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 (PAC) on AArch64 Linux. Return
20 addresses that required unmasking are shown in the backtrace with the
23 * Two new convenience functions $_cimag and $_creal that extract the
24 imaginary and real parts respectively from complex numbers.
26 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
27 provide the exitcode or exit status of the shell commands launched by
28 GDB commands such as "shell", "pipe" and "make".
32 ** The gdb.Value type has a new method 'format_string' which returns a
33 string representing the value. The formatting is controlled by the
34 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
35 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
36 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
38 ** gdb.Type has a new property 'objfile' which returns the objfile the
41 ** The frame information printed by the python frame filtering code
42 is now consistent with what the 'backtrace' command prints when
43 there are no filters, or when the 'backtrace' '-no-filters' option
46 ** The new function gdb.lookup_static_symbol can be used to look up
47 symbols with static linkage.
49 ** gdb.Objfile has new methods 'lookup_global_symbol' and
50 'lookup_static_symbol' to lookup a symbol from this objfile only.
52 ** gdb.Block now supports the dictionary syntax for accessing symbols in
53 this block (e.g. block['local_variable']).
57 | [COMMAND] | SHELL_COMMAND
58 | -d DELIM COMMAND DELIM SHELL_COMMAND
59 pipe [COMMAND] | SHELL_COMMAND
60 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
61 Executes COMMAND and sends its output to SHELL_COMMAND.
62 With no COMMAND, repeat the last executed command
63 and send its output to SHELL_COMMAND.
65 with SETTING [VALUE] [-- COMMAND]
66 w SETTING [VALUE] [-- COMMAND]
67 Temporarily set SETTING, run COMMAND, and restore SETTING.
68 Usage: with SETTING -- COMMAND
69 With no COMMAND, repeats the last executed command.
70 SETTING is any GDB setting you can change with the "set"
71 subcommands. For example, 'with language c -- print someobj'
72 temporarily switches to the C language in order to print someobj.
73 Settings can be combined: 'w lang c -- w print elements unlimited --
74 usercmd' switches to the C language and runs usercmd with no limit
75 of array elements to print.
77 maint with SETTING [VALUE] [-- COMMAND]
78 Like "with", but works with "maintenance set" settings.
80 set may-call-functions [on|off]
81 show may-call-functions
82 This controls whether GDB will attempt to call functions in
83 the program, such as with expressions in the print command. It
84 defaults to on. Calling functions in the program being debugged
85 can have undesired side effects. It is now possible to forbid
86 such function calls. If function calls are forbidden, GDB will throw
87 an error when a command (such as print expression) calls a function
90 set print finish [on|off]
92 This controls whether the `finish' command will display the value
93 that is returned by the current function. When `off', the value is
94 still entered into the value history, but it is not printed. The
99 Allows deeply nested structures to be simplified when printing by
100 replacing deeply nested parts (beyond the max-depth) with ellipses.
101 The default max-depth is 20, but this can be set to unlimited to get
102 the old behavior back.
104 set logging debugredirect [on|off]
105 By default, GDB debug output will go to both the terminal and the logfile.
106 Set if you want debug output to go only to the log file.
108 set style title foreground COLOR
109 set style title background COLOR
110 set style title intensity VALUE
111 Control the styling of titles.
113 set style highlight foreground COLOR
114 set style highlight background COLOR
115 set style highlight intensity VALUE
116 Control the styling of highlightings.
118 maint set test-settings KIND
119 maint show test-settings KIND
120 A set of commands used by the testsuite for exercising the settings
123 set print frame-info [short-location|location|location-and-address
124 |source-and-location|source-line|auto]
125 show print frame-info
126 This controls what frame information is printed by the commands printing
127 a frame. This setting will e.g. influence the behaviour of 'backtrace',
128 'frame', 'stepi'. The python frame filtering also respect this setting.
129 The 'backtrace' '-frame-info' option can override this global setting.
134 The "help" command uses the title style to enhance the
135 readibility of its output by styling the classes and
139 Similarly to "help", the "apropos" command also uses the
140 title style for the command names. "apropos" accepts now
141 a flag "-v" (verbose) to show the full documentation
142 of matching commands and to use the highlight style to mark
143 the documentation parts matching REGEXP.
147 The GDB printf and eval commands can now print C-style and Ada-style
148 string convenience variables without calling functions in the program.
149 This allows to do formatted printing of strings without having
150 a running inferior, or when debugging a core dump.
152 info sources [-dirname | -basename] [--] [REGEXP]
153 This command has now optional arguments to only print the files
154 whose names match REGEXP. The arguments -dirname and -basename
155 allow to restrict matching respectively to the dirname and basename
159 The "show style" and its subcommands are now styling
160 a style name in their output using its own style, to help
161 the user visualize the different styles.
163 set print frame-arguments
164 The new value 'presence' indicates to only indicate the presence of
165 arguments using ..., instead of printing argument names and values.
167 set print raw-frame-arguments
168 show print raw-frame-arguments
170 These commands replace the similarly-named "set/show print raw
171 frame-arguments" commands (now with a dash instead of a space). The
172 old commands are now deprecated and may be removed in a future
175 maint test-options require-delimiter
176 maint test-options unknown-is-error
177 maint test-options unknown-is-operand
178 maint show test-options-completion-result
179 Commands used by the testsuite to validate the command options
182 * New command options, command completion
184 GDB now has a standard infrastructure to support dash-style command
185 options ('-OPT'). One benefit is that commands that use it can
186 easily support completion of command line arguments. Try "CMD
187 -[TAB]" or "help CMD" to find options supported by a command. Over
188 time, we intend to migrate most commands to this infrastructure. A
189 number of commands got support for new command options in this
192 ** The "print" and "compile print" commands now support a number of
193 options that allow overriding relevant global print settings as
194 set by "set print" subcommands:
198 -array-indexes [on|off]
199 -elements NUMBER|unlimited
203 -repeats NUMBER|unlimited
204 -static-members [on|off]
209 Note that because the "print"/"compile print" commands accept
210 arbitrary expressions which may look like options (including
211 abbreviations), if you specify any command option, then you must
212 use a double dash ("--") to mark the end of argument processing.
214 ** The "backtrace" command now supports a number of options that
215 allow overriding relevant global print settings as set by "set
216 backtrace" and "set print" subcommands:
218 -entry-values no|only|preferred|if-needed|both|compact|default
219 -frame-arguments all|scalars|none
220 -raw-frame-arguments [on|off]
221 -frame-info auto|source-line|location|source-and-location
222 |location-and-address|short-location
226 In addition, the full/no-filters/hide qualifiers are now also
227 exposed as command options too:
233 ** The "frame apply", "tfaas" and "faas" commands similarly now
234 support the following options:
239 ** The new "info sources" options -dirname and -basename options
240 are using the standard '-OPT' infrastructure.
242 All options above can also be abbreviated. The argument of boolean
243 (on/off) options can be 0/1 too, and also the argument is assumed
244 "on" if omitted. This allows writing compact command invocations,
247 (gdb) p -r -p -o 0 -- *myptr
249 The above is equivalent to:
251 (gdb) print -raw -pretty -object off -- *myptr
253 ** The "info types" command now supports the '-q' flag to disable
254 printing of some header information in a similar fashion to "info
255 variables" and "info functions".
257 * Completion improvements
259 ** GDB can now complete the options of the "thread apply all" and
260 "taas" commands, and their "-ascending" option can now be
263 ** GDB can now complete the options of the "info threads", "info
264 functions", "info variables", "info locals", and "info args"
267 ** GDB can now complete the options of the "compile file" and
268 "compile code" commands. The "compile file" command now
269 completes on filenames.
271 ** GDB can now complete the backtrace command's
272 "full/no-filters/hide" qualifiers.
274 * In settings, you can now abbreviate "unlimited".
276 E.g., "set print elements u" is now equivalent to "set print
282 This lists all the possible completions for the rest of the line, if it
283 were to be given as a command itself. This is intended for use by MI
284 frontends in cases when separate CLI and MI channels cannot be used.
286 -catch-throw, -catch-rethrow, and -catch-catch
287 These can be used to catch C++ exceptions in a similar fashion to
288 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
292 The testsuite now creates the files gdb.cmd (containing the arguments
293 used to launch GDB) and gdb.in (containing all the commands sent to
294 GDB) in the output directory for each test script. Multiple invocations
295 are appended with .1, .2, .3 etc.
297 * Building GDB and GDBserver now requires GNU make >= 3.82.
299 Using another implementation of the make program or an earlier version of
300 GNU make to build GDB or GDBserver is not supported.
302 *** Changes in GDB 8.3
304 * GDB and GDBserver now support access to additional registers on
305 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
308 * GDB now has experimental support for the compilation and injection of
309 C++ source code into the inferior. This beta release does not include
310 support for several language features, such as templates, constructors,
313 This feature requires GCC 7.1 or higher built with libcp1.so
316 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
317 can be passed using the '[ADDRESS]:PORT' notation, or the regular
318 'ADDRESS:PORT' method.
320 * DWARF index cache: GDB can now automatically save indices of DWARF
321 symbols on disk to speed up further loading of the same binaries.
323 * Ada task switching is now supported on aarch64-elf targets when
324 debugging a program using the Ravenscar Profile. For more information,
325 see the "Tasking Support when using the Ravenscar Profile" section
326 in the GDB user manual.
328 * GDB in batch mode now exits with status 1 if the last command to be
331 * The RISC-V target now supports target descriptions.
333 * System call catchpoints now support system call aliases on FreeBSD.
334 When the ABI of a system call changes in FreeBSD, this is
335 implemented by leaving a compatibility system call using the old ABI
336 at the existing number and allocating a new system call number for
337 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
338 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
339 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
340 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
341 so that a system call catchpoint for the 'kevent' system call will
342 catch invocations of both the 'kevent' and 'freebsd11_kevent'
343 binaries. This ensures that 'kevent' system calls are caught for
344 binaries using either the old or new ABIs.
346 * Terminal styling is now available for the CLI and the TUI. GNU
347 Source Highlight can additionally be used to provide styling of
348 source code snippets. See the "set style" commands, below, for more
351 * Removed support for old demangling styles arm, edg, gnu, hp and
356 set debug compile-cplus-types
357 show debug compile-cplus-types
358 Control the display of debug output about type conversion in the
359 C++ compile feature. Commands have no effect while compiliong
364 Control whether debug output about files/functions skipping is
367 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
368 Apply a command to some frames.
369 FLAG arguments allow to control what output to produce and how to handle
370 errors raised when applying COMMAND to a frame.
373 Apply a command to all threads (ignoring errors and empty output).
374 Shortcut for 'thread apply all -s COMMAND'.
377 Apply a command to all frames (ignoring errors and empty output).
378 Shortcut for 'frame apply all -s COMMAND'.
381 Apply a command to all frames of all threads (ignoring errors and empty
383 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
385 maint set dwarf unwinders (on|off)
386 maint show dwarf unwinders
387 Control whether DWARF unwinders can be used.
390 Display a list of open files for a process.
394 Changes to the "frame", "select-frame", and "info frame" CLI commands.
395 These commands all now take a frame specification which
396 is either a frame level, or one of the keywords 'level', 'address',
397 'function', or 'view' followed by a parameter. Selecting a frame by
398 address, or viewing a frame outside the current backtrace now
399 requires the use of a keyword. Selecting a frame by level is
400 unchanged. The MI comment "-stack-select-frame" is unchanged.
402 target remote FILENAME
403 target extended-remote FILENAME
404 If FILENAME is a Unix domain socket, GDB will attempt to connect
405 to this socket instead of opening FILENAME as a character device.
407 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
408 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
409 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
410 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
411 These commands can now print only the searched entities
412 matching the provided regexp(s), giving a condition
413 on the entity names or entity types. The flag -q disables
414 printing headers or informations messages.
420 These commands now determine the syntax for the shown entities
421 according to the language chosen by `set language'. In particular,
422 `set language auto' means to automatically choose the language of
425 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
426 The 'thread apply' command accepts new FLAG arguments.
427 FLAG arguments allow to control what output to produce and how to handle
428 errors raised when applying COMMAND to a thread.
430 set tui tab-width NCHARS
431 show tui tab-width NCHARS
432 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
434 set style enabled [on|off]
436 Enable or disable terminal styling. Styling is enabled by default
437 on most hosts, but disabled by default when in batch mode.
439 set style sources [on|off]
441 Enable or disable source code styling. Source code styling is
442 enabled by default, but only takes effect if styling in general is
443 enabled, and if GDB was linked with GNU Source Highlight.
445 set style filename foreground COLOR
446 set style filename background COLOR
447 set style filename intensity VALUE
448 Control the styling of file names.
450 set style function foreground COLOR
451 set style function background COLOR
452 set style function intensity VALUE
453 Control the styling of function names.
455 set style variable foreground COLOR
456 set style variable background COLOR
457 set style variable intensity VALUE
458 Control the styling of variable names.
460 set style address foreground COLOR
461 set style address background COLOR
462 set style address intensity VALUE
463 Control the styling of addresses.
467 ** The default version of the MI interpreter is now 3 (-i=mi3).
469 ** The '-data-disassemble' MI command now accepts an '-a' option to
470 disassemble the whole function surrounding the given program
471 counter value or function name. Support for this feature can be
472 verified by using the "-list-features" command, which should
473 contain "data-disassemble-a-option".
475 ** Command responses and notifications that include a frame now include
476 the frame's architecture in a new "arch" attribute.
478 ** The output of information about multi-location breakpoints (which is
479 syntactically incorrect in MI 2) has changed in MI 3. This affects
480 the following commands and events:
484 - =breakpoint-created
485 - =breakpoint-modified
487 The -fix-multi-location-breakpoint-output command can be used to enable
488 this behavior with previous MI versions.
490 * New native configurations
492 GNU/Linux/RISC-V riscv*-*-linux*
493 FreeBSD/riscv riscv*-*-freebsd*
497 GNU/Linux/RISC-V riscv*-*-linux*
499 CSKY GNU/LINUX csky*-*-linux
500 FreeBSD/riscv riscv*-*-freebsd*
502 GNU/Linux/OpenRISC or1k*-*-linux*
506 GDB no longer supports native debugging on versions of MS-Windows
511 ** GDB no longer supports Python versions less than 2.6.
513 ** The gdb.Inferior type has a new 'progspace' property, which is the program
514 space associated to that inferior.
516 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
517 of objfiles associated to that program space.
519 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
520 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
523 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
524 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
525 correct and did not work properly.
527 ** The gdb.Value type has a new constructor, which is used to construct a
528 gdb.Value from a Python buffer object and a gdb.Type.
534 Enable or disable the undefined behavior sanitizer. This is
535 disabled by default, but passing --enable-ubsan=yes or
536 --enable-ubsan=auto to configure will enable it. Enabling this can
537 cause a performance penalty. The undefined behavior sanitizer was
538 first introduced in GCC 4.9.
540 *** Changes in GDB 8.2
542 * The 'set disassembler-options' command now supports specifying options
545 * The 'symbol-file' command now accepts an '-o' option to add a relative
546 offset to all sections.
548 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
549 a relative offset to all sections, but it allows to override the load
550 address of individual sections using '-s'.
552 * The 'add-symbol-file' command no longer requires the second argument
553 (address of the text section).
555 * The endianness used with the 'set endian auto' mode in the absence of
556 an executable selected for debugging is now the last endianness chosen
557 either by one of the 'set endian big' and 'set endian little' commands
558 or by inferring from the last executable used, rather than the startup
561 * The pager now allows a "c" response, meaning to disable the pager
562 for the rest of the current command.
564 * The commands 'info variables/functions/types' now show the source line
565 numbers of symbol definitions when available.
567 * 'info proc' now works on running processes on FreeBSD systems and core
568 files created on FreeBSD systems.
570 * C expressions can now use _Alignof, and C++ expressions can now use
573 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
574 the vector length while the process is running.
580 Control display of debugging info regarding the FreeBSD native target.
582 set|show varsize-limit
583 This new setting allows the user to control the maximum size of Ada
584 objects being printed when those objects have a variable type,
585 instead of that maximum size being hardcoded to 65536 bytes.
587 set|show record btrace cpu
588 Controls the processor to be used for enabling errata workarounds for
591 maint check libthread-db
592 Run integrity checks on the current inferior's thread debugging
595 maint set check-libthread-db (on|off)
596 maint show check-libthread-db
597 Control whether to run integrity checks on inferior specific thread
598 debugging libraries as they are loaded. The default is not to
603 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
605 ** The commands attached to a breakpoint can be set by assigning to
606 the breakpoint's "commands" field.
608 ** gdb.execute can now execute multi-line gdb commands.
610 ** The new functions gdb.convenience_variable and
611 gdb.set_convenience_variable can be used to get and set the value
612 of convenience variables.
614 ** A gdb.Parameter will no longer print the "set" help text on an
615 ordinary "set"; instead by default a "set" will be silent unless
616 the get_set_string method returns a non-empty string.
620 RiscV ELF riscv*-*-elf
622 * Removed targets and native configurations
624 m88k running OpenBSD m88*-*-openbsd*
625 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
626 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
627 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
629 * Aarch64/Linux hardware watchpoints improvements
631 Hardware watchpoints on unaligned addresses are now properly
632 supported when running Linux kernel 4.10 or higher: read and access
633 watchpoints are no longer spuriously missed, and all watchpoints
634 lengths between 1 and 8 bytes are supported. On older kernels,
635 watchpoints set on unaligned addresses are no longer missed, with
636 the tradeoff that there is a possibility of false hits being
641 --enable-codesign=CERT
642 This can be used to invoke "codesign -s CERT" after building gdb.
643 This option is useful on macOS, where code signing is required for
644 gdb to work properly.
646 --disable-gdbcli has been removed
647 This is now silently accepted, but does nothing.
649 *** Changes in GDB 8.1
651 * GDB now supports dynamically creating arbitrary register groups specified
652 in XML target descriptions. This allows for finer grain grouping of
653 registers on systems with a large amount of registers.
655 * The 'ptype' command now accepts a '/o' flag, which prints the
656 offsets and sizes of fields in a struct, like the pahole(1) tool.
658 * New "--readnever" command line option instructs GDB to not read each
659 symbol file's symbolic debug information. This makes startup faster
660 but at the expense of not being able to perform symbolic debugging.
661 This option is intended for use cases where symbolic debugging will
662 not be used, e.g., when you only need to dump the debuggee's core.
664 * GDB now uses the GNU MPFR library, if available, to emulate target
665 floating-point arithmetic during expression evaluation when the target
666 uses different floating-point formats than the host. At least version
667 3.1 of GNU MPFR is required.
669 * GDB now supports access to the guarded-storage-control registers and the
670 software-based guarded-storage broadcast control registers on IBM z14.
672 * On Unix systems, GDB now supports transmitting environment variables
673 that are to be set or unset to GDBserver. These variables will
674 affect the environment to be passed to the remote inferior.
676 To inform GDB of environment variables that are to be transmitted to
677 GDBserver, use the "set environment" command. Only user set
678 environment variables are sent to GDBserver.
680 To inform GDB of environment variables that are to be unset before
681 the remote inferior is started by the GDBserver, use the "unset
682 environment" command.
684 * Completion improvements
686 ** GDB can now complete function parameters in linespecs and
687 explicit locations without quoting. When setting breakpoints,
688 quoting around functions names to help with TAB-completion is
689 generally no longer necessary. For example, this now completes
692 (gdb) b function(in[TAB]
693 (gdb) b function(int)
695 Related, GDB is no longer confused with completing functions in
696 C++ anonymous namespaces:
699 (gdb) b (anonymous namespace)::[TAB][TAB]
700 (anonymous namespace)::a_function()
701 (anonymous namespace)::b_function()
703 ** GDB now has much improved linespec and explicit locations TAB
704 completion support, that better understands what you're
705 completing and offers better suggestions. For example, GDB no
706 longer offers data symbols as possible completions when you're
707 setting a breakpoint.
709 ** GDB now TAB-completes label symbol names.
711 ** The "complete" command now mimics TAB completion accurately.
713 * New command line options (gcore)
716 Dump all memory mappings.
718 * Breakpoints on C++ functions are now set on all scopes by default
720 By default, breakpoints on functions/methods are now interpreted as
721 specifying all functions with the given name ignoring missing
722 leading scopes (namespaces and classes).
724 For example, assuming a C++ program with symbols named:
729 both commands "break func()" and "break B::func()" set a breakpoint
732 You can use the new flag "-qualified" to override this. This makes
733 GDB interpret the specified function name as a complete
734 fully-qualified name instead. For example, using the same C++
735 program, the "break -q B::func" command sets a breakpoint on
736 "B::func", only. A parameter has been added to the Python
737 gdb.Breakpoint constructor to achieve the same result when creating
738 a breakpoint from Python.
740 * Breakpoints on functions marked with C++ ABI tags
742 GDB can now set breakpoints on functions marked with C++ ABI tags
743 (e.g., [abi:cxx11]). See here for a description of ABI tags:
744 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
746 Functions with a C++11 abi tag are demangled/displayed like this:
748 function[abi:cxx11](int)
751 You can now set a breakpoint on such functions simply as if they had
754 (gdb) b function(int)
756 Or if you need to disambiguate between tags, like:
758 (gdb) b function[abi:other_tag](int)
760 Tab completion was adjusted accordingly as well.
764 ** New events gdb.new_inferior, gdb.inferior_deleted, and
765 gdb.new_thread are emitted. See the manual for further
766 description of these.
768 ** A new function, "gdb.rbreak" has been added to the Python API.
769 This function allows the setting of a large number of breakpoints
770 via a regex pattern in Python. See the manual for further details.
772 ** Python breakpoints can now accept explicit locations. See the
773 manual for a further description of this feature.
776 * New features in the GDB remote stub, GDBserver
778 ** GDBserver is now able to start inferior processes with a
779 specified initial working directory.
781 The user can set the desired working directory to be used from
782 GDB using the new "set cwd" command.
784 ** New "--selftest" command line option runs some GDBserver self
785 tests. These self tests are disabled in releases.
787 ** On Unix systems, GDBserver now does globbing expansion and variable
788 substitution in inferior command line arguments.
790 This is done by starting inferiors using a shell, like GDB does.
791 See "set startup-with-shell" in the user manual for how to disable
792 this from GDB when using "target extended-remote". When using
793 "target remote", you can disable the startup with shell by using the
794 new "--no-startup-with-shell" GDBserver command line option.
796 ** On Unix systems, GDBserver now supports receiving environment
797 variables that are to be set or unset from GDB. These variables
798 will affect the environment to be passed to the inferior.
800 * When catching an Ada exception raised with a message, GDB now prints
801 the message in the catchpoint hit notification. In GDB/MI mode, that
802 information is provided as an extra field named "exception-message"
803 in the *stopped notification.
805 * Trait objects can now be inspected When debugging Rust code. This
806 requires compiler support which will appear in Rust 1.24.
810 QEnvironmentHexEncoded
811 Inform GDBserver of an environment variable that is to be passed to
812 the inferior when starting it.
815 Inform GDBserver of an environment variable that is to be unset
816 before starting the remote inferior.
819 Inform GDBserver that the environment should be reset (i.e.,
820 user-set environment variables should be unset).
823 Indicates whether the inferior must be started with a shell or not.
826 Tell GDBserver that the inferior to be started should use a specific
829 * The "maintenance print c-tdesc" command now takes an optional
830 argument which is the file name of XML target description.
832 * The "maintenance selftest" command now takes an optional argument to
833 filter the tests to be run.
835 * The "enable", and "disable" commands now accept a range of
836 breakpoint locations, e.g. "enable 1.3-5".
841 Set and show the current working directory for the inferior.
844 Set and show compilation command used for compiling and injecting code
845 with the 'compile' commands.
847 set debug separate-debug-file
848 show debug separate-debug-file
849 Control the display of debug output about separate debug file search.
851 set dump-excluded-mappings
852 show dump-excluded-mappings
853 Control whether mappings marked with the VM_DONTDUMP flag should be
854 dumped when generating a core file.
857 List the registered selftests.
860 Start the debugged program stopping at the first instruction.
863 Control display of debugging messages related to OpenRISC targets.
865 set|show print type nested-type-limit
866 Set and show the limit of nesting level for nested types that the
867 type printer will show.
869 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
872 * Safer/improved support for debugging with no debug info
874 GDB no longer assumes functions with no debug information return
877 This means that GDB now refuses to call such functions unless you
878 tell it the function's type, by either casting the call to the
879 declared return type, or by casting the function to a function
880 pointer of the right type, and calling that:
882 (gdb) p getenv ("PATH")
883 'getenv' has unknown return type; cast the call to its declared return type
884 (gdb) p (char *) getenv ("PATH")
885 $1 = 0x7fffffffe "/usr/local/bin:/"...
886 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
887 $2 = 0x7fffffffe "/usr/local/bin:/"...
889 Similarly, GDB no longer assumes that global variables with no debug
890 info have type 'int', and refuses to print the variable's value
891 unless you tell it the variable's type:
894 'var' has unknown type; cast it to its declared type
898 * New native configurations
900 FreeBSD/aarch64 aarch64*-*-freebsd*
901 FreeBSD/arm arm*-*-freebsd*
905 FreeBSD/aarch64 aarch64*-*-freebsd*
906 FreeBSD/arm arm*-*-freebsd*
907 OpenRISC ELF or1k*-*-elf
909 * Removed targets and native configurations
911 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
913 *** Changes in GDB 8.0
915 * GDB now supports access to the PKU register on GNU/Linux. The register is
916 added by the Memory Protection Keys for Userspace feature which will be
917 available in future Intel CPUs.
919 * GDB now supports C++11 rvalue references.
923 ** New functions to start, stop and access a running btrace recording.
924 ** Rvalue references are now supported in gdb.Type.
926 * GDB now supports recording and replaying rdrand and rdseed Intel 64
929 * Building GDB and GDBserver now requires a C++11 compiler.
931 For example, GCC 4.8 or later.
933 It is no longer possible to build GDB or GDBserver with a C
934 compiler. The --disable-build-with-cxx configure option has been
937 * Building GDB and GDBserver now requires GNU make >= 3.81.
939 It is no longer supported to build GDB or GDBserver with another
940 implementation of the make program or an earlier version of GNU make.
942 * Native debugging on MS-Windows supports command-line redirection
944 Command-line arguments used for starting programs on MS-Windows can
945 now include redirection symbols supported by native Windows shells,
946 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
947 as "run", "start", and "set args", as well as the corresponding MI
950 * Support for thread names on MS-Windows.
952 GDB now catches and handles the special exception that programs
953 running on MS-Windows use to assign names to threads in the
956 * Support for Java programs compiled with gcj has been removed.
958 * User commands now accept an unlimited number of arguments.
959 Previously, only up to 10 was accepted.
961 * The "eval" command now expands user-defined command arguments.
963 This makes it easier to process a variable number of arguments:
968 eval "print $arg%d", $i
973 * Target descriptions can now describe registers for sparc32 and sparc64.
975 * GDB now supports DWARF version 5 (debug information format).
976 Its .debug_names index is not yet supported.
978 * New native configurations
980 FreeBSD/mips mips*-*-freebsd
984 Synopsys ARC arc*-*-elf32
985 FreeBSD/mips mips*-*-freebsd
987 * Removed targets and native configurations
989 Alpha running FreeBSD alpha*-*-freebsd*
990 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
995 Erases all the flash memory regions reported by the target.
997 maint print arc arc-instruction address
998 Print internal disassembler information about instruction at a given address.
1002 set disassembler-options
1003 show disassembler-options
1004 Controls the passing of target specific information to the disassembler.
1005 If it is necessary to specify more than one disassembler option then
1006 multiple options can be placed together into a comma separated list.
1007 The default value is the empty string. Currently, the only supported
1008 targets are ARM, PowerPC and S/390.
1013 Erases all the flash memory regions reported by the target. This is
1014 equivalent to the CLI command flash-erase.
1016 -file-list-shared-libraries
1017 List the shared libraries in the program. This is
1018 equivalent to the CLI command "info shared".
1021 Catchpoints stopping the program when Ada exceptions are
1022 handled. This is equivalent to the CLI command "catch handlers".
1024 *** Changes in GDB 7.12
1026 * GDB and GDBserver now build with a C++ compiler by default.
1028 The --enable-build-with-cxx configure option is now enabled by
1029 default. One must now explicitly configure with
1030 --disable-build-with-cxx in order to build with a C compiler. This
1031 option will be removed in a future release.
1033 * GDBserver now supports recording btrace without maintaining an active
1036 * GDB now supports a negative repeat count in the 'x' command to examine
1037 memory backward from the given address. For example:
1040 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1041 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1042 (gdb) x/-5i 0x0000000000400580
1043 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1044 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1045 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1046 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1047 0x40057b <main(int, char**)+25>:
1048 callq 0x400536 <Func1(int, char const*)>
1050 * Fortran: Support structures with fields of dynamic types and
1051 arrays of dynamic types.
1053 * The symbol dumping maintenance commands have new syntax.
1054 maint print symbols [-pc address] [--] [filename]
1055 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1056 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1057 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1058 maint print msymbols [-objfile objfile] [--] [filename]
1060 * GDB now supports multibit bitfields and enums in target register
1063 * New Python-based convenience function $_as_string(val), which returns
1064 the textual representation of a value. This function is especially
1065 useful to obtain the text label of an enum value.
1067 * Intel MPX bound violation handling.
1069 Segmentation faults caused by a Intel MPX boundary violation
1070 now display the kind of violation (upper or lower), the memory
1071 address accessed and the memory bounds, along with the usual
1072 signal received and code location.
1076 Program received signal SIGSEGV, Segmentation fault
1077 Upper bound violation while accessing address 0x7fffffffc3b3
1078 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1079 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1081 * Rust language support.
1082 GDB now supports debugging programs written in the Rust programming
1083 language. See https://www.rust-lang.org/ for more information about
1086 * Support for running interpreters on specified input/output devices
1088 GDB now supports a new mechanism that allows frontends to provide
1089 fully featured GDB console views, as a better alternative to
1090 building such views on top of the "-interpreter-exec console"
1091 command. See the new "new-ui" command below. With that command,
1092 frontends can now start GDB in the traditional command-line mode
1093 running in an embedded terminal emulator widget, and create a
1094 separate MI interpreter running on a specified i/o device. In this
1095 way, GDB handles line editing, history, tab completion, etc. in the
1096 console all by itself, and the GUI uses the separate MI interpreter
1097 for its own control and synchronization, invisible to the command
1100 * The "catch syscall" command catches groups of related syscalls.
1102 The "catch syscall" command now supports catching a group of related
1103 syscalls using the 'group:' or 'g:' prefix.
1108 skip -gfile file-glob-pattern
1109 skip -function function
1110 skip -rfunction regular-expression
1111 A generalized form of the skip command, with new support for
1112 glob-style file names and regular expressions for function names.
1113 Additionally, a file spec and a function spec may now be combined.
1115 maint info line-table REGEXP
1116 Display the contents of GDB's internal line table data struture.
1119 Run any GDB unit tests that were compiled in.
1122 Start a new user interface instance running INTERP as interpreter,
1123 using the TTY file for input/output.
1127 ** gdb.Breakpoint objects have a new attribute "pending", which
1128 indicates whether the breakpoint is pending.
1129 ** Three new breakpoint-related events have been added:
1130 gdb.breakpoint_created, gdb.breakpoint_modified, and
1131 gdb.breakpoint_deleted.
1133 signal-event EVENTID
1134 Signal ("set") the given MS-Windows event object. This is used in
1135 conjunction with the Windows JIT debugging (AeDebug) support, where
1136 the OS suspends a crashing process until a debugger can attach to
1137 it. Resuming the crashing process, in order to debug it, is done by
1138 signalling an event.
1140 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1141 was added in GDBserver, including JIT compiling fast tracepoint's
1142 conditional expression bytecode into native code.
1144 * Support for various remote target protocols and ROM monitors has
1147 target m32rsdi Remote M32R debugging over SDI
1148 target mips MIPS remote debugging protocol
1149 target pmon PMON ROM monitor
1150 target ddb NEC's DDB variant of PMON for Vr4300
1151 target rockhopper NEC RockHopper variant of PMON
1152 target lsi LSI variant of PMO
1154 * Support for tracepoints and fast tracepoints on powerpc-linux,
1155 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1156 including JIT compiling fast tracepoint's conditional expression
1157 bytecode into native code.
1159 * MI async record =record-started now includes the method and format used for
1160 recording. For example:
1162 =record-started,thread-group="i1",method="btrace",format="bts"
1164 * MI async record =thread-selected now includes the frame field. For example:
1166 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1170 Andes NDS32 nds32*-*-elf
1172 *** Changes in GDB 7.11
1174 * GDB now supports debugging kernel-based threads on FreeBSD.
1176 * Per-inferior thread numbers
1178 Thread numbers are now per inferior instead of global. If you're
1179 debugging multiple inferiors, GDB displays thread IDs using a
1180 qualified INF_NUM.THR_NUM form. For example:
1184 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1185 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1186 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1187 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1189 As consequence, thread numbers as visible in the $_thread
1190 convenience variable and in Python's InferiorThread.num attribute
1191 are no longer unique between inferiors.
1193 GDB now maintains a second thread ID per thread, referred to as the
1194 global thread ID, which is the new equivalent of thread numbers in
1195 previous releases. See also $_gthread below.
1197 For backwards compatibility, MI's thread IDs always refer to global
1200 * Commands that accept thread IDs now accept the qualified
1201 INF_NUM.THR_NUM form as well. For example:
1204 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1207 * In commands that accept a list of thread IDs, you can now refer to
1208 all threads of an inferior using a star wildcard. GDB accepts
1209 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1210 refer to all threads of the current inferior. For example, "info
1213 * You can use "info threads -gid" to display the global thread ID of
1216 * The new convenience variable $_gthread holds the global number of
1219 * The new convenience variable $_inferior holds the number of the
1222 * GDB now displays the ID and name of the thread that hit a breakpoint
1223 or received a signal, if your program is multi-threaded. For
1226 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1227 Thread 1 "main" received signal SIGINT, Interrupt.
1229 * Record btrace now supports non-stop mode.
1231 * Support for tracepoints on aarch64-linux was added in GDBserver.
1233 * The 'record instruction-history' command now indicates speculative execution
1234 when using the Intel Processor Trace recording format.
1236 * GDB now allows users to specify explicit locations, bypassing
1237 the linespec parser. This feature is also available to GDB/MI
1240 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1241 GDB now is able to debug both AArch64 applications and ARM applications
1244 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1245 including JIT compiling fast tracepoint's conditional expression bytecode
1248 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1250 * "info threads", "info inferiors", "info display", "info checkpoints"
1251 and "maint info program-spaces" now list the corresponding items in
1252 ascending ID order, for consistency with all other "info" commands.
1254 * In Ada, the overloads selection menu has been enhanced to display the
1255 parameter types and the return types for the matching overloaded subprograms.
1259 maint set target-non-stop (on|off|auto)
1260 maint show target-non-stop
1261 Control whether GDB targets always operate in non-stop mode even if
1262 "set non-stop" is "off". The default is "auto", meaning non-stop
1263 mode is enabled if supported by the target.
1265 maint set bfd-sharing
1266 maint show bfd-sharing
1267 Control the reuse of bfd objects.
1270 show debug bfd-cache
1271 Control display of debugging info regarding bfd caching.
1275 Control display of debugging info regarding FreeBSD threads.
1277 set remote multiprocess-extensions-packet
1278 show remote multiprocess-extensions-packet
1279 Set/show the use of the remote protocol multiprocess extensions.
1281 set remote thread-events
1282 show remote thread-events
1283 Set/show the use of thread create/exit events.
1285 set ada print-signatures on|off
1286 show ada print-signatures"
1287 Control whether parameter types and return types are displayed in overloads
1288 selection menus. It is activaled (@code{on}) by default.
1292 Controls the maximum size of memory, in bytes, that GDB will
1293 allocate for value contents. Prevents incorrect programs from
1294 causing GDB to allocate overly large buffers. Default is 64k.
1296 * The "disassemble" command accepts a new modifier: /s.
1297 It prints mixed source+disassembly like /m with two differences:
1298 - disassembled instructions are now printed in program order, and
1299 - and source for all relevant files is now printed.
1300 The "/m" option is now considered deprecated: its "source-centric"
1301 output hasn't proved useful in practice.
1303 * The "record instruction-history" command accepts a new modifier: /s.
1304 It behaves exactly like /m and prints mixed source+disassembly.
1306 * The "set scheduler-locking" command supports a new mode "replay".
1307 It behaves like "off" in record mode and like "on" in replay mode.
1309 * Support for various ROM monitors has been removed:
1311 target dbug dBUG ROM monitor for Motorola ColdFire
1312 target picobug Motorola picobug monitor
1313 target dink32 DINK32 ROM monitor for PowerPC
1314 target m32r Renesas M32R/D ROM monitor
1315 target mon2000 mon2000 ROM monitor
1316 target ppcbug PPCBUG ROM monitor for PowerPC
1318 * Support for reading/writing memory and extracting values on architectures
1319 whose memory is addressable in units of any integral multiple of 8 bits.
1322 Allows to break when an Ada exception is handled.
1324 * New remote packets
1327 Indicates that an exec system call was executed.
1329 exec-events feature in qSupported
1330 The qSupported packet allows GDB to request support for exec
1331 events using the new 'gdbfeature' exec-event, and the qSupported
1332 response can contain the corresponding 'stubfeature'. Set and
1333 show commands can be used to display whether these features are enabled.
1336 Equivalent to interrupting with the ^C character, but works in
1339 thread created stop reason (T05 create:...)
1340 Indicates that the thread was just created and is stopped at entry.
1342 thread exit stop reply (w exitcode;tid)
1343 Indicates that the thread has terminated.
1346 Enables/disables thread create and exit event reporting. For
1347 example, this is used in non-stop mode when GDB stops a set of
1348 threads and synchronously waits for the their corresponding stop
1349 replies. Without exit events, if one of the threads exits, GDB
1350 would hang forever not knowing that it should no longer expect a
1351 stop for that same thread.
1354 Indicates that there are no resumed threads left in the target (all
1355 threads are stopped). The remote stub reports support for this stop
1356 reply to GDB's qSupported query.
1359 Enables/disables catching syscalls from the inferior process.
1360 The remote stub reports support for this packet to GDB's qSupported query.
1362 syscall_entry stop reason
1363 Indicates that a syscall was just called.
1365 syscall_return stop reason
1366 Indicates that a syscall just returned.
1368 * Extended-remote exec events
1370 ** GDB now has support for exec events on extended-remote Linux targets.
1371 For such targets with Linux kernels 2.5.46 and later, this enables
1372 follow-exec-mode and exec catchpoints.
1374 set remote exec-event-feature-packet
1375 show remote exec-event-feature-packet
1376 Set/show the use of the remote exec event feature.
1378 * Thread names in remote protocol
1380 The reply to qXfer:threads:read may now include a name attribute for each
1383 * Target remote mode fork and exec events
1385 ** GDB now has support for fork and exec events on target remote mode
1386 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1387 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1388 fork and exec catchpoints.
1390 * Remote syscall events
1392 ** GDB now has support for catch syscall on remote Linux targets,
1393 currently enabled on x86/x86_64 architectures.
1395 set remote catch-syscall-packet
1396 show remote catch-syscall-packet
1397 Set/show the use of the remote catch syscall feature.
1401 ** The -var-set-format command now accepts the zero-hexadecimal
1402 format. It outputs data in hexadecimal format with zero-padding on the
1407 ** gdb.InferiorThread objects have a new attribute "global_num",
1408 which refers to the thread's global thread ID. The existing
1409 "num" attribute now refers to the thread's per-inferior number.
1410 See "Per-inferior thread numbers" above.
1411 ** gdb.InferiorThread objects have a new attribute "inferior", which
1412 is the Inferior object the thread belongs to.
1414 *** Changes in GDB 7.10
1416 * Support for process record-replay and reverse debugging on aarch64*-linux*
1417 targets has been added. GDB now supports recording of A64 instruction set
1418 including advance SIMD instructions.
1420 * Support for Sun's version of the "stabs" debug file format has been removed.
1422 * GDB now honors the content of the file /proc/PID/coredump_filter
1423 (PID is the process ID) on GNU/Linux systems. This file can be used
1424 to specify the types of memory mappings that will be included in a
1425 corefile. For more information, please refer to the manual page of
1426 "core(5)". GDB also has a new command: "set use-coredump-filter
1427 on|off". It allows to set whether GDB will read the content of the
1428 /proc/PID/coredump_filter file when generating a corefile.
1430 * The "info os" command on GNU/Linux can now display information on
1432 "info os cpus" Listing of all cpus/cores on the system
1434 * GDB has two new commands: "set serial parity odd|even|none" and
1435 "show serial parity". These allows to set or show parity for the
1438 * The "info source" command now displays the producer string if it was
1439 present in the debug info. This typically includes the compiler version
1440 and may include things like its command line arguments.
1442 * The "info dll", an alias of the "info sharedlibrary" command,
1443 is now available on all platforms.
1445 * Directory names supplied to the "set sysroot" commands may be
1446 prefixed with "target:" to tell GDB to access shared libraries from
1447 the target system, be it local or remote. This replaces the prefix
1448 "remote:". The default sysroot has been changed from "" to
1449 "target:". "remote:" is automatically converted to "target:" for
1450 backward compatibility.
1452 * The system root specified by "set sysroot" will be prepended to the
1453 filename of the main executable (if reported to GDB as absolute by
1454 the operating system) when starting processes remotely, and when
1455 attaching to already-running local or remote processes.
1457 * GDB now supports automatic location and retrieval of executable
1458 files from remote targets. Remote debugging can now be initiated
1459 using only a "target remote" or "target extended-remote" command
1460 (no "set sysroot" or "file" commands are required). See "New remote
1463 * The "dump" command now supports verilog hex format.
1465 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1467 * On GNU/Linux, GDB and gdbserver are now able to access executable
1468 and shared library files without a "set sysroot" command when
1469 attaching to processes running in different mount namespaces from
1470 the debugger. This makes it possible to attach to processes in
1471 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1472 See "New remote packets" below.
1474 * The "tui reg" command now provides completion for all of the
1475 available register groups, including target specific groups.
1477 * The HISTSIZE environment variable is no longer read when determining
1478 the size of GDB's command history. GDB now instead reads the dedicated
1479 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1480 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1485 ** Memory ports can now be unbuffered.
1489 ** gdb.Objfile objects have a new attribute "username",
1490 which is the name of the objfile as specified by the user,
1491 without, for example, resolving symlinks.
1492 ** You can now write frame unwinders in Python.
1493 ** gdb.Type objects have a new method "optimized_out",
1494 returning optimized out gdb.Value instance of this type.
1495 ** gdb.Value objects have new methods "reference_value" and
1496 "const_value" which return a reference to the value and a
1497 "const" version of the value respectively.
1501 maint print symbol-cache
1502 Print the contents of the symbol cache.
1504 maint print symbol-cache-statistics
1505 Print statistics of symbol cache usage.
1507 maint flush-symbol-cache
1508 Flush the contents of the symbol cache.
1512 Start branch trace recording using Branch Trace Store (BTS) format.
1515 Evaluate expression by using the compiler and print result.
1519 Explicit commands for enabling and disabling tui mode.
1522 set mpx bound on i386 and amd64
1523 Support for bound table investigation on Intel MPX enabled applications.
1527 Start branch trace recording using Intel Processor Trace format.
1530 Print information about branch tracing internals.
1532 maint btrace packet-history
1533 Print the raw branch tracing data.
1535 maint btrace clear-packet-history
1536 Discard the stored raw branch tracing data.
1539 Discard all branch tracing data. It will be fetched and processed
1540 anew by the next "record" command.
1545 Renamed from "set debug dwarf2-die".
1546 show debug dwarf-die
1547 Renamed from "show debug dwarf2-die".
1549 set debug dwarf-read
1550 Renamed from "set debug dwarf2-read".
1551 show debug dwarf-read
1552 Renamed from "show debug dwarf2-read".
1554 maint set dwarf always-disassemble
1555 Renamed from "maint set dwarf2 always-disassemble".
1556 maint show dwarf always-disassemble
1557 Renamed from "maint show dwarf2 always-disassemble".
1559 maint set dwarf max-cache-age
1560 Renamed from "maint set dwarf2 max-cache-age".
1561 maint show dwarf max-cache-age
1562 Renamed from "maint show dwarf2 max-cache-age".
1564 set debug dwarf-line
1565 show debug dwarf-line
1566 Control display of debugging info regarding DWARF line processing.
1569 show max-completions
1570 Set the maximum number of candidates to be considered during
1571 completion. The default value is 200. This limit allows GDB
1572 to avoid generating large completion lists, the computation of
1573 which can cause the debugger to become temporarily unresponsive.
1575 set history remove-duplicates
1576 show history remove-duplicates
1577 Control the removal of duplicate history entries.
1579 maint set symbol-cache-size
1580 maint show symbol-cache-size
1581 Control the size of the symbol cache.
1583 set|show record btrace bts buffer-size
1584 Set and show the size of the ring buffer used for branch tracing in
1586 The obtained size may differ from the requested size. Use "info
1587 record" to see the obtained buffer size.
1589 set debug linux-namespaces
1590 show debug linux-namespaces
1591 Control display of debugging info regarding Linux namespaces.
1593 set|show record btrace pt buffer-size
1594 Set and show the size of the ring buffer used for branch tracing in
1595 Intel Processor Trace format.
1596 The obtained size may differ from the requested size. Use "info
1597 record" to see the obtained buffer size.
1599 maint set|show btrace pt skip-pad
1600 Set and show whether PAD packets are skipped when computing the
1603 * The command 'thread apply all' can now support new option '-ascending'
1604 to call its specified command for all threads in ascending order.
1606 * Python/Guile scripting
1608 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1609 special section named `.debug_gdb_scripts'.
1611 * New remote packets
1613 qXfer:btrace-conf:read
1614 Return the branch trace configuration for the current thread.
1616 Qbtrace-conf:bts:size
1617 Set the requested ring buffer size for branch tracing in BTS format.
1620 Enable Intel Procesor Trace-based branch tracing for the current
1621 process. The remote stub reports support for this packet to GDB's
1624 Qbtrace-conf:pt:size
1625 Set the requested ring buffer size for branch tracing in Intel Processor
1629 Indicates a memory breakpoint instruction was executed, irrespective
1630 of whether it was GDB that planted the breakpoint or the breakpoint
1631 is hardcoded in the program. This is required for correct non-stop
1635 Indicates the target stopped for a hardware breakpoint. This is
1636 required for correct non-stop mode operation.
1639 Return information about files on the remote system.
1641 qXfer:exec-file:read
1642 Return the full absolute name of the file that was executed to
1643 create a process running on the remote system.
1646 Select the filesystem on which vFile: operations with filename
1647 arguments will operate. This is required for GDB to be able to
1648 access files on remote targets where the remote stub does not
1649 share a common filesystem with the inferior(s).
1652 Indicates that a fork system call was executed.
1655 Indicates that a vfork system call was executed.
1657 vforkdone stop reason
1658 Indicates that a vfork child of the specified process has executed
1659 an exec or exit, allowing the vfork parent to resume execution.
1661 fork-events and vfork-events features in qSupported
1662 The qSupported packet allows GDB to request support for fork and
1663 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1664 and the qSupported response can contain the corresponding
1665 'stubfeatures'. Set and show commands can be used to display
1666 whether these features are enabled.
1668 * Extended-remote fork events
1670 ** GDB now has support for fork events on extended-remote Linux
1671 targets. For targets with Linux kernels 2.5.60 and later, this
1672 enables follow-fork-mode and detach-on-fork for both fork and
1673 vfork, as well as fork and vfork catchpoints.
1675 * The info record command now shows the recording format and the
1676 branch tracing configuration for the current thread when using
1677 the btrace record target.
1678 For the BTS format, it shows the ring buffer size.
1680 * GDB now has support for DTrace USDT (Userland Static Defined
1681 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1683 * GDB now supports access to vector registers on S/390 GNU/Linux
1686 * Removed command line options
1688 -xdb HP-UX XDB compatibility mode.
1690 * Removed targets and native configurations
1692 HP/PA running HP-UX hppa*-*-hpux*
1693 Itanium running HP-UX ia64-*-hpux*
1695 * New configure options
1698 This configure option allows the user to build GDB with support for
1699 Intel Processor Trace (default: auto). This requires libipt.
1701 --with-libipt-prefix=PATH
1702 Specify the path to the version of libipt that GDB should use.
1703 $PATH/include should contain the intel-pt.h header and
1704 $PATH/lib should contain the libipt.so library.
1706 *** Changes in GDB 7.9.1
1710 ** Xmethods can now specify a result type.
1712 *** Changes in GDB 7.9
1714 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1718 ** You can now access frame registers from Python scripts.
1719 ** New attribute 'producer' for gdb.Symtab objects.
1720 ** gdb.Objfile objects have a new attribute "progspace",
1721 which is the gdb.Progspace object of the containing program space.
1722 ** gdb.Objfile objects have a new attribute "owner".
1723 ** gdb.Objfile objects have a new attribute "build_id",
1724 which is the build ID generated when the file was built.
1725 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1726 ** A new event "gdb.clear_objfiles" has been added, triggered when
1727 selecting a new file to debug.
1728 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1729 ** New function gdb.lookup_objfile.
1731 New events which are triggered when GDB modifies the state of the
1734 ** gdb.events.inferior_call_pre: Function call is about to be made.
1735 ** gdb.events.inferior_call_post: Function call has just been made.
1736 ** gdb.events.memory_changed: A memory location has been altered.
1737 ** gdb.events.register_changed: A register has been altered.
1739 * New Python-based convenience functions:
1741 ** $_caller_is(name [, number_of_frames])
1742 ** $_caller_matches(regexp [, number_of_frames])
1743 ** $_any_caller_is(name [, number_of_frames])
1744 ** $_any_caller_matches(regexp [, number_of_frames])
1746 * GDB now supports the compilation and injection of source code into
1747 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1748 to compile the source code to object code, and if successful, inject
1749 and execute that code within the current context of the inferior.
1750 Currently the C language is supported. The commands used to
1751 interface with this new feature are:
1753 compile code [-raw|-r] [--] [source code]
1754 compile file [-raw|-r] filename
1758 demangle [-l language] [--] name
1759 Demangle "name" in the specified language, or the current language
1760 if elided. This command is renamed from the "maint demangle" command.
1761 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1762 as "maint demangler-warning".
1764 queue-signal signal-name-or-number
1765 Queue a signal to be delivered to the thread when it is resumed.
1767 add-auto-load-scripts-directory directory
1768 Add entries to the list of directories from which to load auto-loaded
1771 maint print user-registers
1772 List all currently available "user" registers.
1774 compile code [-r|-raw] [--] [source code]
1775 Compile, inject, and execute in the inferior the executable object
1776 code produced by compiling the provided source code.
1778 compile file [-r|-raw] filename
1779 Compile and inject into the inferior the executable object code
1780 produced by compiling the source code stored in the filename
1783 * On resume, GDB now always passes the signal the program had stopped
1784 for to the thread the signal was sent to, even if the user changed
1785 threads before resuming. Previously GDB would often (but not
1786 always) deliver the signal to the thread that happens to be current
1789 * Conversely, the "signal" command now consistently delivers the
1790 requested signal to the current thread. GDB now asks for
1791 confirmation if the program had stopped for a signal and the user
1792 switched threads meanwhile.
1794 * "breakpoint always-inserted" modes "off" and "auto" merged.
1796 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1797 won't remove breakpoints from the target until all threads stop,
1798 even in non-stop mode. The "auto" mode has been removed, and "off"
1799 is now the default mode.
1803 set debug symbol-lookup
1804 show debug symbol-lookup
1805 Control display of debugging info regarding symbol lookup.
1809 ** The -list-thread-groups command outputs an exit-code field for
1810 inferiors that have exited.
1814 MIPS SDE mips*-sde*-elf*
1818 Support for these obsolete configurations has been removed.
1820 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1821 SGI Irix-5.x mips-*-irix5*
1822 SGI Irix-6.x mips-*-irix6*
1823 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1824 VAX running Ultrix vax-*-ultrix*
1826 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1827 and "assf"), have been removed. Use the "sharedlibrary" command, or
1828 its alias "share", instead.
1830 *** Changes in GDB 7.8
1832 * New command line options
1835 This is an alias for the --data-directory option.
1837 * GDB supports printing and modifying of variable length automatic arrays
1838 as specified in ISO C99.
1840 * The ARM simulator now supports instruction level tracing
1841 with or without disassembly.
1845 GDB now has support for scripting using Guile. Whether this is
1846 available is determined at configure time.
1847 Guile version 2.0 or greater is required.
1848 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1850 * New commands (for set/show, see "New options" below)
1854 Invoke CODE by passing it to the Guile interpreter.
1858 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1860 info auto-load guile-scripts [regexp]
1861 Print the list of automatically loaded Guile scripts.
1863 * The source command is now capable of sourcing Guile scripts.
1864 This feature is dependent on the debugger being built with Guile support.
1868 set print symbol-loading (off|brief|full)
1869 show print symbol-loading
1870 Control whether to print informational messages when loading symbol
1871 information for a file. The default is "full", but when debugging
1872 programs with large numbers of shared libraries the amount of output
1873 becomes less useful.
1875 set guile print-stack (none|message|full)
1876 show guile print-stack
1877 Show a stack trace when an error is encountered in a Guile script.
1879 set auto-load guile-scripts (on|off)
1880 show auto-load guile-scripts
1881 Control auto-loading of Guile script files.
1883 maint ada set ignore-descriptive-types (on|off)
1884 maint ada show ignore-descriptive-types
1885 Control whether the debugger should ignore descriptive types in Ada
1886 programs. The default is not to ignore the descriptive types. See
1887 the user manual for more details on descriptive types and the intended
1888 usage of this option.
1890 set auto-connect-native-target
1892 Control whether GDB is allowed to automatically connect to the
1893 native target for the run, attach, etc. commands when not connected
1894 to any target yet. See also "target native" below.
1896 set record btrace replay-memory-access (read-only|read-write)
1897 show record btrace replay-memory-access
1898 Control what memory accesses are allowed during replay.
1900 maint set target-async (on|off)
1901 maint show target-async
1902 This controls whether GDB targets operate in synchronous or
1903 asynchronous mode. Normally the default is asynchronous, if it is
1904 available; but this can be changed to more easily debug problems
1905 occurring only in synchronous mode.
1907 set mi-async (on|off)
1909 Control whether MI asynchronous mode is preferred. This supersedes
1910 "set target-async" of previous GDB versions.
1912 * "set target-async" is deprecated as a CLI option and is now an alias
1913 for "set mi-async" (only puts MI into async mode).
1915 * Background execution commands (e.g., "c&", "s&", etc.) are now
1916 possible ``out of the box'' if the target supports them. Previously
1917 the user would need to explicitly enable the possibility with the
1918 "set target-async on" command.
1920 * New features in the GDB remote stub, GDBserver
1922 ** New option --debug-format=option1[,option2,...] allows one to add
1923 additional text to each output. At present only timestamps
1924 are supported: --debug-format=timestamps.
1925 Timestamps can also be turned on with the
1926 "monitor set debug-format timestamps" command from GDB.
1928 * The 'record instruction-history' command now starts counting instructions
1929 at one. This also affects the instruction ranges reported by the
1930 'record function-call-history' command when given the /i modifier.
1932 * The command 'record function-call-history' supports a new modifier '/c' to
1933 indent the function names based on their call stack depth.
1934 The fields for the '/i' and '/l' modifier have been reordered.
1935 The source line range is now prefixed with 'at'.
1936 The instruction range is now prefixed with 'inst'.
1937 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1938 "record instruction-history" and "list" commands.
1940 * The ranges given as arguments to the 'record function-call-history' and
1941 'record instruction-history' commands are now inclusive.
1943 * The btrace record target now supports the 'record goto' command.
1944 For locations inside the execution trace, the back trace is computed
1945 based on the information stored in the execution trace.
1947 * The btrace record target supports limited reverse execution and replay.
1948 The target does not record data and therefore does not allow reading
1949 memory or registers.
1951 * The "catch syscall" command now works on s390*-linux* targets.
1953 * The "compare-sections" command is no longer specific to target
1954 remote. It now works with all targets.
1956 * All native targets are now consistently called "native".
1957 Consequently, the "target child", "target GNU", "target djgpp",
1958 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1959 commands have been replaced with "target native". The QNX/NTO port
1960 leaves the "procfs" target in place and adds a "native" target for
1961 consistency with other ports. The impact on users should be minimal
1962 as these commands previously either throwed an error, or were
1963 no-ops. The target's name is visible in the output of the following
1964 commands: "help target", "info target", "info files", "maint print
1967 * The "target native" command now connects to the native target. This
1968 can be used to launch native programs even when "set
1969 auto-connect-native-target" is set to off.
1971 * GDB now supports access to Intel MPX registers on GNU/Linux.
1973 * Support for Intel AVX-512 registers on GNU/Linux.
1974 Support displaying and modifying Intel AVX-512 registers
1975 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1977 * New remote packets
1979 qXfer:btrace:read's annex
1980 The qXfer:btrace:read packet supports a new annex 'delta' to read
1981 branch trace incrementally.
1985 ** Valid Python operations on gdb.Value objects representing
1986 structs/classes invoke the corresponding overloaded operators if
1988 ** New `Xmethods' feature in the Python API. Xmethods are
1989 additional methods or replacements for existing methods of a C++
1990 class. This feature is useful for those cases where a method
1991 defined in C++ source code could be inlined or optimized out by
1992 the compiler, making it unavailable to GDB.
1995 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1997 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1998 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1999 its alias "share", instead.
2001 * The commands "set remotebaud" and "show remotebaud" are no longer
2002 supported. Use "set serial baud" and "show serial baud" (respectively)
2007 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2008 target-async". The latter is left as a deprecated alias of the
2009 former for backward compatibility. If the target supports it,
2010 CLI background execution commands are now always possible by
2011 default, independently of whether the frontend stated a
2012 preference for asynchronous execution with "-gdb-set mi-async".
2013 Previously "-gdb-set target-async off" affected both MI execution
2014 commands and CLI execution commands.
2016 *** Changes in GDB 7.7
2018 * Improved support for process record-replay and reverse debugging on
2019 arm*-linux* targets. Support for thumb32 and syscall instruction
2020 recording has been added.
2022 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2024 * GDB now supports Fission DWP file format version 2.
2025 http://gcc.gnu.org/wiki/DebugFission
2027 * New convenience function "$_isvoid", to check whether an expression
2028 is void. A void expression is an expression where the type of the
2029 result is "void". For example, some convenience variables may be
2030 "void" when evaluated (e.g., "$_exitcode" before the execution of
2031 the program being debugged; or an undefined convenience variable).
2032 Another example, when calling a function whose return type is
2035 * The "maintenance print objfiles" command now takes an optional regexp.
2037 * The "catch syscall" command now works on arm*-linux* targets.
2039 * GDB now consistently shows "<not saved>" when printing values of
2040 registers the debug info indicates have not been saved in the frame
2041 and there's nowhere to retrieve them from
2042 (callee-saved/call-clobbered registers):
2047 (gdb) info registers rax
2050 Before, the former would print "<optimized out>", and the latter
2051 "*value not available*".
2053 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2058 ** Frame filters and frame decorators have been added.
2059 ** Temporary breakpoints are now supported.
2060 ** Line tables representation has been added.
2061 ** New attribute 'parent_type' for gdb.Field objects.
2062 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2063 ** New attribute 'name' for gdb.Type objects.
2067 Nios II ELF nios2*-*-elf
2068 Nios II GNU/Linux nios2*-*-linux
2069 Texas Instruments MSP430 msp430*-*-elf
2071 * Removed native configurations
2073 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2074 been removed. ELF variants of these configurations are kept supported.
2076 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2077 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2078 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2079 i[34567]86-*-openbsd3.[0-3]
2080 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2081 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2082 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2086 Like "catch throw", but catches a re-thrown exception.
2087 maint check-psymtabs
2088 Renamed from old "maint check-symtabs".
2090 Perform consistency checks on symtabs.
2091 maint expand-symtabs
2092 Expand symtabs matching an optional regexp.
2095 Display the details of GDB configure-time options.
2097 maint set|show per-command
2098 maint set|show per-command space
2099 maint set|show per-command time
2100 maint set|show per-command symtab
2101 Enable display of per-command gdb resource usage.
2103 remove-symbol-file FILENAME
2104 remove-symbol-file -a ADDRESS
2105 Remove a symbol file added via add-symbol-file. The file to remove
2106 can be identified by its filename or by an address that lies within
2107 the boundaries of this symbol file in memory.
2110 info exceptions REGEXP
2111 Display the list of Ada exceptions defined in the program being
2112 debugged. If provided, only the exceptions whose names match REGEXP
2117 set debug symfile off|on
2119 Control display of debugging info regarding reading symbol files and
2120 symbol tables within those files
2122 set print raw frame-arguments
2123 show print raw frame-arguments
2124 Set/show whether to print frame arguments in raw mode,
2125 disregarding any defined pretty-printers.
2127 set remote trace-status-packet
2128 show remote trace-status-packet
2129 Set/show the use of remote protocol qTStatus packet.
2133 Control display of debugging messages related to Nios II targets.
2137 Control whether target-assisted range stepping is enabled.
2139 set startup-with-shell
2140 show startup-with-shell
2141 Specifies whether Unix child processes are started via a shell or
2146 Use the target memory cache for accesses to the code segment. This
2147 improves performance of remote debugging (particularly disassembly).
2149 * You can now use a literal value 'unlimited' for options that
2150 interpret 0 or -1 as meaning "unlimited". E.g., "set
2151 trace-buffer-size unlimited" is now an alias for "set
2152 trace-buffer-size -1" and "set height unlimited" is now an alias for
2155 * The "set debug symtab-create" debugging option of GDB has been changed to
2156 accept a verbosity level. 0 means "off", 1 provides basic debugging
2157 output, and values of 2 or greater provides more verbose output.
2159 * New command-line options
2161 Display the details of GDB configure-time options.
2163 * The command 'tsave' can now support new option '-ctf' to save trace
2164 buffer in Common Trace Format.
2166 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2169 * GDB now implements the the C++ 'typeid' operator.
2171 * The new convenience variable $_exception holds the exception being
2172 thrown or caught at an exception-related catchpoint.
2174 * The exception-related catchpoints, like "catch throw", now accept a
2175 regular expression which can be used to filter exceptions by type.
2177 * The new convenience variable $_exitsignal is automatically set to
2178 the terminating signal number when the program being debugged dies
2179 due to an uncaught signal.
2183 ** All MI commands now accept an optional "--language" option.
2184 Support for this feature can be verified by using the "-list-features"
2185 command, which should contain "language-option".
2187 ** The new command -info-gdb-mi-command allows the user to determine
2188 whether a GDB/MI command is supported or not.
2190 ** The "^error" result record returned when trying to execute an undefined
2191 GDB/MI command now provides a variable named "code" whose content is the
2192 "undefined-command" error code. Support for this feature can be verified
2193 by using the "-list-features" command, which should contain
2194 "undefined-command-error-code".
2196 ** The -trace-save MI command can optionally save trace buffer in Common
2199 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2201 ** The command -data-list-register-values now accepts an optional
2202 "--skip-unavailable" option. When used, only the available registers
2205 ** The new command -trace-frame-collected dumps collected variables,
2206 computed expressions, tvars, memory and registers in a traceframe.
2208 ** The commands -stack-list-locals, -stack-list-arguments and
2209 -stack-list-variables now accept an option "--skip-unavailable".
2210 When used, only the available locals or arguments are displayed.
2212 ** The -exec-run command now accepts an optional "--start" option.
2213 When used, the command follows the same semantics as the "start"
2214 command, stopping the program's execution at the start of its
2215 main subprogram. Support for this feature can be verified using
2216 the "-list-features" command, which should contain
2217 "exec-run-start-option".
2219 ** The new commands -catch-assert and -catch-exceptions insert
2220 catchpoints stopping the program when Ada exceptions are raised.
2222 ** The new command -info-ada-exceptions provides the equivalent of
2223 the new "info exceptions" command.
2225 * New system-wide configuration scripts
2226 A GDB installation now provides scripts suitable for use as system-wide
2227 configuration scripts for the following systems:
2231 * GDB now supports target-assigned range stepping with remote targets.
2232 This improves the performance of stepping source lines by reducing
2233 the number of control packets from/to GDB. See "New remote packets"
2236 * GDB now understands the element 'tvar' in the XML traceframe info.
2237 It has the id of the collected trace state variables.
2239 * On S/390 targets that provide the transactional-execution feature,
2240 the program interruption transaction diagnostic block (TDB) is now
2241 represented as a number of additional "registers" in GDB.
2243 * New remote packets
2247 The vCont packet supports a new 'r' action, that tells the remote
2248 stub to step through an address range itself, without GDB
2249 involvemement at each single-step.
2251 qXfer:libraries-svr4:read's annex
2252 The previously unused annex of the qXfer:libraries-svr4:read packet
2253 is now used to support passing an argument list. The remote stub
2254 reports support for this argument list to GDB's qSupported query.
2255 The defined arguments are "start" and "prev", used to reduce work
2256 necessary for library list updating, resulting in significant
2259 * New features in the GDB remote stub, GDBserver
2261 ** GDBserver now supports target-assisted range stepping. Currently
2262 enabled on x86/x86_64 GNU/Linux targets.
2264 ** GDBserver now adds element 'tvar' in the XML in the reply to
2265 'qXfer:traceframe-info:read'. It has the id of the collected
2266 trace state variables.
2268 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2271 * New 'z' formatter for printing and examining memory, this displays the
2272 value as hexadecimal zero padded on the left to the size of the type.
2274 * GDB can now use Windows x64 unwinding data.
2276 * The "set remotebaud" command has been replaced by "set serial baud".
2277 Similarly, "show remotebaud" has been replaced by "show serial baud".
2278 The "set remotebaud" and "show remotebaud" commands are still available
2279 to provide backward compatibility with older versions of GDB.
2281 *** Changes in GDB 7.6
2283 * Target record has been renamed to record-full.
2284 Record/replay is now enabled with the "record full" command.
2285 This also affects settings that are associated with full record/replay
2286 that have been moved from "set/show record" to "set/show record full":
2288 set|show record full insn-number-max
2289 set|show record full stop-at-limit
2290 set|show record full memory-query
2292 * A new record target "record-btrace" has been added. The new target
2293 uses hardware support to record the control-flow of a process. It
2294 does not support replaying the execution, but it implements the
2295 below new commands for investigating the recorded execution log.
2296 This new recording method can be enabled using:
2300 The "record-btrace" target is only available on Intel Atom processors
2301 and requires a Linux kernel 2.6.32 or later.
2303 * Two new commands have been added for record/replay to give information
2304 about the recorded execution without having to replay the execution.
2305 The commands are only supported by "record btrace".
2307 record instruction-history prints the execution history at
2308 instruction granularity
2310 record function-call-history prints the execution history at
2311 function granularity
2313 * New native configurations
2315 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2316 FreeBSD/powerpc powerpc*-*-freebsd
2317 x86_64/Cygwin x86_64-*-cygwin*
2318 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2322 ARM AArch64 aarch64*-*-elf
2323 ARM AArch64 GNU/Linux aarch64*-*-linux
2324 Lynx 178 PowerPC powerpc-*-lynx*178
2325 x86_64/Cygwin x86_64-*-cygwin*
2326 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2328 * If the configured location of system.gdbinit file (as given by the
2329 --with-system-gdbinit option at configure time) is in the
2330 data-directory (as specified by --with-gdb-datadir at configure
2331 time) or in one of its subdirectories, then GDB will look for the
2332 system-wide init file in the directory specified by the
2333 --data-directory command-line option.
2335 * New command line options:
2337 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2338 other initialization files, unlike -nx which disables all of them.
2340 * Removed command line options
2342 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2345 * The 'ptype' and 'whatis' commands now accept an argument to control
2348 * 'info proc' now works on some core files.
2352 ** Vectors can be created with gdb.Type.vector.
2354 ** Python's atexit.register now works in GDB.
2356 ** Types can be pretty-printed via a Python API.
2358 ** Python 3 is now supported (in addition to Python 2.4 or later)
2360 ** New class gdb.Architecture exposes GDB's internal representation
2361 of architecture in the Python API.
2363 ** New method Frame.architecture returns the gdb.Architecture object
2364 corresponding to the frame's architecture.
2366 * New Python-based convenience functions:
2368 ** $_memeq(buf1, buf2, length)
2369 ** $_streq(str1, str2)
2371 ** $_regex(str, regex)
2373 * The 'cd' command now defaults to using '~' (the home directory) if not
2376 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2377 default for GCC since November 2000.
2379 * The command 'forward-search' can now be abbreviated as 'fo'.
2381 * The command 'info tracepoints' can now display 'installed on target'
2382 or 'not installed on target' for each non-pending location of tracepoint.
2384 * New configure options
2386 --enable-libmcheck/--disable-libmcheck
2387 By default, development versions are built with -lmcheck on hosts
2388 that support it, in order to help track memory corruption issues.
2389 Release versions, on the other hand, are built without -lmcheck
2390 by default. The --enable-libmcheck/--disable-libmcheck configure
2391 options allow the user to override that default.
2392 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2393 This configure option allows the user to build GDB with
2394 libbabeltrace using which GDB can read Common Trace Format data.
2396 * New commands (for set/show, see "New options" below)
2399 Catch signals. This is similar to "handle", but allows commands and
2400 conditions to be attached.
2403 List the BFDs known to GDB.
2405 python-interactive [command]
2407 Start a Python interactive prompt, or evaluate the optional command
2408 and print the result of expressions.
2411 "py" is a new alias for "python".
2413 enable type-printer [name]...
2414 disable type-printer [name]...
2415 Enable or disable type printers.
2419 ** For the Renesas Super-H architecture, the "regs" command has been removed
2420 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2425 set print type methods (on|off)
2426 show print type methods
2427 Control whether method declarations are displayed by "ptype".
2428 The default is to show them.
2430 set print type typedefs (on|off)
2431 show print type typedefs
2432 Control whether typedef definitions are displayed by "ptype".
2433 The default is to show them.
2435 set filename-display basename|relative|absolute
2436 show filename-display
2437 Control the way in which filenames is displayed.
2438 The default is "relative", which preserves previous behavior.
2440 set trace-buffer-size
2441 show trace-buffer-size
2442 Request target to change the size of trace buffer.
2444 set remote trace-buffer-size-packet auto|on|off
2445 show remote trace-buffer-size-packet
2446 Control the use of the remote protocol `QTBuffer:size' packet.
2450 Control display of debugging messages related to ARM AArch64.
2453 set debug coff-pe-read
2454 show debug coff-pe-read
2455 Control display of debugging messages related to reading of COFF/PE
2460 Control display of debugging messages related to Mach-O symbols
2463 set debug notification
2464 show debug notification
2465 Control display of debugging info for async remote notification.
2469 ** Command parameter changes are now notified using new async record
2470 "=cmd-param-changed".
2471 ** Trace frame changes caused by command "tfind" are now notified using
2472 new async record "=traceframe-changed".
2473 ** The creation, deletion and modification of trace state variables
2474 are now notified using new async records "=tsv-created",
2475 "=tsv-deleted" and "=tsv-modified".
2476 ** The start and stop of process record are now notified using new
2477 async record "=record-started" and "=record-stopped".
2478 ** Memory changes are now notified using new async record
2480 ** The data-disassemble command response will include a "fullname" field
2481 containing the absolute file name when source has been requested.
2482 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2483 command, to allow pattern filling of memory areas.
2484 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2485 library load/unload events.
2486 ** The response to breakpoint commands and breakpoint async records
2487 includes an "installed" field containing a boolean state about each
2488 non-pending tracepoint location is whether installed on target or not.
2489 ** Output of the "-trace-status" command includes a "trace-file" field
2490 containing the name of the trace file being examined. This field is
2491 optional, and only present when examining a trace file.
2492 ** The "fullname" field is now always present along with the "file" field,
2493 even if the file cannot be found by GDB.
2495 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2496 You must have the LZMA library available when configuring GDB for this
2497 feature to be enabled. For more information, see:
2498 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2500 * New remote packets
2503 Set the size of trace buffer. The remote stub reports support for this
2504 packet to gdb's qSupported query.
2507 Enable Branch Trace Store (BTS)-based branch tracing for the current
2508 thread. The remote stub reports support for this packet to gdb's
2512 Disable branch tracing for the current thread. The remote stub reports
2513 support for this packet to gdb's qSupported query.
2516 Read the traced branches for the current thread. The remote stub
2517 reports support for this packet to gdb's qSupported query.
2519 *** Changes in GDB 7.5
2521 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2522 for more x32 ABI info.
2524 * GDB now supports access to MIPS DSP registers on Linux targets.
2526 * GDB now supports debugging microMIPS binaries.
2528 * The "info os" command on GNU/Linux can now display information on
2529 several new classes of objects managed by the operating system:
2530 "info os procgroups" lists process groups
2531 "info os files" lists file descriptors
2532 "info os sockets" lists internet-domain sockets
2533 "info os shm" lists shared-memory regions
2534 "info os semaphores" lists semaphores
2535 "info os msg" lists message queues
2536 "info os modules" lists loaded kernel modules
2538 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2539 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2540 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2541 options and inspect the probe arguments using the new $_probe_arg family
2542 of convenience variables. You can obtain more information about SystemTap
2543 in <http://sourceware.org/systemtap/>.
2545 * GDB now supports reversible debugging on ARM, it allows you to
2546 debug basic ARM and THUMB instructions, and provides
2547 record/replay support.
2549 * The option "symbol-reloading" has been deleted as it is no longer used.
2553 ** GDB commands implemented in Python can now be put in command class
2556 ** The "maint set python print-stack on|off" is now deleted.
2558 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2559 apply "flag enum"-style pretty-printing to any enum.
2561 ** gdb.lookup_symbol can now work when there is no current frame.
2563 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2564 the source at which the symbol was defined.
2566 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2567 method 'value'. The former indicates whether the symbol needs a
2568 frame in order to compute its value, and the latter computes the
2571 ** A new method 'referenced_value' on gdb.Value objects which can
2572 dereference pointer as well as C++ reference values.
2574 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2575 which return the global and static blocks (as gdb.Block objects),
2576 of the underlying symbol table, respectively.
2578 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2579 object associated with a PC value.
2581 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2582 of the address range occupied by code for the current source line.
2584 * Go language support.
2585 GDB now supports debugging programs written in the Go programming
2588 * GDBserver now supports stdio connections.
2589 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2591 * The binary "gdbtui" can no longer be built or installed.
2592 Use "gdb -tui" instead.
2594 * GDB will now print "flag" enums specially. A flag enum is one where
2595 all the enumerator values have no bits in common when pairwise
2596 "and"ed. When printing a value whose type is a flag enum, GDB will
2597 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2598 (gdb) print (enum E) 3
2601 * The filename part of a linespec will now match trailing components
2602 of a source file name. For example, "break gcc/expr.c:1000" will
2603 now set a breakpoint in build/gcc/expr.c, but not
2604 build/libcpp/expr.c.
2606 * The "info proc" and "generate-core-file" commands will now also
2607 work on remote targets connected to GDBserver on Linux.
2609 * The command "info catch" has been removed. It has been disabled
2610 since December 2007.
2612 * The "catch exception" and "catch assert" commands now accept
2613 a condition at the end of the command, much like the "break"
2614 command does. For instance:
2616 (gdb) catch exception Constraint_Error if Barrier = True
2618 Previously, it was possible to add a condition to such catchpoints,
2619 but it had to be done as a second step, after the catchpoint had been
2620 created, using the "condition" command.
2622 * The "info static-tracepoint-marker" command will now also work on
2623 native Linux targets with in-process agent.
2625 * GDB can now set breakpoints on inlined functions.
2627 * The .gdb_index section has been updated to include symbols for
2628 inlined functions. GDB will ignore older .gdb_index sections by
2629 default, which could cause symbol files to be loaded more slowly
2630 until their .gdb_index sections can be recreated. The new command
2631 "set use-deprecated-index-sections on" will cause GDB to use any older
2632 .gdb_index sections it finds. This will restore performance, but the
2633 ability to set breakpoints on inlined functions will be lost in symbol
2634 files with older .gdb_index sections.
2636 The .gdb_index section has also been updated to record more information
2637 about each symbol. This speeds up the "info variables", "info functions"
2638 and "info types" commands when used with programs having the .gdb_index
2639 section, as well as speeding up debugging with shared libraries using
2640 the .gdb_index section.
2642 * Ada support for GDB/MI Variable Objects has been added.
2644 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2649 ** New command -info-os is the MI equivalent of "info os".
2651 ** Output logs ("set logging" and related) now include MI output.
2655 ** "set use-deprecated-index-sections on|off"
2656 "show use-deprecated-index-sections on|off"
2657 Controls the use of deprecated .gdb_index sections.
2659 ** "catch load" and "catch unload" can be used to stop when a shared
2660 library is loaded or unloaded, respectively.
2662 ** "enable count" can be used to auto-disable a breakpoint after
2665 ** "info vtbl" can be used to show the virtual method tables for
2666 C++ and Java objects.
2668 ** "explore" and its sub commands "explore value" and "explore type"
2669 can be used to recursively explore values and types of
2670 expressions. These commands are available only if GDB is
2671 configured with '--with-python'.
2673 ** "info auto-load" shows status of all kinds of auto-loaded files,
2674 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2675 sequences of commands files, "info auto-load python-scripts"
2676 shows status of auto-loading Python script files,
2677 "info auto-load local-gdbinit" shows status of loading init file
2678 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2679 status of inferior specific thread debugging shared library loading.
2681 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2682 and "show auto-load-scripts" commands have been deprecated, use their
2683 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2684 and "show auto-load python-scripts" counterparts instead.
2686 ** "dprintf location,format,args..." creates a dynamic printf, which
2687 is basically a breakpoint that does a printf and immediately
2688 resumes your program's execution, so it is like a printf that you
2689 can insert dynamically at runtime instead of at compiletime.
2691 ** "set print symbol"
2693 Controls whether GDB attempts to display the symbol, if any,
2694 corresponding to addresses it prints. This defaults to "on", but
2695 you can set it to "off" to restore GDB's previous behavior.
2697 * Deprecated commands
2699 ** For the Renesas Super-H architecture, the "regs" command has been
2700 deprecated, and "info all-registers" should be used instead.
2704 Renesas RL78 rl78-*-elf
2705 HP OpenVMS ia64 ia64-hp-openvms*
2707 * GDBserver supports evaluation of breakpoint conditions. When
2708 support is advertised by GDBserver, GDB may be told to send the
2709 breakpoint conditions in bytecode form to GDBserver. GDBserver
2710 will only report the breakpoint trigger to GDB when its condition
2715 set mips compression
2716 show mips compression
2717 Select the compressed ISA encoding used in functions that have no symbol
2718 information available. The encoding can be set to either of:
2721 and is updated automatically from ELF file flags if available.
2723 set breakpoint condition-evaluation
2724 show breakpoint condition-evaluation
2725 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2726 GDBserver ("target"). Default option "auto" chooses the most efficient
2728 This option can improve debugger efficiency depending on the speed of the
2732 Disable auto-loading globally.
2735 Show auto-loading setting of all kinds of auto-loaded files.
2737 set auto-load gdb-scripts on|off
2738 show auto-load gdb-scripts
2739 Control auto-loading of GDB canned sequences of commands files.
2741 set auto-load python-scripts on|off
2742 show auto-load python-scripts
2743 Control auto-loading of Python script files.
2745 set auto-load local-gdbinit on|off
2746 show auto-load local-gdbinit
2747 Control loading of init file (.gdbinit) from current directory.
2749 set auto-load libthread-db on|off
2750 show auto-load libthread-db
2751 Control auto-loading of inferior specific thread debugging shared library.
2753 set auto-load scripts-directory <dir1>[:<dir2>...]
2754 show auto-load scripts-directory
2755 Set a list of directories from which to load auto-loaded scripts.
2756 Automatically loaded Python scripts and GDB scripts are located in one
2757 of the directories listed by this option.
2758 The delimiter (':' above) may differ according to the host platform.
2760 set auto-load safe-path <dir1>[:<dir2>...]
2761 show auto-load safe-path
2762 Set a list of directories from which it is safe to auto-load files.
2763 The delimiter (':' above) may differ according to the host platform.
2765 set debug auto-load on|off
2766 show debug auto-load
2767 Control display of debugging info for auto-loading the files above.
2769 set dprintf-style gdb|call|agent
2771 Control the way in which a dynamic printf is performed; "gdb"
2772 requests a GDB printf command, while "call" causes dprintf to call a
2773 function in the inferior. "agent" requests that the target agent
2774 (such as GDBserver) do the printing.
2776 set dprintf-function <expr>
2777 show dprintf-function
2778 set dprintf-channel <expr>
2779 show dprintf-channel
2780 Set the function and optional first argument to the call when using
2781 the "call" style of dynamic printf.
2783 set disconnected-dprintf on|off
2784 show disconnected-dprintf
2785 Control whether agent-style dynamic printfs continue to be in effect
2786 after GDB disconnects.
2788 * New configure options
2790 --with-auto-load-dir
2791 Configure default value for the 'set auto-load scripts-directory'
2792 setting above. It defaults to '$debugdir:$datadir/auto-load',
2793 $debugdir representing global debugging info directories (available
2794 via 'show debug-file-directory') and $datadir representing GDB's data
2795 directory (available via 'show data-directory').
2797 --with-auto-load-safe-path
2798 Configure default value for the 'set auto-load safe-path' setting
2799 above. It defaults to the --with-auto-load-dir setting.
2801 --without-auto-load-safe-path
2802 Set 'set auto-load safe-path' to '/', effectively disabling this
2805 * New remote packets
2807 z0/z1 conditional breakpoints extension
2809 The z0/z1 breakpoint insertion packets have been extended to carry
2810 a list of conditional expressions over to the remote stub depending on the
2811 condition evaluation mode. The use of this extension can be controlled
2812 via the "set remote conditional-breakpoints-packet" command.
2816 Specify the signals which the remote stub may pass to the debugged
2817 program without GDB involvement.
2819 * New command line options
2821 --init-command=FILE, -ix Like --command, -x but execute it
2822 before loading inferior.
2823 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2824 execute it before loading inferior.
2826 *** Changes in GDB 7.4
2828 * GDB now handles ambiguous linespecs more consistently; the existing
2829 FILE:LINE support has been expanded to other types of linespecs. A
2830 breakpoint will now be set on all matching locations in all
2831 inferiors, and locations will be added or removed according to
2834 * GDB now allows you to skip uninteresting functions and files when
2835 stepping with the "skip function" and "skip file" commands.
2837 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2838 and "show remote hardware-watchpoint-length-limit". These allows to
2839 set or show the maximum length limit (in bytes) of a remote
2840 target hardware watchpoint.
2842 This allows e.g. to use "unlimited" hardware watchpoints with the
2843 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2844 watchpoints are slower than real hardware watchpoints but are
2845 significantly faster than gdb software watchpoints.
2849 ** The register_pretty_printer function in module gdb.printing now takes
2850 an optional `replace' argument. If True, the new printer replaces any
2853 ** The "maint set python print-stack on|off" command has been
2854 deprecated and will be deleted in GDB 7.5.
2855 A new command: "set python print-stack none|full|message" has
2856 replaced it. Additionally, the default for "print-stack" is
2857 now "message", which just prints the error message without
2860 ** A prompt substitution hook (prompt_hook) is now available to the
2863 ** A new Python module, gdb.prompt has been added to the GDB Python
2864 modules library. This module provides functionality for
2865 escape sequences in prompts (used by set/show
2866 extended-prompt). These escape sequences are replaced by their
2867 corresponding value.
2869 ** Python commands and convenience-functions located in
2870 'data-directory'/python/gdb/command and
2871 'data-directory'/python/gdb/function are now automatically loaded
2874 ** Blocks now provide four new attributes. global_block and
2875 static_block will return the global and static blocks
2876 respectively. is_static and is_global are boolean attributes
2877 that indicate if the block is one of those two types.
2879 ** Symbols now provide the "type" attribute, the type of the symbol.
2881 ** The "gdb.breakpoint" function has been deprecated in favor of
2884 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2885 of a function. This class is based on the "finish" command
2886 available in the CLI.
2888 ** Type objects for struct and union types now allow access to
2889 the fields using standard Python dictionary (mapping) methods.
2890 For example, "some_type['myfield']" now works, as does
2891 "some_type.items()".
2893 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2896 ** A new function, "deep_items" has been added to the gdb.types
2897 module in the GDB Python modules library. This function returns
2898 an iterator over the fields of a struct or union type. Unlike
2899 the standard Python "iteritems" method, it will recursively traverse
2900 any anonymous fields.
2904 ** "*stopped" events can report several new "reason"s, such as
2907 ** Breakpoint changes are now notified using new async records, like
2908 "=breakpoint-modified".
2910 ** New command -ada-task-info.
2912 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2913 $sdir specifies the default system locations of shared libraries.
2914 $pdir specifies the directory where the libpthread used by the application
2917 GDB no longer looks in $sdir and $pdir after it has searched the directories
2918 mentioned in libthread-db-search-path. If you want to search those
2919 directories, they must be specified in libthread-db-search-path.
2920 The default value of libthread-db-search-path on GNU/Linux and Solaris
2921 systems is now "$sdir:$pdir".
2923 $pdir is not supported by gdbserver, it is currently ignored.
2924 $sdir is supported by gdbserver.
2926 * New configure option --with-iconv-bin.
2927 When using the internationalization support like the one in the GNU C
2928 library, GDB will invoke the "iconv" program to get a list of supported
2929 character sets. If this program lives in a non-standard location, one can
2930 use this option to specify where to find it.
2932 * When natively debugging programs on PowerPC BookE processors running
2933 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2934 watchpoints, which specify a mask in addition to an address to watch.
2935 The mask specifies that some bits of an address (the bits which are
2936 reset in the mask) should be ignored when matching the address accessed
2937 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2938 section in the user manual for more details.
2940 * The new option --once causes GDBserver to stop listening for connections once
2941 the first connection is made. The listening port used by GDBserver will
2942 become available after that.
2944 * New commands "info macros" and "alias" have been added.
2946 * New function parameters suffix @entry specifies value of function parameter
2947 at the time the function got called. Entry values are available only since
2953 "!" is now an alias of the "shell" command.
2954 Note that no space is needed between "!" and SHELL COMMAND.
2958 watch EXPRESSION mask MASK_VALUE
2959 The watch command now supports the mask argument which allows creation
2960 of masked watchpoints, if the current architecture supports this feature.
2962 info auto-load-scripts [REGEXP]
2963 This command was formerly named "maintenance print section-scripts".
2964 It is now generally useful and is no longer a maintenance-only command.
2966 info macro [-all] [--] MACRO
2967 The info macro command has new options `-all' and `--'. The first for
2968 printing all definitions of a macro. The second for explicitly specifying
2969 the end of arguments and the beginning of the macro name in case the macro
2970 name starts with a hyphen.
2972 collect[/s] EXPRESSIONS
2973 The tracepoint collect command now takes an optional modifier "/s"
2974 that directs it to dereference pointer-to-character types and
2975 collect the bytes of memory up to a zero byte. The behavior is
2976 similar to what you see when you use the regular print command on a
2977 string. An optional integer following the "/s" sets a bound on the
2978 number of bytes that will be collected.
2981 The trace start command now interprets any supplied arguments as a
2982 note to be recorded with the trace run, with an effect similar to
2983 setting the variable trace-notes.
2986 The trace stop command now interprets any arguments as a note to be
2987 mentioned along with the tstatus report that the trace was stopped
2988 with a command. The effect is similar to setting the variable
2991 * Tracepoints can now be enabled and disabled at any time after a trace
2992 experiment has been started using the standard "enable" and "disable"
2993 commands. It is now possible to start a trace experiment with no enabled
2994 tracepoints; GDB will display a warning, but will allow the experiment to
2995 begin, assuming that tracepoints will be enabled as needed while the trace
2998 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2999 locations with 4-byte instructions, when they were previously
3000 limited to locations with instructions of 5 bytes or longer.
3004 set debug dwarf2-read
3005 show debug dwarf2-read
3006 Turns on or off display of debugging messages related to reading
3007 DWARF debug info. The default is off.
3009 set debug symtab-create
3010 show debug symtab-create
3011 Turns on or off display of debugging messages related to symbol table
3012 creation. The default is off.
3015 show extended-prompt
3016 Set the GDB prompt, and allow escape sequences to be inserted to
3017 display miscellaneous information (see 'help set extended-prompt'
3018 for the list of sequences). This prompt (and any information
3019 accessed through the escape sequences) is updated every time the
3020 prompt is displayed.
3022 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3023 show print entry-values
3024 Set printing of frame argument values at function entry. In some cases
3025 GDB can determine the value of function argument which was passed by the
3026 function caller, even if the value was modified inside the called function.
3028 set debug entry-values
3029 show debug entry-values
3030 Control display of debugging info for determining frame argument values at
3031 function entry and virtual tail call frames.
3033 set basenames-may-differ
3034 show basenames-may-differ
3035 Set whether a source file may have multiple base names.
3036 (A "base name" is the name of a file with the directory part removed.
3037 Example: The base name of "/home/user/hello.c" is "hello.c".)
3038 If set, GDB will canonicalize file names (e.g., expand symlinks)
3039 before comparing them. Canonicalization is an expensive operation,
3040 but it allows the same file be known by more than one base name.
3041 If not set (the default), all source files are assumed to have just
3042 one base name, and gdb will do file name comparisons more efficiently.
3048 Set a user name and notes for the current and any future trace runs.
3049 This is useful for long-running and/or disconnected traces, to
3050 inform others (or yourself) as to who is running the trace, supply
3051 contact information, or otherwise explain what is going on.
3053 set trace-stop-notes
3054 show trace-stop-notes
3055 Set a note attached to the trace run, that is displayed when the
3056 trace has been stopped by a tstop command. This is useful for
3057 instance as an explanation, if you are stopping a trace run that was
3058 started by someone else.
3060 * New remote packets
3064 Dynamically enable a tracepoint in a started trace experiment.
3068 Dynamically disable a tracepoint in a started trace experiment.
3072 Set the user and notes of the trace run.
3076 Query the current status of a tracepoint.
3080 Query the minimum length of instruction at which a fast tracepoint may
3083 * Dcache size (number of lines) and line-size are now runtime-configurable
3084 via "set dcache line" and "set dcache line-size" commands.
3088 Texas Instruments TMS320C6x tic6x-*-*
3092 Renesas RL78 rl78-*-elf
3094 *** Changes in GDB 7.3.1
3096 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3098 *** Changes in GDB 7.3
3100 * GDB has a new command: "thread find [REGEXP]".
3101 It finds the thread id whose name, target id, or thread extra info
3102 matches the given regular expression.
3104 * The "catch syscall" command now works on mips*-linux* targets.
3106 * The -data-disassemble MI command now supports modes 2 and 3 for
3107 dumping the instruction opcodes.
3109 * New command line options
3111 -data-directory DIR Specify DIR as the "data-directory".
3112 This is mostly for testing purposes.
3114 * The "maint set python auto-load on|off" command has been renamed to
3115 "set auto-load-scripts on|off".
3117 * GDB has a new command: "set directories".
3118 It is like the "dir" command except that it replaces the
3119 source path list instead of augmenting it.
3121 * GDB now understands thread names.
3123 On GNU/Linux, "info threads" will display the thread name as set by
3124 prctl or pthread_setname_np.
3126 There is also a new command, "thread name", which can be used to
3127 assign a name internally for GDB to display.
3130 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3131 has been integrated into GDB.
3135 ** The function gdb.Write now accepts an optional keyword 'stream'.
3136 This keyword, when provided, will direct the output to either
3137 stdout, stderr, or GDB's logging output.
3139 ** Parameters can now be be sub-classed in Python, and in particular
3140 you may implement the get_set_doc and get_show_doc functions.
3141 This improves how Parameter set/show documentation is processed
3142 and allows for more dynamic content.
3144 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3145 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3146 have an is_valid method.
3148 ** Breakpoints can now be sub-classed in Python, and in particular
3149 you may implement a 'stop' function that is executed each time
3150 the inferior reaches that breakpoint.
3152 ** New function gdb.lookup_global_symbol looks up a global symbol.
3154 ** GDB values in Python are now callable if the value represents a
3155 function. For example, if 'some_value' represents a function that
3156 takes two integer parameters and returns a value, you can call
3157 that function like so:
3159 result = some_value (10,20)
3161 ** Module gdb.types has been added.
3162 It contains a collection of utilities for working with gdb.Types objects:
3163 get_basic_type, has_field, make_enum_dict.
3165 ** Module gdb.printing has been added.
3166 It contains utilities for writing and registering pretty-printers.
3167 New classes: PrettyPrinter, SubPrettyPrinter,
3168 RegexpCollectionPrettyPrinter.
3169 New function: register_pretty_printer.
3171 ** New commands "info pretty-printers", "enable pretty-printer" and
3172 "disable pretty-printer" have been added.
3174 ** gdb.parameter("directories") is now available.
3176 ** New function gdb.newest_frame returns the newest frame in the
3179 ** The gdb.InferiorThread class has a new "name" attribute. This
3180 holds the thread's name.
3182 ** Python Support for Inferior events.
3183 Python scripts can add observers to be notified of events
3184 occurring in the process being debugged.
3185 The following events are currently supported:
3186 - gdb.events.cont Continue event.
3187 - gdb.events.exited Inferior exited event.
3188 - gdb.events.stop Signal received, and Breakpoint hit events.
3192 ** GDB now puts template parameters in scope when debugging in an
3193 instantiation. For example, if you have:
3195 template<int X> int func (void) { return X; }
3197 then if you step into func<5>, "print X" will show "5". This
3198 feature requires proper debuginfo support from the compiler; it
3199 was added to GCC 4.5.
3201 ** The motion commands "next", "finish", "until", and "advance" now
3202 work better when exceptions are thrown. In particular, GDB will
3203 no longer lose control of the inferior; instead, the GDB will
3204 stop the inferior at the point at which the exception is caught.
3205 This functionality requires a change in the exception handling
3206 code that was introduced in GCC 4.5.
3208 * GDB now follows GCC's rules on accessing volatile objects when
3209 reading or writing target state during expression evaluation.
3210 One notable difference to prior behavior is that "print x = 0"
3211 no longer generates a read of x; the value of the assignment is
3212 now always taken directly from the value being assigned.
3214 * GDB now has some support for using labels in the program's source in
3215 linespecs. For instance, you can use "advance label" to continue
3216 execution to a label.
3218 * GDB now has support for reading and writing a new .gdb_index
3219 section. This section holds a fast index of DWARF debugging
3220 information and can be used to greatly speed up GDB startup and
3221 operation. See the documentation for `save gdb-index' for details.
3223 * The "watch" command now accepts an optional "-location" argument.
3224 When used, this causes GDB to watch the memory referred to by the
3225 expression. Such a watchpoint is never deleted due to it going out
3228 * GDB now supports thread debugging of core dumps on GNU/Linux.
3230 GDB now activates thread debugging using the libthread_db library
3231 when debugging GNU/Linux core dumps, similarly to when debugging
3232 live processes. As a result, when debugging a core dump file, GDB
3233 is now able to display pthread_t ids of threads. For example, "info
3234 threads" shows the same output as when debugging the process when it
3235 was live. In earlier releases, you'd see something like this:
3238 * 1 LWP 6780 main () at main.c:10
3240 While now you see this:
3243 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3245 It is also now possible to inspect TLS variables when debugging core
3248 When debugging a core dump generated on a machine other than the one
3249 used to run GDB, you may need to point GDB at the correct
3250 libthread_db library with the "set libthread-db-search-path"
3251 command. See the user manual for more details on this command.
3253 * When natively debugging programs on PowerPC BookE processors running
3254 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3255 which stop execution of the inferior whenever it executes an instruction
3256 at any address within the specified range. See the "PowerPC Embedded"
3257 section in the user manual for more details.
3259 * New features in the GDB remote stub, GDBserver
3261 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3262 and i686 LynxOS (version 5.x).
3264 ** GDBserver is now supported on Blackfin Linux.
3266 * New native configurations
3268 ia64 HP-UX ia64-*-hpux*
3272 Analog Devices, Inc. Blackfin Processor bfin-*
3274 * Ada task switching is now supported on sparc-elf targets when
3275 debugging a program using the Ravenscar Profile. For more information,
3276 see the "Tasking Support when using the Ravenscar Profile" section
3277 in the GDB user manual.
3279 * Guile support was removed.
3281 * New features in the GNU simulator
3283 ** The --map-info flag lists all known core mappings.
3285 ** CFI flashes may be simulated via the "cfi" device.
3287 *** Changes in GDB 7.2
3289 * Shared library support for remote targets by default
3291 When GDB is configured for a generic, non-OS specific target, like
3292 for example, --target=arm-eabi or one of the many *-*-elf targets,
3293 GDB now queries remote stubs for loaded shared libraries using the
3294 `qXfer:libraries:read' packet. Previously, shared library support
3295 was always disabled for such configurations.
3299 ** Argument Dependent Lookup (ADL)
3301 In C++ ADL lookup directs function search to the namespaces of its
3302 arguments even if the namespace has not been imported.
3312 Here the compiler will search for `foo' in the namespace of 'b'
3313 and find A::foo. GDB now supports this. This construct is commonly
3314 used in the Standard Template Library for operators.
3316 ** Improved User Defined Operator Support
3318 In addition to member operators, GDB now supports lookup of operators
3319 defined in a namespace and imported with a `using' directive, operators
3320 defined in the global scope, operators imported implicitly from an
3321 anonymous namespace, and the ADL operators mentioned in the previous
3323 GDB now also supports proper overload resolution for all the previously
3324 mentioned flavors of operators.
3326 ** static const class members
3328 Printing of static const class members that are initialized in the
3329 class definition has been fixed.
3331 * Windows Thread Information Block access.
3333 On Windows targets, GDB now supports displaying the Windows Thread
3334 Information Block (TIB) structure. This structure is visible either
3335 by using the new command `info w32 thread-information-block' or, by
3336 dereferencing the new convenience variable named `$_tlb', a
3337 thread-specific pointer to the TIB. This feature is also supported
3338 when remote debugging using GDBserver.
3340 * Static tracepoints
3342 Static tracepoints are calls in the user program into a tracing
3343 library. One such library is a port of the LTTng kernel tracer to
3344 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3345 When debugging with GDBserver, GDB now supports combining the GDB
3346 tracepoint machinery with such libraries. For example: the user can
3347 use GDB to probe a static tracepoint marker (a call from the user
3348 program into the tracing library) with the new "strace" command (see
3349 "New commands" below). This creates a "static tracepoint" in the
3350 breakpoint list, that can be manipulated with the same feature set
3351 as fast and regular tracepoints. E.g., collect registers, local and
3352 global variables, collect trace state variables, and define
3353 tracepoint conditions. In addition, the user can collect extra
3354 static tracepoint marker specific data, by collecting the new
3355 $_sdata internal variable. When analyzing the trace buffer, you can
3356 inspect $_sdata like any other variable available to GDB. For more
3357 information, see the "Tracepoints" chapter in GDB user manual. New
3358 remote packets have been defined to support static tracepoints, see
3359 the "New remote packets" section below.
3361 * Better reconstruction of tracepoints after disconnected tracing
3363 GDB will attempt to download the original source form of tracepoint
3364 definitions when starting a trace run, and then will upload these
3365 upon reconnection to the target, resulting in a more accurate
3366 reconstruction of the tracepoints that are in use on the target.
3370 You can now exercise direct control over the ways that GDB can
3371 affect your program. For instance, you can disallow the setting of
3372 breakpoints, so that the program can run continuously (assuming
3373 non-stop mode). In addition, the "observer" variable is available
3374 to switch all of the different controls; in observer mode, GDB
3375 cannot affect the target's behavior at all, which is useful for
3376 tasks like diagnosing live systems in the field.
3378 * The new convenience variable $_thread holds the number of the
3381 * New remote packets
3385 Return the address of the Windows Thread Information Block of a given thread.
3389 In response to several of the tracepoint packets, the target may now
3390 also respond with a number of intermediate `qRelocInsn' request
3391 packets before the final result packet, to have GDB handle
3392 relocating an instruction to execute at a different address. This
3393 is particularly useful for stubs that support fast tracepoints. GDB
3394 reports support for this feature in the qSupported packet.
3398 List static tracepoint markers in the target program.
3402 List static tracepoint markers at a given address in the target
3405 qXfer:statictrace:read
3407 Read the static trace data collected (by a `collect $_sdata'
3408 tracepoint action). The remote stub reports support for this packet
3409 to gdb's qSupported query.
3413 Send the current settings of GDB's permission flags.
3417 Send part of the source (textual) form of a tracepoint definition,
3418 which includes location, conditional, and action list.
3420 * The source command now accepts a -s option to force searching for the
3421 script in the source search path even if the script name specifies
3424 * New features in the GDB remote stub, GDBserver
3426 - GDBserver now support tracepoints (including fast tracepoints, and
3427 static tracepoints). The feature is currently supported by the
3428 i386-linux and amd64-linux builds. See the "Tracepoints support
3429 in gdbserver" section in the manual for more information.
3431 GDBserver JIT compiles the tracepoint's conditional agent
3432 expression bytecode into native code whenever possible for low
3433 overhead dynamic tracepoints conditionals. For such tracepoints,
3434 an expression that examines program state is evaluated when the
3435 tracepoint is reached, in order to determine whether to capture
3436 trace data. If the condition is simple and false, processing the
3437 tracepoint finishes very quickly and no data is gathered.
3439 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3440 for static tracepoints support.
3442 - GDBserver now supports x86_64 Windows 64-bit debugging.
3444 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3445 it understands register description.
3447 * The --batch flag now disables pagination and queries.
3449 * X86 general purpose registers
3451 GDB now supports reading/writing byte, word and double-word x86
3452 general purpose registers directly. This means you can use, say,
3453 $ah or $ax to refer, respectively, to the byte register AH and
3454 16-bit word register AX that are actually portions of the 32-bit
3455 register EAX or 64-bit register RAX.
3457 * The `commands' command now accepts a range of breakpoints to modify.
3458 A plain `commands' following a command that creates multiple
3459 breakpoints affects all the breakpoints set by that command. This
3460 applies to breakpoints set by `rbreak', and also applies when a
3461 single `break' command creates multiple breakpoints (e.g.,
3462 breakpoints on overloaded c++ functions).
3464 * The `rbreak' command now accepts a filename specification as part of
3465 its argument, limiting the functions selected by the regex to those
3466 in the specified file.
3468 * Support for remote debugging Windows and SymbianOS shared libraries
3469 from Unix hosts has been improved. Non Windows GDB builds now can
3470 understand target reported file names that follow MS-DOS based file
3471 system semantics, such as file names that include drive letters and
3472 use the backslash character as directory separator. This makes it
3473 possible to transparently use the "set sysroot" and "set
3474 solib-search-path" on Unix hosts to point as host copies of the
3475 target's shared libraries. See the new command "set
3476 target-file-system-kind" described below, and the "Commands to
3477 specify files" section in the user manual for more information.
3481 eval template, expressions...
3482 Convert the values of one or more expressions under the control
3483 of the string template to a command line, and call it.
3485 set target-file-system-kind unix|dos-based|auto
3486 show target-file-system-kind
3487 Set or show the assumed file system kind for target reported file
3490 save breakpoints <filename>
3491 Save all current breakpoint definitions to a file suitable for use
3492 in a later debugging session. To read the saved breakpoint
3493 definitions, use the `source' command.
3495 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3498 info static-tracepoint-markers
3499 Display information about static tracepoint markers in the target.
3501 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3502 Define a static tracepoint by probing a marker at the given
3503 function, line, address, or marker ID.
3507 Enable and disable observer mode.
3509 set may-write-registers on|off
3510 set may-write-memory on|off
3511 set may-insert-breakpoints on|off
3512 set may-insert-tracepoints on|off
3513 set may-insert-fast-tracepoints on|off
3514 set may-interrupt on|off
3515 Set individual permissions for GDB effects on the target. Note that
3516 some of these settings can have undesirable or surprising
3517 consequences, particularly when changed in the middle of a session.
3518 For instance, disabling the writing of memory can prevent
3519 breakpoints from being inserted, cause single-stepping to fail, or
3520 even crash your program, if you disable after breakpoints have been
3521 inserted. However, GDB should not crash.
3523 set record memory-query on|off
3524 show record memory-query
3525 Control whether to stop the inferior if memory changes caused
3526 by an instruction cannot be recorded.
3531 The disassemble command now supports "start,+length" form of two arguments.
3535 ** GDB now provides a new directory location, called the python directory,
3536 where Python scripts written for GDB can be installed. The location
3537 of that directory is <data-directory>/python, where <data-directory>
3538 is the GDB data directory. For more details, see section `Scripting
3539 GDB using Python' in the manual.
3541 ** The GDB Python API now has access to breakpoints, symbols, symbol
3542 tables, program spaces, inferiors, threads and frame's code blocks.
3543 Additionally, GDB Parameters can now be created from the API, and
3544 manipulated via set/show in the CLI.
3546 ** New functions gdb.target_charset, gdb.target_wide_charset,
3547 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3549 ** New exception gdb.GdbError.
3551 ** Pretty-printers are now also looked up in the current program space.
3553 ** Pretty-printers can now be individually enabled and disabled.
3555 ** GDB now looks for names of Python scripts to auto-load in a
3556 special section named `.debug_gdb_scripts', in addition to looking
3557 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3559 * Tracepoint actions were unified with breakpoint commands. In particular,
3560 there are no longer differences in "info break" output for breakpoints and
3561 tracepoints and the "commands" command can be used for both tracepoints and
3562 regular breakpoints.
3566 ARM Symbian arm*-*-symbianelf*
3568 * D language support.
3569 GDB now supports debugging programs written in the D programming
3572 * GDB now supports the extended ptrace interface for PowerPC which is
3573 available since Linux kernel version 2.6.34. This automatically enables
3574 any hardware breakpoints and additional hardware watchpoints available in
3575 the processor. The old ptrace interface exposes just one hardware
3576 watchpoint and no hardware breakpoints.
3578 * GDB is now able to use the Data Value Compare (DVC) register available on
3579 embedded PowerPC processors to implement in hardware simple watchpoint
3580 conditions of the form:
3582 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3584 This works in native GDB running on Linux kernels with the extended ptrace
3585 interface mentioned above.
3587 *** Changes in GDB 7.1
3591 ** Namespace Support
3593 GDB now supports importing of namespaces in C++. This enables the
3594 user to inspect variables from imported namespaces. Support for
3595 namepace aliasing has also been added. So, if a namespace is
3596 aliased in the current scope (e.g. namepace C=A; ) the user can
3597 print variables using the alias (e.g. (gdb) print C::x).
3601 All known bugs relating to the printing of virtual base class were
3602 fixed. It is now possible to call overloaded static methods using a
3607 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3608 and reinterpret_cast<> are now handled by the C++ expression parser.
3612 Xilinx MicroBlaze microblaze-*-*
3617 Xilinx MicroBlaze microblaze
3620 * Multi-program debugging.
3622 GDB now has support for multi-program (a.k.a. multi-executable or
3623 multi-exec) debugging. This allows for debugging multiple inferiors
3624 simultaneously each running a different program under the same GDB
3625 session. See "Debugging Multiple Inferiors and Programs" in the
3626 manual for more information. This implied some user visible changes
3627 in the multi-inferior support. For example, "info inferiors" now
3628 lists inferiors that are not running yet or that have exited
3629 already. See also "New commands" and "New options" below.
3631 * New tracing features
3633 GDB's tracepoint facility now includes several new features:
3635 ** Trace state variables
3637 GDB tracepoints now include support for trace state variables, which
3638 are variables managed by the target agent during a tracing
3639 experiment. They are useful for tracepoints that trigger each
3640 other, so for instance one tracepoint can count hits in a variable,
3641 and then a second tracepoint has a condition that is true when the
3642 count reaches a particular value. Trace state variables share the
3643 $-syntax of GDB convenience variables, and can appear in both
3644 tracepoint actions and condition expressions. Use the "tvariable"
3645 command to create, and "info tvariables" to view; see "Trace State
3646 Variables" in the manual for more detail.
3650 GDB now includes an option for defining fast tracepoints, which
3651 targets may implement more efficiently, such as by installing a jump
3652 into the target agent rather than a trap instruction. The resulting
3653 speedup can be by two orders of magnitude or more, although the
3654 tradeoff is that some program locations on some target architectures
3655 might not allow fast tracepoint installation, for instance if the
3656 instruction to be replaced is shorter than the jump. To request a
3657 fast tracepoint, use the "ftrace" command, with syntax identical to
3658 the regular trace command.
3660 ** Disconnected tracing
3662 It is now possible to detach GDB from the target while it is running
3663 a trace experiment, then reconnect later to see how the experiment
3664 is going. In addition, a new variable disconnected-tracing lets you
3665 tell the target agent whether to continue running a trace if the
3666 connection is lost unexpectedly.
3670 GDB now has the ability to save the trace buffer into a file, and
3671 then use that file as a target, similarly to you can do with
3672 corefiles. You can select trace frames, print data that was
3673 collected in them, and use tstatus to display the state of the
3674 tracing run at the moment that it was saved. To create a trace
3675 file, use "tsave <filename>", and to use it, do "target tfile
3678 ** Circular trace buffer
3680 You can ask the target agent to handle the trace buffer as a
3681 circular buffer, discarding the oldest trace frames to make room for
3682 newer ones, by setting circular-trace-buffer to on. This feature may
3683 not be available for all target agents.
3688 The disassemble command, when invoked with two arguments, now requires
3689 the arguments to be comma-separated.
3692 The info variables command now displays variable definitions. Files
3693 which only declare a variable are not shown.
3696 The source command is now capable of sourcing Python scripts.
3697 This feature is dependent on the debugger being build with Python
3700 Related to this enhancement is also the introduction of a new command
3701 "set script-extension" (see below).
3703 * New commands (for set/show, see "New options" below)
3705 record save [<FILENAME>]
3706 Save a file (in core file format) containing the process record
3707 execution log for replay debugging at a later time.
3709 record restore <FILENAME>
3710 Restore the process record execution log that was saved at an
3711 earlier time, for replay debugging.
3713 add-inferior [-copies <N>] [-exec <FILENAME>]
3716 clone-inferior [-copies <N>] [ID]
3717 Make a new inferior ready to execute the same program another
3718 inferior has loaded.
3723 maint info program-spaces
3724 List the program spaces loaded into GDB.
3726 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3727 show remote interrupt-sequence
3728 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3729 as the sequence to the remote target in order to interrupt the execution.
3730 Ctrl-C is a default. Some system prefers BREAK which is high level of
3731 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3732 Magic SysRq g. It is BREAK signal and character 'g'.
3734 set remote interrupt-on-connect [on | off]
3735 show remote interrupt-on-connect
3736 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3737 remote target when gdb connects to it. This is needed when you debug
3740 set remotebreak [on | off]
3742 Deprecated. Use "set/show remote interrupt-sequence" instead.
3744 tvariable $NAME [ = EXP ]
3745 Create or modify a trace state variable.
3748 List trace state variables and their values.
3750 delete tvariable $NAME ...
3751 Delete one or more trace state variables.
3754 Evaluate the given expressions without collecting anything into the
3755 trace buffer. (Valid in tracepoint actions only.)
3757 ftrace FN / FILE:LINE / *ADDR
3758 Define a fast tracepoint at the given function, line, or address.
3760 * New expression syntax
3762 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3763 GDB now parses 0b101010 identically with 42.
3767 set follow-exec-mode new|same
3768 show follow-exec-mode
3769 Control whether GDB reuses the same inferior across an exec call or
3770 creates a new one. This is useful to be able to restart the old
3771 executable after the inferior having done an exec call.
3773 set default-collect EXPR, ...
3774 show default-collect
3775 Define a list of expressions to be collected at each tracepoint.
3776 This is a useful way to ensure essential items are not overlooked,
3777 such as registers or a critical global variable.
3779 set disconnected-tracing
3780 show disconnected-tracing
3781 If set to 1, the target is instructed to continue tracing if it
3782 loses its connection to GDB. If 0, the target is to stop tracing
3785 set circular-trace-buffer
3786 show circular-trace-buffer
3787 If set to on, the target is instructed to use a circular trace buffer
3788 and discard the oldest trace frames instead of stopping the trace due
3789 to a full trace buffer. If set to off, the trace stops when the buffer
3790 fills up. Some targets may not support this.
3792 set script-extension off|soft|strict
3793 show script-extension
3794 If set to "off", the debugger does not perform any script language
3795 recognition, and all sourced files are assumed to be GDB scripts.
3796 If set to "soft" (the default), files are sourced according to
3797 filename extension, falling back to GDB scripts if the first
3799 If set to "strict", files are sourced according to filename extension.
3801 set ada trust-PAD-over-XVS on|off
3802 show ada trust-PAD-over-XVS
3803 If off, activate a workaround against a bug in the debugging information
3804 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3805 the GCC sources for more information about the GNAT encoding and
3806 PAD types in particular). It is always safe to set this option to
3807 off, but this introduces a slight performance penalty. The default
3810 * Python API Improvements
3812 ** GDB provides the new class gdb.LazyString. This is useful in
3813 some pretty-printing cases. The new method gdb.Value.lazy_string
3814 provides a simple way to create objects of this type.
3816 ** The fields returned by gdb.Type.fields now have an
3817 `is_base_class' attribute.
3819 ** The new method gdb.Type.range returns the range of an array type.
3821 ** The new method gdb.parse_and_eval can be used to parse and
3822 evaluate an expression.
3824 * New remote packets
3827 Define a trace state variable.
3830 Get the current value of a trace state variable.
3833 Set desired tracing behavior upon disconnection.
3836 Set the trace buffer to be linear or circular.
3839 Get data about the tracepoints currently in use.
3843 Process record now works correctly with hardware watchpoints.
3845 Multiple bug fixes have been made to the mips-irix port, making it
3846 much more reliable. In particular:
3847 - Debugging threaded applications is now possible again. Previously,
3848 GDB would hang while starting the program, or while waiting for
3849 the program to stop at a breakpoint.
3850 - Attaching to a running process no longer hangs.
3851 - An error occurring while loading a core file has been fixed.
3852 - Changing the value of the PC register now works again. This fixes
3853 problems observed when using the "jump" command, or when calling
3854 a function from GDB, or even when assigning a new value to $pc.
3855 - With the "finish" and "return" commands, the return value for functions
3856 returning a small array is now correctly printed.
3857 - It is now possible to break on shared library code which gets executed
3858 during a shared library init phase (code executed while executing
3859 their .init section). Previously, the breakpoint would have no effect.
3860 - GDB is now able to backtrace through the signal handler for
3861 non-threaded programs.
3863 PIE (Position Independent Executable) programs debugging is now supported.
3864 This includes debugging execution of PIC (Position Independent Code) shared
3865 libraries although for that, it should be possible to run such libraries as an
3868 *** Changes in GDB 7.0
3870 * GDB now has an interface for JIT compilation. Applications that
3871 dynamically generate code can create symbol files in memory and register
3872 them with GDB. For users, the feature should work transparently, and
3873 for JIT developers, the interface is documented in the GDB manual in the
3874 "JIT Compilation Interface" chapter.
3876 * Tracepoints may now be conditional. The syntax is as for
3877 breakpoints; either an "if" clause appended to the "trace" command,
3878 or the "condition" command is available. GDB sends the condition to
3879 the target for evaluation using the same bytecode format as is used
3880 for tracepoint actions.
3882 * The disassemble command now supports: an optional /r modifier, print the
3883 raw instructions in hex as well as in symbolic form, and an optional /m
3884 modifier to print mixed source+assembly.
3886 * Process record and replay
3888 In a architecture environment that supports ``process record and
3889 replay'', ``process record and replay'' target can record a log of
3890 the process execution, and replay it with both forward and reverse
3893 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3894 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3895 set execution-direction {forward|reverse}, for targets that support
3898 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3899 feature is available with a native GDB running on kernel version
3902 * GDB now has support for multi-byte and wide character sets on the
3903 target. Strings whose character type is wchar_t, char16_t, or
3904 char32_t are now correctly printed. GDB supports wide- and unicode-
3905 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3906 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3907 `printf'. This feature requires iconv to work properly; if your
3908 system does not have a working iconv, GDB can use GNU libiconv. See
3909 the installation instructions for more information.
3911 * GDB now supports automatic retrieval of shared library files from
3912 remote targets. To use this feature, specify a system root that begins
3913 with the `remote:' prefix, either via the `set sysroot' command or via
3914 the `--with-sysroot' configure-time option.
3916 * "info sharedlibrary" now takes an optional regex of libraries to show,
3917 and it now reports if a shared library has no debugging information.
3919 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3920 now complete on file names.
3922 * When completing in expressions, gdb will attempt to limit
3923 completions to allowable structure or union fields, where appropriate.
3924 For instance, consider:
3926 # struct example { int f1; double f2; };
3927 # struct example variable;
3930 If the user types TAB at the end of this command line, the available
3931 completions will be "f1" and "f2".
3933 * Inlined functions are now supported. They show up in backtraces, and
3934 the "step", "next", and "finish" commands handle them automatically.
3936 * GDB now supports the token-splicing (##) and stringification (#)
3937 operators when expanding macros. It also supports variable-arity
3940 * GDB now supports inspecting extra signal information, exported by
3941 the new $_siginfo convenience variable. The feature is currently
3942 implemented on linux ARM, i386 and amd64.
3944 * GDB can now display the VFP floating point registers and NEON vector
3945 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3946 can provide these registers (requires Linux 2.6.30 or later). Remote
3947 and simulator targets may also provide them.
3949 * New remote packets
3952 Search memory for a sequence of bytes.
3955 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3956 operation over reliable transport links. Use of this packet is
3957 controlled by the `set remote noack-packet' command.
3960 Kill the process with the specified process ID. Use this in preference
3961 to `k' when multiprocess protocol extensions are supported.
3964 Obtains additional operating system information
3968 Read or write additional signal information.
3970 * Removed remote protocol undocumented extension
3972 An undocumented extension to the remote protocol's `S' stop reply
3973 packet that permited the stub to pass a process id was removed.
3974 Remote servers should use the `T' stop reply packet instead.
3976 * GDB now supports multiple function calling conventions according to the
3977 DWARF-2 DW_AT_calling_convention function attribute.
3979 * The SH target utilizes the aforementioned change to distinguish between gcc
3980 and Renesas calling convention. It also adds the new CLI commands
3981 `set/show sh calling-convention'.
3983 * GDB can now read compressed debug sections, as produced by GNU gold
3984 with the --compress-debug-sections=zlib flag.
3986 * 64-bit core files are now supported on AIX.
3988 * Thread switching is now supported on Tru64.
3990 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3991 which will be allocated using malloc later in program execution.
3993 * The qXfer:libraries:read remote procotol packet now allows passing a
3994 list of section offsets.
3996 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3997 conditions handling signals delivered during attach or thread creation
3998 have also been fixed.
4000 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4001 From the user's standpoint, all unqualified instances of True and False
4002 are treated as the standard definitions, regardless of context.
4004 * GDB now parses C++ symbol and type names more flexibly. For
4007 template<typename T> class C { };
4010 GDB will now correctly handle all of:
4012 ptype C<char const *>
4013 ptype C<char const*>
4014 ptype C<const char *>
4015 ptype C<const char*>
4017 * New features in the GDB remote stub, gdbserver
4019 - The "--wrapper" command-line argument tells gdbserver to use a
4020 wrapper program to launch programs for debugging.
4022 - On PowerPC and S/390 targets, it is now possible to use a single
4023 gdbserver executable to debug both 32-bit and 64-bit programs.
4024 (This requires gdbserver itself to be built as a 64-bit executable.)
4026 - gdbserver uses the new noack protocol mode for TCP connections to
4027 reduce communications latency, if also supported and enabled in GDB.
4029 - Support for the sparc64-linux-gnu target is now included in
4032 - The amd64-linux build of gdbserver now supports debugging both
4033 32-bit and 64-bit programs.
4035 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4036 now support hardware watchpoints, and will use them automatically
4041 GDB now has support for scripting using Python. Whether this is
4042 available is determined at configure time.
4044 New GDB commands can now be written in Python.
4046 * Ada tasking support
4048 Ada tasks can now be inspected in GDB. The following commands have
4052 Print the list of Ada tasks.
4054 Print detailed information about task number N.
4056 Print the task number of the current task.
4058 Switch the context of debugging to task number N.
4060 * Support for user-defined prefixed commands. The "define" command can
4061 add new commands to existing prefixes, e.g. "target".
4063 * Multi-inferior, multi-process debugging.
4065 GDB now has generalized support for multi-inferior debugging. See
4066 "Debugging Multiple Inferiors" in the manual for more information.
4067 Although availability still depends on target support, the command
4068 set is more uniform now. The GNU/Linux specific multi-forks support
4069 has been migrated to this new framework. This implied some user
4070 visible changes; see "New commands" and also "Removed commands"
4073 * Target descriptions can now describe the target OS ABI. See the
4074 "Target Description Format" section in the user manual for more
4077 * Target descriptions can now describe "compatible" architectures
4078 to indicate that the target can execute applications for a different
4079 architecture in addition to those for the main target architecture.
4080 See the "Target Description Format" section in the user manual for
4083 * Multi-architecture debugging.
4085 GDB now includes general supports for debugging applications on
4086 hybrid systems that use more than one single processor architecture
4087 at the same time. Each such hybrid architecture still requires
4088 specific support to be added. The only hybrid architecture supported
4089 in this version of GDB is the Cell Broadband Engine.
4091 * GDB now supports integrated debugging of Cell/B.E. applications that
4092 use both the PPU and SPU architectures. To enable support for hybrid
4093 Cell/B.E. debugging, you need to configure GDB to support both the
4094 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4095 --enable-targets configure option.
4097 * Non-stop mode debugging.
4099 For some targets, GDB now supports an optional mode of operation in
4100 which you can examine stopped threads while other threads continue
4101 to execute freely. This is referred to as non-stop mode, with the
4102 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4103 section in the user manual for more information.
4105 To be able to support remote non-stop debugging, a remote stub needs
4106 to implement the non-stop mode remote protocol extensions, as
4107 described in the "Remote Non-Stop" section of the user manual. The
4108 GDB remote stub, gdbserver, has been adjusted to support these
4109 extensions on linux targets.
4111 * New commands (for set/show, see "New options" below)
4113 catch syscall [NAME(S) | NUMBER(S)]
4114 Catch system calls. Arguments, which should be names of system
4115 calls or their numbers, mean catch only those syscalls. Without
4116 arguments, every syscall will be caught. When the inferior issues
4117 any of the specified syscalls, GDB will stop and announce the system
4118 call, both when it is called and when its call returns. This
4119 feature is currently available with a native GDB running on the
4120 Linux Kernel, under the following architectures: x86, x86_64,
4121 PowerPC and PowerPC64.
4123 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4125 Search memory for a sequence of bytes.
4127 maint set python print-stack
4128 maint show python print-stack
4129 Show a stack trace when an error is encountered in a Python script.
4132 Invoke CODE by passing it to the Python interpreter.
4137 These allow macros to be defined, undefined, and listed
4141 Show operating system information about processes.
4144 List the inferiors currently under GDB's control.
4147 Switch focus to inferior number NUM.
4150 Detach from inferior number NUM.
4153 Kill inferior number NUM.
4157 set spu stop-on-load
4158 show spu stop-on-load
4159 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4161 set spu auto-flush-cache
4162 show spu auto-flush-cache
4163 Control whether to automatically flush the software-managed cache
4164 during Cell/B.E. debugging.
4166 set sh calling-convention
4167 show sh calling-convention
4168 Control the calling convention used when calling SH target functions.
4171 show debug timestamp
4172 Control display of timestamps with GDB debugging output.
4174 set disassemble-next-line
4175 show disassemble-next-line
4176 Control display of disassembled source lines or instructions when
4179 set remote noack-packet
4180 show remote noack-packet
4181 Set/show the use of remote protocol QStartNoAckMode packet. See above
4182 under "New remote packets."
4184 set remote query-attached-packet
4185 show remote query-attached-packet
4186 Control use of remote protocol `qAttached' (query-attached) packet.
4188 set remote read-siginfo-object
4189 show remote read-siginfo-object
4190 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4193 set remote write-siginfo-object
4194 show remote write-siginfo-object
4195 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4198 set remote reverse-continue
4199 show remote reverse-continue
4200 Control use of remote protocol 'bc' (reverse-continue) packet.
4202 set remote reverse-step
4203 show remote reverse-step
4204 Control use of remote protocol 'bs' (reverse-step) packet.
4206 set displaced-stepping
4207 show displaced-stepping
4208 Control displaced stepping mode. Displaced stepping is a way to
4209 single-step over breakpoints without removing them from the debuggee.
4210 Also known as "out-of-line single-stepping".
4213 show debug displaced
4214 Control display of debugging info for displaced stepping.
4216 maint set internal-error
4217 maint show internal-error
4218 Control what GDB does when an internal error is detected.
4220 maint set internal-warning
4221 maint show internal-warning
4222 Control what GDB does when an internal warning is detected.
4227 Use a wrapper program to launch programs for debugging.
4229 set multiple-symbols (all|ask|cancel)
4230 show multiple-symbols
4231 The value of this variable can be changed to adjust the debugger behavior
4232 when an expression or a breakpoint location contains an ambiguous symbol
4233 name (an overloaded function name, for instance).
4235 set breakpoint always-inserted
4236 show breakpoint always-inserted
4237 Keep breakpoints always inserted in the target, as opposed to inserting
4238 them when resuming the target, and removing them when the target stops.
4239 This option can improve debugger performance on slow remote targets.
4241 set arm fallback-mode (arm|thumb|auto)
4242 show arm fallback-mode
4243 set arm force-mode (arm|thumb|auto)
4245 These commands control how ARM GDB determines whether instructions
4246 are ARM or Thumb. The default for both settings is auto, which uses
4247 the current CPSR value for instructions without symbols; previous
4248 versions of GDB behaved as if "set arm fallback-mode arm".
4250 set disable-randomization
4251 show disable-randomization
4252 Standalone programs run with the virtual address space randomization enabled
4253 by default on some platforms. This option keeps the addresses stable across
4254 multiple debugging sessions.
4258 Control whether other threads are stopped or not when some thread hits
4263 Requests that asynchronous execution is enabled in the target, if available.
4264 In this case, it's possible to resume target in the background, and interact
4265 with GDB while the target is running. "show target-async" displays the
4266 current state of asynchronous execution of the target.
4268 set target-wide-charset
4269 show target-wide-charset
4270 The target-wide-charset is the name of the character set that GDB
4271 uses when printing characters whose type is wchar_t.
4273 set tcp auto-retry (on|off)
4275 set tcp connect-timeout
4276 show tcp connect-timeout
4277 These commands allow GDB to retry failed TCP connections to a remote stub
4278 with a specified timeout period; this is useful if the stub is launched
4279 in parallel with GDB but may not be ready to accept connections immediately.
4281 set libthread-db-search-path
4282 show libthread-db-search-path
4283 Control list of directories which GDB will search for appropriate
4286 set schedule-multiple (on|off)
4287 show schedule-multiple
4288 Allow GDB to resume all threads of all processes or only threads of
4289 the current process.
4293 Use more aggressive caching for accesses to the stack. This improves
4294 performance of remote debugging (particularly backtraces) without
4295 affecting correctness.
4297 set interactive-mode (on|off|auto)
4298 show interactive-mode
4299 Control whether GDB runs in interactive mode (on) or not (off).
4300 When in interactive mode, GDB waits for the user to answer all
4301 queries. Otherwise, GDB does not wait and assumes the default
4302 answer. When set to auto (the default), GDB determines which
4303 mode to use based on the stdin settings.
4308 For program forks, this is replaced by the new more generic `info
4309 inferiors' command. To list checkpoints, you can still use the
4310 `info checkpoints' command, which was an alias for the `info forks'
4314 Replaced by the new `inferior' command. To switch between
4315 checkpoints, you can still use the `restart' command, which was an
4316 alias for the `fork' command.
4319 This is removed, since some targets don't have a notion of
4320 processes. To switch between processes, you can still use the
4321 `inferior' command using GDB's own inferior number.
4324 For program forks, this is replaced by the new more generic `kill
4325 inferior' command. To delete a checkpoint, you can still use the
4326 `delete checkpoint' command, which was an alias for the `delete
4330 For program forks, this is replaced by the new more generic `detach
4331 inferior' command. To detach a checkpoint, you can still use the
4332 `detach checkpoint' command, which was an alias for the `detach
4335 * New native configurations
4337 x86/x86_64 Darwin i[34567]86-*-darwin*
4339 x86_64 MinGW x86_64-*-mingw*
4343 Lattice Mico32 lm32-*
4344 x86 DICOS i[34567]86-*-dicos*
4345 x86_64 DICOS x86_64-*-dicos*
4348 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4349 (mingw32ce) debugging.
4355 These commands were actually not implemented on any target.
4357 *** Changes in GDB 6.8
4359 * New native configurations
4361 NetBSD/hppa hppa*-*netbsd*
4362 Xtensa GNU/Linux xtensa*-*-linux*
4366 NetBSD/hppa hppa*-*-netbsd*
4367 Xtensa GNU/Lunux xtensa*-*-linux*
4369 * Change in command line behavior -- corefiles vs. process ids.
4371 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4372 attaching to process NUMBER fails, GDB no longer attempts to open a
4373 core file named NUMBER. Attaching to a program using the -c option
4374 is no longer supported. Instead, use the '-p' or '--pid' options.
4376 * GDB can now be built as a native debugger for debugging Windows x86
4377 (mingw32) Portable Executable (PE) programs.
4379 * Pending breakpoints no longer change their number when their address
4382 * GDB now supports breakpoints with multiple locations,
4383 including breakpoints on C++ constructors, inside C++ templates,
4384 and in inlined functions.
4386 * GDB's ability to debug optimized code has been improved. GDB more
4387 accurately identifies function bodies and lexical blocks that occupy
4388 more than one contiguous range of addresses.
4390 * Target descriptions can now describe registers for PowerPC.
4392 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4393 registers on PowerPC targets.
4395 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4396 targets even when the libthread_db library is not available.
4398 * The GDB remote stub, gdbserver, now supports the new file transfer
4399 commands (remote put, remote get, and remote delete).
4401 * The GDB remote stub, gdbserver, now supports run and attach in
4402 extended-remote mode.
4404 * hppa*64*-*-hpux11* target broken
4405 The debugger is unable to start a program and fails with the following
4406 error: "Error trying to get information about dynamic linker".
4407 The gdb-6.7 release is also affected.
4409 * GDB now supports the --enable-targets= configure option to allow
4410 building a single GDB executable that supports multiple remote
4411 target architectures.
4413 * GDB now supports debugging C and C++ programs which use the
4414 Decimal Floating Point extension. In addition, the PowerPC target
4415 now has a set of pseudo-registers to inspect decimal float values
4416 stored in two consecutive float registers.
4418 * The -break-insert MI command can optionally create pending
4421 * Improved support for debugging Ada
4422 Many improvements to the Ada language support have been made. These
4424 - Better support for Ada2005 interface types
4425 - Improved handling of arrays and slices in general
4426 - Better support for Taft-amendment types
4427 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4429 - Improved command completion in Ada
4432 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4437 set print frame-arguments (all|scalars|none)
4438 show print frame-arguments
4439 The value of this variable can be changed to control which argument
4440 values should be printed by the debugger when displaying a frame.
4445 Transfer files to and from a remote target, and delete remote files.
4452 Transfer files to and from a remote target, and delete remote files.
4454 * New remote packets
4461 Open, close, read, write, and delete files on the remote system.
4464 Attach to an existing process on the remote system, in extended-remote
4468 Run a new process on the remote system, in extended-remote mode.
4470 *** Changes in GDB 6.7
4472 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4473 bfd, libiberty and opcodes, as revealed by static analysis donated by
4474 Coverity, Inc. (http://scan.coverity.com).
4476 * When looking up multiply-defined global symbols, GDB will now prefer the
4477 symbol definition in the current shared library if it was built using the
4478 -Bsymbolic linker option.
4480 * When the Text User Interface (TUI) is not configured, GDB will now
4481 recognize the -tui command-line option and print a message that the TUI
4484 * The GDB remote stub, gdbserver, now has lower overhead for high
4485 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4487 * GDB for MIPS targets now autodetects whether a remote target provides
4488 32-bit or 64-bit register values.
4490 * Support for C++ member pointers has been improved.
4492 * GDB now understands XML target descriptions, which specify the
4493 target's overall architecture. GDB can read a description from
4494 a local file or over the remote serial protocol.
4496 * Vectors of single-byte data use a new integer type which is not
4497 automatically displayed as character or string data.
4499 * The /s format now works with the print command. It displays
4500 arrays of single-byte integers and pointers to single-byte integers
4503 * Target descriptions can now describe target-specific registers,
4504 for architectures which have implemented the support (currently
4505 only ARM, M68K, and MIPS).
4507 * GDB and the GDB remote stub, gdbserver, now support the XScale
4510 * The GDB remote stub, gdbserver, has been updated to support
4511 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4512 has been rewritten to use the standard GDB remote protocol.
4514 * GDB can now step into C++ functions which are called through thunks.
4516 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4518 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4519 layout. It also supports a TextSeg= and DataSeg= response when only
4520 segment base addresses (rather than offsets) are available.
4522 * The /i format now outputs any trailing branch delay slot instructions
4523 immediately following the last instruction within the count specified.
4525 * The GDB remote protocol "T" stop reply packet now supports a
4526 "library" response. Combined with the new "qXfer:libraries:read"
4527 packet, this response allows GDB to debug shared libraries on targets
4528 where the operating system manages the list of loaded libraries (e.g.
4529 Windows and SymbianOS).
4531 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4532 (DLLs) on Windows and Windows CE targets.
4534 * GDB now supports a faster verification that a .debug file matches its binary
4535 according to its build-id signature, if the signature is present.
4541 Enable or disable hardware flow control (RTS/CTS) on the serial port
4542 when debugging using remote targets.
4544 set mem inaccessible-by-default
4545 show mem inaccessible-by-default
4546 If the target supplies a memory map, for instance via the remote
4547 protocol's "qXfer:memory-map:read" packet, setting this variable
4548 prevents GDB from accessing memory outside the memory map. This
4549 is useful for targets with memory mapped registers or which react
4550 badly to accesses of unmapped address space.
4552 set breakpoint auto-hw
4553 show breakpoint auto-hw
4554 If the target supplies a memory map, for instance via the remote
4555 protocol's "qXfer:memory-map:read" packet, setting this variable
4556 lets GDB use hardware breakpoints automatically for memory regions
4557 where it can not use software breakpoints. This covers both the
4558 "break" command and internal breakpoints used for other commands
4559 including "next" and "finish".
4562 catch exception unhandled
4563 Stop the program execution when Ada exceptions are raised.
4566 Stop the program execution when an Ada assertion failed.
4570 Set an alternate system root for target files. This is a more
4571 general version of "set solib-absolute-prefix", which is now
4572 an alias to "set sysroot".
4575 Provide extended SPU facility status information. This set of
4576 commands is available only when debugging the Cell/B.E. SPU
4579 * New native configurations
4581 OpenBSD/sh sh*-*openbsd*
4584 unset tdesc filename
4586 Use the specified local file as an XML target description, and do
4587 not query the target for its built-in description.
4591 OpenBSD/sh sh*-*-openbsd*
4592 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4593 Toshiba Media Processor mep-elf
4595 * New remote packets
4598 Ignore the specified signals; pass them directly to the debugged program
4599 without stopping other threads or reporting them to GDB.
4601 qXfer:features:read:
4602 Read an XML target description from the target, which describes its
4607 Read or write contents of an spufs file on the target system. These
4608 packets are available only on the Cell/B.E. SPU architecture.
4610 qXfer:libraries:read:
4611 Report the loaded shared libraries. Combined with new "T" packet
4612 response, this packet allows GDB to debug shared libraries on
4613 targets where the operating system manages the list of loaded
4614 libraries (e.g. Windows and SymbianOS).
4618 Support for these obsolete configurations has been removed.
4626 i[34567]86-*-lynxos*
4627 i[34567]86-*-netware*
4628 i[34567]86-*-sco3.2v5*
4629 i[34567]86-*-sco3.2v4*
4631 i[34567]86-*-sysv4.2*
4634 i[34567]86-*-unixware2*
4635 i[34567]86-*-unixware*
4644 * Other removed features
4651 Various m68k-only ROM monitors.
4658 Various Renesas ROM monitors and debugging interfaces for SH and
4663 Support for a Macraigor serial interface to on-chip debugging.
4664 GDB does not directly support the newer parallel or USB
4669 A debug information format. The predecessor to DWARF 2 and
4670 DWARF 3, which are still supported.
4672 Support for the HP aCC compiler on HP-UX/PA-RISC
4674 SOM-encapsulated symbolic debugging information, automatic
4675 invocation of pxdb, and the aCC custom C++ ABI. This does not
4676 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4677 with aCC can still be debugged on an assembly level.
4679 MIPS ".pdr" sections
4681 A MIPS-specific format used to describe stack frame layout
4682 in debugging information.
4686 GDB could work with an older version of Guile to debug
4687 the interpreter and Scheme programs running in it.
4689 set mips stack-arg-size
4690 set mips saved-gpreg-size
4692 Use "set mips abi" to control parameter passing for MIPS.
4694 *** Changes in GDB 6.6
4699 Cell Broadband Engine SPU spu-elf
4701 * GDB can now be configured as a cross-debugger targeting native Windows
4702 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4703 running on a Windows system over TCP/IP to debug Windows programs.
4705 * The GDB remote stub, gdbserver, has been updated to support Windows and
4706 Cygwin debugging. Both single-threaded and multi-threaded programs are
4709 * The "set trust-readonly-sections" command works again. This command was
4710 broken in GDB 6.3, 6.4, and 6.5.
4712 * The "load" command now supports writing to flash memory, if the remote
4713 stub provides the required support.
4715 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4716 longer requires symbolic debug information (e.g. DWARF-2).
4721 unset substitute-path
4722 show substitute-path
4723 Manage a list of substitution rules that GDB uses to rewrite the name
4724 of the directories where the sources are located. This can be useful
4725 for instance when the sources were moved to a different location
4726 between compilation and debugging.
4730 Print each CLI command as it is executed. Each command is prefixed with
4731 a number of `+' symbols representing the nesting depth.
4732 The source command now has a `-v' option to enable the same feature.
4736 The ARM Demon monitor support (RDP protocol, "target rdp").
4738 Kernel Object Display, an embedded debugging feature which only worked with
4739 an obsolete version of Cisco IOS.
4741 The 'set download-write-size' and 'show download-write-size' commands.
4743 * New remote packets
4746 Tell a stub about GDB client features, and request remote target features.
4747 The first feature implemented is PacketSize, which allows the target to
4748 specify the size of packets it can handle - to minimize the number of
4749 packets required and improve performance when connected to a remote
4753 Fetch an OS auxilliary vector from the remote stub. This packet is a
4754 more efficient replacement for qPart:auxv:read.
4756 qXfer:memory-map:read:
4757 Fetch a memory map from the remote stub, including information about
4758 RAM, ROM, and flash memory devices.
4763 Erase and program a flash memory device.
4765 * Removed remote packets
4768 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4769 used it, and only gdbserver implemented it.
4771 *** Changes in GDB 6.5
4775 Renesas M32C/M16C m32c-elf
4777 Morpho Technologies ms1 ms1-elf
4781 init-if-undefined Initialize a convenience variable, but
4782 only if it doesn't already have a value.
4784 The following commands are presently only implemented for native GNU/Linux:
4786 checkpoint Save a snapshot of the program state.
4788 restart <n> Return the program state to a
4789 previously saved state.
4791 info checkpoints List currently saved checkpoints.
4793 delete-checkpoint <n> Delete a previously saved checkpoint.
4795 set|show detach-on-fork Tell gdb whether to detach from a newly
4796 forked process, or to keep debugging it.
4798 info forks List forks of the user program that
4799 are available to be debugged.
4801 fork <n> Switch to debugging one of several
4802 forks of the user program that are
4803 available to be debugged.
4805 delete-fork <n> Delete a fork from the list of forks
4806 that are available to be debugged (and
4807 kill the forked process).
4809 detach-fork <n> Delete a fork from the list of forks
4810 that are available to be debugged (and
4811 allow the process to continue).
4815 Morpho Technologies ms2 ms1-elf
4817 * Improved Windows host support
4819 GDB now builds as a cross debugger hosted on i686-mingw32, including
4820 native console support, and remote communications using either
4821 network sockets or serial ports.
4823 * Improved Modula-2 language support
4825 GDB can now print most types in the Modula-2 syntax. This includes:
4826 basic types, set types, record types, enumerated types, range types,
4827 pointer types and ARRAY types. Procedure var parameters are correctly
4828 printed and hexadecimal addresses and character constants are also
4829 written in the Modula-2 syntax. Best results can be obtained by using
4830 GNU Modula-2 together with the -gdwarf-2 command line option.
4834 The ARM rdi-share module.
4836 The Netware NLM debug server.
4838 *** Changes in GDB 6.4
4840 * New native configurations
4842 OpenBSD/arm arm*-*-openbsd*
4843 OpenBSD/mips64 mips64-*-openbsd*
4847 Morpho Technologies ms1 ms1-elf
4849 * New command line options
4851 --batch-silent As for --batch, but totally silent.
4852 --return-child-result The debugger will exist with the same value
4853 the child (debugged) program exited with.
4854 --eval-command COMMAND, -ex COMMAND
4855 Execute a single GDB CLI command. This may be
4856 specified multiple times and in conjunction
4857 with the --command (-x) option.
4859 * Deprecated commands removed
4861 The following commands, that were deprecated in 2000, have been
4865 set|show arm disassembly-flavor set|show arm disassembler
4866 othernames set arm disassembler
4867 set|show remotedebug set|show debug remote
4868 set|show archdebug set|show debug arch
4869 set|show eventdebug set|show debug event
4872 * New BSD user-level threads support
4874 It is now possible to debug programs using the user-level threads
4875 library on OpenBSD and FreeBSD. Currently supported (target)
4878 FreeBSD/amd64 x86_64-*-freebsd*
4879 FreeBSD/i386 i386-*-freebsd*
4880 OpenBSD/i386 i386-*-openbsd*
4882 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4883 are not yet supported.
4885 * New support for Matsushita MN10300 w/sim added
4886 (Work in progress). mn10300-elf.
4888 * REMOVED configurations and files
4890 VxWorks and the XDR protocol *-*-vxworks
4891 Motorola MCORE mcore-*-*
4892 National Semiconductor NS32000 ns32k-*-*
4894 * New "set print array-indexes" command
4896 After turning this setting "on", GDB prints the index of each element
4897 when displaying arrays. The default is "off" to preserve the previous
4900 * VAX floating point support
4902 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4904 * User-defined command support
4906 In addition to using $arg0..$arg9 for argument passing, it is now possible
4907 to use $argc to determine now many arguments have been passed. See the
4908 section on user-defined commands in the user manual for more information.
4910 *** Changes in GDB 6.3:
4912 * New command line option
4914 GDB now accepts -l followed by a number to set the timeout for remote
4917 * GDB works with GCC -feliminate-dwarf2-dups
4919 GDB now supports a more compact representation of DWARF-2 debug
4920 information using DW_FORM_ref_addr references. These are produced
4921 by GCC with the option -feliminate-dwarf2-dups and also by some
4922 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4923 to use -feliminate-dwarf2-dups.
4925 * Internationalization
4927 When supported by the host system, GDB will be built with
4928 internationalization (libintl). The task of marking up the sources is
4929 continued, we're looking forward to our first translation.
4933 Initial support for debugging programs compiled with the GNAT
4934 implementation of the Ada programming language has been integrated
4935 into GDB. In this release, support is limited to expression evaluation.
4937 * New native configurations
4939 GNU/Linux/m32r m32r-*-linux-gnu
4943 GDB's remote protocol now includes support for the 'p' packet. This
4944 packet is used to fetch individual registers from a remote inferior.
4946 * END-OF-LIFE registers[] compatibility module
4948 GDB's internal register infrastructure has been completely rewritten.
4949 The new infrastructure making possible the implementation of key new
4950 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4953 GDB 6.3 will be the last release to include the the registers[]
4954 compatibility module that allowed out-of-date configurations to
4955 continue to work. This change directly impacts the following
4965 powerpc bdm protocol
4967 Unless there is activity to revive these configurations, they will be
4968 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4970 * OBSOLETE configurations and files
4972 Configurations that have been declared obsolete in this release have
4973 been commented out. Unless there is activity to revive these
4974 configurations, the next release of GDB will have their sources
4975 permanently REMOVED.
4984 *** Changes in GDB 6.2.1:
4986 * MIPS `break main; run' gave an heuristic-fence-post warning
4988 When attempting to run even a simple program, a warning about
4989 heuristic-fence-post being hit would be reported. This problem has
4992 * MIPS IRIX 'long double' crashed GDB
4994 When examining a long double variable, GDB would get a segmentation
4995 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4996 IRIX long double values).
5000 A bug in the VAX stack code was causing problems with the "next"
5001 command. This problem has been fixed.
5003 *** Changes in GDB 6.2:
5005 * Fix for ``many threads''
5007 On GNU/Linux systems that use the NPTL threads library, a program
5008 rapidly creating and deleting threads would confuse GDB leading to the
5011 ptrace: No such process.
5012 thread_db_get_info: cannot get thread info: generic error
5014 This problem has been fixed.
5016 * "-async" and "-noasync" options removed.
5018 Support for the broken "-noasync" option has been removed (it caused
5021 * New ``start'' command.
5023 This command runs the program until the begining of the main procedure.
5025 * New BSD Kernel Data Access Library (libkvm) interface
5027 Using ``target kvm'' it is now possible to debug kernel core dumps and
5028 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5029 platforms. Currently supported (native-only) configurations are:
5031 FreeBSD/amd64 x86_64-*-freebsd*
5032 FreeBSD/i386 i?86-*-freebsd*
5033 NetBSD/i386 i?86-*-netbsd*
5034 NetBSD/m68k m68*-*-netbsd*
5035 NetBSD/sparc sparc-*-netbsd*
5036 OpenBSD/amd64 x86_64-*-openbsd*
5037 OpenBSD/i386 i?86-*-openbsd*
5038 OpenBSD/m68k m68*-openbsd*
5039 OpenBSD/sparc sparc-*-openbsd*
5041 * Signal trampoline code overhauled
5043 Many generic problems with GDB's signal handling code have been fixed.
5044 These include: backtraces through non-contiguous stacks; recognition
5045 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5046 call; backtrace through a signal trampoline; step into and out of
5047 signal handlers; and single-stepping in the signal trampoline.
5049 Please note that kernel bugs are a limiting factor here. These
5050 features have been shown to work on an s390 GNU/Linux system that
5051 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5053 * Cygwin support for DWARF 2 added.
5055 * New native configurations
5057 GNU/Linux/hppa hppa*-*-linux*
5058 OpenBSD/hppa hppa*-*-openbsd*
5059 OpenBSD/m68k m68*-*-openbsd*
5060 OpenBSD/m88k m88*-*-openbsd*
5061 OpenBSD/powerpc powerpc-*-openbsd*
5062 NetBSD/vax vax-*-netbsd*
5063 OpenBSD/vax vax-*-openbsd*
5065 * END-OF-LIFE frame compatibility module
5067 GDB's internal frame infrastructure has been completely rewritten.
5068 The new infrastructure making it possible to support key new features
5069 including DWARF 2 Call Frame Information. To aid in the task of
5070 migrating old configurations to this new infrastructure, a
5071 compatibility module, that allowed old configurations to continue to
5072 work, was also included.
5074 GDB 6.2 will be the last release to include this frame compatibility
5075 module. This change directly impacts the following configurations:
5085 Unless there is activity to revive these configurations, they will be
5086 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5088 * REMOVED configurations and files
5090 Sun 3, running SunOS 3 m68*-*-sunos3*
5091 Sun 3, running SunOS 4 m68*-*-sunos4*
5092 Sun 2, running SunOS 3 m68000-*-sunos3*
5093 Sun 2, running SunOS 4 m68000-*-sunos4*
5094 Motorola 680x0 running LynxOS m68*-*-lynxos*
5095 AT&T 3b1/Unix pc m68*-att-*
5096 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5097 decstation mips-dec-* mips-little-*
5098 riscos mips-*-riscos* mips-*-sysv*
5099 sonymips mips-sony-*
5100 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5102 *** Changes in GDB 6.1.1:
5104 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5106 The TUI (Text-mode User Interface) is now built as part of a default
5107 GDB configuration. It is enabled by either selecting the TUI with the
5108 command line option "-i=tui" or by running the separate "gdbtui"
5109 program. For more information on the TUI, see the manual "Debugging
5112 * Pending breakpoint support (also included in GDB 6.1)
5114 Support has been added to allow you to specify breakpoints in shared
5115 libraries that have not yet been loaded. If a breakpoint location
5116 cannot be found, and the "breakpoint pending" option is set to auto,
5117 GDB queries you if you wish to make the breakpoint pending on a future
5118 shared-library load. If and when GDB resolves the breakpoint symbol,
5119 the pending breakpoint is removed as one or more regular breakpoints
5122 Pending breakpoints are very useful for GCJ Java debugging.
5124 * Fixed ISO-C build problems
5126 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5127 non ISO-C code that stopped them being built using a more strict ISO-C
5128 compiler (e.g., IBM's C compiler).
5130 * Fixed build problem on IRIX 5
5132 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5133 wasn't able to compile compile on an IRIX 5 system.
5135 * Added execute permission to gdb/gdbserver/configure
5137 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5138 permission. This bug would cause configure to fail on a number of
5139 systems (Solaris, IRIX). Ref: server/519.
5141 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5143 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5144 has been updated to use constant array sizes.
5146 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5148 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5149 its generated DWARF Call Frame Info. This encoding was causing GDB to
5150 panic, that panic has been fixed. Ref: gdb/1628.
5152 * Fixed a problem when examining parameters in shared library code.
5154 When examining parameters in optimized shared library code generated
5155 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5156 not available''. GDB now correctly displays the variable's value.
5158 *** Changes in GDB 6.1:
5160 * Removed --with-mmalloc
5162 Support for the mmalloc memory manager has been removed, as it
5163 conflicted with the internal gdb byte cache.
5165 * Changes in AMD64 configurations
5167 The AMD64 target now includes the %cs and %ss registers. As a result
5168 the AMD64 remote protocol has changed; this affects the floating-point
5169 and SSE registers. If you rely on those registers for your debugging,
5170 you should upgrade gdbserver on the remote side.
5172 * Revised SPARC target
5174 The SPARC target has been completely revised, incorporating the
5175 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5176 support for LynxOS and SunOS 4 has been dropped. Calling functions
5177 from within GDB on operating systems with a non-executable stack
5178 (Solaris, OpenBSD) now works.
5182 GDB has a new C++ demangler which does a better job on the mangled
5183 names generated by current versions of g++. It also runs faster, so
5184 with this and other changes gdb should now start faster on large C++
5187 * DWARF 2 Location Expressions
5189 GDB support for location expressions has been extended to support function
5190 arguments and frame bases. Older versions of GDB could crash when they
5193 * C++ nested types and namespaces
5195 GDB's support for nested types and namespaces in C++ has been
5196 improved, especially if you use the DWARF 2 debugging format. (This
5197 is the default for recent versions of GCC on most platforms.)
5198 Specifically, if you have a class "Inner" defined within a class or
5199 namespace "Outer", then GDB realizes that the class's name is
5200 "Outer::Inner", not simply "Inner". This should greatly reduce the
5201 frequency of complaints about not finding RTTI symbols. In addition,
5202 if you are stopped at inside of a function defined within a namespace,
5203 GDB modifies its name lookup accordingly.
5205 * New native configurations
5207 NetBSD/amd64 x86_64-*-netbsd*
5208 OpenBSD/amd64 x86_64-*-openbsd*
5209 OpenBSD/alpha alpha*-*-openbsd*
5210 OpenBSD/sparc sparc-*-openbsd*
5211 OpenBSD/sparc64 sparc64-*-openbsd*
5213 * New debugging protocols
5215 M32R with SDI protocol m32r-*-elf*
5217 * "set prompt-escape-char" command deleted.
5219 The command "set prompt-escape-char" has been deleted. This command,
5220 and its very obscure effet on GDB's prompt, was never documented,
5221 tested, nor mentioned in the NEWS file.
5223 * OBSOLETE configurations and files
5225 Configurations that have been declared obsolete in this release have
5226 been commented out. Unless there is activity to revive these
5227 configurations, the next release of GDB will have their sources
5228 permanently REMOVED.
5230 Sun 3, running SunOS 3 m68*-*-sunos3*
5231 Sun 3, running SunOS 4 m68*-*-sunos4*
5232 Sun 2, running SunOS 3 m68000-*-sunos3*
5233 Sun 2, running SunOS 4 m68000-*-sunos4*
5234 Motorola 680x0 running LynxOS m68*-*-lynxos*
5235 AT&T 3b1/Unix pc m68*-att-*
5236 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5237 decstation mips-dec-* mips-little-*
5238 riscos mips-*-riscos* mips-*-sysv*
5239 sonymips mips-sony-*
5240 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5242 * REMOVED configurations and files
5244 SGI Irix-4.x mips-sgi-irix4 or iris4
5245 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5246 Z8000 simulator z8k-zilog-none or z8ksim
5247 Matsushita MN10200 w/simulator mn10200-*-*
5248 H8/500 simulator h8500-hitachi-hms or h8500hms
5249 HP/PA running BSD hppa*-*-bsd*
5250 HP/PA running OSF/1 hppa*-*-osf*
5251 HP/PA Pro target hppa*-*-pro*
5252 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5253 386BSD i[3456]86-*-bsd*
5254 Sequent family i[3456]86-sequent-sysv4*
5255 i[3456]86-sequent-sysv*
5256 i[3456]86-sequent-bsd*
5257 SPARC running LynxOS sparc-*-lynxos*
5258 SPARC running SunOS 4 sparc-*-sunos4*
5259 Tsqware Sparclet sparclet-*-*
5260 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5262 *** Changes in GDB 6.0:
5266 Support for debugging the Objective-C programming language has been
5267 integrated into GDB.
5269 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5271 DWARF 2's Call Frame Information makes available compiler generated
5272 information that more exactly describes the program's run-time stack.
5273 By using this information, GDB is able to provide more robust stack
5276 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5277 have been updated to use a new backtrace mechanism which includes
5278 DWARF 2 CFI support.
5282 GDB's remote protocol has been extended to include support for hosted
5283 file I/O (where the remote target uses GDB's file system). See GDB's
5284 remote protocol documentation for details.
5286 * All targets using the new architecture framework.
5288 All of GDB's targets have been updated to use the new internal
5289 architecture framework. The way is now open for future GDB releases
5290 to include cross-architecture native debugging support (i386 on amd64,
5293 * GNU/Linux's Thread Local Storage (TLS)
5295 GDB now includes support for for the GNU/Linux implementation of
5296 per-thread variables.
5298 * GNU/Linux's Native POSIX Thread Library (NPTL)
5300 GDB's thread code has been updated to work with either the new
5301 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5303 * Separate debug info.
5305 GDB, in conjunction with BINUTILS, now supports a mechanism for
5306 automatically loading debug information from a separate file. Instead
5307 of shipping full debug and non-debug versions of system libraries,
5308 system integrators can now instead ship just the stripped libraries
5309 and optional debug files.
5311 * DWARF 2 Location Expressions
5313 DWARF 2 Location Expressions allow the compiler to more completely
5314 describe the location of variables (even in optimized code) to the
5317 GDB now includes preliminary support for location expressions (support
5318 for DW_OP_piece is still missing).
5322 A number of long standing bugs that caused GDB to die while starting a
5323 Java application have been fixed. GDB's Java support is now
5324 considered "useable".
5326 * GNU/Linux support for fork, vfork, and exec.
5328 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5329 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5332 * GDB supports logging output to a file
5334 There are two new commands, "set logging" and "show logging", which can be
5335 used to capture GDB's output to a file.
5337 * The meaning of "detach" has changed for gdbserver
5339 The "detach" command will now resume the application, as documented. To
5340 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5343 * d10v, m68hc11 `regs' command deprecated
5345 The `info registers' command has been updated so that it displays the
5346 registers using a format identical to the old `regs' command.
5350 A new command, "maint set profile on/off", has been added. This command can
5351 be used to enable or disable profiling while running GDB, to profile a
5352 session or a set of commands. In addition there is a new configure switch,
5353 "--enable-profiling", which will cause GDB to be compiled with profiling
5354 data, for more informative profiling results.
5356 * Default MI syntax changed to "mi2".
5358 The default MI (machine interface) syntax, enabled by the command line
5359 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5360 "mi1", can be enabled by specifying the option "-i=mi1".
5362 Support for the original "mi0" syntax (included in GDB 5.0) has been
5365 Fix for gdb/192: removed extraneous space when displaying frame level.
5366 Fix for gdb/672: update changelist is now output in mi list format.
5367 Fix for gdb/702: a -var-assign that updates the value now shows up
5368 in a subsequent -var-update.
5370 * New native configurations.
5372 FreeBSD/amd64 x86_64-*-freebsd*
5374 * Multi-arched targets.
5376 HP/PA HPUX11 hppa*-*-hpux*
5377 Renesas M32R/D w/simulator m32r-*-elf*
5379 * OBSOLETE configurations and files
5381 Configurations that have been declared obsolete in this release have
5382 been commented out. Unless there is activity to revive these
5383 configurations, the next release of GDB will have their sources
5384 permanently REMOVED.
5386 Z8000 simulator z8k-zilog-none or z8ksim
5387 Matsushita MN10200 w/simulator mn10200-*-*
5388 H8/500 simulator h8500-hitachi-hms or h8500hms
5389 HP/PA running BSD hppa*-*-bsd*
5390 HP/PA running OSF/1 hppa*-*-osf*
5391 HP/PA Pro target hppa*-*-pro*
5392 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5393 Sequent family i[3456]86-sequent-sysv4*
5394 i[3456]86-sequent-sysv*
5395 i[3456]86-sequent-bsd*
5396 Tsqware Sparclet sparclet-*-*
5397 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5399 * REMOVED configurations and files
5402 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5403 IBM AIX PS/2 i[3456]86-*-aix
5404 i386 running Mach 3.0 i[3456]86-*-mach3*
5405 i386 running Mach i[3456]86-*-mach*
5406 i386 running OSF/1 i[3456]86-*osf1mk*
5407 HP/Apollo 68k Family m68*-apollo*-sysv*,
5409 m68*-hp-bsd*, m68*-hp-hpux*
5410 Argonaut Risc Chip (ARC) arc-*-*
5411 Mitsubishi D30V d30v-*-*
5412 Fujitsu FR30 fr30-*-elf*
5413 OS/9000 i[34]86-*-os9k
5414 I960 with MON960 i960-*-coff
5416 * MIPS $fp behavior changed
5418 The convenience variable $fp, for the MIPS, now consistently returns
5419 the address of the current frame's base. Previously, depending on the
5420 context, $fp could refer to either $sp or the current frame's base
5421 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5422 The GNU Source-Level Debugger''.
5424 *** Changes in GDB 5.3:
5426 * GNU/Linux shared library multi-threaded performance improved.
5428 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5429 `/proc', in preference to `ptrace' for memory reads. This may result
5430 in an improvement in the start-up time of multi-threaded, shared
5431 library applications when run under GDB. One GDB user writes: ``loads
5432 shared libs like mad''.
5434 * ``gdbserver'' now supports multi-threaded applications on some targets
5436 Support for debugging multi-threaded applications which use
5437 the GNU/Linux LinuxThreads package has been added for
5438 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5439 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5441 * GDB now supports C/C++ preprocessor macros.
5443 GDB now expands preprocessor macro invocations in C/C++ expressions,
5444 and provides various commands for showing macro definitions and how
5447 The new command `macro expand EXPRESSION' expands any macro
5448 invocations in expression, and shows the result.
5450 The new command `show macro MACRO-NAME' shows the definition of the
5451 macro named MACRO-NAME, and where it was defined.
5453 Most compilers don't include information about macros in the debugging
5454 information by default. In GCC 3.1, for example, you need to compile
5455 your program with the options `-gdwarf-2 -g3'. If the macro
5456 information is present in the executable, GDB will read it.
5458 * Multi-arched targets.
5460 DEC Alpha (partial) alpha*-*-*
5461 DEC VAX (partial) vax-*-*
5463 National Semiconductor NS32000 (partial) ns32k-*-*
5464 Motorola 68000 (partial) m68k-*-*
5465 Motorola MCORE mcore-*-*
5469 Fujitsu FRV architecture added by Red Hat frv*-*-*
5472 * New native configurations
5474 Alpha NetBSD alpha*-*-netbsd*
5475 SH NetBSD sh*-*-netbsdelf*
5476 MIPS NetBSD mips*-*-netbsd*
5477 UltraSPARC NetBSD sparc64-*-netbsd*
5479 * OBSOLETE configurations and files
5481 Configurations that have been declared obsolete in this release have
5482 been commented out. Unless there is activity to revive these
5483 configurations, the next release of GDB will have their sources
5484 permanently REMOVED.
5486 Mitsubishi D30V d30v-*-*
5487 OS/9000 i[34]86-*-os9k
5488 IBM AIX PS/2 i[3456]86-*-aix
5489 Fujitsu FR30 fr30-*-elf*
5490 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5491 Argonaut Risc Chip (ARC) arc-*-*
5492 i386 running Mach 3.0 i[3456]86-*-mach3*
5493 i386 running Mach i[3456]86-*-mach*
5494 i386 running OSF/1 i[3456]86-*osf1mk*
5495 HP/Apollo 68k Family m68*-apollo*-sysv*,
5497 m68*-hp-bsd*, m68*-hp-hpux*
5498 I960 with MON960 i960-*-coff
5500 * OBSOLETE languages
5502 CHILL, a Pascal like language used by telecommunications companies.
5504 * REMOVED configurations and files
5506 AMD 29k family via UDI a29k-amd-udi, udi29k
5507 A29K VxWorks a29k-*-vxworks
5508 AMD 29000 embedded, using EBMON a29k-none-none
5509 AMD 29000 embedded with COFF a29k-none-coff
5510 AMD 29000 embedded with a.out a29k-none-aout
5512 testsuite/gdb.hp/gdb.threads-hp/ directory
5514 * New command "set max-user-call-depth <nnn>"
5516 This command allows the user to limit the call depth of user-defined
5517 commands. The default is 1024.
5519 * Changes in FreeBSD/i386 native debugging.
5521 Support for the "generate-core-file" has been added.
5523 * New commands "dump", "append", and "restore".
5525 These commands allow data to be copied from target memory
5526 to a bfd-format or binary file (dump and append), and back
5527 from a file into memory (restore).
5529 * Improved "next/step" support on multi-processor Alpha Tru64.
5531 The previous single-step mechanism could cause unpredictable problems,
5532 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5533 of a software single-step mechanism prevents this.
5535 *** Changes in GDB 5.2.1:
5543 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5544 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5545 Fix, by Joel Brobecker imported from mainline.
5547 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5548 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5549 Fix, by Fred Fish, imported from mainline.
5551 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5552 Surprisingly enough, it works now.
5553 By Michal Ludvig, imported from mainline.
5555 i386 hardware watchpoint support:
5556 avoid misses on second run for some targets.
5557 By Pierre Muller, imported from mainline.
5559 *** Changes in GDB 5.2:
5561 * New command "set trust-readonly-sections on[off]".
5563 This command is a hint that tells gdb that read-only sections
5564 really are read-only (ie. that their contents will not change).
5565 In this mode, gdb will go to the object file rather than the
5566 target to read memory from read-only sections (such as ".text").
5567 This can be a significant performance improvement on some
5568 (notably embedded) targets.
5570 * New command "generate-core-file" (or "gcore").
5572 This new gdb command allows the user to drop a core file of the child
5573 process state at any time. So far it's been implemented only for
5574 GNU/Linux and Solaris, but should be relatively easily ported to other
5575 hosts. Argument is core file name (defaults to core.<pid>).
5577 * New command line option
5579 GDB now accepts --pid or -p followed by a process id.
5581 * Change in command line behavior -- corefiles vs. process ids.
5583 There is a subtle behavior in the way in which GDB handles
5584 command line arguments. The first non-flag argument is always
5585 a program to debug, but the second non-flag argument may either
5586 be a corefile or a process id. Previously, GDB would attempt to
5587 open the second argument as a corefile, and if that failed, would
5588 issue a superfluous error message and then attempt to attach it as
5589 a process. Now, if the second argument begins with a non-digit,
5590 it will be treated as a corefile. If it begins with a digit,
5591 GDB will attempt to attach it as a process, and if no such process
5592 is found, will then attempt to open it as a corefile.
5594 * Changes in ARM configurations.
5596 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5597 configuration is fully multi-arch.
5599 * New native configurations
5601 ARM NetBSD arm*-*-netbsd*
5602 x86 OpenBSD i[3456]86-*-openbsd*
5603 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5604 Sparc64 running FreeBSD sparc64-*-freebsd*
5608 Sanyo XStormy16 xstormy16-elf
5610 * OBSOLETE configurations and files
5612 Configurations that have been declared obsolete in this release have
5613 been commented out. Unless there is activity to revive these
5614 configurations, the next release of GDB will have their sources
5615 permanently REMOVED.
5617 AMD 29k family via UDI a29k-amd-udi, udi29k
5618 A29K VxWorks a29k-*-vxworks
5619 AMD 29000 embedded, using EBMON a29k-none-none
5620 AMD 29000 embedded with COFF a29k-none-coff
5621 AMD 29000 embedded with a.out a29k-none-aout
5623 testsuite/gdb.hp/gdb.threads-hp/ directory
5625 * REMOVED configurations and files
5627 TI TMS320C80 tic80-*-*
5629 PowerPC Solaris powerpcle-*-solaris*
5630 PowerPC Windows NT powerpcle-*-cygwin32
5631 PowerPC Netware powerpc-*-netware*
5632 Harris/CXUX m88k m88*-harris-cxux*
5633 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5634 ns32k-utek-sysv* ns32k-utek-*
5635 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5636 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5637 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5638 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5639 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5641 * Changes to command line processing
5643 The new `--args' feature can be used to specify command-line arguments
5644 for the inferior from gdb's command line.
5646 * Changes to key bindings
5648 There is a new `operate-and-get-next' function bound to `C-o'.
5650 *** Changes in GDB 5.1.1
5652 Fix compile problem on DJGPP.
5654 Fix a problem with floating-point registers on the i386 being
5657 Fix to stop GDB crashing on .debug_str debug info.
5659 Numerous documentation fixes.
5661 Numerous testsuite fixes.
5663 *** Changes in GDB 5.1:
5665 * New native configurations
5667 Alpha FreeBSD alpha*-*-freebsd*
5668 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5669 MIPS GNU/Linux mips*-*-linux*
5670 MIPS SGI Irix 6.x mips*-sgi-irix6*
5671 ia64 AIX ia64-*-aix*
5672 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5676 Motorola 68HC11 and 68HC12 m68hc11-elf
5678 UltraSparc running GNU/Linux sparc64-*-linux*
5680 * OBSOLETE configurations and files
5682 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5683 Harris/CXUX m88k m88*-harris-cxux*
5684 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5685 ns32k-utek-sysv* ns32k-utek-*
5686 TI TMS320C80 tic80-*-*
5688 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5689 PowerPC Solaris powerpcle-*-solaris*
5690 PowerPC Windows NT powerpcle-*-cygwin32
5691 PowerPC Netware powerpc-*-netware*
5692 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5693 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5694 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5695 Apple Macintosh (MPW) host N/A
5697 stuff.c (Program to stuff files into a specially prepared space in kdb)
5698 kdb-start.c (Main loop for the standalone kernel debugger)
5700 Configurations that have been declared obsolete in this release have
5701 been commented out. Unless there is activity to revive these
5702 configurations, the next release of GDB will have their sources
5703 permanently REMOVED.
5705 * REMOVED configurations and files
5707 Altos 3068 m68*-altos-*
5708 Convex c1-*-*, c2-*-*
5710 ARM RISCix arm-*-* (as host)
5714 * GDB has been converted to ISO C.
5716 GDB's source code has been converted to ISO C. In particular, the
5717 sources are fully protoized, and rely on standard headers being
5722 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5724 * The MI enabled by default.
5726 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5727 revised and enabled by default. Packages which use GDB as a debugging
5728 engine behind a UI or another front end are encouraged to switch to
5729 using the GDB/MI interface, instead of the old annotations interface
5730 which is now deprecated.
5732 * Support for debugging Pascal programs.
5734 GDB now includes support for debugging Pascal programs. The following
5735 main features are supported:
5737 - Pascal-specific data types such as sets;
5739 - automatic recognition of Pascal sources based on file-name
5742 - Pascal-style display of data types, variables, and functions;
5744 - a Pascal expression parser.
5746 However, some important features are not yet supported.
5748 - Pascal string operations are not supported at all;
5750 - there are some problems with boolean types;
5752 - Pascal type hexadecimal constants are not supported
5753 because they conflict with the internal variables format;
5755 - support for Pascal objects and classes is not full yet;
5757 - unlike Pascal, GDB is case-sensitive for symbol names.
5759 * Changes in completion.
5761 Commands such as `shell', `run' and `set args', which pass arguments
5762 to inferior programs, now complete on file names, similar to what
5763 users expect at the shell prompt.
5765 Commands which accept locations, such as `disassemble', `print',
5766 `breakpoint', `until', etc. now complete on filenames as well as
5767 program symbols. Thus, if you type "break foob TAB", and the source
5768 files linked into the programs include `foobar.c', that file name will
5769 be one of the candidates for completion. However, file names are not
5770 considered for completion after you typed a colon that delimits a file
5771 name from a name of a function in that file, as in "break foo.c:bar".
5773 `set demangle-style' completes on available demangling styles.
5775 * New platform-independent commands:
5777 It is now possible to define a post-hook for a command as well as a
5778 hook that runs before the command. For more details, see the
5779 documentation of `hookpost' in the GDB manual.
5781 * Changes in GNU/Linux native debugging.
5783 Support for debugging multi-threaded programs has been completely
5784 revised for all platforms except m68k and sparc. You can now debug as
5785 many threads as your system allows you to have.
5787 Attach/detach is supported for multi-threaded programs.
5789 Support for SSE registers was added for x86. This doesn't work for
5790 multi-threaded programs though.
5792 * Changes in MIPS configurations.
5794 Multi-arch support is enabled for all MIPS configurations.
5796 GDB can now be built as native debugger on SGI Irix 6.x systems for
5797 debugging n32 executables. (Debugging 64-bit executables is not yet
5800 * Unified support for hardware watchpoints in all x86 configurations.
5802 Most (if not all) native x86 configurations support hardware-assisted
5803 breakpoints and watchpoints in a unified manner. This support
5804 implements debug register sharing between watchpoints, which allows to
5805 put a virtually infinite number of watchpoints on the same address,
5806 and also supports watching regions up to 16 bytes with several debug
5809 The new maintenance command `maintenance show-debug-regs' toggles
5810 debugging print-outs in functions that insert, remove, and test
5811 watchpoints and hardware breakpoints.
5813 * Changes in the DJGPP native configuration.
5815 New command ``info dos sysinfo'' displays assorted information about
5816 the CPU, OS, memory, and DPMI server.
5818 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5819 display information about segment descriptors stored in GDT, LDT, and
5822 New commands ``info dos pde'' and ``info dos pte'' display entries
5823 from Page Directory and Page Tables (for now works with CWSDPMI only).
5824 New command ``info dos address-pte'' displays the Page Table entry for
5825 a given linear address.
5827 GDB can now pass command lines longer than 126 characters to the
5828 program being debugged (requires an update to the libdbg.a library
5829 which is part of the DJGPP development kit).
5831 DWARF2 debug info is now supported.
5833 It is now possible to `step' and `next' through calls to `longjmp'.
5835 * Changes in documentation.
5837 All GDB documentation was converted to GFDL, the GNU Free
5838 Documentation License.
5840 Tracepoints-related commands are now fully documented in the GDB
5843 TUI, the Text-mode User Interface, is now documented in the manual.
5845 Tracepoints-related commands are now fully documented in the GDB
5848 The "GDB Internals" manual now has an index. It also includes
5849 documentation of `ui_out' functions, GDB coding standards, x86
5850 hardware watchpoints, and memory region attributes.
5852 * GDB's version number moved to ``version.in''
5854 The Makefile variable VERSION has been replaced by the file
5855 ``version.in''. People creating GDB distributions should update the
5856 contents of this file.
5860 GUD support is now a standard part of the EMACS distribution.
5862 *** Changes in GDB 5.0:
5864 * Improved support for debugging FP programs on x86 targets
5866 Unified and much-improved support for debugging floating-point
5867 programs on all x86 targets. In particular, ``info float'' now
5868 displays the FP registers in the same format on all x86 targets, with
5869 greater level of detail.
5871 * Improvements and bugfixes in hardware-assisted watchpoints
5873 It is now possible to watch array elements, struct members, and
5874 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5875 on x86 targets no longer erroneously trigger when the address is
5878 * Improvements in the native DJGPP version of GDB
5880 The distribution now includes all the scripts and auxiliary files
5881 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5882 machines ``out of the box''.
5884 The DJGPP version can now debug programs that use signals. It is
5885 possible to catch signals that happened in the debuggee, deliver
5886 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5887 would kill the program being debugged.) Programs that hook hardware
5888 interrupts (keyboard, timer, etc.) can also be debugged.
5890 It is now possible to debug DJGPP programs that redirect their
5891 standard handles or switch them to raw (as opposed to cooked) mode, or
5892 even close them. The command ``run < foo > bar'' works as expected,
5893 and ``info terminal'' reports useful information about the debuggee's
5894 terminal, including raw/cooked mode, redirection, etc.
5896 The DJGPP version now uses termios functions for console I/O, which
5897 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5900 DOS-style file names with drive letters are now fully supported by
5903 It is now possible to debug DJGPP programs that switch their working
5904 directory. It is also possible to rerun the debuggee any number of
5905 times without restarting GDB; thus, you can use the same setup,
5906 breakpoints, etc. for many debugging sessions.
5908 * New native configurations
5910 ARM GNU/Linux arm*-*-linux*
5911 PowerPC GNU/Linux powerpc-*-linux*
5915 Motorola MCore mcore-*-*
5916 x86 VxWorks i[3456]86-*-vxworks*
5917 PowerPC VxWorks powerpc-*-vxworks*
5918 TI TMS320C80 tic80-*-*
5920 * OBSOLETE configurations
5922 Altos 3068 m68*-altos-*
5923 Convex c1-*-*, c2-*-*
5925 ARM RISCix arm-*-* (as host)
5928 Configurations that have been declared obsolete will be commented out,
5929 but the code will be left in place. If there is no activity to revive
5930 these configurations before the next release of GDB, the sources will
5931 be permanently REMOVED.
5933 * Gould support removed
5935 Support for the Gould PowerNode and NP1 has been removed.
5937 * New features for SVR4
5939 On SVR4 native platforms (such as Solaris), if you attach to a process
5940 without first loading a symbol file, GDB will now attempt to locate and
5941 load symbols from the running process's executable file.
5943 * Many C++ enhancements
5945 C++ support has been greatly improved. Overload resolution now works properly
5946 in almost all cases. RTTI support is on the way.
5948 * Remote targets can connect to a sub-program
5950 A popen(3) style serial-device has been added. This device starts a
5951 sub-process (such as a stand-alone simulator) and then communicates
5952 with that. The sub-program to run is specified using the syntax
5953 ``|<program> <args>'' vis:
5955 (gdb) set remotedebug 1
5956 (gdb) target extended-remote |mn10300-elf-sim program-args
5958 * MIPS 64 remote protocol
5960 A long standing bug in the mips64 remote protocol where by GDB
5961 expected certain 32 bit registers (ex SR) to be transfered as 32
5962 instead of 64 bits has been fixed.
5964 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5965 added to provide backward compatibility with older versions of GDB.
5967 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5969 The command ``set remotebinarydownload'' command has been replaced by
5970 ``set remote X-packet''. Other commands in ``set remote'' family
5971 include ``set remote P-packet''.
5973 * Breakpoint commands accept ranges.
5975 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5976 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5977 ``tracepoint passcount'' also accepts a range of tracepoints.
5979 * ``apropos'' command added.
5981 The ``apropos'' command searches through command names and
5982 documentation strings, printing out matches, making it much easier to
5983 try to find a command that does what you are looking for.
5987 A new machine oriented interface (MI) has been added to GDB. This
5988 interface is designed for debug environments running GDB as a separate
5989 process. This is part of the long term libGDB project. See the
5990 "GDB/MI" chapter of the GDB manual for further information. It can be
5991 enabled by configuring with:
5993 .../configure --enable-gdbmi
5995 *** Changes in GDB-4.18:
5997 * New native configurations
5999 HP-UX 10.20 hppa*-*-hpux10.20
6000 HP-UX 11.x hppa*-*-hpux11.0*
6001 M68K GNU/Linux m68*-*-linux*
6005 Fujitsu FR30 fr30-*-elf*
6006 Intel StrongARM strongarm-*-*
6007 Mitsubishi D30V d30v-*-*
6009 * OBSOLETE configurations
6011 Gould PowerNode, NP1 np1-*-*, pn-*-*
6013 Configurations that have been declared obsolete will be commented out,
6014 but the code will be left in place. If there is no activity to revive
6015 these configurations before the next release of GDB, the sources will
6016 be permanently REMOVED.
6020 As a compatibility experiment, GDB's source files buildsym.h and
6021 buildsym.c have been converted to pure standard C, no longer
6022 containing any K&R compatibility code. We believe that all systems in
6023 use today either come with a standard C compiler, or have a GCC port
6024 available. If this is not true, please report the affected
6025 configuration to bug-gdb@gnu.org immediately. See the README file for
6026 information about getting a standard C compiler if you don't have one
6031 GDB now uses readline 2.2.
6033 * set extension-language
6035 You can now control the mapping between filename extensions and source
6036 languages by using the `set extension-language' command. For instance,
6037 you can ask GDB to treat .c files as C++ by saying
6038 set extension-language .c c++
6039 The command `info extensions' lists all of the recognized extensions
6040 and their associated languages.
6042 * Setting processor type for PowerPC and RS/6000
6044 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6045 you can use the `set processor' command to specify what variant of the
6046 PowerPC family you are debugging. The command
6050 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6051 following PowerPC and RS6000 variants:
6053 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6054 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6056 403GC IBM PowerPC 403GC
6057 505 Motorola PowerPC 505
6058 860 Motorola PowerPC 860 or 850
6059 601 Motorola PowerPC 601
6060 602 Motorola PowerPC 602
6061 603 Motorola/IBM PowerPC 603 or 603e
6062 604 Motorola PowerPC 604 or 604e
6063 750 Motorola/IBM PowerPC 750 or 750
6065 At the moment, this command just tells GDB what to name the
6066 special-purpose processor registers. Since almost all the affected
6067 registers are inaccessible to user-level programs, this command is
6068 only useful for remote debugging in its present form.
6072 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6073 more extensive support for HP-UX. Added features include shared
6074 library support, kernel threads and hardware watchpoints for 11.00,
6075 support for HP's ANSI C and C++ compilers, and a compatibility mode
6076 for xdb and dbx commands.
6080 HP's donation includes the new concept of catchpoints, which is a
6081 generalization of the old catch command. On HP-UX, it is now possible
6082 to catch exec, fork, and vfork, as well as library loading.
6084 This means that the existing catch command has changed; its first
6085 argument now specifies the type of catch to be set up. See the
6086 output of "help catch" for a list of catchpoint types.
6088 * Debugging across forks
6090 On HP-UX, you can choose which process to debug when a fork() happens
6095 HP has donated a curses-based terminal user interface (TUI). To get
6096 it, build with --enable-tui. Although this can be enabled for any
6097 configuration, at present it only works for native HP debugging.
6099 * GDB remote protocol additions
6101 A new protocol packet 'X' that writes binary data is now available.
6102 Default behavior is to try 'X', then drop back to 'M' if the stub
6103 fails to respond. The settable variable `remotebinarydownload'
6104 allows explicit control over the use of 'X'.
6106 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6107 full 64-bit address. The command
6109 set remoteaddresssize 32
6111 can be used to revert to the old behaviour. For existing remote stubs
6112 the change should not be noticed, as the additional address information
6115 In order to assist in debugging stubs, you may use the maintenance
6116 command `packet' to send any text string to the stub. For instance,
6118 maint packet heythere
6120 sends the packet "$heythere#<checksum>". Note that it is very easy to
6121 disrupt a debugging session by sending the wrong packet at the wrong
6124 The compare-sections command allows you to compare section data on the
6125 target to what is in the executable file without uploading or
6126 downloading, by comparing CRC checksums.
6128 * Tracing can collect general expressions
6130 You may now collect general expressions at tracepoints. This requires
6131 further additions to the target-side stub; see tracepoint.c and
6132 doc/agentexpr.texi for further details.
6134 * mask-address variable for Mips
6136 For Mips targets, you may control the zeroing of the upper 32 bits of
6137 a 64-bit address by entering `set mask-address on'. This is mainly
6138 of interest to users of embedded R4xxx and R5xxx processors.
6140 * Higher serial baud rates
6142 GDB's serial code now allows you to specify baud rates 57600, 115200,
6143 230400, and 460800 baud. (Note that your host system may not be able
6144 to achieve all of these rates.)
6148 The i960 configuration now includes an initial implementation of a
6149 builtin simulator, contributed by Jim Wilson.
6152 *** Changes in GDB-4.17:
6154 * New native configurations
6156 Alpha GNU/Linux alpha*-*-linux*
6157 Unixware 2.x i[3456]86-unixware2*
6158 Irix 6.x mips*-sgi-irix6*
6159 PowerPC GNU/Linux powerpc-*-linux*
6160 PowerPC Solaris powerpcle-*-solaris*
6161 Sparc GNU/Linux sparc-*-linux*
6162 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6166 Argonaut Risc Chip (ARC) arc-*-*
6167 Hitachi H8/300S h8300*-*-*
6168 Matsushita MN10200 w/simulator mn10200-*-*
6169 Matsushita MN10300 w/simulator mn10300-*-*
6170 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6171 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6172 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6173 Mitsubishi D10V w/simulator d10v-*-*
6174 Mitsubishi M32R/D w/simulator m32r-*-elf*
6175 Tsqware Sparclet sparclet-*-*
6176 NEC V850 w/simulator v850-*-*
6178 * New debugging protocols
6180 ARM with RDI protocol arm*-*-*
6181 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6182 DDB and LSI variants of PMON protocol mips*-*-*
6183 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6184 PowerPC with SDS protocol powerpc{,le}-*-eabi
6185 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6189 All configurations can now understand and use the DWARF 2 debugging
6190 format. The choice is automatic, if the symbol file contains DWARF 2
6195 GDB now includes basic Java language support. This support is
6196 only useful with Java compilers that produce native machine code.
6198 * solib-absolute-prefix and solib-search-path
6200 For SunOS and SVR4 shared libraries, you may now set the prefix for
6201 loading absolute shared library symbol files, and the search path for
6202 locating non-absolute shared library symbol files.
6204 * Live range splitting
6206 GDB can now effectively debug code for which GCC has performed live
6207 range splitting as part of its optimization. See gdb/doc/LRS for
6208 more details on the expected format of the stabs information.
6212 GDB's support for the GNU Hurd, including thread debugging, has been
6213 updated to work with current versions of the Hurd.
6217 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6218 instruction set. ARM GDB automatically detects when Thumb
6219 instructions are in use, and adjusts disassembly and backtracing
6224 GDB's MIPS target configurations now handle the MIP16 16-bit
6229 GDB now includes support for overlays; if an executable has been
6230 linked such that multiple sections are based at the same address, GDB
6231 will decide which section to use for symbolic info. You can choose to
6232 control the decision manually, using overlay commands, or implement
6233 additional target-side support and use "overlay load-target" to bring
6234 in the overlay mapping. Do "help overlay" for more detail.
6238 The command "info symbol <address>" displays information about
6239 the symbol at the specified address.
6243 The standard remote protocol now includes an extension that allows
6244 asynchronous collection and display of trace data. This requires
6245 extensive support in the target-side debugging stub. Tracing mode
6246 includes a new interaction mode in GDB and new commands: see the
6247 file tracepoint.c for more details.
6251 Configurations for embedded MIPS now include a simulator contributed
6252 by Cygnus Solutions. The simulator supports the instruction sets
6253 of most MIPS variants.
6257 Sparc configurations may now include the ERC32 simulator contributed
6258 by the European Space Agency. The simulator is not built into
6259 Sparc targets by default; configure with --enable-sim to include it.
6263 For target configurations that may include multiple variants of a
6264 basic architecture (such as MIPS and SH), you may now set the
6265 architecture explicitly. "set arch" sets, "info arch" lists
6266 the possible architectures.
6268 *** Changes in GDB-4.16:
6270 * New native configurations
6272 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6273 M68K NetBSD m68k-*-netbsd*
6274 PowerPC AIX 4.x powerpc-*-aix*
6275 PowerPC MacOS powerpc-*-macos*
6276 PowerPC Windows NT powerpcle-*-cygwin32
6277 RS/6000 AIX 4.x rs6000-*-aix4*
6281 ARM with RDP protocol arm-*-*
6282 I960 with MON960 i960-*-coff
6283 MIPS VxWorks mips*-*-vxworks*
6284 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6285 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6287 Matra Sparclet sparclet-*-*
6291 The powerpc-eabi configuration now includes the PSIM simulator,
6292 contributed by Andrew Cagney, with assistance from Mike Meissner.
6293 PSIM is a very elaborate model of the PowerPC, including not only
6294 basic instruction set execution, but also details of execution unit
6295 performance and I/O hardware. See sim/ppc/README for more details.
6299 GDB now works with Solaris 2.5.
6301 * Windows 95/NT native
6303 GDB will now work as a native debugger on Windows 95 and Windows NT.
6304 To build it from source, you must use the "gnu-win32" environment,
6305 which uses a DLL to emulate enough of Unix to run the GNU tools.
6306 Further information, binaries, and sources are available at
6307 ftp.cygnus.com, under pub/gnu-win32.
6309 * dont-repeat command
6311 If a user-defined command includes the command `dont-repeat', then the
6312 command will not be repeated if the user just types return. This is
6313 useful if the command is time-consuming to run, so that accidental
6314 extra keystrokes don't run the same command many times.
6316 * Send break instead of ^C
6318 The standard remote protocol now includes an option to send a break
6319 rather than a ^C to the target in order to interrupt it. By default,
6320 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6322 * Remote protocol timeout
6324 The standard remote protocol includes a new variable `remotetimeout'
6325 that allows you to set the number of seconds before GDB gives up trying
6326 to read from the target. The default value is 2.
6328 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6330 By default GDB will automatically keep track of objects as they are
6331 loaded and unloaded by the dynamic linker. By using the command `set
6332 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6333 when shared library events occur, thus allowing you to set breakpoints
6334 in shared libraries which are explicitly loaded by the inferior.
6336 Note this feature does not work on hpux8. On hpux9 you must link
6337 /usr/lib/end.o into your program. This feature should work
6338 automatically on hpux10.
6340 * Irix 5.x hardware watchpoint support
6342 Irix 5 configurations now support the use of hardware watchpoints.
6344 * Mips protocol "SYN garbage limit"
6346 When debugging a Mips target using the `target mips' protocol, you
6347 may set the number of characters that GDB will ignore by setting
6348 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6349 every character. The default value is 1050.
6351 * Recording and replaying remote debug sessions
6353 If you set `remotelogfile' to the name of a file, gdb will write to it
6354 a recording of a remote debug session. This recording may then be
6355 replayed back to gdb using "gdbreplay". See gdbserver/README for
6356 details. This is useful when you have a problem with GDB while doing
6357 remote debugging; you can make a recording of the session and send it
6358 to someone else, who can then recreate the problem.
6360 * Speedups for remote debugging
6362 GDB includes speedups for downloading and stepping MIPS systems using
6363 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6364 and more efficient S-record downloading.
6366 * Memory use reductions and statistics collection
6368 GDB now uses less memory and reports statistics about memory usage.
6369 Try the `maint print statistics' command, for example.
6371 *** Changes in GDB-4.15:
6373 * Psymtabs for XCOFF
6375 The symbol reader for AIX GDB now uses partial symbol tables. This
6376 can greatly improve startup time, especially for large executables.
6378 * Remote targets use caching
6380 Remote targets now use a data cache to speed up communication with the
6381 remote side. The data cache could lead to incorrect results because
6382 it doesn't know about volatile variables, thus making it impossible to
6383 debug targets which use memory mapped I/O devices. `set remotecache
6384 off' turns the the data cache off.
6386 * Remote targets may have threads
6388 The standard remote protocol now includes support for multiple threads
6389 in the target system, using new protocol commands 'H' and 'T'. See
6390 gdb/remote.c for details.
6394 If GDB is configured with `--enable-netrom', then it will include
6395 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6396 acts as though it is a bank of ROM on the target board, but you can
6397 write into it over the network. GDB's support consists only of
6398 support for fast loading into the emulated ROM; to debug, you must use
6399 another protocol, such as standard remote protocol. The usual
6400 sequence is something like
6402 target nrom <netrom-hostname>
6404 target remote <netrom-hostname>:1235
6408 GDB now includes support for the Apple Macintosh, as a host only. It
6409 may be run as either an MPW tool or as a standalone application, and
6410 it can debug through the serial port. All the usual GDB commands are
6411 available, but to the target command, you must supply "serial" as the
6412 device type instead of "/dev/ttyXX". See mpw-README in the main
6413 directory for more information on how to build. The MPW configuration
6414 scripts */mpw-config.in support only a few targets, and only the
6415 mips-idt-ecoff target has been tested.
6419 GDB configuration now uses autoconf. This is not user-visible,
6420 but does simplify configuration and building.
6424 GDB now supports hpux10.
6426 *** Changes in GDB-4.14:
6428 * New native configurations
6430 x86 FreeBSD i[345]86-*-freebsd
6431 x86 NetBSD i[345]86-*-netbsd
6432 NS32k NetBSD ns32k-*-netbsd
6433 Sparc NetBSD sparc-*-netbsd
6437 A29K VxWorks a29k-*-vxworks
6438 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6439 CPU32 EST-300 emulator m68*-*-est*
6440 PowerPC ELF powerpc-*-elf
6443 * Alpha OSF/1 support for procfs
6445 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6446 possible to attach to running processes. As the mounting of the /proc
6447 filesystem is optional on the Alpha, GDB automatically determines
6448 the availability of /proc during startup. This can lead to problems
6449 if /proc is unmounted after GDB has been started.
6451 * Arguments to user-defined commands
6453 User commands may accept up to 10 arguments separated by whitespace.
6454 Arguments are accessed within the user command via $arg0..$arg9. A
6457 print $arg0 + $arg1 + $arg2
6459 To execute the command use:
6462 Defines the command "adder" which prints the sum of its three arguments.
6463 Note the arguments are text substitutions, so they may reference variables,
6464 use complex expressions, or even perform inferior function calls.
6466 * New `if' and `while' commands
6468 This makes it possible to write more sophisticated user-defined
6469 commands. Both commands take a single argument, which is the
6470 expression to evaluate, and must be followed by the commands to
6471 execute, one per line, if the expression is nonzero, the list being
6472 terminated by the word `end'. The `if' command list may include an
6473 `else' word, which causes the following commands to be executed only
6474 if the expression is zero.
6476 * Fortran source language mode
6478 GDB now includes partial support for Fortran 77. It will recognize
6479 Fortran programs and can evaluate a subset of Fortran expressions, but
6480 variables and functions may not be handled correctly. GDB will work
6481 with G77, but does not yet know much about symbols emitted by other
6484 * Better HPUX support
6486 Most debugging facilities now work on dynamic executables for HPPAs
6487 running hpux9 or later. You can attach to running dynamically linked
6488 processes, but by default the dynamic libraries will be read-only, so
6489 for instance you won't be able to put breakpoints in them. To change
6490 that behavior do the following before running the program:
6496 This will cause the libraries to be mapped private and read-write.
6497 To revert to the normal behavior, do this:
6503 You cannot set breakpoints or examine data in the library until after
6504 the library is loaded if the function/data symbols do not have
6507 GDB can now also read debug symbols produced by the HP C compiler on
6508 HPPAs (sorry, no C++, Fortran or 68k support).
6510 * Target byte order now dynamically selectable
6512 You can choose which byte order to use with a target system, via the
6513 commands "set endian big" and "set endian little", and you can see the
6514 current setting by using "show endian". You can also give the command
6515 "set endian auto", in which case GDB will use the byte order
6516 associated with the executable. Currently, only embedded MIPS
6517 configurations support dynamic selection of target byte order.
6519 * New DOS host serial code
6521 This version uses DPMI interrupts to handle buffered I/O, so you
6522 no longer need to run asynctsr when debugging boards connected to
6525 *** Changes in GDB-4.13:
6527 * New "complete" command
6529 This lists all the possible completions for the rest of the line, if it
6530 were to be given as a command itself. This is intended for use by emacs.
6532 * Trailing space optional in prompt
6534 "set prompt" no longer adds a space for you after the prompt you set. This
6535 allows you to set a prompt which ends in a space or one that does not.
6537 * Breakpoint hit counts
6539 "info break" now displays a count of the number of times the breakpoint
6540 has been hit. This is especially useful in conjunction with "ignore"; you
6541 can ignore a large number of breakpoint hits, look at the breakpoint info
6542 to see how many times the breakpoint was hit, then run again, ignoring one
6543 less than that number, and this will get you quickly to the last hit of
6546 * Ability to stop printing at NULL character
6548 "set print null-stop" will cause GDB to stop printing the characters of
6549 an array when the first NULL is encountered. This is useful when large
6550 arrays actually contain only short strings.
6552 * Shared library breakpoints
6554 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6555 breakpoints in shared libraries before the executable is run.
6557 * Hardware watchpoints
6559 There is a new hardware breakpoint for the watch command for sparclite
6560 targets. See gdb/sparclite/hw_breakpoint.note.
6562 Hardware watchpoints are also now supported under GNU/Linux.
6566 Annotations have been added. These are for use with graphical interfaces,
6567 and are still experimental. Currently only gdba.el uses these.
6569 * Improved Irix 5 support
6571 GDB now works properly with Irix 5.2.
6573 * Improved HPPA support
6575 GDB now works properly with the latest GCC and GAS.
6577 * New native configurations
6579 Sequent PTX4 i[34]86-sequent-ptx4
6580 HPPA running OSF/1 hppa*-*-osf*
6581 Atari TT running SVR4 m68*-*-sysv4*
6582 RS/6000 LynxOS rs6000-*-lynxos*
6586 OS/9000 i[34]86-*-os9k
6587 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6590 * Hitachi SH7000 and E7000-PC ICE support
6592 There is now support for communicating with the Hitachi E7000-PC ICE.
6593 This is available automatically when GDB is configured for the SH.
6597 As usual, a variety of small fixes and improvements, both generic
6598 and configuration-specific. See the ChangeLog for more detail.
6600 *** Changes in GDB-4.12:
6602 * Irix 5 is now supported
6606 GDB-4.12 on the HPPA has a number of changes which make it unable
6607 to debug the output from the currently released versions of GCC and
6608 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6609 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6610 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6613 *** Changes in GDB-4.11:
6615 * User visible changes:
6619 The "set remotedebug" option is now consistent between the mips remote
6620 target, remote targets using the gdb-specific protocol, UDI (AMD's
6621 debug protocol for the 29k) and the 88k bug monitor. It is now an
6622 integer specifying a debug level (normally 0 or 1, but 2 means more
6623 debugging info for the mips target).
6625 * DEC Alpha native support
6627 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6628 debug info, but GDB works fairly well with the DEC compiler and should
6629 work with a future GCC release. See the README file for a few
6630 Alpha-specific notes.
6632 * Preliminary thread implementation
6634 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6636 * LynxOS native and target support for 386
6638 This release has been hosted on LynxOS 2.2, and also can be configured
6639 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6642 * Improvements in C++ mangling/demangling.
6644 This release has much better g++ debugging, specifically in name
6645 mangling/demangling, virtual function calls, print virtual table,
6646 call methods, ...etc.
6648 *** Changes in GDB-4.10:
6650 * User visible changes:
6652 Remote debugging using the GDB-specific (`target remote') protocol now
6653 supports the `load' command. This is only useful if you have some
6654 other way of getting the stub to the target system, and you can put it
6655 somewhere in memory where it won't get clobbered by the download.
6657 Filename completion now works.
6659 When run under emacs mode, the "info line" command now causes the
6660 arrow to point to the line specified. Also, "info line" prints
6661 addresses in symbolic form (as well as hex).
6663 All vxworks based targets now support a user settable option, called
6664 vxworks-timeout. This option represents the number of seconds gdb
6665 should wait for responses to rpc's. You might want to use this if
6666 your vxworks target is, perhaps, a slow software simulator or happens
6667 to be on the far side of a thin network line.
6671 This release contains support for using a DEC alpha as a GDB host for
6672 cross debugging. Native alpha debugging is not supported yet.
6675 *** Changes in GDB-4.9:
6679 This is the first GDB release which is accompanied by a matching testsuite.
6680 The testsuite requires installation of dejagnu, which should be available
6681 via ftp from most sites that carry GNU software.
6685 'Cfront' style demangling has had its name changed to 'ARM' style, to
6686 emphasize that it was written from the specifications in the C++ Annotated
6687 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6688 disclaimers, it still generated too much confusion with users attempting to
6689 use gdb with AT&T cfront.
6693 GDB now uses a standard remote interface to a simulator library.
6694 So far, the library contains simulators for the Zilog Z8001/2, the
6695 Hitachi H8/300, H8/500 and Super-H.
6697 * New targets supported
6699 H8/300 simulator h8300-hitachi-hms or h8300hms
6700 H8/500 simulator h8500-hitachi-hms or h8500hms
6701 SH simulator sh-hitachi-hms or sh
6702 Z8000 simulator z8k-zilog-none or z8ksim
6703 IDT MIPS board over serial line mips-idt-ecoff
6705 Cross-debugging to GO32 targets is supported. It requires a custom
6706 version of the i386-stub.c module which is integrated with the
6707 GO32 memory extender.
6709 * New remote protocols
6711 MIPS remote debugging protocol.
6713 * New source languages supported
6715 This version includes preliminary support for Chill, a Pascal like language
6716 used by telecommunications companies. Chill support is also being integrated
6717 into the GNU compiler, but we don't know when it will be publically available.
6720 *** Changes in GDB-4.8:
6722 * HP Precision Architecture supported
6724 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6725 version of this support was available as a set of patches from the
6726 University of Utah. GDB does not support debugging of programs
6727 compiled with the HP compiler, because HP will not document their file
6728 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6729 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6731 Many problems in the preliminary version have been fixed.
6733 * Faster and better demangling
6735 We have improved template demangling and fixed numerous bugs in the GNU style
6736 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6737 character types (wchar_t) are now supported. Demangling of each symbol is now
6738 only done once, and is cached when the symbol table for a file is read in.
6739 This results in a small increase in memory usage for C programs, a moderate
6740 increase in memory usage for C++ programs, and a fantastic speedup in
6743 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6744 from the specifications in the Annotated Reference Manual, which AT&T's
6745 compiler does not actually implement.
6747 * G++ multiple inheritance compiler problem
6749 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6750 inheritance lattices was reworked to properly discover ambiguities. We
6751 recently found an example which causes this new algorithm to fail in a
6752 very subtle way, producing bad debug information for those classes.
6753 The file 'gcc.patch' (in this directory) can be applied to gcc to
6754 circumvent the problem. A future GCC release will contain a complete
6757 The previous G++ debug info problem (mentioned below for the gdb-4.7
6758 release) is fixed in gcc version 2.3.2.
6760 * Improved configure script
6762 The `configure' script will now attempt to guess your system type if
6763 you don't supply a host system type. The old scheme of supplying a
6764 host system triplet is preferable over using this. All the magic is
6765 done in the new `config.guess' script. Examine it for details.
6767 We have also brought our configure script much more in line with the FSF's
6768 version. It now supports the --with-xxx options. In particular,
6769 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6770 The resulting GDB will not be able to read arbitrary object file formats --
6771 only the format ``expected'' to be used on the configured target system.
6772 We hope to make this the default in a future release.
6774 * Documentation improvements
6776 There's new internal documentation on how to modify GDB, and how to
6777 produce clean changes to the code. We implore people to read it
6778 before submitting changes.
6780 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6781 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6782 `info' files are also provided. To build `info' files from scratch,
6783 you will need the latest `makeinfo' release, which will be available in
6784 a future texinfo-X.Y release.
6786 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6787 We're not sure exactly which versions have this problem, but it has
6788 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6789 or better. If that isn't possible, there is a patch in
6790 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6791 around this problem.
6795 GDB now supports array constants that can be used in expressions typed in by
6796 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6797 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6800 The new directory `gdb/sparclite' contains a program that demonstrates
6801 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6803 * New native hosts supported
6805 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6806 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6808 * New targets supported
6810 AMD 29k family via UDI a29k-amd-udi or udi29k
6812 * New file formats supported
6814 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6815 HPUX core files, and SCO 3.2v2 core files.
6819 Attaching to processes now works again; thanks for the many bug reports.
6821 We have also stomped on a bunch of core dumps caused by
6822 printf_filtered("%s") problems.
6824 We eliminated a copyright problem on the rpc and ptrace header files
6825 for VxWorks, which was discovered at the last minute during the 4.7
6826 release. You should now be able to build a VxWorks GDB.
6828 You can now interrupt gdb while an attached process is running. This
6829 will cause the attached process to stop, and give control back to GDB.
6831 We fixed problems caused by using too many file descriptors
6832 for reading symbols from object files and libraries. This was
6833 especially a problem for programs that used many (~100) shared
6836 The `step' command now only enters a subroutine if there is line number
6837 information for the subroutine. Otherwise it acts like the `next'
6838 command. Previously, `step' would enter subroutines if there was
6839 any debugging information about the routine. This avoids problems
6840 when using `cc -g1' on MIPS machines.
6842 * Internal improvements
6844 GDB's internal interfaces have been improved to make it easier to support
6845 debugging of multiple languages in the future.
6847 GDB now uses a common structure for symbol information internally.
6848 Minimal symbols (derived from linkage symbols in object files), partial
6849 symbols (from a quick scan of debug information), and full symbols
6850 contain a common subset of information, making it easier to write
6851 shared code that handles any of them.
6853 * New command line options
6855 We now accept --silent as an alias for --quiet.
6859 The memory-mapped-malloc library is now licensed under the GNU Library
6860 General Public License.
6862 *** Changes in GDB-4.7:
6864 * Host/native/target split
6866 GDB has had some major internal surgery to untangle the support for
6867 hosts and remote targets. Now, when you configure GDB for a remote
6868 target, it will no longer load in all of the support for debugging
6869 local programs on the host. When fully completed and tested, this will
6870 ensure that arbitrary host/target combinations are possible.
6872 The primary conceptual shift is to separate the non-portable code in
6873 GDB into three categories. Host specific code is required any time GDB
6874 is compiled on that host, regardless of the target. Target specific
6875 code relates to the peculiarities of the target, but can be compiled on
6876 any host. Native specific code is everything else: it can only be
6877 built when the host and target are the same system. Child process
6878 handling and core file support are two common `native' examples.
6880 GDB's use of /proc for controlling Unix child processes is now cleaner.
6881 It has been split out into a single module under the `target_ops' vector,
6882 plus two native-dependent functions for each system that uses /proc.
6884 * New hosts supported
6886 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6887 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6888 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6890 * New targets supported
6892 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6893 68030 and CPU32 m68030-*-*, m68332-*-*
6895 * New native hosts supported
6897 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6898 (386bsd is not well tested yet)
6899 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6901 * New file formats supported
6903 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6904 supports reading of `a.out.adobe' object files, which are an a.out
6905 format extended with minimal information about multiple sections.
6909 `show copying' is the same as the old `info copying'.
6910 `show warranty' is the same as `info warrantee'.
6911 These were renamed for consistency. The old commands continue to work.
6913 `info handle' is a new alias for `info signals'.
6915 You can now define pre-command hooks, which attach arbitrary command
6916 scripts to any command. The commands in the hook will be executed
6917 prior to the user's command. You can also create a hook which will be
6918 executed whenever the program stops. See gdb.texinfo.
6922 We now deal with Cfront style name mangling, and can even extract type
6923 info from mangled symbols. GDB can automatically figure out which
6924 symbol mangling style your C++ compiler uses.
6926 Calling of methods and virtual functions has been improved as well.
6930 The crash that occured when debugging Sun Ansi-C compiled binaries is
6931 fixed. This was due to mishandling of the extra N_SO stabs output
6934 We also finally got Ultrix 4.2 running in house, and fixed core file
6935 support, with help from a dozen people on the net.
6937 John M. Farrell discovered that the reason that single-stepping was so
6938 slow on all of the Mips based platforms (primarily SGI and DEC) was
6939 that we were trying to demangle and lookup a symbol used for internal
6940 purposes on every instruction that was being stepped through. Changing
6941 the name of that symbol so that it couldn't be mistaken for a C++
6942 mangled symbol sped things up a great deal.
6944 Rich Pixley sped up symbol lookups in general by getting much smarter
6945 about when C++ symbol mangling is necessary. This should make symbol
6946 completion (TAB on the command line) much faster. It's not as fast as
6947 we'd like, but it's significantly faster than gdb-4.6.
6951 A new user controllable variable 'call_scratch_address' can
6952 specify the location of a scratch area to be used when GDB
6953 calls a function in the target. This is necessary because the
6954 usual method of putting the scratch area on the stack does not work
6955 in systems that have separate instruction and data spaces.
6957 We integrated changes to support the 29k UDI (Universal Debugger
6958 Interface), but discovered at the last minute that we didn't have all
6959 of the appropriate copyright paperwork. We are working with AMD to
6960 resolve this, and hope to have it available soon.
6964 We have sped up the remote serial line protocol, especially for targets
6965 with lots of registers. It now supports a new `expedited status' ('T')
6966 message which can be used in place of the existing 'S' status message.
6967 This allows the remote stub to send only the registers that GDB
6968 needs to make a quick decision about single-stepping or conditional
6969 breakpoints, eliminating the need to fetch the entire register set for
6970 each instruction being stepped through.
6972 The GDB remote serial protocol now implements a write-through cache for
6973 registers, only re-reading the registers if the target has run.
6975 There is also a new remote serial stub for SPARC processors. You can
6976 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6977 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6978 processor with a serial port.
6982 Configure.in files have become much easier to read and modify. A new
6983 `table driven' format makes it more obvious what configurations are
6984 supported, and what files each one uses.
6988 There is a new opcodes library which will eventually contain all of the
6989 disassembly routines and opcode tables. At present, it only contains
6990 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6991 disassembler (binutils/objdump) to share these routines.
6993 The libiberty library is now copylefted under the GNU Library General
6994 Public License. This allows more liberal use, and was done so libg++
6995 can use it. This makes no difference to GDB, since the Library License
6996 grants all the rights from the General Public License.
7000 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7001 reference to the stabs symbol info used by the debugger. It is (as far
7002 as we know) the only published document on this fascinating topic. We
7003 encourage you to read it, compare it to the stabs information on your
7004 system, and send improvements on the document in general (to
7005 bug-gdb@prep.ai.mit.edu).
7007 And, of course, many bugs have been fixed.
7010 *** Changes in GDB-4.6:
7012 * Better support for C++ function names
7014 GDB now accepts as input the "demangled form" of C++ overloaded function
7015 names and member function names, and can do command completion on such names
7016 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7017 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7018 Make use of command completion, it is your friend.
7020 GDB also now accepts a variety of C++ mangled symbol formats. They are
7021 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7022 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7023 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7024 for the list of formats.
7026 * G++ symbol mangling problem
7028 Recent versions of gcc have a bug in how they emit debugging information for
7029 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7030 directory) can be applied to gcc to fix the problem. Alternatively, if you
7031 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7032 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7033 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7036 * New 'maintenance' command
7038 All of the commands related to hacking GDB internals have been moved out of
7039 the main command set, and now live behind the 'maintenance' command. This
7040 can also be abbreviated as 'mt'. The following changes were made:
7042 dump-me -> maintenance dump-me
7043 info all-breakpoints -> maintenance info breakpoints
7044 printmsyms -> maintenance print msyms
7045 printobjfiles -> maintenance print objfiles
7046 printpsyms -> maintenance print psymbols
7047 printsyms -> maintenance print symbols
7049 The following commands are new:
7051 maintenance demangle Call internal GDB demangler routine to
7052 demangle a C++ link name and prints the result.
7053 maintenance print type Print a type chain for a given symbol
7055 * Change to .gdbinit file processing
7057 We now read the $HOME/.gdbinit file before processing the argv arguments
7058 (e.g. reading symbol files or core files). This allows global parameters to
7059 be set, which will apply during the symbol reading. The ./.gdbinit is still
7060 read after argv processing.
7062 * New hosts supported
7064 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7066 GNU/Linux support i386-unknown-linux or linux
7068 We are also including code to support the HP/PA running BSD and HPUX. This
7069 is almost guaranteed not to work, as we didn't have time to test or build it
7070 for this release. We are including it so that the more adventurous (or
7071 masochistic) of you can play with it. We also had major problems with the
7072 fact that the compiler that we got from HP doesn't support the -g option.
7075 * New targets supported
7077 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7079 * More smarts about finding #include files
7081 GDB now remembers the compilation directory for all include files, and for
7082 all files from which C is generated (like yacc and lex sources). This
7083 greatly improves GDB's ability to find yacc/lex sources, and include files,
7084 especially if you are debugging your program from a directory different from
7085 the one that contains your sources.
7087 We also fixed a bug which caused difficulty with listing and setting
7088 breakpoints in include files which contain C code. (In the past, you had to
7089 try twice in order to list an include file that you hadn't looked at before.)
7091 * Interesting infernals change
7093 GDB now deals with arbitrary numbers of sections, where the symbols for each
7094 section must be relocated relative to that section's landing place in the
7095 target's address space. This work was needed to support ELF with embedded
7096 stabs used by Solaris-2.0.
7098 * Bug fixes (of course!)
7100 There have been loads of fixes for the following things:
7101 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7102 i960, stabs, DOS(GO32), procfs, etc...
7104 See the ChangeLog for details.
7106 *** Changes in GDB-4.5:
7108 * New machines supported (host and target)
7110 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7112 SGI Irix-4.x mips-sgi-irix4 or iris4
7114 * New malloc package
7116 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7117 Mmalloc is capable of handling mutiple heaps of memory. It is also
7118 capable of saving a heap to a file, and then mapping it back in later.
7119 This can be used to greatly speedup the startup of GDB by using a
7120 pre-parsed symbol table which lives in a mmalloc managed heap. For
7121 more details, please read mmalloc/mmalloc.texi.
7125 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7126 'help info proc' for details.
7128 * MIPS ecoff symbol table format
7130 The code that reads MIPS symbol table format is now supported on all hosts.
7131 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7134 * File name changes for MS-DOS
7136 Many files in the config directories have been renamed to make it easier to
7137 support GDB on MS-DOSe systems (which have very restrictive file name
7138 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7139 environment) is close to working but has some remaining problems. Note
7140 that debugging of DOS programs is not supported, due to limitations
7141 in the ``operating system'', but it can be used to host cross-debugging.
7143 * Cross byte order fixes
7145 Many fixes have been made to support cross debugging of Sparc and MIPS
7146 targets from hosts whose byte order differs.
7148 * New -mapped and -readnow options
7150 If memory-mapped files are available on your system through the 'mmap'
7151 system call, you can use the -mapped option on the `file' or
7152 `symbol-file' commands to cause GDB to write the symbols from your
7153 program into a reusable file. If the program you are debugging is
7154 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7155 Future GDB debugging sessions will notice the presence of this file,
7156 and will quickly map in symbol information from it, rather than reading
7157 the symbol table from the executable program. Using the '-mapped'
7158 option in a GDB `file' or `symbol-file' command has the same effect as
7159 starting GDB with the '-mapped' command-line option.
7161 You can cause GDB to read the entire symbol table immediately by using
7162 the '-readnow' option with any of the commands that load symbol table
7163 information (or on the GDB command line). This makes the command
7164 slower, but makes future operations faster.
7166 The -mapped and -readnow options are typically combined in order to
7167 build a `fred.syms' file that contains complete symbol information.
7168 A simple GDB invocation to do nothing but build a `.syms' file for future
7171 gdb -batch -nx -mapped -readnow programname
7173 The `.syms' file is specific to the host machine on which GDB is run.
7174 It holds an exact image of GDB's internal symbol table. It cannot be
7175 shared across multiple host platforms.
7177 * longjmp() handling
7179 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7180 siglongjmp() without losing control. This feature has not yet been ported to
7181 all systems. It currently works on many 386 platforms, all MIPS-based
7182 platforms (SGI, DECstation, etc), and Sun3/4.
7186 Preliminary work has been put in to support the new Solaris OS from Sun. At
7187 this time, it can control and debug processes, but it is not capable of
7192 As always, many many bug fixes. The major areas were with g++, and mipsread.
7193 People using the MIPS-based platforms should experience fewer mysterious
7194 crashes and trashed symbol tables.
7196 *** Changes in GDB-4.4:
7198 * New machines supported (host and target)
7200 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7202 BSD Reno on Vax vax-dec-bsd
7203 Ultrix on Vax vax-dec-ultrix
7205 * New machines supported (target)
7207 AMD 29000 embedded, using EBMON a29k-none-none
7211 GDB continues to improve its handling of C++. `References' work better.
7212 The demangler has also been improved, and now deals with symbols mangled as
7213 per the Annotated C++ Reference Guide.
7215 GDB also now handles `stabs' symbol information embedded in MIPS
7216 `ecoff' symbol tables. Since the ecoff format was not easily
7217 extensible to handle new languages such as C++, this appeared to be a
7218 good way to put C++ debugging info into MIPS binaries. This option
7219 will be supported in the GNU C compiler, version 2, when it is
7222 * New features for SVR4
7224 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7225 shared libraries. Debugging dynamically linked programs should present
7226 only minor differences from debugging statically linked programs.
7228 The `info proc' command will print out information about any process
7229 on an SVR4 system (including the one you are debugging). At the moment,
7230 it prints the address mappings of the process.
7232 If you bring up GDB on another SVR4 system, please send mail to
7233 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7235 * Better dynamic linking support in SunOS
7237 Reading symbols from shared libraries which contain debugging symbols
7238 now works properly. However, there remain issues such as automatic
7239 skipping of `transfer vector' code during function calls, which
7240 make it harder to debug code in a shared library, than to debug the
7241 same code linked statically.
7245 GDB is now using the latest `getopt' routines from the FSF. This
7246 version accepts the -- prefix for options with long names. GDB will
7247 continue to accept the old forms (-option and +option) as well.
7248 Various single letter abbreviations for options have been explicity
7249 added to the option table so that they won't get overshadowed in the
7250 future by other options that begin with the same letter.
7254 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7255 Many assorted bugs have been handled. Many more remain to be handled.
7256 See the various ChangeLog files (primarily in gdb and bfd) for details.
7259 *** Changes in GDB-4.3:
7261 * New machines supported (host and target)
7263 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7264 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7265 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7267 * Almost SCO Unix support
7269 We had hoped to support:
7270 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7271 (except for core file support), but we discovered very late in the release
7272 that it has problems with process groups that render gdb unusable. Sorry
7273 about that. I encourage people to fix it and post the fixes.
7275 * Preliminary ELF and DWARF support
7277 GDB can read ELF object files on System V Release 4, and can handle
7278 debugging records for C, in DWARF format, in ELF files. This support
7279 is preliminary. If you bring up GDB on another SVR4 system, please
7280 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7285 GDB now uses the latest `readline' library. One user-visible change
7286 is that two tabs will list possible command completions, which previously
7287 required typing M-? (meta-question mark, or ESC ?).
7291 The `stepi' bug that many of you noticed has been squashed.
7292 Many bugs in C++ have been handled. Many more remain to be handled.
7293 See the various ChangeLog files (primarily in gdb and bfd) for details.
7295 * State of the MIPS world (in case you wondered):
7297 GDB can understand the symbol tables emitted by the compilers
7298 supplied by most vendors of MIPS-based machines, including DEC. These
7299 symbol tables are in a format that essentially nobody else uses.
7301 Some versions of gcc come with an assembler post-processor called
7302 mips-tfile. This program is required if you want to do source-level
7303 debugging of gcc-compiled programs. I believe FSF does not ship
7304 mips-tfile with gcc version 1, but it will eventually come with gcc
7307 Debugging of g++ output remains a problem. g++ version 1.xx does not
7308 really support it at all. (If you're lucky, you should be able to get
7309 line numbers and stack traces to work, but no parameters or local
7310 variables.) With some work it should be possible to improve the
7313 When gcc version 2 is released, you will have somewhat better luck.
7314 However, even then you will get confusing results for inheritance and
7317 We will eventually provide full debugging of g++ output on
7318 DECstations. This will probably involve some kind of stabs-in-ecoff
7319 encapulation, but the details have not been worked out yet.
7322 *** Changes in GDB-4.2:
7324 * Improved configuration
7326 Only one copy of `configure' exists now, and it is not self-modifying.
7327 Porting BFD is simpler.
7331 The `step' and `next' commands now only stop at the first instruction
7332 of a source line. This prevents the multiple stops that used to occur
7333 in switch statements, for-loops, etc. `Step' continues to stop if a
7334 function that has debugging information is called within the line.
7338 Lots of small bugs fixed. More remain.
7340 * New host supported (not target)
7342 Intel 386 PC clone running Mach i386-none-mach
7345 *** Changes in GDB-4.1:
7347 * Multiple source language support
7349 GDB now has internal scaffolding to handle several source languages.
7350 It determines the type of each source file from its filename extension,
7351 and will switch expression parsing and number formatting to match the
7352 language of the function in the currently selected stack frame.
7353 You can also specifically set the language to be used, with
7354 `set language c' or `set language modula-2'.
7358 GDB now has preliminary support for the GNU Modula-2 compiler,
7359 currently under development at the State University of New York at
7360 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7361 continue through the fall of 1991 and into 1992.
7363 Other Modula-2 compilers are currently not supported, and attempting to
7364 debug programs compiled with them will likely result in an error as the
7365 symbol table is read. Feel free to work on it, though!
7367 There are hooks in GDB for strict type checking and range checking,
7368 in the `Modula-2 philosophy', but they do not currently work.
7372 GDB can now write to executable and core files (e.g. patch
7373 a variable's value). You must turn this switch on, specify
7374 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7375 by assigning a new value to a variable. Modifications take
7378 * Automatic SunOS shared library reading
7380 When you run your program, GDB automatically determines where its
7381 shared libraries (if any) have been loaded, and reads their symbols.
7382 The `share' command is no longer needed. This also works when
7383 examining core files.
7387 You can specify the number of lines that the `list' command shows.
7390 * New machines supported (host and target)
7392 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7393 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7394 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7396 * New hosts supported (not targets)
7398 IBM RT/PC: romp-ibm-aix or rtpc
7400 * New targets supported (not hosts)
7402 AMD 29000 embedded with COFF a29k-none-coff
7403 AMD 29000 embedded with a.out a29k-none-aout
7404 Ultracomputer remote kernel debug a29k-nyu-kern
7406 * New remote interfaces
7412 *** Changes in GDB-4.0:
7416 Wide output is wrapped at good places to make the output more readable.
7418 Gdb now supports cross-debugging from a host machine of one type to a
7419 target machine of another type. Communication with the target system
7420 is over serial lines. The ``target'' command handles connecting to the
7421 remote system; the ``load'' command will download a program into the
7422 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7423 also supports debugging of realtime processes running under VxWorks,
7424 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7425 stub on the target system.
7427 New CPUs supported include the AMD 29000 and Intel 960.
7429 GDB now reads object files and symbol tables via a ``binary file''
7430 library, which allows a single copy of GDB to debug programs of multiple
7431 object file types such as a.out and coff.
7433 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7434 refcard.dvi and refcard.ps are available to format it).
7437 * Control-Variable user interface simplified
7439 All variables that control the operation of the debugger can be set
7440 by the ``set'' command, and displayed by the ``show'' command.
7442 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7443 ``Show prompt'' produces the response:
7444 Gdb's prompt is new-gdb=>.
7446 What follows are the NEW set commands. The command ``help set'' will
7447 print a complete list of old and new set commands. ``help set FOO''
7448 will give a longer description of the variable FOO. ``show'' will show
7449 all of the variable descriptions and their current settings.
7451 confirm on/off: Enables warning questions for operations that are
7452 hard to recover from, e.g. rerunning the program while
7453 it is already running. Default is ON.
7455 editing on/off: Enables EMACS style command line editing
7456 of input. Previous lines can be recalled with
7457 control-P, the current line can be edited with control-B,
7458 you can search for commands with control-R, etc.
7461 history filename NAME: NAME is where the gdb command history
7462 will be stored. The default is .gdb_history,
7463 or the value of the environment variable
7466 history size N: The size, in commands, of the command history. The
7467 default is 256, or the value of the environment variable
7470 history save on/off: If this value is set to ON, the history file will
7471 be saved after exiting gdb. If set to OFF, the
7472 file will not be saved. The default is OFF.
7474 history expansion on/off: If this value is set to ON, then csh-like
7475 history expansion will be performed on
7476 command line input. The default is OFF.
7478 radix N: Sets the default radix for input and output. It can be set
7479 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7480 in the current radix, so "set radix 10" is always a no-op.
7482 height N: This integer value is the number of lines on a page. Default
7483 is 24, the current `stty rows'' setting, or the ``li#''
7484 setting from the termcap entry matching the environment
7487 width N: This integer value is the number of characters on a line.
7488 Default is 80, the current `stty cols'' setting, or the ``co#''
7489 setting from the termcap entry matching the environment
7492 Note: ``set screensize'' is obsolete. Use ``set height'' and
7493 ``set width'' instead.
7495 print address on/off: Print memory addresses in various command displays,
7496 such as stack traces and structure values. Gdb looks
7497 more ``symbolic'' if you turn this off; it looks more
7498 ``machine level'' with it on. Default is ON.
7500 print array on/off: Prettyprint arrays. New convenient format! Default
7503 print demangle on/off: Print C++ symbols in "source" form if on,
7506 print asm-demangle on/off: Same, for assembler level printouts
7509 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7512 * Support for Epoch Environment.
7514 The epoch environment is a version of Emacs v18 with windowing. One
7515 new command, ``inspect'', is identical to ``print'', except that if you
7516 are running in the epoch environment, the value is printed in its own
7520 * Support for Shared Libraries
7522 GDB can now debug programs and core files that use SunOS shared libraries.
7523 Symbols from a shared library cannot be referenced
7524 before the shared library has been linked with the program (this
7525 happens after you type ``run'' and before the function main() is entered).
7526 At any time after this linking (including when examining core files
7527 from dynamically linked programs), gdb reads the symbols from each
7528 shared library when you type the ``sharedlibrary'' command.
7529 It can be abbreviated ``share''.
7531 sharedlibrary REGEXP: Load shared object library symbols for files
7532 matching a unix regular expression. No argument
7533 indicates to load symbols for all shared libraries.
7535 info sharedlibrary: Status of loaded shared libraries.
7540 A watchpoint stops execution of a program whenever the value of an
7541 expression changes. Checking for this slows down execution
7542 tremendously whenever you are in the scope of the expression, but is
7543 quite useful for catching tough ``bit-spreader'' or pointer misuse
7544 problems. Some machines such as the 386 have hardware for doing this
7545 more quickly, and future versions of gdb will use this hardware.
7547 watch EXP: Set a watchpoint (breakpoint) for an expression.
7549 info watchpoints: Information about your watchpoints.
7551 delete N: Deletes watchpoint number N (same as breakpoints).
7552 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7553 enable N: Re-enables watchpoint number N (same as breakpoints).
7556 * C++ multiple inheritance
7558 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7561 * C++ exception handling
7563 Gdb now supports limited C++ exception handling. Besides the existing
7564 ability to breakpoint on an exception handler, gdb can breakpoint on
7565 the raising of an exception (before the stack is peeled back to the
7568 catch FOO: If there is a FOO exception handler in the dynamic scope,
7569 set a breakpoint to catch exceptions which may be raised there.
7570 Multiple exceptions (``catch foo bar baz'') may be caught.
7572 info catch: Lists all exceptions which may be caught in the
7573 current stack frame.
7576 * Minor command changes
7578 The command ``call func (arg, arg, ...)'' now acts like the print
7579 command, except it does not print or save a value if the function's result
7580 is void. This is similar to dbx usage.
7582 The ``up'' and ``down'' commands now always print the frame they end up
7583 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7584 frames without printing.
7586 * New directory command
7588 'dir' now adds directories to the FRONT of the source search path.
7589 The path starts off empty. Source files that contain debug information
7590 about the directory in which they were compiled can be found even
7591 with an empty path; Sun CC and GCC include this information. If GDB can't
7592 find your source file in the current directory, type "dir .".
7594 * Configuring GDB for compilation
7596 For normal use, type ``./configure host''. See README or gdb.texinfo
7599 GDB now handles cross debugging. If you are remotely debugging between
7600 two different machines, type ``./configure host -target=targ''.
7601 Host is the machine where GDB will run; targ is the machine
7602 where the program that you are debugging will run.