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 * Building GDB now requires GNU readline >= 7.0.
304 GDB now bundles GNU readline 8.0, but if you choose to use
305 --with-system-readline, only readline >= 7.0 can be used.
307 *** Changes in GDB 8.3
309 * GDB and GDBserver now support access to additional registers on
310 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
313 * GDB now has experimental support for the compilation and injection of
314 C++ source code into the inferior. This beta release does not include
315 support for several language features, such as templates, constructors,
318 This feature requires GCC 7.1 or higher built with libcp1.so
321 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
322 can be passed using the '[ADDRESS]:PORT' notation, or the regular
323 'ADDRESS:PORT' method.
325 * DWARF index cache: GDB can now automatically save indices of DWARF
326 symbols on disk to speed up further loading of the same binaries.
328 * Ada task switching is now supported on aarch64-elf targets when
329 debugging a program using the Ravenscar Profile. For more information,
330 see the "Tasking Support when using the Ravenscar Profile" section
331 in the GDB user manual.
333 * GDB in batch mode now exits with status 1 if the last command to be
336 * The RISC-V target now supports target descriptions.
338 * System call catchpoints now support system call aliases on FreeBSD.
339 When the ABI of a system call changes in FreeBSD, this is
340 implemented by leaving a compatibility system call using the old ABI
341 at the existing number and allocating a new system call number for
342 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
343 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
344 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
345 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
346 so that a system call catchpoint for the 'kevent' system call will
347 catch invocations of both the 'kevent' and 'freebsd11_kevent'
348 binaries. This ensures that 'kevent' system calls are caught for
349 binaries using either the old or new ABIs.
351 * Terminal styling is now available for the CLI and the TUI. GNU
352 Source Highlight can additionally be used to provide styling of
353 source code snippets. See the "set style" commands, below, for more
356 * Removed support for old demangling styles arm, edg, gnu, hp and
361 set debug compile-cplus-types
362 show debug compile-cplus-types
363 Control the display of debug output about type conversion in the
364 C++ compile feature. Commands have no effect while compiliong
369 Control whether debug output about files/functions skipping is
372 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
373 Apply a command to some frames.
374 FLAG arguments allow to control what output to produce and how to handle
375 errors raised when applying COMMAND to a frame.
378 Apply a command to all threads (ignoring errors and empty output).
379 Shortcut for 'thread apply all -s COMMAND'.
382 Apply a command to all frames (ignoring errors and empty output).
383 Shortcut for 'frame apply all -s COMMAND'.
386 Apply a command to all frames of all threads (ignoring errors and empty
388 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
390 maint set dwarf unwinders (on|off)
391 maint show dwarf unwinders
392 Control whether DWARF unwinders can be used.
395 Display a list of open files for a process.
399 Changes to the "frame", "select-frame", and "info frame" CLI commands.
400 These commands all now take a frame specification which
401 is either a frame level, or one of the keywords 'level', 'address',
402 'function', or 'view' followed by a parameter. Selecting a frame by
403 address, or viewing a frame outside the current backtrace now
404 requires the use of a keyword. Selecting a frame by level is
405 unchanged. The MI comment "-stack-select-frame" is unchanged.
407 target remote FILENAME
408 target extended-remote FILENAME
409 If FILENAME is a Unix domain socket, GDB will attempt to connect
410 to this socket instead of opening FILENAME as a character device.
412 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
413 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
414 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
415 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
416 These commands can now print only the searched entities
417 matching the provided regexp(s), giving a condition
418 on the entity names or entity types. The flag -q disables
419 printing headers or informations messages.
425 These commands now determine the syntax for the shown entities
426 according to the language chosen by `set language'. In particular,
427 `set language auto' means to automatically choose the language of
430 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
431 The 'thread apply' command accepts new FLAG arguments.
432 FLAG arguments allow to control what output to produce and how to handle
433 errors raised when applying COMMAND to a thread.
435 set tui tab-width NCHARS
436 show tui tab-width NCHARS
437 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
439 set style enabled [on|off]
441 Enable or disable terminal styling. Styling is enabled by default
442 on most hosts, but disabled by default when in batch mode.
444 set style sources [on|off]
446 Enable or disable source code styling. Source code styling is
447 enabled by default, but only takes effect if styling in general is
448 enabled, and if GDB was linked with GNU Source Highlight.
450 set style filename foreground COLOR
451 set style filename background COLOR
452 set style filename intensity VALUE
453 Control the styling of file names.
455 set style function foreground COLOR
456 set style function background COLOR
457 set style function intensity VALUE
458 Control the styling of function names.
460 set style variable foreground COLOR
461 set style variable background COLOR
462 set style variable intensity VALUE
463 Control the styling of variable names.
465 set style address foreground COLOR
466 set style address background COLOR
467 set style address intensity VALUE
468 Control the styling of addresses.
472 ** The default version of the MI interpreter is now 3 (-i=mi3).
474 ** The '-data-disassemble' MI command now accepts an '-a' option to
475 disassemble the whole function surrounding the given program
476 counter value or function name. Support for this feature can be
477 verified by using the "-list-features" command, which should
478 contain "data-disassemble-a-option".
480 ** Command responses and notifications that include a frame now include
481 the frame's architecture in a new "arch" attribute.
483 ** The output of information about multi-location breakpoints (which is
484 syntactically incorrect in MI 2) has changed in MI 3. This affects
485 the following commands and events:
489 - =breakpoint-created
490 - =breakpoint-modified
492 The -fix-multi-location-breakpoint-output command can be used to enable
493 this behavior with previous MI versions.
495 * New native configurations
497 GNU/Linux/RISC-V riscv*-*-linux*
498 FreeBSD/riscv riscv*-*-freebsd*
502 GNU/Linux/RISC-V riscv*-*-linux*
504 CSKY GNU/LINUX csky*-*-linux
505 FreeBSD/riscv riscv*-*-freebsd*
507 GNU/Linux/OpenRISC or1k*-*-linux*
511 GDB no longer supports native debugging on versions of MS-Windows
516 ** GDB no longer supports Python versions less than 2.6.
518 ** The gdb.Inferior type has a new 'progspace' property, which is the program
519 space associated to that inferior.
521 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
522 of objfiles associated to that program space.
524 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
525 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
528 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
529 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
530 correct and did not work properly.
532 ** The gdb.Value type has a new constructor, which is used to construct a
533 gdb.Value from a Python buffer object and a gdb.Type.
539 Enable or disable the undefined behavior sanitizer. This is
540 disabled by default, but passing --enable-ubsan=yes or
541 --enable-ubsan=auto to configure will enable it. Enabling this can
542 cause a performance penalty. The undefined behavior sanitizer was
543 first introduced in GCC 4.9.
545 *** Changes in GDB 8.2
547 * The 'set disassembler-options' command now supports specifying options
550 * The 'symbol-file' command now accepts an '-o' option to add a relative
551 offset to all sections.
553 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
554 a relative offset to all sections, but it allows to override the load
555 address of individual sections using '-s'.
557 * The 'add-symbol-file' command no longer requires the second argument
558 (address of the text section).
560 * The endianness used with the 'set endian auto' mode in the absence of
561 an executable selected for debugging is now the last endianness chosen
562 either by one of the 'set endian big' and 'set endian little' commands
563 or by inferring from the last executable used, rather than the startup
566 * The pager now allows a "c" response, meaning to disable the pager
567 for the rest of the current command.
569 * The commands 'info variables/functions/types' now show the source line
570 numbers of symbol definitions when available.
572 * 'info proc' now works on running processes on FreeBSD systems and core
573 files created on FreeBSD systems.
575 * C expressions can now use _Alignof, and C++ expressions can now use
578 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
579 the vector length while the process is running.
585 Control display of debugging info regarding the FreeBSD native target.
587 set|show varsize-limit
588 This new setting allows the user to control the maximum size of Ada
589 objects being printed when those objects have a variable type,
590 instead of that maximum size being hardcoded to 65536 bytes.
592 set|show record btrace cpu
593 Controls the processor to be used for enabling errata workarounds for
596 maint check libthread-db
597 Run integrity checks on the current inferior's thread debugging
600 maint set check-libthread-db (on|off)
601 maint show check-libthread-db
602 Control whether to run integrity checks on inferior specific thread
603 debugging libraries as they are loaded. The default is not to
608 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
610 ** The commands attached to a breakpoint can be set by assigning to
611 the breakpoint's "commands" field.
613 ** gdb.execute can now execute multi-line gdb commands.
615 ** The new functions gdb.convenience_variable and
616 gdb.set_convenience_variable can be used to get and set the value
617 of convenience variables.
619 ** A gdb.Parameter will no longer print the "set" help text on an
620 ordinary "set"; instead by default a "set" will be silent unless
621 the get_set_string method returns a non-empty string.
625 RiscV ELF riscv*-*-elf
627 * Removed targets and native configurations
629 m88k running OpenBSD m88*-*-openbsd*
630 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
631 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
632 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
634 * Aarch64/Linux hardware watchpoints improvements
636 Hardware watchpoints on unaligned addresses are now properly
637 supported when running Linux kernel 4.10 or higher: read and access
638 watchpoints are no longer spuriously missed, and all watchpoints
639 lengths between 1 and 8 bytes are supported. On older kernels,
640 watchpoints set on unaligned addresses are no longer missed, with
641 the tradeoff that there is a possibility of false hits being
646 --enable-codesign=CERT
647 This can be used to invoke "codesign -s CERT" after building gdb.
648 This option is useful on macOS, where code signing is required for
649 gdb to work properly.
651 --disable-gdbcli has been removed
652 This is now silently accepted, but does nothing.
654 *** Changes in GDB 8.1
656 * GDB now supports dynamically creating arbitrary register groups specified
657 in XML target descriptions. This allows for finer grain grouping of
658 registers on systems with a large amount of registers.
660 * The 'ptype' command now accepts a '/o' flag, which prints the
661 offsets and sizes of fields in a struct, like the pahole(1) tool.
663 * New "--readnever" command line option instructs GDB to not read each
664 symbol file's symbolic debug information. This makes startup faster
665 but at the expense of not being able to perform symbolic debugging.
666 This option is intended for use cases where symbolic debugging will
667 not be used, e.g., when you only need to dump the debuggee's core.
669 * GDB now uses the GNU MPFR library, if available, to emulate target
670 floating-point arithmetic during expression evaluation when the target
671 uses different floating-point formats than the host. At least version
672 3.1 of GNU MPFR is required.
674 * GDB now supports access to the guarded-storage-control registers and the
675 software-based guarded-storage broadcast control registers on IBM z14.
677 * On Unix systems, GDB now supports transmitting environment variables
678 that are to be set or unset to GDBserver. These variables will
679 affect the environment to be passed to the remote inferior.
681 To inform GDB of environment variables that are to be transmitted to
682 GDBserver, use the "set environment" command. Only user set
683 environment variables are sent to GDBserver.
685 To inform GDB of environment variables that are to be unset before
686 the remote inferior is started by the GDBserver, use the "unset
687 environment" command.
689 * Completion improvements
691 ** GDB can now complete function parameters in linespecs and
692 explicit locations without quoting. When setting breakpoints,
693 quoting around functions names to help with TAB-completion is
694 generally no longer necessary. For example, this now completes
697 (gdb) b function(in[TAB]
698 (gdb) b function(int)
700 Related, GDB is no longer confused with completing functions in
701 C++ anonymous namespaces:
704 (gdb) b (anonymous namespace)::[TAB][TAB]
705 (anonymous namespace)::a_function()
706 (anonymous namespace)::b_function()
708 ** GDB now has much improved linespec and explicit locations TAB
709 completion support, that better understands what you're
710 completing and offers better suggestions. For example, GDB no
711 longer offers data symbols as possible completions when you're
712 setting a breakpoint.
714 ** GDB now TAB-completes label symbol names.
716 ** The "complete" command now mimics TAB completion accurately.
718 * New command line options (gcore)
721 Dump all memory mappings.
723 * Breakpoints on C++ functions are now set on all scopes by default
725 By default, breakpoints on functions/methods are now interpreted as
726 specifying all functions with the given name ignoring missing
727 leading scopes (namespaces and classes).
729 For example, assuming a C++ program with symbols named:
734 both commands "break func()" and "break B::func()" set a breakpoint
737 You can use the new flag "-qualified" to override this. This makes
738 GDB interpret the specified function name as a complete
739 fully-qualified name instead. For example, using the same C++
740 program, the "break -q B::func" command sets a breakpoint on
741 "B::func", only. A parameter has been added to the Python
742 gdb.Breakpoint constructor to achieve the same result when creating
743 a breakpoint from Python.
745 * Breakpoints on functions marked with C++ ABI tags
747 GDB can now set breakpoints on functions marked with C++ ABI tags
748 (e.g., [abi:cxx11]). See here for a description of ABI tags:
749 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
751 Functions with a C++11 abi tag are demangled/displayed like this:
753 function[abi:cxx11](int)
756 You can now set a breakpoint on such functions simply as if they had
759 (gdb) b function(int)
761 Or if you need to disambiguate between tags, like:
763 (gdb) b function[abi:other_tag](int)
765 Tab completion was adjusted accordingly as well.
769 ** New events gdb.new_inferior, gdb.inferior_deleted, and
770 gdb.new_thread are emitted. See the manual for further
771 description of these.
773 ** A new function, "gdb.rbreak" has been added to the Python API.
774 This function allows the setting of a large number of breakpoints
775 via a regex pattern in Python. See the manual for further details.
777 ** Python breakpoints can now accept explicit locations. See the
778 manual for a further description of this feature.
781 * New features in the GDB remote stub, GDBserver
783 ** GDBserver is now able to start inferior processes with a
784 specified initial working directory.
786 The user can set the desired working directory to be used from
787 GDB using the new "set cwd" command.
789 ** New "--selftest" command line option runs some GDBserver self
790 tests. These self tests are disabled in releases.
792 ** On Unix systems, GDBserver now does globbing expansion and variable
793 substitution in inferior command line arguments.
795 This is done by starting inferiors using a shell, like GDB does.
796 See "set startup-with-shell" in the user manual for how to disable
797 this from GDB when using "target extended-remote". When using
798 "target remote", you can disable the startup with shell by using the
799 new "--no-startup-with-shell" GDBserver command line option.
801 ** On Unix systems, GDBserver now supports receiving environment
802 variables that are to be set or unset from GDB. These variables
803 will affect the environment to be passed to the inferior.
805 * When catching an Ada exception raised with a message, GDB now prints
806 the message in the catchpoint hit notification. In GDB/MI mode, that
807 information is provided as an extra field named "exception-message"
808 in the *stopped notification.
810 * Trait objects can now be inspected When debugging Rust code. This
811 requires compiler support which will appear in Rust 1.24.
815 QEnvironmentHexEncoded
816 Inform GDBserver of an environment variable that is to be passed to
817 the inferior when starting it.
820 Inform GDBserver of an environment variable that is to be unset
821 before starting the remote inferior.
824 Inform GDBserver that the environment should be reset (i.e.,
825 user-set environment variables should be unset).
828 Indicates whether the inferior must be started with a shell or not.
831 Tell GDBserver that the inferior to be started should use a specific
834 * The "maintenance print c-tdesc" command now takes an optional
835 argument which is the file name of XML target description.
837 * The "maintenance selftest" command now takes an optional argument to
838 filter the tests to be run.
840 * The "enable", and "disable" commands now accept a range of
841 breakpoint locations, e.g. "enable 1.3-5".
846 Set and show the current working directory for the inferior.
849 Set and show compilation command used for compiling and injecting code
850 with the 'compile' commands.
852 set debug separate-debug-file
853 show debug separate-debug-file
854 Control the display of debug output about separate debug file search.
856 set dump-excluded-mappings
857 show dump-excluded-mappings
858 Control whether mappings marked with the VM_DONTDUMP flag should be
859 dumped when generating a core file.
862 List the registered selftests.
865 Start the debugged program stopping at the first instruction.
868 Control display of debugging messages related to OpenRISC targets.
870 set|show print type nested-type-limit
871 Set and show the limit of nesting level for nested types that the
872 type printer will show.
874 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
877 * Safer/improved support for debugging with no debug info
879 GDB no longer assumes functions with no debug information return
882 This means that GDB now refuses to call such functions unless you
883 tell it the function's type, by either casting the call to the
884 declared return type, or by casting the function to a function
885 pointer of the right type, and calling that:
887 (gdb) p getenv ("PATH")
888 'getenv' has unknown return type; cast the call to its declared return type
889 (gdb) p (char *) getenv ("PATH")
890 $1 = 0x7fffffffe "/usr/local/bin:/"...
891 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
892 $2 = 0x7fffffffe "/usr/local/bin:/"...
894 Similarly, GDB no longer assumes that global variables with no debug
895 info have type 'int', and refuses to print the variable's value
896 unless you tell it the variable's type:
899 'var' has unknown type; cast it to its declared type
903 * New native configurations
905 FreeBSD/aarch64 aarch64*-*-freebsd*
906 FreeBSD/arm arm*-*-freebsd*
910 FreeBSD/aarch64 aarch64*-*-freebsd*
911 FreeBSD/arm arm*-*-freebsd*
912 OpenRISC ELF or1k*-*-elf
914 * Removed targets and native configurations
916 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
918 *** Changes in GDB 8.0
920 * GDB now supports access to the PKU register on GNU/Linux. The register is
921 added by the Memory Protection Keys for Userspace feature which will be
922 available in future Intel CPUs.
924 * GDB now supports C++11 rvalue references.
928 ** New functions to start, stop and access a running btrace recording.
929 ** Rvalue references are now supported in gdb.Type.
931 * GDB now supports recording and replaying rdrand and rdseed Intel 64
934 * Building GDB and GDBserver now requires a C++11 compiler.
936 For example, GCC 4.8 or later.
938 It is no longer possible to build GDB or GDBserver with a C
939 compiler. The --disable-build-with-cxx configure option has been
942 * Building GDB and GDBserver now requires GNU make >= 3.81.
944 It is no longer supported to build GDB or GDBserver with another
945 implementation of the make program or an earlier version of GNU make.
947 * Native debugging on MS-Windows supports command-line redirection
949 Command-line arguments used for starting programs on MS-Windows can
950 now include redirection symbols supported by native Windows shells,
951 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
952 as "run", "start", and "set args", as well as the corresponding MI
955 * Support for thread names on MS-Windows.
957 GDB now catches and handles the special exception that programs
958 running on MS-Windows use to assign names to threads in the
961 * Support for Java programs compiled with gcj has been removed.
963 * User commands now accept an unlimited number of arguments.
964 Previously, only up to 10 was accepted.
966 * The "eval" command now expands user-defined command arguments.
968 This makes it easier to process a variable number of arguments:
973 eval "print $arg%d", $i
978 * Target descriptions can now describe registers for sparc32 and sparc64.
980 * GDB now supports DWARF version 5 (debug information format).
981 Its .debug_names index is not yet supported.
983 * New native configurations
985 FreeBSD/mips mips*-*-freebsd
989 Synopsys ARC arc*-*-elf32
990 FreeBSD/mips mips*-*-freebsd
992 * Removed targets and native configurations
994 Alpha running FreeBSD alpha*-*-freebsd*
995 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1000 Erases all the flash memory regions reported by the target.
1002 maint print arc arc-instruction address
1003 Print internal disassembler information about instruction at a given address.
1007 set disassembler-options
1008 show disassembler-options
1009 Controls the passing of target specific information to the disassembler.
1010 If it is necessary to specify more than one disassembler option then
1011 multiple options can be placed together into a comma separated list.
1012 The default value is the empty string. Currently, the only supported
1013 targets are ARM, PowerPC and S/390.
1018 Erases all the flash memory regions reported by the target. This is
1019 equivalent to the CLI command flash-erase.
1021 -file-list-shared-libraries
1022 List the shared libraries in the program. This is
1023 equivalent to the CLI command "info shared".
1026 Catchpoints stopping the program when Ada exceptions are
1027 handled. This is equivalent to the CLI command "catch handlers".
1029 *** Changes in GDB 7.12
1031 * GDB and GDBserver now build with a C++ compiler by default.
1033 The --enable-build-with-cxx configure option is now enabled by
1034 default. One must now explicitly configure with
1035 --disable-build-with-cxx in order to build with a C compiler. This
1036 option will be removed in a future release.
1038 * GDBserver now supports recording btrace without maintaining an active
1041 * GDB now supports a negative repeat count in the 'x' command to examine
1042 memory backward from the given address. For example:
1045 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1046 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1047 (gdb) x/-5i 0x0000000000400580
1048 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1049 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1050 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1051 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1052 0x40057b <main(int, char**)+25>:
1053 callq 0x400536 <Func1(int, char const*)>
1055 * Fortran: Support structures with fields of dynamic types and
1056 arrays of dynamic types.
1058 * The symbol dumping maintenance commands have new syntax.
1059 maint print symbols [-pc address] [--] [filename]
1060 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1061 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1062 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1063 maint print msymbols [-objfile objfile] [--] [filename]
1065 * GDB now supports multibit bitfields and enums in target register
1068 * New Python-based convenience function $_as_string(val), which returns
1069 the textual representation of a value. This function is especially
1070 useful to obtain the text label of an enum value.
1072 * Intel MPX bound violation handling.
1074 Segmentation faults caused by a Intel MPX boundary violation
1075 now display the kind of violation (upper or lower), the memory
1076 address accessed and the memory bounds, along with the usual
1077 signal received and code location.
1081 Program received signal SIGSEGV, Segmentation fault
1082 Upper bound violation while accessing address 0x7fffffffc3b3
1083 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1084 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1086 * Rust language support.
1087 GDB now supports debugging programs written in the Rust programming
1088 language. See https://www.rust-lang.org/ for more information about
1091 * Support for running interpreters on specified input/output devices
1093 GDB now supports a new mechanism that allows frontends to provide
1094 fully featured GDB console views, as a better alternative to
1095 building such views on top of the "-interpreter-exec console"
1096 command. See the new "new-ui" command below. With that command,
1097 frontends can now start GDB in the traditional command-line mode
1098 running in an embedded terminal emulator widget, and create a
1099 separate MI interpreter running on a specified i/o device. In this
1100 way, GDB handles line editing, history, tab completion, etc. in the
1101 console all by itself, and the GUI uses the separate MI interpreter
1102 for its own control and synchronization, invisible to the command
1105 * The "catch syscall" command catches groups of related syscalls.
1107 The "catch syscall" command now supports catching a group of related
1108 syscalls using the 'group:' or 'g:' prefix.
1113 skip -gfile file-glob-pattern
1114 skip -function function
1115 skip -rfunction regular-expression
1116 A generalized form of the skip command, with new support for
1117 glob-style file names and regular expressions for function names.
1118 Additionally, a file spec and a function spec may now be combined.
1120 maint info line-table REGEXP
1121 Display the contents of GDB's internal line table data struture.
1124 Run any GDB unit tests that were compiled in.
1127 Start a new user interface instance running INTERP as interpreter,
1128 using the TTY file for input/output.
1132 ** gdb.Breakpoint objects have a new attribute "pending", which
1133 indicates whether the breakpoint is pending.
1134 ** Three new breakpoint-related events have been added:
1135 gdb.breakpoint_created, gdb.breakpoint_modified, and
1136 gdb.breakpoint_deleted.
1138 signal-event EVENTID
1139 Signal ("set") the given MS-Windows event object. This is used in
1140 conjunction with the Windows JIT debugging (AeDebug) support, where
1141 the OS suspends a crashing process until a debugger can attach to
1142 it. Resuming the crashing process, in order to debug it, is done by
1143 signalling an event.
1145 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1146 was added in GDBserver, including JIT compiling fast tracepoint's
1147 conditional expression bytecode into native code.
1149 * Support for various remote target protocols and ROM monitors has
1152 target m32rsdi Remote M32R debugging over SDI
1153 target mips MIPS remote debugging protocol
1154 target pmon PMON ROM monitor
1155 target ddb NEC's DDB variant of PMON for Vr4300
1156 target rockhopper NEC RockHopper variant of PMON
1157 target lsi LSI variant of PMO
1159 * Support for tracepoints and fast tracepoints on powerpc-linux,
1160 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1161 including JIT compiling fast tracepoint's conditional expression
1162 bytecode into native code.
1164 * MI async record =record-started now includes the method and format used for
1165 recording. For example:
1167 =record-started,thread-group="i1",method="btrace",format="bts"
1169 * MI async record =thread-selected now includes the frame field. For example:
1171 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1175 Andes NDS32 nds32*-*-elf
1177 *** Changes in GDB 7.11
1179 * GDB now supports debugging kernel-based threads on FreeBSD.
1181 * Per-inferior thread numbers
1183 Thread numbers are now per inferior instead of global. If you're
1184 debugging multiple inferiors, GDB displays thread IDs using a
1185 qualified INF_NUM.THR_NUM form. For example:
1189 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1190 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1191 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1192 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1194 As consequence, thread numbers as visible in the $_thread
1195 convenience variable and in Python's InferiorThread.num attribute
1196 are no longer unique between inferiors.
1198 GDB now maintains a second thread ID per thread, referred to as the
1199 global thread ID, which is the new equivalent of thread numbers in
1200 previous releases. See also $_gthread below.
1202 For backwards compatibility, MI's thread IDs always refer to global
1205 * Commands that accept thread IDs now accept the qualified
1206 INF_NUM.THR_NUM form as well. For example:
1209 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1212 * In commands that accept a list of thread IDs, you can now refer to
1213 all threads of an inferior using a star wildcard. GDB accepts
1214 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1215 refer to all threads of the current inferior. For example, "info
1218 * You can use "info threads -gid" to display the global thread ID of
1221 * The new convenience variable $_gthread holds the global number of
1224 * The new convenience variable $_inferior holds the number of the
1227 * GDB now displays the ID and name of the thread that hit a breakpoint
1228 or received a signal, if your program is multi-threaded. For
1231 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1232 Thread 1 "main" received signal SIGINT, Interrupt.
1234 * Record btrace now supports non-stop mode.
1236 * Support for tracepoints on aarch64-linux was added in GDBserver.
1238 * The 'record instruction-history' command now indicates speculative execution
1239 when using the Intel Processor Trace recording format.
1241 * GDB now allows users to specify explicit locations, bypassing
1242 the linespec parser. This feature is also available to GDB/MI
1245 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1246 GDB now is able to debug both AArch64 applications and ARM applications
1249 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1250 including JIT compiling fast tracepoint's conditional expression bytecode
1253 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1255 * "info threads", "info inferiors", "info display", "info checkpoints"
1256 and "maint info program-spaces" now list the corresponding items in
1257 ascending ID order, for consistency with all other "info" commands.
1259 * In Ada, the overloads selection menu has been enhanced to display the
1260 parameter types and the return types for the matching overloaded subprograms.
1264 maint set target-non-stop (on|off|auto)
1265 maint show target-non-stop
1266 Control whether GDB targets always operate in non-stop mode even if
1267 "set non-stop" is "off". The default is "auto", meaning non-stop
1268 mode is enabled if supported by the target.
1270 maint set bfd-sharing
1271 maint show bfd-sharing
1272 Control the reuse of bfd objects.
1275 show debug bfd-cache
1276 Control display of debugging info regarding bfd caching.
1280 Control display of debugging info regarding FreeBSD threads.
1282 set remote multiprocess-extensions-packet
1283 show remote multiprocess-extensions-packet
1284 Set/show the use of the remote protocol multiprocess extensions.
1286 set remote thread-events
1287 show remote thread-events
1288 Set/show the use of thread create/exit events.
1290 set ada print-signatures on|off
1291 show ada print-signatures"
1292 Control whether parameter types and return types are displayed in overloads
1293 selection menus. It is activaled (@code{on}) by default.
1297 Controls the maximum size of memory, in bytes, that GDB will
1298 allocate for value contents. Prevents incorrect programs from
1299 causing GDB to allocate overly large buffers. Default is 64k.
1301 * The "disassemble" command accepts a new modifier: /s.
1302 It prints mixed source+disassembly like /m with two differences:
1303 - disassembled instructions are now printed in program order, and
1304 - and source for all relevant files is now printed.
1305 The "/m" option is now considered deprecated: its "source-centric"
1306 output hasn't proved useful in practice.
1308 * The "record instruction-history" command accepts a new modifier: /s.
1309 It behaves exactly like /m and prints mixed source+disassembly.
1311 * The "set scheduler-locking" command supports a new mode "replay".
1312 It behaves like "off" in record mode and like "on" in replay mode.
1314 * Support for various ROM monitors has been removed:
1316 target dbug dBUG ROM monitor for Motorola ColdFire
1317 target picobug Motorola picobug monitor
1318 target dink32 DINK32 ROM monitor for PowerPC
1319 target m32r Renesas M32R/D ROM monitor
1320 target mon2000 mon2000 ROM monitor
1321 target ppcbug PPCBUG ROM monitor for PowerPC
1323 * Support for reading/writing memory and extracting values on architectures
1324 whose memory is addressable in units of any integral multiple of 8 bits.
1327 Allows to break when an Ada exception is handled.
1329 * New remote packets
1332 Indicates that an exec system call was executed.
1334 exec-events feature in qSupported
1335 The qSupported packet allows GDB to request support for exec
1336 events using the new 'gdbfeature' exec-event, and the qSupported
1337 response can contain the corresponding 'stubfeature'. Set and
1338 show commands can be used to display whether these features are enabled.
1341 Equivalent to interrupting with the ^C character, but works in
1344 thread created stop reason (T05 create:...)
1345 Indicates that the thread was just created and is stopped at entry.
1347 thread exit stop reply (w exitcode;tid)
1348 Indicates that the thread has terminated.
1351 Enables/disables thread create and exit event reporting. For
1352 example, this is used in non-stop mode when GDB stops a set of
1353 threads and synchronously waits for the their corresponding stop
1354 replies. Without exit events, if one of the threads exits, GDB
1355 would hang forever not knowing that it should no longer expect a
1356 stop for that same thread.
1359 Indicates that there are no resumed threads left in the target (all
1360 threads are stopped). The remote stub reports support for this stop
1361 reply to GDB's qSupported query.
1364 Enables/disables catching syscalls from the inferior process.
1365 The remote stub reports support for this packet to GDB's qSupported query.
1367 syscall_entry stop reason
1368 Indicates that a syscall was just called.
1370 syscall_return stop reason
1371 Indicates that a syscall just returned.
1373 * Extended-remote exec events
1375 ** GDB now has support for exec events on extended-remote Linux targets.
1376 For such targets with Linux kernels 2.5.46 and later, this enables
1377 follow-exec-mode and exec catchpoints.
1379 set remote exec-event-feature-packet
1380 show remote exec-event-feature-packet
1381 Set/show the use of the remote exec event feature.
1383 * Thread names in remote protocol
1385 The reply to qXfer:threads:read may now include a name attribute for each
1388 * Target remote mode fork and exec events
1390 ** GDB now has support for fork and exec events on target remote mode
1391 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1392 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1393 fork and exec catchpoints.
1395 * Remote syscall events
1397 ** GDB now has support for catch syscall on remote Linux targets,
1398 currently enabled on x86/x86_64 architectures.
1400 set remote catch-syscall-packet
1401 show remote catch-syscall-packet
1402 Set/show the use of the remote catch syscall feature.
1406 ** The -var-set-format command now accepts the zero-hexadecimal
1407 format. It outputs data in hexadecimal format with zero-padding on the
1412 ** gdb.InferiorThread objects have a new attribute "global_num",
1413 which refers to the thread's global thread ID. The existing
1414 "num" attribute now refers to the thread's per-inferior number.
1415 See "Per-inferior thread numbers" above.
1416 ** gdb.InferiorThread objects have a new attribute "inferior", which
1417 is the Inferior object the thread belongs to.
1419 *** Changes in GDB 7.10
1421 * Support for process record-replay and reverse debugging on aarch64*-linux*
1422 targets has been added. GDB now supports recording of A64 instruction set
1423 including advance SIMD instructions.
1425 * Support for Sun's version of the "stabs" debug file format has been removed.
1427 * GDB now honors the content of the file /proc/PID/coredump_filter
1428 (PID is the process ID) on GNU/Linux systems. This file can be used
1429 to specify the types of memory mappings that will be included in a
1430 corefile. For more information, please refer to the manual page of
1431 "core(5)". GDB also has a new command: "set use-coredump-filter
1432 on|off". It allows to set whether GDB will read the content of the
1433 /proc/PID/coredump_filter file when generating a corefile.
1435 * The "info os" command on GNU/Linux can now display information on
1437 "info os cpus" Listing of all cpus/cores on the system
1439 * GDB has two new commands: "set serial parity odd|even|none" and
1440 "show serial parity". These allows to set or show parity for the
1443 * The "info source" command now displays the producer string if it was
1444 present in the debug info. This typically includes the compiler version
1445 and may include things like its command line arguments.
1447 * The "info dll", an alias of the "info sharedlibrary" command,
1448 is now available on all platforms.
1450 * Directory names supplied to the "set sysroot" commands may be
1451 prefixed with "target:" to tell GDB to access shared libraries from
1452 the target system, be it local or remote. This replaces the prefix
1453 "remote:". The default sysroot has been changed from "" to
1454 "target:". "remote:" is automatically converted to "target:" for
1455 backward compatibility.
1457 * The system root specified by "set sysroot" will be prepended to the
1458 filename of the main executable (if reported to GDB as absolute by
1459 the operating system) when starting processes remotely, and when
1460 attaching to already-running local or remote processes.
1462 * GDB now supports automatic location and retrieval of executable
1463 files from remote targets. Remote debugging can now be initiated
1464 using only a "target remote" or "target extended-remote" command
1465 (no "set sysroot" or "file" commands are required). See "New remote
1468 * The "dump" command now supports verilog hex format.
1470 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1472 * On GNU/Linux, GDB and gdbserver are now able to access executable
1473 and shared library files without a "set sysroot" command when
1474 attaching to processes running in different mount namespaces from
1475 the debugger. This makes it possible to attach to processes in
1476 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1477 See "New remote packets" below.
1479 * The "tui reg" command now provides completion for all of the
1480 available register groups, including target specific groups.
1482 * The HISTSIZE environment variable is no longer read when determining
1483 the size of GDB's command history. GDB now instead reads the dedicated
1484 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1485 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1490 ** Memory ports can now be unbuffered.
1494 ** gdb.Objfile objects have a new attribute "username",
1495 which is the name of the objfile as specified by the user,
1496 without, for example, resolving symlinks.
1497 ** You can now write frame unwinders in Python.
1498 ** gdb.Type objects have a new method "optimized_out",
1499 returning optimized out gdb.Value instance of this type.
1500 ** gdb.Value objects have new methods "reference_value" and
1501 "const_value" which return a reference to the value and a
1502 "const" version of the value respectively.
1506 maint print symbol-cache
1507 Print the contents of the symbol cache.
1509 maint print symbol-cache-statistics
1510 Print statistics of symbol cache usage.
1512 maint flush-symbol-cache
1513 Flush the contents of the symbol cache.
1517 Start branch trace recording using Branch Trace Store (BTS) format.
1520 Evaluate expression by using the compiler and print result.
1524 Explicit commands for enabling and disabling tui mode.
1527 set mpx bound on i386 and amd64
1528 Support for bound table investigation on Intel MPX enabled applications.
1532 Start branch trace recording using Intel Processor Trace format.
1535 Print information about branch tracing internals.
1537 maint btrace packet-history
1538 Print the raw branch tracing data.
1540 maint btrace clear-packet-history
1541 Discard the stored raw branch tracing data.
1544 Discard all branch tracing data. It will be fetched and processed
1545 anew by the next "record" command.
1550 Renamed from "set debug dwarf2-die".
1551 show debug dwarf-die
1552 Renamed from "show debug dwarf2-die".
1554 set debug dwarf-read
1555 Renamed from "set debug dwarf2-read".
1556 show debug dwarf-read
1557 Renamed from "show debug dwarf2-read".
1559 maint set dwarf always-disassemble
1560 Renamed from "maint set dwarf2 always-disassemble".
1561 maint show dwarf always-disassemble
1562 Renamed from "maint show dwarf2 always-disassemble".
1564 maint set dwarf max-cache-age
1565 Renamed from "maint set dwarf2 max-cache-age".
1566 maint show dwarf max-cache-age
1567 Renamed from "maint show dwarf2 max-cache-age".
1569 set debug dwarf-line
1570 show debug dwarf-line
1571 Control display of debugging info regarding DWARF line processing.
1574 show max-completions
1575 Set the maximum number of candidates to be considered during
1576 completion. The default value is 200. This limit allows GDB
1577 to avoid generating large completion lists, the computation of
1578 which can cause the debugger to become temporarily unresponsive.
1580 set history remove-duplicates
1581 show history remove-duplicates
1582 Control the removal of duplicate history entries.
1584 maint set symbol-cache-size
1585 maint show symbol-cache-size
1586 Control the size of the symbol cache.
1588 set|show record btrace bts buffer-size
1589 Set and show the size of the ring buffer used for branch tracing in
1591 The obtained size may differ from the requested size. Use "info
1592 record" to see the obtained buffer size.
1594 set debug linux-namespaces
1595 show debug linux-namespaces
1596 Control display of debugging info regarding Linux namespaces.
1598 set|show record btrace pt buffer-size
1599 Set and show the size of the ring buffer used for branch tracing in
1600 Intel Processor Trace format.
1601 The obtained size may differ from the requested size. Use "info
1602 record" to see the obtained buffer size.
1604 maint set|show btrace pt skip-pad
1605 Set and show whether PAD packets are skipped when computing the
1608 * The command 'thread apply all' can now support new option '-ascending'
1609 to call its specified command for all threads in ascending order.
1611 * Python/Guile scripting
1613 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1614 special section named `.debug_gdb_scripts'.
1616 * New remote packets
1618 qXfer:btrace-conf:read
1619 Return the branch trace configuration for the current thread.
1621 Qbtrace-conf:bts:size
1622 Set the requested ring buffer size for branch tracing in BTS format.
1625 Enable Intel Procesor Trace-based branch tracing for the current
1626 process. The remote stub reports support for this packet to GDB's
1629 Qbtrace-conf:pt:size
1630 Set the requested ring buffer size for branch tracing in Intel Processor
1634 Indicates a memory breakpoint instruction was executed, irrespective
1635 of whether it was GDB that planted the breakpoint or the breakpoint
1636 is hardcoded in the program. This is required for correct non-stop
1640 Indicates the target stopped for a hardware breakpoint. This is
1641 required for correct non-stop mode operation.
1644 Return information about files on the remote system.
1646 qXfer:exec-file:read
1647 Return the full absolute name of the file that was executed to
1648 create a process running on the remote system.
1651 Select the filesystem on which vFile: operations with filename
1652 arguments will operate. This is required for GDB to be able to
1653 access files on remote targets where the remote stub does not
1654 share a common filesystem with the inferior(s).
1657 Indicates that a fork system call was executed.
1660 Indicates that a vfork system call was executed.
1662 vforkdone stop reason
1663 Indicates that a vfork child of the specified process has executed
1664 an exec or exit, allowing the vfork parent to resume execution.
1666 fork-events and vfork-events features in qSupported
1667 The qSupported packet allows GDB to request support for fork and
1668 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1669 and the qSupported response can contain the corresponding
1670 'stubfeatures'. Set and show commands can be used to display
1671 whether these features are enabled.
1673 * Extended-remote fork events
1675 ** GDB now has support for fork events on extended-remote Linux
1676 targets. For targets with Linux kernels 2.5.60 and later, this
1677 enables follow-fork-mode and detach-on-fork for both fork and
1678 vfork, as well as fork and vfork catchpoints.
1680 * The info record command now shows the recording format and the
1681 branch tracing configuration for the current thread when using
1682 the btrace record target.
1683 For the BTS format, it shows the ring buffer size.
1685 * GDB now has support for DTrace USDT (Userland Static Defined
1686 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1688 * GDB now supports access to vector registers on S/390 GNU/Linux
1691 * Removed command line options
1693 -xdb HP-UX XDB compatibility mode.
1695 * Removed targets and native configurations
1697 HP/PA running HP-UX hppa*-*-hpux*
1698 Itanium running HP-UX ia64-*-hpux*
1700 * New configure options
1703 This configure option allows the user to build GDB with support for
1704 Intel Processor Trace (default: auto). This requires libipt.
1706 --with-libipt-prefix=PATH
1707 Specify the path to the version of libipt that GDB should use.
1708 $PATH/include should contain the intel-pt.h header and
1709 $PATH/lib should contain the libipt.so library.
1711 *** Changes in GDB 7.9.1
1715 ** Xmethods can now specify a result type.
1717 *** Changes in GDB 7.9
1719 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1723 ** You can now access frame registers from Python scripts.
1724 ** New attribute 'producer' for gdb.Symtab objects.
1725 ** gdb.Objfile objects have a new attribute "progspace",
1726 which is the gdb.Progspace object of the containing program space.
1727 ** gdb.Objfile objects have a new attribute "owner".
1728 ** gdb.Objfile objects have a new attribute "build_id",
1729 which is the build ID generated when the file was built.
1730 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1731 ** A new event "gdb.clear_objfiles" has been added, triggered when
1732 selecting a new file to debug.
1733 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1734 ** New function gdb.lookup_objfile.
1736 New events which are triggered when GDB modifies the state of the
1739 ** gdb.events.inferior_call_pre: Function call is about to be made.
1740 ** gdb.events.inferior_call_post: Function call has just been made.
1741 ** gdb.events.memory_changed: A memory location has been altered.
1742 ** gdb.events.register_changed: A register has been altered.
1744 * New Python-based convenience functions:
1746 ** $_caller_is(name [, number_of_frames])
1747 ** $_caller_matches(regexp [, number_of_frames])
1748 ** $_any_caller_is(name [, number_of_frames])
1749 ** $_any_caller_matches(regexp [, number_of_frames])
1751 * GDB now supports the compilation and injection of source code into
1752 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1753 to compile the source code to object code, and if successful, inject
1754 and execute that code within the current context of the inferior.
1755 Currently the C language is supported. The commands used to
1756 interface with this new feature are:
1758 compile code [-raw|-r] [--] [source code]
1759 compile file [-raw|-r] filename
1763 demangle [-l language] [--] name
1764 Demangle "name" in the specified language, or the current language
1765 if elided. This command is renamed from the "maint demangle" command.
1766 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1767 as "maint demangler-warning".
1769 queue-signal signal-name-or-number
1770 Queue a signal to be delivered to the thread when it is resumed.
1772 add-auto-load-scripts-directory directory
1773 Add entries to the list of directories from which to load auto-loaded
1776 maint print user-registers
1777 List all currently available "user" registers.
1779 compile code [-r|-raw] [--] [source code]
1780 Compile, inject, and execute in the inferior the executable object
1781 code produced by compiling the provided source code.
1783 compile file [-r|-raw] filename
1784 Compile and inject into the inferior the executable object code
1785 produced by compiling the source code stored in the filename
1788 * On resume, GDB now always passes the signal the program had stopped
1789 for to the thread the signal was sent to, even if the user changed
1790 threads before resuming. Previously GDB would often (but not
1791 always) deliver the signal to the thread that happens to be current
1794 * Conversely, the "signal" command now consistently delivers the
1795 requested signal to the current thread. GDB now asks for
1796 confirmation if the program had stopped for a signal and the user
1797 switched threads meanwhile.
1799 * "breakpoint always-inserted" modes "off" and "auto" merged.
1801 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1802 won't remove breakpoints from the target until all threads stop,
1803 even in non-stop mode. The "auto" mode has been removed, and "off"
1804 is now the default mode.
1808 set debug symbol-lookup
1809 show debug symbol-lookup
1810 Control display of debugging info regarding symbol lookup.
1814 ** The -list-thread-groups command outputs an exit-code field for
1815 inferiors that have exited.
1819 MIPS SDE mips*-sde*-elf*
1823 Support for these obsolete configurations has been removed.
1825 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1826 SGI Irix-5.x mips-*-irix5*
1827 SGI Irix-6.x mips-*-irix6*
1828 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1829 VAX running Ultrix vax-*-ultrix*
1831 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1832 and "assf"), have been removed. Use the "sharedlibrary" command, or
1833 its alias "share", instead.
1835 *** Changes in GDB 7.8
1837 * New command line options
1840 This is an alias for the --data-directory option.
1842 * GDB supports printing and modifying of variable length automatic arrays
1843 as specified in ISO C99.
1845 * The ARM simulator now supports instruction level tracing
1846 with or without disassembly.
1850 GDB now has support for scripting using Guile. Whether this is
1851 available is determined at configure time.
1852 Guile version 2.0 or greater is required.
1853 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1855 * New commands (for set/show, see "New options" below)
1859 Invoke CODE by passing it to the Guile interpreter.
1863 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1865 info auto-load guile-scripts [regexp]
1866 Print the list of automatically loaded Guile scripts.
1868 * The source command is now capable of sourcing Guile scripts.
1869 This feature is dependent on the debugger being built with Guile support.
1873 set print symbol-loading (off|brief|full)
1874 show print symbol-loading
1875 Control whether to print informational messages when loading symbol
1876 information for a file. The default is "full", but when debugging
1877 programs with large numbers of shared libraries the amount of output
1878 becomes less useful.
1880 set guile print-stack (none|message|full)
1881 show guile print-stack
1882 Show a stack trace when an error is encountered in a Guile script.
1884 set auto-load guile-scripts (on|off)
1885 show auto-load guile-scripts
1886 Control auto-loading of Guile script files.
1888 maint ada set ignore-descriptive-types (on|off)
1889 maint ada show ignore-descriptive-types
1890 Control whether the debugger should ignore descriptive types in Ada
1891 programs. The default is not to ignore the descriptive types. See
1892 the user manual for more details on descriptive types and the intended
1893 usage of this option.
1895 set auto-connect-native-target
1897 Control whether GDB is allowed to automatically connect to the
1898 native target for the run, attach, etc. commands when not connected
1899 to any target yet. See also "target native" below.
1901 set record btrace replay-memory-access (read-only|read-write)
1902 show record btrace replay-memory-access
1903 Control what memory accesses are allowed during replay.
1905 maint set target-async (on|off)
1906 maint show target-async
1907 This controls whether GDB targets operate in synchronous or
1908 asynchronous mode. Normally the default is asynchronous, if it is
1909 available; but this can be changed to more easily debug problems
1910 occurring only in synchronous mode.
1912 set mi-async (on|off)
1914 Control whether MI asynchronous mode is preferred. This supersedes
1915 "set target-async" of previous GDB versions.
1917 * "set target-async" is deprecated as a CLI option and is now an alias
1918 for "set mi-async" (only puts MI into async mode).
1920 * Background execution commands (e.g., "c&", "s&", etc.) are now
1921 possible ``out of the box'' if the target supports them. Previously
1922 the user would need to explicitly enable the possibility with the
1923 "set target-async on" command.
1925 * New features in the GDB remote stub, GDBserver
1927 ** New option --debug-format=option1[,option2,...] allows one to add
1928 additional text to each output. At present only timestamps
1929 are supported: --debug-format=timestamps.
1930 Timestamps can also be turned on with the
1931 "monitor set debug-format timestamps" command from GDB.
1933 * The 'record instruction-history' command now starts counting instructions
1934 at one. This also affects the instruction ranges reported by the
1935 'record function-call-history' command when given the /i modifier.
1937 * The command 'record function-call-history' supports a new modifier '/c' to
1938 indent the function names based on their call stack depth.
1939 The fields for the '/i' and '/l' modifier have been reordered.
1940 The source line range is now prefixed with 'at'.
1941 The instruction range is now prefixed with 'inst'.
1942 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1943 "record instruction-history" and "list" commands.
1945 * The ranges given as arguments to the 'record function-call-history' and
1946 'record instruction-history' commands are now inclusive.
1948 * The btrace record target now supports the 'record goto' command.
1949 For locations inside the execution trace, the back trace is computed
1950 based on the information stored in the execution trace.
1952 * The btrace record target supports limited reverse execution and replay.
1953 The target does not record data and therefore does not allow reading
1954 memory or registers.
1956 * The "catch syscall" command now works on s390*-linux* targets.
1958 * The "compare-sections" command is no longer specific to target
1959 remote. It now works with all targets.
1961 * All native targets are now consistently called "native".
1962 Consequently, the "target child", "target GNU", "target djgpp",
1963 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1964 commands have been replaced with "target native". The QNX/NTO port
1965 leaves the "procfs" target in place and adds a "native" target for
1966 consistency with other ports. The impact on users should be minimal
1967 as these commands previously either throwed an error, or were
1968 no-ops. The target's name is visible in the output of the following
1969 commands: "help target", "info target", "info files", "maint print
1972 * The "target native" command now connects to the native target. This
1973 can be used to launch native programs even when "set
1974 auto-connect-native-target" is set to off.
1976 * GDB now supports access to Intel MPX registers on GNU/Linux.
1978 * Support for Intel AVX-512 registers on GNU/Linux.
1979 Support displaying and modifying Intel AVX-512 registers
1980 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1982 * New remote packets
1984 qXfer:btrace:read's annex
1985 The qXfer:btrace:read packet supports a new annex 'delta' to read
1986 branch trace incrementally.
1990 ** Valid Python operations on gdb.Value objects representing
1991 structs/classes invoke the corresponding overloaded operators if
1993 ** New `Xmethods' feature in the Python API. Xmethods are
1994 additional methods or replacements for existing methods of a C++
1995 class. This feature is useful for those cases where a method
1996 defined in C++ source code could be inlined or optimized out by
1997 the compiler, making it unavailable to GDB.
2000 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2002 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2003 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2004 its alias "share", instead.
2006 * The commands "set remotebaud" and "show remotebaud" are no longer
2007 supported. Use "set serial baud" and "show serial baud" (respectively)
2012 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2013 target-async". The latter is left as a deprecated alias of the
2014 former for backward compatibility. If the target supports it,
2015 CLI background execution commands are now always possible by
2016 default, independently of whether the frontend stated a
2017 preference for asynchronous execution with "-gdb-set mi-async".
2018 Previously "-gdb-set target-async off" affected both MI execution
2019 commands and CLI execution commands.
2021 *** Changes in GDB 7.7
2023 * Improved support for process record-replay and reverse debugging on
2024 arm*-linux* targets. Support for thumb32 and syscall instruction
2025 recording has been added.
2027 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2029 * GDB now supports Fission DWP file format version 2.
2030 http://gcc.gnu.org/wiki/DebugFission
2032 * New convenience function "$_isvoid", to check whether an expression
2033 is void. A void expression is an expression where the type of the
2034 result is "void". For example, some convenience variables may be
2035 "void" when evaluated (e.g., "$_exitcode" before the execution of
2036 the program being debugged; or an undefined convenience variable).
2037 Another example, when calling a function whose return type is
2040 * The "maintenance print objfiles" command now takes an optional regexp.
2042 * The "catch syscall" command now works on arm*-linux* targets.
2044 * GDB now consistently shows "<not saved>" when printing values of
2045 registers the debug info indicates have not been saved in the frame
2046 and there's nowhere to retrieve them from
2047 (callee-saved/call-clobbered registers):
2052 (gdb) info registers rax
2055 Before, the former would print "<optimized out>", and the latter
2056 "*value not available*".
2058 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2063 ** Frame filters and frame decorators have been added.
2064 ** Temporary breakpoints are now supported.
2065 ** Line tables representation has been added.
2066 ** New attribute 'parent_type' for gdb.Field objects.
2067 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2068 ** New attribute 'name' for gdb.Type objects.
2072 Nios II ELF nios2*-*-elf
2073 Nios II GNU/Linux nios2*-*-linux
2074 Texas Instruments MSP430 msp430*-*-elf
2076 * Removed native configurations
2078 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2079 been removed. ELF variants of these configurations are kept supported.
2081 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2082 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2083 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2084 i[34567]86-*-openbsd3.[0-3]
2085 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2086 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2087 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2091 Like "catch throw", but catches a re-thrown exception.
2092 maint check-psymtabs
2093 Renamed from old "maint check-symtabs".
2095 Perform consistency checks on symtabs.
2096 maint expand-symtabs
2097 Expand symtabs matching an optional regexp.
2100 Display the details of GDB configure-time options.
2102 maint set|show per-command
2103 maint set|show per-command space
2104 maint set|show per-command time
2105 maint set|show per-command symtab
2106 Enable display of per-command gdb resource usage.
2108 remove-symbol-file FILENAME
2109 remove-symbol-file -a ADDRESS
2110 Remove a symbol file added via add-symbol-file. The file to remove
2111 can be identified by its filename or by an address that lies within
2112 the boundaries of this symbol file in memory.
2115 info exceptions REGEXP
2116 Display the list of Ada exceptions defined in the program being
2117 debugged. If provided, only the exceptions whose names match REGEXP
2122 set debug symfile off|on
2124 Control display of debugging info regarding reading symbol files and
2125 symbol tables within those files
2127 set print raw frame-arguments
2128 show print raw frame-arguments
2129 Set/show whether to print frame arguments in raw mode,
2130 disregarding any defined pretty-printers.
2132 set remote trace-status-packet
2133 show remote trace-status-packet
2134 Set/show the use of remote protocol qTStatus packet.
2138 Control display of debugging messages related to Nios II targets.
2142 Control whether target-assisted range stepping is enabled.
2144 set startup-with-shell
2145 show startup-with-shell
2146 Specifies whether Unix child processes are started via a shell or
2151 Use the target memory cache for accesses to the code segment. This
2152 improves performance of remote debugging (particularly disassembly).
2154 * You can now use a literal value 'unlimited' for options that
2155 interpret 0 or -1 as meaning "unlimited". E.g., "set
2156 trace-buffer-size unlimited" is now an alias for "set
2157 trace-buffer-size -1" and "set height unlimited" is now an alias for
2160 * The "set debug symtab-create" debugging option of GDB has been changed to
2161 accept a verbosity level. 0 means "off", 1 provides basic debugging
2162 output, and values of 2 or greater provides more verbose output.
2164 * New command-line options
2166 Display the details of GDB configure-time options.
2168 * The command 'tsave' can now support new option '-ctf' to save trace
2169 buffer in Common Trace Format.
2171 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2174 * GDB now implements the the C++ 'typeid' operator.
2176 * The new convenience variable $_exception holds the exception being
2177 thrown or caught at an exception-related catchpoint.
2179 * The exception-related catchpoints, like "catch throw", now accept a
2180 regular expression which can be used to filter exceptions by type.
2182 * The new convenience variable $_exitsignal is automatically set to
2183 the terminating signal number when the program being debugged dies
2184 due to an uncaught signal.
2188 ** All MI commands now accept an optional "--language" option.
2189 Support for this feature can be verified by using the "-list-features"
2190 command, which should contain "language-option".
2192 ** The new command -info-gdb-mi-command allows the user to determine
2193 whether a GDB/MI command is supported or not.
2195 ** The "^error" result record returned when trying to execute an undefined
2196 GDB/MI command now provides a variable named "code" whose content is the
2197 "undefined-command" error code. Support for this feature can be verified
2198 by using the "-list-features" command, which should contain
2199 "undefined-command-error-code".
2201 ** The -trace-save MI command can optionally save trace buffer in Common
2204 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2206 ** The command -data-list-register-values now accepts an optional
2207 "--skip-unavailable" option. When used, only the available registers
2210 ** The new command -trace-frame-collected dumps collected variables,
2211 computed expressions, tvars, memory and registers in a traceframe.
2213 ** The commands -stack-list-locals, -stack-list-arguments and
2214 -stack-list-variables now accept an option "--skip-unavailable".
2215 When used, only the available locals or arguments are displayed.
2217 ** The -exec-run command now accepts an optional "--start" option.
2218 When used, the command follows the same semantics as the "start"
2219 command, stopping the program's execution at the start of its
2220 main subprogram. Support for this feature can be verified using
2221 the "-list-features" command, which should contain
2222 "exec-run-start-option".
2224 ** The new commands -catch-assert and -catch-exceptions insert
2225 catchpoints stopping the program when Ada exceptions are raised.
2227 ** The new command -info-ada-exceptions provides the equivalent of
2228 the new "info exceptions" command.
2230 * New system-wide configuration scripts
2231 A GDB installation now provides scripts suitable for use as system-wide
2232 configuration scripts for the following systems:
2236 * GDB now supports target-assigned range stepping with remote targets.
2237 This improves the performance of stepping source lines by reducing
2238 the number of control packets from/to GDB. See "New remote packets"
2241 * GDB now understands the element 'tvar' in the XML traceframe info.
2242 It has the id of the collected trace state variables.
2244 * On S/390 targets that provide the transactional-execution feature,
2245 the program interruption transaction diagnostic block (TDB) is now
2246 represented as a number of additional "registers" in GDB.
2248 * New remote packets
2252 The vCont packet supports a new 'r' action, that tells the remote
2253 stub to step through an address range itself, without GDB
2254 involvemement at each single-step.
2256 qXfer:libraries-svr4:read's annex
2257 The previously unused annex of the qXfer:libraries-svr4:read packet
2258 is now used to support passing an argument list. The remote stub
2259 reports support for this argument list to GDB's qSupported query.
2260 The defined arguments are "start" and "prev", used to reduce work
2261 necessary for library list updating, resulting in significant
2264 * New features in the GDB remote stub, GDBserver
2266 ** GDBserver now supports target-assisted range stepping. Currently
2267 enabled on x86/x86_64 GNU/Linux targets.
2269 ** GDBserver now adds element 'tvar' in the XML in the reply to
2270 'qXfer:traceframe-info:read'. It has the id of the collected
2271 trace state variables.
2273 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2276 * New 'z' formatter for printing and examining memory, this displays the
2277 value as hexadecimal zero padded on the left to the size of the type.
2279 * GDB can now use Windows x64 unwinding data.
2281 * The "set remotebaud" command has been replaced by "set serial baud".
2282 Similarly, "show remotebaud" has been replaced by "show serial baud".
2283 The "set remotebaud" and "show remotebaud" commands are still available
2284 to provide backward compatibility with older versions of GDB.
2286 *** Changes in GDB 7.6
2288 * Target record has been renamed to record-full.
2289 Record/replay is now enabled with the "record full" command.
2290 This also affects settings that are associated with full record/replay
2291 that have been moved from "set/show record" to "set/show record full":
2293 set|show record full insn-number-max
2294 set|show record full stop-at-limit
2295 set|show record full memory-query
2297 * A new record target "record-btrace" has been added. The new target
2298 uses hardware support to record the control-flow of a process. It
2299 does not support replaying the execution, but it implements the
2300 below new commands for investigating the recorded execution log.
2301 This new recording method can be enabled using:
2305 The "record-btrace" target is only available on Intel Atom processors
2306 and requires a Linux kernel 2.6.32 or later.
2308 * Two new commands have been added for record/replay to give information
2309 about the recorded execution without having to replay the execution.
2310 The commands are only supported by "record btrace".
2312 record instruction-history prints the execution history at
2313 instruction granularity
2315 record function-call-history prints the execution history at
2316 function granularity
2318 * New native configurations
2320 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2321 FreeBSD/powerpc powerpc*-*-freebsd
2322 x86_64/Cygwin x86_64-*-cygwin*
2323 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2327 ARM AArch64 aarch64*-*-elf
2328 ARM AArch64 GNU/Linux aarch64*-*-linux
2329 Lynx 178 PowerPC powerpc-*-lynx*178
2330 x86_64/Cygwin x86_64-*-cygwin*
2331 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2333 * If the configured location of system.gdbinit file (as given by the
2334 --with-system-gdbinit option at configure time) is in the
2335 data-directory (as specified by --with-gdb-datadir at configure
2336 time) or in one of its subdirectories, then GDB will look for the
2337 system-wide init file in the directory specified by the
2338 --data-directory command-line option.
2340 * New command line options:
2342 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2343 other initialization files, unlike -nx which disables all of them.
2345 * Removed command line options
2347 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2350 * The 'ptype' and 'whatis' commands now accept an argument to control
2353 * 'info proc' now works on some core files.
2357 ** Vectors can be created with gdb.Type.vector.
2359 ** Python's atexit.register now works in GDB.
2361 ** Types can be pretty-printed via a Python API.
2363 ** Python 3 is now supported (in addition to Python 2.4 or later)
2365 ** New class gdb.Architecture exposes GDB's internal representation
2366 of architecture in the Python API.
2368 ** New method Frame.architecture returns the gdb.Architecture object
2369 corresponding to the frame's architecture.
2371 * New Python-based convenience functions:
2373 ** $_memeq(buf1, buf2, length)
2374 ** $_streq(str1, str2)
2376 ** $_regex(str, regex)
2378 * The 'cd' command now defaults to using '~' (the home directory) if not
2381 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2382 default for GCC since November 2000.
2384 * The command 'forward-search' can now be abbreviated as 'fo'.
2386 * The command 'info tracepoints' can now display 'installed on target'
2387 or 'not installed on target' for each non-pending location of tracepoint.
2389 * New configure options
2391 --enable-libmcheck/--disable-libmcheck
2392 By default, development versions are built with -lmcheck on hosts
2393 that support it, in order to help track memory corruption issues.
2394 Release versions, on the other hand, are built without -lmcheck
2395 by default. The --enable-libmcheck/--disable-libmcheck configure
2396 options allow the user to override that default.
2397 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2398 This configure option allows the user to build GDB with
2399 libbabeltrace using which GDB can read Common Trace Format data.
2401 * New commands (for set/show, see "New options" below)
2404 Catch signals. This is similar to "handle", but allows commands and
2405 conditions to be attached.
2408 List the BFDs known to GDB.
2410 python-interactive [command]
2412 Start a Python interactive prompt, or evaluate the optional command
2413 and print the result of expressions.
2416 "py" is a new alias for "python".
2418 enable type-printer [name]...
2419 disable type-printer [name]...
2420 Enable or disable type printers.
2424 ** For the Renesas Super-H architecture, the "regs" command has been removed
2425 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2430 set print type methods (on|off)
2431 show print type methods
2432 Control whether method declarations are displayed by "ptype".
2433 The default is to show them.
2435 set print type typedefs (on|off)
2436 show print type typedefs
2437 Control whether typedef definitions are displayed by "ptype".
2438 The default is to show them.
2440 set filename-display basename|relative|absolute
2441 show filename-display
2442 Control the way in which filenames is displayed.
2443 The default is "relative", which preserves previous behavior.
2445 set trace-buffer-size
2446 show trace-buffer-size
2447 Request target to change the size of trace buffer.
2449 set remote trace-buffer-size-packet auto|on|off
2450 show remote trace-buffer-size-packet
2451 Control the use of the remote protocol `QTBuffer:size' packet.
2455 Control display of debugging messages related to ARM AArch64.
2458 set debug coff-pe-read
2459 show debug coff-pe-read
2460 Control display of debugging messages related to reading of COFF/PE
2465 Control display of debugging messages related to Mach-O symbols
2468 set debug notification
2469 show debug notification
2470 Control display of debugging info for async remote notification.
2474 ** Command parameter changes are now notified using new async record
2475 "=cmd-param-changed".
2476 ** Trace frame changes caused by command "tfind" are now notified using
2477 new async record "=traceframe-changed".
2478 ** The creation, deletion and modification of trace state variables
2479 are now notified using new async records "=tsv-created",
2480 "=tsv-deleted" and "=tsv-modified".
2481 ** The start and stop of process record are now notified using new
2482 async record "=record-started" and "=record-stopped".
2483 ** Memory changes are now notified using new async record
2485 ** The data-disassemble command response will include a "fullname" field
2486 containing the absolute file name when source has been requested.
2487 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2488 command, to allow pattern filling of memory areas.
2489 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2490 library load/unload events.
2491 ** The response to breakpoint commands and breakpoint async records
2492 includes an "installed" field containing a boolean state about each
2493 non-pending tracepoint location is whether installed on target or not.
2494 ** Output of the "-trace-status" command includes a "trace-file" field
2495 containing the name of the trace file being examined. This field is
2496 optional, and only present when examining a trace file.
2497 ** The "fullname" field is now always present along with the "file" field,
2498 even if the file cannot be found by GDB.
2500 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2501 You must have the LZMA library available when configuring GDB for this
2502 feature to be enabled. For more information, see:
2503 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2505 * New remote packets
2508 Set the size of trace buffer. The remote stub reports support for this
2509 packet to gdb's qSupported query.
2512 Enable Branch Trace Store (BTS)-based branch tracing for the current
2513 thread. The remote stub reports support for this packet to gdb's
2517 Disable branch tracing for the current thread. The remote stub reports
2518 support for this packet to gdb's qSupported query.
2521 Read the traced branches for the current thread. The remote stub
2522 reports support for this packet to gdb's qSupported query.
2524 *** Changes in GDB 7.5
2526 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2527 for more x32 ABI info.
2529 * GDB now supports access to MIPS DSP registers on Linux targets.
2531 * GDB now supports debugging microMIPS binaries.
2533 * The "info os" command on GNU/Linux can now display information on
2534 several new classes of objects managed by the operating system:
2535 "info os procgroups" lists process groups
2536 "info os files" lists file descriptors
2537 "info os sockets" lists internet-domain sockets
2538 "info os shm" lists shared-memory regions
2539 "info os semaphores" lists semaphores
2540 "info os msg" lists message queues
2541 "info os modules" lists loaded kernel modules
2543 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2544 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2545 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2546 options and inspect the probe arguments using the new $_probe_arg family
2547 of convenience variables. You can obtain more information about SystemTap
2548 in <http://sourceware.org/systemtap/>.
2550 * GDB now supports reversible debugging on ARM, it allows you to
2551 debug basic ARM and THUMB instructions, and provides
2552 record/replay support.
2554 * The option "symbol-reloading" has been deleted as it is no longer used.
2558 ** GDB commands implemented in Python can now be put in command class
2561 ** The "maint set python print-stack on|off" is now deleted.
2563 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2564 apply "flag enum"-style pretty-printing to any enum.
2566 ** gdb.lookup_symbol can now work when there is no current frame.
2568 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2569 the source at which the symbol was defined.
2571 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2572 method 'value'. The former indicates whether the symbol needs a
2573 frame in order to compute its value, and the latter computes the
2576 ** A new method 'referenced_value' on gdb.Value objects which can
2577 dereference pointer as well as C++ reference values.
2579 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2580 which return the global and static blocks (as gdb.Block objects),
2581 of the underlying symbol table, respectively.
2583 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2584 object associated with a PC value.
2586 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2587 of the address range occupied by code for the current source line.
2589 * Go language support.
2590 GDB now supports debugging programs written in the Go programming
2593 * GDBserver now supports stdio connections.
2594 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2596 * The binary "gdbtui" can no longer be built or installed.
2597 Use "gdb -tui" instead.
2599 * GDB will now print "flag" enums specially. A flag enum is one where
2600 all the enumerator values have no bits in common when pairwise
2601 "and"ed. When printing a value whose type is a flag enum, GDB will
2602 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2603 (gdb) print (enum E) 3
2606 * The filename part of a linespec will now match trailing components
2607 of a source file name. For example, "break gcc/expr.c:1000" will
2608 now set a breakpoint in build/gcc/expr.c, but not
2609 build/libcpp/expr.c.
2611 * The "info proc" and "generate-core-file" commands will now also
2612 work on remote targets connected to GDBserver on Linux.
2614 * The command "info catch" has been removed. It has been disabled
2615 since December 2007.
2617 * The "catch exception" and "catch assert" commands now accept
2618 a condition at the end of the command, much like the "break"
2619 command does. For instance:
2621 (gdb) catch exception Constraint_Error if Barrier = True
2623 Previously, it was possible to add a condition to such catchpoints,
2624 but it had to be done as a second step, after the catchpoint had been
2625 created, using the "condition" command.
2627 * The "info static-tracepoint-marker" command will now also work on
2628 native Linux targets with in-process agent.
2630 * GDB can now set breakpoints on inlined functions.
2632 * The .gdb_index section has been updated to include symbols for
2633 inlined functions. GDB will ignore older .gdb_index sections by
2634 default, which could cause symbol files to be loaded more slowly
2635 until their .gdb_index sections can be recreated. The new command
2636 "set use-deprecated-index-sections on" will cause GDB to use any older
2637 .gdb_index sections it finds. This will restore performance, but the
2638 ability to set breakpoints on inlined functions will be lost in symbol
2639 files with older .gdb_index sections.
2641 The .gdb_index section has also been updated to record more information
2642 about each symbol. This speeds up the "info variables", "info functions"
2643 and "info types" commands when used with programs having the .gdb_index
2644 section, as well as speeding up debugging with shared libraries using
2645 the .gdb_index section.
2647 * Ada support for GDB/MI Variable Objects has been added.
2649 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2654 ** New command -info-os is the MI equivalent of "info os".
2656 ** Output logs ("set logging" and related) now include MI output.
2660 ** "set use-deprecated-index-sections on|off"
2661 "show use-deprecated-index-sections on|off"
2662 Controls the use of deprecated .gdb_index sections.
2664 ** "catch load" and "catch unload" can be used to stop when a shared
2665 library is loaded or unloaded, respectively.
2667 ** "enable count" can be used to auto-disable a breakpoint after
2670 ** "info vtbl" can be used to show the virtual method tables for
2671 C++ and Java objects.
2673 ** "explore" and its sub commands "explore value" and "explore type"
2674 can be used to recursively explore values and types of
2675 expressions. These commands are available only if GDB is
2676 configured with '--with-python'.
2678 ** "info auto-load" shows status of all kinds of auto-loaded files,
2679 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2680 sequences of commands files, "info auto-load python-scripts"
2681 shows status of auto-loading Python script files,
2682 "info auto-load local-gdbinit" shows status of loading init file
2683 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2684 status of inferior specific thread debugging shared library loading.
2686 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2687 and "show auto-load-scripts" commands have been deprecated, use their
2688 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2689 and "show auto-load python-scripts" counterparts instead.
2691 ** "dprintf location,format,args..." creates a dynamic printf, which
2692 is basically a breakpoint that does a printf and immediately
2693 resumes your program's execution, so it is like a printf that you
2694 can insert dynamically at runtime instead of at compiletime.
2696 ** "set print symbol"
2698 Controls whether GDB attempts to display the symbol, if any,
2699 corresponding to addresses it prints. This defaults to "on", but
2700 you can set it to "off" to restore GDB's previous behavior.
2702 * Deprecated commands
2704 ** For the Renesas Super-H architecture, the "regs" command has been
2705 deprecated, and "info all-registers" should be used instead.
2709 Renesas RL78 rl78-*-elf
2710 HP OpenVMS ia64 ia64-hp-openvms*
2712 * GDBserver supports evaluation of breakpoint conditions. When
2713 support is advertised by GDBserver, GDB may be told to send the
2714 breakpoint conditions in bytecode form to GDBserver. GDBserver
2715 will only report the breakpoint trigger to GDB when its condition
2720 set mips compression
2721 show mips compression
2722 Select the compressed ISA encoding used in functions that have no symbol
2723 information available. The encoding can be set to either of:
2726 and is updated automatically from ELF file flags if available.
2728 set breakpoint condition-evaluation
2729 show breakpoint condition-evaluation
2730 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2731 GDBserver ("target"). Default option "auto" chooses the most efficient
2733 This option can improve debugger efficiency depending on the speed of the
2737 Disable auto-loading globally.
2740 Show auto-loading setting of all kinds of auto-loaded files.
2742 set auto-load gdb-scripts on|off
2743 show auto-load gdb-scripts
2744 Control auto-loading of GDB canned sequences of commands files.
2746 set auto-load python-scripts on|off
2747 show auto-load python-scripts
2748 Control auto-loading of Python script files.
2750 set auto-load local-gdbinit on|off
2751 show auto-load local-gdbinit
2752 Control loading of init file (.gdbinit) from current directory.
2754 set auto-load libthread-db on|off
2755 show auto-load libthread-db
2756 Control auto-loading of inferior specific thread debugging shared library.
2758 set auto-load scripts-directory <dir1>[:<dir2>...]
2759 show auto-load scripts-directory
2760 Set a list of directories from which to load auto-loaded scripts.
2761 Automatically loaded Python scripts and GDB scripts are located in one
2762 of the directories listed by this option.
2763 The delimiter (':' above) may differ according to the host platform.
2765 set auto-load safe-path <dir1>[:<dir2>...]
2766 show auto-load safe-path
2767 Set a list of directories from which it is safe to auto-load files.
2768 The delimiter (':' above) may differ according to the host platform.
2770 set debug auto-load on|off
2771 show debug auto-load
2772 Control display of debugging info for auto-loading the files above.
2774 set dprintf-style gdb|call|agent
2776 Control the way in which a dynamic printf is performed; "gdb"
2777 requests a GDB printf command, while "call" causes dprintf to call a
2778 function in the inferior. "agent" requests that the target agent
2779 (such as GDBserver) do the printing.
2781 set dprintf-function <expr>
2782 show dprintf-function
2783 set dprintf-channel <expr>
2784 show dprintf-channel
2785 Set the function and optional first argument to the call when using
2786 the "call" style of dynamic printf.
2788 set disconnected-dprintf on|off
2789 show disconnected-dprintf
2790 Control whether agent-style dynamic printfs continue to be in effect
2791 after GDB disconnects.
2793 * New configure options
2795 --with-auto-load-dir
2796 Configure default value for the 'set auto-load scripts-directory'
2797 setting above. It defaults to '$debugdir:$datadir/auto-load',
2798 $debugdir representing global debugging info directories (available
2799 via 'show debug-file-directory') and $datadir representing GDB's data
2800 directory (available via 'show data-directory').
2802 --with-auto-load-safe-path
2803 Configure default value for the 'set auto-load safe-path' setting
2804 above. It defaults to the --with-auto-load-dir setting.
2806 --without-auto-load-safe-path
2807 Set 'set auto-load safe-path' to '/', effectively disabling this
2810 * New remote packets
2812 z0/z1 conditional breakpoints extension
2814 The z0/z1 breakpoint insertion packets have been extended to carry
2815 a list of conditional expressions over to the remote stub depending on the
2816 condition evaluation mode. The use of this extension can be controlled
2817 via the "set remote conditional-breakpoints-packet" command.
2821 Specify the signals which the remote stub may pass to the debugged
2822 program without GDB involvement.
2824 * New command line options
2826 --init-command=FILE, -ix Like --command, -x but execute it
2827 before loading inferior.
2828 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2829 execute it before loading inferior.
2831 *** Changes in GDB 7.4
2833 * GDB now handles ambiguous linespecs more consistently; the existing
2834 FILE:LINE support has been expanded to other types of linespecs. A
2835 breakpoint will now be set on all matching locations in all
2836 inferiors, and locations will be added or removed according to
2839 * GDB now allows you to skip uninteresting functions and files when
2840 stepping with the "skip function" and "skip file" commands.
2842 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2843 and "show remote hardware-watchpoint-length-limit". These allows to
2844 set or show the maximum length limit (in bytes) of a remote
2845 target hardware watchpoint.
2847 This allows e.g. to use "unlimited" hardware watchpoints with the
2848 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2849 watchpoints are slower than real hardware watchpoints but are
2850 significantly faster than gdb software watchpoints.
2854 ** The register_pretty_printer function in module gdb.printing now takes
2855 an optional `replace' argument. If True, the new printer replaces any
2858 ** The "maint set python print-stack on|off" command has been
2859 deprecated and will be deleted in GDB 7.5.
2860 A new command: "set python print-stack none|full|message" has
2861 replaced it. Additionally, the default for "print-stack" is
2862 now "message", which just prints the error message without
2865 ** A prompt substitution hook (prompt_hook) is now available to the
2868 ** A new Python module, gdb.prompt has been added to the GDB Python
2869 modules library. This module provides functionality for
2870 escape sequences in prompts (used by set/show
2871 extended-prompt). These escape sequences are replaced by their
2872 corresponding value.
2874 ** Python commands and convenience-functions located in
2875 'data-directory'/python/gdb/command and
2876 'data-directory'/python/gdb/function are now automatically loaded
2879 ** Blocks now provide four new attributes. global_block and
2880 static_block will return the global and static blocks
2881 respectively. is_static and is_global are boolean attributes
2882 that indicate if the block is one of those two types.
2884 ** Symbols now provide the "type" attribute, the type of the symbol.
2886 ** The "gdb.breakpoint" function has been deprecated in favor of
2889 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2890 of a function. This class is based on the "finish" command
2891 available in the CLI.
2893 ** Type objects for struct and union types now allow access to
2894 the fields using standard Python dictionary (mapping) methods.
2895 For example, "some_type['myfield']" now works, as does
2896 "some_type.items()".
2898 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2901 ** A new function, "deep_items" has been added to the gdb.types
2902 module in the GDB Python modules library. This function returns
2903 an iterator over the fields of a struct or union type. Unlike
2904 the standard Python "iteritems" method, it will recursively traverse
2905 any anonymous fields.
2909 ** "*stopped" events can report several new "reason"s, such as
2912 ** Breakpoint changes are now notified using new async records, like
2913 "=breakpoint-modified".
2915 ** New command -ada-task-info.
2917 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2918 $sdir specifies the default system locations of shared libraries.
2919 $pdir specifies the directory where the libpthread used by the application
2922 GDB no longer looks in $sdir and $pdir after it has searched the directories
2923 mentioned in libthread-db-search-path. If you want to search those
2924 directories, they must be specified in libthread-db-search-path.
2925 The default value of libthread-db-search-path on GNU/Linux and Solaris
2926 systems is now "$sdir:$pdir".
2928 $pdir is not supported by gdbserver, it is currently ignored.
2929 $sdir is supported by gdbserver.
2931 * New configure option --with-iconv-bin.
2932 When using the internationalization support like the one in the GNU C
2933 library, GDB will invoke the "iconv" program to get a list of supported
2934 character sets. If this program lives in a non-standard location, one can
2935 use this option to specify where to find it.
2937 * When natively debugging programs on PowerPC BookE processors running
2938 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2939 watchpoints, which specify a mask in addition to an address to watch.
2940 The mask specifies that some bits of an address (the bits which are
2941 reset in the mask) should be ignored when matching the address accessed
2942 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2943 section in the user manual for more details.
2945 * The new option --once causes GDBserver to stop listening for connections once
2946 the first connection is made. The listening port used by GDBserver will
2947 become available after that.
2949 * New commands "info macros" and "alias" have been added.
2951 * New function parameters suffix @entry specifies value of function parameter
2952 at the time the function got called. Entry values are available only since
2958 "!" is now an alias of the "shell" command.
2959 Note that no space is needed between "!" and SHELL COMMAND.
2963 watch EXPRESSION mask MASK_VALUE
2964 The watch command now supports the mask argument which allows creation
2965 of masked watchpoints, if the current architecture supports this feature.
2967 info auto-load-scripts [REGEXP]
2968 This command was formerly named "maintenance print section-scripts".
2969 It is now generally useful and is no longer a maintenance-only command.
2971 info macro [-all] [--] MACRO
2972 The info macro command has new options `-all' and `--'. The first for
2973 printing all definitions of a macro. The second for explicitly specifying
2974 the end of arguments and the beginning of the macro name in case the macro
2975 name starts with a hyphen.
2977 collect[/s] EXPRESSIONS
2978 The tracepoint collect command now takes an optional modifier "/s"
2979 that directs it to dereference pointer-to-character types and
2980 collect the bytes of memory up to a zero byte. The behavior is
2981 similar to what you see when you use the regular print command on a
2982 string. An optional integer following the "/s" sets a bound on the
2983 number of bytes that will be collected.
2986 The trace start command now interprets any supplied arguments as a
2987 note to be recorded with the trace run, with an effect similar to
2988 setting the variable trace-notes.
2991 The trace stop command now interprets any arguments as a note to be
2992 mentioned along with the tstatus report that the trace was stopped
2993 with a command. The effect is similar to setting the variable
2996 * Tracepoints can now be enabled and disabled at any time after a trace
2997 experiment has been started using the standard "enable" and "disable"
2998 commands. It is now possible to start a trace experiment with no enabled
2999 tracepoints; GDB will display a warning, but will allow the experiment to
3000 begin, assuming that tracepoints will be enabled as needed while the trace
3003 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3004 locations with 4-byte instructions, when they were previously
3005 limited to locations with instructions of 5 bytes or longer.
3009 set debug dwarf2-read
3010 show debug dwarf2-read
3011 Turns on or off display of debugging messages related to reading
3012 DWARF debug info. The default is off.
3014 set debug symtab-create
3015 show debug symtab-create
3016 Turns on or off display of debugging messages related to symbol table
3017 creation. The default is off.
3020 show extended-prompt
3021 Set the GDB prompt, and allow escape sequences to be inserted to
3022 display miscellaneous information (see 'help set extended-prompt'
3023 for the list of sequences). This prompt (and any information
3024 accessed through the escape sequences) is updated every time the
3025 prompt is displayed.
3027 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3028 show print entry-values
3029 Set printing of frame argument values at function entry. In some cases
3030 GDB can determine the value of function argument which was passed by the
3031 function caller, even if the value was modified inside the called function.
3033 set debug entry-values
3034 show debug entry-values
3035 Control display of debugging info for determining frame argument values at
3036 function entry and virtual tail call frames.
3038 set basenames-may-differ
3039 show basenames-may-differ
3040 Set whether a source file may have multiple base names.
3041 (A "base name" is the name of a file with the directory part removed.
3042 Example: The base name of "/home/user/hello.c" is "hello.c".)
3043 If set, GDB will canonicalize file names (e.g., expand symlinks)
3044 before comparing them. Canonicalization is an expensive operation,
3045 but it allows the same file be known by more than one base name.
3046 If not set (the default), all source files are assumed to have just
3047 one base name, and gdb will do file name comparisons more efficiently.
3053 Set a user name and notes for the current and any future trace runs.
3054 This is useful for long-running and/or disconnected traces, to
3055 inform others (or yourself) as to who is running the trace, supply
3056 contact information, or otherwise explain what is going on.
3058 set trace-stop-notes
3059 show trace-stop-notes
3060 Set a note attached to the trace run, that is displayed when the
3061 trace has been stopped by a tstop command. This is useful for
3062 instance as an explanation, if you are stopping a trace run that was
3063 started by someone else.
3065 * New remote packets
3069 Dynamically enable a tracepoint in a started trace experiment.
3073 Dynamically disable a tracepoint in a started trace experiment.
3077 Set the user and notes of the trace run.
3081 Query the current status of a tracepoint.
3085 Query the minimum length of instruction at which a fast tracepoint may
3088 * Dcache size (number of lines) and line-size are now runtime-configurable
3089 via "set dcache line" and "set dcache line-size" commands.
3093 Texas Instruments TMS320C6x tic6x-*-*
3097 Renesas RL78 rl78-*-elf
3099 *** Changes in GDB 7.3.1
3101 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3103 *** Changes in GDB 7.3
3105 * GDB has a new command: "thread find [REGEXP]".
3106 It finds the thread id whose name, target id, or thread extra info
3107 matches the given regular expression.
3109 * The "catch syscall" command now works on mips*-linux* targets.
3111 * The -data-disassemble MI command now supports modes 2 and 3 for
3112 dumping the instruction opcodes.
3114 * New command line options
3116 -data-directory DIR Specify DIR as the "data-directory".
3117 This is mostly for testing purposes.
3119 * The "maint set python auto-load on|off" command has been renamed to
3120 "set auto-load-scripts on|off".
3122 * GDB has a new command: "set directories".
3123 It is like the "dir" command except that it replaces the
3124 source path list instead of augmenting it.
3126 * GDB now understands thread names.
3128 On GNU/Linux, "info threads" will display the thread name as set by
3129 prctl or pthread_setname_np.
3131 There is also a new command, "thread name", which can be used to
3132 assign a name internally for GDB to display.
3135 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3136 has been integrated into GDB.
3140 ** The function gdb.Write now accepts an optional keyword 'stream'.
3141 This keyword, when provided, will direct the output to either
3142 stdout, stderr, or GDB's logging output.
3144 ** Parameters can now be be sub-classed in Python, and in particular
3145 you may implement the get_set_doc and get_show_doc functions.
3146 This improves how Parameter set/show documentation is processed
3147 and allows for more dynamic content.
3149 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3150 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3151 have an is_valid method.
3153 ** Breakpoints can now be sub-classed in Python, and in particular
3154 you may implement a 'stop' function that is executed each time
3155 the inferior reaches that breakpoint.
3157 ** New function gdb.lookup_global_symbol looks up a global symbol.
3159 ** GDB values in Python are now callable if the value represents a
3160 function. For example, if 'some_value' represents a function that
3161 takes two integer parameters and returns a value, you can call
3162 that function like so:
3164 result = some_value (10,20)
3166 ** Module gdb.types has been added.
3167 It contains a collection of utilities for working with gdb.Types objects:
3168 get_basic_type, has_field, make_enum_dict.
3170 ** Module gdb.printing has been added.
3171 It contains utilities for writing and registering pretty-printers.
3172 New classes: PrettyPrinter, SubPrettyPrinter,
3173 RegexpCollectionPrettyPrinter.
3174 New function: register_pretty_printer.
3176 ** New commands "info pretty-printers", "enable pretty-printer" and
3177 "disable pretty-printer" have been added.
3179 ** gdb.parameter("directories") is now available.
3181 ** New function gdb.newest_frame returns the newest frame in the
3184 ** The gdb.InferiorThread class has a new "name" attribute. This
3185 holds the thread's name.
3187 ** Python Support for Inferior events.
3188 Python scripts can add observers to be notified of events
3189 occurring in the process being debugged.
3190 The following events are currently supported:
3191 - gdb.events.cont Continue event.
3192 - gdb.events.exited Inferior exited event.
3193 - gdb.events.stop Signal received, and Breakpoint hit events.
3197 ** GDB now puts template parameters in scope when debugging in an
3198 instantiation. For example, if you have:
3200 template<int X> int func (void) { return X; }
3202 then if you step into func<5>, "print X" will show "5". This
3203 feature requires proper debuginfo support from the compiler; it
3204 was added to GCC 4.5.
3206 ** The motion commands "next", "finish", "until", and "advance" now
3207 work better when exceptions are thrown. In particular, GDB will
3208 no longer lose control of the inferior; instead, the GDB will
3209 stop the inferior at the point at which the exception is caught.
3210 This functionality requires a change in the exception handling
3211 code that was introduced in GCC 4.5.
3213 * GDB now follows GCC's rules on accessing volatile objects when
3214 reading or writing target state during expression evaluation.
3215 One notable difference to prior behavior is that "print x = 0"
3216 no longer generates a read of x; the value of the assignment is
3217 now always taken directly from the value being assigned.
3219 * GDB now has some support for using labels in the program's source in
3220 linespecs. For instance, you can use "advance label" to continue
3221 execution to a label.
3223 * GDB now has support for reading and writing a new .gdb_index
3224 section. This section holds a fast index of DWARF debugging
3225 information and can be used to greatly speed up GDB startup and
3226 operation. See the documentation for `save gdb-index' for details.
3228 * The "watch" command now accepts an optional "-location" argument.
3229 When used, this causes GDB to watch the memory referred to by the
3230 expression. Such a watchpoint is never deleted due to it going out
3233 * GDB now supports thread debugging of core dumps on GNU/Linux.
3235 GDB now activates thread debugging using the libthread_db library
3236 when debugging GNU/Linux core dumps, similarly to when debugging
3237 live processes. As a result, when debugging a core dump file, GDB
3238 is now able to display pthread_t ids of threads. For example, "info
3239 threads" shows the same output as when debugging the process when it
3240 was live. In earlier releases, you'd see something like this:
3243 * 1 LWP 6780 main () at main.c:10
3245 While now you see this:
3248 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3250 It is also now possible to inspect TLS variables when debugging core
3253 When debugging a core dump generated on a machine other than the one
3254 used to run GDB, you may need to point GDB at the correct
3255 libthread_db library with the "set libthread-db-search-path"
3256 command. See the user manual for more details on this command.
3258 * When natively debugging programs on PowerPC BookE processors running
3259 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3260 which stop execution of the inferior whenever it executes an instruction
3261 at any address within the specified range. See the "PowerPC Embedded"
3262 section in the user manual for more details.
3264 * New features in the GDB remote stub, GDBserver
3266 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3267 and i686 LynxOS (version 5.x).
3269 ** GDBserver is now supported on Blackfin Linux.
3271 * New native configurations
3273 ia64 HP-UX ia64-*-hpux*
3277 Analog Devices, Inc. Blackfin Processor bfin-*
3279 * Ada task switching is now supported on sparc-elf targets when
3280 debugging a program using the Ravenscar Profile. For more information,
3281 see the "Tasking Support when using the Ravenscar Profile" section
3282 in the GDB user manual.
3284 * Guile support was removed.
3286 * New features in the GNU simulator
3288 ** The --map-info flag lists all known core mappings.
3290 ** CFI flashes may be simulated via the "cfi" device.
3292 *** Changes in GDB 7.2
3294 * Shared library support for remote targets by default
3296 When GDB is configured for a generic, non-OS specific target, like
3297 for example, --target=arm-eabi or one of the many *-*-elf targets,
3298 GDB now queries remote stubs for loaded shared libraries using the
3299 `qXfer:libraries:read' packet. Previously, shared library support
3300 was always disabled for such configurations.
3304 ** Argument Dependent Lookup (ADL)
3306 In C++ ADL lookup directs function search to the namespaces of its
3307 arguments even if the namespace has not been imported.
3317 Here the compiler will search for `foo' in the namespace of 'b'
3318 and find A::foo. GDB now supports this. This construct is commonly
3319 used in the Standard Template Library for operators.
3321 ** Improved User Defined Operator Support
3323 In addition to member operators, GDB now supports lookup of operators
3324 defined in a namespace and imported with a `using' directive, operators
3325 defined in the global scope, operators imported implicitly from an
3326 anonymous namespace, and the ADL operators mentioned in the previous
3328 GDB now also supports proper overload resolution for all the previously
3329 mentioned flavors of operators.
3331 ** static const class members
3333 Printing of static const class members that are initialized in the
3334 class definition has been fixed.
3336 * Windows Thread Information Block access.
3338 On Windows targets, GDB now supports displaying the Windows Thread
3339 Information Block (TIB) structure. This structure is visible either
3340 by using the new command `info w32 thread-information-block' or, by
3341 dereferencing the new convenience variable named `$_tlb', a
3342 thread-specific pointer to the TIB. This feature is also supported
3343 when remote debugging using GDBserver.
3345 * Static tracepoints
3347 Static tracepoints are calls in the user program into a tracing
3348 library. One such library is a port of the LTTng kernel tracer to
3349 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3350 When debugging with GDBserver, GDB now supports combining the GDB
3351 tracepoint machinery with such libraries. For example: the user can
3352 use GDB to probe a static tracepoint marker (a call from the user
3353 program into the tracing library) with the new "strace" command (see
3354 "New commands" below). This creates a "static tracepoint" in the
3355 breakpoint list, that can be manipulated with the same feature set
3356 as fast and regular tracepoints. E.g., collect registers, local and
3357 global variables, collect trace state variables, and define
3358 tracepoint conditions. In addition, the user can collect extra
3359 static tracepoint marker specific data, by collecting the new
3360 $_sdata internal variable. When analyzing the trace buffer, you can
3361 inspect $_sdata like any other variable available to GDB. For more
3362 information, see the "Tracepoints" chapter in GDB user manual. New
3363 remote packets have been defined to support static tracepoints, see
3364 the "New remote packets" section below.
3366 * Better reconstruction of tracepoints after disconnected tracing
3368 GDB will attempt to download the original source form of tracepoint
3369 definitions when starting a trace run, and then will upload these
3370 upon reconnection to the target, resulting in a more accurate
3371 reconstruction of the tracepoints that are in use on the target.
3375 You can now exercise direct control over the ways that GDB can
3376 affect your program. For instance, you can disallow the setting of
3377 breakpoints, so that the program can run continuously (assuming
3378 non-stop mode). In addition, the "observer" variable is available
3379 to switch all of the different controls; in observer mode, GDB
3380 cannot affect the target's behavior at all, which is useful for
3381 tasks like diagnosing live systems in the field.
3383 * The new convenience variable $_thread holds the number of the
3386 * New remote packets
3390 Return the address of the Windows Thread Information Block of a given thread.
3394 In response to several of the tracepoint packets, the target may now
3395 also respond with a number of intermediate `qRelocInsn' request
3396 packets before the final result packet, to have GDB handle
3397 relocating an instruction to execute at a different address. This
3398 is particularly useful for stubs that support fast tracepoints. GDB
3399 reports support for this feature in the qSupported packet.
3403 List static tracepoint markers in the target program.
3407 List static tracepoint markers at a given address in the target
3410 qXfer:statictrace:read
3412 Read the static trace data collected (by a `collect $_sdata'
3413 tracepoint action). The remote stub reports support for this packet
3414 to gdb's qSupported query.
3418 Send the current settings of GDB's permission flags.
3422 Send part of the source (textual) form of a tracepoint definition,
3423 which includes location, conditional, and action list.
3425 * The source command now accepts a -s option to force searching for the
3426 script in the source search path even if the script name specifies
3429 * New features in the GDB remote stub, GDBserver
3431 - GDBserver now support tracepoints (including fast tracepoints, and
3432 static tracepoints). The feature is currently supported by the
3433 i386-linux and amd64-linux builds. See the "Tracepoints support
3434 in gdbserver" section in the manual for more information.
3436 GDBserver JIT compiles the tracepoint's conditional agent
3437 expression bytecode into native code whenever possible for low
3438 overhead dynamic tracepoints conditionals. For such tracepoints,
3439 an expression that examines program state is evaluated when the
3440 tracepoint is reached, in order to determine whether to capture
3441 trace data. If the condition is simple and false, processing the
3442 tracepoint finishes very quickly and no data is gathered.
3444 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3445 for static tracepoints support.
3447 - GDBserver now supports x86_64 Windows 64-bit debugging.
3449 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3450 it understands register description.
3452 * The --batch flag now disables pagination and queries.
3454 * X86 general purpose registers
3456 GDB now supports reading/writing byte, word and double-word x86
3457 general purpose registers directly. This means you can use, say,
3458 $ah or $ax to refer, respectively, to the byte register AH and
3459 16-bit word register AX that are actually portions of the 32-bit
3460 register EAX or 64-bit register RAX.
3462 * The `commands' command now accepts a range of breakpoints to modify.
3463 A plain `commands' following a command that creates multiple
3464 breakpoints affects all the breakpoints set by that command. This
3465 applies to breakpoints set by `rbreak', and also applies when a
3466 single `break' command creates multiple breakpoints (e.g.,
3467 breakpoints on overloaded c++ functions).
3469 * The `rbreak' command now accepts a filename specification as part of
3470 its argument, limiting the functions selected by the regex to those
3471 in the specified file.
3473 * Support for remote debugging Windows and SymbianOS shared libraries
3474 from Unix hosts has been improved. Non Windows GDB builds now can
3475 understand target reported file names that follow MS-DOS based file
3476 system semantics, such as file names that include drive letters and
3477 use the backslash character as directory separator. This makes it
3478 possible to transparently use the "set sysroot" and "set
3479 solib-search-path" on Unix hosts to point as host copies of the
3480 target's shared libraries. See the new command "set
3481 target-file-system-kind" described below, and the "Commands to
3482 specify files" section in the user manual for more information.
3486 eval template, expressions...
3487 Convert the values of one or more expressions under the control
3488 of the string template to a command line, and call it.
3490 set target-file-system-kind unix|dos-based|auto
3491 show target-file-system-kind
3492 Set or show the assumed file system kind for target reported file
3495 save breakpoints <filename>
3496 Save all current breakpoint definitions to a file suitable for use
3497 in a later debugging session. To read the saved breakpoint
3498 definitions, use the `source' command.
3500 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3503 info static-tracepoint-markers
3504 Display information about static tracepoint markers in the target.
3506 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3507 Define a static tracepoint by probing a marker at the given
3508 function, line, address, or marker ID.
3512 Enable and disable observer mode.
3514 set may-write-registers on|off
3515 set may-write-memory on|off
3516 set may-insert-breakpoints on|off
3517 set may-insert-tracepoints on|off
3518 set may-insert-fast-tracepoints on|off
3519 set may-interrupt on|off
3520 Set individual permissions for GDB effects on the target. Note that
3521 some of these settings can have undesirable or surprising
3522 consequences, particularly when changed in the middle of a session.
3523 For instance, disabling the writing of memory can prevent
3524 breakpoints from being inserted, cause single-stepping to fail, or
3525 even crash your program, if you disable after breakpoints have been
3526 inserted. However, GDB should not crash.
3528 set record memory-query on|off
3529 show record memory-query
3530 Control whether to stop the inferior if memory changes caused
3531 by an instruction cannot be recorded.
3536 The disassemble command now supports "start,+length" form of two arguments.
3540 ** GDB now provides a new directory location, called the python directory,
3541 where Python scripts written for GDB can be installed. The location
3542 of that directory is <data-directory>/python, where <data-directory>
3543 is the GDB data directory. For more details, see section `Scripting
3544 GDB using Python' in the manual.
3546 ** The GDB Python API now has access to breakpoints, symbols, symbol
3547 tables, program spaces, inferiors, threads and frame's code blocks.
3548 Additionally, GDB Parameters can now be created from the API, and
3549 manipulated via set/show in the CLI.
3551 ** New functions gdb.target_charset, gdb.target_wide_charset,
3552 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3554 ** New exception gdb.GdbError.
3556 ** Pretty-printers are now also looked up in the current program space.
3558 ** Pretty-printers can now be individually enabled and disabled.
3560 ** GDB now looks for names of Python scripts to auto-load in a
3561 special section named `.debug_gdb_scripts', in addition to looking
3562 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3564 * Tracepoint actions were unified with breakpoint commands. In particular,
3565 there are no longer differences in "info break" output for breakpoints and
3566 tracepoints and the "commands" command can be used for both tracepoints and
3567 regular breakpoints.
3571 ARM Symbian arm*-*-symbianelf*
3573 * D language support.
3574 GDB now supports debugging programs written in the D programming
3577 * GDB now supports the extended ptrace interface for PowerPC which is
3578 available since Linux kernel version 2.6.34. This automatically enables
3579 any hardware breakpoints and additional hardware watchpoints available in
3580 the processor. The old ptrace interface exposes just one hardware
3581 watchpoint and no hardware breakpoints.
3583 * GDB is now able to use the Data Value Compare (DVC) register available on
3584 embedded PowerPC processors to implement in hardware simple watchpoint
3585 conditions of the form:
3587 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3589 This works in native GDB running on Linux kernels with the extended ptrace
3590 interface mentioned above.
3592 *** Changes in GDB 7.1
3596 ** Namespace Support
3598 GDB now supports importing of namespaces in C++. This enables the
3599 user to inspect variables from imported namespaces. Support for
3600 namepace aliasing has also been added. So, if a namespace is
3601 aliased in the current scope (e.g. namepace C=A; ) the user can
3602 print variables using the alias (e.g. (gdb) print C::x).
3606 All known bugs relating to the printing of virtual base class were
3607 fixed. It is now possible to call overloaded static methods using a
3612 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3613 and reinterpret_cast<> are now handled by the C++ expression parser.
3617 Xilinx MicroBlaze microblaze-*-*
3622 Xilinx MicroBlaze microblaze
3625 * Multi-program debugging.
3627 GDB now has support for multi-program (a.k.a. multi-executable or
3628 multi-exec) debugging. This allows for debugging multiple inferiors
3629 simultaneously each running a different program under the same GDB
3630 session. See "Debugging Multiple Inferiors and Programs" in the
3631 manual for more information. This implied some user visible changes
3632 in the multi-inferior support. For example, "info inferiors" now
3633 lists inferiors that are not running yet or that have exited
3634 already. See also "New commands" and "New options" below.
3636 * New tracing features
3638 GDB's tracepoint facility now includes several new features:
3640 ** Trace state variables
3642 GDB tracepoints now include support for trace state variables, which
3643 are variables managed by the target agent during a tracing
3644 experiment. They are useful for tracepoints that trigger each
3645 other, so for instance one tracepoint can count hits in a variable,
3646 and then a second tracepoint has a condition that is true when the
3647 count reaches a particular value. Trace state variables share the
3648 $-syntax of GDB convenience variables, and can appear in both
3649 tracepoint actions and condition expressions. Use the "tvariable"
3650 command to create, and "info tvariables" to view; see "Trace State
3651 Variables" in the manual for more detail.
3655 GDB now includes an option for defining fast tracepoints, which
3656 targets may implement more efficiently, such as by installing a jump
3657 into the target agent rather than a trap instruction. The resulting
3658 speedup can be by two orders of magnitude or more, although the
3659 tradeoff is that some program locations on some target architectures
3660 might not allow fast tracepoint installation, for instance if the
3661 instruction to be replaced is shorter than the jump. To request a
3662 fast tracepoint, use the "ftrace" command, with syntax identical to
3663 the regular trace command.
3665 ** Disconnected tracing
3667 It is now possible to detach GDB from the target while it is running
3668 a trace experiment, then reconnect later to see how the experiment
3669 is going. In addition, a new variable disconnected-tracing lets you
3670 tell the target agent whether to continue running a trace if the
3671 connection is lost unexpectedly.
3675 GDB now has the ability to save the trace buffer into a file, and
3676 then use that file as a target, similarly to you can do with
3677 corefiles. You can select trace frames, print data that was
3678 collected in them, and use tstatus to display the state of the
3679 tracing run at the moment that it was saved. To create a trace
3680 file, use "tsave <filename>", and to use it, do "target tfile
3683 ** Circular trace buffer
3685 You can ask the target agent to handle the trace buffer as a
3686 circular buffer, discarding the oldest trace frames to make room for
3687 newer ones, by setting circular-trace-buffer to on. This feature may
3688 not be available for all target agents.
3693 The disassemble command, when invoked with two arguments, now requires
3694 the arguments to be comma-separated.
3697 The info variables command now displays variable definitions. Files
3698 which only declare a variable are not shown.
3701 The source command is now capable of sourcing Python scripts.
3702 This feature is dependent on the debugger being build with Python
3705 Related to this enhancement is also the introduction of a new command
3706 "set script-extension" (see below).
3708 * New commands (for set/show, see "New options" below)
3710 record save [<FILENAME>]
3711 Save a file (in core file format) containing the process record
3712 execution log for replay debugging at a later time.
3714 record restore <FILENAME>
3715 Restore the process record execution log that was saved at an
3716 earlier time, for replay debugging.
3718 add-inferior [-copies <N>] [-exec <FILENAME>]
3721 clone-inferior [-copies <N>] [ID]
3722 Make a new inferior ready to execute the same program another
3723 inferior has loaded.
3728 maint info program-spaces
3729 List the program spaces loaded into GDB.
3731 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3732 show remote interrupt-sequence
3733 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3734 as the sequence to the remote target in order to interrupt the execution.
3735 Ctrl-C is a default. Some system prefers BREAK which is high level of
3736 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3737 Magic SysRq g. It is BREAK signal and character 'g'.
3739 set remote interrupt-on-connect [on | off]
3740 show remote interrupt-on-connect
3741 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3742 remote target when gdb connects to it. This is needed when you debug
3745 set remotebreak [on | off]
3747 Deprecated. Use "set/show remote interrupt-sequence" instead.
3749 tvariable $NAME [ = EXP ]
3750 Create or modify a trace state variable.
3753 List trace state variables and their values.
3755 delete tvariable $NAME ...
3756 Delete one or more trace state variables.
3759 Evaluate the given expressions without collecting anything into the
3760 trace buffer. (Valid in tracepoint actions only.)
3762 ftrace FN / FILE:LINE / *ADDR
3763 Define a fast tracepoint at the given function, line, or address.
3765 * New expression syntax
3767 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3768 GDB now parses 0b101010 identically with 42.
3772 set follow-exec-mode new|same
3773 show follow-exec-mode
3774 Control whether GDB reuses the same inferior across an exec call or
3775 creates a new one. This is useful to be able to restart the old
3776 executable after the inferior having done an exec call.
3778 set default-collect EXPR, ...
3779 show default-collect
3780 Define a list of expressions to be collected at each tracepoint.
3781 This is a useful way to ensure essential items are not overlooked,
3782 such as registers or a critical global variable.
3784 set disconnected-tracing
3785 show disconnected-tracing
3786 If set to 1, the target is instructed to continue tracing if it
3787 loses its connection to GDB. If 0, the target is to stop tracing
3790 set circular-trace-buffer
3791 show circular-trace-buffer
3792 If set to on, the target is instructed to use a circular trace buffer
3793 and discard the oldest trace frames instead of stopping the trace due
3794 to a full trace buffer. If set to off, the trace stops when the buffer
3795 fills up. Some targets may not support this.
3797 set script-extension off|soft|strict
3798 show script-extension
3799 If set to "off", the debugger does not perform any script language
3800 recognition, and all sourced files are assumed to be GDB scripts.
3801 If set to "soft" (the default), files are sourced according to
3802 filename extension, falling back to GDB scripts if the first
3804 If set to "strict", files are sourced according to filename extension.
3806 set ada trust-PAD-over-XVS on|off
3807 show ada trust-PAD-over-XVS
3808 If off, activate a workaround against a bug in the debugging information
3809 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3810 the GCC sources for more information about the GNAT encoding and
3811 PAD types in particular). It is always safe to set this option to
3812 off, but this introduces a slight performance penalty. The default
3815 * Python API Improvements
3817 ** GDB provides the new class gdb.LazyString. This is useful in
3818 some pretty-printing cases. The new method gdb.Value.lazy_string
3819 provides a simple way to create objects of this type.
3821 ** The fields returned by gdb.Type.fields now have an
3822 `is_base_class' attribute.
3824 ** The new method gdb.Type.range returns the range of an array type.
3826 ** The new method gdb.parse_and_eval can be used to parse and
3827 evaluate an expression.
3829 * New remote packets
3832 Define a trace state variable.
3835 Get the current value of a trace state variable.
3838 Set desired tracing behavior upon disconnection.
3841 Set the trace buffer to be linear or circular.
3844 Get data about the tracepoints currently in use.
3848 Process record now works correctly with hardware watchpoints.
3850 Multiple bug fixes have been made to the mips-irix port, making it
3851 much more reliable. In particular:
3852 - Debugging threaded applications is now possible again. Previously,
3853 GDB would hang while starting the program, or while waiting for
3854 the program to stop at a breakpoint.
3855 - Attaching to a running process no longer hangs.
3856 - An error occurring while loading a core file has been fixed.
3857 - Changing the value of the PC register now works again. This fixes
3858 problems observed when using the "jump" command, or when calling
3859 a function from GDB, or even when assigning a new value to $pc.
3860 - With the "finish" and "return" commands, the return value for functions
3861 returning a small array is now correctly printed.
3862 - It is now possible to break on shared library code which gets executed
3863 during a shared library init phase (code executed while executing
3864 their .init section). Previously, the breakpoint would have no effect.
3865 - GDB is now able to backtrace through the signal handler for
3866 non-threaded programs.
3868 PIE (Position Independent Executable) programs debugging is now supported.
3869 This includes debugging execution of PIC (Position Independent Code) shared
3870 libraries although for that, it should be possible to run such libraries as an
3873 *** Changes in GDB 7.0
3875 * GDB now has an interface for JIT compilation. Applications that
3876 dynamically generate code can create symbol files in memory and register
3877 them with GDB. For users, the feature should work transparently, and
3878 for JIT developers, the interface is documented in the GDB manual in the
3879 "JIT Compilation Interface" chapter.
3881 * Tracepoints may now be conditional. The syntax is as for
3882 breakpoints; either an "if" clause appended to the "trace" command,
3883 or the "condition" command is available. GDB sends the condition to
3884 the target for evaluation using the same bytecode format as is used
3885 for tracepoint actions.
3887 * The disassemble command now supports: an optional /r modifier, print the
3888 raw instructions in hex as well as in symbolic form, and an optional /m
3889 modifier to print mixed source+assembly.
3891 * Process record and replay
3893 In a architecture environment that supports ``process record and
3894 replay'', ``process record and replay'' target can record a log of
3895 the process execution, and replay it with both forward and reverse
3898 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3899 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3900 set execution-direction {forward|reverse}, for targets that support
3903 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3904 feature is available with a native GDB running on kernel version
3907 * GDB now has support for multi-byte and wide character sets on the
3908 target. Strings whose character type is wchar_t, char16_t, or
3909 char32_t are now correctly printed. GDB supports wide- and unicode-
3910 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3911 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3912 `printf'. This feature requires iconv to work properly; if your
3913 system does not have a working iconv, GDB can use GNU libiconv. See
3914 the installation instructions for more information.
3916 * GDB now supports automatic retrieval of shared library files from
3917 remote targets. To use this feature, specify a system root that begins
3918 with the `remote:' prefix, either via the `set sysroot' command or via
3919 the `--with-sysroot' configure-time option.
3921 * "info sharedlibrary" now takes an optional regex of libraries to show,
3922 and it now reports if a shared library has no debugging information.
3924 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3925 now complete on file names.
3927 * When completing in expressions, gdb will attempt to limit
3928 completions to allowable structure or union fields, where appropriate.
3929 For instance, consider:
3931 # struct example { int f1; double f2; };
3932 # struct example variable;
3935 If the user types TAB at the end of this command line, the available
3936 completions will be "f1" and "f2".
3938 * Inlined functions are now supported. They show up in backtraces, and
3939 the "step", "next", and "finish" commands handle them automatically.
3941 * GDB now supports the token-splicing (##) and stringification (#)
3942 operators when expanding macros. It also supports variable-arity
3945 * GDB now supports inspecting extra signal information, exported by
3946 the new $_siginfo convenience variable. The feature is currently
3947 implemented on linux ARM, i386 and amd64.
3949 * GDB can now display the VFP floating point registers and NEON vector
3950 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3951 can provide these registers (requires Linux 2.6.30 or later). Remote
3952 and simulator targets may also provide them.
3954 * New remote packets
3957 Search memory for a sequence of bytes.
3960 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3961 operation over reliable transport links. Use of this packet is
3962 controlled by the `set remote noack-packet' command.
3965 Kill the process with the specified process ID. Use this in preference
3966 to `k' when multiprocess protocol extensions are supported.
3969 Obtains additional operating system information
3973 Read or write additional signal information.
3975 * Removed remote protocol undocumented extension
3977 An undocumented extension to the remote protocol's `S' stop reply
3978 packet that permited the stub to pass a process id was removed.
3979 Remote servers should use the `T' stop reply packet instead.
3981 * GDB now supports multiple function calling conventions according to the
3982 DWARF-2 DW_AT_calling_convention function attribute.
3984 * The SH target utilizes the aforementioned change to distinguish between gcc
3985 and Renesas calling convention. It also adds the new CLI commands
3986 `set/show sh calling-convention'.
3988 * GDB can now read compressed debug sections, as produced by GNU gold
3989 with the --compress-debug-sections=zlib flag.
3991 * 64-bit core files are now supported on AIX.
3993 * Thread switching is now supported on Tru64.
3995 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3996 which will be allocated using malloc later in program execution.
3998 * The qXfer:libraries:read remote procotol packet now allows passing a
3999 list of section offsets.
4001 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4002 conditions handling signals delivered during attach or thread creation
4003 have also been fixed.
4005 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4006 From the user's standpoint, all unqualified instances of True and False
4007 are treated as the standard definitions, regardless of context.
4009 * GDB now parses C++ symbol and type names more flexibly. For
4012 template<typename T> class C { };
4015 GDB will now correctly handle all of:
4017 ptype C<char const *>
4018 ptype C<char const*>
4019 ptype C<const char *>
4020 ptype C<const char*>
4022 * New features in the GDB remote stub, gdbserver
4024 - The "--wrapper" command-line argument tells gdbserver to use a
4025 wrapper program to launch programs for debugging.
4027 - On PowerPC and S/390 targets, it is now possible to use a single
4028 gdbserver executable to debug both 32-bit and 64-bit programs.
4029 (This requires gdbserver itself to be built as a 64-bit executable.)
4031 - gdbserver uses the new noack protocol mode for TCP connections to
4032 reduce communications latency, if also supported and enabled in GDB.
4034 - Support for the sparc64-linux-gnu target is now included in
4037 - The amd64-linux build of gdbserver now supports debugging both
4038 32-bit and 64-bit programs.
4040 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4041 now support hardware watchpoints, and will use them automatically
4046 GDB now has support for scripting using Python. Whether this is
4047 available is determined at configure time.
4049 New GDB commands can now be written in Python.
4051 * Ada tasking support
4053 Ada tasks can now be inspected in GDB. The following commands have
4057 Print the list of Ada tasks.
4059 Print detailed information about task number N.
4061 Print the task number of the current task.
4063 Switch the context of debugging to task number N.
4065 * Support for user-defined prefixed commands. The "define" command can
4066 add new commands to existing prefixes, e.g. "target".
4068 * Multi-inferior, multi-process debugging.
4070 GDB now has generalized support for multi-inferior debugging. See
4071 "Debugging Multiple Inferiors" in the manual for more information.
4072 Although availability still depends on target support, the command
4073 set is more uniform now. The GNU/Linux specific multi-forks support
4074 has been migrated to this new framework. This implied some user
4075 visible changes; see "New commands" and also "Removed commands"
4078 * Target descriptions can now describe the target OS ABI. See the
4079 "Target Description Format" section in the user manual for more
4082 * Target descriptions can now describe "compatible" architectures
4083 to indicate that the target can execute applications for a different
4084 architecture in addition to those for the main target architecture.
4085 See the "Target Description Format" section in the user manual for
4088 * Multi-architecture debugging.
4090 GDB now includes general supports for debugging applications on
4091 hybrid systems that use more than one single processor architecture
4092 at the same time. Each such hybrid architecture still requires
4093 specific support to be added. The only hybrid architecture supported
4094 in this version of GDB is the Cell Broadband Engine.
4096 * GDB now supports integrated debugging of Cell/B.E. applications that
4097 use both the PPU and SPU architectures. To enable support for hybrid
4098 Cell/B.E. debugging, you need to configure GDB to support both the
4099 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4100 --enable-targets configure option.
4102 * Non-stop mode debugging.
4104 For some targets, GDB now supports an optional mode of operation in
4105 which you can examine stopped threads while other threads continue
4106 to execute freely. This is referred to as non-stop mode, with the
4107 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4108 section in the user manual for more information.
4110 To be able to support remote non-stop debugging, a remote stub needs
4111 to implement the non-stop mode remote protocol extensions, as
4112 described in the "Remote Non-Stop" section of the user manual. The
4113 GDB remote stub, gdbserver, has been adjusted to support these
4114 extensions on linux targets.
4116 * New commands (for set/show, see "New options" below)
4118 catch syscall [NAME(S) | NUMBER(S)]
4119 Catch system calls. Arguments, which should be names of system
4120 calls or their numbers, mean catch only those syscalls. Without
4121 arguments, every syscall will be caught. When the inferior issues
4122 any of the specified syscalls, GDB will stop and announce the system
4123 call, both when it is called and when its call returns. This
4124 feature is currently available with a native GDB running on the
4125 Linux Kernel, under the following architectures: x86, x86_64,
4126 PowerPC and PowerPC64.
4128 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4130 Search memory for a sequence of bytes.
4132 maint set python print-stack
4133 maint show python print-stack
4134 Show a stack trace when an error is encountered in a Python script.
4137 Invoke CODE by passing it to the Python interpreter.
4142 These allow macros to be defined, undefined, and listed
4146 Show operating system information about processes.
4149 List the inferiors currently under GDB's control.
4152 Switch focus to inferior number NUM.
4155 Detach from inferior number NUM.
4158 Kill inferior number NUM.
4162 set spu stop-on-load
4163 show spu stop-on-load
4164 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4166 set spu auto-flush-cache
4167 show spu auto-flush-cache
4168 Control whether to automatically flush the software-managed cache
4169 during Cell/B.E. debugging.
4171 set sh calling-convention
4172 show sh calling-convention
4173 Control the calling convention used when calling SH target functions.
4176 show debug timestamp
4177 Control display of timestamps with GDB debugging output.
4179 set disassemble-next-line
4180 show disassemble-next-line
4181 Control display of disassembled source lines or instructions when
4184 set remote noack-packet
4185 show remote noack-packet
4186 Set/show the use of remote protocol QStartNoAckMode packet. See above
4187 under "New remote packets."
4189 set remote query-attached-packet
4190 show remote query-attached-packet
4191 Control use of remote protocol `qAttached' (query-attached) packet.
4193 set remote read-siginfo-object
4194 show remote read-siginfo-object
4195 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4198 set remote write-siginfo-object
4199 show remote write-siginfo-object
4200 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4203 set remote reverse-continue
4204 show remote reverse-continue
4205 Control use of remote protocol 'bc' (reverse-continue) packet.
4207 set remote reverse-step
4208 show remote reverse-step
4209 Control use of remote protocol 'bs' (reverse-step) packet.
4211 set displaced-stepping
4212 show displaced-stepping
4213 Control displaced stepping mode. Displaced stepping is a way to
4214 single-step over breakpoints without removing them from the debuggee.
4215 Also known as "out-of-line single-stepping".
4218 show debug displaced
4219 Control display of debugging info for displaced stepping.
4221 maint set internal-error
4222 maint show internal-error
4223 Control what GDB does when an internal error is detected.
4225 maint set internal-warning
4226 maint show internal-warning
4227 Control what GDB does when an internal warning is detected.
4232 Use a wrapper program to launch programs for debugging.
4234 set multiple-symbols (all|ask|cancel)
4235 show multiple-symbols
4236 The value of this variable can be changed to adjust the debugger behavior
4237 when an expression or a breakpoint location contains an ambiguous symbol
4238 name (an overloaded function name, for instance).
4240 set breakpoint always-inserted
4241 show breakpoint always-inserted
4242 Keep breakpoints always inserted in the target, as opposed to inserting
4243 them when resuming the target, and removing them when the target stops.
4244 This option can improve debugger performance on slow remote targets.
4246 set arm fallback-mode (arm|thumb|auto)
4247 show arm fallback-mode
4248 set arm force-mode (arm|thumb|auto)
4250 These commands control how ARM GDB determines whether instructions
4251 are ARM or Thumb. The default for both settings is auto, which uses
4252 the current CPSR value for instructions without symbols; previous
4253 versions of GDB behaved as if "set arm fallback-mode arm".
4255 set disable-randomization
4256 show disable-randomization
4257 Standalone programs run with the virtual address space randomization enabled
4258 by default on some platforms. This option keeps the addresses stable across
4259 multiple debugging sessions.
4263 Control whether other threads are stopped or not when some thread hits
4268 Requests that asynchronous execution is enabled in the target, if available.
4269 In this case, it's possible to resume target in the background, and interact
4270 with GDB while the target is running. "show target-async" displays the
4271 current state of asynchronous execution of the target.
4273 set target-wide-charset
4274 show target-wide-charset
4275 The target-wide-charset is the name of the character set that GDB
4276 uses when printing characters whose type is wchar_t.
4278 set tcp auto-retry (on|off)
4280 set tcp connect-timeout
4281 show tcp connect-timeout
4282 These commands allow GDB to retry failed TCP connections to a remote stub
4283 with a specified timeout period; this is useful if the stub is launched
4284 in parallel with GDB but may not be ready to accept connections immediately.
4286 set libthread-db-search-path
4287 show libthread-db-search-path
4288 Control list of directories which GDB will search for appropriate
4291 set schedule-multiple (on|off)
4292 show schedule-multiple
4293 Allow GDB to resume all threads of all processes or only threads of
4294 the current process.
4298 Use more aggressive caching for accesses to the stack. This improves
4299 performance of remote debugging (particularly backtraces) without
4300 affecting correctness.
4302 set interactive-mode (on|off|auto)
4303 show interactive-mode
4304 Control whether GDB runs in interactive mode (on) or not (off).
4305 When in interactive mode, GDB waits for the user to answer all
4306 queries. Otherwise, GDB does not wait and assumes the default
4307 answer. When set to auto (the default), GDB determines which
4308 mode to use based on the stdin settings.
4313 For program forks, this is replaced by the new more generic `info
4314 inferiors' command. To list checkpoints, you can still use the
4315 `info checkpoints' command, which was an alias for the `info forks'
4319 Replaced by the new `inferior' command. To switch between
4320 checkpoints, you can still use the `restart' command, which was an
4321 alias for the `fork' command.
4324 This is removed, since some targets don't have a notion of
4325 processes. To switch between processes, you can still use the
4326 `inferior' command using GDB's own inferior number.
4329 For program forks, this is replaced by the new more generic `kill
4330 inferior' command. To delete a checkpoint, you can still use the
4331 `delete checkpoint' command, which was an alias for the `delete
4335 For program forks, this is replaced by the new more generic `detach
4336 inferior' command. To detach a checkpoint, you can still use the
4337 `detach checkpoint' command, which was an alias for the `detach
4340 * New native configurations
4342 x86/x86_64 Darwin i[34567]86-*-darwin*
4344 x86_64 MinGW x86_64-*-mingw*
4348 Lattice Mico32 lm32-*
4349 x86 DICOS i[34567]86-*-dicos*
4350 x86_64 DICOS x86_64-*-dicos*
4353 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4354 (mingw32ce) debugging.
4360 These commands were actually not implemented on any target.
4362 *** Changes in GDB 6.8
4364 * New native configurations
4366 NetBSD/hppa hppa*-*netbsd*
4367 Xtensa GNU/Linux xtensa*-*-linux*
4371 NetBSD/hppa hppa*-*-netbsd*
4372 Xtensa GNU/Lunux xtensa*-*-linux*
4374 * Change in command line behavior -- corefiles vs. process ids.
4376 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4377 attaching to process NUMBER fails, GDB no longer attempts to open a
4378 core file named NUMBER. Attaching to a program using the -c option
4379 is no longer supported. Instead, use the '-p' or '--pid' options.
4381 * GDB can now be built as a native debugger for debugging Windows x86
4382 (mingw32) Portable Executable (PE) programs.
4384 * Pending breakpoints no longer change their number when their address
4387 * GDB now supports breakpoints with multiple locations,
4388 including breakpoints on C++ constructors, inside C++ templates,
4389 and in inlined functions.
4391 * GDB's ability to debug optimized code has been improved. GDB more
4392 accurately identifies function bodies and lexical blocks that occupy
4393 more than one contiguous range of addresses.
4395 * Target descriptions can now describe registers for PowerPC.
4397 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4398 registers on PowerPC targets.
4400 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4401 targets even when the libthread_db library is not available.
4403 * The GDB remote stub, gdbserver, now supports the new file transfer
4404 commands (remote put, remote get, and remote delete).
4406 * The GDB remote stub, gdbserver, now supports run and attach in
4407 extended-remote mode.
4409 * hppa*64*-*-hpux11* target broken
4410 The debugger is unable to start a program and fails with the following
4411 error: "Error trying to get information about dynamic linker".
4412 The gdb-6.7 release is also affected.
4414 * GDB now supports the --enable-targets= configure option to allow
4415 building a single GDB executable that supports multiple remote
4416 target architectures.
4418 * GDB now supports debugging C and C++ programs which use the
4419 Decimal Floating Point extension. In addition, the PowerPC target
4420 now has a set of pseudo-registers to inspect decimal float values
4421 stored in two consecutive float registers.
4423 * The -break-insert MI command can optionally create pending
4426 * Improved support for debugging Ada
4427 Many improvements to the Ada language support have been made. These
4429 - Better support for Ada2005 interface types
4430 - Improved handling of arrays and slices in general
4431 - Better support for Taft-amendment types
4432 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4434 - Improved command completion in Ada
4437 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4442 set print frame-arguments (all|scalars|none)
4443 show print frame-arguments
4444 The value of this variable can be changed to control which argument
4445 values should be printed by the debugger when displaying a frame.
4450 Transfer files to and from a remote target, and delete remote files.
4457 Transfer files to and from a remote target, and delete remote files.
4459 * New remote packets
4466 Open, close, read, write, and delete files on the remote system.
4469 Attach to an existing process on the remote system, in extended-remote
4473 Run a new process on the remote system, in extended-remote mode.
4475 *** Changes in GDB 6.7
4477 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4478 bfd, libiberty and opcodes, as revealed by static analysis donated by
4479 Coverity, Inc. (http://scan.coverity.com).
4481 * When looking up multiply-defined global symbols, GDB will now prefer the
4482 symbol definition in the current shared library if it was built using the
4483 -Bsymbolic linker option.
4485 * When the Text User Interface (TUI) is not configured, GDB will now
4486 recognize the -tui command-line option and print a message that the TUI
4489 * The GDB remote stub, gdbserver, now has lower overhead for high
4490 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4492 * GDB for MIPS targets now autodetects whether a remote target provides
4493 32-bit or 64-bit register values.
4495 * Support for C++ member pointers has been improved.
4497 * GDB now understands XML target descriptions, which specify the
4498 target's overall architecture. GDB can read a description from
4499 a local file or over the remote serial protocol.
4501 * Vectors of single-byte data use a new integer type which is not
4502 automatically displayed as character or string data.
4504 * The /s format now works with the print command. It displays
4505 arrays of single-byte integers and pointers to single-byte integers
4508 * Target descriptions can now describe target-specific registers,
4509 for architectures which have implemented the support (currently
4510 only ARM, M68K, and MIPS).
4512 * GDB and the GDB remote stub, gdbserver, now support the XScale
4515 * The GDB remote stub, gdbserver, has been updated to support
4516 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4517 has been rewritten to use the standard GDB remote protocol.
4519 * GDB can now step into C++ functions which are called through thunks.
4521 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4523 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4524 layout. It also supports a TextSeg= and DataSeg= response when only
4525 segment base addresses (rather than offsets) are available.
4527 * The /i format now outputs any trailing branch delay slot instructions
4528 immediately following the last instruction within the count specified.
4530 * The GDB remote protocol "T" stop reply packet now supports a
4531 "library" response. Combined with the new "qXfer:libraries:read"
4532 packet, this response allows GDB to debug shared libraries on targets
4533 where the operating system manages the list of loaded libraries (e.g.
4534 Windows and SymbianOS).
4536 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4537 (DLLs) on Windows and Windows CE targets.
4539 * GDB now supports a faster verification that a .debug file matches its binary
4540 according to its build-id signature, if the signature is present.
4546 Enable or disable hardware flow control (RTS/CTS) on the serial port
4547 when debugging using remote targets.
4549 set mem inaccessible-by-default
4550 show mem inaccessible-by-default
4551 If the target supplies a memory map, for instance via the remote
4552 protocol's "qXfer:memory-map:read" packet, setting this variable
4553 prevents GDB from accessing memory outside the memory map. This
4554 is useful for targets with memory mapped registers or which react
4555 badly to accesses of unmapped address space.
4557 set breakpoint auto-hw
4558 show breakpoint auto-hw
4559 If the target supplies a memory map, for instance via the remote
4560 protocol's "qXfer:memory-map:read" packet, setting this variable
4561 lets GDB use hardware breakpoints automatically for memory regions
4562 where it can not use software breakpoints. This covers both the
4563 "break" command and internal breakpoints used for other commands
4564 including "next" and "finish".
4567 catch exception unhandled
4568 Stop the program execution when Ada exceptions are raised.
4571 Stop the program execution when an Ada assertion failed.
4575 Set an alternate system root for target files. This is a more
4576 general version of "set solib-absolute-prefix", which is now
4577 an alias to "set sysroot".
4580 Provide extended SPU facility status information. This set of
4581 commands is available only when debugging the Cell/B.E. SPU
4584 * New native configurations
4586 OpenBSD/sh sh*-*openbsd*
4589 unset tdesc filename
4591 Use the specified local file as an XML target description, and do
4592 not query the target for its built-in description.
4596 OpenBSD/sh sh*-*-openbsd*
4597 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4598 Toshiba Media Processor mep-elf
4600 * New remote packets
4603 Ignore the specified signals; pass them directly to the debugged program
4604 without stopping other threads or reporting them to GDB.
4606 qXfer:features:read:
4607 Read an XML target description from the target, which describes its
4612 Read or write contents of an spufs file on the target system. These
4613 packets are available only on the Cell/B.E. SPU architecture.
4615 qXfer:libraries:read:
4616 Report the loaded shared libraries. Combined with new "T" packet
4617 response, this packet allows GDB to debug shared libraries on
4618 targets where the operating system manages the list of loaded
4619 libraries (e.g. Windows and SymbianOS).
4623 Support for these obsolete configurations has been removed.
4631 i[34567]86-*-lynxos*
4632 i[34567]86-*-netware*
4633 i[34567]86-*-sco3.2v5*
4634 i[34567]86-*-sco3.2v4*
4636 i[34567]86-*-sysv4.2*
4639 i[34567]86-*-unixware2*
4640 i[34567]86-*-unixware*
4649 * Other removed features
4656 Various m68k-only ROM monitors.
4663 Various Renesas ROM monitors and debugging interfaces for SH and
4668 Support for a Macraigor serial interface to on-chip debugging.
4669 GDB does not directly support the newer parallel or USB
4674 A debug information format. The predecessor to DWARF 2 and
4675 DWARF 3, which are still supported.
4677 Support for the HP aCC compiler on HP-UX/PA-RISC
4679 SOM-encapsulated symbolic debugging information, automatic
4680 invocation of pxdb, and the aCC custom C++ ABI. This does not
4681 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4682 with aCC can still be debugged on an assembly level.
4684 MIPS ".pdr" sections
4686 A MIPS-specific format used to describe stack frame layout
4687 in debugging information.
4691 GDB could work with an older version of Guile to debug
4692 the interpreter and Scheme programs running in it.
4694 set mips stack-arg-size
4695 set mips saved-gpreg-size
4697 Use "set mips abi" to control parameter passing for MIPS.
4699 *** Changes in GDB 6.6
4704 Cell Broadband Engine SPU spu-elf
4706 * GDB can now be configured as a cross-debugger targeting native Windows
4707 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4708 running on a Windows system over TCP/IP to debug Windows programs.
4710 * The GDB remote stub, gdbserver, has been updated to support Windows and
4711 Cygwin debugging. Both single-threaded and multi-threaded programs are
4714 * The "set trust-readonly-sections" command works again. This command was
4715 broken in GDB 6.3, 6.4, and 6.5.
4717 * The "load" command now supports writing to flash memory, if the remote
4718 stub provides the required support.
4720 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4721 longer requires symbolic debug information (e.g. DWARF-2).
4726 unset substitute-path
4727 show substitute-path
4728 Manage a list of substitution rules that GDB uses to rewrite the name
4729 of the directories where the sources are located. This can be useful
4730 for instance when the sources were moved to a different location
4731 between compilation and debugging.
4735 Print each CLI command as it is executed. Each command is prefixed with
4736 a number of `+' symbols representing the nesting depth.
4737 The source command now has a `-v' option to enable the same feature.
4741 The ARM Demon monitor support (RDP protocol, "target rdp").
4743 Kernel Object Display, an embedded debugging feature which only worked with
4744 an obsolete version of Cisco IOS.
4746 The 'set download-write-size' and 'show download-write-size' commands.
4748 * New remote packets
4751 Tell a stub about GDB client features, and request remote target features.
4752 The first feature implemented is PacketSize, which allows the target to
4753 specify the size of packets it can handle - to minimize the number of
4754 packets required and improve performance when connected to a remote
4758 Fetch an OS auxilliary vector from the remote stub. This packet is a
4759 more efficient replacement for qPart:auxv:read.
4761 qXfer:memory-map:read:
4762 Fetch a memory map from the remote stub, including information about
4763 RAM, ROM, and flash memory devices.
4768 Erase and program a flash memory device.
4770 * Removed remote packets
4773 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4774 used it, and only gdbserver implemented it.
4776 *** Changes in GDB 6.5
4780 Renesas M32C/M16C m32c-elf
4782 Morpho Technologies ms1 ms1-elf
4786 init-if-undefined Initialize a convenience variable, but
4787 only if it doesn't already have a value.
4789 The following commands are presently only implemented for native GNU/Linux:
4791 checkpoint Save a snapshot of the program state.
4793 restart <n> Return the program state to a
4794 previously saved state.
4796 info checkpoints List currently saved checkpoints.
4798 delete-checkpoint <n> Delete a previously saved checkpoint.
4800 set|show detach-on-fork Tell gdb whether to detach from a newly
4801 forked process, or to keep debugging it.
4803 info forks List forks of the user program that
4804 are available to be debugged.
4806 fork <n> Switch to debugging one of several
4807 forks of the user program that are
4808 available to be debugged.
4810 delete-fork <n> Delete a fork from the list of forks
4811 that are available to be debugged (and
4812 kill the forked process).
4814 detach-fork <n> Delete a fork from the list of forks
4815 that are available to be debugged (and
4816 allow the process to continue).
4820 Morpho Technologies ms2 ms1-elf
4822 * Improved Windows host support
4824 GDB now builds as a cross debugger hosted on i686-mingw32, including
4825 native console support, and remote communications using either
4826 network sockets or serial ports.
4828 * Improved Modula-2 language support
4830 GDB can now print most types in the Modula-2 syntax. This includes:
4831 basic types, set types, record types, enumerated types, range types,
4832 pointer types and ARRAY types. Procedure var parameters are correctly
4833 printed and hexadecimal addresses and character constants are also
4834 written in the Modula-2 syntax. Best results can be obtained by using
4835 GNU Modula-2 together with the -gdwarf-2 command line option.
4839 The ARM rdi-share module.
4841 The Netware NLM debug server.
4843 *** Changes in GDB 6.4
4845 * New native configurations
4847 OpenBSD/arm arm*-*-openbsd*
4848 OpenBSD/mips64 mips64-*-openbsd*
4852 Morpho Technologies ms1 ms1-elf
4854 * New command line options
4856 --batch-silent As for --batch, but totally silent.
4857 --return-child-result The debugger will exist with the same value
4858 the child (debugged) program exited with.
4859 --eval-command COMMAND, -ex COMMAND
4860 Execute a single GDB CLI command. This may be
4861 specified multiple times and in conjunction
4862 with the --command (-x) option.
4864 * Deprecated commands removed
4866 The following commands, that were deprecated in 2000, have been
4870 set|show arm disassembly-flavor set|show arm disassembler
4871 othernames set arm disassembler
4872 set|show remotedebug set|show debug remote
4873 set|show archdebug set|show debug arch
4874 set|show eventdebug set|show debug event
4877 * New BSD user-level threads support
4879 It is now possible to debug programs using the user-level threads
4880 library on OpenBSD and FreeBSD. Currently supported (target)
4883 FreeBSD/amd64 x86_64-*-freebsd*
4884 FreeBSD/i386 i386-*-freebsd*
4885 OpenBSD/i386 i386-*-openbsd*
4887 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4888 are not yet supported.
4890 * New support for Matsushita MN10300 w/sim added
4891 (Work in progress). mn10300-elf.
4893 * REMOVED configurations and files
4895 VxWorks and the XDR protocol *-*-vxworks
4896 Motorola MCORE mcore-*-*
4897 National Semiconductor NS32000 ns32k-*-*
4899 * New "set print array-indexes" command
4901 After turning this setting "on", GDB prints the index of each element
4902 when displaying arrays. The default is "off" to preserve the previous
4905 * VAX floating point support
4907 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4909 * User-defined command support
4911 In addition to using $arg0..$arg9 for argument passing, it is now possible
4912 to use $argc to determine now many arguments have been passed. See the
4913 section on user-defined commands in the user manual for more information.
4915 *** Changes in GDB 6.3:
4917 * New command line option
4919 GDB now accepts -l followed by a number to set the timeout for remote
4922 * GDB works with GCC -feliminate-dwarf2-dups
4924 GDB now supports a more compact representation of DWARF-2 debug
4925 information using DW_FORM_ref_addr references. These are produced
4926 by GCC with the option -feliminate-dwarf2-dups and also by some
4927 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4928 to use -feliminate-dwarf2-dups.
4930 * Internationalization
4932 When supported by the host system, GDB will be built with
4933 internationalization (libintl). The task of marking up the sources is
4934 continued, we're looking forward to our first translation.
4938 Initial support for debugging programs compiled with the GNAT
4939 implementation of the Ada programming language has been integrated
4940 into GDB. In this release, support is limited to expression evaluation.
4942 * New native configurations
4944 GNU/Linux/m32r m32r-*-linux-gnu
4948 GDB's remote protocol now includes support for the 'p' packet. This
4949 packet is used to fetch individual registers from a remote inferior.
4951 * END-OF-LIFE registers[] compatibility module
4953 GDB's internal register infrastructure has been completely rewritten.
4954 The new infrastructure making possible the implementation of key new
4955 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4958 GDB 6.3 will be the last release to include the the registers[]
4959 compatibility module that allowed out-of-date configurations to
4960 continue to work. This change directly impacts the following
4970 powerpc bdm protocol
4972 Unless there is activity to revive these configurations, they will be
4973 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4975 * OBSOLETE configurations and files
4977 Configurations that have been declared obsolete in this release have
4978 been commented out. Unless there is activity to revive these
4979 configurations, the next release of GDB will have their sources
4980 permanently REMOVED.
4989 *** Changes in GDB 6.2.1:
4991 * MIPS `break main; run' gave an heuristic-fence-post warning
4993 When attempting to run even a simple program, a warning about
4994 heuristic-fence-post being hit would be reported. This problem has
4997 * MIPS IRIX 'long double' crashed GDB
4999 When examining a long double variable, GDB would get a segmentation
5000 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5001 IRIX long double values).
5005 A bug in the VAX stack code was causing problems with the "next"
5006 command. This problem has been fixed.
5008 *** Changes in GDB 6.2:
5010 * Fix for ``many threads''
5012 On GNU/Linux systems that use the NPTL threads library, a program
5013 rapidly creating and deleting threads would confuse GDB leading to the
5016 ptrace: No such process.
5017 thread_db_get_info: cannot get thread info: generic error
5019 This problem has been fixed.
5021 * "-async" and "-noasync" options removed.
5023 Support for the broken "-noasync" option has been removed (it caused
5026 * New ``start'' command.
5028 This command runs the program until the begining of the main procedure.
5030 * New BSD Kernel Data Access Library (libkvm) interface
5032 Using ``target kvm'' it is now possible to debug kernel core dumps and
5033 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5034 platforms. Currently supported (native-only) configurations are:
5036 FreeBSD/amd64 x86_64-*-freebsd*
5037 FreeBSD/i386 i?86-*-freebsd*
5038 NetBSD/i386 i?86-*-netbsd*
5039 NetBSD/m68k m68*-*-netbsd*
5040 NetBSD/sparc sparc-*-netbsd*
5041 OpenBSD/amd64 x86_64-*-openbsd*
5042 OpenBSD/i386 i?86-*-openbsd*
5043 OpenBSD/m68k m68*-openbsd*
5044 OpenBSD/sparc sparc-*-openbsd*
5046 * Signal trampoline code overhauled
5048 Many generic problems with GDB's signal handling code have been fixed.
5049 These include: backtraces through non-contiguous stacks; recognition
5050 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5051 call; backtrace through a signal trampoline; step into and out of
5052 signal handlers; and single-stepping in the signal trampoline.
5054 Please note that kernel bugs are a limiting factor here. These
5055 features have been shown to work on an s390 GNU/Linux system that
5056 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5058 * Cygwin support for DWARF 2 added.
5060 * New native configurations
5062 GNU/Linux/hppa hppa*-*-linux*
5063 OpenBSD/hppa hppa*-*-openbsd*
5064 OpenBSD/m68k m68*-*-openbsd*
5065 OpenBSD/m88k m88*-*-openbsd*
5066 OpenBSD/powerpc powerpc-*-openbsd*
5067 NetBSD/vax vax-*-netbsd*
5068 OpenBSD/vax vax-*-openbsd*
5070 * END-OF-LIFE frame compatibility module
5072 GDB's internal frame infrastructure has been completely rewritten.
5073 The new infrastructure making it possible to support key new features
5074 including DWARF 2 Call Frame Information. To aid in the task of
5075 migrating old configurations to this new infrastructure, a
5076 compatibility module, that allowed old configurations to continue to
5077 work, was also included.
5079 GDB 6.2 will be the last release to include this frame compatibility
5080 module. This change directly impacts the following configurations:
5090 Unless there is activity to revive these configurations, they will be
5091 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5093 * REMOVED configurations and files
5095 Sun 3, running SunOS 3 m68*-*-sunos3*
5096 Sun 3, running SunOS 4 m68*-*-sunos4*
5097 Sun 2, running SunOS 3 m68000-*-sunos3*
5098 Sun 2, running SunOS 4 m68000-*-sunos4*
5099 Motorola 680x0 running LynxOS m68*-*-lynxos*
5100 AT&T 3b1/Unix pc m68*-att-*
5101 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5102 decstation mips-dec-* mips-little-*
5103 riscos mips-*-riscos* mips-*-sysv*
5104 sonymips mips-sony-*
5105 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5107 *** Changes in GDB 6.1.1:
5109 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5111 The TUI (Text-mode User Interface) is now built as part of a default
5112 GDB configuration. It is enabled by either selecting the TUI with the
5113 command line option "-i=tui" or by running the separate "gdbtui"
5114 program. For more information on the TUI, see the manual "Debugging
5117 * Pending breakpoint support (also included in GDB 6.1)
5119 Support has been added to allow you to specify breakpoints in shared
5120 libraries that have not yet been loaded. If a breakpoint location
5121 cannot be found, and the "breakpoint pending" option is set to auto,
5122 GDB queries you if you wish to make the breakpoint pending on a future
5123 shared-library load. If and when GDB resolves the breakpoint symbol,
5124 the pending breakpoint is removed as one or more regular breakpoints
5127 Pending breakpoints are very useful for GCJ Java debugging.
5129 * Fixed ISO-C build problems
5131 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5132 non ISO-C code that stopped them being built using a more strict ISO-C
5133 compiler (e.g., IBM's C compiler).
5135 * Fixed build problem on IRIX 5
5137 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5138 wasn't able to compile compile on an IRIX 5 system.
5140 * Added execute permission to gdb/gdbserver/configure
5142 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5143 permission. This bug would cause configure to fail on a number of
5144 systems (Solaris, IRIX). Ref: server/519.
5146 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5148 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5149 has been updated to use constant array sizes.
5151 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5153 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5154 its generated DWARF Call Frame Info. This encoding was causing GDB to
5155 panic, that panic has been fixed. Ref: gdb/1628.
5157 * Fixed a problem when examining parameters in shared library code.
5159 When examining parameters in optimized shared library code generated
5160 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5161 not available''. GDB now correctly displays the variable's value.
5163 *** Changes in GDB 6.1:
5165 * Removed --with-mmalloc
5167 Support for the mmalloc memory manager has been removed, as it
5168 conflicted with the internal gdb byte cache.
5170 * Changes in AMD64 configurations
5172 The AMD64 target now includes the %cs and %ss registers. As a result
5173 the AMD64 remote protocol has changed; this affects the floating-point
5174 and SSE registers. If you rely on those registers for your debugging,
5175 you should upgrade gdbserver on the remote side.
5177 * Revised SPARC target
5179 The SPARC target has been completely revised, incorporating the
5180 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5181 support for LynxOS and SunOS 4 has been dropped. Calling functions
5182 from within GDB on operating systems with a non-executable stack
5183 (Solaris, OpenBSD) now works.
5187 GDB has a new C++ demangler which does a better job on the mangled
5188 names generated by current versions of g++. It also runs faster, so
5189 with this and other changes gdb should now start faster on large C++
5192 * DWARF 2 Location Expressions
5194 GDB support for location expressions has been extended to support function
5195 arguments and frame bases. Older versions of GDB could crash when they
5198 * C++ nested types and namespaces
5200 GDB's support for nested types and namespaces in C++ has been
5201 improved, especially if you use the DWARF 2 debugging format. (This
5202 is the default for recent versions of GCC on most platforms.)
5203 Specifically, if you have a class "Inner" defined within a class or
5204 namespace "Outer", then GDB realizes that the class's name is
5205 "Outer::Inner", not simply "Inner". This should greatly reduce the
5206 frequency of complaints about not finding RTTI symbols. In addition,
5207 if you are stopped at inside of a function defined within a namespace,
5208 GDB modifies its name lookup accordingly.
5210 * New native configurations
5212 NetBSD/amd64 x86_64-*-netbsd*
5213 OpenBSD/amd64 x86_64-*-openbsd*
5214 OpenBSD/alpha alpha*-*-openbsd*
5215 OpenBSD/sparc sparc-*-openbsd*
5216 OpenBSD/sparc64 sparc64-*-openbsd*
5218 * New debugging protocols
5220 M32R with SDI protocol m32r-*-elf*
5222 * "set prompt-escape-char" command deleted.
5224 The command "set prompt-escape-char" has been deleted. This command,
5225 and its very obscure effet on GDB's prompt, was never documented,
5226 tested, nor mentioned in the NEWS file.
5228 * OBSOLETE configurations and files
5230 Configurations that have been declared obsolete in this release have
5231 been commented out. Unless there is activity to revive these
5232 configurations, the next release of GDB will have their sources
5233 permanently REMOVED.
5235 Sun 3, running SunOS 3 m68*-*-sunos3*
5236 Sun 3, running SunOS 4 m68*-*-sunos4*
5237 Sun 2, running SunOS 3 m68000-*-sunos3*
5238 Sun 2, running SunOS 4 m68000-*-sunos4*
5239 Motorola 680x0 running LynxOS m68*-*-lynxos*
5240 AT&T 3b1/Unix pc m68*-att-*
5241 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5242 decstation mips-dec-* mips-little-*
5243 riscos mips-*-riscos* mips-*-sysv*
5244 sonymips mips-sony-*
5245 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5247 * REMOVED configurations and files
5249 SGI Irix-4.x mips-sgi-irix4 or iris4
5250 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5251 Z8000 simulator z8k-zilog-none or z8ksim
5252 Matsushita MN10200 w/simulator mn10200-*-*
5253 H8/500 simulator h8500-hitachi-hms or h8500hms
5254 HP/PA running BSD hppa*-*-bsd*
5255 HP/PA running OSF/1 hppa*-*-osf*
5256 HP/PA Pro target hppa*-*-pro*
5257 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5258 386BSD i[3456]86-*-bsd*
5259 Sequent family i[3456]86-sequent-sysv4*
5260 i[3456]86-sequent-sysv*
5261 i[3456]86-sequent-bsd*
5262 SPARC running LynxOS sparc-*-lynxos*
5263 SPARC running SunOS 4 sparc-*-sunos4*
5264 Tsqware Sparclet sparclet-*-*
5265 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5267 *** Changes in GDB 6.0:
5271 Support for debugging the Objective-C programming language has been
5272 integrated into GDB.
5274 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5276 DWARF 2's Call Frame Information makes available compiler generated
5277 information that more exactly describes the program's run-time stack.
5278 By using this information, GDB is able to provide more robust stack
5281 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5282 have been updated to use a new backtrace mechanism which includes
5283 DWARF 2 CFI support.
5287 GDB's remote protocol has been extended to include support for hosted
5288 file I/O (where the remote target uses GDB's file system). See GDB's
5289 remote protocol documentation for details.
5291 * All targets using the new architecture framework.
5293 All of GDB's targets have been updated to use the new internal
5294 architecture framework. The way is now open for future GDB releases
5295 to include cross-architecture native debugging support (i386 on amd64,
5298 * GNU/Linux's Thread Local Storage (TLS)
5300 GDB now includes support for for the GNU/Linux implementation of
5301 per-thread variables.
5303 * GNU/Linux's Native POSIX Thread Library (NPTL)
5305 GDB's thread code has been updated to work with either the new
5306 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5308 * Separate debug info.
5310 GDB, in conjunction with BINUTILS, now supports a mechanism for
5311 automatically loading debug information from a separate file. Instead
5312 of shipping full debug and non-debug versions of system libraries,
5313 system integrators can now instead ship just the stripped libraries
5314 and optional debug files.
5316 * DWARF 2 Location Expressions
5318 DWARF 2 Location Expressions allow the compiler to more completely
5319 describe the location of variables (even in optimized code) to the
5322 GDB now includes preliminary support for location expressions (support
5323 for DW_OP_piece is still missing).
5327 A number of long standing bugs that caused GDB to die while starting a
5328 Java application have been fixed. GDB's Java support is now
5329 considered "useable".
5331 * GNU/Linux support for fork, vfork, and exec.
5333 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5334 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5337 * GDB supports logging output to a file
5339 There are two new commands, "set logging" and "show logging", which can be
5340 used to capture GDB's output to a file.
5342 * The meaning of "detach" has changed for gdbserver
5344 The "detach" command will now resume the application, as documented. To
5345 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5348 * d10v, m68hc11 `regs' command deprecated
5350 The `info registers' command has been updated so that it displays the
5351 registers using a format identical to the old `regs' command.
5355 A new command, "maint set profile on/off", has been added. This command can
5356 be used to enable or disable profiling while running GDB, to profile a
5357 session or a set of commands. In addition there is a new configure switch,
5358 "--enable-profiling", which will cause GDB to be compiled with profiling
5359 data, for more informative profiling results.
5361 * Default MI syntax changed to "mi2".
5363 The default MI (machine interface) syntax, enabled by the command line
5364 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5365 "mi1", can be enabled by specifying the option "-i=mi1".
5367 Support for the original "mi0" syntax (included in GDB 5.0) has been
5370 Fix for gdb/192: removed extraneous space when displaying frame level.
5371 Fix for gdb/672: update changelist is now output in mi list format.
5372 Fix for gdb/702: a -var-assign that updates the value now shows up
5373 in a subsequent -var-update.
5375 * New native configurations.
5377 FreeBSD/amd64 x86_64-*-freebsd*
5379 * Multi-arched targets.
5381 HP/PA HPUX11 hppa*-*-hpux*
5382 Renesas M32R/D w/simulator m32r-*-elf*
5384 * OBSOLETE configurations and files
5386 Configurations that have been declared obsolete in this release have
5387 been commented out. Unless there is activity to revive these
5388 configurations, the next release of GDB will have their sources
5389 permanently REMOVED.
5391 Z8000 simulator z8k-zilog-none or z8ksim
5392 Matsushita MN10200 w/simulator mn10200-*-*
5393 H8/500 simulator h8500-hitachi-hms or h8500hms
5394 HP/PA running BSD hppa*-*-bsd*
5395 HP/PA running OSF/1 hppa*-*-osf*
5396 HP/PA Pro target hppa*-*-pro*
5397 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5398 Sequent family i[3456]86-sequent-sysv4*
5399 i[3456]86-sequent-sysv*
5400 i[3456]86-sequent-bsd*
5401 Tsqware Sparclet sparclet-*-*
5402 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5404 * REMOVED configurations and files
5407 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5408 IBM AIX PS/2 i[3456]86-*-aix
5409 i386 running Mach 3.0 i[3456]86-*-mach3*
5410 i386 running Mach i[3456]86-*-mach*
5411 i386 running OSF/1 i[3456]86-*osf1mk*
5412 HP/Apollo 68k Family m68*-apollo*-sysv*,
5414 m68*-hp-bsd*, m68*-hp-hpux*
5415 Argonaut Risc Chip (ARC) arc-*-*
5416 Mitsubishi D30V d30v-*-*
5417 Fujitsu FR30 fr30-*-elf*
5418 OS/9000 i[34]86-*-os9k
5419 I960 with MON960 i960-*-coff
5421 * MIPS $fp behavior changed
5423 The convenience variable $fp, for the MIPS, now consistently returns
5424 the address of the current frame's base. Previously, depending on the
5425 context, $fp could refer to either $sp or the current frame's base
5426 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5427 The GNU Source-Level Debugger''.
5429 *** Changes in GDB 5.3:
5431 * GNU/Linux shared library multi-threaded performance improved.
5433 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5434 `/proc', in preference to `ptrace' for memory reads. This may result
5435 in an improvement in the start-up time of multi-threaded, shared
5436 library applications when run under GDB. One GDB user writes: ``loads
5437 shared libs like mad''.
5439 * ``gdbserver'' now supports multi-threaded applications on some targets
5441 Support for debugging multi-threaded applications which use
5442 the GNU/Linux LinuxThreads package has been added for
5443 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5444 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5446 * GDB now supports C/C++ preprocessor macros.
5448 GDB now expands preprocessor macro invocations in C/C++ expressions,
5449 and provides various commands for showing macro definitions and how
5452 The new command `macro expand EXPRESSION' expands any macro
5453 invocations in expression, and shows the result.
5455 The new command `show macro MACRO-NAME' shows the definition of the
5456 macro named MACRO-NAME, and where it was defined.
5458 Most compilers don't include information about macros in the debugging
5459 information by default. In GCC 3.1, for example, you need to compile
5460 your program with the options `-gdwarf-2 -g3'. If the macro
5461 information is present in the executable, GDB will read it.
5463 * Multi-arched targets.
5465 DEC Alpha (partial) alpha*-*-*
5466 DEC VAX (partial) vax-*-*
5468 National Semiconductor NS32000 (partial) ns32k-*-*
5469 Motorola 68000 (partial) m68k-*-*
5470 Motorola MCORE mcore-*-*
5474 Fujitsu FRV architecture added by Red Hat frv*-*-*
5477 * New native configurations
5479 Alpha NetBSD alpha*-*-netbsd*
5480 SH NetBSD sh*-*-netbsdelf*
5481 MIPS NetBSD mips*-*-netbsd*
5482 UltraSPARC NetBSD sparc64-*-netbsd*
5484 * OBSOLETE configurations and files
5486 Configurations that have been declared obsolete in this release have
5487 been commented out. Unless there is activity to revive these
5488 configurations, the next release of GDB will have their sources
5489 permanently REMOVED.
5491 Mitsubishi D30V d30v-*-*
5492 OS/9000 i[34]86-*-os9k
5493 IBM AIX PS/2 i[3456]86-*-aix
5494 Fujitsu FR30 fr30-*-elf*
5495 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5496 Argonaut Risc Chip (ARC) arc-*-*
5497 i386 running Mach 3.0 i[3456]86-*-mach3*
5498 i386 running Mach i[3456]86-*-mach*
5499 i386 running OSF/1 i[3456]86-*osf1mk*
5500 HP/Apollo 68k Family m68*-apollo*-sysv*,
5502 m68*-hp-bsd*, m68*-hp-hpux*
5503 I960 with MON960 i960-*-coff
5505 * OBSOLETE languages
5507 CHILL, a Pascal like language used by telecommunications companies.
5509 * REMOVED configurations and files
5511 AMD 29k family via UDI a29k-amd-udi, udi29k
5512 A29K VxWorks a29k-*-vxworks
5513 AMD 29000 embedded, using EBMON a29k-none-none
5514 AMD 29000 embedded with COFF a29k-none-coff
5515 AMD 29000 embedded with a.out a29k-none-aout
5517 testsuite/gdb.hp/gdb.threads-hp/ directory
5519 * New command "set max-user-call-depth <nnn>"
5521 This command allows the user to limit the call depth of user-defined
5522 commands. The default is 1024.
5524 * Changes in FreeBSD/i386 native debugging.
5526 Support for the "generate-core-file" has been added.
5528 * New commands "dump", "append", and "restore".
5530 These commands allow data to be copied from target memory
5531 to a bfd-format or binary file (dump and append), and back
5532 from a file into memory (restore).
5534 * Improved "next/step" support on multi-processor Alpha Tru64.
5536 The previous single-step mechanism could cause unpredictable problems,
5537 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5538 of a software single-step mechanism prevents this.
5540 *** Changes in GDB 5.2.1:
5548 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5549 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5550 Fix, by Joel Brobecker imported from mainline.
5552 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5553 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5554 Fix, by Fred Fish, imported from mainline.
5556 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5557 Surprisingly enough, it works now.
5558 By Michal Ludvig, imported from mainline.
5560 i386 hardware watchpoint support:
5561 avoid misses on second run for some targets.
5562 By Pierre Muller, imported from mainline.
5564 *** Changes in GDB 5.2:
5566 * New command "set trust-readonly-sections on[off]".
5568 This command is a hint that tells gdb that read-only sections
5569 really are read-only (ie. that their contents will not change).
5570 In this mode, gdb will go to the object file rather than the
5571 target to read memory from read-only sections (such as ".text").
5572 This can be a significant performance improvement on some
5573 (notably embedded) targets.
5575 * New command "generate-core-file" (or "gcore").
5577 This new gdb command allows the user to drop a core file of the child
5578 process state at any time. So far it's been implemented only for
5579 GNU/Linux and Solaris, but should be relatively easily ported to other
5580 hosts. Argument is core file name (defaults to core.<pid>).
5582 * New command line option
5584 GDB now accepts --pid or -p followed by a process id.
5586 * Change in command line behavior -- corefiles vs. process ids.
5588 There is a subtle behavior in the way in which GDB handles
5589 command line arguments. The first non-flag argument is always
5590 a program to debug, but the second non-flag argument may either
5591 be a corefile or a process id. Previously, GDB would attempt to
5592 open the second argument as a corefile, and if that failed, would
5593 issue a superfluous error message and then attempt to attach it as
5594 a process. Now, if the second argument begins with a non-digit,
5595 it will be treated as a corefile. If it begins with a digit,
5596 GDB will attempt to attach it as a process, and if no such process
5597 is found, will then attempt to open it as a corefile.
5599 * Changes in ARM configurations.
5601 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5602 configuration is fully multi-arch.
5604 * New native configurations
5606 ARM NetBSD arm*-*-netbsd*
5607 x86 OpenBSD i[3456]86-*-openbsd*
5608 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5609 Sparc64 running FreeBSD sparc64-*-freebsd*
5613 Sanyo XStormy16 xstormy16-elf
5615 * OBSOLETE configurations and files
5617 Configurations that have been declared obsolete in this release have
5618 been commented out. Unless there is activity to revive these
5619 configurations, the next release of GDB will have their sources
5620 permanently REMOVED.
5622 AMD 29k family via UDI a29k-amd-udi, udi29k
5623 A29K VxWorks a29k-*-vxworks
5624 AMD 29000 embedded, using EBMON a29k-none-none
5625 AMD 29000 embedded with COFF a29k-none-coff
5626 AMD 29000 embedded with a.out a29k-none-aout
5628 testsuite/gdb.hp/gdb.threads-hp/ directory
5630 * REMOVED configurations and files
5632 TI TMS320C80 tic80-*-*
5634 PowerPC Solaris powerpcle-*-solaris*
5635 PowerPC Windows NT powerpcle-*-cygwin32
5636 PowerPC Netware powerpc-*-netware*
5637 Harris/CXUX m88k m88*-harris-cxux*
5638 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5639 ns32k-utek-sysv* ns32k-utek-*
5640 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5641 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5642 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5643 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5644 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5646 * Changes to command line processing
5648 The new `--args' feature can be used to specify command-line arguments
5649 for the inferior from gdb's command line.
5651 * Changes to key bindings
5653 There is a new `operate-and-get-next' function bound to `C-o'.
5655 *** Changes in GDB 5.1.1
5657 Fix compile problem on DJGPP.
5659 Fix a problem with floating-point registers on the i386 being
5662 Fix to stop GDB crashing on .debug_str debug info.
5664 Numerous documentation fixes.
5666 Numerous testsuite fixes.
5668 *** Changes in GDB 5.1:
5670 * New native configurations
5672 Alpha FreeBSD alpha*-*-freebsd*
5673 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5674 MIPS GNU/Linux mips*-*-linux*
5675 MIPS SGI Irix 6.x mips*-sgi-irix6*
5676 ia64 AIX ia64-*-aix*
5677 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5681 Motorola 68HC11 and 68HC12 m68hc11-elf
5683 UltraSparc running GNU/Linux sparc64-*-linux*
5685 * OBSOLETE configurations and files
5687 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5688 Harris/CXUX m88k m88*-harris-cxux*
5689 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5690 ns32k-utek-sysv* ns32k-utek-*
5691 TI TMS320C80 tic80-*-*
5693 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5694 PowerPC Solaris powerpcle-*-solaris*
5695 PowerPC Windows NT powerpcle-*-cygwin32
5696 PowerPC Netware powerpc-*-netware*
5697 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5698 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5699 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5700 Apple Macintosh (MPW) host N/A
5702 stuff.c (Program to stuff files into a specially prepared space in kdb)
5703 kdb-start.c (Main loop for the standalone kernel debugger)
5705 Configurations that have been declared obsolete in this release have
5706 been commented out. Unless there is activity to revive these
5707 configurations, the next release of GDB will have their sources
5708 permanently REMOVED.
5710 * REMOVED configurations and files
5712 Altos 3068 m68*-altos-*
5713 Convex c1-*-*, c2-*-*
5715 ARM RISCix arm-*-* (as host)
5719 * GDB has been converted to ISO C.
5721 GDB's source code has been converted to ISO C. In particular, the
5722 sources are fully protoized, and rely on standard headers being
5727 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5729 * The MI enabled by default.
5731 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5732 revised and enabled by default. Packages which use GDB as a debugging
5733 engine behind a UI or another front end are encouraged to switch to
5734 using the GDB/MI interface, instead of the old annotations interface
5735 which is now deprecated.
5737 * Support for debugging Pascal programs.
5739 GDB now includes support for debugging Pascal programs. The following
5740 main features are supported:
5742 - Pascal-specific data types such as sets;
5744 - automatic recognition of Pascal sources based on file-name
5747 - Pascal-style display of data types, variables, and functions;
5749 - a Pascal expression parser.
5751 However, some important features are not yet supported.
5753 - Pascal string operations are not supported at all;
5755 - there are some problems with boolean types;
5757 - Pascal type hexadecimal constants are not supported
5758 because they conflict with the internal variables format;
5760 - support for Pascal objects and classes is not full yet;
5762 - unlike Pascal, GDB is case-sensitive for symbol names.
5764 * Changes in completion.
5766 Commands such as `shell', `run' and `set args', which pass arguments
5767 to inferior programs, now complete on file names, similar to what
5768 users expect at the shell prompt.
5770 Commands which accept locations, such as `disassemble', `print',
5771 `breakpoint', `until', etc. now complete on filenames as well as
5772 program symbols. Thus, if you type "break foob TAB", and the source
5773 files linked into the programs include `foobar.c', that file name will
5774 be one of the candidates for completion. However, file names are not
5775 considered for completion after you typed a colon that delimits a file
5776 name from a name of a function in that file, as in "break foo.c:bar".
5778 `set demangle-style' completes on available demangling styles.
5780 * New platform-independent commands:
5782 It is now possible to define a post-hook for a command as well as a
5783 hook that runs before the command. For more details, see the
5784 documentation of `hookpost' in the GDB manual.
5786 * Changes in GNU/Linux native debugging.
5788 Support for debugging multi-threaded programs has been completely
5789 revised for all platforms except m68k and sparc. You can now debug as
5790 many threads as your system allows you to have.
5792 Attach/detach is supported for multi-threaded programs.
5794 Support for SSE registers was added for x86. This doesn't work for
5795 multi-threaded programs though.
5797 * Changes in MIPS configurations.
5799 Multi-arch support is enabled for all MIPS configurations.
5801 GDB can now be built as native debugger on SGI Irix 6.x systems for
5802 debugging n32 executables. (Debugging 64-bit executables is not yet
5805 * Unified support for hardware watchpoints in all x86 configurations.
5807 Most (if not all) native x86 configurations support hardware-assisted
5808 breakpoints and watchpoints in a unified manner. This support
5809 implements debug register sharing between watchpoints, which allows to
5810 put a virtually infinite number of watchpoints on the same address,
5811 and also supports watching regions up to 16 bytes with several debug
5814 The new maintenance command `maintenance show-debug-regs' toggles
5815 debugging print-outs in functions that insert, remove, and test
5816 watchpoints and hardware breakpoints.
5818 * Changes in the DJGPP native configuration.
5820 New command ``info dos sysinfo'' displays assorted information about
5821 the CPU, OS, memory, and DPMI server.
5823 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5824 display information about segment descriptors stored in GDT, LDT, and
5827 New commands ``info dos pde'' and ``info dos pte'' display entries
5828 from Page Directory and Page Tables (for now works with CWSDPMI only).
5829 New command ``info dos address-pte'' displays the Page Table entry for
5830 a given linear address.
5832 GDB can now pass command lines longer than 126 characters to the
5833 program being debugged (requires an update to the libdbg.a library
5834 which is part of the DJGPP development kit).
5836 DWARF2 debug info is now supported.
5838 It is now possible to `step' and `next' through calls to `longjmp'.
5840 * Changes in documentation.
5842 All GDB documentation was converted to GFDL, the GNU Free
5843 Documentation License.
5845 Tracepoints-related commands are now fully documented in the GDB
5848 TUI, the Text-mode User Interface, is now documented in the manual.
5850 Tracepoints-related commands are now fully documented in the GDB
5853 The "GDB Internals" manual now has an index. It also includes
5854 documentation of `ui_out' functions, GDB coding standards, x86
5855 hardware watchpoints, and memory region attributes.
5857 * GDB's version number moved to ``version.in''
5859 The Makefile variable VERSION has been replaced by the file
5860 ``version.in''. People creating GDB distributions should update the
5861 contents of this file.
5865 GUD support is now a standard part of the EMACS distribution.
5867 *** Changes in GDB 5.0:
5869 * Improved support for debugging FP programs on x86 targets
5871 Unified and much-improved support for debugging floating-point
5872 programs on all x86 targets. In particular, ``info float'' now
5873 displays the FP registers in the same format on all x86 targets, with
5874 greater level of detail.
5876 * Improvements and bugfixes in hardware-assisted watchpoints
5878 It is now possible to watch array elements, struct members, and
5879 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5880 on x86 targets no longer erroneously trigger when the address is
5883 * Improvements in the native DJGPP version of GDB
5885 The distribution now includes all the scripts and auxiliary files
5886 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5887 machines ``out of the box''.
5889 The DJGPP version can now debug programs that use signals. It is
5890 possible to catch signals that happened in the debuggee, deliver
5891 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5892 would kill the program being debugged.) Programs that hook hardware
5893 interrupts (keyboard, timer, etc.) can also be debugged.
5895 It is now possible to debug DJGPP programs that redirect their
5896 standard handles or switch them to raw (as opposed to cooked) mode, or
5897 even close them. The command ``run < foo > bar'' works as expected,
5898 and ``info terminal'' reports useful information about the debuggee's
5899 terminal, including raw/cooked mode, redirection, etc.
5901 The DJGPP version now uses termios functions for console I/O, which
5902 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5905 DOS-style file names with drive letters are now fully supported by
5908 It is now possible to debug DJGPP programs that switch their working
5909 directory. It is also possible to rerun the debuggee any number of
5910 times without restarting GDB; thus, you can use the same setup,
5911 breakpoints, etc. for many debugging sessions.
5913 * New native configurations
5915 ARM GNU/Linux arm*-*-linux*
5916 PowerPC GNU/Linux powerpc-*-linux*
5920 Motorola MCore mcore-*-*
5921 x86 VxWorks i[3456]86-*-vxworks*
5922 PowerPC VxWorks powerpc-*-vxworks*
5923 TI TMS320C80 tic80-*-*
5925 * OBSOLETE configurations
5927 Altos 3068 m68*-altos-*
5928 Convex c1-*-*, c2-*-*
5930 ARM RISCix arm-*-* (as host)
5933 Configurations that have been declared obsolete will be commented out,
5934 but the code will be left in place. If there is no activity to revive
5935 these configurations before the next release of GDB, the sources will
5936 be permanently REMOVED.
5938 * Gould support removed
5940 Support for the Gould PowerNode and NP1 has been removed.
5942 * New features for SVR4
5944 On SVR4 native platforms (such as Solaris), if you attach to a process
5945 without first loading a symbol file, GDB will now attempt to locate and
5946 load symbols from the running process's executable file.
5948 * Many C++ enhancements
5950 C++ support has been greatly improved. Overload resolution now works properly
5951 in almost all cases. RTTI support is on the way.
5953 * Remote targets can connect to a sub-program
5955 A popen(3) style serial-device has been added. This device starts a
5956 sub-process (such as a stand-alone simulator) and then communicates
5957 with that. The sub-program to run is specified using the syntax
5958 ``|<program> <args>'' vis:
5960 (gdb) set remotedebug 1
5961 (gdb) target extended-remote |mn10300-elf-sim program-args
5963 * MIPS 64 remote protocol
5965 A long standing bug in the mips64 remote protocol where by GDB
5966 expected certain 32 bit registers (ex SR) to be transfered as 32
5967 instead of 64 bits has been fixed.
5969 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5970 added to provide backward compatibility with older versions of GDB.
5972 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5974 The command ``set remotebinarydownload'' command has been replaced by
5975 ``set remote X-packet''. Other commands in ``set remote'' family
5976 include ``set remote P-packet''.
5978 * Breakpoint commands accept ranges.
5980 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5981 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5982 ``tracepoint passcount'' also accepts a range of tracepoints.
5984 * ``apropos'' command added.
5986 The ``apropos'' command searches through command names and
5987 documentation strings, printing out matches, making it much easier to
5988 try to find a command that does what you are looking for.
5992 A new machine oriented interface (MI) has been added to GDB. This
5993 interface is designed for debug environments running GDB as a separate
5994 process. This is part of the long term libGDB project. See the
5995 "GDB/MI" chapter of the GDB manual for further information. It can be
5996 enabled by configuring with:
5998 .../configure --enable-gdbmi
6000 *** Changes in GDB-4.18:
6002 * New native configurations
6004 HP-UX 10.20 hppa*-*-hpux10.20
6005 HP-UX 11.x hppa*-*-hpux11.0*
6006 M68K GNU/Linux m68*-*-linux*
6010 Fujitsu FR30 fr30-*-elf*
6011 Intel StrongARM strongarm-*-*
6012 Mitsubishi D30V d30v-*-*
6014 * OBSOLETE configurations
6016 Gould PowerNode, NP1 np1-*-*, pn-*-*
6018 Configurations that have been declared obsolete will be commented out,
6019 but the code will be left in place. If there is no activity to revive
6020 these configurations before the next release of GDB, the sources will
6021 be permanently REMOVED.
6025 As a compatibility experiment, GDB's source files buildsym.h and
6026 buildsym.c have been converted to pure standard C, no longer
6027 containing any K&R compatibility code. We believe that all systems in
6028 use today either come with a standard C compiler, or have a GCC port
6029 available. If this is not true, please report the affected
6030 configuration to bug-gdb@gnu.org immediately. See the README file for
6031 information about getting a standard C compiler if you don't have one
6036 GDB now uses readline 2.2.
6038 * set extension-language
6040 You can now control the mapping between filename extensions and source
6041 languages by using the `set extension-language' command. For instance,
6042 you can ask GDB to treat .c files as C++ by saying
6043 set extension-language .c c++
6044 The command `info extensions' lists all of the recognized extensions
6045 and their associated languages.
6047 * Setting processor type for PowerPC and RS/6000
6049 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6050 you can use the `set processor' command to specify what variant of the
6051 PowerPC family you are debugging. The command
6055 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6056 following PowerPC and RS6000 variants:
6058 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6059 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6061 403GC IBM PowerPC 403GC
6062 505 Motorola PowerPC 505
6063 860 Motorola PowerPC 860 or 850
6064 601 Motorola PowerPC 601
6065 602 Motorola PowerPC 602
6066 603 Motorola/IBM PowerPC 603 or 603e
6067 604 Motorola PowerPC 604 or 604e
6068 750 Motorola/IBM PowerPC 750 or 750
6070 At the moment, this command just tells GDB what to name the
6071 special-purpose processor registers. Since almost all the affected
6072 registers are inaccessible to user-level programs, this command is
6073 only useful for remote debugging in its present form.
6077 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6078 more extensive support for HP-UX. Added features include shared
6079 library support, kernel threads and hardware watchpoints for 11.00,
6080 support for HP's ANSI C and C++ compilers, and a compatibility mode
6081 for xdb and dbx commands.
6085 HP's donation includes the new concept of catchpoints, which is a
6086 generalization of the old catch command. On HP-UX, it is now possible
6087 to catch exec, fork, and vfork, as well as library loading.
6089 This means that the existing catch command has changed; its first
6090 argument now specifies the type of catch to be set up. See the
6091 output of "help catch" for a list of catchpoint types.
6093 * Debugging across forks
6095 On HP-UX, you can choose which process to debug when a fork() happens
6100 HP has donated a curses-based terminal user interface (TUI). To get
6101 it, build with --enable-tui. Although this can be enabled for any
6102 configuration, at present it only works for native HP debugging.
6104 * GDB remote protocol additions
6106 A new protocol packet 'X' that writes binary data is now available.
6107 Default behavior is to try 'X', then drop back to 'M' if the stub
6108 fails to respond. The settable variable `remotebinarydownload'
6109 allows explicit control over the use of 'X'.
6111 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6112 full 64-bit address. The command
6114 set remoteaddresssize 32
6116 can be used to revert to the old behaviour. For existing remote stubs
6117 the change should not be noticed, as the additional address information
6120 In order to assist in debugging stubs, you may use the maintenance
6121 command `packet' to send any text string to the stub. For instance,
6123 maint packet heythere
6125 sends the packet "$heythere#<checksum>". Note that it is very easy to
6126 disrupt a debugging session by sending the wrong packet at the wrong
6129 The compare-sections command allows you to compare section data on the
6130 target to what is in the executable file without uploading or
6131 downloading, by comparing CRC checksums.
6133 * Tracing can collect general expressions
6135 You may now collect general expressions at tracepoints. This requires
6136 further additions to the target-side stub; see tracepoint.c and
6137 doc/agentexpr.texi for further details.
6139 * mask-address variable for Mips
6141 For Mips targets, you may control the zeroing of the upper 32 bits of
6142 a 64-bit address by entering `set mask-address on'. This is mainly
6143 of interest to users of embedded R4xxx and R5xxx processors.
6145 * Higher serial baud rates
6147 GDB's serial code now allows you to specify baud rates 57600, 115200,
6148 230400, and 460800 baud. (Note that your host system may not be able
6149 to achieve all of these rates.)
6153 The i960 configuration now includes an initial implementation of a
6154 builtin simulator, contributed by Jim Wilson.
6157 *** Changes in GDB-4.17:
6159 * New native configurations
6161 Alpha GNU/Linux alpha*-*-linux*
6162 Unixware 2.x i[3456]86-unixware2*
6163 Irix 6.x mips*-sgi-irix6*
6164 PowerPC GNU/Linux powerpc-*-linux*
6165 PowerPC Solaris powerpcle-*-solaris*
6166 Sparc GNU/Linux sparc-*-linux*
6167 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6171 Argonaut Risc Chip (ARC) arc-*-*
6172 Hitachi H8/300S h8300*-*-*
6173 Matsushita MN10200 w/simulator mn10200-*-*
6174 Matsushita MN10300 w/simulator mn10300-*-*
6175 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6176 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6177 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6178 Mitsubishi D10V w/simulator d10v-*-*
6179 Mitsubishi M32R/D w/simulator m32r-*-elf*
6180 Tsqware Sparclet sparclet-*-*
6181 NEC V850 w/simulator v850-*-*
6183 * New debugging protocols
6185 ARM with RDI protocol arm*-*-*
6186 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6187 DDB and LSI variants of PMON protocol mips*-*-*
6188 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6189 PowerPC with SDS protocol powerpc{,le}-*-eabi
6190 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6194 All configurations can now understand and use the DWARF 2 debugging
6195 format. The choice is automatic, if the symbol file contains DWARF 2
6200 GDB now includes basic Java language support. This support is
6201 only useful with Java compilers that produce native machine code.
6203 * solib-absolute-prefix and solib-search-path
6205 For SunOS and SVR4 shared libraries, you may now set the prefix for
6206 loading absolute shared library symbol files, and the search path for
6207 locating non-absolute shared library symbol files.
6209 * Live range splitting
6211 GDB can now effectively debug code for which GCC has performed live
6212 range splitting as part of its optimization. See gdb/doc/LRS for
6213 more details on the expected format of the stabs information.
6217 GDB's support for the GNU Hurd, including thread debugging, has been
6218 updated to work with current versions of the Hurd.
6222 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6223 instruction set. ARM GDB automatically detects when Thumb
6224 instructions are in use, and adjusts disassembly and backtracing
6229 GDB's MIPS target configurations now handle the MIP16 16-bit
6234 GDB now includes support for overlays; if an executable has been
6235 linked such that multiple sections are based at the same address, GDB
6236 will decide which section to use for symbolic info. You can choose to
6237 control the decision manually, using overlay commands, or implement
6238 additional target-side support and use "overlay load-target" to bring
6239 in the overlay mapping. Do "help overlay" for more detail.
6243 The command "info symbol <address>" displays information about
6244 the symbol at the specified address.
6248 The standard remote protocol now includes an extension that allows
6249 asynchronous collection and display of trace data. This requires
6250 extensive support in the target-side debugging stub. Tracing mode
6251 includes a new interaction mode in GDB and new commands: see the
6252 file tracepoint.c for more details.
6256 Configurations for embedded MIPS now include a simulator contributed
6257 by Cygnus Solutions. The simulator supports the instruction sets
6258 of most MIPS variants.
6262 Sparc configurations may now include the ERC32 simulator contributed
6263 by the European Space Agency. The simulator is not built into
6264 Sparc targets by default; configure with --enable-sim to include it.
6268 For target configurations that may include multiple variants of a
6269 basic architecture (such as MIPS and SH), you may now set the
6270 architecture explicitly. "set arch" sets, "info arch" lists
6271 the possible architectures.
6273 *** Changes in GDB-4.16:
6275 * New native configurations
6277 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6278 M68K NetBSD m68k-*-netbsd*
6279 PowerPC AIX 4.x powerpc-*-aix*
6280 PowerPC MacOS powerpc-*-macos*
6281 PowerPC Windows NT powerpcle-*-cygwin32
6282 RS/6000 AIX 4.x rs6000-*-aix4*
6286 ARM with RDP protocol arm-*-*
6287 I960 with MON960 i960-*-coff
6288 MIPS VxWorks mips*-*-vxworks*
6289 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6290 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6292 Matra Sparclet sparclet-*-*
6296 The powerpc-eabi configuration now includes the PSIM simulator,
6297 contributed by Andrew Cagney, with assistance from Mike Meissner.
6298 PSIM is a very elaborate model of the PowerPC, including not only
6299 basic instruction set execution, but also details of execution unit
6300 performance and I/O hardware. See sim/ppc/README for more details.
6304 GDB now works with Solaris 2.5.
6306 * Windows 95/NT native
6308 GDB will now work as a native debugger on Windows 95 and Windows NT.
6309 To build it from source, you must use the "gnu-win32" environment,
6310 which uses a DLL to emulate enough of Unix to run the GNU tools.
6311 Further information, binaries, and sources are available at
6312 ftp.cygnus.com, under pub/gnu-win32.
6314 * dont-repeat command
6316 If a user-defined command includes the command `dont-repeat', then the
6317 command will not be repeated if the user just types return. This is
6318 useful if the command is time-consuming to run, so that accidental
6319 extra keystrokes don't run the same command many times.
6321 * Send break instead of ^C
6323 The standard remote protocol now includes an option to send a break
6324 rather than a ^C to the target in order to interrupt it. By default,
6325 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6327 * Remote protocol timeout
6329 The standard remote protocol includes a new variable `remotetimeout'
6330 that allows you to set the number of seconds before GDB gives up trying
6331 to read from the target. The default value is 2.
6333 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6335 By default GDB will automatically keep track of objects as they are
6336 loaded and unloaded by the dynamic linker. By using the command `set
6337 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6338 when shared library events occur, thus allowing you to set breakpoints
6339 in shared libraries which are explicitly loaded by the inferior.
6341 Note this feature does not work on hpux8. On hpux9 you must link
6342 /usr/lib/end.o into your program. This feature should work
6343 automatically on hpux10.
6345 * Irix 5.x hardware watchpoint support
6347 Irix 5 configurations now support the use of hardware watchpoints.
6349 * Mips protocol "SYN garbage limit"
6351 When debugging a Mips target using the `target mips' protocol, you
6352 may set the number of characters that GDB will ignore by setting
6353 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6354 every character. The default value is 1050.
6356 * Recording and replaying remote debug sessions
6358 If you set `remotelogfile' to the name of a file, gdb will write to it
6359 a recording of a remote debug session. This recording may then be
6360 replayed back to gdb using "gdbreplay". See gdbserver/README for
6361 details. This is useful when you have a problem with GDB while doing
6362 remote debugging; you can make a recording of the session and send it
6363 to someone else, who can then recreate the problem.
6365 * Speedups for remote debugging
6367 GDB includes speedups for downloading and stepping MIPS systems using
6368 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6369 and more efficient S-record downloading.
6371 * Memory use reductions and statistics collection
6373 GDB now uses less memory and reports statistics about memory usage.
6374 Try the `maint print statistics' command, for example.
6376 *** Changes in GDB-4.15:
6378 * Psymtabs for XCOFF
6380 The symbol reader for AIX GDB now uses partial symbol tables. This
6381 can greatly improve startup time, especially for large executables.
6383 * Remote targets use caching
6385 Remote targets now use a data cache to speed up communication with the
6386 remote side. The data cache could lead to incorrect results because
6387 it doesn't know about volatile variables, thus making it impossible to
6388 debug targets which use memory mapped I/O devices. `set remotecache
6389 off' turns the the data cache off.
6391 * Remote targets may have threads
6393 The standard remote protocol now includes support for multiple threads
6394 in the target system, using new protocol commands 'H' and 'T'. See
6395 gdb/remote.c for details.
6399 If GDB is configured with `--enable-netrom', then it will include
6400 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6401 acts as though it is a bank of ROM on the target board, but you can
6402 write into it over the network. GDB's support consists only of
6403 support for fast loading into the emulated ROM; to debug, you must use
6404 another protocol, such as standard remote protocol. The usual
6405 sequence is something like
6407 target nrom <netrom-hostname>
6409 target remote <netrom-hostname>:1235
6413 GDB now includes support for the Apple Macintosh, as a host only. It
6414 may be run as either an MPW tool or as a standalone application, and
6415 it can debug through the serial port. All the usual GDB commands are
6416 available, but to the target command, you must supply "serial" as the
6417 device type instead of "/dev/ttyXX". See mpw-README in the main
6418 directory for more information on how to build. The MPW configuration
6419 scripts */mpw-config.in support only a few targets, and only the
6420 mips-idt-ecoff target has been tested.
6424 GDB configuration now uses autoconf. This is not user-visible,
6425 but does simplify configuration and building.
6429 GDB now supports hpux10.
6431 *** Changes in GDB-4.14:
6433 * New native configurations
6435 x86 FreeBSD i[345]86-*-freebsd
6436 x86 NetBSD i[345]86-*-netbsd
6437 NS32k NetBSD ns32k-*-netbsd
6438 Sparc NetBSD sparc-*-netbsd
6442 A29K VxWorks a29k-*-vxworks
6443 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6444 CPU32 EST-300 emulator m68*-*-est*
6445 PowerPC ELF powerpc-*-elf
6448 * Alpha OSF/1 support for procfs
6450 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6451 possible to attach to running processes. As the mounting of the /proc
6452 filesystem is optional on the Alpha, GDB automatically determines
6453 the availability of /proc during startup. This can lead to problems
6454 if /proc is unmounted after GDB has been started.
6456 * Arguments to user-defined commands
6458 User commands may accept up to 10 arguments separated by whitespace.
6459 Arguments are accessed within the user command via $arg0..$arg9. A
6462 print $arg0 + $arg1 + $arg2
6464 To execute the command use:
6467 Defines the command "adder" which prints the sum of its three arguments.
6468 Note the arguments are text substitutions, so they may reference variables,
6469 use complex expressions, or even perform inferior function calls.
6471 * New `if' and `while' commands
6473 This makes it possible to write more sophisticated user-defined
6474 commands. Both commands take a single argument, which is the
6475 expression to evaluate, and must be followed by the commands to
6476 execute, one per line, if the expression is nonzero, the list being
6477 terminated by the word `end'. The `if' command list may include an
6478 `else' word, which causes the following commands to be executed only
6479 if the expression is zero.
6481 * Fortran source language mode
6483 GDB now includes partial support for Fortran 77. It will recognize
6484 Fortran programs and can evaluate a subset of Fortran expressions, but
6485 variables and functions may not be handled correctly. GDB will work
6486 with G77, but does not yet know much about symbols emitted by other
6489 * Better HPUX support
6491 Most debugging facilities now work on dynamic executables for HPPAs
6492 running hpux9 or later. You can attach to running dynamically linked
6493 processes, but by default the dynamic libraries will be read-only, so
6494 for instance you won't be able to put breakpoints in them. To change
6495 that behavior do the following before running the program:
6501 This will cause the libraries to be mapped private and read-write.
6502 To revert to the normal behavior, do this:
6508 You cannot set breakpoints or examine data in the library until after
6509 the library is loaded if the function/data symbols do not have
6512 GDB can now also read debug symbols produced by the HP C compiler on
6513 HPPAs (sorry, no C++, Fortran or 68k support).
6515 * Target byte order now dynamically selectable
6517 You can choose which byte order to use with a target system, via the
6518 commands "set endian big" and "set endian little", and you can see the
6519 current setting by using "show endian". You can also give the command
6520 "set endian auto", in which case GDB will use the byte order
6521 associated with the executable. Currently, only embedded MIPS
6522 configurations support dynamic selection of target byte order.
6524 * New DOS host serial code
6526 This version uses DPMI interrupts to handle buffered I/O, so you
6527 no longer need to run asynctsr when debugging boards connected to
6530 *** Changes in GDB-4.13:
6532 * New "complete" command
6534 This lists all the possible completions for the rest of the line, if it
6535 were to be given as a command itself. This is intended for use by emacs.
6537 * Trailing space optional in prompt
6539 "set prompt" no longer adds a space for you after the prompt you set. This
6540 allows you to set a prompt which ends in a space or one that does not.
6542 * Breakpoint hit counts
6544 "info break" now displays a count of the number of times the breakpoint
6545 has been hit. This is especially useful in conjunction with "ignore"; you
6546 can ignore a large number of breakpoint hits, look at the breakpoint info
6547 to see how many times the breakpoint was hit, then run again, ignoring one
6548 less than that number, and this will get you quickly to the last hit of
6551 * Ability to stop printing at NULL character
6553 "set print null-stop" will cause GDB to stop printing the characters of
6554 an array when the first NULL is encountered. This is useful when large
6555 arrays actually contain only short strings.
6557 * Shared library breakpoints
6559 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6560 breakpoints in shared libraries before the executable is run.
6562 * Hardware watchpoints
6564 There is a new hardware breakpoint for the watch command for sparclite
6565 targets. See gdb/sparclite/hw_breakpoint.note.
6567 Hardware watchpoints are also now supported under GNU/Linux.
6571 Annotations have been added. These are for use with graphical interfaces,
6572 and are still experimental. Currently only gdba.el uses these.
6574 * Improved Irix 5 support
6576 GDB now works properly with Irix 5.2.
6578 * Improved HPPA support
6580 GDB now works properly with the latest GCC and GAS.
6582 * New native configurations
6584 Sequent PTX4 i[34]86-sequent-ptx4
6585 HPPA running OSF/1 hppa*-*-osf*
6586 Atari TT running SVR4 m68*-*-sysv4*
6587 RS/6000 LynxOS rs6000-*-lynxos*
6591 OS/9000 i[34]86-*-os9k
6592 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6595 * Hitachi SH7000 and E7000-PC ICE support
6597 There is now support for communicating with the Hitachi E7000-PC ICE.
6598 This is available automatically when GDB is configured for the SH.
6602 As usual, a variety of small fixes and improvements, both generic
6603 and configuration-specific. See the ChangeLog for more detail.
6605 *** Changes in GDB-4.12:
6607 * Irix 5 is now supported
6611 GDB-4.12 on the HPPA has a number of changes which make it unable
6612 to debug the output from the currently released versions of GCC and
6613 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6614 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6615 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6618 *** Changes in GDB-4.11:
6620 * User visible changes:
6624 The "set remotedebug" option is now consistent between the mips remote
6625 target, remote targets using the gdb-specific protocol, UDI (AMD's
6626 debug protocol for the 29k) and the 88k bug monitor. It is now an
6627 integer specifying a debug level (normally 0 or 1, but 2 means more
6628 debugging info for the mips target).
6630 * DEC Alpha native support
6632 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6633 debug info, but GDB works fairly well with the DEC compiler and should
6634 work with a future GCC release. See the README file for a few
6635 Alpha-specific notes.
6637 * Preliminary thread implementation
6639 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6641 * LynxOS native and target support for 386
6643 This release has been hosted on LynxOS 2.2, and also can be configured
6644 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6647 * Improvements in C++ mangling/demangling.
6649 This release has much better g++ debugging, specifically in name
6650 mangling/demangling, virtual function calls, print virtual table,
6651 call methods, ...etc.
6653 *** Changes in GDB-4.10:
6655 * User visible changes:
6657 Remote debugging using the GDB-specific (`target remote') protocol now
6658 supports the `load' command. This is only useful if you have some
6659 other way of getting the stub to the target system, and you can put it
6660 somewhere in memory where it won't get clobbered by the download.
6662 Filename completion now works.
6664 When run under emacs mode, the "info line" command now causes the
6665 arrow to point to the line specified. Also, "info line" prints
6666 addresses in symbolic form (as well as hex).
6668 All vxworks based targets now support a user settable option, called
6669 vxworks-timeout. This option represents the number of seconds gdb
6670 should wait for responses to rpc's. You might want to use this if
6671 your vxworks target is, perhaps, a slow software simulator or happens
6672 to be on the far side of a thin network line.
6676 This release contains support for using a DEC alpha as a GDB host for
6677 cross debugging. Native alpha debugging is not supported yet.
6680 *** Changes in GDB-4.9:
6684 This is the first GDB release which is accompanied by a matching testsuite.
6685 The testsuite requires installation of dejagnu, which should be available
6686 via ftp from most sites that carry GNU software.
6690 'Cfront' style demangling has had its name changed to 'ARM' style, to
6691 emphasize that it was written from the specifications in the C++ Annotated
6692 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6693 disclaimers, it still generated too much confusion with users attempting to
6694 use gdb with AT&T cfront.
6698 GDB now uses a standard remote interface to a simulator library.
6699 So far, the library contains simulators for the Zilog Z8001/2, the
6700 Hitachi H8/300, H8/500 and Super-H.
6702 * New targets supported
6704 H8/300 simulator h8300-hitachi-hms or h8300hms
6705 H8/500 simulator h8500-hitachi-hms or h8500hms
6706 SH simulator sh-hitachi-hms or sh
6707 Z8000 simulator z8k-zilog-none or z8ksim
6708 IDT MIPS board over serial line mips-idt-ecoff
6710 Cross-debugging to GO32 targets is supported. It requires a custom
6711 version of the i386-stub.c module which is integrated with the
6712 GO32 memory extender.
6714 * New remote protocols
6716 MIPS remote debugging protocol.
6718 * New source languages supported
6720 This version includes preliminary support for Chill, a Pascal like language
6721 used by telecommunications companies. Chill support is also being integrated
6722 into the GNU compiler, but we don't know when it will be publically available.
6725 *** Changes in GDB-4.8:
6727 * HP Precision Architecture supported
6729 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6730 version of this support was available as a set of patches from the
6731 University of Utah. GDB does not support debugging of programs
6732 compiled with the HP compiler, because HP will not document their file
6733 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6734 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6736 Many problems in the preliminary version have been fixed.
6738 * Faster and better demangling
6740 We have improved template demangling and fixed numerous bugs in the GNU style
6741 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6742 character types (wchar_t) are now supported. Demangling of each symbol is now
6743 only done once, and is cached when the symbol table for a file is read in.
6744 This results in a small increase in memory usage for C programs, a moderate
6745 increase in memory usage for C++ programs, and a fantastic speedup in
6748 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6749 from the specifications in the Annotated Reference Manual, which AT&T's
6750 compiler does not actually implement.
6752 * G++ multiple inheritance compiler problem
6754 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6755 inheritance lattices was reworked to properly discover ambiguities. We
6756 recently found an example which causes this new algorithm to fail in a
6757 very subtle way, producing bad debug information for those classes.
6758 The file 'gcc.patch' (in this directory) can be applied to gcc to
6759 circumvent the problem. A future GCC release will contain a complete
6762 The previous G++ debug info problem (mentioned below for the gdb-4.7
6763 release) is fixed in gcc version 2.3.2.
6765 * Improved configure script
6767 The `configure' script will now attempt to guess your system type if
6768 you don't supply a host system type. The old scheme of supplying a
6769 host system triplet is preferable over using this. All the magic is
6770 done in the new `config.guess' script. Examine it for details.
6772 We have also brought our configure script much more in line with the FSF's
6773 version. It now supports the --with-xxx options. In particular,
6774 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6775 The resulting GDB will not be able to read arbitrary object file formats --
6776 only the format ``expected'' to be used on the configured target system.
6777 We hope to make this the default in a future release.
6779 * Documentation improvements
6781 There's new internal documentation on how to modify GDB, and how to
6782 produce clean changes to the code. We implore people to read it
6783 before submitting changes.
6785 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6786 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6787 `info' files are also provided. To build `info' files from scratch,
6788 you will need the latest `makeinfo' release, which will be available in
6789 a future texinfo-X.Y release.
6791 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6792 We're not sure exactly which versions have this problem, but it has
6793 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6794 or better. If that isn't possible, there is a patch in
6795 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6796 around this problem.
6800 GDB now supports array constants that can be used in expressions typed in by
6801 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6802 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6805 The new directory `gdb/sparclite' contains a program that demonstrates
6806 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6808 * New native hosts supported
6810 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6811 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6813 * New targets supported
6815 AMD 29k family via UDI a29k-amd-udi or udi29k
6817 * New file formats supported
6819 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6820 HPUX core files, and SCO 3.2v2 core files.
6824 Attaching to processes now works again; thanks for the many bug reports.
6826 We have also stomped on a bunch of core dumps caused by
6827 printf_filtered("%s") problems.
6829 We eliminated a copyright problem on the rpc and ptrace header files
6830 for VxWorks, which was discovered at the last minute during the 4.7
6831 release. You should now be able to build a VxWorks GDB.
6833 You can now interrupt gdb while an attached process is running. This
6834 will cause the attached process to stop, and give control back to GDB.
6836 We fixed problems caused by using too many file descriptors
6837 for reading symbols from object files and libraries. This was
6838 especially a problem for programs that used many (~100) shared
6841 The `step' command now only enters a subroutine if there is line number
6842 information for the subroutine. Otherwise it acts like the `next'
6843 command. Previously, `step' would enter subroutines if there was
6844 any debugging information about the routine. This avoids problems
6845 when using `cc -g1' on MIPS machines.
6847 * Internal improvements
6849 GDB's internal interfaces have been improved to make it easier to support
6850 debugging of multiple languages in the future.
6852 GDB now uses a common structure for symbol information internally.
6853 Minimal symbols (derived from linkage symbols in object files), partial
6854 symbols (from a quick scan of debug information), and full symbols
6855 contain a common subset of information, making it easier to write
6856 shared code that handles any of them.
6858 * New command line options
6860 We now accept --silent as an alias for --quiet.
6864 The memory-mapped-malloc library is now licensed under the GNU Library
6865 General Public License.
6867 *** Changes in GDB-4.7:
6869 * Host/native/target split
6871 GDB has had some major internal surgery to untangle the support for
6872 hosts and remote targets. Now, when you configure GDB for a remote
6873 target, it will no longer load in all of the support for debugging
6874 local programs on the host. When fully completed and tested, this will
6875 ensure that arbitrary host/target combinations are possible.
6877 The primary conceptual shift is to separate the non-portable code in
6878 GDB into three categories. Host specific code is required any time GDB
6879 is compiled on that host, regardless of the target. Target specific
6880 code relates to the peculiarities of the target, but can be compiled on
6881 any host. Native specific code is everything else: it can only be
6882 built when the host and target are the same system. Child process
6883 handling and core file support are two common `native' examples.
6885 GDB's use of /proc for controlling Unix child processes is now cleaner.
6886 It has been split out into a single module under the `target_ops' vector,
6887 plus two native-dependent functions for each system that uses /proc.
6889 * New hosts supported
6891 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6892 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6893 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6895 * New targets supported
6897 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6898 68030 and CPU32 m68030-*-*, m68332-*-*
6900 * New native hosts supported
6902 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6903 (386bsd is not well tested yet)
6904 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6906 * New file formats supported
6908 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6909 supports reading of `a.out.adobe' object files, which are an a.out
6910 format extended with minimal information about multiple sections.
6914 `show copying' is the same as the old `info copying'.
6915 `show warranty' is the same as `info warrantee'.
6916 These were renamed for consistency. The old commands continue to work.
6918 `info handle' is a new alias for `info signals'.
6920 You can now define pre-command hooks, which attach arbitrary command
6921 scripts to any command. The commands in the hook will be executed
6922 prior to the user's command. You can also create a hook which will be
6923 executed whenever the program stops. See gdb.texinfo.
6927 We now deal with Cfront style name mangling, and can even extract type
6928 info from mangled symbols. GDB can automatically figure out which
6929 symbol mangling style your C++ compiler uses.
6931 Calling of methods and virtual functions has been improved as well.
6935 The crash that occured when debugging Sun Ansi-C compiled binaries is
6936 fixed. This was due to mishandling of the extra N_SO stabs output
6939 We also finally got Ultrix 4.2 running in house, and fixed core file
6940 support, with help from a dozen people on the net.
6942 John M. Farrell discovered that the reason that single-stepping was so
6943 slow on all of the Mips based platforms (primarily SGI and DEC) was
6944 that we were trying to demangle and lookup a symbol used for internal
6945 purposes on every instruction that was being stepped through. Changing
6946 the name of that symbol so that it couldn't be mistaken for a C++
6947 mangled symbol sped things up a great deal.
6949 Rich Pixley sped up symbol lookups in general by getting much smarter
6950 about when C++ symbol mangling is necessary. This should make symbol
6951 completion (TAB on the command line) much faster. It's not as fast as
6952 we'd like, but it's significantly faster than gdb-4.6.
6956 A new user controllable variable 'call_scratch_address' can
6957 specify the location of a scratch area to be used when GDB
6958 calls a function in the target. This is necessary because the
6959 usual method of putting the scratch area on the stack does not work
6960 in systems that have separate instruction and data spaces.
6962 We integrated changes to support the 29k UDI (Universal Debugger
6963 Interface), but discovered at the last minute that we didn't have all
6964 of the appropriate copyright paperwork. We are working with AMD to
6965 resolve this, and hope to have it available soon.
6969 We have sped up the remote serial line protocol, especially for targets
6970 with lots of registers. It now supports a new `expedited status' ('T')
6971 message which can be used in place of the existing 'S' status message.
6972 This allows the remote stub to send only the registers that GDB
6973 needs to make a quick decision about single-stepping or conditional
6974 breakpoints, eliminating the need to fetch the entire register set for
6975 each instruction being stepped through.
6977 The GDB remote serial protocol now implements a write-through cache for
6978 registers, only re-reading the registers if the target has run.
6980 There is also a new remote serial stub for SPARC processors. You can
6981 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6982 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6983 processor with a serial port.
6987 Configure.in files have become much easier to read and modify. A new
6988 `table driven' format makes it more obvious what configurations are
6989 supported, and what files each one uses.
6993 There is a new opcodes library which will eventually contain all of the
6994 disassembly routines and opcode tables. At present, it only contains
6995 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6996 disassembler (binutils/objdump) to share these routines.
6998 The libiberty library is now copylefted under the GNU Library General
6999 Public License. This allows more liberal use, and was done so libg++
7000 can use it. This makes no difference to GDB, since the Library License
7001 grants all the rights from the General Public License.
7005 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7006 reference to the stabs symbol info used by the debugger. It is (as far
7007 as we know) the only published document on this fascinating topic. We
7008 encourage you to read it, compare it to the stabs information on your
7009 system, and send improvements on the document in general (to
7010 bug-gdb@prep.ai.mit.edu).
7012 And, of course, many bugs have been fixed.
7015 *** Changes in GDB-4.6:
7017 * Better support for C++ function names
7019 GDB now accepts as input the "demangled form" of C++ overloaded function
7020 names and member function names, and can do command completion on such names
7021 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7022 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7023 Make use of command completion, it is your friend.
7025 GDB also now accepts a variety of C++ mangled symbol formats. They are
7026 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7027 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7028 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7029 for the list of formats.
7031 * G++ symbol mangling problem
7033 Recent versions of gcc have a bug in how they emit debugging information for
7034 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7035 directory) can be applied to gcc to fix the problem. Alternatively, if you
7036 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7037 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7038 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7041 * New 'maintenance' command
7043 All of the commands related to hacking GDB internals have been moved out of
7044 the main command set, and now live behind the 'maintenance' command. This
7045 can also be abbreviated as 'mt'. The following changes were made:
7047 dump-me -> maintenance dump-me
7048 info all-breakpoints -> maintenance info breakpoints
7049 printmsyms -> maintenance print msyms
7050 printobjfiles -> maintenance print objfiles
7051 printpsyms -> maintenance print psymbols
7052 printsyms -> maintenance print symbols
7054 The following commands are new:
7056 maintenance demangle Call internal GDB demangler routine to
7057 demangle a C++ link name and prints the result.
7058 maintenance print type Print a type chain for a given symbol
7060 * Change to .gdbinit file processing
7062 We now read the $HOME/.gdbinit file before processing the argv arguments
7063 (e.g. reading symbol files or core files). This allows global parameters to
7064 be set, which will apply during the symbol reading. The ./.gdbinit is still
7065 read after argv processing.
7067 * New hosts supported
7069 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7071 GNU/Linux support i386-unknown-linux or linux
7073 We are also including code to support the HP/PA running BSD and HPUX. This
7074 is almost guaranteed not to work, as we didn't have time to test or build it
7075 for this release. We are including it so that the more adventurous (or
7076 masochistic) of you can play with it. We also had major problems with the
7077 fact that the compiler that we got from HP doesn't support the -g option.
7080 * New targets supported
7082 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7084 * More smarts about finding #include files
7086 GDB now remembers the compilation directory for all include files, and for
7087 all files from which C is generated (like yacc and lex sources). This
7088 greatly improves GDB's ability to find yacc/lex sources, and include files,
7089 especially if you are debugging your program from a directory different from
7090 the one that contains your sources.
7092 We also fixed a bug which caused difficulty with listing and setting
7093 breakpoints in include files which contain C code. (In the past, you had to
7094 try twice in order to list an include file that you hadn't looked at before.)
7096 * Interesting infernals change
7098 GDB now deals with arbitrary numbers of sections, where the symbols for each
7099 section must be relocated relative to that section's landing place in the
7100 target's address space. This work was needed to support ELF with embedded
7101 stabs used by Solaris-2.0.
7103 * Bug fixes (of course!)
7105 There have been loads of fixes for the following things:
7106 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7107 i960, stabs, DOS(GO32), procfs, etc...
7109 See the ChangeLog for details.
7111 *** Changes in GDB-4.5:
7113 * New machines supported (host and target)
7115 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7117 SGI Irix-4.x mips-sgi-irix4 or iris4
7119 * New malloc package
7121 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7122 Mmalloc is capable of handling mutiple heaps of memory. It is also
7123 capable of saving a heap to a file, and then mapping it back in later.
7124 This can be used to greatly speedup the startup of GDB by using a
7125 pre-parsed symbol table which lives in a mmalloc managed heap. For
7126 more details, please read mmalloc/mmalloc.texi.
7130 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7131 'help info proc' for details.
7133 * MIPS ecoff symbol table format
7135 The code that reads MIPS symbol table format is now supported on all hosts.
7136 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7139 * File name changes for MS-DOS
7141 Many files in the config directories have been renamed to make it easier to
7142 support GDB on MS-DOSe systems (which have very restrictive file name
7143 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7144 environment) is close to working but has some remaining problems. Note
7145 that debugging of DOS programs is not supported, due to limitations
7146 in the ``operating system'', but it can be used to host cross-debugging.
7148 * Cross byte order fixes
7150 Many fixes have been made to support cross debugging of Sparc and MIPS
7151 targets from hosts whose byte order differs.
7153 * New -mapped and -readnow options
7155 If memory-mapped files are available on your system through the 'mmap'
7156 system call, you can use the -mapped option on the `file' or
7157 `symbol-file' commands to cause GDB to write the symbols from your
7158 program into a reusable file. If the program you are debugging is
7159 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7160 Future GDB debugging sessions will notice the presence of this file,
7161 and will quickly map in symbol information from it, rather than reading
7162 the symbol table from the executable program. Using the '-mapped'
7163 option in a GDB `file' or `symbol-file' command has the same effect as
7164 starting GDB with the '-mapped' command-line option.
7166 You can cause GDB to read the entire symbol table immediately by using
7167 the '-readnow' option with any of the commands that load symbol table
7168 information (or on the GDB command line). This makes the command
7169 slower, but makes future operations faster.
7171 The -mapped and -readnow options are typically combined in order to
7172 build a `fred.syms' file that contains complete symbol information.
7173 A simple GDB invocation to do nothing but build a `.syms' file for future
7176 gdb -batch -nx -mapped -readnow programname
7178 The `.syms' file is specific to the host machine on which GDB is run.
7179 It holds an exact image of GDB's internal symbol table. It cannot be
7180 shared across multiple host platforms.
7182 * longjmp() handling
7184 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7185 siglongjmp() without losing control. This feature has not yet been ported to
7186 all systems. It currently works on many 386 platforms, all MIPS-based
7187 platforms (SGI, DECstation, etc), and Sun3/4.
7191 Preliminary work has been put in to support the new Solaris OS from Sun. At
7192 this time, it can control and debug processes, but it is not capable of
7197 As always, many many bug fixes. The major areas were with g++, and mipsread.
7198 People using the MIPS-based platforms should experience fewer mysterious
7199 crashes and trashed symbol tables.
7201 *** Changes in GDB-4.4:
7203 * New machines supported (host and target)
7205 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7207 BSD Reno on Vax vax-dec-bsd
7208 Ultrix on Vax vax-dec-ultrix
7210 * New machines supported (target)
7212 AMD 29000 embedded, using EBMON a29k-none-none
7216 GDB continues to improve its handling of C++. `References' work better.
7217 The demangler has also been improved, and now deals with symbols mangled as
7218 per the Annotated C++ Reference Guide.
7220 GDB also now handles `stabs' symbol information embedded in MIPS
7221 `ecoff' symbol tables. Since the ecoff format was not easily
7222 extensible to handle new languages such as C++, this appeared to be a
7223 good way to put C++ debugging info into MIPS binaries. This option
7224 will be supported in the GNU C compiler, version 2, when it is
7227 * New features for SVR4
7229 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7230 shared libraries. Debugging dynamically linked programs should present
7231 only minor differences from debugging statically linked programs.
7233 The `info proc' command will print out information about any process
7234 on an SVR4 system (including the one you are debugging). At the moment,
7235 it prints the address mappings of the process.
7237 If you bring up GDB on another SVR4 system, please send mail to
7238 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7240 * Better dynamic linking support in SunOS
7242 Reading symbols from shared libraries which contain debugging symbols
7243 now works properly. However, there remain issues such as automatic
7244 skipping of `transfer vector' code during function calls, which
7245 make it harder to debug code in a shared library, than to debug the
7246 same code linked statically.
7250 GDB is now using the latest `getopt' routines from the FSF. This
7251 version accepts the -- prefix for options with long names. GDB will
7252 continue to accept the old forms (-option and +option) as well.
7253 Various single letter abbreviations for options have been explicity
7254 added to the option table so that they won't get overshadowed in the
7255 future by other options that begin with the same letter.
7259 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7260 Many assorted bugs have been handled. Many more remain to be handled.
7261 See the various ChangeLog files (primarily in gdb and bfd) for details.
7264 *** Changes in GDB-4.3:
7266 * New machines supported (host and target)
7268 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7269 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7270 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7272 * Almost SCO Unix support
7274 We had hoped to support:
7275 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7276 (except for core file support), but we discovered very late in the release
7277 that it has problems with process groups that render gdb unusable. Sorry
7278 about that. I encourage people to fix it and post the fixes.
7280 * Preliminary ELF and DWARF support
7282 GDB can read ELF object files on System V Release 4, and can handle
7283 debugging records for C, in DWARF format, in ELF files. This support
7284 is preliminary. If you bring up GDB on another SVR4 system, please
7285 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7290 GDB now uses the latest `readline' library. One user-visible change
7291 is that two tabs will list possible command completions, which previously
7292 required typing M-? (meta-question mark, or ESC ?).
7296 The `stepi' bug that many of you noticed has been squashed.
7297 Many bugs in C++ have been handled. Many more remain to be handled.
7298 See the various ChangeLog files (primarily in gdb and bfd) for details.
7300 * State of the MIPS world (in case you wondered):
7302 GDB can understand the symbol tables emitted by the compilers
7303 supplied by most vendors of MIPS-based machines, including DEC. These
7304 symbol tables are in a format that essentially nobody else uses.
7306 Some versions of gcc come with an assembler post-processor called
7307 mips-tfile. This program is required if you want to do source-level
7308 debugging of gcc-compiled programs. I believe FSF does not ship
7309 mips-tfile with gcc version 1, but it will eventually come with gcc
7312 Debugging of g++ output remains a problem. g++ version 1.xx does not
7313 really support it at all. (If you're lucky, you should be able to get
7314 line numbers and stack traces to work, but no parameters or local
7315 variables.) With some work it should be possible to improve the
7318 When gcc version 2 is released, you will have somewhat better luck.
7319 However, even then you will get confusing results for inheritance and
7322 We will eventually provide full debugging of g++ output on
7323 DECstations. This will probably involve some kind of stabs-in-ecoff
7324 encapulation, but the details have not been worked out yet.
7327 *** Changes in GDB-4.2:
7329 * Improved configuration
7331 Only one copy of `configure' exists now, and it is not self-modifying.
7332 Porting BFD is simpler.
7336 The `step' and `next' commands now only stop at the first instruction
7337 of a source line. This prevents the multiple stops that used to occur
7338 in switch statements, for-loops, etc. `Step' continues to stop if a
7339 function that has debugging information is called within the line.
7343 Lots of small bugs fixed. More remain.
7345 * New host supported (not target)
7347 Intel 386 PC clone running Mach i386-none-mach
7350 *** Changes in GDB-4.1:
7352 * Multiple source language support
7354 GDB now has internal scaffolding to handle several source languages.
7355 It determines the type of each source file from its filename extension,
7356 and will switch expression parsing and number formatting to match the
7357 language of the function in the currently selected stack frame.
7358 You can also specifically set the language to be used, with
7359 `set language c' or `set language modula-2'.
7363 GDB now has preliminary support for the GNU Modula-2 compiler,
7364 currently under development at the State University of New York at
7365 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7366 continue through the fall of 1991 and into 1992.
7368 Other Modula-2 compilers are currently not supported, and attempting to
7369 debug programs compiled with them will likely result in an error as the
7370 symbol table is read. Feel free to work on it, though!
7372 There are hooks in GDB for strict type checking and range checking,
7373 in the `Modula-2 philosophy', but they do not currently work.
7377 GDB can now write to executable and core files (e.g. patch
7378 a variable's value). You must turn this switch on, specify
7379 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7380 by assigning a new value to a variable. Modifications take
7383 * Automatic SunOS shared library reading
7385 When you run your program, GDB automatically determines where its
7386 shared libraries (if any) have been loaded, and reads their symbols.
7387 The `share' command is no longer needed. This also works when
7388 examining core files.
7392 You can specify the number of lines that the `list' command shows.
7395 * New machines supported (host and target)
7397 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7398 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7399 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7401 * New hosts supported (not targets)
7403 IBM RT/PC: romp-ibm-aix or rtpc
7405 * New targets supported (not hosts)
7407 AMD 29000 embedded with COFF a29k-none-coff
7408 AMD 29000 embedded with a.out a29k-none-aout
7409 Ultracomputer remote kernel debug a29k-nyu-kern
7411 * New remote interfaces
7417 *** Changes in GDB-4.0:
7421 Wide output is wrapped at good places to make the output more readable.
7423 Gdb now supports cross-debugging from a host machine of one type to a
7424 target machine of another type. Communication with the target system
7425 is over serial lines. The ``target'' command handles connecting to the
7426 remote system; the ``load'' command will download a program into the
7427 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7428 also supports debugging of realtime processes running under VxWorks,
7429 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7430 stub on the target system.
7432 New CPUs supported include the AMD 29000 and Intel 960.
7434 GDB now reads object files and symbol tables via a ``binary file''
7435 library, which allows a single copy of GDB to debug programs of multiple
7436 object file types such as a.out and coff.
7438 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7439 refcard.dvi and refcard.ps are available to format it).
7442 * Control-Variable user interface simplified
7444 All variables that control the operation of the debugger can be set
7445 by the ``set'' command, and displayed by the ``show'' command.
7447 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7448 ``Show prompt'' produces the response:
7449 Gdb's prompt is new-gdb=>.
7451 What follows are the NEW set commands. The command ``help set'' will
7452 print a complete list of old and new set commands. ``help set FOO''
7453 will give a longer description of the variable FOO. ``show'' will show
7454 all of the variable descriptions and their current settings.
7456 confirm on/off: Enables warning questions for operations that are
7457 hard to recover from, e.g. rerunning the program while
7458 it is already running. Default is ON.
7460 editing on/off: Enables EMACS style command line editing
7461 of input. Previous lines can be recalled with
7462 control-P, the current line can be edited with control-B,
7463 you can search for commands with control-R, etc.
7466 history filename NAME: NAME is where the gdb command history
7467 will be stored. The default is .gdb_history,
7468 or the value of the environment variable
7471 history size N: The size, in commands, of the command history. The
7472 default is 256, or the value of the environment variable
7475 history save on/off: If this value is set to ON, the history file will
7476 be saved after exiting gdb. If set to OFF, the
7477 file will not be saved. The default is OFF.
7479 history expansion on/off: If this value is set to ON, then csh-like
7480 history expansion will be performed on
7481 command line input. The default is OFF.
7483 radix N: Sets the default radix for input and output. It can be set
7484 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7485 in the current radix, so "set radix 10" is always a no-op.
7487 height N: This integer value is the number of lines on a page. Default
7488 is 24, the current `stty rows'' setting, or the ``li#''
7489 setting from the termcap entry matching the environment
7492 width N: This integer value is the number of characters on a line.
7493 Default is 80, the current `stty cols'' setting, or the ``co#''
7494 setting from the termcap entry matching the environment
7497 Note: ``set screensize'' is obsolete. Use ``set height'' and
7498 ``set width'' instead.
7500 print address on/off: Print memory addresses in various command displays,
7501 such as stack traces and structure values. Gdb looks
7502 more ``symbolic'' if you turn this off; it looks more
7503 ``machine level'' with it on. Default is ON.
7505 print array on/off: Prettyprint arrays. New convenient format! Default
7508 print demangle on/off: Print C++ symbols in "source" form if on,
7511 print asm-demangle on/off: Same, for assembler level printouts
7514 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7517 * Support for Epoch Environment.
7519 The epoch environment is a version of Emacs v18 with windowing. One
7520 new command, ``inspect'', is identical to ``print'', except that if you
7521 are running in the epoch environment, the value is printed in its own
7525 * Support for Shared Libraries
7527 GDB can now debug programs and core files that use SunOS shared libraries.
7528 Symbols from a shared library cannot be referenced
7529 before the shared library has been linked with the program (this
7530 happens after you type ``run'' and before the function main() is entered).
7531 At any time after this linking (including when examining core files
7532 from dynamically linked programs), gdb reads the symbols from each
7533 shared library when you type the ``sharedlibrary'' command.
7534 It can be abbreviated ``share''.
7536 sharedlibrary REGEXP: Load shared object library symbols for files
7537 matching a unix regular expression. No argument
7538 indicates to load symbols for all shared libraries.
7540 info sharedlibrary: Status of loaded shared libraries.
7545 A watchpoint stops execution of a program whenever the value of an
7546 expression changes. Checking for this slows down execution
7547 tremendously whenever you are in the scope of the expression, but is
7548 quite useful for catching tough ``bit-spreader'' or pointer misuse
7549 problems. Some machines such as the 386 have hardware for doing this
7550 more quickly, and future versions of gdb will use this hardware.
7552 watch EXP: Set a watchpoint (breakpoint) for an expression.
7554 info watchpoints: Information about your watchpoints.
7556 delete N: Deletes watchpoint number N (same as breakpoints).
7557 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7558 enable N: Re-enables watchpoint number N (same as breakpoints).
7561 * C++ multiple inheritance
7563 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7566 * C++ exception handling
7568 Gdb now supports limited C++ exception handling. Besides the existing
7569 ability to breakpoint on an exception handler, gdb can breakpoint on
7570 the raising of an exception (before the stack is peeled back to the
7573 catch FOO: If there is a FOO exception handler in the dynamic scope,
7574 set a breakpoint to catch exceptions which may be raised there.
7575 Multiple exceptions (``catch foo bar baz'') may be caught.
7577 info catch: Lists all exceptions which may be caught in the
7578 current stack frame.
7581 * Minor command changes
7583 The command ``call func (arg, arg, ...)'' now acts like the print
7584 command, except it does not print or save a value if the function's result
7585 is void. This is similar to dbx usage.
7587 The ``up'' and ``down'' commands now always print the frame they end up
7588 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7589 frames without printing.
7591 * New directory command
7593 'dir' now adds directories to the FRONT of the source search path.
7594 The path starts off empty. Source files that contain debug information
7595 about the directory in which they were compiled can be found even
7596 with an empty path; Sun CC and GCC include this information. If GDB can't
7597 find your source file in the current directory, type "dir .".
7599 * Configuring GDB for compilation
7601 For normal use, type ``./configure host''. See README or gdb.texinfo
7604 GDB now handles cross debugging. If you are remotely debugging between
7605 two different machines, type ``./configure host -target=targ''.
7606 Host is the machine where GDB will run; targ is the machine
7607 where the program that you are debugging will run.