32k NetBSD ns32k-*-netbsd
6419 Sparc NetBSD sparc-*-netbsd
6423 A29K VxWorks a29k-*-vxworks
6424 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6425 CPU32 EST-300 emulator m68*-*-est*
6426 PowerPC ELF powerpc-*-elf
6429 * Alpha OSF/1 support for procfs
6431 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6432 possible to attach to running processes. As the mounting of the /proc
6433 filesystem is optional on the Alpha, GDB automatically determines
6434 the availability of /proc during startup. This can lead to problems
6435 if /proc is unmounted after GDB has been started.
6437 * Arguments to user-defined commands
6439 User commands may accept up to 10 arguments separated by whitespace.
6440 Arguments are accessed within the user command via $arg0..$arg9. A
6443 print $arg0 + $arg1 + $arg2
6445 To execute the command use:
6448 Defines the command "adder" which prints the sum of its three arguments.
6449 Note the arguments are text substitutions, so they may reference variables,
6450 use complex expressions, or even perform inferior function calls.
6452 * New `if' and `while' commands
6454 This makes it possible to write more sophisticated user-defined
6455 commands. Both commands take a single argument, which is the
6456 expression to evaluate, and must be followed by the commands to
6457 execute, one per line, if the expression is nonzero, the list being
6458 terminated by the word `end'. The `if' command list may include an
6459 `else' word, which causes the following commands to be executed only
6460 if the expression is zero.
6462 * Fortran source language mode
6464 GDB now includes partial support for Fortran 77. It will recognize
6465 Fortran programs and can evaluate a subset of Fortran expressions, but
6466 variables and functions may not be handled correctly. GDB will work
6467 with G77, but does not yet know much about symbols emitted by other
6470 * Better HPUX support
6472 Most debugging facilities now work on dynamic executables for HPPAs
6473 running hpux9 or later. You can attach to running dynamically linked
6474 processes, but by default the dynamic libraries will be read-only, so
6475 for instance you won't be able to put breakpoints in them. To change
6476 that behavior do the following before running the program:
6482 This will cause the libraries to be mapped private and read-write.
6483 To revert to the normal behavior, do this:
6489 You cannot set breakpoints or examine data in the library until after
6490 the library is loaded if the function/data symbols do not have
6493 GDB can now also read debug symbols produced by the HP C compiler on
6494 HPPAs (sorry, no C++, Fortran or 68k support).
6496 * Target byte order now dynamically selectable
6498 You can choose which byte order to use with a target system, via the
6499 commands "set endian big" and "set endian little", and you can see the
6500 current setting by using "show endian". You can also give the command
6501 "set endian auto", in which case GDB will use the byte order
6502 associated with the executable. Currently, only embedded MIPS
6503 configurations support dynamic selection of target byte order.
6505 * New DOS host serial code
6507 This version uses DPMI interrupts to handle buffered I/O, so you
6508 no longer need to run asynctsr when debugging boards connected to
6511 *** Changes in GDB-4.13:
6513 * New "complete" command
6515 This lists all the possible completions for the rest of the line, if it
6516 were to be given as a command itself. This is intended for use by emacs.
6518 * Trailing space optional in prompt
6520 "set prompt" no longer adds a space for you after the prompt you set. This
6521 allows you to set a prompt which ends in a space or one that does not.
6523 * Breakpoint hit counts
6525 "info break" now displays a count of the number of times the breakpoint
6526 has been hit. This is especially useful in conjunction with "ignore"; you
6527 can ignore a large number of breakpoint hits, look at the breakpoint info
6528 to see how many times the breakpoint was hit, then run again, ignoring one
6529 less than that number, and this will get you quickly to the last hit of
6532 * Ability to stop printing at NULL character
6534 "set print null-stop" will cause GDB to stop printing the characters of
6535 an array when the first NULL is encountered. This is useful when large
6536 arrays actually contain only short strings.
6538 * Shared library breakpoints
6540 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6541 breakpoints in shared libraries before the executable is run.
6543 * Hardware watchpoints
6545 There is a new hardware breakpoint for the watch command for sparclite
6546 targets. See gdb/sparclite/hw_breakpoint.note.
6548 Hardware watchpoints are also now supported under GNU/Linux.
6552 Annotations have been added. These are for use with graphical interfaces,
6553 and are still experimental. Currently only gdba.el uses these.
6555 * Improved Irix 5 support
6557 GDB now works properly with Irix 5.2.
6559 * Improved HPPA support
6561 GDB now works properly with the latest GCC and GAS.
6563 * New native configurations
6565 Sequent PTX4 i[34]86-sequent-ptx4
6566 HPPA running OSF/1 hppa*-*-osf*
6567 Atari TT running SVR4 m68*-*-sysv4*
6568 RS/6000 LynxOS rs6000-*-lynxos*
6572 OS/9000 i[34]86-*-os9k
6573 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6576 * Hitachi SH7000 and E7000-PC ICE support
6578 There is now support for communicating with the Hitachi E7000-PC ICE.
6579 This is available automatically when GDB is configured for the SH.
6583 As usual, a variety of small fixes and improvements, both generic
6584 and configuration-specific. See the ChangeLog for more detail.
6586 *** Changes in GDB-4.12:
6588 * Irix 5 is now supported
6592 GDB-4.12 on the HPPA has a number of changes which make it unable
6593 to debug the output from the currently released versions of GCC and
6594 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6595 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6596 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6599 *** Changes in GDB-4.11:
6601 * User visible changes:
6605 The "set remotedebug" option is now consistent between the mips remote
6606 target, remote targets using the gdb-specific protocol, UDI (AMD's
6607 debug protocol for the 29k) and the 88k bug monitor. It is now an
6608 integer specifying a debug level (normally 0 or 1, but 2 means more
6609 debugging info for the mips target).
6611 * DEC Alpha native support
6613 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6614 debug info, but GDB works fairly well with the DEC compiler and should
6615 work with a future GCC release. See the README file for a few
6616 Alpha-specific notes.
6618 * Preliminary thread implementation
6620 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6622 * LynxOS native and target support for 386
6624 This release has been hosted on LynxOS 2.2, and also can be configured
6625 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6628 * Improvements in C++ mangling/demangling.
6630 This release has much better g++ debugging, specifically in name
6631 mangling/demangling, virtual function calls, print virtual table,
6632 call methods, ...etc.
6634 *** Changes in GDB-4.10:
6636 * User visible changes:
6638 Remote debugging using the GDB-specific (`target remote') protocol now
6639 supports the `load' command. This is only useful if you have some
6640 other way of getting the stub to the target system, and you can put it
6641 somewhere in memory where it won't get clobbered by the download.
6643 Filename completion now works.
6645 When run under emacs mode, the "info line" command now causes the
6646 arrow to point to the line specified. Also, "info line" prints
6647 addresses in symbolic form (as well as hex).
6649 All vxworks based targets now support a user settable option, called
6650 vxworks-timeout. This option represents the number of seconds gdb
6651 should wait for responses to rpc's. You might want to use this if
6652 your vxworks target is, perhaps, a slow software simulator or happens
6653 to be on the far side of a thin network line.
6657 This release contains support for using a DEC alpha as a GDB host for
6658 cross debugging. Native alpha debugging is not supported yet.
6661 *** Changes in GDB-4.9:
6665 This is the first GDB release which is accompanied by a matching testsuite.
6666 The testsuite requires installation of dejagnu, which should be available
6667 via ftp from most sites that carry GNU software.
6671 'Cfront' style demangling has had its name changed to 'ARM' style, to
6672 emphasize that it was written from the specifications in the C++ Annotated
6673 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6674 disclaimers, it still generated too much confusion with users attempting to
6675 use gdb with AT&T cfront.
6679 GDB now uses a standard remote interface to a simulator library.
6680 So far, the library contains simulators for the Zilog Z8001/2, the
6681 Hitachi H8/300, H8/500 and Super-H.
6683 * New targets supported
6685 H8/300 simulator h8300-hitachi-hms or h8300hms
6686 H8/500 simulator h8500-hitachi-hms or h8500hms
6687 SH simulator sh-hitachi-hms or sh
6688 Z8000 simulator z8k-zilog-none or z8ksim
6689 IDT MIPS board over serial line mips-idt-ecoff
6691 Cross-debugging to GO32 targets is supported. It requires a custom
6692 version of the i386-stub.c module which is integrated with the
6693 GO32 memory extender.
6695 * New remote protocols
6697 MIPS remote debugging protocol.
6699 * New source languages supported
6701 This version includes preliminary support for Chill, a Pascal like language
6702 used by telecommunications companies. Chill support is also being integrated
6703 into the GNU compiler, but we don't know when it will be publically available.
6706 *** Changes in GDB-4.8:
6708 * HP Precision Architecture supported
6710 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6711 version of this support was available as a set of patches from the
6712 University of Utah. GDB does not support debugging of programs
6713 compiled with the HP compiler, because HP will not document their file
6714 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6715 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6717 Many problems in the preliminary version have been fixed.
6719 * Faster and better demangling
6721 We have improved template demangling and fixed numerous bugs in the GNU style
6722 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6723 character types (wchar_t) are now supported. Demangling of each symbol is now
6724 only done once, and is cached when the symbol table for a file is read in.
6725 This results in a small increase in memory usage for C programs, a moderate
6726 increase in memory usage for C++ programs, and a fantastic speedup in
6729 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6730 from the specifications in the Annotated Reference Manual, which AT&T's
6731 compiler does not actually implement.
6733 * G++ multiple inheritance compiler problem
6735 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6736 inheritance lattices was reworked to properly discover ambiguities. We
6737 recently found an example which causes this new algorithm to fail in a
6738 very subtle way, producing bad debug information for those classes.
6739 The file 'gcc.patch' (in this directory) can be applied to gcc to
6740 circumvent the problem. A future GCC release will contain a complete
6743 The previous G++ debug info problem (mentioned below for the gdb-4.7
6744 release) is fixed in gcc version 2.3.2.
6746 * Improved configure script
6748 The `configure' script will now attempt to guess your system type if
6749 you don't supply a host system type. The old scheme of supplying a
6750 host system triplet is preferable over using this. All the magic is
6751 done in the new `config.guess' script. Examine it for details.
6753 We have also brought our configure script much more in line with the FSF's
6754 version. It now supports the --with-xxx options. In particular,
6755 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6756 The resulting GDB will not be able to read arbitrary object file formats --
6757 only the format ``expected'' to be used on the configured target system.
6758 We hope to make this the default in a future release.
6760 * Documentation improvements
6762 There's new internal documentation on how to modify GDB, and how to
6763 produce clean changes to the code. We implore people to read it
6764 before submitting changes.
6766 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6767 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6768 `info' files are also provided. To build `info' files from scratch,
6769 you will need the latest `makeinfo' release, which will be available in
6770 a future texinfo-X.Y release.
6772 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6773 We're not sure exactly which versions have this problem, but it has
6774 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6775 or better. If that isn't possible, there is a patch in
6776 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6777 around this problem.
6781 GDB now supports array constants that can be used in expressions typed in by
6782 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6783 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6786 The new directory `gdb/sparclite' contains a program that demonstrates
6787 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6789 * New native hosts supported
6791 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6792 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6794 * New targets supported
6796 AMD 29k family via UDI a29k-amd-udi or udi29k
6798 * New file formats supported
6800 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6801 HPUX core files, and SCO 3.2v2 core files.
6805 Attaching to processes now works again; thanks for the many bug reports.
6807 We have also stomped on a bunch of core dumps caused by
6808 printf_filtered("%s") problems.
6810 We eliminated a copyright problem on the rpc and ptrace header files
6811 for VxWorks, which was discovered at the last minute during the 4.7
6812 release. You should now be able to build a VxWorks GDB.
6814 You can now interrupt gdb while an attached process is running. This
6815 will cause the attached process to stop, and give control back to GDB.
6817 We fixed problems caused by using too many file descriptors
6818 for reading symbols from object files and libraries. This was
6819 especially a problem for programs that used many (~100) shared
6822 The `step' command now only enters a subroutine if there is line number
6823 information for the subroutine. Otherwise it acts like the `next'
6824 command. Previously, `step' would enter subroutines if there was
6825 any debugging information about the routine. This avoids problems
6826 when using `cc -g1' on MIPS machines.
6828 * Internal improvements
6830 GDB's internal interfaces have been improved to make it easier to support
6831 debugging of multiple languages in the future.
6833 GDB now uses a common structure for symbol information internally.
6834 Minimal symbols (derived from linkage symbols in object files), partial
6835 symbols (from a quick scan of debug information), and full symbols
6836 contain a common subset of information, making it easier to write
6837 shared code that handles any of them.
6839 * New command line options
6841 We now accept --silent as an alias for --quiet.
6845 The memory-mapped-malloc library is now licensed under the GNU Library
6846 General Public License.
6848 *** Changes in GDB-4.7:
6850 * Host/native/target split
6852 GDB has had some major internal surgery to untangle the support for
6853 hosts and remote targets. Now, when you configure GDB for a remote
6854 target, it will no longer load in all of the support for debugging
6855 local programs on the host. When fully completed and tested, this will
6856 ensure that arbitrary host/target combinations are possible.
6858 The primary conceptual shift is to separate the non-portable code in
6859 GDB into three categories. Host specific code is required any time GDB
6860 is compiled on that host, regardless of the target. Target specific
6861 code relates to the peculiarities of the target, but can be compiled on
6862 any host. Native specific code is everything else: it can only be
6863 built when the host and target are the same system. Child process
6864 handling and core file support are two common `native' examples.
6866 GDB's use of /proc for controlling Unix child processes is now cleaner.
6867 It has been split out into a single module under the `target_ops' vector,
6868 plus two native-dependent functions for each system that uses /proc.
6870 * New hosts supported
6872 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6873 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6874 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6876 * New targets supported
6878 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6879 68030 and CPU32 m68030-*-*, m68332-*-*
6881 * New native hosts supported
6883 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6884 (386bsd is not well tested yet)
6885 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6887 * New file formats supported
6889 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6890 supports reading of `a.out.adobe' object files, which are an a.out
6891 format extended with minimal information about multiple sections.
6895 `show copying' is the same as the old `info copying'.
6896 `show warranty' is the same as `info warrantee'.
6897 These were renamed for consistency. The old commands continue to work.
6899 `info handle' is a new alias for `info signals'.
6901 You can now define pre-command hooks, which attach arbitrary command
6902 scripts to any command. The commands in the hook will be executed
6903 prior to the user's command. You can also create a hook which will be
6904 executed whenever the program stops. See gdb.texinfo.
6908 We now deal with Cfront style name mangling, and can even extract type
6909 info from mangled symbols. GDB can automatically figure out which
6910 symbol mangling style your C++ compiler uses.
6912 Calling of methods and virtual functions has been improved as well.
6916 The crash that occured when debugging Sun Ansi-C compiled binaries is
6917 fixed. This was due to mishandling of the extra N_SO stabs output
6920 We also finally got Ultrix 4.2 running in house, and fixed core file
6921 support, with help from a dozen people on the net.
6923 John M. Farrell discovered that the reason that single-stepping was so
6924 slow on all of the Mips based platforms (primarily SGI and DEC) was
6925 that we were trying to demangle and lookup a symbol used for internal
6926 purposes on every instruction that was being stepped through. Changing
6927 the name of that symbol so that it couldn't be mistaken for a C++
6928 mangled symbol sped things up a great deal.
6930 Rich Pixley sped up symbol lookups in general by getting much smarter
6931 about when C++ symbol mangling is necessary. This should make symbol
6932 completion (TAB on the command line) much faster. It's not as fast as
6933 we'd like, but it's significantly faster than gdb-4.6.
6937 A new user controllable variable 'call_scratch_address' can
6938 specify the location of a scratch area to be used when GDB
6939 calls a function in the target. This is necessary because the
6940 usual method of putting the scratch area on the stack does not work
6941 in systems that have separate instruction and data spaces.
6943 We integrated changes to support the 29k UDI (Universal Debugger
6944 Interface), but discovered at the last minute that we didn't have all
6945 of the appropriate copyright paperwork. We are working with AMD to
6946 resolve this, and hope to have it available soon.
6950 We have sped up the remote serial line protocol, especially for targets
6951 with lots of registers. It now supports a new `expedited status' ('T')
6952 message which can be used in place of the existing 'S' status message.
6953 This allows the remote stub to send only the registers that GDB
6954 needs to make a quick decision about single-stepping or conditional
6955 breakpoints, eliminating the need to fetch the entire register set for
6956 each instruction being stepped through.
6958 The GDB remote serial protocol now implements a write-through cache for
6959 registers, only re-reading the registers if the target has run.
6961 There is also a new remote serial stub for SPARC processors. You can
6962 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6963 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6964 processor with a serial port.
6968 Configure.in files have become much easier to read and modify. A new
6969 `table driven' format makes it more obvious what configurations are
6970 supported, and what files each one uses.
6974 There is a new opcodes library which will eventually contain all of the
6975 disassembly routines and opcode tables. At present, it only contains
6976 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6977 disassembler (binutils/objdump) to share these routines.
6979 The libiberty library is now copylefted under the GNU Library General
6980 Public License. This allows more liberal use, and was done so libg++
6981 can use it. This makes no difference to GDB, since the Library License
6982 grants all the rights from the General Public License.
6986 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6987 reference to the stabs symbol info used by the debugger. It is (as far
6988 as we know) the only published document on this fascinating topic. We
6989 encourage you to read it, compare it to the stabs information on your
6990 system, and send improvements on the document in general (to
6991 bug-gdb@prep.ai.mit.edu).
6993 And, of course, many bugs have been fixed.
6996 *** Changes in GDB-4.6:
6998 * Better support for C++ function names
7000 GDB now accepts as input the "demangled form" of C++ overloaded function
7001 names and member function names, and can do command completion on such names
7002 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7003 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7004 Make use of command completion, it is your friend.
7006 GDB also now accepts a variety of C++ mangled symbol formats. They are
7007 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7008 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7009 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7010 for the list of formats.
7012 * G++ symbol mangling problem
7014 Recent versions of gcc have a bug in how they emit debugging information for
7015 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7016 directory) can be applied to gcc to fix the problem. Alternatively, if you
7017 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7018 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7019 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7022 * New 'maintenance' command
7024 All of the commands related to hacking GDB internals have been moved out of
7025 the main command set, and now live behind the 'maintenance' command. This
7026 can also be abbreviated as 'mt'. The following changes were made:
7028 dump-me -> maintenance dump-me
7029 info all-breakpoints -> maintenance info breakpoints
7030 printmsyms -> maintenance print msyms
7031 printobjfiles -> maintenance print objfiles
7032 printpsyms -> maintenance print psymbols
7033 printsyms -> maintenance print symbols
7035 The following commands are new:
7037 maintenance demangle Call internal GDB demangler routine to
7038 demangle a C++ link name and prints the result.
7039 maintenance print type Print a type chain for a given symbol
7041 * Change to .gdbinit file processing
7043 We now read the $HOME/.gdbinit file before processing the argv arguments
7044 (e.g. reading symbol files or core files). This allows global parameters to
7045 be set, which will apply during the symbol reading. The ./.gdbinit is still
7046 read after argv processing.
7048 * New hosts supported
7050 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7052 GNU/Linux support i386-unknown-linux or linux
7054 We are also including code to support the HP/PA running BSD and HPUX. This
7055 is almost guaranteed not to work, as we didn't have time to test or build it
7056 for this release. We are including it so that the more adventurous (or
7057 masochistic) of you can play with it. We also had major problems with the
7058 fact that the compiler that we got from HP doesn't support the -g option.
7061 * New targets supported
7063 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7065 * More smarts about finding #include files
7067 GDB now remembers the compilation directory for all include files, and for
7068 all files from which C is generated (like yacc and lex sources). This
7069 greatly improves GDB's ability to find yacc/lex sources, and include files,
7070 especially if you are debugging your program from a directory different from
7071 the one that contains your sources.
7073 We also fixed a bug which caused difficulty with listing and setting
7074 breakpoints in include files which contain C code. (In the past, you had to
7075 try twice in order to list an include file that you hadn't looked at before.)
7077 * Interesting infernals change
7079 GDB now deals with arbitrary numbers of sections, where the symbols for each
7080 section must be relocated relative to that section's landing place in the
7081 target's address space. This work was needed to support ELF with embedded
7082 stabs used by Solaris-2.0.
7084 * Bug fixes (of course!)
7086 There have been loads of fixes for the following things:
7087 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7088 i960, stabs, DOS(GO32), procfs, etc...
7090 See the ChangeLog for details.
7092 *** Changes in GDB-4.5:
7094 * New machines supported (host and target)
7096 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7098 SGI Irix-4.x mips-sgi-irix4 or iris4
7100 * New malloc package
7102 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7103 Mmalloc is capable of handling mutiple heaps of memory. It is also
7104 capable of saving a heap to a file, and then mapping it back in later.
7105 This can be used to greatly speedup the startup of GDB by using a
7106 pre-parsed symbol table which lives in a mmalloc managed heap. For
7107 more details, please read mmalloc/mmalloc.texi.
7111 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7112 'help info proc' for details.
7114 * MIPS ecoff symbol table format
7116 The code that reads MIPS symbol table format is now supported on all hosts.
7117 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7120 * File name changes for MS-DOS
7122 Many files in the config directories have been renamed to make it easier to
7123 support GDB on MS-DOSe systems (which have very restrictive file name
7124 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7125 environment) is close to working but has some remaining problems. Note
7126 that debugging of DOS programs is not supported, due to limitations
7127 in the ``operating system'', but it can be used to host cross-debugging.
7129 * Cross byte order fixes
7131 Many fixes have been made to support cross debugging of Sparc and MIPS
7132 targets from hosts whose byte order differs.
7134 * New -mapped and -readnow options
7136 If memory-mapped files are available on your system through the 'mmap'
7137 system call, you can use the -mapped option on the `file' or
7138 `symbol-file' commands to cause GDB to write the symbols from your
7139 program into a reusable file. If the program you are debugging is
7140 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7141 Future GDB debugging sessions will notice the presence of this file,
7142 and will quickly map in symbol information from it, rather than reading
7143 the symbol table from the executable program. Using the '-mapped'
7144 option in a GDB `file' or `symbol-file' command has the same effect as
7145 starting GDB with the '-mapped' command-line option.
7147 You can cause GDB to read the entire symbol table immediately by using
7148 the '-readnow' option with any of the commands that load symbol table
7149 information (or on the GDB command line). This makes the command
7150 slower, but makes future operations faster.
7152 The -mapped and -readnow options are typically combined in order to
7153 build a `fred.syms' file that contains complete symbol information.
7154 A simple GDB invocation to do nothing but build a `.syms' file for future
7157 gdb -batch -nx -mapped -readnow programname
7159 The `.syms' file is specific to the host machine on which GDB is run.
7160 It holds an exact image of GDB's internal symbol table. It cannot be
7161 shared across multiple host platforms.
7163 * longjmp() handling
7165 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7166 siglongjmp() without losing control. This feature has not yet been ported to
7167 all systems. It currently works on many 386 platforms, all MIPS-based
7168 platforms (SGI, DECstation, etc), and Sun3/4.
7172 Preliminary work has been put in to support the new Solaris OS from Sun. At
7173 this time, it can control and debug processes, but it is not capable of
7178 As always, many many bug fixes. The major areas were with g++, and mipsread.
7179 People using the MIPS-based platforms should experience fewer mysterious
7180 crashes and trashed symbol tables.
7182 *** Changes in GDB-4.4:
7184 * New machines supported (host and target)
7186 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7188 BSD Reno on Vax vax-dec-bsd
7189 Ultrix on Vax vax-dec-ultrix
7191 * New machines supported (target)
7193 AMD 29000 embedded, using EBMON a29k-none-none
7197 GDB continues to improve its handling of C++. `References' work better.
7198 The demangler has also been improved, and now deals with symbols mangled as
7199 per the Annotated C++ Reference Guide.
7201 GDB also now handles `stabs' symbol information embedded in MIPS
7202 `ecoff' symbol tables. Since the ecoff format was not easily
7203 extensible to handle new languages such as C++, this appeared to be a
7204 good way to put C++ debugging info into MIPS binaries. This option
7205 will be supported in the GNU C compiler, version 2, when it is
7208 * New features for SVR4
7210 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7211 shared libraries. Debugging dynamically linked programs should present
7212 only minor differences from debugging statically linked programs.
7214 The `info proc' command will print out information about any process
7215 on an SVR4 system (including the one you are debugging). At the moment,
7216 it prints the address mappings of the process.
7218 If you bring up GDB on another SVR4 system, please send mail to
7219 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7221 * Better dynamic linking support in SunOS
7223 Reading symbols from shared libraries which contain debugging symbols
7224 now works properly. However, there remain issues such as automatic
7225 skipping of `transfer vector' code during function calls, which
7226 make it harder to debug code in a shared library, than to debug the
7227 same code linked statically.
7231 GDB is now using the latest `getopt' routines from the FSF. This
7232 version accepts the -- prefix for options with long names. GDB will
7233 continue to accept the old forms (-option and +option) as well.
7234 Various single letter abbreviations for options have been explicity
7235 added to the option table so that they won't get overshadowed in the
7236 future by other options that begin with the same letter.
7240 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7241 Many assorted bugs have been handled. Many more remain to be handled.
7242 See the various ChangeLog files (primarily in gdb and bfd) for details.
7245 *** Changes in GDB-4.3:
7247 * New machines supported (host and target)
7249 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7250 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7251 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7253 * Almost SCO Unix support
7255 We had hoped to support:
7256 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7257 (except for core file support), but we discovered very late in the release
7258 that it has problems with process groups that render gdb unusable. Sorry
7259 about that. I encourage people to fix it and post the fixes.
7261 * Preliminary ELF and DWARF support
7263 GDB can read ELF object files on System V Release 4, and can handle
7264 debugging records for C, in DWARF format, in ELF files. This support
7265 is preliminary. If you bring up GDB on another SVR4 system, please
7266 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7271 GDB now uses the latest `readline' library. One user-visible change
7272 is that two tabs will list possible command completions, which previously
7273 required typing M-? (meta-question mark, or ESC ?).
7277 The `stepi' bug that many of you noticed has been squashed.
7278 Many bugs in C++ have been handled. Many more remain to be handled.
7279 See the various ChangeLog files (primarily in gdb and bfd) for details.
7281 * State of the MIPS world (in case you wondered):
7283 GDB can understand the symbol tables emitted by the compilers
7284 supplied by most vendors of MIPS-based machines, including DEC. These
7285 symbol tables are in a format that essentially nobody else uses.
7287 Some versions of gcc come with an assembler post-processor called
7288 mips-tfile. This program is required if you want to do source-level
7289 debugging of gcc-compiled programs. I believe FSF does not ship
7290 mips-tfile with gcc version 1, but it will eventually come with gcc
7293 Debugging of g++ output remains a problem. g++ version 1.xx does not
7294 really support it at all. (If you're lucky, you should be able to get
7295 line numbers and stack traces to work, but no parameters or local
7296 variables.) With some work it should be possible to improve the
7299 When gcc version 2 is released, you will have somewhat better luck.
7300 However, even then you will get confusing results for inheritance and
7303 We will eventually provide full debugging of g++ output on
7304 DECstations. This will probably involve some kind of stabs-in-ecoff
7305 encapulation, but the details have not been worked out yet.
7308 *** Changes in GDB-4.2:
7310 * Improved configuration
7312 Only one copy of `configure' exists now, and it is not self-modifying.
7313 Porting BFD is simpler.
7317 The `step' and `next' commands now only stop at the first instruction
7318 of a source line. This prevents the multiple stops that used to occur
7319 in switch statements, for-loops, etc. `Step' continues to stop if a
7320 function that has debugging information is called within the line.
7324 Lots of small bugs fixed. More remain.
7326 * New host supported (not target)
7328 Intel 386 PC clone running Mach i386-none-mach
7331 *** Changes in GDB-4.1:
7333 * Multiple source language support
7335 GDB now has internal scaffolding to handle several source languages.
7336 It determines the type of each source file from its filename extension,
7337 and will switch expression parsing and number formatting to match the
7338 language of the function in the currently selected stack frame.
7339 You can also specifically set the language to be used, with
7340 `set language c' or `set language modula-2'.
7344 GDB now has preliminary support for the GNU Modula-2 compiler,
7345 currently under development at the State University of New York at
7346 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7347 continue through the fall of 1991 and into 1992.
7349 Other Modula-2 compilers are currently not supported, and attempting to
7350 debug programs compiled with them will likely result in an error as the
7351 symbol table is read. Feel free to work on it, though!
7353 There are hooks in GDB for strict type checking and range checking,
7354 in the `Modula-2 philosophy', but they do not currently work.
7358 GDB can now write to executable and core files (e.g. patch
7359 a variable's value). You must turn this switch on, specify
7360 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7361 by assigning a new value to a variable. Modifications take
7364 * Automatic SunOS shared library reading
7366 When you run your program, GDB automatically determines where its
7367 shared libraries (if any) have been loaded, and reads their symbols.
7368 The `share' command is no longer needed. This also works when
7369 examining core files.
7373 You can specify the number of lines that the `list' command shows.
7376 * New machines supported (host and target)
7378 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7379 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7380 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7382 * New hosts supported (not targets)
7384 IBM RT/PC: romp-ibm-aix or rtpc
7386 * New targets supported (not hosts)
7388 AMD 29000 embedded with COFF a29k-none-coff
7389 AMD 29000 embedded with a.out a29k-none-aout
7390 Ultracomputer remote kernel debug a29k-nyu-kern
7392 * New remote interfaces
7398 *** Changes in GDB-4.0:
7402 Wide output is wrapped at good places to make the output more readable.
7404 Gdb now supports cross-debugging from a host machine of one type to a
7405 target machine of another type. Communication with the target system
7406 is over serial lines. The ``target'' command handles connecting to the
7407 remote system; the ``load'' command will download a program into the
7408 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7409 also supports debugging of realtime processes running under VxWorks,
7410 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7411 stub on the target system.
7413 New CPUs supported include the AMD 29000 and Intel 960.
7415 GDB now reads object files and symbol tables via a ``binary file''
7416 library, which allows a single copy of GDB to debug programs of multiple
7417 object file types such as a.out and coff.
7419 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7420 refcard.dvi and refcard.ps are available to format it).
7423 * Control-Variable user interface simplified
7425 All variables that control the operation of the debugger can be set
7426 by the ``set'' command, and displayed by the ``show'' command.
7428 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7429 ``Show prompt'' produces the response:
7430 Gdb's prompt is new-gdb=>.
7432 What follows are the NEW set commands. The command ``help set'' will
7433 print a complete list of old and new set commands. ``help set FOO''
7434 will give a longer description of the variable FOO. ``show'' will show
7435 all of the variable descriptions and their current settings.
7437 confirm on/off: Enables warning questions for operations that are
7438 hard to recover from, e.g. rerunning the program while
7439 it is already running. Default is ON.
7441 editing on/off: Enables EMACS style command line editing
7442 of input. Previous lines can be recalled with
7443 control-P, the current line can be edited with control-B,
7444 you can search for commands with control-R, etc.
7447 history filename NAME: NAME is where the gdb command history
7448 will be stored. The default is .gdb_history,
7449 or the value of the environment variable
7452 history size N: The size, in commands, of the command history. The
7453 default is 256, or the value of the environment variable
7456 history save on/off: If this value is set to ON, the history file will
7457 be saved after exiting gdb. If set to OFF, the
7458 file will not be saved. The default is OFF.
7460 history expansion on/off: If this value is set to ON, then csh-like
7461 history expansion will be performed on
7462 command line input. The default is OFF.
7464 radix N: Sets the default radix for input and output. It can be set
7465 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7466 in the current radix, so "set radix 10" is always a no-op.
7468 height N: This integer value is the number of lines on a page. Default
7469 is 24, the current `stty rows'' setting, or the ``li#''
7470 setting from the termcap entry matching the environment
7473 width N: This integer value is the number of characters on a line.
7474 Default is 80, the current `stty cols'' setting, or the ``co#''
7475 setting from the termcap entry matching the environment
7478 Note: ``set screensize'' is obsolete. Use ``set height'' and
7479 ``set width'' instead.
7481 print address on/off: Print memory addresses in various command displays,
7482 such as stack traces and structure values. Gdb looks
7483 more ``symbolic'' if you turn this off; it looks more
7484 ``machine level'' with it on. Default is ON.
7486 print array on/off: Prettyprint arrays. New convenient format! Default
7489 print demangle on/off: Print C++ symbols in "source" form if on,
7492 print asm-demangle on/off: Same, for assembler level printouts
7495 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7498 * Support for Epoch Environment.
7500 The epoch environment is a version of Emacs v18 with windowing. One
7501 new command, ``inspect'', is identical to ``print'', except that if you
7502 are running in the epoch environment, the value is printed in its own
7506 * Support for Shared Libraries
7508 GDB can now debug programs and core files that use SunOS shared libraries.
7509 Symbols from a shared library cannot be referenced
7510 before the shared library has been linked with the program (this
7511 happens after you type ``run'' and before the function main() is entered).
7512 At any time after this linking (including when examining core files
7513 from dynamically linked programs), gdb reads the symbols from each
7514 shared library when you type the ``sharedlibrary'' command.
7515 It can be abbreviated ``share''.
7517 sharedlibrary REGEXP: Load shared object library symbols for files
7518 matching a unix regular expression. No argument
7519 indicates to load symbols for all shared libraries.
7521 info sharedlibrary: Status of loaded shared libraries.
7526 A watchpoint stops execution of a program whenever the value of an
7527 expression changes. Checking for this slows down execution
7528 tremendously whenever you are in the scope of the expression, but is
7529 quite useful for catching tough ``bit-spreader'' or pointer misuse
7530 problems. Some machines such as the 386 have hardware for doing this
7531 more quickly, and future versions of gdb will use this hardware.
7533 watch EXP: Set a watchpoint (breakpoint) for an expression.
7535 info watchpoints: Information about your watchpoints.
7537 delete N: Deletes watchpoint number N (same as breakpoints).
7538 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7539 enable N: Re-enables watchpoint number N (same as breakpoints).
7542 * C++ multiple inheritance
7544 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7547 * C++ exception handling
7549 Gdb now supports limited C++ exception handling. Besides the existing
7550 ability to breakpoint on an exception handler, gdb can breakpoint on
7551 the raising of an exception (before the stack is peeled back to the
7554 catch FOO: If there is a FOO exception handler in the dynamic scope,
7555 set a breakpoint to catch exceptions which may be raised there.
7556 Multiple exceptions (``catch foo bar baz'') may be caught.
7558 info catch: Lists all exceptions which may be caught in the
7559 current stack frame.
7562 * Minor command changes
7564 The command ``call func (arg, arg, ...)'' now acts like the print
7565 command, except it does not print or save a value if the function's result
7566 is void. This is similar to dbx usage.
7568 The ``up'' and ``down'' commands now always print the frame they end up
7569 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7570 frames without printing.
7572 * New directory command
7574 'dir' now adds directories to the FRONT of the source search path.
7575 The path starts off empty. Source files that contain debug information
7576 about the directory in which they were compiled can be found even
7577 with an empty path; Sun CC and GCC include this information. If GDB can't
7578 find your source file in the current directory, type "dir .".
7580 * Configuring GDB for compilation
7582 For normal use, type ``./configure host''. See README or gdb.texinfo
7585 GDB now handles cross debugging. If you are remotely debugging between
7586 two different machines, type ``./configure host -target=targ''.
7587 Host is the machine where GDB will run; targ is the machine
7588 where the program that you are debugging will run.