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 ** Backtraces and frames include a new optional field addr_flags which is
293 given after the addr field. On AArch64 this contains PAC if the address
294 has been masked in the frame. On all other targets the field is not
299 The testsuite now creates the files gdb.cmd (containing the arguments
300 used to launch GDB) and gdb.in (containing all the commands sent to
301 GDB) in the output directory for each test script. Multiple invocations
302 are appended with .1, .2, .3 etc.
304 * Building GDB and GDBserver now requires GNU make >= 3.82.
306 Using another implementation of the make program or an earlier version of
307 GNU make to build GDB or GDBserver is not supported.
309 * Building GDB now requires GNU readline >= 7.0.
311 GDB now bundles GNU readline 8.0, but if you choose to use
312 --with-system-readline, only readline >= 7.0 can be used.
314 *** Changes in GDB 8.3
316 * GDB and GDBserver now support access to additional registers on
317 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
320 * GDB now has experimental support for the compilation and injection of
321 C++ source code into the inferior. This beta release does not include
322 support for several language features, such as templates, constructors,
325 This feature requires GCC 7.1 or higher built with libcp1.so
328 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
329 can be passed using the '[ADDRESS]:PORT' notation, or the regular
330 'ADDRESS:PORT' method.
332 * DWARF index cache: GDB can now automatically save indices of DWARF
333 symbols on disk to speed up further loading of the same binaries.
335 * Ada task switching is now supported on aarch64-elf targets when
336 debugging a program using the Ravenscar Profile. For more information,
337 see the "Tasking Support when using the Ravenscar Profile" section
338 in the GDB user manual.
340 * GDB in batch mode now exits with status 1 if the last command to be
343 * The RISC-V target now supports target descriptions.
345 * System call catchpoints now support system call aliases on FreeBSD.
346 When the ABI of a system call changes in FreeBSD, this is
347 implemented by leaving a compatibility system call using the old ABI
348 at the existing number and allocating a new system call number for
349 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
350 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
351 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
352 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
353 so that a system call catchpoint for the 'kevent' system call will
354 catch invocations of both the 'kevent' and 'freebsd11_kevent'
355 binaries. This ensures that 'kevent' system calls are caught for
356 binaries using either the old or new ABIs.
358 * Terminal styling is now available for the CLI and the TUI. GNU
359 Source Highlight can additionally be used to provide styling of
360 source code snippets. See the "set style" commands, below, for more
363 * Removed support for old demangling styles arm, edg, gnu, hp and
368 set debug compile-cplus-types
369 show debug compile-cplus-types
370 Control the display of debug output about type conversion in the
371 C++ compile feature. Commands have no effect while compiliong
376 Control whether debug output about files/functions skipping is
379 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
380 Apply a command to some frames.
381 FLAG arguments allow to control what output to produce and how to handle
382 errors raised when applying COMMAND to a frame.
385 Apply a command to all threads (ignoring errors and empty output).
386 Shortcut for 'thread apply all -s COMMAND'.
389 Apply a command to all frames (ignoring errors and empty output).
390 Shortcut for 'frame apply all -s COMMAND'.
393 Apply a command to all frames of all threads (ignoring errors and empty
395 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
397 maint set dwarf unwinders (on|off)
398 maint show dwarf unwinders
399 Control whether DWARF unwinders can be used.
402 Display a list of open files for a process.
406 Changes to the "frame", "select-frame", and "info frame" CLI commands.
407 These commands all now take a frame specification which
408 is either a frame level, or one of the keywords 'level', 'address',
409 'function', or 'view' followed by a parameter. Selecting a frame by
410 address, or viewing a frame outside the current backtrace now
411 requires the use of a keyword. Selecting a frame by level is
412 unchanged. The MI comment "-stack-select-frame" is unchanged.
414 target remote FILENAME
415 target extended-remote FILENAME
416 If FILENAME is a Unix domain socket, GDB will attempt to connect
417 to this socket instead of opening FILENAME as a character device.
419 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
420 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
421 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
422 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
423 These commands can now print only the searched entities
424 matching the provided regexp(s), giving a condition
425 on the entity names or entity types. The flag -q disables
426 printing headers or informations messages.
432 These commands now determine the syntax for the shown entities
433 according to the language chosen by `set language'. In particular,
434 `set language auto' means to automatically choose the language of
437 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
438 The 'thread apply' command accepts new FLAG arguments.
439 FLAG arguments allow to control what output to produce and how to handle
440 errors raised when applying COMMAND to a thread.
442 set tui tab-width NCHARS
443 show tui tab-width NCHARS
444 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
446 set style enabled [on|off]
448 Enable or disable terminal styling. Styling is enabled by default
449 on most hosts, but disabled by default when in batch mode.
451 set style sources [on|off]
453 Enable or disable source code styling. Source code styling is
454 enabled by default, but only takes effect if styling in general is
455 enabled, and if GDB was linked with GNU Source Highlight.
457 set style filename foreground COLOR
458 set style filename background COLOR
459 set style filename intensity VALUE
460 Control the styling of file names.
462 set style function foreground COLOR
463 set style function background COLOR
464 set style function intensity VALUE
465 Control the styling of function names.
467 set style variable foreground COLOR
468 set style variable background COLOR
469 set style variable intensity VALUE
470 Control the styling of variable names.
472 set style address foreground COLOR
473 set style address background COLOR
474 set style address intensity VALUE
475 Control the styling of addresses.
479 ** The default version of the MI interpreter is now 3 (-i=mi3).
481 ** The '-data-disassemble' MI command now accepts an '-a' option to
482 disassemble the whole function surrounding the given program
483 counter value or function name. Support for this feature can be
484 verified by using the "-list-features" command, which should
485 contain "data-disassemble-a-option".
487 ** Command responses and notifications that include a frame now include
488 the frame's architecture in a new "arch" attribute.
490 ** The output of information about multi-location breakpoints (which is
491 syntactically incorrect in MI 2) has changed in MI 3. This affects
492 the following commands and events:
496 - =breakpoint-created
497 - =breakpoint-modified
499 The -fix-multi-location-breakpoint-output command can be used to enable
500 this behavior with previous MI versions.
502 * New native configurations
504 GNU/Linux/RISC-V riscv*-*-linux*
505 FreeBSD/riscv riscv*-*-freebsd*
509 GNU/Linux/RISC-V riscv*-*-linux*
511 CSKY GNU/LINUX csky*-*-linux
512 FreeBSD/riscv riscv*-*-freebsd*
514 GNU/Linux/OpenRISC or1k*-*-linux*
518 GDB no longer supports native debugging on versions of MS-Windows
523 ** GDB no longer supports Python versions less than 2.6.
525 ** The gdb.Inferior type has a new 'progspace' property, which is the program
526 space associated to that inferior.
528 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
529 of objfiles associated to that program space.
531 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
532 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
535 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
536 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
537 correct and did not work properly.
539 ** The gdb.Value type has a new constructor, which is used to construct a
540 gdb.Value from a Python buffer object and a gdb.Type.
546 Enable or disable the undefined behavior sanitizer. This is
547 disabled by default, but passing --enable-ubsan=yes or
548 --enable-ubsan=auto to configure will enable it. Enabling this can
549 cause a performance penalty. The undefined behavior sanitizer was
550 first introduced in GCC 4.9.
552 *** Changes in GDB 8.2
554 * The 'set disassembler-options' command now supports specifying options
557 * The 'symbol-file' command now accepts an '-o' option to add a relative
558 offset to all sections.
560 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
561 a relative offset to all sections, but it allows to override the load
562 address of individual sections using '-s'.
564 * The 'add-symbol-file' command no longer requires the second argument
565 (address of the text section).
567 * The endianness used with the 'set endian auto' mode in the absence of
568 an executable selected for debugging is now the last endianness chosen
569 either by one of the 'set endian big' and 'set endian little' commands
570 or by inferring from the last executable used, rather than the startup
573 * The pager now allows a "c" response, meaning to disable the pager
574 for the rest of the current command.
576 * The commands 'info variables/functions/types' now show the source line
577 numbers of symbol definitions when available.
579 * 'info proc' now works on running processes on FreeBSD systems and core
580 files created on FreeBSD systems.
582 * C expressions can now use _Alignof, and C++ expressions can now use
585 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
586 the vector length while the process is running.
592 Control display of debugging info regarding the FreeBSD native target.
594 set|show varsize-limit
595 This new setting allows the user to control the maximum size of Ada
596 objects being printed when those objects have a variable type,
597 instead of that maximum size being hardcoded to 65536 bytes.
599 set|show record btrace cpu
600 Controls the processor to be used for enabling errata workarounds for
603 maint check libthread-db
604 Run integrity checks on the current inferior's thread debugging
607 maint set check-libthread-db (on|off)
608 maint show check-libthread-db
609 Control whether to run integrity checks on inferior specific thread
610 debugging libraries as they are loaded. The default is not to
615 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
617 ** The commands attached to a breakpoint can be set by assigning to
618 the breakpoint's "commands" field.
620 ** gdb.execute can now execute multi-line gdb commands.
622 ** The new functions gdb.convenience_variable and
623 gdb.set_convenience_variable can be used to get and set the value
624 of convenience variables.
626 ** A gdb.Parameter will no longer print the "set" help text on an
627 ordinary "set"; instead by default a "set" will be silent unless
628 the get_set_string method returns a non-empty string.
632 RiscV ELF riscv*-*-elf
634 * Removed targets and native configurations
636 m88k running OpenBSD m88*-*-openbsd*
637 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
638 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
639 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
641 * Aarch64/Linux hardware watchpoints improvements
643 Hardware watchpoints on unaligned addresses are now properly
644 supported when running Linux kernel 4.10 or higher: read and access
645 watchpoints are no longer spuriously missed, and all watchpoints
646 lengths between 1 and 8 bytes are supported. On older kernels,
647 watchpoints set on unaligned addresses are no longer missed, with
648 the tradeoff that there is a possibility of false hits being
653 --enable-codesign=CERT
654 This can be used to invoke "codesign -s CERT" after building gdb.
655 This option is useful on macOS, where code signing is required for
656 gdb to work properly.
658 --disable-gdbcli has been removed
659 This is now silently accepted, but does nothing.
661 *** Changes in GDB 8.1
663 * GDB now supports dynamically creating arbitrary register groups specified
664 in XML target descriptions. This allows for finer grain grouping of
665 registers on systems with a large amount of registers.
667 * The 'ptype' command now accepts a '/o' flag, which prints the
668 offsets and sizes of fields in a struct, like the pahole(1) tool.
670 * New "--readnever" command line option instructs GDB to not read each
671 symbol file's symbolic debug information. This makes startup faster
672 but at the expense of not being able to perform symbolic debugging.
673 This option is intended for use cases where symbolic debugging will
674 not be used, e.g., when you only need to dump the debuggee's core.
676 * GDB now uses the GNU MPFR library, if available, to emulate target
677 floating-point arithmetic during expression evaluation when the target
678 uses different floating-point formats than the host. At least version
679 3.1 of GNU MPFR is required.
681 * GDB now supports access to the guarded-storage-control registers and the
682 software-based guarded-storage broadcast control registers on IBM z14.
684 * On Unix systems, GDB now supports transmitting environment variables
685 that are to be set or unset to GDBserver. These variables will
686 affect the environment to be passed to the remote inferior.
688 To inform GDB of environment variables that are to be transmitted to
689 GDBserver, use the "set environment" command. Only user set
690 environment variables are sent to GDBserver.
692 To inform GDB of environment variables that are to be unset before
693 the remote inferior is started by the GDBserver, use the "unset
694 environment" command.
696 * Completion improvements
698 ** GDB can now complete function parameters in linespecs and
699 explicit locations without quoting. When setting breakpoints,
700 quoting around functions names to help with TAB-completion is
701 generally no longer necessary. For example, this now completes
704 (gdb) b function(in[TAB]
705 (gdb) b function(int)
707 Related, GDB is no longer confused with completing functions in
708 C++ anonymous namespaces:
711 (gdb) b (anonymous namespace)::[TAB][TAB]
712 (anonymous namespace)::a_function()
713 (anonymous namespace)::b_function()
715 ** GDB now has much improved linespec and explicit locations TAB
716 completion support, that better understands what you're
717 completing and offers better suggestions. For example, GDB no
718 longer offers data symbols as possible completions when you're
719 setting a breakpoint.
721 ** GDB now TAB-completes label symbol names.
723 ** The "complete" command now mimics TAB completion accurately.
725 * New command line options (gcore)
728 Dump all memory mappings.
730 * Breakpoints on C++ functions are now set on all scopes by default
732 By default, breakpoints on functions/methods are now interpreted as
733 specifying all functions with the given name ignoring missing
734 leading scopes (namespaces and classes).
736 For example, assuming a C++ program with symbols named:
741 both commands "break func()" and "break B::func()" set a breakpoint
744 You can use the new flag "-qualified" to override this. This makes
745 GDB interpret the specified function name as a complete
746 fully-qualified name instead. For example, using the same C++
747 program, the "break -q B::func" command sets a breakpoint on
748 "B::func", only. A parameter has been added to the Python
749 gdb.Breakpoint constructor to achieve the same result when creating
750 a breakpoint from Python.
752 * Breakpoints on functions marked with C++ ABI tags
754 GDB can now set breakpoints on functions marked with C++ ABI tags
755 (e.g., [abi:cxx11]). See here for a description of ABI tags:
756 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
758 Functions with a C++11 abi tag are demangled/displayed like this:
760 function[abi:cxx11](int)
763 You can now set a breakpoint on such functions simply as if they had
766 (gdb) b function(int)
768 Or if you need to disambiguate between tags, like:
770 (gdb) b function[abi:other_tag](int)
772 Tab completion was adjusted accordingly as well.
776 ** New events gdb.new_inferior, gdb.inferior_deleted, and
777 gdb.new_thread are emitted. See the manual for further
778 description of these.
780 ** A new function, "gdb.rbreak" has been added to the Python API.
781 This function allows the setting of a large number of breakpoints
782 via a regex pattern in Python. See the manual for further details.
784 ** Python breakpoints can now accept explicit locations. See the
785 manual for a further description of this feature.
788 * New features in the GDB remote stub, GDBserver
790 ** GDBserver is now able to start inferior processes with a
791 specified initial working directory.
793 The user can set the desired working directory to be used from
794 GDB using the new "set cwd" command.
796 ** New "--selftest" command line option runs some GDBserver self
797 tests. These self tests are disabled in releases.
799 ** On Unix systems, GDBserver now does globbing expansion and variable
800 substitution in inferior command line arguments.
802 This is done by starting inferiors using a shell, like GDB does.
803 See "set startup-with-shell" in the user manual for how to disable
804 this from GDB when using "target extended-remote". When using
805 "target remote", you can disable the startup with shell by using the
806 new "--no-startup-with-shell" GDBserver command line option.
808 ** On Unix systems, GDBserver now supports receiving environment
809 variables that are to be set or unset from GDB. These variables
810 will affect the environment to be passed to the inferior.
812 * When catching an Ada exception raised with a message, GDB now prints
813 the message in the catchpoint hit notification. In GDB/MI mode, that
814 information is provided as an extra field named "exception-message"
815 in the *stopped notification.
817 * Trait objects can now be inspected When debugging Rust code. This
818 requires compiler support which will appear in Rust 1.24.
822 QEnvironmentHexEncoded
823 Inform GDBserver of an environment variable that is to be passed to
824 the inferior when starting it.
827 Inform GDBserver of an environment variable that is to be unset
828 before starting the remote inferior.
831 Inform GDBserver that the environment should be reset (i.e.,
832 user-set environment variables should be unset).
835 Indicates whether the inferior must be started with a shell or not.
838 Tell GDBserver that the inferior to be started should use a specific
841 * The "maintenance print c-tdesc" command now takes an optional
842 argument which is the file name of XML target description.
844 * The "maintenance selftest" command now takes an optional argument to
845 filter the tests to be run.
847 * The "enable", and "disable" commands now accept a range of
848 breakpoint locations, e.g. "enable 1.3-5".
853 Set and show the current working directory for the inferior.
856 Set and show compilation command used for compiling and injecting code
857 with the 'compile' commands.
859 set debug separate-debug-file
860 show debug separate-debug-file
861 Control the display of debug output about separate debug file search.
863 set dump-excluded-mappings
864 show dump-excluded-mappings
865 Control whether mappings marked with the VM_DONTDUMP flag should be
866 dumped when generating a core file.
869 List the registered selftests.
872 Start the debugged program stopping at the first instruction.
875 Control display of debugging messages related to OpenRISC targets.
877 set|show print type nested-type-limit
878 Set and show the limit of nesting level for nested types that the
879 type printer will show.
881 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
884 * Safer/improved support for debugging with no debug info
886 GDB no longer assumes functions with no debug information return
889 This means that GDB now refuses to call such functions unless you
890 tell it the function's type, by either casting the call to the
891 declared return type, or by casting the function to a function
892 pointer of the right type, and calling that:
894 (gdb) p getenv ("PATH")
895 'getenv' has unknown return type; cast the call to its declared return type
896 (gdb) p (char *) getenv ("PATH")
897 $1 = 0x7fffffffe "/usr/local/bin:/"...
898 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
899 $2 = 0x7fffffffe "/usr/local/bin:/"...
901 Similarly, GDB no longer assumes that global variables with no debug
902 info have type 'int', and refuses to print the variable's value
903 unless you tell it the variable's type:
906 'var' has unknown type; cast it to its declared type
910 * New native configurations
912 FreeBSD/aarch64 aarch64*-*-freebsd*
913 FreeBSD/arm arm*-*-freebsd*
917 FreeBSD/aarch64 aarch64*-*-freebsd*
918 FreeBSD/arm arm*-*-freebsd*
919 OpenRISC ELF or1k*-*-elf
921 * Removed targets and native configurations
923 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
925 *** Changes in GDB 8.0
927 * GDB now supports access to the PKU register on GNU/Linux. The register is
928 added by the Memory Protection Keys for Userspace feature which will be
929 available in future Intel CPUs.
931 * GDB now supports C++11 rvalue references.
935 ** New functions to start, stop and access a running btrace recording.
936 ** Rvalue references are now supported in gdb.Type.
938 * GDB now supports recording and replaying rdrand and rdseed Intel 64
941 * Building GDB and GDBserver now requires a C++11 compiler.
943 For example, GCC 4.8 or later.
945 It is no longer possible to build GDB or GDBserver with a C
946 compiler. The --disable-build-with-cxx configure option has been
949 * Building GDB and GDBserver now requires GNU make >= 3.81.
951 It is no longer supported to build GDB or GDBserver with another
952 implementation of the make program or an earlier version of GNU make.
954 * Native debugging on MS-Windows supports command-line redirection
956 Command-line arguments used for starting programs on MS-Windows can
957 now include redirection symbols supported by native Windows shells,
958 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
959 as "run", "start", and "set args", as well as the corresponding MI
962 * Support for thread names on MS-Windows.
964 GDB now catches and handles the special exception that programs
965 running on MS-Windows use to assign names to threads in the
968 * Support for Java programs compiled with gcj has been removed.
970 * User commands now accept an unlimited number of arguments.
971 Previously, only up to 10 was accepted.
973 * The "eval" command now expands user-defined command arguments.
975 This makes it easier to process a variable number of arguments:
980 eval "print $arg%d", $i
985 * Target descriptions can now describe registers for sparc32 and sparc64.
987 * GDB now supports DWARF version 5 (debug information format).
988 Its .debug_names index is not yet supported.
990 * New native configurations
992 FreeBSD/mips mips*-*-freebsd
996 Synopsys ARC arc*-*-elf32
997 FreeBSD/mips mips*-*-freebsd
999 * Removed targets and native configurations
1001 Alpha running FreeBSD alpha*-*-freebsd*
1002 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1007 Erases all the flash memory regions reported by the target.
1009 maint print arc arc-instruction address
1010 Print internal disassembler information about instruction at a given address.
1014 set disassembler-options
1015 show disassembler-options
1016 Controls the passing of target specific information to the disassembler.
1017 If it is necessary to specify more than one disassembler option then
1018 multiple options can be placed together into a comma separated list.
1019 The default value is the empty string. Currently, the only supported
1020 targets are ARM, PowerPC and S/390.
1025 Erases all the flash memory regions reported by the target. This is
1026 equivalent to the CLI command flash-erase.
1028 -file-list-shared-libraries
1029 List the shared libraries in the program. This is
1030 equivalent to the CLI command "info shared".
1033 Catchpoints stopping the program when Ada exceptions are
1034 handled. This is equivalent to the CLI command "catch handlers".
1036 *** Changes in GDB 7.12
1038 * GDB and GDBserver now build with a C++ compiler by default.
1040 The --enable-build-with-cxx configure option is now enabled by
1041 default. One must now explicitly configure with
1042 --disable-build-with-cxx in order to build with a C compiler. This
1043 option will be removed in a future release.
1045 * GDBserver now supports recording btrace without maintaining an active
1048 * GDB now supports a negative repeat count in the 'x' command to examine
1049 memory backward from the given address. For example:
1052 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1053 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1054 (gdb) x/-5i 0x0000000000400580
1055 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1056 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1057 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1058 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1059 0x40057b <main(int, char**)+25>:
1060 callq 0x400536 <Func1(int, char const*)>
1062 * Fortran: Support structures with fields of dynamic types and
1063 arrays of dynamic types.
1065 * The symbol dumping maintenance commands have new syntax.
1066 maint print symbols [-pc address] [--] [filename]
1067 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1068 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1069 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1070 maint print msymbols [-objfile objfile] [--] [filename]
1072 * GDB now supports multibit bitfields and enums in target register
1075 * New Python-based convenience function $_as_string(val), which returns
1076 the textual representation of a value. This function is especially
1077 useful to obtain the text label of an enum value.
1079 * Intel MPX bound violation handling.
1081 Segmentation faults caused by a Intel MPX boundary violation
1082 now display the kind of violation (upper or lower), the memory
1083 address accessed and the memory bounds, along with the usual
1084 signal received and code location.
1088 Program received signal SIGSEGV, Segmentation fault
1089 Upper bound violation while accessing address 0x7fffffffc3b3
1090 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1091 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1093 * Rust language support.
1094 GDB now supports debugging programs written in the Rust programming
1095 language. See https://www.rust-lang.org/ for more information about
1098 * Support for running interpreters on specified input/output devices
1100 GDB now supports a new mechanism that allows frontends to provide
1101 fully featured GDB console views, as a better alternative to
1102 building such views on top of the "-interpreter-exec console"
1103 command. See the new "new-ui" command below. With that command,
1104 frontends can now start GDB in the traditional command-line mode
1105 running in an embedded terminal emulator widget, and create a
1106 separate MI interpreter running on a specified i/o device. In this
1107 way, GDB handles line editing, history, tab completion, etc. in the
1108 console all by itself, and the GUI uses the separate MI interpreter
1109 for its own control and synchronization, invisible to the command
1112 * The "catch syscall" command catches groups of related syscalls.
1114 The "catch syscall" command now supports catching a group of related
1115 syscalls using the 'group:' or 'g:' prefix.
1120 skip -gfile file-glob-pattern
1121 skip -function function
1122 skip -rfunction regular-expression
1123 A generalized form of the skip command, with new support for
1124 glob-style file names and regular expressions for function names.
1125 Additionally, a file spec and a function spec may now be combined.
1127 maint info line-table REGEXP
1128 Display the contents of GDB's internal line table data struture.
1131 Run any GDB unit tests that were compiled in.
1134 Start a new user interface instance running INTERP as interpreter,
1135 using the TTY file for input/output.
1139 ** gdb.Breakpoint objects have a new attribute "pending", which
1140 indicates whether the breakpoint is pending.
1141 ** Three new breakpoint-related events have been added:
1142 gdb.breakpoint_created, gdb.breakpoint_modified, and
1143 gdb.breakpoint_deleted.
1145 signal-event EVENTID
1146 Signal ("set") the given MS-Windows event object. This is used in
1147 conjunction with the Windows JIT debugging (AeDebug) support, where
1148 the OS suspends a crashing process until a debugger can attach to
1149 it. Resuming the crashing process, in order to debug it, is done by
1150 signalling an event.
1152 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1153 was added in GDBserver, including JIT compiling fast tracepoint's
1154 conditional expression bytecode into native code.
1156 * Support for various remote target protocols and ROM monitors has
1159 target m32rsdi Remote M32R debugging over SDI
1160 target mips MIPS remote debugging protocol
1161 target pmon PMON ROM monitor
1162 target ddb NEC's DDB variant of PMON for Vr4300
1163 target rockhopper NEC RockHopper variant of PMON
1164 target lsi LSI variant of PMO
1166 * Support for tracepoints and fast tracepoints on powerpc-linux,
1167 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1168 including JIT compiling fast tracepoint's conditional expression
1169 bytecode into native code.
1171 * MI async record =record-started now includes the method and format used for
1172 recording. For example:
1174 =record-started,thread-group="i1",method="btrace",format="bts"
1176 * MI async record =thread-selected now includes the frame field. For example:
1178 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1182 Andes NDS32 nds32*-*-elf
1184 *** Changes in GDB 7.11
1186 * GDB now supports debugging kernel-based threads on FreeBSD.
1188 * Per-inferior thread numbers
1190 Thread numbers are now per inferior instead of global. If you're
1191 debugging multiple inferiors, GDB displays thread IDs using a
1192 qualified INF_NUM.THR_NUM form. For example:
1196 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1197 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1198 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1199 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1201 As consequence, thread numbers as visible in the $_thread
1202 convenience variable and in Python's InferiorThread.num attribute
1203 are no longer unique between inferiors.
1205 GDB now maintains a second thread ID per thread, referred to as the
1206 global thread ID, which is the new equivalent of thread numbers in
1207 previous releases. See also $_gthread below.
1209 For backwards compatibility, MI's thread IDs always refer to global
1212 * Commands that accept thread IDs now accept the qualified
1213 INF_NUM.THR_NUM form as well. For example:
1216 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1219 * In commands that accept a list of thread IDs, you can now refer to
1220 all threads of an inferior using a star wildcard. GDB accepts
1221 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1222 refer to all threads of the current inferior. For example, "info
1225 * You can use "info threads -gid" to display the global thread ID of
1228 * The new convenience variable $_gthread holds the global number of
1231 * The new convenience variable $_inferior holds the number of the
1234 * GDB now displays the ID and name of the thread that hit a breakpoint
1235 or received a signal, if your program is multi-threaded. For
1238 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1239 Thread 1 "main" received signal SIGINT, Interrupt.
1241 * Record btrace now supports non-stop mode.
1243 * Support for tracepoints on aarch64-linux was added in GDBserver.
1245 * The 'record instruction-history' command now indicates speculative execution
1246 when using the Intel Processor Trace recording format.
1248 * GDB now allows users to specify explicit locations, bypassing
1249 the linespec parser. This feature is also available to GDB/MI
1252 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1253 GDB now is able to debug both AArch64 applications and ARM applications
1256 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1257 including JIT compiling fast tracepoint's conditional expression bytecode
1260 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1262 * "info threads", "info inferiors", "info display", "info checkpoints"
1263 and "maint info program-spaces" now list the corresponding items in
1264 ascending ID order, for consistency with all other "info" commands.
1266 * In Ada, the overloads selection menu has been enhanced to display the
1267 parameter types and the return types for the matching overloaded subprograms.
1271 maint set target-non-stop (on|off|auto)
1272 maint show target-non-stop
1273 Control whether GDB targets always operate in non-stop mode even if
1274 "set non-stop" is "off". The default is "auto", meaning non-stop
1275 mode is enabled if supported by the target.
1277 maint set bfd-sharing
1278 maint show bfd-sharing
1279 Control the reuse of bfd objects.
1282 show debug bfd-cache
1283 Control display of debugging info regarding bfd caching.
1287 Control display of debugging info regarding FreeBSD threads.
1289 set remote multiprocess-extensions-packet
1290 show remote multiprocess-extensions-packet
1291 Set/show the use of the remote protocol multiprocess extensions.
1293 set remote thread-events
1294 show remote thread-events
1295 Set/show the use of thread create/exit events.
1297 set ada print-signatures on|off
1298 show ada print-signatures"
1299 Control whether parameter types and return types are displayed in overloads
1300 selection menus. It is activaled (@code{on}) by default.
1304 Controls the maximum size of memory, in bytes, that GDB will
1305 allocate for value contents. Prevents incorrect programs from
1306 causing GDB to allocate overly large buffers. Default is 64k.
1308 * The "disassemble" command accepts a new modifier: /s.
1309 It prints mixed source+disassembly like /m with two differences:
1310 - disassembled instructions are now printed in program order, and
1311 - and source for all relevant files is now printed.
1312 The "/m" option is now considered deprecated: its "source-centric"
1313 output hasn't proved useful in practice.
1315 * The "record instruction-history" command accepts a new modifier: /s.
1316 It behaves exactly like /m and prints mixed source+disassembly.
1318 * The "set scheduler-locking" command supports a new mode "replay".
1319 It behaves like "off" in record mode and like "on" in replay mode.
1321 * Support for various ROM monitors has been removed:
1323 target dbug dBUG ROM monitor for Motorola ColdFire
1324 target picobug Motorola picobug monitor
1325 target dink32 DINK32 ROM monitor for PowerPC
1326 target m32r Renesas M32R/D ROM monitor
1327 target mon2000 mon2000 ROM monitor
1328 target ppcbug PPCBUG ROM monitor for PowerPC
1330 * Support for reading/writing memory and extracting values on architectures
1331 whose memory is addressable in units of any integral multiple of 8 bits.
1334 Allows to break when an Ada exception is handled.
1336 * New remote packets
1339 Indicates that an exec system call was executed.
1341 exec-events feature in qSupported
1342 The qSupported packet allows GDB to request support for exec
1343 events using the new 'gdbfeature' exec-event, and the qSupported
1344 response can contain the corresponding 'stubfeature'. Set and
1345 show commands can be used to display whether these features are enabled.
1348 Equivalent to interrupting with the ^C character, but works in
1351 thread created stop reason (T05 create:...)
1352 Indicates that the thread was just created and is stopped at entry.
1354 thread exit stop reply (w exitcode;tid)
1355 Indicates that the thread has terminated.
1358 Enables/disables thread create and exit event reporting. For
1359 example, this is used in non-stop mode when GDB stops a set of
1360 threads and synchronously waits for the their corresponding stop
1361 replies. Without exit events, if one of the threads exits, GDB
1362 would hang forever not knowing that it should no longer expect a
1363 stop for that same thread.
1366 Indicates that there are no resumed threads left in the target (all
1367 threads are stopped). The remote stub reports support for this stop
1368 reply to GDB's qSupported query.
1371 Enables/disables catching syscalls from the inferior process.
1372 The remote stub reports support for this packet to GDB's qSupported query.
1374 syscall_entry stop reason
1375 Indicates that a syscall was just called.
1377 syscall_return stop reason
1378 Indicates that a syscall just returned.
1380 * Extended-remote exec events
1382 ** GDB now has support for exec events on extended-remote Linux targets.
1383 For such targets with Linux kernels 2.5.46 and later, this enables
1384 follow-exec-mode and exec catchpoints.
1386 set remote exec-event-feature-packet
1387 show remote exec-event-feature-packet
1388 Set/show the use of the remote exec event feature.
1390 * Thread names in remote protocol
1392 The reply to qXfer:threads:read may now include a name attribute for each
1395 * Target remote mode fork and exec events
1397 ** GDB now has support for fork and exec events on target remote mode
1398 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1399 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1400 fork and exec catchpoints.
1402 * Remote syscall events
1404 ** GDB now has support for catch syscall on remote Linux targets,
1405 currently enabled on x86/x86_64 architectures.
1407 set remote catch-syscall-packet
1408 show remote catch-syscall-packet
1409 Set/show the use of the remote catch syscall feature.
1413 ** The -var-set-format command now accepts the zero-hexadecimal
1414 format. It outputs data in hexadecimal format with zero-padding on the
1419 ** gdb.InferiorThread objects have a new attribute "global_num",
1420 which refers to the thread's global thread ID. The existing
1421 "num" attribute now refers to the thread's per-inferior number.
1422 See "Per-inferior thread numbers" above.
1423 ** gdb.InferiorThread objects have a new attribute "inferior", which
1424 is the Inferior object the thread belongs to.
1426 *** Changes in GDB 7.10
1428 * Support for process record-replay and reverse debugging on aarch64*-linux*
1429 targets has been added. GDB now supports recording of A64 instruction set
1430 including advance SIMD instructions.
1432 * Support for Sun's version of the "stabs" debug file format has been removed.
1434 * GDB now honors the content of the file /proc/PID/coredump_filter
1435 (PID is the process ID) on GNU/Linux systems. This file can be used
1436 to specify the types of memory mappings that will be included in a
1437 corefile. For more information, please refer to the manual page of
1438 "core(5)". GDB also has a new command: "set use-coredump-filter
1439 on|off". It allows to set whether GDB will read the content of the
1440 /proc/PID/coredump_filter file when generating a corefile.
1442 * The "info os" command on GNU/Linux can now display information on
1444 "info os cpus" Listing of all cpus/cores on the system
1446 * GDB has two new commands: "set serial parity odd|even|none" and
1447 "show serial parity". These allows to set or show parity for the
1450 * The "info source" command now displays the producer string if it was
1451 present in the debug info. This typically includes the compiler version
1452 and may include things like its command line arguments.
1454 * The "info dll", an alias of the "info sharedlibrary" command,
1455 is now available on all platforms.
1457 * Directory names supplied to the "set sysroot" commands may be
1458 prefixed with "target:" to tell GDB to access shared libraries from
1459 the target system, be it local or remote. This replaces the prefix
1460 "remote:". The default sysroot has been changed from "" to
1461 "target:". "remote:" is automatically converted to "target:" for
1462 backward compatibility.
1464 * The system root specified by "set sysroot" will be prepended to the
1465 filename of the main executable (if reported to GDB as absolute by
1466 the operating system) when starting processes remotely, and when
1467 attaching to already-running local or remote processes.
1469 * GDB now supports automatic location and retrieval of executable
1470 files from remote targets. Remote debugging can now be initiated
1471 using only a "target remote" or "target extended-remote" command
1472 (no "set sysroot" or "file" commands are required). See "New remote
1475 * The "dump" command now supports verilog hex format.
1477 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1479 * On GNU/Linux, GDB and gdbserver are now able to access executable
1480 and shared library files without a "set sysroot" command when
1481 attaching to processes running in different mount namespaces from
1482 the debugger. This makes it possible to attach to processes in
1483 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1484 See "New remote packets" below.
1486 * The "tui reg" command now provides completion for all of the
1487 available register groups, including target specific groups.
1489 * The HISTSIZE environment variable is no longer read when determining
1490 the size of GDB's command history. GDB now instead reads the dedicated
1491 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1492 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1497 ** Memory ports can now be unbuffered.
1501 ** gdb.Objfile objects have a new attribute "username",
1502 which is the name of the objfile as specified by the user,
1503 without, for example, resolving symlinks.
1504 ** You can now write frame unwinders in Python.
1505 ** gdb.Type objects have a new method "optimized_out",
1506 returning optimized out gdb.Value instance of this type.
1507 ** gdb.Value objects have new methods "reference_value" and
1508 "const_value" which return a reference to the value and a
1509 "const" version of the value respectively.
1513 maint print symbol-cache
1514 Print the contents of the symbol cache.
1516 maint print symbol-cache-statistics
1517 Print statistics of symbol cache usage.
1519 maint flush-symbol-cache
1520 Flush the contents of the symbol cache.
1524 Start branch trace recording using Branch Trace Store (BTS) format.
1527 Evaluate expression by using the compiler and print result.
1531 Explicit commands for enabling and disabling tui mode.
1534 set mpx bound on i386 and amd64
1535 Support for bound table investigation on Intel MPX enabled applications.
1539 Start branch trace recording using Intel Processor Trace format.
1542 Print information about branch tracing internals.
1544 maint btrace packet-history
1545 Print the raw branch tracing data.
1547 maint btrace clear-packet-history
1548 Discard the stored raw branch tracing data.
1551 Discard all branch tracing data. It will be fetched and processed
1552 anew by the next "record" command.
1557 Renamed from "set debug dwarf2-die".
1558 show debug dwarf-die
1559 Renamed from "show debug dwarf2-die".
1561 set debug dwarf-read
1562 Renamed from "set debug dwarf2-read".
1563 show debug dwarf-read
1564 Renamed from "show debug dwarf2-read".
1566 maint set dwarf always-disassemble
1567 Renamed from "maint set dwarf2 always-disassemble".
1568 maint show dwarf always-disassemble
1569 Renamed from "maint show dwarf2 always-disassemble".
1571 maint set dwarf max-cache-age
1572 Renamed from "maint set dwarf2 max-cache-age".
1573 maint show dwarf max-cache-age
1574 Renamed from "maint show dwarf2 max-cache-age".
1576 set debug dwarf-line
1577 show debug dwarf-line
1578 Control display of debugging info regarding DWARF line processing.
1581 show max-completions
1582 Set the maximum number of candidates to be considered during
1583 completion. The default value is 200. This limit allows GDB
1584 to avoid generating large completion lists, the computation of
1585 which can cause the debugger to become temporarily unresponsive.
1587 set history remove-duplicates
1588 show history remove-duplicates
1589 Control the removal of duplicate history entries.
1591 maint set symbol-cache-size
1592 maint show symbol-cache-size
1593 Control the size of the symbol cache.
1595 set|show record btrace bts buffer-size
1596 Set and show the size of the ring buffer used for branch tracing in
1598 The obtained size may differ from the requested size. Use "info
1599 record" to see the obtained buffer size.
1601 set debug linux-namespaces
1602 show debug linux-namespaces
1603 Control display of debugging info regarding Linux namespaces.
1605 set|show record btrace pt buffer-size
1606 Set and show the size of the ring buffer used for branch tracing in
1607 Intel Processor Trace format.
1608 The obtained size may differ from the requested size. Use "info
1609 record" to see the obtained buffer size.
1611 maint set|show btrace pt skip-pad
1612 Set and show whether PAD packets are skipped when computing the
1615 * The command 'thread apply all' can now support new option '-ascending'
1616 to call its specified command for all threads in ascending order.
1618 * Python/Guile scripting
1620 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1621 special section named `.debug_gdb_scripts'.
1623 * New remote packets
1625 qXfer:btrace-conf:read
1626 Return the branch trace configuration for the current thread.
1628 Qbtrace-conf:bts:size
1629 Set the requested ring buffer size for branch tracing in BTS format.
1632 Enable Intel Procesor Trace-based branch tracing for the current
1633 process. The remote stub reports support for this packet to GDB's
1636 Qbtrace-conf:pt:size
1637 Set the requested ring buffer size for branch tracing in Intel Processor
1641 Indicates a memory breakpoint instruction was executed, irrespective
1642 of whether it was GDB that planted the breakpoint or the breakpoint
1643 is hardcoded in the program. This is required for correct non-stop
1647 Indicates the target stopped for a hardware breakpoint. This is
1648 required for correct non-stop mode operation.
1651 Return information about files on the remote system.
1653 qXfer:exec-file:read
1654 Return the full absolute name of the file that was executed to
1655 create a process running on the remote system.
1658 Select the filesystem on which vFile: operations with filename
1659 arguments will operate. This is required for GDB to be able to
1660 access files on remote targets where the remote stub does not
1661 share a common filesystem with the inferior(s).
1664 Indicates that a fork system call was executed.
1667 Indicates that a vfork system call was executed.
1669 vforkdone stop reason
1670 Indicates that a vfork child of the specified process has executed
1671 an exec or exit, allowing the vfork parent to resume execution.
1673 fork-events and vfork-events features in qSupported
1674 The qSupported packet allows GDB to request support for fork and
1675 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1676 and the qSupported response can contain the corresponding
1677 'stubfeatures'. Set and show commands can be used to display
1678 whether these features are enabled.
1680 * Extended-remote fork events
1682 ** GDB now has support for fork events on extended-remote Linux
1683 targets. For targets with Linux kernels 2.5.60 and later, this
1684 enables follow-fork-mode and detach-on-fork for both fork and
1685 vfork, as well as fork and vfork catchpoints.
1687 * The info record command now shows the recording format and the
1688 branch tracing configuration for the current thread when using
1689 the btrace record target.
1690 For the BTS format, it shows the ring buffer size.
1692 * GDB now has support for DTrace USDT (Userland Static Defined
1693 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1695 * GDB now supports access to vector registers on S/390 GNU/Linux
1698 * Removed command line options
1700 -xdb HP-UX XDB compatibility mode.
1702 * Removed targets and native configurations
1704 HP/PA running HP-UX hppa*-*-hpux*
1705 Itanium running HP-UX ia64-*-hpux*
1707 * New configure options
1710 This configure option allows the user to build GDB with support for
1711 Intel Processor Trace (default: auto). This requires libipt.
1713 --with-libipt-prefix=PATH
1714 Specify the path to the version of libipt that GDB should use.
1715 $PATH/include should contain the intel-pt.h header and
1716 $PATH/lib should contain the libipt.so library.
1718 *** Changes in GDB 7.9.1
1722 ** Xmethods can now specify a result type.
1724 *** Changes in GDB 7.9
1726 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1730 ** You can now access frame registers from Python scripts.
1731 ** New attribute 'producer' for gdb.Symtab objects.
1732 ** gdb.Objfile objects have a new attribute "progspace",
1733 which is the gdb.Progspace object of the containing program space.
1734 ** gdb.Objfile objects have a new attribute "owner".
1735 ** gdb.Objfile objects have a new attribute "build_id",
1736 which is the build ID generated when the file was built.
1737 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1738 ** A new event "gdb.clear_objfiles" has been added, triggered when
1739 selecting a new file to debug.
1740 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1741 ** New function gdb.lookup_objfile.
1743 New events which are triggered when GDB modifies the state of the
1746 ** gdb.events.inferior_call_pre: Function call is about to be made.
1747 ** gdb.events.inferior_call_post: Function call has just been made.
1748 ** gdb.events.memory_changed: A memory location has been altered.
1749 ** gdb.events.register_changed: A register has been altered.
1751 * New Python-based convenience functions:
1753 ** $_caller_is(name [, number_of_frames])
1754 ** $_caller_matches(regexp [, number_of_frames])
1755 ** $_any_caller_is(name [, number_of_frames])
1756 ** $_any_caller_matches(regexp [, number_of_frames])
1758 * GDB now supports the compilation and injection of source code into
1759 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1760 to compile the source code to object code, and if successful, inject
1761 and execute that code within the current context of the inferior.
1762 Currently the C language is supported. The commands used to
1763 interface with this new feature are:
1765 compile code [-raw|-r] [--] [source code]
1766 compile file [-raw|-r] filename
1770 demangle [-l language] [--] name
1771 Demangle "name" in the specified language, or the current language
1772 if elided. This command is renamed from the "maint demangle" command.
1773 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1774 as "maint demangler-warning".
1776 queue-signal signal-name-or-number
1777 Queue a signal to be delivered to the thread when it is resumed.
1779 add-auto-load-scripts-directory directory
1780 Add entries to the list of directories from which to load auto-loaded
1783 maint print user-registers
1784 List all currently available "user" registers.
1786 compile code [-r|-raw] [--] [source code]
1787 Compile, inject, and execute in the inferior the executable object
1788 code produced by compiling the provided source code.
1790 compile file [-r|-raw] filename
1791 Compile and inject into the inferior the executable object code
1792 produced by compiling the source code stored in the filename
1795 * On resume, GDB now always passes the signal the program had stopped
1796 for to the thread the signal was sent to, even if the user changed
1797 threads before resuming. Previously GDB would often (but not
1798 always) deliver the signal to the thread that happens to be current
1801 * Conversely, the "signal" command now consistently delivers the
1802 requested signal to the current thread. GDB now asks for
1803 confirmation if the program had stopped for a signal and the user
1804 switched threads meanwhile.
1806 * "breakpoint always-inserted" modes "off" and "auto" merged.
1808 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1809 won't remove breakpoints from the target until all threads stop,
1810 even in non-stop mode. The "auto" mode has been removed, and "off"
1811 is now the default mode.
1815 set debug symbol-lookup
1816 show debug symbol-lookup
1817 Control display of debugging info regarding symbol lookup.
1821 ** The -list-thread-groups command outputs an exit-code field for
1822 inferiors that have exited.
1826 MIPS SDE mips*-sde*-elf*
1830 Support for these obsolete configurations has been removed.
1832 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1833 SGI Irix-5.x mips-*-irix5*
1834 SGI Irix-6.x mips-*-irix6*
1835 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1836 VAX running Ultrix vax-*-ultrix*
1838 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1839 and "assf"), have been removed. Use the "sharedlibrary" command, or
1840 its alias "share", instead.
1842 *** Changes in GDB 7.8
1844 * New command line options
1847 This is an alias for the --data-directory option.
1849 * GDB supports printing and modifying of variable length automatic arrays
1850 as specified in ISO C99.
1852 * The ARM simulator now supports instruction level tracing
1853 with or without disassembly.
1857 GDB now has support for scripting using Guile. Whether this is
1858 available is determined at configure time.
1859 Guile version 2.0 or greater is required.
1860 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1862 * New commands (for set/show, see "New options" below)
1866 Invoke CODE by passing it to the Guile interpreter.
1870 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1872 info auto-load guile-scripts [regexp]
1873 Print the list of automatically loaded Guile scripts.
1875 * The source command is now capable of sourcing Guile scripts.
1876 This feature is dependent on the debugger being built with Guile support.
1880 set print symbol-loading (off|brief|full)
1881 show print symbol-loading
1882 Control whether to print informational messages when loading symbol
1883 information for a file. The default is "full", but when debugging
1884 programs with large numbers of shared libraries the amount of output
1885 becomes less useful.
1887 set guile print-stack (none|message|full)
1888 show guile print-stack
1889 Show a stack trace when an error is encountered in a Guile script.
1891 set auto-load guile-scripts (on|off)
1892 show auto-load guile-scripts
1893 Control auto-loading of Guile script files.
1895 maint ada set ignore-descriptive-types (on|off)
1896 maint ada show ignore-descriptive-types
1897 Control whether the debugger should ignore descriptive types in Ada
1898 programs. The default is not to ignore the descriptive types. See
1899 the user manual for more details on descriptive types and the intended
1900 usage of this option.
1902 set auto-connect-native-target
1904 Control whether GDB is allowed to automatically connect to the
1905 native target for the run, attach, etc. commands when not connected
1906 to any target yet. See also "target native" below.
1908 set record btrace replay-memory-access (read-only|read-write)
1909 show record btrace replay-memory-access
1910 Control what memory accesses are allowed during replay.
1912 maint set target-async (on|off)
1913 maint show target-async
1914 This controls whether GDB targets operate in synchronous or
1915 asynchronous mode. Normally the default is asynchronous, if it is
1916 available; but this can be changed to more easily debug problems
1917 occurring only in synchronous mode.
1919 set mi-async (on|off)
1921 Control whether MI asynchronous mode is preferred. This supersedes
1922 "set target-async" of previous GDB versions.
1924 * "set target-async" is deprecated as a CLI option and is now an alias
1925 for "set mi-async" (only puts MI into async mode).
1927 * Background execution commands (e.g., "c&", "s&", etc.) are now
1928 possible ``out of the box'' if the target supports them. Previously
1929 the user would need to explicitly enable the possibility with the
1930 "set target-async on" command.
1932 * New features in the GDB remote stub, GDBserver
1934 ** New option --debug-format=option1[,option2,...] allows one to add
1935 additional text to each output. At present only timestamps
1936 are supported: --debug-format=timestamps.
1937 Timestamps can also be turned on with the
1938 "monitor set debug-format timestamps" command from GDB.
1940 * The 'record instruction-history' command now starts counting instructions
1941 at one. This also affects the instruction ranges reported by the
1942 'record function-call-history' command when given the /i modifier.
1944 * The command 'record function-call-history' supports a new modifier '/c' to
1945 indent the function names based on their call stack depth.
1946 The fields for the '/i' and '/l' modifier have been reordered.
1947 The source line range is now prefixed with 'at'.
1948 The instruction range is now prefixed with 'inst'.
1949 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1950 "record instruction-history" and "list" commands.
1952 * The ranges given as arguments to the 'record function-call-history' and
1953 'record instruction-history' commands are now inclusive.
1955 * The btrace record target now supports the 'record goto' command.
1956 For locations inside the execution trace, the back trace is computed
1957 based on the information stored in the execution trace.
1959 * The btrace record target supports limited reverse execution and replay.
1960 The target does not record data and therefore does not allow reading
1961 memory or registers.
1963 * The "catch syscall" command now works on s390*-linux* targets.
1965 * The "compare-sections" command is no longer specific to target
1966 remote. It now works with all targets.
1968 * All native targets are now consistently called "native".
1969 Consequently, the "target child", "target GNU", "target djgpp",
1970 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1971 commands have been replaced with "target native". The QNX/NTO port
1972 leaves the "procfs" target in place and adds a "native" target for
1973 consistency with other ports. The impact on users should be minimal
1974 as these commands previously either throwed an error, or were
1975 no-ops. The target's name is visible in the output of the following
1976 commands: "help target", "info target", "info files", "maint print
1979 * The "target native" command now connects to the native target. This
1980 can be used to launch native programs even when "set
1981 auto-connect-native-target" is set to off.
1983 * GDB now supports access to Intel MPX registers on GNU/Linux.
1985 * Support for Intel AVX-512 registers on GNU/Linux.
1986 Support displaying and modifying Intel AVX-512 registers
1987 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1989 * New remote packets
1991 qXfer:btrace:read's annex
1992 The qXfer:btrace:read packet supports a new annex 'delta' to read
1993 branch trace incrementally.
1997 ** Valid Python operations on gdb.Value objects representing
1998 structs/classes invoke the corresponding overloaded operators if
2000 ** New `Xmethods' feature in the Python API. Xmethods are
2001 additional methods or replacements for existing methods of a C++
2002 class. This feature is useful for those cases where a method
2003 defined in C++ source code could be inlined or optimized out by
2004 the compiler, making it unavailable to GDB.
2007 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2009 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2010 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2011 its alias "share", instead.
2013 * The commands "set remotebaud" and "show remotebaud" are no longer
2014 supported. Use "set serial baud" and "show serial baud" (respectively)
2019 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2020 target-async". The latter is left as a deprecated alias of the
2021 former for backward compatibility. If the target supports it,
2022 CLI background execution commands are now always possible by
2023 default, independently of whether the frontend stated a
2024 preference for asynchronous execution with "-gdb-set mi-async".
2025 Previously "-gdb-set target-async off" affected both MI execution
2026 commands and CLI execution commands.
2028 *** Changes in GDB 7.7
2030 * Improved support for process record-replay and reverse debugging on
2031 arm*-linux* targets. Support for thumb32 and syscall instruction
2032 recording has been added.
2034 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2036 * GDB now supports Fission DWP file format version 2.
2037 http://gcc.gnu.org/wiki/DebugFission
2039 * New convenience function "$_isvoid", to check whether an expression
2040 is void. A void expression is an expression where the type of the
2041 result is "void". For example, some convenience variables may be
2042 "void" when evaluated (e.g., "$_exitcode" before the execution of
2043 the program being debugged; or an undefined convenience variable).
2044 Another example, when calling a function whose return type is
2047 * The "maintenance print objfiles" command now takes an optional regexp.
2049 * The "catch syscall" command now works on arm*-linux* targets.
2051 * GDB now consistently shows "<not saved>" when printing values of
2052 registers the debug info indicates have not been saved in the frame
2053 and there's nowhere to retrieve them from
2054 (callee-saved/call-clobbered registers):
2059 (gdb) info registers rax
2062 Before, the former would print "<optimized out>", and the latter
2063 "*value not available*".
2065 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2070 ** Frame filters and frame decorators have been added.
2071 ** Temporary breakpoints are now supported.
2072 ** Line tables representation has been added.
2073 ** New attribute 'parent_type' for gdb.Field objects.
2074 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2075 ** New attribute 'name' for gdb.Type objects.
2079 Nios II ELF nios2*-*-elf
2080 Nios II GNU/Linux nios2*-*-linux
2081 Texas Instruments MSP430 msp430*-*-elf
2083 * Removed native configurations
2085 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2086 been removed. ELF variants of these configurations are kept supported.
2088 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2089 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2090 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2091 i[34567]86-*-openbsd3.[0-3]
2092 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2093 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2094 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2098 Like "catch throw", but catches a re-thrown exception.
2099 maint check-psymtabs
2100 Renamed from old "maint check-symtabs".
2102 Perform consistency checks on symtabs.
2103 maint expand-symtabs
2104 Expand symtabs matching an optional regexp.
2107 Display the details of GDB configure-time options.
2109 maint set|show per-command
2110 maint set|show per-command space
2111 maint set|show per-command time
2112 maint set|show per-command symtab
2113 Enable display of per-command gdb resource usage.
2115 remove-symbol-file FILENAME
2116 remove-symbol-file -a ADDRESS
2117 Remove a symbol file added via add-symbol-file. The file to remove
2118 can be identified by its filename or by an address that lies within
2119 the boundaries of this symbol file in memory.
2122 info exceptions REGEXP
2123 Display the list of Ada exceptions defined in the program being
2124 debugged. If provided, only the exceptions whose names match REGEXP
2129 set debug symfile off|on
2131 Control display of debugging info regarding reading symbol files and
2132 symbol tables within those files
2134 set print raw frame-arguments
2135 show print raw frame-arguments
2136 Set/show whether to print frame arguments in raw mode,
2137 disregarding any defined pretty-printers.
2139 set remote trace-status-packet
2140 show remote trace-status-packet
2141 Set/show the use of remote protocol qTStatus packet.
2145 Control display of debugging messages related to Nios II targets.
2149 Control whether target-assisted range stepping is enabled.
2151 set startup-with-shell
2152 show startup-with-shell
2153 Specifies whether Unix child processes are started via a shell or
2158 Use the target memory cache for accesses to the code segment. This
2159 improves performance of remote debugging (particularly disassembly).
2161 * You can now use a literal value 'unlimited' for options that
2162 interpret 0 or -1 as meaning "unlimited". E.g., "set
2163 trace-buffer-size unlimited" is now an alias for "set
2164 trace-buffer-size -1" and "set height unlimited" is now an alias for
2167 * The "set debug symtab-create" debugging option of GDB has been changed to
2168 accept a verbosity level. 0 means "off", 1 provides basic debugging
2169 output, and values of 2 or greater provides more verbose output.
2171 * New command-line options
2173 Display the details of GDB configure-time options.
2175 * The command 'tsave' can now support new option '-ctf' to save trace
2176 buffer in Common Trace Format.
2178 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2181 * GDB now implements the the C++ 'typeid' operator.
2183 * The new convenience variable $_exception holds the exception being
2184 thrown or caught at an exception-related catchpoint.
2186 * The exception-related catchpoints, like "catch throw", now accept a
2187 regular expression which can be used to filter exceptions by type.
2189 * The new convenience variable $_exitsignal is automatically set to
2190 the terminating signal number when the program being debugged dies
2191 due to an uncaught signal.
2195 ** All MI commands now accept an optional "--language" option.
2196 Support for this feature can be verified by using the "-list-features"
2197 command, which should contain "language-option".
2199 ** The new command -info-gdb-mi-command allows the user to determine
2200 whether a GDB/MI command is supported or not.
2202 ** The "^error" result record returned when trying to execute an undefined
2203 GDB/MI command now provides a variable named "code" whose content is the
2204 "undefined-command" error code. Support for this feature can be verified
2205 by using the "-list-features" command, which should contain
2206 "undefined-command-error-code".
2208 ** The -trace-save MI command can optionally save trace buffer in Common
2211 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2213 ** The command -data-list-register-values now accepts an optional
2214 "--skip-unavailable" option. When used, only the available registers
2217 ** The new command -trace-frame-collected dumps collected variables,
2218 computed expressions, tvars, memory and registers in a traceframe.
2220 ** The commands -stack-list-locals, -stack-list-arguments and
2221 -stack-list-variables now accept an option "--skip-unavailable".
2222 When used, only the available locals or arguments are displayed.
2224 ** The -exec-run command now accepts an optional "--start" option.
2225 When used, the command follows the same semantics as the "start"
2226 command, stopping the program's execution at the start of its
2227 main subprogram. Support for this feature can be verified using
2228 the "-list-features" command, which should contain
2229 "exec-run-start-option".
2231 ** The new commands -catch-assert and -catch-exceptions insert
2232 catchpoints stopping the program when Ada exceptions are raised.
2234 ** The new command -info-ada-exceptions provides the equivalent of
2235 the new "info exceptions" command.
2237 * New system-wide configuration scripts
2238 A GDB installation now provides scripts suitable for use as system-wide
2239 configuration scripts for the following systems:
2243 * GDB now supports target-assigned range stepping with remote targets.
2244 This improves the performance of stepping source lines by reducing
2245 the number of control packets from/to GDB. See "New remote packets"
2248 * GDB now understands the element 'tvar' in the XML traceframe info.
2249 It has the id of the collected trace state variables.
2251 * On S/390 targets that provide the transactional-execution feature,
2252 the program interruption transaction diagnostic block (TDB) is now
2253 represented as a number of additional "registers" in GDB.
2255 * New remote packets
2259 The vCont packet supports a new 'r' action, that tells the remote
2260 stub to step through an address range itself, without GDB
2261 involvemement at each single-step.
2263 qXfer:libraries-svr4:read's annex
2264 The previously unused annex of the qXfer:libraries-svr4:read packet
2265 is now used to support passing an argument list. The remote stub
2266 reports support for this argument list to GDB's qSupported query.
2267 The defined arguments are "start" and "prev", used to reduce work
2268 necessary for library list updating, resulting in significant
2271 * New features in the GDB remote stub, GDBserver
2273 ** GDBserver now supports target-assisted range stepping. Currently
2274 enabled on x86/x86_64 GNU/Linux targets.
2276 ** GDBserver now adds element 'tvar' in the XML in the reply to
2277 'qXfer:traceframe-info:read'. It has the id of the collected
2278 trace state variables.
2280 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2283 * New 'z' formatter for printing and examining memory, this displays the
2284 value as hexadecimal zero padded on the left to the size of the type.
2286 * GDB can now use Windows x64 unwinding data.
2288 * The "set remotebaud" command has been replaced by "set serial baud".
2289 Similarly, "show remotebaud" has been replaced by "show serial baud".
2290 The "set remotebaud" and "show remotebaud" commands are still available
2291 to provide backward compatibility with older versions of GDB.
2293 *** Changes in GDB 7.6
2295 * Target record has been renamed to record-full.
2296 Record/replay is now enabled with the "record full" command.
2297 This also affects settings that are associated with full record/replay
2298 that have been moved from "set/show record" to "set/show record full":
2300 set|show record full insn-number-max
2301 set|show record full stop-at-limit
2302 set|show record full memory-query
2304 * A new record target "record-btrace" has been added. The new target
2305 uses hardware support to record the control-flow of a process. It
2306 does not support replaying the execution, but it implements the
2307 below new commands for investigating the recorded execution log.
2308 This new recording method can be enabled using:
2312 The "record-btrace" target is only available on Intel Atom processors
2313 and requires a Linux kernel 2.6.32 or later.
2315 * Two new commands have been added for record/replay to give information
2316 about the recorded execution without having to replay the execution.
2317 The commands are only supported by "record btrace".
2319 record instruction-history prints the execution history at
2320 instruction granularity
2322 record function-call-history prints the execution history at
2323 function granularity
2325 * New native configurations
2327 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2328 FreeBSD/powerpc powerpc*-*-freebsd
2329 x86_64/Cygwin x86_64-*-cygwin*
2330 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2334 ARM AArch64 aarch64*-*-elf
2335 ARM AArch64 GNU/Linux aarch64*-*-linux
2336 Lynx 178 PowerPC powerpc-*-lynx*178
2337 x86_64/Cygwin x86_64-*-cygwin*
2338 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2340 * If the configured location of system.gdbinit file (as given by the
2341 --with-system-gdbinit option at configure time) is in the
2342 data-directory (as specified by --with-gdb-datadir at configure
2343 time) or in one of its subdirectories, then GDB will look for the
2344 system-wide init file in the directory specified by the
2345 --data-directory command-line option.
2347 * New command line options:
2349 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2350 other initialization files, unlike -nx which disables all of them.
2352 * Removed command line options
2354 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2357 * The 'ptype' and 'whatis' commands now accept an argument to control
2360 * 'info proc' now works on some core files.
2364 ** Vectors can be created with gdb.Type.vector.
2366 ** Python's atexit.register now works in GDB.
2368 ** Types can be pretty-printed via a Python API.
2370 ** Python 3 is now supported (in addition to Python 2.4 or later)
2372 ** New class gdb.Architecture exposes GDB's internal representation
2373 of architecture in the Python API.
2375 ** New method Frame.architecture returns the gdb.Architecture object
2376 corresponding to the frame's architecture.
2378 * New Python-based convenience functions:
2380 ** $_memeq(buf1, buf2, length)
2381 ** $_streq(str1, str2)
2383 ** $_regex(str, regex)
2385 * The 'cd' command now defaults to using '~' (the home directory) if not
2388 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2389 default for GCC since November 2000.
2391 * The command 'forward-search' can now be abbreviated as 'fo'.
2393 * The command 'info tracepoints' can now display 'installed on target'
2394 or 'not installed on target' for each non-pending location of tracepoint.
2396 * New configure options
2398 --enable-libmcheck/--disable-libmcheck
2399 By default, development versions are built with -lmcheck on hosts
2400 that support it, in order to help track memory corruption issues.
2401 Release versions, on the other hand, are built without -lmcheck
2402 by default. The --enable-libmcheck/--disable-libmcheck configure
2403 options allow the user to override that default.
2404 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2405 This configure option allows the user to build GDB with
2406 libbabeltrace using which GDB can read Common Trace Format data.
2408 * New commands (for set/show, see "New options" below)
2411 Catch signals. This is similar to "handle", but allows commands and
2412 conditions to be attached.
2415 List the BFDs known to GDB.
2417 python-interactive [command]
2419 Start a Python interactive prompt, or evaluate the optional command
2420 and print the result of expressions.
2423 "py" is a new alias for "python".
2425 enable type-printer [name]...
2426 disable type-printer [name]...
2427 Enable or disable type printers.
2431 ** For the Renesas Super-H architecture, the "regs" command has been removed
2432 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2437 set print type methods (on|off)
2438 show print type methods
2439 Control whether method declarations are displayed by "ptype".
2440 The default is to show them.
2442 set print type typedefs (on|off)
2443 show print type typedefs
2444 Control whether typedef definitions are displayed by "ptype".
2445 The default is to show them.
2447 set filename-display basename|relative|absolute
2448 show filename-display
2449 Control the way in which filenames is displayed.
2450 The default is "relative", which preserves previous behavior.
2452 set trace-buffer-size
2453 show trace-buffer-size
2454 Request target to change the size of trace buffer.
2456 set remote trace-buffer-size-packet auto|on|off
2457 show remote trace-buffer-size-packet
2458 Control the use of the remote protocol `QTBuffer:size' packet.
2462 Control display of debugging messages related to ARM AArch64.
2465 set debug coff-pe-read
2466 show debug coff-pe-read
2467 Control display of debugging messages related to reading of COFF/PE
2472 Control display of debugging messages related to Mach-O symbols
2475 set debug notification
2476 show debug notification
2477 Control display of debugging info for async remote notification.
2481 ** Command parameter changes are now notified using new async record
2482 "=cmd-param-changed".
2483 ** Trace frame changes caused by command "tfind" are now notified using
2484 new async record "=traceframe-changed".
2485 ** The creation, deletion and modification of trace state variables
2486 are now notified using new async records "=tsv-created",
2487 "=tsv-deleted" and "=tsv-modified".
2488 ** The start and stop of process record are now notified using new
2489 async record "=record-started" and "=record-stopped".
2490 ** Memory changes are now notified using new async record
2492 ** The data-disassemble command response will include a "fullname" field
2493 containing the absolute file name when source has been requested.
2494 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2495 command, to allow pattern filling of memory areas.
2496 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2497 library load/unload events.
2498 ** The response to breakpoint commands and breakpoint async records
2499 includes an "installed" field containing a boolean state about each
2500 non-pending tracepoint location is whether installed on target or not.
2501 ** Output of the "-trace-status" command includes a "trace-file" field
2502 containing the name of the trace file being examined. This field is
2503 optional, and only present when examining a trace file.
2504 ** The "fullname" field is now always present along with the "file" field,
2505 even if the file cannot be found by GDB.
2507 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2508 You must have the LZMA library available when configuring GDB for this
2509 feature to be enabled. For more information, see:
2510 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2512 * New remote packets
2515 Set the size of trace buffer. The remote stub reports support for this
2516 packet to gdb's qSupported query.
2519 Enable Branch Trace Store (BTS)-based branch tracing for the current
2520 thread. The remote stub reports support for this packet to gdb's
2524 Disable branch tracing for the current thread. The remote stub reports
2525 support for this packet to gdb's qSupported query.
2528 Read the traced branches for the current thread. The remote stub
2529 reports support for this packet to gdb's qSupported query.
2531 *** Changes in GDB 7.5
2533 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2534 for more x32 ABI info.
2536 * GDB now supports access to MIPS DSP registers on Linux targets.
2538 * GDB now supports debugging microMIPS binaries.
2540 * The "info os" command on GNU/Linux can now display information on
2541 several new classes of objects managed by the operating system:
2542 "info os procgroups" lists process groups
2543 "info os files" lists file descriptors
2544 "info os sockets" lists internet-domain sockets
2545 "info os shm" lists shared-memory regions
2546 "info os semaphores" lists semaphores
2547 "info os msg" lists message queues
2548 "info os modules" lists loaded kernel modules
2550 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2551 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2552 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2553 options and inspect the probe arguments using the new $_probe_arg family
2554 of convenience variables. You can obtain more information about SystemTap
2555 in <http://sourceware.org/systemtap/>.
2557 * GDB now supports reversible debugging on ARM, it allows you to
2558 debug basic ARM and THUMB instructions, and provides
2559 record/replay support.
2561 * The option "symbol-reloading" has been deleted as it is no longer used.
2565 ** GDB commands implemented in Python can now be put in command class
2568 ** The "maint set python print-stack on|off" is now deleted.
2570 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2571 apply "flag enum"-style pretty-printing to any enum.
2573 ** gdb.lookup_symbol can now work when there is no current frame.
2575 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2576 the source at which the symbol was defined.
2578 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2579 method 'value'. The former indicates whether the symbol needs a
2580 frame in order to compute its value, and the latter computes the
2583 ** A new method 'referenced_value' on gdb.Value objects which can
2584 dereference pointer as well as C++ reference values.
2586 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2587 which return the global and static blocks (as gdb.Block objects),
2588 of the underlying symbol table, respectively.
2590 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2591 object associated with a PC value.
2593 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2594 of the address range occupied by code for the current source line.
2596 * Go language support.
2597 GDB now supports debugging programs written in the Go programming
2600 * GDBserver now supports stdio connections.
2601 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2603 * The binary "gdbtui" can no longer be built or installed.
2604 Use "gdb -tui" instead.
2606 * GDB will now print "flag" enums specially. A flag enum is one where
2607 all the enumerator values have no bits in common when pairwise
2608 "and"ed. When printing a value whose type is a flag enum, GDB will
2609 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2610 (gdb) print (enum E) 3
2613 * The filename part of a linespec will now match trailing components
2614 of a source file name. For example, "break gcc/expr.c:1000" will
2615 now set a breakpoint in build/gcc/expr.c, but not
2616 build/libcpp/expr.c.
2618 * The "info proc" and "generate-core-file" commands will now also
2619 work on remote targets connected to GDBserver on Linux.
2621 * The command "info catch" has been removed. It has been disabled
2622 since December 2007.
2624 * The "catch exception" and "catch assert" commands now accept
2625 a condition at the end of the command, much like the "break"
2626 command does. For instance:
2628 (gdb) catch exception Constraint_Error if Barrier = True
2630 Previously, it was possible to add a condition to such catchpoints,
2631 but it had to be done as a second step, after the catchpoint had been
2632 created, using the "condition" command.
2634 * The "info static-tracepoint-marker" command will now also work on
2635 native Linux targets with in-process agent.
2637 * GDB can now set breakpoints on inlined functions.
2639 * The .gdb_index section has been updated to include symbols for
2640 inlined functions. GDB will ignore older .gdb_index sections by
2641 default, which could cause symbol files to be loaded more slowly
2642 until their .gdb_index sections can be recreated. The new command
2643 "set use-deprecated-index-sections on" will cause GDB to use any older
2644 .gdb_index sections it finds. This will restore performance, but the
2645 ability to set breakpoints on inlined functions will be lost in symbol
2646 files with older .gdb_index sections.
2648 The .gdb_index section has also been updated to record more information
2649 about each symbol. This speeds up the "info variables", "info functions"
2650 and "info types" commands when used with programs having the .gdb_index
2651 section, as well as speeding up debugging with shared libraries using
2652 the .gdb_index section.
2654 * Ada support for GDB/MI Variable Objects has been added.
2656 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2661 ** New command -info-os is the MI equivalent of "info os".
2663 ** Output logs ("set logging" and related) now include MI output.
2667 ** "set use-deprecated-index-sections on|off"
2668 "show use-deprecated-index-sections on|off"
2669 Controls the use of deprecated .gdb_index sections.
2671 ** "catch load" and "catch unload" can be used to stop when a shared
2672 library is loaded or unloaded, respectively.
2674 ** "enable count" can be used to auto-disable a breakpoint after
2677 ** "info vtbl" can be used to show the virtual method tables for
2678 C++ and Java objects.
2680 ** "explore" and its sub commands "explore value" and "explore type"
2681 can be used to recursively explore values and types of
2682 expressions. These commands are available only if GDB is
2683 configured with '--with-python'.
2685 ** "info auto-load" shows status of all kinds of auto-loaded files,
2686 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2687 sequences of commands files, "info auto-load python-scripts"
2688 shows status of auto-loading Python script files,
2689 "info auto-load local-gdbinit" shows status of loading init file
2690 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2691 status of inferior specific thread debugging shared library loading.
2693 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2694 and "show auto-load-scripts" commands have been deprecated, use their
2695 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2696 and "show auto-load python-scripts" counterparts instead.
2698 ** "dprintf location,format,args..." creates a dynamic printf, which
2699 is basically a breakpoint that does a printf and immediately
2700 resumes your program's execution, so it is like a printf that you
2701 can insert dynamically at runtime instead of at compiletime.
2703 ** "set print symbol"
2705 Controls whether GDB attempts to display the symbol, if any,
2706 corresponding to addresses it prints. This defaults to "on", but
2707 you can set it to "off" to restore GDB's previous behavior.
2709 * Deprecated commands
2711 ** For the Renesas Super-H architecture, the "regs" command has been
2712 deprecated, and "info all-registers" should be used instead.
2716 Renesas RL78 rl78-*-elf
2717 HP OpenVMS ia64 ia64-hp-openvms*
2719 * GDBserver supports evaluation of breakpoint conditions. When
2720 support is advertised by GDBserver, GDB may be told to send the
2721 breakpoint conditions in bytecode form to GDBserver. GDBserver
2722 will only report the breakpoint trigger to GDB when its condition
2727 set mips compression
2728 show mips compression
2729 Select the compressed ISA encoding used in functions that have no symbol
2730 information available. The encoding can be set to either of:
2733 and is updated automatically from ELF file flags if available.
2735 set breakpoint condition-evaluation
2736 show breakpoint condition-evaluation
2737 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2738 GDBserver ("target"). Default option "auto" chooses the most efficient
2740 This option can improve debugger efficiency depending on the speed of the
2744 Disable auto-loading globally.
2747 Show auto-loading setting of all kinds of auto-loaded files.
2749 set auto-load gdb-scripts on|off
2750 show auto-load gdb-scripts
2751 Control auto-loading of GDB canned sequences of commands files.
2753 set auto-load python-scripts on|off
2754 show auto-load python-scripts
2755 Control auto-loading of Python script files.
2757 set auto-load local-gdbinit on|off
2758 show auto-load local-gdbinit
2759 Control loading of init file (.gdbinit) from current directory.
2761 set auto-load libthread-db on|off
2762 show auto-load libthread-db
2763 Control auto-loading of inferior specific thread debugging shared library.
2765 set auto-load scripts-directory <dir1>[:<dir2>...]
2766 show auto-load scripts-directory
2767 Set a list of directories from which to load auto-loaded scripts.
2768 Automatically loaded Python scripts and GDB scripts are located in one
2769 of the directories listed by this option.
2770 The delimiter (':' above) may differ according to the host platform.
2772 set auto-load safe-path <dir1>[:<dir2>...]
2773 show auto-load safe-path
2774 Set a list of directories from which it is safe to auto-load files.
2775 The delimiter (':' above) may differ according to the host platform.
2777 set debug auto-load on|off
2778 show debug auto-load
2779 Control display of debugging info for auto-loading the files above.
2781 set dprintf-style gdb|call|agent
2783 Control the way in which a dynamic printf is performed; "gdb"
2784 requests a GDB printf command, while "call" causes dprintf to call a
2785 function in the inferior. "agent" requests that the target agent
2786 (such as GDBserver) do the printing.
2788 set dprintf-function <expr>
2789 show dprintf-function
2790 set dprintf-channel <expr>
2791 show dprintf-channel
2792 Set the function and optional first argument to the call when using
2793 the "call" style of dynamic printf.
2795 set disconnected-dprintf on|off
2796 show disconnected-dprintf
2797 Control whether agent-style dynamic printfs continue to be in effect
2798 after GDB disconnects.
2800 * New configure options
2802 --with-auto-load-dir
2803 Configure default value for the 'set auto-load scripts-directory'
2804 setting above. It defaults to '$debugdir:$datadir/auto-load',
2805 $debugdir representing global debugging info directories (available
2806 via 'show debug-file-directory') and $datadir representing GDB's data
2807 directory (available via 'show data-directory').
2809 --with-auto-load-safe-path
2810 Configure default value for the 'set auto-load safe-path' setting
2811 above. It defaults to the --with-auto-load-dir setting.
2813 --without-auto-load-safe-path
2814 Set 'set auto-load safe-path' to '/', effectively disabling this
2817 * New remote packets
2819 z0/z1 conditional breakpoints extension
2821 The z0/z1 breakpoint insertion packets have been extended to carry
2822 a list of conditional expressions over to the remote stub depending on the
2823 condition evaluation mode. The use of this extension can be controlled
2824 via the "set remote conditional-breakpoints-packet" command.
2828 Specify the signals which the remote stub may pass to the debugged
2829 program without GDB involvement.
2831 * New command line options
2833 --init-command=FILE, -ix Like --command, -x but execute it
2834 before loading inferior.
2835 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2836 execute it before loading inferior.
2838 *** Changes in GDB 7.4
2840 * GDB now handles ambiguous linespecs more consistently; the existing
2841 FILE:LINE support has been expanded to other types of linespecs. A
2842 breakpoint will now be set on all matching locations in all
2843 inferiors, and locations will be added or removed according to
2846 * GDB now allows you to skip uninteresting functions and files when
2847 stepping with the "skip function" and "skip file" commands.
2849 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2850 and "show remote hardware-watchpoint-length-limit". These allows to
2851 set or show the maximum length limit (in bytes) of a remote
2852 target hardware watchpoint.
2854 This allows e.g. to use "unlimited" hardware watchpoints with the
2855 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2856 watchpoints are slower than real hardware watchpoints but are
2857 significantly faster than gdb software watchpoints.
2861 ** The register_pretty_printer function in module gdb.printing now takes
2862 an optional `replace' argument. If True, the new printer replaces any
2865 ** The "maint set python print-stack on|off" command has been
2866 deprecated and will be deleted in GDB 7.5.
2867 A new command: "set python print-stack none|full|message" has
2868 replaced it. Additionally, the default for "print-stack" is
2869 now "message", which just prints the error message without
2872 ** A prompt substitution hook (prompt_hook) is now available to the
2875 ** A new Python module, gdb.prompt has been added to the GDB Python
2876 modules library. This module provides functionality for
2877 escape sequences in prompts (used by set/show
2878 extended-prompt). These escape sequences are replaced by their
2879 corresponding value.
2881 ** Python commands and convenience-functions located in
2882 'data-directory'/python/gdb/command and
2883 'data-directory'/python/gdb/function are now automatically loaded
2886 ** Blocks now provide four new attributes. global_block and
2887 static_block will return the global and static blocks
2888 respectively. is_static and is_global are boolean attributes
2889 that indicate if the block is one of those two types.
2891 ** Symbols now provide the "type" attribute, the type of the symbol.
2893 ** The "gdb.breakpoint" function has been deprecated in favor of
2896 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2897 of a function. This class is based on the "finish" command
2898 available in the CLI.
2900 ** Type objects for struct and union types now allow access to
2901 the fields using standard Python dictionary (mapping) methods.
2902 For example, "some_type['myfield']" now works, as does
2903 "some_type.items()".
2905 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2908 ** A new function, "deep_items" has been added to the gdb.types
2909 module in the GDB Python modules library. This function returns
2910 an iterator over the fields of a struct or union type. Unlike
2911 the standard Python "iteritems" method, it will recursively traverse
2912 any anonymous fields.
2916 ** "*stopped" events can report several new "reason"s, such as
2919 ** Breakpoint changes are now notified using new async records, like
2920 "=breakpoint-modified".
2922 ** New command -ada-task-info.
2924 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2925 $sdir specifies the default system locations of shared libraries.
2926 $pdir specifies the directory where the libpthread used by the application
2929 GDB no longer looks in $sdir and $pdir after it has searched the directories
2930 mentioned in libthread-db-search-path. If you want to search those
2931 directories, they must be specified in libthread-db-search-path.
2932 The default value of libthread-db-search-path on GNU/Linux and Solaris
2933 systems is now "$sdir:$pdir".
2935 $pdir is not supported by gdbserver, it is currently ignored.
2936 $sdir is supported by gdbserver.
2938 * New configure option --with-iconv-bin.
2939 When using the internationalization support like the one in the GNU C
2940 library, GDB will invoke the "iconv" program to get a list of supported
2941 character sets. If this program lives in a non-standard location, one can
2942 use this option to specify where to find it.
2944 * When natively debugging programs on PowerPC BookE processors running
2945 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2946 watchpoints, which specify a mask in addition to an address to watch.
2947 The mask specifies that some bits of an address (the bits which are
2948 reset in the mask) should be ignored when matching the address accessed
2949 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2950 section in the user manual for more details.
2952 * The new option --once causes GDBserver to stop listening for connections once
2953 the first connection is made. The listening port used by GDBserver will
2954 become available after that.
2956 * New commands "info macros" and "alias" have been added.
2958 * New function parameters suffix @entry specifies value of function parameter
2959 at the time the function got called. Entry values are available only since
2965 "!" is now an alias of the "shell" command.
2966 Note that no space is needed between "!" and SHELL COMMAND.
2970 watch EXPRESSION mask MASK_VALUE
2971 The watch command now supports the mask argument which allows creation
2972 of masked watchpoints, if the current architecture supports this feature.
2974 info auto-load-scripts [REGEXP]
2975 This command was formerly named "maintenance print section-scripts".
2976 It is now generally useful and is no longer a maintenance-only command.
2978 info macro [-all] [--] MACRO
2979 The info macro command has new options `-all' and `--'. The first for
2980 printing all definitions of a macro. The second for explicitly specifying
2981 the end of arguments and the beginning of the macro name in case the macro
2982 name starts with a hyphen.
2984 collect[/s] EXPRESSIONS
2985 The tracepoint collect command now takes an optional modifier "/s"
2986 that directs it to dereference pointer-to-character types and
2987 collect the bytes of memory up to a zero byte. The behavior is
2988 similar to what you see when you use the regular print command on a
2989 string. An optional integer following the "/s" sets a bound on the
2990 number of bytes that will be collected.
2993 The trace start command now interprets any supplied arguments as a
2994 note to be recorded with the trace run, with an effect similar to
2995 setting the variable trace-notes.
2998 The trace stop command now interprets any arguments as a note to be
2999 mentioned along with the tstatus report that the trace was stopped
3000 with a command. The effect is similar to setting the variable
3003 * Tracepoints can now be enabled and disabled at any time after a trace
3004 experiment has been started using the standard "enable" and "disable"
3005 commands. It is now possible to start a trace experiment with no enabled
3006 tracepoints; GDB will display a warning, but will allow the experiment to
3007 begin, assuming that tracepoints will be enabled as needed while the trace
3010 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3011 locations with 4-byte instructions, when they were previously
3012 limited to locations with instructions of 5 bytes or longer.
3016 set debug dwarf2-read
3017 show debug dwarf2-read
3018 Turns on or off display of debugging messages related to reading
3019 DWARF debug info. The default is off.
3021 set debug symtab-create
3022 show debug symtab-create
3023 Turns on or off display of debugging messages related to symbol table
3024 creation. The default is off.
3027 show extended-prompt
3028 Set the GDB prompt, and allow escape sequences to be inserted to
3029 display miscellaneous information (see 'help set extended-prompt'
3030 for the list of sequences). This prompt (and any information
3031 accessed through the escape sequences) is updated every time the
3032 prompt is displayed.
3034 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3035 show print entry-values
3036 Set printing of frame argument values at function entry. In some cases
3037 GDB can determine the value of function argument which was passed by the
3038 function caller, even if the value was modified inside the called function.
3040 set debug entry-values
3041 show debug entry-values
3042 Control display of debugging info for determining frame argument values at
3043 function entry and virtual tail call frames.
3045 set basenames-may-differ
3046 show basenames-may-differ
3047 Set whether a source file may have multiple base names.
3048 (A "base name" is the name of a file with the directory part removed.
3049 Example: The base name of "/home/user/hello.c" is "hello.c".)
3050 If set, GDB will canonicalize file names (e.g., expand symlinks)
3051 before comparing them. Canonicalization is an expensive operation,
3052 but it allows the same file be known by more than one base name.
3053 If not set (the default), all source files are assumed to have just
3054 one base name, and gdb will do file name comparisons more efficiently.
3060 Set a user name and notes for the current and any future trace runs.
3061 This is useful for long-running and/or disconnected traces, to
3062 inform others (or yourself) as to who is running the trace, supply
3063 contact information, or otherwise explain what is going on.
3065 set trace-stop-notes
3066 show trace-stop-notes
3067 Set a note attached to the trace run, that is displayed when the
3068 trace has been stopped by a tstop command. This is useful for
3069 instance as an explanation, if you are stopping a trace run that was
3070 started by someone else.
3072 * New remote packets
3076 Dynamically enable a tracepoint in a started trace experiment.
3080 Dynamically disable a tracepoint in a started trace experiment.
3084 Set the user and notes of the trace run.
3088 Query the current status of a tracepoint.
3092 Query the minimum length of instruction at which a fast tracepoint may
3095 * Dcache size (number of lines) and line-size are now runtime-configurable
3096 via "set dcache line" and "set dcache line-size" commands.
3100 Texas Instruments TMS320C6x tic6x-*-*
3104 Renesas RL78 rl78-*-elf
3106 *** Changes in GDB 7.3.1
3108 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3110 *** Changes in GDB 7.3
3112 * GDB has a new command: "thread find [REGEXP]".
3113 It finds the thread id whose name, target id, or thread extra info
3114 matches the given regular expression.
3116 * The "catch syscall" command now works on mips*-linux* targets.
3118 * The -data-disassemble MI command now supports modes 2 and 3 for
3119 dumping the instruction opcodes.
3121 * New command line options
3123 -data-directory DIR Specify DIR as the "data-directory".
3124 This is mostly for testing purposes.
3126 * The "maint set python auto-load on|off" command has been renamed to
3127 "set auto-load-scripts on|off".
3129 * GDB has a new command: "set directories".
3130 It is like the "dir" command except that it replaces the
3131 source path list instead of augmenting it.
3133 * GDB now understands thread names.
3135 On GNU/Linux, "info threads" will display the thread name as set by
3136 prctl or pthread_setname_np.
3138 There is also a new command, "thread name", which can be used to
3139 assign a name internally for GDB to display.
3142 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3143 has been integrated into GDB.
3147 ** The function gdb.Write now accepts an optional keyword 'stream'.
3148 This keyword, when provided, will direct the output to either
3149 stdout, stderr, or GDB's logging output.
3151 ** Parameters can now be be sub-classed in Python, and in particular
3152 you may implement the get_set_doc and get_show_doc functions.
3153 This improves how Parameter set/show documentation is processed
3154 and allows for more dynamic content.
3156 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3157 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3158 have an is_valid method.
3160 ** Breakpoints can now be sub-classed in Python, and in particular
3161 you may implement a 'stop' function that is executed each time
3162 the inferior reaches that breakpoint.
3164 ** New function gdb.lookup_global_symbol looks up a global symbol.
3166 ** GDB values in Python are now callable if the value represents a
3167 function. For example, if 'some_value' represents a function that
3168 takes two integer parameters and returns a value, you can call
3169 that function like so:
3171 result = some_value (10,20)
3173 ** Module gdb.types has been added.
3174 It contains a collection of utilities for working with gdb.Types objects:
3175 get_basic_type, has_field, make_enum_dict.
3177 ** Module gdb.printing has been added.
3178 It contains utilities for writing and registering pretty-printers.
3179 New classes: PrettyPrinter, SubPrettyPrinter,
3180 RegexpCollectionPrettyPrinter.
3181 New function: register_pretty_printer.
3183 ** New commands "info pretty-printers", "enable pretty-printer" and
3184 "disable pretty-printer" have been added.
3186 ** gdb.parameter("directories") is now available.
3188 ** New function gdb.newest_frame returns the newest frame in the
3191 ** The gdb.InferiorThread class has a new "name" attribute. This
3192 holds the thread's name.
3194 ** Python Support for Inferior events.
3195 Python scripts can add observers to be notified of events
3196 occurring in the process being debugged.
3197 The following events are currently supported:
3198 - gdb.events.cont Continue event.
3199 - gdb.events.exited Inferior exited event.
3200 - gdb.events.stop Signal received, and Breakpoint hit events.
3204 ** GDB now puts template parameters in scope when debugging in an
3205 instantiation. For example, if you have:
3207 template<int X> int func (void) { return X; }
3209 then if you step into func<5>, "print X" will show "5". This
3210 feature requires proper debuginfo support from the compiler; it
3211 was added to GCC 4.5.
3213 ** The motion commands "next", "finish", "until", and "advance" now
3214 work better when exceptions are thrown. In particular, GDB will
3215 no longer lose control of the inferior; instead, the GDB will
3216 stop the inferior at the point at which the exception is caught.
3217 This functionality requires a change in the exception handling
3218 code that was introduced in GCC 4.5.
3220 * GDB now follows GCC's rules on accessing volatile objects when
3221 reading or writing target state during expression evaluation.
3222 One notable difference to prior behavior is that "print x = 0"
3223 no longer generates a read of x; the value of the assignment is
3224 now always taken directly from the value being assigned.
3226 * GDB now has some support for using labels in the program's source in
3227 linespecs. For instance, you can use "advance label" to continue
3228 execution to a label.
3230 * GDB now has support for reading and writing a new .gdb_index
3231 section. This section holds a fast index of DWARF debugging
3232 information and can be used to greatly speed up GDB startup and
3233 operation. See the documentation for `save gdb-index' for details.
3235 * The "watch" command now accepts an optional "-location" argument.
3236 When used, this causes GDB to watch the memory referred to by the
3237 expression. Such a watchpoint is never deleted due to it going out
3240 * GDB now supports thread debugging of core dumps on GNU/Linux.
3242 GDB now activates thread debugging using the libthread_db library
3243 when debugging GNU/Linux core dumps, similarly to when debugging
3244 live processes. As a result, when debugging a core dump file, GDB
3245 is now able to display pthread_t ids of threads. For example, "info
3246 threads" shows the same output as when debugging the process when it
3247 was live. In earlier releases, you'd see something like this:
3250 * 1 LWP 6780 main () at main.c:10
3252 While now you see this:
3255 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3257 It is also now possible to inspect TLS variables when debugging core
3260 When debugging a core dump generated on a machine other than the one
3261 used to run GDB, you may need to point GDB at the correct
3262 libthread_db library with the "set libthread-db-search-path"
3263 command. See the user manual for more details on this command.
3265 * When natively debugging programs on PowerPC BookE processors running
3266 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3267 which stop execution of the inferior whenever it executes an instruction
3268 at any address within the specified range. See the "PowerPC Embedded"
3269 section in the user manual for more details.
3271 * New features in the GDB remote stub, GDBserver
3273 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3274 and i686 LynxOS (version 5.x).
3276 ** GDBserver is now supported on Blackfin Linux.
3278 * New native configurations
3280 ia64 HP-UX ia64-*-hpux*
3284 Analog Devices, Inc. Blackfin Processor bfin-*
3286 * Ada task switching is now supported on sparc-elf targets when
3287 debugging a program using the Ravenscar Profile. For more information,
3288 see the "Tasking Support when using the Ravenscar Profile" section
3289 in the GDB user manual.
3291 * Guile support was removed.
3293 * New features in the GNU simulator
3295 ** The --map-info flag lists all known core mappings.
3297 ** CFI flashes may be simulated via the "cfi" device.
3299 *** Changes in GDB 7.2
3301 * Shared library support for remote targets by default
3303 When GDB is configured for a generic, non-OS specific target, like
3304 for example, --target=arm-eabi or one of the many *-*-elf targets,
3305 GDB now queries remote stubs for loaded shared libraries using the
3306 `qXfer:libraries:read' packet. Previously, shared library support
3307 was always disabled for such configurations.
3311 ** Argument Dependent Lookup (ADL)
3313 In C++ ADL lookup directs function search to the namespaces of its
3314 arguments even if the namespace has not been imported.
3324 Here the compiler will search for `foo' in the namespace of 'b'
3325 and find A::foo. GDB now supports this. This construct is commonly
3326 used in the Standard Template Library for operators.
3328 ** Improved User Defined Operator Support
3330 In addition to member operators, GDB now supports lookup of operators
3331 defined in a namespace and imported with a `using' directive, operators
3332 defined in the global scope, operators imported implicitly from an
3333 anonymous namespace, and the ADL operators mentioned in the previous
3335 GDB now also supports proper overload resolution for all the previously
3336 mentioned flavors of operators.
3338 ** static const class members
3340 Printing of static const class members that are initialized in the
3341 class definition has been fixed.
3343 * Windows Thread Information Block access.
3345 On Windows targets, GDB now supports displaying the Windows Thread
3346 Information Block (TIB) structure. This structure is visible either
3347 by using the new command `info w32 thread-information-block' or, by
3348 dereferencing the new convenience variable named `$_tlb', a
3349 thread-specific pointer to the TIB. This feature is also supported
3350 when remote debugging using GDBserver.
3352 * Static tracepoints
3354 Static tracepoints are calls in the user program into a tracing
3355 library. One such library is a port of the LTTng kernel tracer to
3356 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3357 When debugging with GDBserver, GDB now supports combining the GDB
3358 tracepoint machinery with such libraries. For example: the user can
3359 use GDB to probe a static tracepoint marker (a call from the user
3360 program into the tracing library) with the new "strace" command (see
3361 "New commands" below). This creates a "static tracepoint" in the
3362 breakpoint list, that can be manipulated with the same feature set
3363 as fast and regular tracepoints. E.g., collect registers, local and
3364 global variables, collect trace state variables, and define
3365 tracepoint conditions. In addition, the user can collect extra
3366 static tracepoint marker specific data, by collecting the new
3367 $_sdata internal variable. When analyzing the trace buffer, you can
3368 inspect $_sdata like any other variable available to GDB. For more
3369 information, see the "Tracepoints" chapter in GDB user manual. New
3370 remote packets have been defined to support static tracepoints, see
3371 the "New remote packets" section below.
3373 * Better reconstruction of tracepoints after disconnected tracing
3375 GDB will attempt to download the original source form of tracepoint
3376 definitions when starting a trace run, and then will upload these
3377 upon reconnection to the target, resulting in a more accurate
3378 reconstruction of the tracepoints that are in use on the target.
3382 You can now exercise direct control over the ways that GDB can
3383 affect your program. For instance, you can disallow the setting of
3384 breakpoints, so that the program can run continuously (assuming
3385 non-stop mode). In addition, the "observer" variable is available
3386 to switch all of the different controls; in observer mode, GDB
3387 cannot affect the target's behavior at all, which is useful for
3388 tasks like diagnosing live systems in the field.
3390 * The new convenience variable $_thread holds the number of the
3393 * New remote packets
3397 Return the address of the Windows Thread Information Block of a given thread.
3401 In response to several of the tracepoint packets, the target may now
3402 also respond with a number of intermediate `qRelocInsn' request
3403 packets before the final result packet, to have GDB handle
3404 relocating an instruction to execute at a different address. This
3405 is particularly useful for stubs that support fast tracepoints. GDB
3406 reports support for this feature in the qSupported packet.
3410 List static tracepoint markers in the target program.
3414 List static tracepoint markers at a given address in the target
3417 qXfer:statictrace:read
3419 Read the static trace data collected (by a `collect $_sdata'
3420 tracepoint action). The remote stub reports support for this packet
3421 to gdb's qSupported query.
3425 Send the current settings of GDB's permission flags.
3429 Send part of the source (textual) form of a tracepoint definition,
3430 which includes location, conditional, and action list.
3432 * The source command now accepts a -s option to force searching for the
3433 script in the source search path even if the script name specifies
3436 * New features in the GDB remote stub, GDBserver
3438 - GDBserver now support tracepoints (including fast tracepoints, and
3439 static tracepoints). The feature is currently supported by the
3440 i386-linux and amd64-linux builds. See the "Tracepoints support
3441 in gdbserver" section in the manual for more information.
3443 GDBserver JIT compiles the tracepoint's conditional agent
3444 expression bytecode into native code whenever possible for low
3445 overhead dynamic tracepoints conditionals. For such tracepoints,
3446 an expression that examines program state is evaluated when the
3447 tracepoint is reached, in order to determine whether to capture
3448 trace data. If the condition is simple and false, processing the
3449 tracepoint finishes very quickly and no data is gathered.
3451 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3452 for static tracepoints support.
3454 - GDBserver now supports x86_64 Windows 64-bit debugging.
3456 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3457 it understands register description.
3459 * The --batch flag now disables pagination and queries.
3461 * X86 general purpose registers
3463 GDB now supports reading/writing byte, word and double-word x86
3464 general purpose registers directly. This means you can use, say,
3465 $ah or $ax to refer, respectively, to the byte register AH and
3466 16-bit word register AX that are actually portions of the 32-bit
3467 register EAX or 64-bit register RAX.
3469 * The `commands' command now accepts a range of breakpoints to modify.
3470 A plain `commands' following a command that creates multiple
3471 breakpoints affects all the breakpoints set by that command. This
3472 applies to breakpoints set by `rbreak', and also applies when a
3473 single `break' command creates multiple breakpoints (e.g.,
3474 breakpoints on overloaded c++ functions).
3476 * The `rbreak' command now accepts a filename specification as part of
3477 its argument, limiting the functions selected by the regex to those
3478 in the specified file.
3480 * Support for remote debugging Windows and SymbianOS shared libraries
3481 from Unix hosts has been improved. Non Windows GDB builds now can
3482 understand target reported file names that follow MS-DOS based file
3483 system semantics, such as file names that include drive letters and
3484 use the backslash character as directory separator. This makes it
3485 possible to transparently use the "set sysroot" and "set
3486 solib-search-path" on Unix hosts to point as host copies of the
3487 target's shared libraries. See the new command "set
3488 target-file-system-kind" described below, and the "Commands to
3489 specify files" section in the user manual for more information.
3493 eval template, expressions...
3494 Convert the values of one or more expressions under the control
3495 of the string template to a command line, and call it.
3497 set target-file-system-kind unix|dos-based|auto
3498 show target-file-system-kind
3499 Set or show the assumed file system kind for target reported file
3502 save breakpoints <filename>
3503 Save all current breakpoint definitions to a file suitable for use
3504 in a later debugging session. To read the saved breakpoint
3505 definitions, use the `source' command.
3507 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3510 info static-tracepoint-markers
3511 Display information about static tracepoint markers in the target.
3513 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3514 Define a static tracepoint by probing a marker at the given
3515 function, line, address, or marker ID.
3519 Enable and disable observer mode.
3521 set may-write-registers on|off
3522 set may-write-memory on|off
3523 set may-insert-breakpoints on|off
3524 set may-insert-tracepoints on|off
3525 set may-insert-fast-tracepoints on|off
3526 set may-interrupt on|off
3527 Set individual permissions for GDB effects on the target. Note that
3528 some of these settings can have undesirable or surprising
3529 consequences, particularly when changed in the middle of a session.
3530 For instance, disabling the writing of memory can prevent
3531 breakpoints from being inserted, cause single-stepping to fail, or
3532 even crash your program, if you disable after breakpoints have been
3533 inserted. However, GDB should not crash.
3535 set record memory-query on|off
3536 show record memory-query
3537 Control whether to stop the inferior if memory changes caused
3538 by an instruction cannot be recorded.
3543 The disassemble command now supports "start,+length" form of two arguments.
3547 ** GDB now provides a new directory location, called the python directory,
3548 where Python scripts written for GDB can be installed. The location
3549 of that directory is <data-directory>/python, where <data-directory>
3550 is the GDB data directory. For more details, see section `Scripting
3551 GDB using Python' in the manual.
3553 ** The GDB Python API now has access to breakpoints, symbols, symbol
3554 tables, program spaces, inferiors, threads and frame's code blocks.
3555 Additionally, GDB Parameters can now be created from the API, and
3556 manipulated via set/show in the CLI.
3558 ** New functions gdb.target_charset, gdb.target_wide_charset,
3559 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3561 ** New exception gdb.GdbError.
3563 ** Pretty-printers are now also looked up in the current program space.
3565 ** Pretty-printers can now be individually enabled and disabled.
3567 ** GDB now looks for names of Python scripts to auto-load in a
3568 special section named `.debug_gdb_scripts', in addition to looking
3569 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3571 * Tracepoint actions were unified with breakpoint commands. In particular,
3572 there are no longer differences in "info break" output for breakpoints and
3573 tracepoints and the "commands" command can be used for both tracepoints and
3574 regular breakpoints.
3578 ARM Symbian arm*-*-symbianelf*
3580 * D language support.
3581 GDB now supports debugging programs written in the D programming
3584 * GDB now supports the extended ptrace interface for PowerPC which is
3585 available since Linux kernel version 2.6.34. This automatically enables
3586 any hardware breakpoints and additional hardware watchpoints available in
3587 the processor. The old ptrace interface exposes just one hardware
3588 watchpoint and no hardware breakpoints.
3590 * GDB is now able to use the Data Value Compare (DVC) register available on
3591 embedded PowerPC processors to implement in hardware simple watchpoint
3592 conditions of the form:
3594 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3596 This works in native GDB running on Linux kernels with the extended ptrace
3597 interface mentioned above.
3599 *** Changes in GDB 7.1
3603 ** Namespace Support
3605 GDB now supports importing of namespaces in C++. This enables the
3606 user to inspect variables from imported namespaces. Support for
3607 namepace aliasing has also been added. So, if a namespace is
3608 aliased in the current scope (e.g. namepace C=A; ) the user can
3609 print variables using the alias (e.g. (gdb) print C::x).
3613 All known bugs relating to the printing of virtual base class were
3614 fixed. It is now possible to call overloaded static methods using a
3619 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3620 and reinterpret_cast<> are now handled by the C++ expression parser.
3624 Xilinx MicroBlaze microblaze-*-*
3629 Xilinx MicroBlaze microblaze
3632 * Multi-program debugging.
3634 GDB now has support for multi-program (a.k.a. multi-executable or
3635 multi-exec) debugging. This allows for debugging multiple inferiors
3636 simultaneously each running a different program under the same GDB
3637 session. See "Debugging Multiple Inferiors and Programs" in the
3638 manual for more information. This implied some user visible changes
3639 in the multi-inferior support. For example, "info inferiors" now
3640 lists inferiors that are not running yet or that have exited
3641 already. See also "New commands" and "New options" below.
3643 * New tracing features
3645 GDB's tracepoint facility now includes several new features:
3647 ** Trace state variables
3649 GDB tracepoints now include support for trace state variables, which
3650 are variables managed by the target agent during a tracing
3651 experiment. They are useful for tracepoints that trigger each
3652 other, so for instance one tracepoint can count hits in a variable,
3653 and then a second tracepoint has a condition that is true when the
3654 count reaches a particular value. Trace state variables share the
3655 $-syntax of GDB convenience variables, and can appear in both
3656 tracepoint actions and condition expressions. Use the "tvariable"
3657 command to create, and "info tvariables" to view; see "Trace State
3658 Variables" in the manual for more detail.
3662 GDB now includes an option for defining fast tracepoints, which
3663 targets may implement more efficiently, such as by installing a jump
3664 into the target agent rather than a trap instruction. The resulting
3665 speedup can be by two orders of magnitude or more, although the
3666 tradeoff is that some program locations on some target architectures
3667 might not allow fast tracepoint installation, for instance if the
3668 instruction to be replaced is shorter than the jump. To request a
3669 fast tracepoint, use the "ftrace" command, with syntax identical to
3670 the regular trace command.
3672 ** Disconnected tracing
3674 It is now possible to detach GDB from the target while it is running
3675 a trace experiment, then reconnect later to see how the experiment
3676 is going. In addition, a new variable disconnected-tracing lets you
3677 tell the target agent whether to continue running a trace if the
3678 connection is lost unexpectedly.
3682 GDB now has the ability to save the trace buffer into a file, and
3683 then use that file as a target, similarly to you can do with
3684 corefiles. You can select trace frames, print data that was
3685 collected in them, and use tstatus to display the state of the
3686 tracing run at the moment that it was saved. To create a trace
3687 file, use "tsave <filename>", and to use it, do "target tfile
3690 ** Circular trace buffer
3692 You can ask the target agent to handle the trace buffer as a
3693 circular buffer, discarding the oldest trace frames to make room for
3694 newer ones, by setting circular-trace-buffer to on. This feature may
3695 not be available for all target agents.
3700 The disassemble command, when invoked with two arguments, now requires
3701 the arguments to be comma-separated.
3704 The info variables command now displays variable definitions. Files
3705 which only declare a variable are not shown.
3708 The source command is now capable of sourcing Python scripts.
3709 This feature is dependent on the debugger being build with Python
3712 Related to this enhancement is also the introduction of a new command
3713 "set script-extension" (see below).
3715 * New commands (for set/show, see "New options" below)
3717 record save [<FILENAME>]
3718 Save a file (in core file format) containing the process record
3719 execution log for replay debugging at a later time.
3721 record restore <FILENAME>
3722 Restore the process record execution log that was saved at an
3723 earlier time, for replay debugging.
3725 add-inferior [-copies <N>] [-exec <FILENAME>]
3728 clone-inferior [-copies <N>] [ID]
3729 Make a new inferior ready to execute the same program another
3730 inferior has loaded.
3735 maint info program-spaces
3736 List the program spaces loaded into GDB.
3738 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3739 show remote interrupt-sequence
3740 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3741 as the sequence to the remote target in order to interrupt the execution.
3742 Ctrl-C is a default. Some system prefers BREAK which is high level of
3743 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3744 Magic SysRq g. It is BREAK signal and character 'g'.
3746 set remote interrupt-on-connect [on | off]
3747 show remote interrupt-on-connect
3748 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3749 remote target when gdb connects to it. This is needed when you debug
3752 set remotebreak [on | off]
3754 Deprecated. Use "set/show remote interrupt-sequence" instead.
3756 tvariable $NAME [ = EXP ]
3757 Create or modify a trace state variable.
3760 List trace state variables and their values.
3762 delete tvariable $NAME ...
3763 Delete one or more trace state variables.
3766 Evaluate the given expressions without collecting anything into the
3767 trace buffer. (Valid in tracepoint actions only.)
3769 ftrace FN / FILE:LINE / *ADDR
3770 Define a fast tracepoint at the given function, line, or address.
3772 * New expression syntax
3774 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3775 GDB now parses 0b101010 identically with 42.
3779 set follow-exec-mode new|same
3780 show follow-exec-mode
3781 Control whether GDB reuses the same inferior across an exec call or
3782 creates a new one. This is useful to be able to restart the old
3783 executable after the inferior having done an exec call.
3785 set default-collect EXPR, ...
3786 show default-collect
3787 Define a list of expressions to be collected at each tracepoint.
3788 This is a useful way to ensure essential items are not overlooked,
3789 such as registers or a critical global variable.
3791 set disconnected-tracing
3792 show disconnected-tracing
3793 If set to 1, the target is instructed to continue tracing if it
3794 loses its connection to GDB. If 0, the target is to stop tracing
3797 set circular-trace-buffer
3798 show circular-trace-buffer
3799 If set to on, the target is instructed to use a circular trace buffer
3800 and discard the oldest trace frames instead of stopping the trace due
3801 to a full trace buffer. If set to off, the trace stops when the buffer
3802 fills up. Some targets may not support this.
3804 set script-extension off|soft|strict
3805 show script-extension
3806 If set to "off", the debugger does not perform any script language
3807 recognition, and all sourced files are assumed to be GDB scripts.
3808 If set to "soft" (the default), files are sourced according to
3809 filename extension, falling back to GDB scripts if the first
3811 If set to "strict", files are sourced according to filename extension.
3813 set ada trust-PAD-over-XVS on|off
3814 show ada trust-PAD-over-XVS
3815 If off, activate a workaround against a bug in the debugging information
3816 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3817 the GCC sources for more information about the GNAT encoding and
3818 PAD types in particular). It is always safe to set this option to
3819 off, but this introduces a slight performance penalty. The default
3822 * Python API Improvements
3824 ** GDB provides the new class gdb.LazyString. This is useful in
3825 some pretty-printing cases. The new method gdb.Value.lazy_string
3826 provides a simple way to create objects of this type.
3828 ** The fields returned by gdb.Type.fields now have an
3829 `is_base_class' attribute.
3831 ** The new method gdb.Type.range returns the range of an array type.
3833 ** The new method gdb.parse_and_eval can be used to parse and
3834 evaluate an expression.
3836 * New remote packets
3839 Define a trace state variable.
3842 Get the current value of a trace state variable.
3845 Set desired tracing behavior upon disconnection.
3848 Set the trace buffer to be linear or circular.
3851 Get data about the tracepoints currently in use.
3855 Process record now works correctly with hardware watchpoints.
3857 Multiple bug fixes have been made to the mips-irix port, making it
3858 much more reliable. In particular:
3859 - Debugging threaded applications is now possible again. Previously,
3860 GDB would hang while starting the program, or while waiting for
3861 the program to stop at a breakpoint.
3862 - Attaching to a running process no longer hangs.
3863 - An error occurring while loading a core file has been fixed.
3864 - Changing the value of the PC register now works again. This fixes
3865 problems observed when using the "jump" command, or when calling
3866 a function from GDB, or even when assigning a new value to $pc.
3867 - With the "finish" and "return" commands, the return value for functions
3868 returning a small array is now correctly printed.
3869 - It is now possible to break on shared library code which gets executed
3870 during a shared library init phase (code executed while executing
3871 their .init section). Previously, the breakpoint would have no effect.
3872 - GDB is now able to backtrace through the signal handler for
3873 non-threaded programs.
3875 PIE (Position Independent Executable) programs debugging is now supported.
3876 This includes debugging execution of PIC (Position Independent Code) shared
3877 libraries although for that, it should be possible to run such libraries as an
3880 *** Changes in GDB 7.0
3882 * GDB now has an interface for JIT compilation. Applications that
3883 dynamically generate code can create symbol files in memory and register
3884 them with GDB. For users, the feature should work transparently, and
3885 for JIT developers, the interface is documented in the GDB manual in the
3886 "JIT Compilation Interface" chapter.
3888 * Tracepoints may now be conditional. The syntax is as for
3889 breakpoints; either an "if" clause appended to the "trace" command,
3890 or the "condition" command is available. GDB sends the condition to
3891 the target for evaluation using the same bytecode format as is used
3892 for tracepoint actions.
3894 * The disassemble command now supports: an optional /r modifier, print the
3895 raw instructions in hex as well as in symbolic form, and an optional /m
3896 modifier to print mixed source+assembly.
3898 * Process record and replay
3900 In a architecture environment that supports ``process record and
3901 replay'', ``process record and replay'' target can record a log of
3902 the process execution, and replay it with both forward and reverse
3905 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3906 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3907 set execution-direction {forward|reverse}, for targets that support
3910 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3911 feature is available with a native GDB running on kernel version
3914 * GDB now has support for multi-byte and wide character sets on the
3915 target. Strings whose character type is wchar_t, char16_t, or
3916 char32_t are now correctly printed. GDB supports wide- and unicode-
3917 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3918 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3919 `printf'. This feature requires iconv to work properly; if your
3920 system does not have a working iconv, GDB can use GNU libiconv. See
3921 the installation instructions for more information.
3923 * GDB now supports automatic retrieval of shared library files from
3924 remote targets. To use this feature, specify a system root that begins
3925 with the `remote:' prefix, either via the `set sysroot' command or via
3926 the `--with-sysroot' configure-time option.
3928 * "info sharedlibrary" now takes an optional regex of libraries to show,
3929 and it now reports if a shared library has no debugging information.
3931 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3932 now complete on file names.
3934 * When completing in expressions, gdb will attempt to limit
3935 completions to allowable structure or union fields, where appropriate.
3936 For instance, consider:
3938 # struct example { int f1; double f2; };
3939 # struct example variable;
3942 If the user types TAB at the end of this command line, the available
3943 completions will be "f1" and "f2".
3945 * Inlined functions are now supported. They show up in backtraces, and
3946 the "step", "next", and "finish" commands handle them automatically.
3948 * GDB now supports the token-splicing (##) and stringification (#)
3949 operators when expanding macros. It also supports variable-arity
3952 * GDB now supports inspecting extra signal information, exported by
3953 the new $_siginfo convenience variable. The feature is currently
3954 implemented on linux ARM, i386 and amd64.
3956 * GDB can now display the VFP floating point registers and NEON vector
3957 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3958 can provide these registers (requires Linux 2.6.30 or later). Remote
3959 and simulator targets may also provide them.
3961 * New remote packets
3964 Search memory for a sequence of bytes.
3967 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3968 operation over reliable transport links. Use of this packet is
3969 controlled by the `set remote noack-packet' command.
3972 Kill the process with the specified process ID. Use this in preference
3973 to `k' when multiprocess protocol extensions are supported.
3976 Obtains additional operating system information
3980 Read or write additional signal information.
3982 * Removed remote protocol undocumented extension
3984 An undocumented extension to the remote protocol's `S' stop reply
3985 packet that permited the stub to pass a process id was removed.
3986 Remote servers should use the `T' stop reply packet instead.
3988 * GDB now supports multiple function calling conventions according to the
3989 DWARF-2 DW_AT_calling_convention function attribute.
3991 * The SH target utilizes the aforementioned change to distinguish between gcc
3992 and Renesas calling convention. It also adds the new CLI commands
3993 `set/show sh calling-convention'.
3995 * GDB can now read compressed debug sections, as produced by GNU gold
3996 with the --compress-debug-sections=zlib flag.
3998 * 64-bit core files are now supported on AIX.
4000 * Thread switching is now supported on Tru64.
4002 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4003 which will be allocated using malloc later in program execution.
4005 * The qXfer:libraries:read remote procotol packet now allows passing a
4006 list of section offsets.
4008 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4009 conditions handling signals delivered during attach or thread creation
4010 have also been fixed.
4012 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4013 From the user's standpoint, all unqualified instances of True and False
4014 are treated as the standard definitions, regardless of context.
4016 * GDB now parses C++ symbol and type names more flexibly. For
4019 template<typename T> class C { };
4022 GDB will now correctly handle all of:
4024 ptype C<char const *>
4025 ptype C<char const*>
4026 ptype C<const char *>
4027 ptype C<const char*>
4029 * New features in the GDB remote stub, gdbserver
4031 - The "--wrapper" command-line argument tells gdbserver to use a
4032 wrapper program to launch programs for debugging.
4034 - On PowerPC and S/390 targets, it is now possible to use a single
4035 gdbserver executable to debug both 32-bit and 64-bit programs.
4036 (This requires gdbserver itself to be built as a 64-bit executable.)
4038 - gdbserver uses the new noack protocol mode for TCP connections to
4039 reduce communications latency, if also supported and enabled in GDB.
4041 - Support for the sparc64-linux-gnu target is now included in
4044 - The amd64-linux build of gdbserver now supports debugging both
4045 32-bit and 64-bit programs.
4047 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4048 now support hardware watchpoints, and will use them automatically
4053 GDB now has support for scripting using Python. Whether this is
4054 available is determined at configure time.
4056 New GDB commands can now be written in Python.
4058 * Ada tasking support
4060 Ada tasks can now be inspected in GDB. The following commands have
4064 Print the list of Ada tasks.
4066 Print detailed information about task number N.
4068 Print the task number of the current task.
4070 Switch the context of debugging to task number N.
4072 * Support for user-defined prefixed commands. The "define" command can
4073 add new commands to existing prefixes, e.g. "target".
4075 * Multi-inferior, multi-process debugging.
4077 GDB now has generalized support for multi-inferior debugging. See
4078 "Debugging Multiple Inferiors" in the manual for more information.
4079 Although availability still depends on target support, the command
4080 set is more uniform now. The GNU/Linux specific multi-forks support
4081 has been migrated to this new framework. This implied some user
4082 visible changes; see "New commands" and also "Removed commands"
4085 * Target descriptions can now describe the target OS ABI. See the
4086 "Target Description Format" section in the user manual for more
4089 * Target descriptions can now describe "compatible" architectures
4090 to indicate that the target can execute applications for a different
4091 architecture in addition to those for the main target architecture.
4092 See the "Target Description Format" section in the user manual for
4095 * Multi-architecture debugging.
4097 GDB now includes general supports for debugging applications on
4098 hybrid systems that use more than one single processor architecture
4099 at the same time. Each such hybrid architecture still requires
4100 specific support to be added. The only hybrid architecture supported
4101 in this version of GDB is the Cell Broadband Engine.
4103 * GDB now supports integrated debugging of Cell/B.E. applications that
4104 use both the PPU and SPU architectures. To enable support for hybrid
4105 Cell/B.E. debugging, you need to configure GDB to support both the
4106 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4107 --enable-targets configure option.
4109 * Non-stop mode debugging.
4111 For some targets, GDB now supports an optional mode of operation in
4112 which you can examine stopped threads while other threads continue
4113 to execute freely. This is referred to as non-stop mode, with the
4114 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4115 section in the user manual for more information.
4117 To be able to support remote non-stop debugging, a remote stub needs
4118 to implement the non-stop mode remote protocol extensions, as
4119 described in the "Remote Non-Stop" section of the user manual. The
4120 GDB remote stub, gdbserver, has been adjusted to support these
4121 extensions on linux targets.
4123 * New commands (for set/show, see "New options" below)
4125 catch syscall [NAME(S) | NUMBER(S)]
4126 Catch system calls. Arguments, which should be names of system
4127 calls or their numbers, mean catch only those syscalls. Without
4128 arguments, every syscall will be caught. When the inferior issues
4129 any of the specified syscalls, GDB will stop and announce the system
4130 call, both when it is called and when its call returns. This
4131 feature is currently available with a native GDB running on the
4132 Linux Kernel, under the following architectures: x86, x86_64,
4133 PowerPC and PowerPC64.
4135 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4137 Search memory for a sequence of bytes.
4139 maint set python print-stack
4140 maint show python print-stack
4141 Show a stack trace when an error is encountered in a Python script.
4144 Invoke CODE by passing it to the Python interpreter.
4149 These allow macros to be defined, undefined, and listed
4153 Show operating system information about processes.
4156 List the inferiors currently under GDB's control.
4159 Switch focus to inferior number NUM.
4162 Detach from inferior number NUM.
4165 Kill inferior number NUM.
4169 set spu stop-on-load
4170 show spu stop-on-load
4171 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4173 set spu auto-flush-cache
4174 show spu auto-flush-cache
4175 Control whether to automatically flush the software-managed cache
4176 during Cell/B.E. debugging.
4178 set sh calling-convention
4179 show sh calling-convention
4180 Control the calling convention used when calling SH target functions.
4183 show debug timestamp
4184 Control display of timestamps with GDB debugging output.
4186 set disassemble-next-line
4187 show disassemble-next-line
4188 Control display of disassembled source lines or instructions when
4191 set remote noack-packet
4192 show remote noack-packet
4193 Set/show the use of remote protocol QStartNoAckMode packet. See above
4194 under "New remote packets."
4196 set remote query-attached-packet
4197 show remote query-attached-packet
4198 Control use of remote protocol `qAttached' (query-attached) packet.
4200 set remote read-siginfo-object
4201 show remote read-siginfo-object
4202 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4205 set remote write-siginfo-object
4206 show remote write-siginfo-object
4207 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4210 set remote reverse-continue
4211 show remote reverse-continue
4212 Control use of remote protocol 'bc' (reverse-continue) packet.
4214 set remote reverse-step
4215 show remote reverse-step
4216 Control use of remote protocol 'bs' (reverse-step) packet.
4218 set displaced-stepping
4219 show displaced-stepping
4220 Control displaced stepping mode. Displaced stepping is a way to
4221 single-step over breakpoints without removing them from the debuggee.
4222 Also known as "out-of-line single-stepping".
4225 show debug displaced
4226 Control display of debugging info for displaced stepping.
4228 maint set internal-error
4229 maint show internal-error
4230 Control what GDB does when an internal error is detected.
4232 maint set internal-warning
4233 maint show internal-warning
4234 Control what GDB does when an internal warning is detected.
4239 Use a wrapper program to launch programs for debugging.
4241 set multiple-symbols (all|ask|cancel)
4242 show multiple-symbols
4243 The value of this variable can be changed to adjust the debugger behavior
4244 when an expression or a breakpoint location contains an ambiguous symbol
4245 name (an overloaded function name, for instance).
4247 set breakpoint always-inserted
4248 show breakpoint always-inserted
4249 Keep breakpoints always inserted in the target, as opposed to inserting
4250 them when resuming the target, and removing them when the target stops.
4251 This option can improve debugger performance on slow remote targets.
4253 set arm fallback-mode (arm|thumb|auto)
4254 show arm fallback-mode
4255 set arm force-mode (arm|thumb|auto)
4257 These commands control how ARM GDB determines whether instructions
4258 are ARM or Thumb. The default for both settings is auto, which uses
4259 the current CPSR value for instructions without symbols; previous
4260 versions of GDB behaved as if "set arm fallback-mode arm".
4262 set disable-randomization
4263 show disable-randomization
4264 Standalone programs run with the virtual address space randomization enabled
4265 by default on some platforms. This option keeps the addresses stable across
4266 multiple debugging sessions.
4270 Control whether other threads are stopped or not when some thread hits
4275 Requests that asynchronous execution is enabled in the target, if available.
4276 In this case, it's possible to resume target in the background, and interact
4277 with GDB while the target is running. "show target-async" displays the
4278 current state of asynchronous execution of the target.
4280 set target-wide-charset
4281 show target-wide-charset
4282 The target-wide-charset is the name of the character set that GDB
4283 uses when printing characters whose type is wchar_t.
4285 set tcp auto-retry (on|off)
4287 set tcp connect-timeout
4288 show tcp connect-timeout
4289 These commands allow GDB to retry failed TCP connections to a remote stub
4290 with a specified timeout period; this is useful if the stub is launched
4291 in parallel with GDB but may not be ready to accept connections immediately.
4293 set libthread-db-search-path
4294 show libthread-db-search-path
4295 Control list of directories which GDB will search for appropriate
4298 set schedule-multiple (on|off)
4299 show schedule-multiple
4300 Allow GDB to resume all threads of all processes or only threads of
4301 the current process.
4305 Use more aggressive caching for accesses to the stack. This improves
4306 performance of remote debugging (particularly backtraces) without
4307 affecting correctness.
4309 set interactive-mode (on|off|auto)
4310 show interactive-mode
4311 Control whether GDB runs in interactive mode (on) or not (off).
4312 When in interactive mode, GDB waits for the user to answer all
4313 queries. Otherwise, GDB does not wait and assumes the default
4314 answer. When set to auto (the default), GDB determines which
4315 mode to use based on the stdin settings.
4320 For program forks, this is replaced by the new more generic `info
4321 inferiors' command. To list checkpoints, you can still use the
4322 `info checkpoints' command, which was an alias for the `info forks'
4326 Replaced by the new `inferior' command. To switch between
4327 checkpoints, you can still use the `restart' command, which was an
4328 alias for the `fork' command.
4331 This is removed, since some targets don't have a notion of
4332 processes. To switch between processes, you can still use the
4333 `inferior' command using GDB's own inferior number.
4336 For program forks, this is replaced by the new more generic `kill
4337 inferior' command. To delete a checkpoint, you can still use the
4338 `delete checkpoint' command, which was an alias for the `delete
4342 For program forks, this is replaced by the new more generic `detach
4343 inferior' command. To detach a checkpoint, you can still use the
4344 `detach checkpoint' command, which was an alias for the `detach
4347 * New native configurations
4349 x86/x86_64 Darwin i[34567]86-*-darwin*
4351 x86_64 MinGW x86_64-*-mingw*
4355 Lattice Mico32 lm32-*
4356 x86 DICOS i[34567]86-*-dicos*
4357 x86_64 DICOS x86_64-*-dicos*
4360 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4361 (mingw32ce) debugging.
4367 These commands were actually not implemented on any target.
4369 *** Changes in GDB 6.8
4371 * New native configurations
4373 NetBSD/hppa hppa*-*netbsd*
4374 Xtensa GNU/Linux xtensa*-*-linux*
4378 NetBSD/hppa hppa*-*-netbsd*
4379 Xtensa GNU/Lunux xtensa*-*-linux*
4381 * Change in command line behavior -- corefiles vs. process ids.
4383 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4384 attaching to process NUMBER fails, GDB no longer attempts to open a
4385 core file named NUMBER. Attaching to a program using the -c option
4386 is no longer supported. Instead, use the '-p' or '--pid' options.
4388 * GDB can now be built as a native debugger for debugging Windows x86
4389 (mingw32) Portable Executable (PE) programs.
4391 * Pending breakpoints no longer change their number when their address
4394 * GDB now supports breakpoints with multiple locations,
4395 including breakpoints on C++ constructors, inside C++ templates,
4396 and in inlined functions.
4398 * GDB's ability to debug optimized code has been improved. GDB more
4399 accurately identifies function bodies and lexical blocks that occupy
4400 more than one contiguous range of addresses.
4402 * Target descriptions can now describe registers for PowerPC.
4404 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4405 registers on PowerPC targets.
4407 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4408 targets even when the libthread_db library is not available.
4410 * The GDB remote stub, gdbserver, now supports the new file transfer
4411 commands (remote put, remote get, and remote delete).
4413 * The GDB remote stub, gdbserver, now supports run and attach in
4414 extended-remote mode.
4416 * hppa*64*-*-hpux11* target broken
4417 The debugger is unable to start a program and fails with the following
4418 error: "Error trying to get information about dynamic linker".
4419 The gdb-6.7 release is also affected.
4421 * GDB now supports the --enable-targets= configure option to allow
4422 building a single GDB executable that supports multiple remote
4423 target architectures.
4425 * GDB now supports debugging C and C++ programs which use the
4426 Decimal Floating Point extension. In addition, the PowerPC target
4427 now has a set of pseudo-registers to inspect decimal float values
4428 stored in two consecutive float registers.
4430 * The -break-insert MI command can optionally create pending
4433 * Improved support for debugging Ada
4434 Many improvements to the Ada language support have been made. These
4436 - Better support for Ada2005 interface types
4437 - Improved handling of arrays and slices in general
4438 - Better support for Taft-amendment types
4439 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4441 - Improved command completion in Ada
4444 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4449 set print frame-arguments (all|scalars|none)
4450 show print frame-arguments
4451 The value of this variable can be changed to control which argument
4452 values should be printed by the debugger when displaying a frame.
4457 Transfer files to and from a remote target, and delete remote files.
4464 Transfer files to and from a remote target, and delete remote files.
4466 * New remote packets
4473 Open, close, read, write, and delete files on the remote system.
4476 Attach to an existing process on the remote system, in extended-remote
4480 Run a new process on the remote system, in extended-remote mode.
4482 *** Changes in GDB 6.7
4484 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4485 bfd, libiberty and opcodes, as revealed by static analysis donated by
4486 Coverity, Inc. (http://scan.coverity.com).
4488 * When looking up multiply-defined global symbols, GDB will now prefer the
4489 symbol definition in the current shared library if it was built using the
4490 -Bsymbolic linker option.
4492 * When the Text User Interface (TUI) is not configured, GDB will now
4493 recognize the -tui command-line option and print a message that the TUI
4496 * The GDB remote stub, gdbserver, now has lower overhead for high
4497 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4499 * GDB for MIPS targets now autodetects whether a remote target provides
4500 32-bit or 64-bit register values.
4502 * Support for C++ member pointers has been improved.
4504 * GDB now understands XML target descriptions, which specify the
4505 target's overall architecture. GDB can read a description from
4506 a local file or over the remote serial protocol.
4508 * Vectors of single-byte data use a new integer type which is not
4509 automatically displayed as character or string data.
4511 * The /s format now works with the print command. It displays
4512 arrays of single-byte integers and pointers to single-byte integers
4515 * Target descriptions can now describe target-specific registers,
4516 for architectures which have implemented the support (currently
4517 only ARM, M68K, and MIPS).
4519 * GDB and the GDB remote stub, gdbserver, now support the XScale
4522 * The GDB remote stub, gdbserver, has been updated to support
4523 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4524 has been rewritten to use the standard GDB remote protocol.
4526 * GDB can now step into C++ functions which are called through thunks.
4528 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4530 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4531 layout. It also supports a TextSeg= and DataSeg= response when only
4532 segment base addresses (rather than offsets) are available.
4534 * The /i format now outputs any trailing branch delay slot instructions
4535 immediately following the last instruction within the count specified.
4537 * The GDB remote protocol "T" stop reply packet now supports a
4538 "library" response. Combined with the new "qXfer:libraries:read"
4539 packet, this response allows GDB to debug shared libraries on targets
4540 where the operating system manages the list of loaded libraries (e.g.
4541 Windows and SymbianOS).
4543 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4544 (DLLs) on Windows and Windows CE targets.
4546 * GDB now supports a faster verification that a .debug file matches its binary
4547 according to its build-id signature, if the signature is present.
4553 Enable or disable hardware flow control (RTS/CTS) on the serial port
4554 when debugging using remote targets.
4556 set mem inaccessible-by-default
4557 show mem inaccessible-by-default
4558 If the target supplies a memory map, for instance via the remote
4559 protocol's "qXfer:memory-map:read" packet, setting this variable
4560 prevents GDB from accessing memory outside the memory map. This
4561 is useful for targets with memory mapped registers or which react
4562 badly to accesses of unmapped address space.
4564 set breakpoint auto-hw
4565 show breakpoint auto-hw
4566 If the target supplies a memory map, for instance via the remote
4567 protocol's "qXfer:memory-map:read" packet, setting this variable
4568 lets GDB use hardware breakpoints automatically for memory regions
4569 where it can not use software breakpoints. This covers both the
4570 "break" command and internal breakpoints used for other commands
4571 including "next" and "finish".
4574 catch exception unhandled
4575 Stop the program execution when Ada exceptions are raised.
4578 Stop the program execution when an Ada assertion failed.
4582 Set an alternate system root for target files. This is a more
4583 general version of "set solib-absolute-prefix", which is now
4584 an alias to "set sysroot".
4587 Provide extended SPU facility status information. This set of
4588 commands is available only when debugging the Cell/B.E. SPU
4591 * New native configurations
4593 OpenBSD/sh sh*-*openbsd*
4596 unset tdesc filename
4598 Use the specified local file as an XML target description, and do
4599 not query the target for its built-in description.
4603 OpenBSD/sh sh*-*-openbsd*
4604 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4605 Toshiba Media Processor mep-elf
4607 * New remote packets
4610 Ignore the specified signals; pass them directly to the debugged program
4611 without stopping other threads or reporting them to GDB.
4613 qXfer:features:read:
4614 Read an XML target description from the target, which describes its
4619 Read or write contents of an spufs file on the target system. These
4620 packets are available only on the Cell/B.E. SPU architecture.
4622 qXfer:libraries:read:
4623 Report the loaded shared libraries. Combined with new "T" packet
4624 response, this packet allows GDB to debug shared libraries on
4625 targets where the operating system manages the list of loaded
4626 libraries (e.g. Windows and SymbianOS).
4630 Support for these obsolete configurations has been removed.
4638 i[34567]86-*-lynxos*
4639 i[34567]86-*-netware*
4640 i[34567]86-*-sco3.2v5*
4641 i[34567]86-*-sco3.2v4*
4643 i[34567]86-*-sysv4.2*
4646 i[34567]86-*-unixware2*
4647 i[34567]86-*-unixware*
4656 * Other removed features
4663 Various m68k-only ROM monitors.
4670 Various Renesas ROM monitors and debugging interfaces for SH and
4675 Support for a Macraigor serial interface to on-chip debugging.
4676 GDB does not directly support the newer parallel or USB
4681 A debug information format. The predecessor to DWARF 2 and
4682 DWARF 3, which are still supported.
4684 Support for the HP aCC compiler on HP-UX/PA-RISC
4686 SOM-encapsulated symbolic debugging information, automatic
4687 invocation of pxdb, and the aCC custom C++ ABI. This does not
4688 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4689 with aCC can still be debugged on an assembly level.
4691 MIPS ".pdr" sections
4693 A MIPS-specific format used to describe stack frame layout
4694 in debugging information.
4698 GDB could work with an older version of Guile to debug
4699 the interpreter and Scheme programs running in it.
4701 set mips stack-arg-size
4702 set mips saved-gpreg-size
4704 Use "set mips abi" to control parameter passing for MIPS.
4706 *** Changes in GDB 6.6
4711 Cell Broadband Engine SPU spu-elf
4713 * GDB can now be configured as a cross-debugger targeting native Windows
4714 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4715 running on a Windows system over TCP/IP to debug Windows programs.
4717 * The GDB remote stub, gdbserver, has been updated to support Windows and
4718 Cygwin debugging. Both single-threaded and multi-threaded programs are
4721 * The "set trust-readonly-sections" command works again. This command was
4722 broken in GDB 6.3, 6.4, and 6.5.
4724 * The "load" command now supports writing to flash memory, if the remote
4725 stub provides the required support.
4727 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4728 longer requires symbolic debug information (e.g. DWARF-2).
4733 unset substitute-path
4734 show substitute-path
4735 Manage a list of substitution rules that GDB uses to rewrite the name
4736 of the directories where the sources are located. This can be useful
4737 for instance when the sources were moved to a different location
4738 between compilation and debugging.
4742 Print each CLI command as it is executed. Each command is prefixed with
4743 a number of `+' symbols representing the nesting depth.
4744 The source command now has a `-v' option to enable the same feature.
4748 The ARM Demon monitor support (RDP protocol, "target rdp").
4750 Kernel Object Display, an embedded debugging feature which only worked with
4751 an obsolete version of Cisco IOS.
4753 The 'set download-write-size' and 'show download-write-size' commands.
4755 * New remote packets
4758 Tell a stub about GDB client features, and request remote target features.
4759 The first feature implemented is PacketSize, which allows the target to
4760 specify the size of packets it can handle - to minimize the number of
4761 packets required and improve performance when connected to a remote
4765 Fetch an OS auxilliary vector from the remote stub. This packet is a
4766 more efficient replacement for qPart:auxv:read.
4768 qXfer:memory-map:read:
4769 Fetch a memory map from the remote stub, including information about
4770 RAM, ROM, and flash memory devices.
4775 Erase and program a flash memory device.
4777 * Removed remote packets
4780 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4781 used it, and only gdbserver implemented it.
4783 *** Changes in GDB 6.5
4787 Renesas M32C/M16C m32c-elf
4789 Morpho Technologies ms1 ms1-elf
4793 init-if-undefined Initialize a convenience variable, but
4794 only if it doesn't already have a value.
4796 The following commands are presently only implemented for native GNU/Linux:
4798 checkpoint Save a snapshot of the program state.
4800 restart <n> Return the program state to a
4801 previously saved state.
4803 info checkpoints List currently saved checkpoints.
4805 delete-checkpoint <n> Delete a previously saved checkpoint.
4807 set|show detach-on-fork Tell gdb whether to detach from a newly
4808 forked process, or to keep debugging it.
4810 info forks List forks of the user program that
4811 are available to be debugged.
4813 fork <n> Switch to debugging one of several
4814 forks of the user program that are
4815 available to be debugged.
4817 delete-fork <n> Delete a fork from the list of forks
4818 that are available to be debugged (and
4819 kill the forked process).
4821 detach-fork <n> Delete a fork from the list of forks
4822 that are available to be debugged (and
4823 allow the process to continue).
4827 Morpho Technologies ms2 ms1-elf
4829 * Improved Windows host support
4831 GDB now builds as a cross debugger hosted on i686-mingw32, including
4832 native console support, and remote communications using either
4833 network sockets or serial ports.
4835 * Improved Modula-2 language support
4837 GDB can now print most types in the Modula-2 syntax. This includes:
4838 basic types, set types, record types, enumerated types, range types,
4839 pointer types and ARRAY types. Procedure var parameters are correctly
4840 printed and hexadecimal addresses and character constants are also
4841 written in the Modula-2 syntax. Best results can be obtained by using
4842 GNU Modula-2 together with the -gdwarf-2 command line option.
4846 The ARM rdi-share module.
4848 The Netware NLM debug server.
4850 *** Changes in GDB 6.4
4852 * New native configurations
4854 OpenBSD/arm arm*-*-openbsd*
4855 OpenBSD/mips64 mips64-*-openbsd*
4859 Morpho Technologies ms1 ms1-elf
4861 * New command line options
4863 --batch-silent As for --batch, but totally silent.
4864 --return-child-result The debugger will exist with the same value
4865 the child (debugged) program exited with.
4866 --eval-command COMMAND, -ex COMMAND
4867 Execute a single GDB CLI command. This may be
4868 specified multiple times and in conjunction
4869 with the --command (-x) option.
4871 * Deprecated commands removed
4873 The following commands, that were deprecated in 2000, have been
4877 set|show arm disassembly-flavor set|show arm disassembler
4878 othernames set arm disassembler
4879 set|show remotedebug set|show debug remote
4880 set|show archdebug set|show debug arch
4881 set|show eventdebug set|show debug event
4884 * New BSD user-level threads support
4886 It is now possible to debug programs using the user-level threads
4887 library on OpenBSD and FreeBSD. Currently supported (target)
4890 FreeBSD/amd64 x86_64-*-freebsd*
4891 FreeBSD/i386 i386-*-freebsd*
4892 OpenBSD/i386 i386-*-openbsd*
4894 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4895 are not yet supported.
4897 * New support for Matsushita MN10300 w/sim added
4898 (Work in progress). mn10300-elf.
4900 * REMOVED configurations and files
4902 VxWorks and the XDR protocol *-*-vxworks
4903 Motorola MCORE mcore-*-*
4904 National Semiconductor NS32000 ns32k-*-*
4906 * New "set print array-indexes" command
4908 After turning this setting "on", GDB prints the index of each element
4909 when displaying arrays. The default is "off" to preserve the previous
4912 * VAX floating point support
4914 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4916 * User-defined command support
4918 In addition to using $arg0..$arg9 for argument passing, it is now possible
4919 to use $argc to determine now many arguments have been passed. See the
4920 section on user-defined commands in the user manual for more information.
4922 *** Changes in GDB 6.3:
4924 * New command line option
4926 GDB now accepts -l followed by a number to set the timeout for remote
4929 * GDB works with GCC -feliminate-dwarf2-dups
4931 GDB now supports a more compact representation of DWARF-2 debug
4932 information using DW_FORM_ref_addr references. These are produced
4933 by GCC with the option -feliminate-dwarf2-dups and also by some
4934 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4935 to use -feliminate-dwarf2-dups.
4937 * Internationalization
4939 When supported by the host system, GDB will be built with
4940 internationalization (libintl). The task of marking up the sources is
4941 continued, we're looking forward to our first translation.
4945 Initial support for debugging programs compiled with the GNAT
4946 implementation of the Ada programming language has been integrated
4947 into GDB. In this release, support is limited to expression evaluation.
4949 * New native configurations
4951 GNU/Linux/m32r m32r-*-linux-gnu
4955 GDB's remote protocol now includes support for the 'p' packet. This
4956 packet is used to fetch individual registers from a remote inferior.
4958 * END-OF-LIFE registers[] compatibility module
4960 GDB's internal register infrastructure has been completely rewritten.
4961 The new infrastructure making possible the implementation of key new
4962 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4965 GDB 6.3 will be the last release to include the the registers[]
4966 compatibility module that allowed out-of-date configurations to
4967 continue to work. This change directly impacts the following
4977 powerpc bdm protocol
4979 Unless there is activity to revive these configurations, they will be
4980 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4982 * OBSOLETE configurations and files
4984 Configurations that have been declared obsolete in this release have
4985 been commented out. Unless there is activity to revive these
4986 configurations, the next release of GDB will have their sources
4987 permanently REMOVED.
4996 *** Changes in GDB 6.2.1:
4998 * MIPS `break main; run' gave an heuristic-fence-post warning
5000 When attempting to run even a simple program, a warning about
5001 heuristic-fence-post being hit would be reported. This problem has
5004 * MIPS IRIX 'long double' crashed GDB
5006 When examining a long double variable, GDB would get a segmentation
5007 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5008 IRIX long double values).
5012 A bug in the VAX stack code was causing problems with the "next"
5013 command. This problem has been fixed.
5015 *** Changes in GDB 6.2:
5017 * Fix for ``many threads''
5019 On GNU/Linux systems that use the NPTL threads library, a program
5020 rapidly creating and deleting threads would confuse GDB leading to the
5023 ptrace: No such process.
5024 thread_db_get_info: cannot get thread info: generic error
5026 This problem has been fixed.
5028 * "-async" and "-noasync" options removed.
5030 Support for the broken "-noasync" option has been removed (it caused
5033 * New ``start'' command.
5035 This command runs the program until the begining of the main procedure.
5037 * New BSD Kernel Data Access Library (libkvm) interface
5039 Using ``target kvm'' it is now possible to debug kernel core dumps and
5040 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5041 platforms. Currently supported (native-only) configurations are:
5043 FreeBSD/amd64 x86_64-*-freebsd*
5044 FreeBSD/i386 i?86-*-freebsd*
5045 NetBSD/i386 i?86-*-netbsd*
5046 NetBSD/m68k m68*-*-netbsd*
5047 NetBSD/sparc sparc-*-netbsd*
5048 OpenBSD/amd64 x86_64-*-openbsd*
5049 OpenBSD/i386 i?86-*-openbsd*
5050 OpenBSD/m68k m68*-openbsd*
5051 OpenBSD/sparc sparc-*-openbsd*
5053 * Signal trampoline code overhauled
5055 Many generic problems with GDB's signal handling code have been fixed.
5056 These include: backtraces through non-contiguous stacks; recognition
5057 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5058 call; backtrace through a signal trampoline; step into and out of
5059 signal handlers; and single-stepping in the signal trampoline.
5061 Please note that kernel bugs are a limiting factor here. These
5062 features have been shown to work on an s390 GNU/Linux system that
5063 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5065 * Cygwin support for DWARF 2 added.
5067 * New native configurations
5069 GNU/Linux/hppa hppa*-*-linux*
5070 OpenBSD/hppa hppa*-*-openbsd*
5071 OpenBSD/m68k m68*-*-openbsd*
5072 OpenBSD/m88k m88*-*-openbsd*
5073 OpenBSD/powerpc powerpc-*-openbsd*
5074 NetBSD/vax vax-*-netbsd*
5075 OpenBSD/vax vax-*-openbsd*
5077 * END-OF-LIFE frame compatibility module
5079 GDB's internal frame infrastructure has been completely rewritten.
5080 The new infrastructure making it possible to support key new features
5081 including DWARF 2 Call Frame Information. To aid in the task of
5082 migrating old configurations to this new infrastructure, a
5083 compatibility module, that allowed old configurations to continue to
5084 work, was also included.
5086 GDB 6.2 will be the last release to include this frame compatibility
5087 module. This change directly impacts the following configurations:
5097 Unless there is activity to revive these configurations, they will be
5098 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5100 * REMOVED configurations and files
5102 Sun 3, running SunOS 3 m68*-*-sunos3*
5103 Sun 3, running SunOS 4 m68*-*-sunos4*
5104 Sun 2, running SunOS 3 m68000-*-sunos3*
5105 Sun 2, running SunOS 4 m68000-*-sunos4*
5106 Motorola 680x0 running LynxOS m68*-*-lynxos*
5107 AT&T 3b1/Unix pc m68*-att-*
5108 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5109 decstation mips-dec-* mips-little-*
5110 riscos mips-*-riscos* mips-*-sysv*
5111 sonymips mips-sony-*
5112 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5114 *** Changes in GDB 6.1.1:
5116 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5118 The TUI (Text-mode User Interface) is now built as part of a default
5119 GDB configuration. It is enabled by either selecting the TUI with the
5120 command line option "-i=tui" or by running the separate "gdbtui"
5121 program. For more information on the TUI, see the manual "Debugging
5124 * Pending breakpoint support (also included in GDB 6.1)
5126 Support has been added to allow you to specify breakpoints in shared
5127 libraries that have not yet been loaded. If a breakpoint location
5128 cannot be found, and the "breakpoint pending" option is set to auto,
5129 GDB queries you if you wish to make the breakpoint pending on a future
5130 shared-library load. If and when GDB resolves the breakpoint symbol,
5131 the pending breakpoint is removed as one or more regular breakpoints
5134 Pending breakpoints are very useful for GCJ Java debugging.
5136 * Fixed ISO-C build problems
5138 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5139 non ISO-C code that stopped them being built using a more strict ISO-C
5140 compiler (e.g., IBM's C compiler).
5142 * Fixed build problem on IRIX 5
5144 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5145 wasn't able to compile compile on an IRIX 5 system.
5147 * Added execute permission to gdb/gdbserver/configure
5149 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5150 permission. This bug would cause configure to fail on a number of
5151 systems (Solaris, IRIX). Ref: server/519.
5153 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5155 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5156 has been updated to use constant array sizes.
5158 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5160 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5161 its generated DWARF Call Frame Info. This encoding was causing GDB to
5162 panic, that panic has been fixed. Ref: gdb/1628.
5164 * Fixed a problem when examining parameters in shared library code.
5166 When examining parameters in optimized shared library code generated
5167 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5168 not available''. GDB now correctly displays the variable's value.
5170 *** Changes in GDB 6.1:
5172 * Removed --with-mmalloc
5174 Support for the mmalloc memory manager has been removed, as it
5175 conflicted with the internal gdb byte cache.
5177 * Changes in AMD64 configurations
5179 The AMD64 target now includes the %cs and %ss registers. As a result
5180 the AMD64 remote protocol has changed; this affects the floating-point
5181 and SSE registers. If you rely on those registers for your debugging,
5182 you should upgrade gdbserver on the remote side.
5184 * Revised SPARC target
5186 The SPARC target has been completely revised, incorporating the
5187 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5188 support for LynxOS and SunOS 4 has been dropped. Calling functions
5189 from within GDB on operating systems with a non-executable stack
5190 (Solaris, OpenBSD) now works.
5194 GDB has a new C++ demangler which does a better job on the mangled
5195 names generated by current versions of g++. It also runs faster, so
5196 with this and other changes gdb should now start faster on large C++
5199 * DWARF 2 Location Expressions
5201 GDB support for location expressions has been extended to support function
5202 arguments and frame bases. Older versions of GDB could crash when they
5205 * C++ nested types and namespaces
5207 GDB's support for nested types and namespaces in C++ has been
5208 improved, especially if you use the DWARF 2 debugging format. (This
5209 is the default for recent versions of GCC on most platforms.)
5210 Specifically, if you have a class "Inner" defined within a class or
5211 namespace "Outer", then GDB realizes that the class's name is
5212 "Outer::Inner", not simply "Inner". This should greatly reduce the
5213 frequency of complaints about not finding RTTI symbols. In addition,
5214 if you are stopped at inside of a function defined within a namespace,
5215 GDB modifies its name lookup accordingly.
5217 * New native configurations
5219 NetBSD/amd64 x86_64-*-netbsd*
5220 OpenBSD/amd64 x86_64-*-openbsd*
5221 OpenBSD/alpha alpha*-*-openbsd*
5222 OpenBSD/sparc sparc-*-openbsd*
5223 OpenBSD/sparc64 sparc64-*-openbsd*
5225 * New debugging protocols
5227 M32R with SDI protocol m32r-*-elf*
5229 * "set prompt-escape-char" command deleted.
5231 The command "set prompt-escape-char" has been deleted. This command,
5232 and its very obscure effet on GDB's prompt, was never documented,
5233 tested, nor mentioned in the NEWS file.
5235 * OBSOLETE configurations and files
5237 Configurations that have been declared obsolete in this release have
5238 been commented out. Unless there is activity to revive these
5239 configurations, the next release of GDB will have their sources
5240 permanently REMOVED.
5242 Sun 3, running SunOS 3 m68*-*-sunos3*
5243 Sun 3, running SunOS 4 m68*-*-sunos4*
5244 Sun 2, running SunOS 3 m68000-*-sunos3*
5245 Sun 2, running SunOS 4 m68000-*-sunos4*
5246 Motorola 680x0 running LynxOS m68*-*-lynxos*
5247 AT&T 3b1/Unix pc m68*-att-*
5248 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5249 decstation mips-dec-* mips-little-*
5250 riscos mips-*-riscos* mips-*-sysv*
5251 sonymips mips-sony-*
5252 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5254 * REMOVED configurations and files
5256 SGI Irix-4.x mips-sgi-irix4 or iris4
5257 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5258 Z8000 simulator z8k-zilog-none or z8ksim
5259 Matsushita MN10200 w/simulator mn10200-*-*
5260 H8/500 simulator h8500-hitachi-hms or h8500hms
5261 HP/PA running BSD hppa*-*-bsd*
5262 HP/PA running OSF/1 hppa*-*-osf*
5263 HP/PA Pro target hppa*-*-pro*
5264 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5265 386BSD i[3456]86-*-bsd*
5266 Sequent family i[3456]86-sequent-sysv4*
5267 i[3456]86-sequent-sysv*
5268 i[3456]86-sequent-bsd*
5269 SPARC running LynxOS sparc-*-lynxos*
5270 SPARC running SunOS 4 sparc-*-sunos4*
5271 Tsqware Sparclet sparclet-*-*
5272 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5274 *** Changes in GDB 6.0:
5278 Support for debugging the Objective-C programming language has been
5279 integrated into GDB.
5281 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5283 DWARF 2's Call Frame Information makes available compiler generated
5284 information that more exactly describes the program's run-time stack.
5285 By using this information, GDB is able to provide more robust stack
5288 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5289 have been updated to use a new backtrace mechanism which includes
5290 DWARF 2 CFI support.
5294 GDB's remote protocol has been extended to include support for hosted
5295 file I/O (where the remote target uses GDB's file system). See GDB's
5296 remote protocol documentation for details.
5298 * All targets using the new architecture framework.
5300 All of GDB's targets have been updated to use the new internal
5301 architecture framework. The way is now open for future GDB releases
5302 to include cross-architecture native debugging support (i386 on amd64,
5305 * GNU/Linux's Thread Local Storage (TLS)
5307 GDB now includes support for for the GNU/Linux implementation of
5308 per-thread variables.
5310 * GNU/Linux's Native POSIX Thread Library (NPTL)
5312 GDB's thread code has been updated to work with either the new
5313 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5315 * Separate debug info.
5317 GDB, in conjunction with BINUTILS, now supports a mechanism for
5318 automatically loading debug information from a separate file. Instead
5319 of shipping full debug and non-debug versions of system libraries,
5320 system integrators can now instead ship just the stripped libraries
5321 and optional debug files.
5323 * DWARF 2 Location Expressions
5325 DWARF 2 Location Expressions allow the compiler to more completely
5326 describe the location of variables (even in optimized code) to the
5329 GDB now includes preliminary support for location expressions (support
5330 for DW_OP_piece is still missing).
5334 A number of long standing bugs that caused GDB to die while starting a
5335 Java application have been fixed. GDB's Java support is now
5336 considered "useable".
5338 * GNU/Linux support for fork, vfork, and exec.
5340 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5341 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5344 * GDB supports logging output to a file
5346 There are two new commands, "set logging" and "show logging", which can be
5347 used to capture GDB's output to a file.
5349 * The meaning of "detach" has changed for gdbserver
5351 The "detach" command will now resume the application, as documented. To
5352 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5355 * d10v, m68hc11 `regs' command deprecated
5357 The `info registers' command has been updated so that it displays the
5358 registers using a format identical to the old `regs' command.
5362 A new command, "maint set profile on/off", has been added. This command can
5363 be used to enable or disable profiling while running GDB, to profile a
5364 session or a set of commands. In addition there is a new configure switch,
5365 "--enable-profiling", which will cause GDB to be compiled with profiling
5366 data, for more informative profiling results.
5368 * Default MI syntax changed to "mi2".
5370 The default MI (machine interface) syntax, enabled by the command line
5371 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5372 "mi1", can be enabled by specifying the option "-i=mi1".
5374 Support for the original "mi0" syntax (included in GDB 5.0) has been
5377 Fix for gdb/192: removed extraneous space when displaying frame level.
5378 Fix for gdb/672: update changelist is now output in mi list format.
5379 Fix for gdb/702: a -var-assign that updates the value now shows up
5380 in a subsequent -var-update.
5382 * New native configurations.
5384 FreeBSD/amd64 x86_64-*-freebsd*
5386 * Multi-arched targets.
5388 HP/PA HPUX11 hppa*-*-hpux*
5389 Renesas M32R/D w/simulator m32r-*-elf*
5391 * OBSOLETE configurations and files
5393 Configurations that have been declared obsolete in this release have
5394 been commented out. Unless there is activity to revive these
5395 configurations, the next release of GDB will have their sources
5396 permanently REMOVED.
5398 Z8000 simulator z8k-zilog-none or z8ksim
5399 Matsushita MN10200 w/simulator mn10200-*-*
5400 H8/500 simulator h8500-hitachi-hms or h8500hms
5401 HP/PA running BSD hppa*-*-bsd*
5402 HP/PA running OSF/1 hppa*-*-osf*
5403 HP/PA Pro target hppa*-*-pro*
5404 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5405 Sequent family i[3456]86-sequent-sysv4*
5406 i[3456]86-sequent-sysv*
5407 i[3456]86-sequent-bsd*
5408 Tsqware Sparclet sparclet-*-*
5409 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5411 * REMOVED configurations and files
5414 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5415 IBM AIX PS/2 i[3456]86-*-aix
5416 i386 running Mach 3.0 i[3456]86-*-mach3*
5417 i386 running Mach i[3456]86-*-mach*
5418 i386 running OSF/1 i[3456]86-*osf1mk*
5419 HP/Apollo 68k Family m68*-apollo*-sysv*,
5421 m68*-hp-bsd*, m68*-hp-hpux*
5422 Argonaut Risc Chip (ARC) arc-*-*
5423 Mitsubishi D30V d30v-*-*
5424 Fujitsu FR30 fr30-*-elf*
5425 OS/9000 i[34]86-*-os9k
5426 I960 with MON960 i960-*-coff
5428 * MIPS $fp behavior changed
5430 The convenience variable $fp, for the MIPS, now consistently returns
5431 the address of the current frame's base. Previously, depending on the
5432 context, $fp could refer to either $sp or the current frame's base
5433 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5434 The GNU Source-Level Debugger''.
5436 *** Changes in GDB 5.3:
5438 * GNU/Linux shared library multi-threaded performance improved.
5440 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5441 `/proc', in preference to `ptrace' for memory reads. This may result
5442 in an improvement in the start-up time of multi-threaded, shared
5443 library applications when run under GDB. One GDB user writes: ``loads
5444 shared libs like mad''.
5446 * ``gdbserver'' now supports multi-threaded applications on some targets
5448 Support for debugging multi-threaded applications which use
5449 the GNU/Linux LinuxThreads package has been added for
5450 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5451 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5453 * GDB now supports C/C++ preprocessor macros.
5455 GDB now expands preprocessor macro invocations in C/C++ expressions,
5456 and provides various commands for showing macro definitions and how
5459 The new command `macro expand EXPRESSION' expands any macro
5460 invocations in expression, and shows the result.
5462 The new command `show macro MACRO-NAME' shows the definition of the
5463 macro named MACRO-NAME, and where it was defined.
5465 Most compilers don't include information about macros in the debugging
5466 information by default. In GCC 3.1, for example, you need to compile
5467 your program with the options `-gdwarf-2 -g3'. If the macro
5468 information is present in the executable, GDB will read it.
5470 * Multi-arched targets.
5472 DEC Alpha (partial) alpha*-*-*
5473 DEC VAX (partial) vax-*-*
5475 National Semiconductor NS32000 (partial) ns32k-*-*
5476 Motorola 68000 (partial) m68k-*-*
5477 Motorola MCORE mcore-*-*
5481 Fujitsu FRV architecture added by Red Hat frv*-*-*
5484 * New native configurations
5486 Alpha NetBSD alpha*-*-netbsd*
5487 SH NetBSD sh*-*-netbsdelf*
5488 MIPS NetBSD mips*-*-netbsd*
5489 UltraSPARC NetBSD sparc64-*-netbsd*
5491 * OBSOLETE configurations and files
5493 Configurations that have been declared obsolete in this release have
5494 been commented out. Unless there is activity to revive these
5495 configurations, the next release of GDB will have their sources
5496 permanently REMOVED.
5498 Mitsubishi D30V d30v-*-*
5499 OS/9000 i[34]86-*-os9k
5500 IBM AIX PS/2 i[3456]86-*-aix
5501 Fujitsu FR30 fr30-*-elf*
5502 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5503 Argonaut Risc Chip (ARC) arc-*-*
5504 i386 running Mach 3.0 i[3456]86-*-mach3*
5505 i386 running Mach i[3456]86-*-mach*
5506 i386 running OSF/1 i[3456]86-*osf1mk*
5507 HP/Apollo 68k Family m68*-apollo*-sysv*,
5509 m68*-hp-bsd*, m68*-hp-hpux*
5510 I960 with MON960 i960-*-coff
5512 * OBSOLETE languages
5514 CHILL, a Pascal like language used by telecommunications companies.
5516 * REMOVED configurations and files
5518 AMD 29k family via UDI a29k-amd-udi, udi29k
5519 A29K VxWorks a29k-*-vxworks
5520 AMD 29000 embedded, using EBMON a29k-none-none
5521 AMD 29000 embedded with COFF a29k-none-coff
5522 AMD 29000 embedded with a.out a29k-none-aout
5524 testsuite/gdb.hp/gdb.threads-hp/ directory
5526 * New command "set max-user-call-depth <nnn>"
5528 This command allows the user to limit the call depth of user-defined
5529 commands. The default is 1024.
5531 * Changes in FreeBSD/i386 native debugging.
5533 Support for the "generate-core-file" has been added.
5535 * New commands "dump", "append", and "restore".
5537 These commands allow data to be copied from target memory
5538 to a bfd-format or binary file (dump and append), and back
5539 from a file into memory (restore).
5541 * Improved "next/step" support on multi-processor Alpha Tru64.
5543 The previous single-step mechanism could cause unpredictable problems,
5544 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5545 of a software single-step mechanism prevents this.
5547 *** Changes in GDB 5.2.1:
5555 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5556 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5557 Fix, by Joel Brobecker imported from mainline.
5559 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5560 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5561 Fix, by Fred Fish, imported from mainline.
5563 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5564 Surprisingly enough, it works now.
5565 By Michal Ludvig, imported from mainline.
5567 i386 hardware watchpoint support:
5568 avoid misses on second run for some targets.
5569 By Pierre Muller, imported from mainline.
5571 *** Changes in GDB 5.2:
5573 * New command "set trust-readonly-sections on[off]".
5575 This command is a hint that tells gdb that read-only sections
5576 really are read-only (ie. that their contents will not change).
5577 In this mode, gdb will go to the object file rather than the
5578 target to read memory from read-only sections (such as ".text").
5579 This can be a significant performance improvement on some
5580 (notably embedded) targets.
5582 * New command "generate-core-file" (or "gcore").
5584 This new gdb command allows the user to drop a core file of the child
5585 process state at any time. So far it's been implemented only for
5586 GNU/Linux and Solaris, but should be relatively easily ported to other
5587 hosts. Argument is core file name (defaults to core.<pid>).
5589 * New command line option
5591 GDB now accepts --pid or -p followed by a process id.
5593 * Change in command line behavior -- corefiles vs. process ids.
5595 There is a subtle behavior in the way in which GDB handles
5596 command line arguments. The first non-flag argument is always
5597 a program to debug, but the second non-flag argument may either
5598 be a corefile or a process id. Previously, GDB would attempt to
5599 open the second argument as a corefile, and if that failed, would
5600 issue a superfluous error message and then attempt to attach it as
5601 a process. Now, if the second argument begins with a non-digit,
5602 it will be treated as a corefile. If it begins with a digit,
5603 GDB will attempt to attach it as a process, and if no such process
5604 is found, will then attempt to open it as a corefile.
5606 * Changes in ARM configurations.
5608 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5609 configuration is fully multi-arch.
5611 * New native configurations
5613 ARM NetBSD arm*-*-netbsd*
5614 x86 OpenBSD i[3456]86-*-openbsd*
5615 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5616 Sparc64 running FreeBSD sparc64-*-freebsd*
5620 Sanyo XStormy16 xstormy16-elf
5622 * OBSOLETE configurations and files
5624 Configurations that have been declared obsolete in this release have
5625 been commented out. Unless there is activity to revive these
5626 configurations, the next release of GDB will have their sources
5627 permanently REMOVED.
5629 AMD 29k family via UDI a29k-amd-udi, udi29k
5630 A29K VxWorks a29k-*-vxworks
5631 AMD 29000 embedded, using EBMON a29k-none-none
5632 AMD 29000 embedded with COFF a29k-none-coff
5633 AMD 29000 embedded with a.out a29k-none-aout
5635 testsuite/gdb.hp/gdb.threads-hp/ directory
5637 * REMOVED configurations and files
5639 TI TMS320C80 tic80-*-*
5641 PowerPC Solaris powerpcle-*-solaris*
5642 PowerPC Windows NT powerpcle-*-cygwin32
5643 PowerPC Netware powerpc-*-netware*
5644 Harris/CXUX m88k m88*-harris-cxux*
5645 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5646 ns32k-utek-sysv* ns32k-utek-*
5647 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5648 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5649 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5650 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5651 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5653 * Changes to command line processing
5655 The new `--args' feature can be used to specify command-line arguments
5656 for the inferior from gdb's command line.
5658 * Changes to key bindings
5660 There is a new `operate-and-get-next' function bound to `C-o'.
5662 *** Changes in GDB 5.1.1
5664 Fix compile problem on DJGPP.
5666 Fix a problem with floating-point registers on the i386 being
5669 Fix to stop GDB crashing on .debug_str debug info.
5671 Numerous documentation fixes.
5673 Numerous testsuite fixes.
5675 *** Changes in GDB 5.1:
5677 * New native configurations
5679 Alpha FreeBSD alpha*-*-freebsd*
5680 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5681 MIPS GNU/Linux mips*-*-linux*
5682 MIPS SGI Irix 6.x mips*-sgi-irix6*
5683 ia64 AIX ia64-*-aix*
5684 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5688 Motorola 68HC11 and 68HC12 m68hc11-elf
5690 UltraSparc running GNU/Linux sparc64-*-linux*
5692 * OBSOLETE configurations and files
5694 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5695 Harris/CXUX m88k m88*-harris-cxux*
5696 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5697 ns32k-utek-sysv* ns32k-utek-*
5698 TI TMS320C80 tic80-*-*
5700 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5701 PowerPC Solaris powerpcle-*-solaris*
5702 PowerPC Windows NT powerpcle-*-cygwin32
5703 PowerPC Netware powerpc-*-netware*
5704 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5705 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5706 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5707 Apple Macintosh (MPW) host N/A
5709 stuff.c (Program to stuff files into a specially prepared space in kdb)
5710 kdb-start.c (Main loop for the standalone kernel debugger)
5712 Configurations that have been declared obsolete in this release have
5713 been commented out. Unless there is activity to revive these
5714 configurations, the next release of GDB will have their sources
5715 permanently REMOVED.
5717 * REMOVED configurations and files
5719 Altos 3068 m68*-altos-*
5720 Convex c1-*-*, c2-*-*
5722 ARM RISCix arm-*-* (as host)
5726 * GDB has been converted to ISO C.
5728 GDB's source code has been converted to ISO C. In particular, the
5729 sources are fully protoized, and rely on standard headers being
5734 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5736 * The MI enabled by default.
5738 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5739 revised and enabled by default. Packages which use GDB as a debugging
5740 engine behind a UI or another front end are encouraged to switch to
5741 using the GDB/MI interface, instead of the old annotations interface
5742 which is now deprecated.
5744 * Support for debugging Pascal programs.
5746 GDB now includes support for debugging Pascal programs. The following
5747 main features are supported:
5749 - Pascal-specific data types such as sets;
5751 - automatic recognition of Pascal sources based on file-name
5754 - Pascal-style display of data types, variables, and functions;
5756 - a Pascal expression parser.
5758 However, some important features are not yet supported.
5760 - Pascal string operations are not supported at all;
5762 - there are some problems with boolean types;
5764 - Pascal type hexadecimal constants are not supported
5765 because they conflict with the internal variables format;
5767 - support for Pascal objects and classes is not full yet;
5769 - unlike Pascal, GDB is case-sensitive for symbol names.
5771 * Changes in completion.
5773 Commands such as `shell', `run' and `set args', which pass arguments
5774 to inferior programs, now complete on file names, similar to what
5775 users expect at the shell prompt.
5777 Commands which accept locations, such as `disassemble', `print',
5778 `breakpoint', `until', etc. now complete on filenames as well as
5779 program symbols. Thus, if you type "break foob TAB", and the source
5780 files linked into the programs include `foobar.c', that file name will
5781 be one of the candidates for completion. However, file names are not
5782 considered for completion after you typed a colon that delimits a file
5783 name from a name of a function in that file, as in "break foo.c:bar".
5785 `set demangle-style' completes on available demangling styles.
5787 * New platform-independent commands:
5789 It is now possible to define a post-hook for a command as well as a
5790 hook that runs before the command. For more details, see the
5791 documentation of `hookpost' in the GDB manual.
5793 * Changes in GNU/Linux native debugging.
5795 Support for debugging multi-threaded programs has been completely
5796 revised for all platforms except m68k and sparc. You can now debug as
5797 many threads as your system allows you to have.
5799 Attach/detach is supported for multi-threaded programs.
5801 Support for SSE registers was added for x86. This doesn't work for
5802 multi-threaded programs though.
5804 * Changes in MIPS configurations.
5806 Multi-arch support is enabled for all MIPS configurations.
5808 GDB can now be built as native debugger on SGI Irix 6.x systems for
5809 debugging n32 executables. (Debugging 64-bit executables is not yet
5812 * Unified support for hardware watchpoints in all x86 configurations.
5814 Most (if not all) native x86 configurations support hardware-assisted
5815 breakpoints and watchpoints in a unified manner. This support
5816 implements debug register sharing between watchpoints, which allows to
5817 put a virtually infinite number of watchpoints on the same address,
5818 and also supports watching regions up to 16 bytes with several debug
5821 The new maintenance command `maintenance show-debug-regs' toggles
5822 debugging print-outs in functions that insert, remove, and test
5823 watchpoints and hardware breakpoints.
5825 * Changes in the DJGPP native configuration.
5827 New command ``info dos sysinfo'' displays assorted information about
5828 the CPU, OS, memory, and DPMI server.
5830 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5831 display information about segment descriptors stored in GDT, LDT, and
5834 New commands ``info dos pde'' and ``info dos pte'' display entries
5835 from Page Directory and Page Tables (for now works with CWSDPMI only).
5836 New command ``info dos address-pte'' displays the Page Table entry for
5837 a given linear address.
5839 GDB can now pass command lines longer than 126 characters to the
5840 program being debugged (requires an update to the libdbg.a library
5841 which is part of the DJGPP development kit).
5843 DWARF2 debug info is now supported.
5845 It is now possible to `step' and `next' through calls to `longjmp'.
5847 * Changes in documentation.
5849 All GDB documentation was converted to GFDL, the GNU Free
5850 Documentation License.
5852 Tracepoints-related commands are now fully documented in the GDB
5855 TUI, the Text-mode User Interface, is now documented in the manual.
5857 Tracepoints-related commands are now fully documented in the GDB
5860 The "GDB Internals" manual now has an index. It also includes
5861 documentation of `ui_out' functions, GDB coding standards, x86
5862 hardware watchpoints, and memory region attributes.
5864 * GDB's version number moved to ``version.in''
5866 The Makefile variable VERSION has been replaced by the file
5867 ``version.in''. People creating GDB distributions should update the
5868 contents of this file.
5872 GUD support is now a standard part of the EMACS distribution.
5874 *** Changes in GDB 5.0:
5876 * Improved support for debugging FP programs on x86 targets
5878 Unified and much-improved support for debugging floating-point
5879 programs on all x86 targets. In particular, ``info float'' now
5880 displays the FP registers in the same format on all x86 targets, with
5881 greater level of detail.
5883 * Improvements and bugfixes in hardware-assisted watchpoints
5885 It is now possible to watch array elements, struct members, and
5886 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5887 on x86 targets no longer erroneously trigger when the address is
5890 * Improvements in the native DJGPP version of GDB
5892 The distribution now includes all the scripts and auxiliary files
5893 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5894 machines ``out of the box''.
5896 The DJGPP version can now debug programs that use signals. It is
5897 possible to catch signals that happened in the debuggee, deliver
5898 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5899 would kill the program being debugged.) Programs that hook hardware
5900 interrupts (keyboard, timer, etc.) can also be debugged.
5902 It is now possible to debug DJGPP programs that redirect their
5903 standard handles or switch them to raw (as opposed to cooked) mode, or
5904 even close them. The command ``run < foo > bar'' works as expected,
5905 and ``info terminal'' reports useful information about the debuggee's
5906 terminal, including raw/cooked mode, redirection, etc.
5908 The DJGPP version now uses termios functions for console I/O, which
5909 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5912 DOS-style file names with drive letters are now fully supported by
5915 It is now possible to debug DJGPP programs that switch their working
5916 directory. It is also possible to rerun the debuggee any number of
5917 times without restarting GDB; thus, you can use the same setup,
5918 breakpoints, etc. for many debugging sessions.
5920 * New native configurations
5922 ARM GNU/Linux arm*-*-linux*
5923 PowerPC GNU/Linux powerpc-*-linux*
5927 Motorola MCore mcore-*-*
5928 x86 VxWorks i[3456]86-*-vxworks*
5929 PowerPC VxWorks powerpc-*-vxworks*
5930 TI TMS320C80 tic80-*-*
5932 * OBSOLETE configurations
5934 Altos 3068 m68*-altos-*
5935 Convex c1-*-*, c2-*-*
5937 ARM RISCix arm-*-* (as host)
5940 Configurations that have been declared obsolete will be commented out,
5941 but the code will be left in place. If there is no activity to revive
5942 these configurations before the next release of GDB, the sources will
5943 be permanently REMOVED.
5945 * Gould support removed
5947 Support for the Gould PowerNode and NP1 has been removed.
5949 * New features for SVR4
5951 On SVR4 native platforms (such as Solaris), if you attach to a process
5952 without first loading a symbol file, GDB will now attempt to locate and
5953 load symbols from the running process's executable file.
5955 * Many C++ enhancements
5957 C++ support has been greatly improved. Overload resolution now works properly
5958 in almost all cases. RTTI support is on the way.
5960 * Remote targets can connect to a sub-program
5962 A popen(3) style serial-device has been added. This device starts a
5963 sub-process (such as a stand-alone simulator) and then communicates
5964 with that. The sub-program to run is specified using the syntax
5965 ``|<program> <args>'' vis:
5967 (gdb) set remotedebug 1
5968 (gdb) target extended-remote |mn10300-elf-sim program-args
5970 * MIPS 64 remote protocol
5972 A long standing bug in the mips64 remote protocol where by GDB
5973 expected certain 32 bit registers (ex SR) to be transfered as 32
5974 instead of 64 bits has been fixed.
5976 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5977 added to provide backward compatibility with older versions of GDB.
5979 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5981 The command ``set remotebinarydownload'' command has been replaced by
5982 ``set remote X-packet''. Other commands in ``set remote'' family
5983 include ``set remote P-packet''.
5985 * Breakpoint commands accept ranges.
5987 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5988 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5989 ``tracepoint passcount'' also accepts a range of tracepoints.
5991 * ``apropos'' command added.
5993 The ``apropos'' command searches through command names and
5994 documentation strings, printing out matches, making it much easier to
5995 try to find a command that does what you are looking for.
5999 A new machine oriented interface (MI) has been added to GDB. This
6000 interface is designed for debug environments running GDB as a separate
6001 process. This is part of the long term libGDB project. See the
6002 "GDB/MI" chapter of the GDB manual for further information. It can be
6003 enabled by configuring with:
6005 .../configure --enable-gdbmi
6007 *** Changes in GDB-4.18:
6009 * New native configurations
6011 HP-UX 10.20 hppa*-*-hpux10.20
6012 HP-UX 11.x hppa*-*-hpux11.0*
6013 M68K GNU/Linux m68*-*-linux*
6017 Fujitsu FR30 fr30-*-elf*
6018 Intel StrongARM strongarm-*-*
6019 Mitsubishi D30V d30v-*-*
6021 * OBSOLETE configurations
6023 Gould PowerNode, NP1 np1-*-*, pn-*-*
6025 Configurations that have been declared obsolete will be commented out,
6026 but the code will be left in place. If there is no activity to revive
6027 these configurations before the next release of GDB, the sources will
6028 be permanently REMOVED.
6032 As a compatibility experiment, GDB's source files buildsym.h and
6033 buildsym.c have been converted to pure standard C, no longer
6034 containing any K&R compatibility code. We believe that all systems in
6035 use today either come with a standard C compiler, or have a GCC port
6036 available. If this is not true, please report the affected
6037 configuration to bug-gdb@gnu.org immediately. See the README file for
6038 information about getting a standard C compiler if you don't have one
6043 GDB now uses readline 2.2.
6045 * set extension-language
6047 You can now control the mapping between filename extensions and source
6048 languages by using the `set extension-language' command. For instance,
6049 you can ask GDB to treat .c files as C++ by saying
6050 set extension-language .c c++
6051 The command `info extensions' lists all of the recognized extensions
6052 and their associated languages.
6054 * Setting processor type for PowerPC and RS/6000
6056 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6057 you can use the `set processor' command to specify what variant of the
6058 PowerPC family you are debugging. The command
6062 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6063 following PowerPC and RS6000 variants:
6065 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6066 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6068 403GC IBM PowerPC 403GC
6069 505 Motorola PowerPC 505
6070 860 Motorola PowerPC 860 or 850
6071 601 Motorola PowerPC 601
6072 602 Motorola PowerPC 602
6073 603 Motorola/IBM PowerPC 603 or 603e
6074 604 Motorola PowerPC 604 or 604e
6075 750 Motorola/IBM PowerPC 750 or 750
6077 At the moment, this command just tells GDB what to name the
6078 special-purpose processor registers. Since almost all the affected
6079 registers are inaccessible to user-level programs, this command is
6080 only useful for remote debugging in its present form.
6084 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6085 more extensive support for HP-UX. Added features include shared
6086 library support, kernel threads and hardware watchpoints for 11.00,
6087 support for HP's ANSI C and C++ compilers, and a compatibility mode
6088 for xdb and dbx commands.
6092 HP's donation includes the new concept of catchpoints, which is a
6093 generalization of the old catch command. On HP-UX, it is now possible
6094 to catch exec, fork, and vfork, as well as library loading.
6096 This means that the existing catch command has changed; its first
6097 argument now specifies the type of catch to be set up. See the
6098 output of "help catch" for a list of catchpoint types.
6100 * Debugging across forks
6102 On HP-UX, you can choose which process to debug when a fork() happens
6107 HP has donated a curses-based terminal user interface (TUI). To get
6108 it, build with --enable-tui. Although this can be enabled for any
6109 configuration, at present it only works for native HP debugging.
6111 * GDB remote protocol additions
6113 A new protocol packet 'X' that writes binary data is now available.
6114 Default behavior is to try 'X', then drop back to 'M' if the stub
6115 fails to respond. The settable variable `remotebinarydownload'
6116 allows explicit control over the use of 'X'.
6118 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6119 full 64-bit address. The command
6121 set remoteaddresssize 32
6123 can be used to revert to the old behaviour. For existing remote stubs
6124 the change should not be noticed, as the additional address information
6127 In order to assist in debugging stubs, you may use the maintenance
6128 command `packet' to send any text string to the stub. For instance,
6130 maint packet heythere
6132 sends the packet "$heythere#<checksum>". Note that it is very easy to
6133 disrupt a debugging session by sending the wrong packet at the wrong
6136 The compare-sections command allows you to compare section data on the
6137 target to what is in the executable file without uploading or
6138 downloading, by comparing CRC checksums.
6140 * Tracing can collect general expressions
6142 You may now collect general expressions at tracepoints. This requires
6143 further additions to the target-side stub; see tracepoint.c and
6144 doc/agentexpr.texi for further details.
6146 * mask-address variable for Mips
6148 For Mips targets, you may control the zeroing of the upper 32 bits of
6149 a 64-bit address by entering `set mask-address on'. This is mainly
6150 of interest to users of embedded R4xxx and R5xxx processors.
6152 * Higher serial baud rates
6154 GDB's serial code now allows you to specify baud rates 57600, 115200,
6155 230400, and 460800 baud. (Note that your host system may not be able
6156 to achieve all of these rates.)
6160 The i960 configuration now includes an initial implementation of a
6161 builtin simulator, contributed by Jim Wilson.
6164 *** Changes in GDB-4.17:
6166 * New native configurations
6168 Alpha GNU/Linux alpha*-*-linux*
6169 Unixware 2.x i[3456]86-unixware2*
6170 Irix 6.x mips*-sgi-irix6*
6171 PowerPC GNU/Linux powerpc-*-linux*
6172 PowerPC Solaris powerpcle-*-solaris*
6173 Sparc GNU/Linux sparc-*-linux*
6174 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6178 Argonaut Risc Chip (ARC) arc-*-*
6179 Hitachi H8/300S h8300*-*-*
6180 Matsushita MN10200 w/simulator mn10200-*-*
6181 Matsushita MN10300 w/simulator mn10300-*-*
6182 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6183 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6184 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6185 Mitsubishi D10V w/simulator d10v-*-*
6186 Mitsubishi M32R/D w/simulator m32r-*-elf*
6187 Tsqware Sparclet sparclet-*-*
6188 NEC V850 w/simulator v850-*-*
6190 * New debugging protocols
6192 ARM with RDI protocol arm*-*-*
6193 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6194 DDB and LSI variants of PMON protocol mips*-*-*
6195 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6196 PowerPC with SDS protocol powerpc{,le}-*-eabi
6197 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6201 All configurations can now understand and use the DWARF 2 debugging
6202 format. The choice is automatic, if the symbol file contains DWARF 2
6207 GDB now includes basic Java language support. This support is
6208 only useful with Java compilers that produce native machine code.
6210 * solib-absolute-prefix and solib-search-path
6212 For SunOS and SVR4 shared libraries, you may now set the prefix for
6213 loading absolute shared library symbol files, and the search path for
6214 locating non-absolute shared library symbol files.
6216 * Live range splitting
6218 GDB can now effectively debug code for which GCC has performed live
6219 range splitting as part of its optimization. See gdb/doc/LRS for
6220 more details on the expected format of the stabs information.
6224 GDB's support for the GNU Hurd, including thread debugging, has been
6225 updated to work with current versions of the Hurd.
6229 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6230 instruction set. ARM GDB automatically detects when Thumb
6231 instructions are in use, and adjusts disassembly and backtracing
6236 GDB's MIPS target configurations now handle the MIP16 16-bit
6241 GDB now includes support for overlays; if an executable has been
6242 linked such that multiple sections are based at the same address, GDB
6243 will decide which section to use for symbolic info. You can choose to
6244 control the decision manually, using overlay commands, or implement
6245 additional target-side support and use "overlay load-target" to bring
6246 in the overlay mapping. Do "help overlay" for more detail.
6250 The command "info symbol <address>" displays information about
6251 the symbol at the specified address.
6255 The standard remote protocol now includes an extension that allows
6256 asynchronous collection and display of trace data. This requires
6257 extensive support in the target-side debugging stub. Tracing mode
6258 includes a new interaction mode in GDB and new commands: see the
6259 file tracepoint.c for more details.
6263 Configurations for embedded MIPS now include a simulator contributed
6264 by Cygnus Solutions. The simulator supports the instruction sets
6265 of most MIPS variants.
6269 Sparc configurations may now include the ERC32 simulator contributed
6270 by the European Space Agency. The simulator is not built into
6271 Sparc targets by default; configure with --enable-sim to include it.
6275 For target configurations that may include multiple variants of a
6276 basic architecture (such as MIPS and SH), you may now set the
6277 architecture explicitly. "set arch" sets, "info arch" lists
6278 the possible architectures.
6280 *** Changes in GDB-4.16:
6282 * New native configurations
6284 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6285 M68K NetBSD m68k-*-netbsd*
6286 PowerPC AIX 4.x powerpc-*-aix*
6287 PowerPC MacOS powerpc-*-macos*
6288 PowerPC Windows NT powerpcle-*-cygwin32
6289 RS/6000 AIX 4.x rs6000-*-aix4*
6293 ARM with RDP protocol arm-*-*
6294 I960 with MON960 i960-*-coff
6295 MIPS VxWorks mips*-*-vxworks*
6296 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6297 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6299 Matra Sparclet sparclet-*-*
6303 The powerpc-eabi configuration now includes the PSIM simulator,
6304 contributed by Andrew Cagney, with assistance from Mike Meissner.
6305 PSIM is a very elaborate model of the PowerPC, including not only
6306 basic instruction set execution, but also details of execution unit
6307 performance and I/O hardware. See sim/ppc/README for more details.
6311 GDB now works with Solaris 2.5.
6313 * Windows 95/NT native
6315 GDB will now work as a native debugger on Windows 95 and Windows NT.
6316 To build it from source, you must use the "gnu-win32" environment,
6317 which uses a DLL to emulate enough of Unix to run the GNU tools.
6318 Further information, binaries, and sources are available at
6319 ftp.cygnus.com, under pub/gnu-win32.
6321 * dont-repeat command
6323 If a user-defined command includes the command `dont-repeat', then the
6324 command will not be repeated if the user just types return. This is
6325 useful if the command is time-consuming to run, so that accidental
6326 extra keystrokes don't run the same command many times.
6328 * Send break instead of ^C
6330 The standard remote protocol now includes an option to send a break
6331 rather than a ^C to the target in order to interrupt it. By default,
6332 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6334 * Remote protocol timeout
6336 The standard remote protocol includes a new variable `remotetimeout'
6337 that allows you to set the number of seconds before GDB gives up trying
6338 to read from the target. The default value is 2.
6340 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6342 By default GDB will automatically keep track of objects as they are
6343 loaded and unloaded by the dynamic linker. By using the command `set
6344 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6345 when shared library events occur, thus allowing you to set breakpoints
6346 in shared libraries which are explicitly loaded by the inferior.
6348 Note this feature does not work on hpux8. On hpux9 you must link
6349 /usr/lib/end.o into your program. This feature should work
6350 automatically on hpux10.
6352 * Irix 5.x hardware watchpoint support
6354 Irix 5 configurations now support the use of hardware watchpoints.
6356 * Mips protocol "SYN garbage limit"
6358 When debugging a Mips target using the `target mips' protocol, you
6359 may set the number of characters that GDB will ignore by setting
6360 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6361 every character. The default value is 1050.
6363 * Recording and replaying remote debug sessions
6365 If you set `remotelogfile' to the name of a file, gdb will write to it
6366 a recording of a remote debug session. This recording may then be
6367 replayed back to gdb using "gdbreplay". See gdbserver/README for
6368 details. This is useful when you have a problem with GDB while doing
6369 remote debugging; you can make a recording of the session and send it
6370 to someone else, who can then recreate the problem.
6372 * Speedups for remote debugging
6374 GDB includes speedups for downloading and stepping MIPS systems using
6375 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6376 and more efficient S-record downloading.
6378 * Memory use reductions and statistics collection
6380 GDB now uses less memory and reports statistics about memory usage.
6381 Try the `maint print statistics' command, for example.
6383 *** Changes in GDB-4.15:
6385 * Psymtabs for XCOFF
6387 The symbol reader for AIX GDB now uses partial symbol tables. This
6388 can greatly improve startup time, especially for large executables.
6390 * Remote targets use caching
6392 Remote targets now use a data cache to speed up communication with the
6393 remote side. The data cache could lead to incorrect results because
6394 it doesn't know about volatile variables, thus making it impossible to
6395 debug targets which use memory mapped I/O devices. `set remotecache
6396 off' turns the the data cache off.
6398 * Remote targets may have threads
6400 The standard remote protocol now includes support for multiple threads
6401 in the target system, using new protocol commands 'H' and 'T'. See
6402 gdb/remote.c for details.
6406 If GDB is configured with `--enable-netrom', then it will include
6407 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6408 acts as though it is a bank of ROM on the target board, but you can
6409 write into it over the network. GDB's support consists only of
6410 support for fast loading into the emulated ROM; to debug, you must use
6411 another protocol, such as standard remote protocol. The usual
6412 sequence is something like
6414 target nrom <netrom-hostname>
6416 target remote <netrom-hostname>:1235
6420 GDB now includes support for the Apple Macintosh, as a host only. It
6421 may be run as either an MPW tool or as a standalone application, and
6422 it can debug through the serial port. All the usual GDB commands are
6423 available, but to the target command, you must supply "serial" as the
6424 device type instead of "/dev/ttyXX". See mpw-README in the main
6425 directory for more information on how to build. The MPW configuration
6426 scripts */mpw-config.in support only a few targets, and only the
6427 mips-idt-ecoff target has been tested.
6431 GDB configuration now uses autoconf. This is not user-visible,
6432 but does simplify configuration and building.
6436 GDB now supports hpux10.
6438 *** Changes in GDB-4.14:
6440 * New native configurations
6442 x86 FreeBSD i[345]86-*-freebsd
6443 x86 NetBSD i[345]86-*-netbsd
6444 NS32k NetBSD ns32k-*-netbsd
6445 Sparc NetBSD sparc-*-netbsd
6449 A29K VxWorks a29k-*-vxworks
6450 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6451 CPU32 EST-300 emulator m68*-*-est*
6452 PowerPC ELF powerpc-*-elf
6455 * Alpha OSF/1 support for procfs
6457 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6458 possible to attach to running processes. As the mounting of the /proc
6459 filesystem is optional on the Alpha, GDB automatically determines
6460 the availability of /proc during startup. This can lead to problems
6461 if /proc is unmounted after GDB has been started.
6463 * Arguments to user-defined commands
6465 User commands may accept up to 10 arguments separated by whitespace.
6466 Arguments are accessed within the user command via $arg0..$arg9. A
6469 print $arg0 + $arg1 + $arg2
6471 To execute the command use:
6474 Defines the command "adder" which prints the sum of its three arguments.
6475 Note the arguments are text substitutions, so they may reference variables,
6476 use complex expressions, or even perform inferior function calls.
6478 * New `if' and `while' commands
6480 This makes it possible to write more sophisticated user-defined
6481 commands. Both commands take a single argument, which is the
6482 expression to evaluate, and must be followed by the commands to
6483 execute, one per line, if the expression is nonzero, the list being
6484 terminated by the word `end'. The `if' command list may include an
6485 `else' word, which causes the following commands to be executed only
6486 if the expression is zero.
6488 * Fortran source language mode
6490 GDB now includes partial support for Fortran 77. It will recognize
6491 Fortran programs and can evaluate a subset of Fortran expressions, but
6492 variables and functions may not be handled correctly. GDB will work
6493 with G77, but does not yet know much about symbols emitted by other
6496 * Better HPUX support
6498 Most debugging facilities now work on dynamic executables for HPPAs
6499 running hpux9 or later. You can attach to running dynamically linked
6500 processes, but by default the dynamic libraries will be read-only, so
6501 for instance you won't be able to put breakpoints in them. To change
6502 that behavior do the following before running the program:
6508 This will cause the libraries to be mapped private and read-write.
6509 To revert to the normal behavior, do this:
6515 You cannot set breakpoints or examine data in the library until after
6516 the library is loaded if the function/data symbols do not have
6519 GDB can now also read debug symbols produced by the HP C compiler on
6520 HPPAs (sorry, no C++, Fortran or 68k support).
6522 * Target byte order now dynamically selectable
6524 You can choose which byte order to use with a target system, via the
6525 commands "set endian big" and "set endian little", and you can see the
6526 current setting by using "show endian". You can also give the command
6527 "set endian auto", in which case GDB will use the byte order
6528 associated with the executable. Currently, only embedded MIPS
6529 configurations support dynamic selection of target byte order.
6531 * New DOS host serial code
6533 This version uses DPMI interrupts to handle buffered I/O, so you
6534 no longer need to run asynctsr when debugging boards connected to
6537 *** Changes in GDB-4.13:
6539 * New "complete" command
6541 This lists all the possible completions for the rest of the line, if it
6542 were to be given as a command itself. This is intended for use by emacs.
6544 * Trailing space optional in prompt
6546 "set prompt" no longer adds a space for you after the prompt you set. This
6547 allows you to set a prompt which ends in a space or one that does not.
6549 * Breakpoint hit counts
6551 "info break" now displays a count of the number of times the breakpoint
6552 has been hit. This is especially useful in conjunction with "ignore"; you
6553 can ignore a large number of breakpoint hits, look at the breakpoint info
6554 to see how many times the breakpoint was hit, then run again, ignoring one
6555 less than that number, and this will get you quickly to the last hit of
6558 * Ability to stop printing at NULL character
6560 "set print null-stop" will cause GDB to stop printing the characters of
6561 an array when the first NULL is encountered. This is useful when large
6562 arrays actually contain only short strings.
6564 * Shared library breakpoints
6566 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6567 breakpoints in shared libraries before the executable is run.
6569 * Hardware watchpoints
6571 There is a new hardware breakpoint for the watch command for sparclite
6572 targets. See gdb/sparclite/hw_breakpoint.note.
6574 Hardware watchpoints are also now supported under GNU/Linux.
6578 Annotations have been added. These are for use with graphical interfaces,
6579 and are still experimental. Currently only gdba.el uses these.
6581 * Improved Irix 5 support
6583 GDB now works properly with Irix 5.2.
6585 * Improved HPPA support
6587 GDB now works properly with the latest GCC and GAS.
6589 * New native configurations
6591 Sequent PTX4 i[34]86-sequent-ptx4
6592 HPPA running OSF/1 hppa*-*-osf*
6593 Atari TT running SVR4 m68*-*-sysv4*
6594 RS/6000 LynxOS rs6000-*-lynxos*
6598 OS/9000 i[34]86-*-os9k
6599 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6602 * Hitachi SH7000 and E7000-PC ICE support
6604 There is now support for communicating with the Hitachi E7000-PC ICE.
6605 This is available automatically when GDB is configured for the SH.
6609 As usual, a variety of small fixes and improvements, both generic
6610 and configuration-specific. See the ChangeLog for more detail.
6612 *** Changes in GDB-4.12:
6614 * Irix 5 is now supported
6618 GDB-4.12 on the HPPA has a number of changes which make it unable
6619 to debug the output from the currently released versions of GCC and
6620 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6621 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6622 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6625 *** Changes in GDB-4.11:
6627 * User visible changes:
6631 The "set remotedebug" option is now consistent between the mips remote
6632 target, remote targets using the gdb-specific protocol, UDI (AMD's
6633 debug protocol for the 29k) and the 88k bug monitor. It is now an
6634 integer specifying a debug level (normally 0 or 1, but 2 means more
6635 debugging info for the mips target).
6637 * DEC Alpha native support
6639 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6640 debug info, but GDB works fairly well with the DEC compiler and should
6641 work with a future GCC release. See the README file for a few
6642 Alpha-specific notes.
6644 * Preliminary thread implementation
6646 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6648 * LynxOS native and target support for 386
6650 This release has been hosted on LynxOS 2.2, and also can be configured
6651 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6654 * Improvements in C++ mangling/demangling.
6656 This release has much better g++ debugging, specifically in name
6657 mangling/demangling, virtual function calls, print virtual table,
6658 call methods, ...etc.
6660 *** Changes in GDB-4.10:
6662 * User visible changes:
6664 Remote debugging using the GDB-specific (`target remote') protocol now
6665 supports the `load' command. This is only useful if you have some
6666 other way of getting the stub to the target system, and you can put it
6667 somewhere in memory where it won't get clobbered by the download.
6669 Filename completion now works.
6671 When run under emacs mode, the "info line" command now causes the
6672 arrow to point to the line specified. Also, "info line" prints
6673 addresses in symbolic form (as well as hex).
6675 All vxworks based targets now support a user settable option, called
6676 vxworks-timeout. This option represents the number of seconds gdb
6677 should wait for responses to rpc's. You might want to use this if
6678 your vxworks target is, perhaps, a slow software simulator or happens
6679 to be on the far side of a thin network line.
6683 This release contains support for using a DEC alpha as a GDB host for
6684 cross debugging. Native alpha debugging is not supported yet.
6687 *** Changes in GDB-4.9:
6691 This is the first GDB release which is accompanied by a matching testsuite.
6692 The testsuite requires installation of dejagnu, which should be available
6693 via ftp from most sites that carry GNU software.
6697 'Cfront' style demangling has had its name changed to 'ARM' style, to
6698 emphasize that it was written from the specifications in the C++ Annotated
6699 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6700 disclaimers, it still generated too much confusion with users attempting to
6701 use gdb with AT&T cfront.
6705 GDB now uses a standard remote interface to a simulator library.
6706 So far, the library contains simulators for the Zilog Z8001/2, the
6707 Hitachi H8/300, H8/500 and Super-H.
6709 * New targets supported
6711 H8/300 simulator h8300-hitachi-hms or h8300hms
6712 H8/500 simulator h8500-hitachi-hms or h8500hms
6713 SH simulator sh-hitachi-hms or sh
6714 Z8000 simulator z8k-zilog-none or z8ksim
6715 IDT MIPS board over serial line mips-idt-ecoff
6717 Cross-debugging to GO32 targets is supported. It requires a custom
6718 version of the i386-stub.c module which is integrated with the
6719 GO32 memory extender.
6721 * New remote protocols
6723 MIPS remote debugging protocol.
6725 * New source languages supported
6727 This version includes preliminary support for Chill, a Pascal like language
6728 used by telecommunications companies. Chill support is also being integrated
6729 into the GNU compiler, but we don't know when it will be publically available.
6732 *** Changes in GDB-4.8:
6734 * HP Precision Architecture supported
6736 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6737 version of this support was available as a set of patches from the
6738 University of Utah. GDB does not support debugging of programs
6739 compiled with the HP compiler, because HP will not document their file
6740 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6741 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6743 Many problems in the preliminary version have been fixed.
6745 * Faster and better demangling
6747 We have improved template demangling and fixed numerous bugs in the GNU style
6748 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6749 character types (wchar_t) are now supported. Demangling of each symbol is now
6750 only done once, and is cached when the symbol table for a file is read in.
6751 This results in a small increase in memory usage for C programs, a moderate
6752 increase in memory usage for C++ programs, and a fantastic speedup in
6755 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6756 from the specifications in the Annotated Reference Manual, which AT&T's
6757 compiler does not actually implement.
6759 * G++ multiple inheritance compiler problem
6761 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6762 inheritance lattices was reworked to properly discover ambiguities. We
6763 recently found an example which causes this new algorithm to fail in a
6764 very subtle way, producing bad debug information for those classes.
6765 The file 'gcc.patch' (in this directory) can be applied to gcc to
6766 circumvent the problem. A future GCC release will contain a complete
6769 The previous G++ debug info problem (mentioned below for the gdb-4.7
6770 release) is fixed in gcc version 2.3.2.
6772 * Improved configure script
6774 The `configure' script will now attempt to guess your system type if
6775 you don't supply a host system type. The old scheme of supplying a
6776 host system triplet is preferable over using this. All the magic is
6777 done in the new `config.guess' script. Examine it for details.
6779 We have also brought our configure script much more in line with the FSF's
6780 version. It now supports the --with-xxx options. In particular,
6781 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6782 The resulting GDB will not be able to read arbitrary object file formats --
6783 only the format ``expected'' to be used on the configured target system.
6784 We hope to make this the default in a future release.
6786 * Documentation improvements
6788 There's new internal documentation on how to modify GDB, and how to
6789 produce clean changes to the code. We implore people to read it
6790 before submitting changes.
6792 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6793 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6794 `info' files are also provided. To build `info' files from scratch,
6795 you will need the latest `makeinfo' release, which will be available in
6796 a future texinfo-X.Y release.
6798 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6799 We're not sure exactly which versions have this problem, but it has
6800 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6801 or better. If that isn't possible, there is a patch in
6802 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6803 around this problem.
6807 GDB now supports array constants that can be used in expressions typed in by
6808 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6809 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6812 The new directory `gdb/sparclite' contains a program that demonstrates
6813 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6815 * New native hosts supported
6817 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6818 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6820 * New targets supported
6822 AMD 29k family via UDI a29k-amd-udi or udi29k
6824 * New file formats supported
6826 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6827 HPUX core files, and SCO 3.2v2 core files.
6831 Attaching to processes now works again; thanks for the many bug reports.
6833 We have also stomped on a bunch of core dumps caused by
6834 printf_filtered("%s") problems.
6836 We eliminated a copyright problem on the rpc and ptrace header files
6837 for VxWorks, which was discovered at the last minute during the 4.7
6838 release. You should now be able to build a VxWorks GDB.
6840 You can now interrupt gdb while an attached process is running. This
6841 will cause the attached process to stop, and give control back to GDB.
6843 We fixed problems caused by using too many file descriptors
6844 for reading symbols from object files and libraries. This was
6845 especially a problem for programs that used many (~100) shared
6848 The `step' command now only enters a subroutine if there is line number
6849 information for the subroutine. Otherwise it acts like the `next'
6850 command. Previously, `step' would enter subroutines if there was
6851 any debugging information about the routine. This avoids problems
6852 when using `cc -g1' on MIPS machines.
6854 * Internal improvements
6856 GDB's internal interfaces have been improved to make it easier to support
6857 debugging of multiple languages in the future.
6859 GDB now uses a common structure for symbol information internally.
6860 Minimal symbols (derived from linkage symbols in object files), partial
6861 symbols (from a quick scan of debug information), and full symbols
6862 contain a common subset of information, making it easier to write
6863 shared code that handles any of them.
6865 * New command line options
6867 We now accept --silent as an alias for --quiet.
6871 The memory-mapped-malloc library is now licensed under the GNU Library
6872 General Public License.
6874 *** Changes in GDB-4.7:
6876 * Host/native/target split
6878 GDB has had some major internal surgery to untangle the support for
6879 hosts and remote targets. Now, when you configure GDB for a remote
6880 target, it will no longer load in all of the support for debugging
6881 local programs on the host. When fully completed and tested, this will
6882 ensure that arbitrary host/target combinations are possible.
6884 The primary conceptual shift is to separate the non-portable code in
6885 GDB into three categories. Host specific code is required any time GDB
6886 is compiled on that host, regardless of the target. Target specific
6887 code relates to the peculiarities of the target, but can be compiled on
6888 any host. Native specific code is everything else: it can only be
6889 built when the host and target are the same system. Child process
6890 handling and core file support are two common `native' examples.
6892 GDB's use of /proc for controlling Unix child processes is now cleaner.
6893 It has been split out into a single module under the `target_ops' vector,
6894 plus two native-dependent functions for each system that uses /proc.
6896 * New hosts supported
6898 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6899 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6900 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6902 * New targets supported
6904 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6905 68030 and CPU32 m68030-*-*, m68332-*-*
6907 * New native hosts supported
6909 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6910 (386bsd is not well tested yet)
6911 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6913 * New file formats supported
6915 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6916 supports reading of `a.out.adobe' object files, which are an a.out
6917 format extended with minimal information about multiple sections.
6921 `show copying' is the same as the old `info copying'.
6922 `show warranty' is the same as `info warrantee'.
6923 These were renamed for consistency. The old commands continue to work.
6925 `info handle' is a new alias for `info signals'.
6927 You can now define pre-command hooks, which attach arbitrary command
6928 scripts to any command. The commands in the hook will be executed
6929 prior to the user's command. You can also create a hook which will be
6930 executed whenever the program stops. See gdb.texinfo.
6934 We now deal with Cfront style name mangling, and can even extract type
6935 info from mangled symbols. GDB can automatically figure out which
6936 symbol mangling style your C++ compiler uses.
6938 Calling of methods and virtual functions has been improved as well.
6942 The crash that occured when debugging Sun Ansi-C compiled binaries is
6943 fixed. This was due to mishandling of the extra N_SO stabs output
6946 We also finally got Ultrix 4.2 running in house, and fixed core file
6947 support, with help from a dozen people on the net.
6949 John M. Farrell discovered that the reason that single-stepping was so
6950 slow on all of the Mips based platforms (primarily SGI and DEC) was
6951 that we were trying to demangle and lookup a symbol used for internal
6952 purposes on every instruction that was being stepped through. Changing
6953 the name of that symbol so that it couldn't be mistaken for a C++
6954 mangled symbol sped things up a great deal.
6956 Rich Pixley sped up symbol lookups in general by getting much smarter
6957 about when C++ symbol mangling is necessary. This should make symbol
6958 completion (TAB on the command line) much faster. It's not as fast as
6959 we'd like, but it's significantly faster than gdb-4.6.
6963 A new user controllable variable 'call_scratch_address' can
6964 specify the location of a scratch area to be used when GDB
6965 calls a function in the target. This is necessary because the
6966 usual method of putting the scratch area on the stack does not work
6967 in systems that have separate instruction and data spaces.
6969 We integrated changes to support the 29k UDI (Universal Debugger
6970 Interface), but discovered at the last minute that we didn't have all
6971 of the appropriate copyright paperwork. We are working with AMD to
6972 resolve this, and hope to have it available soon.
6976 We have sped up the remote serial line protocol, especially for targets
6977 with lots of registers. It now supports a new `expedited status' ('T')
6978 message which can be used in place of the existing 'S' status message.
6979 This allows the remote stub to send only the registers that GDB
6980 needs to make a quick decision about single-stepping or conditional
6981 breakpoints, eliminating the need to fetch the entire register set for
6982 each instruction being stepped through.
6984 The GDB remote serial protocol now implements a write-through cache for
6985 registers, only re-reading the registers if the target has run.
6987 There is also a new remote serial stub for SPARC processors. You can
6988 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6989 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6990 processor with a serial port.
6994 Configure.in files have become much easier to read and modify. A new
6995 `table driven' format makes it more obvious what configurations are
6996 supported, and what files each one uses.
7000 There is a new opcodes library which will eventually contain all of the
7001 disassembly routines and opcode tables. At present, it only contains
7002 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7003 disassembler (binutils/objdump) to share these routines.
7005 The libiberty library is now copylefted under the GNU Library General
7006 Public License. This allows more liberal use, and was done so libg++
7007 can use it. This makes no difference to GDB, since the Library License
7008 grants all the rights from the General Public License.
7012 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7013 reference to the stabs symbol info used by the debugger. It is (as far
7014 as we know) the only published document on this fascinating topic. We
7015 encourage you to read it, compare it to the stabs information on your
7016 system, and send improvements on the document in general (to
7017 bug-gdb@prep.ai.mit.edu).
7019 And, of course, many bugs have been fixed.
7022 *** Changes in GDB-4.6:
7024 * Better support for C++ function names
7026 GDB now accepts as input the "demangled form" of C++ overloaded function
7027 names and member function names, and can do command completion on such names
7028 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7029 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7030 Make use of command completion, it is your friend.
7032 GDB also now accepts a variety of C++ mangled symbol formats. They are
7033 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7034 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7035 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7036 for the list of formats.
7038 * G++ symbol mangling problem
7040 Recent versions of gcc have a bug in how they emit debugging information for
7041 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7042 directory) can be applied to gcc to fix the problem. Alternatively, if you
7043 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7044 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7045 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7048 * New 'maintenance' command
7050 All of the commands related to hacking GDB internals have been moved out of
7051 the main command set, and now live behind the 'maintenance' command. This
7052 can also be abbreviated as 'mt'. The following changes were made:
7054 dump-me -> maintenance dump-me
7055 info all-breakpoints -> maintenance info breakpoints
7056 printmsyms -> maintenance print msyms
7057 printobjfiles -> maintenance print objfiles
7058 printpsyms -> maintenance print psymbols
7059 printsyms -> maintenance print symbols
7061 The following commands are new:
7063 maintenance demangle Call internal GDB demangler routine to
7064 demangle a C++ link name and prints the result.
7065 maintenance print type Print a type chain for a given symbol
7067 * Change to .gdbinit file processing
7069 We now read the $HOME/.gdbinit file before processing the argv arguments
7070 (e.g. reading symbol files or core files). This allows global parameters to
7071 be set, which will apply during the symbol reading. The ./.gdbinit is still
7072 read after argv processing.
7074 * New hosts supported
7076 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7078 GNU/Linux support i386-unknown-linux or linux
7080 We are also including code to support the HP/PA running BSD and HPUX. This
7081 is almost guaranteed not to work, as we didn't have time to test or build it
7082 for this release. We are including it so that the more adventurous (or
7083 masochistic) of you can play with it. We also had major problems with the
7084 fact that the compiler that we got from HP doesn't support the -g option.
7087 * New targets supported
7089 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7091 * More smarts about finding #include files
7093 GDB now remembers the compilation directory for all include files, and for
7094 all files from which C is generated (like yacc and lex sources). This
7095 greatly improves GDB's ability to find yacc/lex sources, and include files,
7096 especially if you are debugging your program from a directory different from
7097 the one that contains your sources.
7099 We also fixed a bug which caused difficulty with listing and setting
7100 breakpoints in include files which contain C code. (In the past, you had to
7101 try twice in order to list an include file that you hadn't looked at before.)
7103 * Interesting infernals change
7105 GDB now deals with arbitrary numbers of sections, where the symbols for each
7106 section must be relocated relative to that section's landing place in the
7107 target's address space. This work was needed to support ELF with embedded
7108 stabs used by Solaris-2.0.
7110 * Bug fixes (of course!)
7112 There have been loads of fixes for the following things:
7113 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7114 i960, stabs, DOS(GO32), procfs, etc...
7116 See the ChangeLog for details.
7118 *** Changes in GDB-4.5:
7120 * New machines supported (host and target)
7122 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7124 SGI Irix-4.x mips-sgi-irix4 or iris4
7126 * New malloc package
7128 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7129 Mmalloc is capable of handling mutiple heaps of memory. It is also
7130 capable of saving a heap to a file, and then mapping it back in later.
7131 This can be used to greatly speedup the startup of GDB by using a
7132 pre-parsed symbol table which lives in a mmalloc managed heap. For
7133 more details, please read mmalloc/mmalloc.texi.
7137 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7138 'help info proc' for details.
7140 * MIPS ecoff symbol table format
7142 The code that reads MIPS symbol table format is now supported on all hosts.
7143 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7146 * File name changes for MS-DOS
7148 Many files in the config directories have been renamed to make it easier to
7149 support GDB on MS-DOSe systems (which have very restrictive file name
7150 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7151 environment) is close to working but has some remaining problems. Note
7152 that debugging of DOS programs is not supported, due to limitations
7153 in the ``operating system'', but it can be used to host cross-debugging.
7155 * Cross byte order fixes
7157 Many fixes have been made to support cross debugging of Sparc and MIPS
7158 targets from hosts whose byte order differs.
7160 * New -mapped and -readnow options
7162 If memory-mapped files are available on your system through the 'mmap'
7163 system call, you can use the -mapped option on the `file' or
7164 `symbol-file' commands to cause GDB to write the symbols from your
7165 program into a reusable file. If the program you are debugging is
7166 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7167 Future GDB debugging sessions will notice the presence of this file,
7168 and will quickly map in symbol information from it, rather than reading
7169 the symbol table from the executable program. Using the '-mapped'
7170 option in a GDB `file' or `symbol-file' command has the same effect as
7171 starting GDB with the '-mapped' command-line option.
7173 You can cause GDB to read the entire symbol table immediately by using
7174 the '-readnow' option with any of the commands that load symbol table
7175 information (or on the GDB command line). This makes the command
7176 slower, but makes future operations faster.
7178 The -mapped and -readnow options are typically combined in order to
7179 build a `fred.syms' file that contains complete symbol information.
7180 A simple GDB invocation to do nothing but build a `.syms' file for future
7183 gdb -batch -nx -mapped -readnow programname
7185 The `.syms' file is specific to the host machine on which GDB is run.
7186 It holds an exact image of GDB's internal symbol table. It cannot be
7187 shared across multiple host platforms.
7189 * longjmp() handling
7191 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7192 siglongjmp() without losing control. This feature has not yet been ported to
7193 all systems. It currently works on many 386 platforms, all MIPS-based
7194 platforms (SGI, DECstation, etc), and Sun3/4.
7198 Preliminary work has been put in to support the new Solaris OS from Sun. At
7199 this time, it can control and debug processes, but it is not capable of
7204 As always, many many bug fixes. The major areas were with g++, and mipsread.
7205 People using the MIPS-based platforms should experience fewer mysterious
7206 crashes and trashed symbol tables.
7208 *** Changes in GDB-4.4:
7210 * New machines supported (host and target)
7212 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7214 BSD Reno on Vax vax-dec-bsd
7215 Ultrix on Vax vax-dec-ultrix
7217 * New machines supported (target)
7219 AMD 29000 embedded, using EBMON a29k-none-none
7223 GDB continues to improve its handling of C++. `References' work better.
7224 The demangler has also been improved, and now deals with symbols mangled as
7225 per the Annotated C++ Reference Guide.
7227 GDB also now handles `stabs' symbol information embedded in MIPS
7228 `ecoff' symbol tables. Since the ecoff format was not easily
7229 extensible to handle new languages such as C++, this appeared to be a
7230 good way to put C++ debugging info into MIPS binaries. This option
7231 will be supported in the GNU C compiler, version 2, when it is
7234 * New features for SVR4
7236 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7237 shared libraries. Debugging dynamically linked programs should present
7238 only minor differences from debugging statically linked programs.
7240 The `info proc' command will print out information about any process
7241 on an SVR4 system (including the one you are debugging). At the moment,
7242 it prints the address mappings of the process.
7244 If you bring up GDB on another SVR4 system, please send mail to
7245 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7247 * Better dynamic linking support in SunOS
7249 Reading symbols from shared libraries which contain debugging symbols
7250 now works properly. However, there remain issues such as automatic
7251 skipping of `transfer vector' code during function calls, which
7252 make it harder to debug code in a shared library, than to debug the
7253 same code linked statically.
7257 GDB is now using the latest `getopt' routines from the FSF. This
7258 version accepts the -- prefix for options with long names. GDB will
7259 continue to accept the old forms (-option and +option) as well.
7260 Various single letter abbreviations for options have been explicity
7261 added to the option table so that they won't get overshadowed in the
7262 future by other options that begin with the same letter.
7266 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7267 Many assorted bugs have been handled. Many more remain to be handled.
7268 See the various ChangeLog files (primarily in gdb and bfd) for details.
7271 *** Changes in GDB-4.3:
7273 * New machines supported (host and target)
7275 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7276 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7277 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7279 * Almost SCO Unix support
7281 We had hoped to support:
7282 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7283 (except for core file support), but we discovered very late in the release
7284 that it has problems with process groups that render gdb unusable. Sorry
7285 about that. I encourage people to fix it and post the fixes.
7287 * Preliminary ELF and DWARF support
7289 GDB can read ELF object files on System V Release 4, and can handle
7290 debugging records for C, in DWARF format, in ELF files. This support
7291 is preliminary. If you bring up GDB on another SVR4 system, please
7292 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7297 GDB now uses the latest `readline' library. One user-visible change
7298 is that two tabs will list possible command completions, which previously
7299 required typing M-? (meta-question mark, or ESC ?).
7303 The `stepi' bug that many of you noticed has been squashed.
7304 Many bugs in C++ have been handled. Many more remain to be handled.
7305 See the various ChangeLog files (primarily in gdb and bfd) for details.
7307 * State of the MIPS world (in case you wondered):
7309 GDB can understand the symbol tables emitted by the compilers
7310 supplied by most vendors of MIPS-based machines, including DEC. These
7311 symbol tables are in a format that essentially nobody else uses.
7313 Some versions of gcc come with an assembler post-processor called
7314 mips-tfile. This program is required if you want to do source-level
7315 debugging of gcc-compiled programs. I believe FSF does not ship
7316 mips-tfile with gcc version 1, but it will eventually come with gcc
7319 Debugging of g++ output remains a problem. g++ version 1.xx does not
7320 really support it at all. (If you're lucky, you should be able to get
7321 line numbers and stack traces to work, but no parameters or local
7322 variables.) With some work it should be possible to improve the
7325 When gcc version 2 is released, you will have somewhat better luck.
7326 However, even then you will get confusing results for inheritance and
7329 We will eventually provide full debugging of g++ output on
7330 DECstations. This will probably involve some kind of stabs-in-ecoff
7331 encapulation, but the details have not been worked out yet.
7334 *** Changes in GDB-4.2:
7336 * Improved configuration
7338 Only one copy of `configure' exists now, and it is not self-modifying.
7339 Porting BFD is simpler.
7343 The `step' and `next' commands now only stop at the first instruction
7344 of a source line. This prevents the multiple stops that used to occur
7345 in switch statements, for-loops, etc. `Step' continues to stop if a
7346 function that has debugging information is called within the line.
7350 Lots of small bugs fixed. More remain.
7352 * New host supported (not target)
7354 Intel 386 PC clone running Mach i386-none-mach
7357 *** Changes in GDB-4.1:
7359 * Multiple source language support
7361 GDB now has internal scaffolding to handle several source languages.
7362 It determines the type of each source file from its filename extension,
7363 and will switch expression parsing and number formatting to match the
7364 language of the function in the currently selected stack frame.
7365 You can also specifically set the language to be used, with
7366 `set language c' or `set language modula-2'.
7370 GDB now has preliminary support for the GNU Modula-2 compiler,
7371 currently under development at the State University of New York at
7372 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7373 continue through the fall of 1991 and into 1992.
7375 Other Modula-2 compilers are currently not supported, and attempting to
7376 debug programs compiled with them will likely result in an error as the
7377 symbol table is read. Feel free to work on it, though!
7379 There are hooks in GDB for strict type checking and range checking,
7380 in the `Modula-2 philosophy', but they do not currently work.
7384 GDB can now write to executable and core files (e.g. patch
7385 a variable's value). You must turn this switch on, specify
7386 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7387 by assigning a new value to a variable. Modifications take
7390 * Automatic SunOS shared library reading
7392 When you run your program, GDB automatically determines where its
7393 shared libraries (if any) have been loaded, and reads their symbols.
7394 The `share' command is no longer needed. This also works when
7395 examining core files.
7399 You can specify the number of lines that the `list' command shows.
7402 * New machines supported (host and target)
7404 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7405 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7406 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7408 * New hosts supported (not targets)
7410 IBM RT/PC: romp-ibm-aix or rtpc
7412 * New targets supported (not hosts)
7414 AMD 29000 embedded with COFF a29k-none-coff
7415 AMD 29000 embedded with a.out a29k-none-aout
7416 Ultracomputer remote kernel debug a29k-nyu-kern
7418 * New remote interfaces
7424 *** Changes in GDB-4.0:
7428 Wide output is wrapped at good places to make the output more readable.
7430 Gdb now supports cross-debugging from a host machine of one type to a
7431 target machine of another type. Communication with the target system
7432 is over serial lines. The ``target'' command handles connecting to the
7433 remote system; the ``load'' command will download a program into the
7434 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7435 also supports debugging of realtime processes running under VxWorks,
7436 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7437 stub on the target system.
7439 New CPUs supported include the AMD 29000 and Intel 960.
7441 GDB now reads object files and symbol tables via a ``binary file''
7442 library, which allows a single copy of GDB to debug programs of multiple
7443 object file types such as a.out and coff.
7445 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7446 refcard.dvi and refcard.ps are available to format it).
7449 * Control-Variable user interface simplified
7451 All variables that control the operation of the debugger can be set
7452 by the ``set'' command, and displayed by the ``show'' command.
7454 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7455 ``Show prompt'' produces the response:
7456 Gdb's prompt is new-gdb=>.
7458 What follows are the NEW set commands. The command ``help set'' will
7459 print a complete list of old and new set commands. ``help set FOO''
7460 will give a longer description of the variable FOO. ``show'' will show
7461 all of the variable descriptions and their current settings.
7463 confirm on/off: Enables warning questions for operations that are
7464 hard to recover from, e.g. rerunning the program while
7465 it is already running. Default is ON.
7467 editing on/off: Enables EMACS style command line editing
7468 of input. Previous lines can be recalled with
7469 control-P, the current line can be edited with control-B,
7470 you can search for commands with control-R, etc.
7473 history filename NAME: NAME is where the gdb command history
7474 will be stored. The default is .gdb_history,
7475 or the value of the environment variable
7478 history size N: The size, in commands, of the command history. The
7479 default is 256, or the value of the environment variable
7482 history save on/off: If this value is set to ON, the history file will
7483 be saved after exiting gdb. If set to OFF, the
7484 file will not be saved. The default is OFF.
7486 history expansion on/off: If this value is set to ON, then csh-like
7487 history expansion will be performed on
7488 command line input. The default is OFF.
7490 radix N: Sets the default radix for input and output. It can be set
7491 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7492 in the current radix, so "set radix 10" is always a no-op.
7494 height N: This integer value is the number of lines on a page. Default
7495 is 24, the current `stty rows'' setting, or the ``li#''
7496 setting from the termcap entry matching the environment
7499 width N: This integer value is the number of characters on a line.
7500 Default is 80, the current `stty cols'' setting, or the ``co#''
7501 setting from the termcap entry matching the environment
7504 Note: ``set screensize'' is obsolete. Use ``set height'' and
7505 ``set width'' instead.
7507 print address on/off: Print memory addresses in various command displays,
7508 such as stack traces and structure values. Gdb looks
7509 more ``symbolic'' if you turn this off; it looks more
7510 ``machine level'' with it on. Default is ON.
7512 print array on/off: Prettyprint arrays. New convenient format! Default
7515 print demangle on/off: Print C++ symbols in "source" form if on,
7518 print asm-demangle on/off: Same, for assembler level printouts
7521 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7524 * Support for Epoch Environment.
7526 The epoch environment is a version of Emacs v18 with windowing. One
7527 new command, ``inspect'', is identical to ``print'', except that if you
7528 are running in the epoch environment, the value is printed in its own
7532 * Support for Shared Libraries
7534 GDB can now debug programs and core files that use SunOS shared libraries.
7535 Symbols from a shared library cannot be referenced
7536 before the shared library has been linked with the program (this
7537 happens after you type ``run'' and before the function main() is entered).
7538 At any time after this linking (including when examining core files
7539 from dynamically linked programs), gdb reads the symbols from each
7540 shared library when you type the ``sharedlibrary'' command.
7541 It can be abbreviated ``share''.
7543 sharedlibrary REGEXP: Load shared object library symbols for files
7544 matching a unix regular expression. No argument
7545 indicates to load symbols for all shared libraries.
7547 info sharedlibrary: Status of loaded shared libraries.
7552 A watchpoint stops execution of a program whenever the value of an
7553 expression changes. Checking for this slows down execution
7554 tremendously whenever you are in the scope of the expression, but is
7555 quite useful for catching tough ``bit-spreader'' or pointer misuse
7556 problems. Some machines such as the 386 have hardware for doing this
7557 more quickly, and future versions of gdb will use this hardware.
7559 watch EXP: Set a watchpoint (breakpoint) for an expression.
7561 info watchpoints: Information about your watchpoints.
7563 delete N: Deletes watchpoint number N (same as breakpoints).
7564 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7565 enable N: Re-enables watchpoint number N (same as breakpoints).
7568 * C++ multiple inheritance
7570 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7573 * C++ exception handling
7575 Gdb now supports limited C++ exception handling. Besides the existing
7576 ability to breakpoint on an exception handler, gdb can breakpoint on
7577 the raising of an exception (before the stack is peeled back to the
7580 catch FOO: If there is a FOO exception handler in the dynamic scope,
7581 set a breakpoint to catch exceptions which may be raised there.
7582 Multiple exceptions (``catch foo bar baz'') may be caught.
7584 info catch: Lists all exceptions which may be caught in the
7585 current stack frame.
7588 * Minor command changes
7590 The command ``call func (arg, arg, ...)'' now acts like the print
7591 command, except it does not print or save a value if the function's result
7592 is void. This is similar to dbx usage.
7594 The ``up'' and ``down'' commands now always print the frame they end up
7595 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7596 frames without printing.
7598 * New directory command
7600 'dir' now adds directories to the FRONT of the source search path.
7601 The path starts off empty. Source files that contain debug information
7602 about the directory in which they were compiled can be found even
7603 with an empty path; Sun CC and GCC include this information. If GDB can't
7604 find your source file in the current directory, type "dir .".
7606 * Configuring GDB for compilation
7608 For normal use, type ``./configure host''. See README or gdb.texinfo
7611 GDB now handles cross debugging. If you are remotely debugging between
7612 two different machines, type ``./configure host -target=targ''.
7613 Host is the machine where GDB will run; targ is the machine
7614 where the program that you are debugging will run.