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".
30 * The RX port now supports XML target descriptions.
32 * GDB now shows the Ada task names at more places, e.g. in task switching
35 * GDB can now be compiled with Python 3 on Windows.
39 ** The gdb.Value type has a new method 'format_string' which returns a
40 string representing the value. The formatting is controlled by the
41 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
42 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
43 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
45 ** gdb.Type has a new property 'objfile' which returns the objfile the
48 ** The frame information printed by the python frame filtering code
49 is now consistent with what the 'backtrace' command prints when
50 there are no filters, or when the 'backtrace' '-no-filters' option
53 ** The new function gdb.lookup_static_symbol can be used to look up
54 symbols with static linkage.
56 ** gdb.Objfile has new methods 'lookup_global_symbol' and
57 'lookup_static_symbol' to lookup a symbol from this objfile only.
59 ** gdb.Block now supports the dictionary syntax for accessing symbols in
60 this block (e.g. block['local_variable']).
64 | [COMMAND] | SHELL_COMMAND
65 | -d DELIM COMMAND DELIM SHELL_COMMAND
66 pipe [COMMAND] | SHELL_COMMAND
67 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
68 Executes COMMAND and sends its output to SHELL_COMMAND.
69 With no COMMAND, repeat the last executed command
70 and send its output to SHELL_COMMAND.
72 with SETTING [VALUE] [-- COMMAND]
73 w SETTING [VALUE] [-- COMMAND]
74 Temporarily set SETTING, run COMMAND, and restore SETTING.
75 Usage: with SETTING -- COMMAND
76 With no COMMAND, repeats the last executed command.
77 SETTING is any GDB setting you can change with the "set"
78 subcommands. For example, 'with language c -- print someobj'
79 temporarily switches to the C language in order to print someobj.
80 Settings can be combined: 'w lang c -- w print elements unlimited --
81 usercmd' switches to the C language and runs usercmd with no limit
82 of array elements to print.
84 maint with SETTING [VALUE] [-- COMMAND]
85 Like "with", but works with "maintenance set" settings.
87 set may-call-functions [on|off]
88 show may-call-functions
89 This controls whether GDB will attempt to call functions in
90 the program, such as with expressions in the print command. It
91 defaults to on. Calling functions in the program being debugged
92 can have undesired side effects. It is now possible to forbid
93 such function calls. If function calls are forbidden, GDB will throw
94 an error when a command (such as print expression) calls a function
97 set print finish [on|off]
99 This controls whether the `finish' command will display the value
100 that is returned by the current function. When `off', the value is
101 still entered into the value history, but it is not printed. The
106 Allows deeply nested structures to be simplified when printing by
107 replacing deeply nested parts (beyond the max-depth) with ellipses.
108 The default max-depth is 20, but this can be set to unlimited to get
109 the old behavior back.
111 set logging debugredirect [on|off]
112 By default, GDB debug output will go to both the terminal and the logfile.
113 Set if you want debug output to go only to the log file.
115 set style title foreground COLOR
116 set style title background COLOR
117 set style title intensity VALUE
118 Control the styling of titles.
120 set style highlight foreground COLOR
121 set style highlight background COLOR
122 set style highlight intensity VALUE
123 Control the styling of highlightings.
125 maint set test-settings KIND
126 maint show test-settings KIND
127 A set of commands used by the testsuite for exercising the settings
130 set print frame-info [short-location|location|location-and-address
131 |source-and-location|source-line|auto]
132 show print frame-info
133 This controls what frame information is printed by the commands printing
134 a frame. This setting will e.g. influence the behaviour of 'backtrace',
135 'frame', 'stepi'. The python frame filtering also respect this setting.
136 The 'backtrace' '-frame-info' option can override this global setting.
141 The "help" command uses the title style to enhance the
142 readibility of its output by styling the classes and
146 Similarly to "help", the "apropos" command also uses the
147 title style for the command names. "apropos" accepts now
148 a flag "-v" (verbose) to show the full documentation
149 of matching commands and to use the highlight style to mark
150 the documentation parts matching REGEXP.
154 The GDB printf and eval commands can now print C-style and Ada-style
155 string convenience variables without calling functions in the program.
156 This allows to do formatted printing of strings without having
157 a running inferior, or when debugging a core dump.
159 info sources [-dirname | -basename] [--] [REGEXP]
160 This command has now optional arguments to only print the files
161 whose names match REGEXP. The arguments -dirname and -basename
162 allow to restrict matching respectively to the dirname and basename
166 The "show style" and its subcommands are now styling
167 a style name in their output using its own style, to help
168 the user visualize the different styles.
170 set print frame-arguments
171 The new value 'presence' indicates to only indicate the presence of
172 arguments using ..., instead of printing argument names and values.
174 set print raw-frame-arguments
175 show print raw-frame-arguments
177 These commands replace the similarly-named "set/show print raw
178 frame-arguments" commands (now with a dash instead of a space). The
179 old commands are now deprecated and may be removed in a future
182 maint test-options require-delimiter
183 maint test-options unknown-is-error
184 maint test-options unknown-is-operand
185 maint show test-options-completion-result
186 Commands used by the testsuite to validate the command options
189 * New command options, command completion
191 GDB now has a standard infrastructure to support dash-style command
192 options ('-OPT'). One benefit is that commands that use it can
193 easily support completion of command line arguments. Try "CMD
194 -[TAB]" or "help CMD" to find options supported by a command. Over
195 time, we intend to migrate most commands to this infrastructure. A
196 number of commands got support for new command options in this
199 ** The "print" and "compile print" commands now support a number of
200 options that allow overriding relevant global print settings as
201 set by "set print" subcommands:
205 -array-indexes [on|off]
206 -elements NUMBER|unlimited
210 -repeats NUMBER|unlimited
211 -static-members [on|off]
216 Note that because the "print"/"compile print" commands accept
217 arbitrary expressions which may look like options (including
218 abbreviations), if you specify any command option, then you must
219 use a double dash ("--") to mark the end of argument processing.
221 ** The "backtrace" command now supports a number of options that
222 allow overriding relevant global print settings as set by "set
223 backtrace" and "set print" subcommands:
225 -entry-values no|only|preferred|if-needed|both|compact|default
226 -frame-arguments all|scalars|none
227 -raw-frame-arguments [on|off]
228 -frame-info auto|source-line|location|source-and-location
229 |location-and-address|short-location
233 In addition, the full/no-filters/hide qualifiers are now also
234 exposed as command options too:
240 ** The "frame apply", "tfaas" and "faas" commands similarly now
241 support the following options:
246 ** The new "info sources" options -dirname and -basename options
247 are using the standard '-OPT' infrastructure.
249 All options above can also be abbreviated. The argument of boolean
250 (on/off) options can be 0/1 too, and also the argument is assumed
251 "on" if omitted. This allows writing compact command invocations,
254 (gdb) p -r -p -o 0 -- *myptr
256 The above is equivalent to:
258 (gdb) print -raw -pretty -object off -- *myptr
260 ** The "info types" command now supports the '-q' flag to disable
261 printing of some header information in a similar fashion to "info
262 variables" and "info functions".
264 ** The "info variables", "info functions", and "whereis" commands
265 now take a '-n' flag that excludes non-debug symbols (symbols
266 from the symbol table, not from the debug info such as DWARF)
269 * Completion improvements
271 ** GDB can now complete the options of the "thread apply all" and
272 "taas" commands, and their "-ascending" option can now be
275 ** GDB can now complete the options of the "info threads", "info
276 functions", "info variables", "info locals", and "info args"
279 ** GDB can now complete the options of the "compile file" and
280 "compile code" commands. The "compile file" command now
281 completes on filenames.
283 ** GDB can now complete the backtrace command's
284 "full/no-filters/hide" qualifiers.
286 * In settings, you can now abbreviate "unlimited".
288 E.g., "set print elements u" is now equivalent to "set print
294 This lists all the possible completions for the rest of the line, if it
295 were to be given as a command itself. This is intended for use by MI
296 frontends in cases when separate CLI and MI channels cannot be used.
298 -catch-throw, -catch-rethrow, and -catch-catch
299 These can be used to catch C++ exceptions in a similar fashion to
300 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
304 ** Backtraces and frames include a new optional field addr_flags which is
305 given after the addr field. On AArch64 this contains PAC if the address
306 has been masked in the frame. On all other targets the field is not
311 The testsuite now creates the files gdb.cmd (containing the arguments
312 used to launch GDB) and gdb.in (containing all the commands sent to
313 GDB) in the output directory for each test script. Multiple invocations
314 are appended with .1, .2, .3 etc.
316 * Building GDB and GDBserver now requires GNU make >= 3.82.
318 Using another implementation of the make program or an earlier version of
319 GNU make to build GDB or GDBserver is not supported.
321 * Building GDB now requires GNU readline >= 7.0.
323 GDB now bundles GNU readline 8.0, but if you choose to use
324 --with-system-readline, only readline >= 7.0 can be used.
326 *** Changes in GDB 8.3
328 * GDB and GDBserver now support access to additional registers on
329 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
332 * GDB now has experimental support for the compilation and injection of
333 C++ source code into the inferior. This beta release does not include
334 support for several language features, such as templates, constructors,
337 This feature requires GCC 7.1 or higher built with libcp1.so
340 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
341 can be passed using the '[ADDRESS]:PORT' notation, or the regular
342 'ADDRESS:PORT' method.
344 * DWARF index cache: GDB can now automatically save indices of DWARF
345 symbols on disk to speed up further loading of the same binaries.
347 * Ada task switching is now supported on aarch64-elf targets when
348 debugging a program using the Ravenscar Profile. For more information,
349 see the "Tasking Support when using the Ravenscar Profile" section
350 in the GDB user manual.
352 * GDB in batch mode now exits with status 1 if the last command to be
355 * The RISC-V target now supports target descriptions.
357 * System call catchpoints now support system call aliases on FreeBSD.
358 When the ABI of a system call changes in FreeBSD, this is
359 implemented by leaving a compatibility system call using the old ABI
360 at the existing number and allocating a new system call number for
361 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
362 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
363 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
364 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
365 so that a system call catchpoint for the 'kevent' system call will
366 catch invocations of both the 'kevent' and 'freebsd11_kevent'
367 binaries. This ensures that 'kevent' system calls are caught for
368 binaries using either the old or new ABIs.
370 * Terminal styling is now available for the CLI and the TUI. GNU
371 Source Highlight can additionally be used to provide styling of
372 source code snippets. See the "set style" commands, below, for more
375 * Removed support for old demangling styles arm, edg, gnu, hp and
380 set debug compile-cplus-types
381 show debug compile-cplus-types
382 Control the display of debug output about type conversion in the
383 C++ compile feature. Commands have no effect while compiliong
388 Control whether debug output about files/functions skipping is
391 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
392 Apply a command to some frames.
393 FLAG arguments allow to control what output to produce and how to handle
394 errors raised when applying COMMAND to a frame.
397 Apply a command to all threads (ignoring errors and empty output).
398 Shortcut for 'thread apply all -s COMMAND'.
401 Apply a command to all frames (ignoring errors and empty output).
402 Shortcut for 'frame apply all -s COMMAND'.
405 Apply a command to all frames of all threads (ignoring errors and empty
407 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
409 maint set dwarf unwinders (on|off)
410 maint show dwarf unwinders
411 Control whether DWARF unwinders can be used.
414 Display a list of open files for a process.
418 Changes to the "frame", "select-frame", and "info frame" CLI commands.
419 These commands all now take a frame specification which
420 is either a frame level, or one of the keywords 'level', 'address',
421 'function', or 'view' followed by a parameter. Selecting a frame by
422 address, or viewing a frame outside the current backtrace now
423 requires the use of a keyword. Selecting a frame by level is
424 unchanged. The MI comment "-stack-select-frame" is unchanged.
426 target remote FILENAME
427 target extended-remote FILENAME
428 If FILENAME is a Unix domain socket, GDB will attempt to connect
429 to this socket instead of opening FILENAME as a character device.
431 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
432 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
433 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
434 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
435 These commands can now print only the searched entities
436 matching the provided regexp(s), giving a condition
437 on the entity names or entity types. The flag -q disables
438 printing headers or informations messages.
444 These commands now determine the syntax for the shown entities
445 according to the language chosen by `set language'. In particular,
446 `set language auto' means to automatically choose the language of
449 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
450 The 'thread apply' command accepts new FLAG arguments.
451 FLAG arguments allow to control what output to produce and how to handle
452 errors raised when applying COMMAND to a thread.
454 set tui tab-width NCHARS
455 show tui tab-width NCHARS
456 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
458 set style enabled [on|off]
460 Enable or disable terminal styling. Styling is enabled by default
461 on most hosts, but disabled by default when in batch mode.
463 set style sources [on|off]
465 Enable or disable source code styling. Source code styling is
466 enabled by default, but only takes effect if styling in general is
467 enabled, and if GDB was linked with GNU Source Highlight.
469 set style filename foreground COLOR
470 set style filename background COLOR
471 set style filename intensity VALUE
472 Control the styling of file names.
474 set style function foreground COLOR
475 set style function background COLOR
476 set style function intensity VALUE
477 Control the styling of function names.
479 set style variable foreground COLOR
480 set style variable background COLOR
481 set style variable intensity VALUE
482 Control the styling of variable names.
484 set style address foreground COLOR
485 set style address background COLOR
486 set style address intensity VALUE
487 Control the styling of addresses.
491 ** The default version of the MI interpreter is now 3 (-i=mi3).
493 ** The '-data-disassemble' MI command now accepts an '-a' option to
494 disassemble the whole function surrounding the given program
495 counter value or function name. Support for this feature can be
496 verified by using the "-list-features" command, which should
497 contain "data-disassemble-a-option".
499 ** Command responses and notifications that include a frame now include
500 the frame's architecture in a new "arch" attribute.
502 ** The output of information about multi-location breakpoints (which is
503 syntactically incorrect in MI 2) has changed in MI 3. This affects
504 the following commands and events:
508 - =breakpoint-created
509 - =breakpoint-modified
511 The -fix-multi-location-breakpoint-output command can be used to enable
512 this behavior with previous MI versions.
514 * New native configurations
516 GNU/Linux/RISC-V riscv*-*-linux*
517 FreeBSD/riscv riscv*-*-freebsd*
521 GNU/Linux/RISC-V riscv*-*-linux*
523 CSKY GNU/LINUX csky*-*-linux
524 FreeBSD/riscv riscv*-*-freebsd*
526 GNU/Linux/OpenRISC or1k*-*-linux*
530 GDB no longer supports native debugging on versions of MS-Windows
535 ** GDB no longer supports Python versions less than 2.6.
537 ** The gdb.Inferior type has a new 'progspace' property, which is the program
538 space associated to that inferior.
540 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
541 of objfiles associated to that program space.
543 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
544 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
547 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
548 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
549 correct and did not work properly.
551 ** The gdb.Value type has a new constructor, which is used to construct a
552 gdb.Value from a Python buffer object and a gdb.Type.
558 Enable or disable the undefined behavior sanitizer. This is
559 disabled by default, but passing --enable-ubsan=yes or
560 --enable-ubsan=auto to configure will enable it. Enabling this can
561 cause a performance penalty. The undefined behavior sanitizer was
562 first introduced in GCC 4.9.
564 *** Changes in GDB 8.2
566 * The 'set disassembler-options' command now supports specifying options
569 * The 'symbol-file' command now accepts an '-o' option to add a relative
570 offset to all sections.
572 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
573 a relative offset to all sections, but it allows to override the load
574 address of individual sections using '-s'.
576 * The 'add-symbol-file' command no longer requires the second argument
577 (address of the text section).
579 * The endianness used with the 'set endian auto' mode in the absence of
580 an executable selected for debugging is now the last endianness chosen
581 either by one of the 'set endian big' and 'set endian little' commands
582 or by inferring from the last executable used, rather than the startup
585 * The pager now allows a "c" response, meaning to disable the pager
586 for the rest of the current command.
588 * The commands 'info variables/functions/types' now show the source line
589 numbers of symbol definitions when available.
591 * 'info proc' now works on running processes on FreeBSD systems and core
592 files created on FreeBSD systems.
594 * C expressions can now use _Alignof, and C++ expressions can now use
597 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
598 the vector length while the process is running.
604 Control display of debugging info regarding the FreeBSD native target.
606 set|show varsize-limit
607 This new setting allows the user to control the maximum size of Ada
608 objects being printed when those objects have a variable type,
609 instead of that maximum size being hardcoded to 65536 bytes.
611 set|show record btrace cpu
612 Controls the processor to be used for enabling errata workarounds for
615 maint check libthread-db
616 Run integrity checks on the current inferior's thread debugging
619 maint set check-libthread-db (on|off)
620 maint show check-libthread-db
621 Control whether to run integrity checks on inferior specific thread
622 debugging libraries as they are loaded. The default is not to
627 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
629 ** The commands attached to a breakpoint can be set by assigning to
630 the breakpoint's "commands" field.
632 ** gdb.execute can now execute multi-line gdb commands.
634 ** The new functions gdb.convenience_variable and
635 gdb.set_convenience_variable can be used to get and set the value
636 of convenience variables.
638 ** A gdb.Parameter will no longer print the "set" help text on an
639 ordinary "set"; instead by default a "set" will be silent unless
640 the get_set_string method returns a non-empty string.
644 RiscV ELF riscv*-*-elf
646 * Removed targets and native configurations
648 m88k running OpenBSD m88*-*-openbsd*
649 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
650 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
651 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
653 * Aarch64/Linux hardware watchpoints improvements
655 Hardware watchpoints on unaligned addresses are now properly
656 supported when running Linux kernel 4.10 or higher: read and access
657 watchpoints are no longer spuriously missed, and all watchpoints
658 lengths between 1 and 8 bytes are supported. On older kernels,
659 watchpoints set on unaligned addresses are no longer missed, with
660 the tradeoff that there is a possibility of false hits being
665 --enable-codesign=CERT
666 This can be used to invoke "codesign -s CERT" after building gdb.
667 This option is useful on macOS, where code signing is required for
668 gdb to work properly.
670 --disable-gdbcli has been removed
671 This is now silently accepted, but does nothing.
673 *** Changes in GDB 8.1
675 * GDB now supports dynamically creating arbitrary register groups specified
676 in XML target descriptions. This allows for finer grain grouping of
677 registers on systems with a large amount of registers.
679 * The 'ptype' command now accepts a '/o' flag, which prints the
680 offsets and sizes of fields in a struct, like the pahole(1) tool.
682 * New "--readnever" command line option instructs GDB to not read each
683 symbol file's symbolic debug information. This makes startup faster
684 but at the expense of not being able to perform symbolic debugging.
685 This option is intended for use cases where symbolic debugging will
686 not be used, e.g., when you only need to dump the debuggee's core.
688 * GDB now uses the GNU MPFR library, if available, to emulate target
689 floating-point arithmetic during expression evaluation when the target
690 uses different floating-point formats than the host. At least version
691 3.1 of GNU MPFR is required.
693 * GDB now supports access to the guarded-storage-control registers and the
694 software-based guarded-storage broadcast control registers on IBM z14.
696 * On Unix systems, GDB now supports transmitting environment variables
697 that are to be set or unset to GDBserver. These variables will
698 affect the environment to be passed to the remote inferior.
700 To inform GDB of environment variables that are to be transmitted to
701 GDBserver, use the "set environment" command. Only user set
702 environment variables are sent to GDBserver.
704 To inform GDB of environment variables that are to be unset before
705 the remote inferior is started by the GDBserver, use the "unset
706 environment" command.
708 * Completion improvements
710 ** GDB can now complete function parameters in linespecs and
711 explicit locations without quoting. When setting breakpoints,
712 quoting around functions names to help with TAB-completion is
713 generally no longer necessary. For example, this now completes
716 (gdb) b function(in[TAB]
717 (gdb) b function(int)
719 Related, GDB is no longer confused with completing functions in
720 C++ anonymous namespaces:
723 (gdb) b (anonymous namespace)::[TAB][TAB]
724 (anonymous namespace)::a_function()
725 (anonymous namespace)::b_function()
727 ** GDB now has much improved linespec and explicit locations TAB
728 completion support, that better understands what you're
729 completing and offers better suggestions. For example, GDB no
730 longer offers data symbols as possible completions when you're
731 setting a breakpoint.
733 ** GDB now TAB-completes label symbol names.
735 ** The "complete" command now mimics TAB completion accurately.
737 * New command line options (gcore)
740 Dump all memory mappings.
742 * Breakpoints on C++ functions are now set on all scopes by default
744 By default, breakpoints on functions/methods are now interpreted as
745 specifying all functions with the given name ignoring missing
746 leading scopes (namespaces and classes).
748 For example, assuming a C++ program with symbols named:
753 both commands "break func()" and "break B::func()" set a breakpoint
756 You can use the new flag "-qualified" to override this. This makes
757 GDB interpret the specified function name as a complete
758 fully-qualified name instead. For example, using the same C++
759 program, the "break -q B::func" command sets a breakpoint on
760 "B::func", only. A parameter has been added to the Python
761 gdb.Breakpoint constructor to achieve the same result when creating
762 a breakpoint from Python.
764 * Breakpoints on functions marked with C++ ABI tags
766 GDB can now set breakpoints on functions marked with C++ ABI tags
767 (e.g., [abi:cxx11]). See here for a description of ABI tags:
768 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
770 Functions with a C++11 abi tag are demangled/displayed like this:
772 function[abi:cxx11](int)
775 You can now set a breakpoint on such functions simply as if they had
778 (gdb) b function(int)
780 Or if you need to disambiguate between tags, like:
782 (gdb) b function[abi:other_tag](int)
784 Tab completion was adjusted accordingly as well.
788 ** New events gdb.new_inferior, gdb.inferior_deleted, and
789 gdb.new_thread are emitted. See the manual for further
790 description of these.
792 ** A new function, "gdb.rbreak" has been added to the Python API.
793 This function allows the setting of a large number of breakpoints
794 via a regex pattern in Python. See the manual for further details.
796 ** Python breakpoints can now accept explicit locations. See the
797 manual for a further description of this feature.
800 * New features in the GDB remote stub, GDBserver
802 ** GDBserver is now able to start inferior processes with a
803 specified initial working directory.
805 The user can set the desired working directory to be used from
806 GDB using the new "set cwd" command.
808 ** New "--selftest" command line option runs some GDBserver self
809 tests. These self tests are disabled in releases.
811 ** On Unix systems, GDBserver now does globbing expansion and variable
812 substitution in inferior command line arguments.
814 This is done by starting inferiors using a shell, like GDB does.
815 See "set startup-with-shell" in the user manual for how to disable
816 this from GDB when using "target extended-remote". When using
817 "target remote", you can disable the startup with shell by using the
818 new "--no-startup-with-shell" GDBserver command line option.
820 ** On Unix systems, GDBserver now supports receiving environment
821 variables that are to be set or unset from GDB. These variables
822 will affect the environment to be passed to the inferior.
824 * When catching an Ada exception raised with a message, GDB now prints
825 the message in the catchpoint hit notification. In GDB/MI mode, that
826 information is provided as an extra field named "exception-message"
827 in the *stopped notification.
829 * Trait objects can now be inspected When debugging Rust code. This
830 requires compiler support which will appear in Rust 1.24.
834 QEnvironmentHexEncoded
835 Inform GDBserver of an environment variable that is to be passed to
836 the inferior when starting it.
839 Inform GDBserver of an environment variable that is to be unset
840 before starting the remote inferior.
843 Inform GDBserver that the environment should be reset (i.e.,
844 user-set environment variables should be unset).
847 Indicates whether the inferior must be started with a shell or not.
850 Tell GDBserver that the inferior to be started should use a specific
853 * The "maintenance print c-tdesc" command now takes an optional
854 argument which is the file name of XML target description.
856 * The "maintenance selftest" command now takes an optional argument to
857 filter the tests to be run.
859 * The "enable", and "disable" commands now accept a range of
860 breakpoint locations, e.g. "enable 1.3-5".
865 Set and show the current working directory for the inferior.
868 Set and show compilation command used for compiling and injecting code
869 with the 'compile' commands.
871 set debug separate-debug-file
872 show debug separate-debug-file
873 Control the display of debug output about separate debug file search.
875 set dump-excluded-mappings
876 show dump-excluded-mappings
877 Control whether mappings marked with the VM_DONTDUMP flag should be
878 dumped when generating a core file.
881 List the registered selftests.
884 Start the debugged program stopping at the first instruction.
887 Control display of debugging messages related to OpenRISC targets.
889 set|show print type nested-type-limit
890 Set and show the limit of nesting level for nested types that the
891 type printer will show.
893 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
896 * Safer/improved support for debugging with no debug info
898 GDB no longer assumes functions with no debug information return
901 This means that GDB now refuses to call such functions unless you
902 tell it the function's type, by either casting the call to the
903 declared return type, or by casting the function to a function
904 pointer of the right type, and calling that:
906 (gdb) p getenv ("PATH")
907 'getenv' has unknown return type; cast the call to its declared return type
908 (gdb) p (char *) getenv ("PATH")
909 $1 = 0x7fffffffe "/usr/local/bin:/"...
910 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
911 $2 = 0x7fffffffe "/usr/local/bin:/"...
913 Similarly, GDB no longer assumes that global variables with no debug
914 info have type 'int', and refuses to print the variable's value
915 unless you tell it the variable's type:
918 'var' has unknown type; cast it to its declared type
922 * New native configurations
924 FreeBSD/aarch64 aarch64*-*-freebsd*
925 FreeBSD/arm arm*-*-freebsd*
929 FreeBSD/aarch64 aarch64*-*-freebsd*
930 FreeBSD/arm arm*-*-freebsd*
931 OpenRISC ELF or1k*-*-elf
933 * Removed targets and native configurations
935 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
937 *** Changes in GDB 8.0
939 * GDB now supports access to the PKU register on GNU/Linux. The register is
940 added by the Memory Protection Keys for Userspace feature which will be
941 available in future Intel CPUs.
943 * GDB now supports C++11 rvalue references.
947 ** New functions to start, stop and access a running btrace recording.
948 ** Rvalue references are now supported in gdb.Type.
950 * GDB now supports recording and replaying rdrand and rdseed Intel 64
953 * Building GDB and GDBserver now requires a C++11 compiler.
955 For example, GCC 4.8 or later.
957 It is no longer possible to build GDB or GDBserver with a C
958 compiler. The --disable-build-with-cxx configure option has been
961 * Building GDB and GDBserver now requires GNU make >= 3.81.
963 It is no longer supported to build GDB or GDBserver with another
964 implementation of the make program or an earlier version of GNU make.
966 * Native debugging on MS-Windows supports command-line redirection
968 Command-line arguments used for starting programs on MS-Windows can
969 now include redirection symbols supported by native Windows shells,
970 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
971 as "run", "start", and "set args", as well as the corresponding MI
974 * Support for thread names on MS-Windows.
976 GDB now catches and handles the special exception that programs
977 running on MS-Windows use to assign names to threads in the
980 * Support for Java programs compiled with gcj has been removed.
982 * User commands now accept an unlimited number of arguments.
983 Previously, only up to 10 was accepted.
985 * The "eval" command now expands user-defined command arguments.
987 This makes it easier to process a variable number of arguments:
992 eval "print $arg%d", $i
997 * Target descriptions can now describe registers for sparc32 and sparc64.
999 * GDB now supports DWARF version 5 (debug information format).
1000 Its .debug_names index is not yet supported.
1002 * New native configurations
1004 FreeBSD/mips mips*-*-freebsd
1008 Synopsys ARC arc*-*-elf32
1009 FreeBSD/mips mips*-*-freebsd
1011 * Removed targets and native configurations
1013 Alpha running FreeBSD alpha*-*-freebsd*
1014 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1019 Erases all the flash memory regions reported by the target.
1021 maint print arc arc-instruction address
1022 Print internal disassembler information about instruction at a given address.
1026 set disassembler-options
1027 show disassembler-options
1028 Controls the passing of target specific information to the disassembler.
1029 If it is necessary to specify more than one disassembler option then
1030 multiple options can be placed together into a comma separated list.
1031 The default value is the empty string. Currently, the only supported
1032 targets are ARM, PowerPC and S/390.
1037 Erases all the flash memory regions reported by the target. This is
1038 equivalent to the CLI command flash-erase.
1040 -file-list-shared-libraries
1041 List the shared libraries in the program. This is
1042 equivalent to the CLI command "info shared".
1045 Catchpoints stopping the program when Ada exceptions are
1046 handled. This is equivalent to the CLI command "catch handlers".
1048 *** Changes in GDB 7.12
1050 * GDB and GDBserver now build with a C++ compiler by default.
1052 The --enable-build-with-cxx configure option is now enabled by
1053 default. One must now explicitly configure with
1054 --disable-build-with-cxx in order to build with a C compiler. This
1055 option will be removed in a future release.
1057 * GDBserver now supports recording btrace without maintaining an active
1060 * GDB now supports a negative repeat count in the 'x' command to examine
1061 memory backward from the given address. For example:
1064 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1065 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1066 (gdb) x/-5i 0x0000000000400580
1067 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1068 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1069 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1070 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1071 0x40057b <main(int, char**)+25>:
1072 callq 0x400536 <Func1(int, char const*)>
1074 * Fortran: Support structures with fields of dynamic types and
1075 arrays of dynamic types.
1077 * The symbol dumping maintenance commands have new syntax.
1078 maint print symbols [-pc address] [--] [filename]
1079 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1080 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1081 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1082 maint print msymbols [-objfile objfile] [--] [filename]
1084 * GDB now supports multibit bitfields and enums in target register
1087 * New Python-based convenience function $_as_string(val), which returns
1088 the textual representation of a value. This function is especially
1089 useful to obtain the text label of an enum value.
1091 * Intel MPX bound violation handling.
1093 Segmentation faults caused by a Intel MPX boundary violation
1094 now display the kind of violation (upper or lower), the memory
1095 address accessed and the memory bounds, along with the usual
1096 signal received and code location.
1100 Program received signal SIGSEGV, Segmentation fault
1101 Upper bound violation while accessing address 0x7fffffffc3b3
1102 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1103 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1105 * Rust language support.
1106 GDB now supports debugging programs written in the Rust programming
1107 language. See https://www.rust-lang.org/ for more information about
1110 * Support for running interpreters on specified input/output devices
1112 GDB now supports a new mechanism that allows frontends to provide
1113 fully featured GDB console views, as a better alternative to
1114 building such views on top of the "-interpreter-exec console"
1115 command. See the new "new-ui" command below. With that command,
1116 frontends can now start GDB in the traditional command-line mode
1117 running in an embedded terminal emulator widget, and create a
1118 separate MI interpreter running on a specified i/o device. In this
1119 way, GDB handles line editing, history, tab completion, etc. in the
1120 console all by itself, and the GUI uses the separate MI interpreter
1121 for its own control and synchronization, invisible to the command
1124 * The "catch syscall" command catches groups of related syscalls.
1126 The "catch syscall" command now supports catching a group of related
1127 syscalls using the 'group:' or 'g:' prefix.
1132 skip -gfile file-glob-pattern
1133 skip -function function
1134 skip -rfunction regular-expression
1135 A generalized form of the skip command, with new support for
1136 glob-style file names and regular expressions for function names.
1137 Additionally, a file spec and a function spec may now be combined.
1139 maint info line-table REGEXP
1140 Display the contents of GDB's internal line table data struture.
1143 Run any GDB unit tests that were compiled in.
1146 Start a new user interface instance running INTERP as interpreter,
1147 using the TTY file for input/output.
1151 ** gdb.Breakpoint objects have a new attribute "pending", which
1152 indicates whether the breakpoint is pending.
1153 ** Three new breakpoint-related events have been added:
1154 gdb.breakpoint_created, gdb.breakpoint_modified, and
1155 gdb.breakpoint_deleted.
1157 signal-event EVENTID
1158 Signal ("set") the given MS-Windows event object. This is used in
1159 conjunction with the Windows JIT debugging (AeDebug) support, where
1160 the OS suspends a crashing process until a debugger can attach to
1161 it. Resuming the crashing process, in order to debug it, is done by
1162 signalling an event.
1164 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1165 was added in GDBserver, including JIT compiling fast tracepoint's
1166 conditional expression bytecode into native code.
1168 * Support for various remote target protocols and ROM monitors has
1171 target m32rsdi Remote M32R debugging over SDI
1172 target mips MIPS remote debugging protocol
1173 target pmon PMON ROM monitor
1174 target ddb NEC's DDB variant of PMON for Vr4300
1175 target rockhopper NEC RockHopper variant of PMON
1176 target lsi LSI variant of PMO
1178 * Support for tracepoints and fast tracepoints on powerpc-linux,
1179 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1180 including JIT compiling fast tracepoint's conditional expression
1181 bytecode into native code.
1183 * MI async record =record-started now includes the method and format used for
1184 recording. For example:
1186 =record-started,thread-group="i1",method="btrace",format="bts"
1188 * MI async record =thread-selected now includes the frame field. For example:
1190 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1194 Andes NDS32 nds32*-*-elf
1196 *** Changes in GDB 7.11
1198 * GDB now supports debugging kernel-based threads on FreeBSD.
1200 * Per-inferior thread numbers
1202 Thread numbers are now per inferior instead of global. If you're
1203 debugging multiple inferiors, GDB displays thread IDs using a
1204 qualified INF_NUM.THR_NUM form. For example:
1208 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1209 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1210 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1211 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1213 As consequence, thread numbers as visible in the $_thread
1214 convenience variable and in Python's InferiorThread.num attribute
1215 are no longer unique between inferiors.
1217 GDB now maintains a second thread ID per thread, referred to as the
1218 global thread ID, which is the new equivalent of thread numbers in
1219 previous releases. See also $_gthread below.
1221 For backwards compatibility, MI's thread IDs always refer to global
1224 * Commands that accept thread IDs now accept the qualified
1225 INF_NUM.THR_NUM form as well. For example:
1228 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1231 * In commands that accept a list of thread IDs, you can now refer to
1232 all threads of an inferior using a star wildcard. GDB accepts
1233 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1234 refer to all threads of the current inferior. For example, "info
1237 * You can use "info threads -gid" to display the global thread ID of
1240 * The new convenience variable $_gthread holds the global number of
1243 * The new convenience variable $_inferior holds the number of the
1246 * GDB now displays the ID and name of the thread that hit a breakpoint
1247 or received a signal, if your program is multi-threaded. For
1250 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1251 Thread 1 "main" received signal SIGINT, Interrupt.
1253 * Record btrace now supports non-stop mode.
1255 * Support for tracepoints on aarch64-linux was added in GDBserver.
1257 * The 'record instruction-history' command now indicates speculative execution
1258 when using the Intel Processor Trace recording format.
1260 * GDB now allows users to specify explicit locations, bypassing
1261 the linespec parser. This feature is also available to GDB/MI
1264 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1265 GDB now is able to debug both AArch64 applications and ARM applications
1268 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1269 including JIT compiling fast tracepoint's conditional expression bytecode
1272 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1274 * "info threads", "info inferiors", "info display", "info checkpoints"
1275 and "maint info program-spaces" now list the corresponding items in
1276 ascending ID order, for consistency with all other "info" commands.
1278 * In Ada, the overloads selection menu has been enhanced to display the
1279 parameter types and the return types for the matching overloaded subprograms.
1283 maint set target-non-stop (on|off|auto)
1284 maint show target-non-stop
1285 Control whether GDB targets always operate in non-stop mode even if
1286 "set non-stop" is "off". The default is "auto", meaning non-stop
1287 mode is enabled if supported by the target.
1289 maint set bfd-sharing
1290 maint show bfd-sharing
1291 Control the reuse of bfd objects.
1294 show debug bfd-cache
1295 Control display of debugging info regarding bfd caching.
1299 Control display of debugging info regarding FreeBSD threads.
1301 set remote multiprocess-extensions-packet
1302 show remote multiprocess-extensions-packet
1303 Set/show the use of the remote protocol multiprocess extensions.
1305 set remote thread-events
1306 show remote thread-events
1307 Set/show the use of thread create/exit events.
1309 set ada print-signatures on|off
1310 show ada print-signatures"
1311 Control whether parameter types and return types are displayed in overloads
1312 selection menus. It is activaled (@code{on}) by default.
1316 Controls the maximum size of memory, in bytes, that GDB will
1317 allocate for value contents. Prevents incorrect programs from
1318 causing GDB to allocate overly large buffers. Default is 64k.
1320 * The "disassemble" command accepts a new modifier: /s.
1321 It prints mixed source+disassembly like /m with two differences:
1322 - disassembled instructions are now printed in program order, and
1323 - and source for all relevant files is now printed.
1324 The "/m" option is now considered deprecated: its "source-centric"
1325 output hasn't proved useful in practice.
1327 * The "record instruction-history" command accepts a new modifier: /s.
1328 It behaves exactly like /m and prints mixed source+disassembly.
1330 * The "set scheduler-locking" command supports a new mode "replay".
1331 It behaves like "off" in record mode and like "on" in replay mode.
1333 * Support for various ROM monitors has been removed:
1335 target dbug dBUG ROM monitor for Motorola ColdFire
1336 target picobug Motorola picobug monitor
1337 target dink32 DINK32 ROM monitor for PowerPC
1338 target m32r Renesas M32R/D ROM monitor
1339 target mon2000 mon2000 ROM monitor
1340 target ppcbug PPCBUG ROM monitor for PowerPC
1342 * Support for reading/writing memory and extracting values on architectures
1343 whose memory is addressable in units of any integral multiple of 8 bits.
1346 Allows to break when an Ada exception is handled.
1348 * New remote packets
1351 Indicates that an exec system call was executed.
1353 exec-events feature in qSupported
1354 The qSupported packet allows GDB to request support for exec
1355 events using the new 'gdbfeature' exec-event, and the qSupported
1356 response can contain the corresponding 'stubfeature'. Set and
1357 show commands can be used to display whether these features are enabled.
1360 Equivalent to interrupting with the ^C character, but works in
1363 thread created stop reason (T05 create:...)
1364 Indicates that the thread was just created and is stopped at entry.
1366 thread exit stop reply (w exitcode;tid)
1367 Indicates that the thread has terminated.
1370 Enables/disables thread create and exit event reporting. For
1371 example, this is used in non-stop mode when GDB stops a set of
1372 threads and synchronously waits for the their corresponding stop
1373 replies. Without exit events, if one of the threads exits, GDB
1374 would hang forever not knowing that it should no longer expect a
1375 stop for that same thread.
1378 Indicates that there are no resumed threads left in the target (all
1379 threads are stopped). The remote stub reports support for this stop
1380 reply to GDB's qSupported query.
1383 Enables/disables catching syscalls from the inferior process.
1384 The remote stub reports support for this packet to GDB's qSupported query.
1386 syscall_entry stop reason
1387 Indicates that a syscall was just called.
1389 syscall_return stop reason
1390 Indicates that a syscall just returned.
1392 * Extended-remote exec events
1394 ** GDB now has support for exec events on extended-remote Linux targets.
1395 For such targets with Linux kernels 2.5.46 and later, this enables
1396 follow-exec-mode and exec catchpoints.
1398 set remote exec-event-feature-packet
1399 show remote exec-event-feature-packet
1400 Set/show the use of the remote exec event feature.
1402 * Thread names in remote protocol
1404 The reply to qXfer:threads:read may now include a name attribute for each
1407 * Target remote mode fork and exec events
1409 ** GDB now has support for fork and exec events on target remote mode
1410 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1411 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1412 fork and exec catchpoints.
1414 * Remote syscall events
1416 ** GDB now has support for catch syscall on remote Linux targets,
1417 currently enabled on x86/x86_64 architectures.
1419 set remote catch-syscall-packet
1420 show remote catch-syscall-packet
1421 Set/show the use of the remote catch syscall feature.
1425 ** The -var-set-format command now accepts the zero-hexadecimal
1426 format. It outputs data in hexadecimal format with zero-padding on the
1431 ** gdb.InferiorThread objects have a new attribute "global_num",
1432 which refers to the thread's global thread ID. The existing
1433 "num" attribute now refers to the thread's per-inferior number.
1434 See "Per-inferior thread numbers" above.
1435 ** gdb.InferiorThread objects have a new attribute "inferior", which
1436 is the Inferior object the thread belongs to.
1438 *** Changes in GDB 7.10
1440 * Support for process record-replay and reverse debugging on aarch64*-linux*
1441 targets has been added. GDB now supports recording of A64 instruction set
1442 including advance SIMD instructions.
1444 * Support for Sun's version of the "stabs" debug file format has been removed.
1446 * GDB now honors the content of the file /proc/PID/coredump_filter
1447 (PID is the process ID) on GNU/Linux systems. This file can be used
1448 to specify the types of memory mappings that will be included in a
1449 corefile. For more information, please refer to the manual page of
1450 "core(5)". GDB also has a new command: "set use-coredump-filter
1451 on|off". It allows to set whether GDB will read the content of the
1452 /proc/PID/coredump_filter file when generating a corefile.
1454 * The "info os" command on GNU/Linux can now display information on
1456 "info os cpus" Listing of all cpus/cores on the system
1458 * GDB has two new commands: "set serial parity odd|even|none" and
1459 "show serial parity". These allows to set or show parity for the
1462 * The "info source" command now displays the producer string if it was
1463 present in the debug info. This typically includes the compiler version
1464 and may include things like its command line arguments.
1466 * The "info dll", an alias of the "info sharedlibrary" command,
1467 is now available on all platforms.
1469 * Directory names supplied to the "set sysroot" commands may be
1470 prefixed with "target:" to tell GDB to access shared libraries from
1471 the target system, be it local or remote. This replaces the prefix
1472 "remote:". The default sysroot has been changed from "" to
1473 "target:". "remote:" is automatically converted to "target:" for
1474 backward compatibility.
1476 * The system root specified by "set sysroot" will be prepended to the
1477 filename of the main executable (if reported to GDB as absolute by
1478 the operating system) when starting processes remotely, and when
1479 attaching to already-running local or remote processes.
1481 * GDB now supports automatic location and retrieval of executable
1482 files from remote targets. Remote debugging can now be initiated
1483 using only a "target remote" or "target extended-remote" command
1484 (no "set sysroot" or "file" commands are required). See "New remote
1487 * The "dump" command now supports verilog hex format.
1489 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1491 * On GNU/Linux, GDB and gdbserver are now able to access executable
1492 and shared library files without a "set sysroot" command when
1493 attaching to processes running in different mount namespaces from
1494 the debugger. This makes it possible to attach to processes in
1495 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1496 See "New remote packets" below.
1498 * The "tui reg" command now provides completion for all of the
1499 available register groups, including target specific groups.
1501 * The HISTSIZE environment variable is no longer read when determining
1502 the size of GDB's command history. GDB now instead reads the dedicated
1503 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1504 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1509 ** Memory ports can now be unbuffered.
1513 ** gdb.Objfile objects have a new attribute "username",
1514 which is the name of the objfile as specified by the user,
1515 without, for example, resolving symlinks.
1516 ** You can now write frame unwinders in Python.
1517 ** gdb.Type objects have a new method "optimized_out",
1518 returning optimized out gdb.Value instance of this type.
1519 ** gdb.Value objects have new methods "reference_value" and
1520 "const_value" which return a reference to the value and a
1521 "const" version of the value respectively.
1525 maint print symbol-cache
1526 Print the contents of the symbol cache.
1528 maint print symbol-cache-statistics
1529 Print statistics of symbol cache usage.
1531 maint flush-symbol-cache
1532 Flush the contents of the symbol cache.
1536 Start branch trace recording using Branch Trace Store (BTS) format.
1539 Evaluate expression by using the compiler and print result.
1543 Explicit commands for enabling and disabling tui mode.
1546 set mpx bound on i386 and amd64
1547 Support for bound table investigation on Intel MPX enabled applications.
1551 Start branch trace recording using Intel Processor Trace format.
1554 Print information about branch tracing internals.
1556 maint btrace packet-history
1557 Print the raw branch tracing data.
1559 maint btrace clear-packet-history
1560 Discard the stored raw branch tracing data.
1563 Discard all branch tracing data. It will be fetched and processed
1564 anew by the next "record" command.
1569 Renamed from "set debug dwarf2-die".
1570 show debug dwarf-die
1571 Renamed from "show debug dwarf2-die".
1573 set debug dwarf-read
1574 Renamed from "set debug dwarf2-read".
1575 show debug dwarf-read
1576 Renamed from "show debug dwarf2-read".
1578 maint set dwarf always-disassemble
1579 Renamed from "maint set dwarf2 always-disassemble".
1580 maint show dwarf always-disassemble
1581 Renamed from "maint show dwarf2 always-disassemble".
1583 maint set dwarf max-cache-age
1584 Renamed from "maint set dwarf2 max-cache-age".
1585 maint show dwarf max-cache-age
1586 Renamed from "maint show dwarf2 max-cache-age".
1588 set debug dwarf-line
1589 show debug dwarf-line
1590 Control display of debugging info regarding DWARF line processing.
1593 show max-completions
1594 Set the maximum number of candidates to be considered during
1595 completion. The default value is 200. This limit allows GDB
1596 to avoid generating large completion lists, the computation of
1597 which can cause the debugger to become temporarily unresponsive.
1599 set history remove-duplicates
1600 show history remove-duplicates
1601 Control the removal of duplicate history entries.
1603 maint set symbol-cache-size
1604 maint show symbol-cache-size
1605 Control the size of the symbol cache.
1607 set|show record btrace bts buffer-size
1608 Set and show the size of the ring buffer used for branch tracing in
1610 The obtained size may differ from the requested size. Use "info
1611 record" to see the obtained buffer size.
1613 set debug linux-namespaces
1614 show debug linux-namespaces
1615 Control display of debugging info regarding Linux namespaces.
1617 set|show record btrace pt buffer-size
1618 Set and show the size of the ring buffer used for branch tracing in
1619 Intel Processor Trace format.
1620 The obtained size may differ from the requested size. Use "info
1621 record" to see the obtained buffer size.
1623 maint set|show btrace pt skip-pad
1624 Set and show whether PAD packets are skipped when computing the
1627 * The command 'thread apply all' can now support new option '-ascending'
1628 to call its specified command for all threads in ascending order.
1630 * Python/Guile scripting
1632 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1633 special section named `.debug_gdb_scripts'.
1635 * New remote packets
1637 qXfer:btrace-conf:read
1638 Return the branch trace configuration for the current thread.
1640 Qbtrace-conf:bts:size
1641 Set the requested ring buffer size for branch tracing in BTS format.
1644 Enable Intel Procesor Trace-based branch tracing for the current
1645 process. The remote stub reports support for this packet to GDB's
1648 Qbtrace-conf:pt:size
1649 Set the requested ring buffer size for branch tracing in Intel Processor
1653 Indicates a memory breakpoint instruction was executed, irrespective
1654 of whether it was GDB that planted the breakpoint or the breakpoint
1655 is hardcoded in the program. This is required for correct non-stop
1659 Indicates the target stopped for a hardware breakpoint. This is
1660 required for correct non-stop mode operation.
1663 Return information about files on the remote system.
1665 qXfer:exec-file:read
1666 Return the full absolute name of the file that was executed to
1667 create a process running on the remote system.
1670 Select the filesystem on which vFile: operations with filename
1671 arguments will operate. This is required for GDB to be able to
1672 access files on remote targets where the remote stub does not
1673 share a common filesystem with the inferior(s).
1676 Indicates that a fork system call was executed.
1679 Indicates that a vfork system call was executed.
1681 vforkdone stop reason
1682 Indicates that a vfork child of the specified process has executed
1683 an exec or exit, allowing the vfork parent to resume execution.
1685 fork-events and vfork-events features in qSupported
1686 The qSupported packet allows GDB to request support for fork and
1687 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1688 and the qSupported response can contain the corresponding
1689 'stubfeatures'. Set and show commands can be used to display
1690 whether these features are enabled.
1692 * Extended-remote fork events
1694 ** GDB now has support for fork events on extended-remote Linux
1695 targets. For targets with Linux kernels 2.5.60 and later, this
1696 enables follow-fork-mode and detach-on-fork for both fork and
1697 vfork, as well as fork and vfork catchpoints.
1699 * The info record command now shows the recording format and the
1700 branch tracing configuration for the current thread when using
1701 the btrace record target.
1702 For the BTS format, it shows the ring buffer size.
1704 * GDB now has support for DTrace USDT (Userland Static Defined
1705 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1707 * GDB now supports access to vector registers on S/390 GNU/Linux
1710 * Removed command line options
1712 -xdb HP-UX XDB compatibility mode.
1714 * Removed targets and native configurations
1716 HP/PA running HP-UX hppa*-*-hpux*
1717 Itanium running HP-UX ia64-*-hpux*
1719 * New configure options
1722 This configure option allows the user to build GDB with support for
1723 Intel Processor Trace (default: auto). This requires libipt.
1725 --with-libipt-prefix=PATH
1726 Specify the path to the version of libipt that GDB should use.
1727 $PATH/include should contain the intel-pt.h header and
1728 $PATH/lib should contain the libipt.so library.
1730 *** Changes in GDB 7.9.1
1734 ** Xmethods can now specify a result type.
1736 *** Changes in GDB 7.9
1738 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1742 ** You can now access frame registers from Python scripts.
1743 ** New attribute 'producer' for gdb.Symtab objects.
1744 ** gdb.Objfile objects have a new attribute "progspace",
1745 which is the gdb.Progspace object of the containing program space.
1746 ** gdb.Objfile objects have a new attribute "owner".
1747 ** gdb.Objfile objects have a new attribute "build_id",
1748 which is the build ID generated when the file was built.
1749 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1750 ** A new event "gdb.clear_objfiles" has been added, triggered when
1751 selecting a new file to debug.
1752 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1753 ** New function gdb.lookup_objfile.
1755 New events which are triggered when GDB modifies the state of the
1758 ** gdb.events.inferior_call_pre: Function call is about to be made.
1759 ** gdb.events.inferior_call_post: Function call has just been made.
1760 ** gdb.events.memory_changed: A memory location has been altered.
1761 ** gdb.events.register_changed: A register has been altered.
1763 * New Python-based convenience functions:
1765 ** $_caller_is(name [, number_of_frames])
1766 ** $_caller_matches(regexp [, number_of_frames])
1767 ** $_any_caller_is(name [, number_of_frames])
1768 ** $_any_caller_matches(regexp [, number_of_frames])
1770 * GDB now supports the compilation and injection of source code into
1771 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1772 to compile the source code to object code, and if successful, inject
1773 and execute that code within the current context of the inferior.
1774 Currently the C language is supported. The commands used to
1775 interface with this new feature are:
1777 compile code [-raw|-r] [--] [source code]
1778 compile file [-raw|-r] filename
1782 demangle [-l language] [--] name
1783 Demangle "name" in the specified language, or the current language
1784 if elided. This command is renamed from the "maint demangle" command.
1785 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1786 as "maint demangler-warning".
1788 queue-signal signal-name-or-number
1789 Queue a signal to be delivered to the thread when it is resumed.
1791 add-auto-load-scripts-directory directory
1792 Add entries to the list of directories from which to load auto-loaded
1795 maint print user-registers
1796 List all currently available "user" registers.
1798 compile code [-r|-raw] [--] [source code]
1799 Compile, inject, and execute in the inferior the executable object
1800 code produced by compiling the provided source code.
1802 compile file [-r|-raw] filename
1803 Compile and inject into the inferior the executable object code
1804 produced by compiling the source code stored in the filename
1807 * On resume, GDB now always passes the signal the program had stopped
1808 for to the thread the signal was sent to, even if the user changed
1809 threads before resuming. Previously GDB would often (but not
1810 always) deliver the signal to the thread that happens to be current
1813 * Conversely, the "signal" command now consistently delivers the
1814 requested signal to the current thread. GDB now asks for
1815 confirmation if the program had stopped for a signal and the user
1816 switched threads meanwhile.
1818 * "breakpoint always-inserted" modes "off" and "auto" merged.
1820 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1821 won't remove breakpoints from the target until all threads stop,
1822 even in non-stop mode. The "auto" mode has been removed, and "off"
1823 is now the default mode.
1827 set debug symbol-lookup
1828 show debug symbol-lookup
1829 Control display of debugging info regarding symbol lookup.
1833 ** The -list-thread-groups command outputs an exit-code field for
1834 inferiors that have exited.
1838 MIPS SDE mips*-sde*-elf*
1842 Support for these obsolete configurations has been removed.
1844 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1845 SGI Irix-5.x mips-*-irix5*
1846 SGI Irix-6.x mips-*-irix6*
1847 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1848 VAX running Ultrix vax-*-ultrix*
1850 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1851 and "assf"), have been removed. Use the "sharedlibrary" command, or
1852 its alias "share", instead.
1854 *** Changes in GDB 7.8
1856 * New command line options
1859 This is an alias for the --data-directory option.
1861 * GDB supports printing and modifying of variable length automatic arrays
1862 as specified in ISO C99.
1864 * The ARM simulator now supports instruction level tracing
1865 with or without disassembly.
1869 GDB now has support for scripting using Guile. Whether this is
1870 available is determined at configure time.
1871 Guile version 2.0 or greater is required.
1872 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1874 * New commands (for set/show, see "New options" below)
1878 Invoke CODE by passing it to the Guile interpreter.
1882 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1884 info auto-load guile-scripts [regexp]
1885 Print the list of automatically loaded Guile scripts.
1887 * The source command is now capable of sourcing Guile scripts.
1888 This feature is dependent on the debugger being built with Guile support.
1892 set print symbol-loading (off|brief|full)
1893 show print symbol-loading
1894 Control whether to print informational messages when loading symbol
1895 information for a file. The default is "full", but when debugging
1896 programs with large numbers of shared libraries the amount of output
1897 becomes less useful.
1899 set guile print-stack (none|message|full)
1900 show guile print-stack
1901 Show a stack trace when an error is encountered in a Guile script.
1903 set auto-load guile-scripts (on|off)
1904 show auto-load guile-scripts
1905 Control auto-loading of Guile script files.
1907 maint ada set ignore-descriptive-types (on|off)
1908 maint ada show ignore-descriptive-types
1909 Control whether the debugger should ignore descriptive types in Ada
1910 programs. The default is not to ignore the descriptive types. See
1911 the user manual for more details on descriptive types and the intended
1912 usage of this option.
1914 set auto-connect-native-target
1916 Control whether GDB is allowed to automatically connect to the
1917 native target for the run, attach, etc. commands when not connected
1918 to any target yet. See also "target native" below.
1920 set record btrace replay-memory-access (read-only|read-write)
1921 show record btrace replay-memory-access
1922 Control what memory accesses are allowed during replay.
1924 maint set target-async (on|off)
1925 maint show target-async
1926 This controls whether GDB targets operate in synchronous or
1927 asynchronous mode. Normally the default is asynchronous, if it is
1928 available; but this can be changed to more easily debug problems
1929 occurring only in synchronous mode.
1931 set mi-async (on|off)
1933 Control whether MI asynchronous mode is preferred. This supersedes
1934 "set target-async" of previous GDB versions.
1936 * "set target-async" is deprecated as a CLI option and is now an alias
1937 for "set mi-async" (only puts MI into async mode).
1939 * Background execution commands (e.g., "c&", "s&", etc.) are now
1940 possible ``out of the box'' if the target supports them. Previously
1941 the user would need to explicitly enable the possibility with the
1942 "set target-async on" command.
1944 * New features in the GDB remote stub, GDBserver
1946 ** New option --debug-format=option1[,option2,...] allows one to add
1947 additional text to each output. At present only timestamps
1948 are supported: --debug-format=timestamps.
1949 Timestamps can also be turned on with the
1950 "monitor set debug-format timestamps" command from GDB.
1952 * The 'record instruction-history' command now starts counting instructions
1953 at one. This also affects the instruction ranges reported by the
1954 'record function-call-history' command when given the /i modifier.
1956 * The command 'record function-call-history' supports a new modifier '/c' to
1957 indent the function names based on their call stack depth.
1958 The fields for the '/i' and '/l' modifier have been reordered.
1959 The source line range is now prefixed with 'at'.
1960 The instruction range is now prefixed with 'inst'.
1961 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1962 "record instruction-history" and "list" commands.
1964 * The ranges given as arguments to the 'record function-call-history' and
1965 'record instruction-history' commands are now inclusive.
1967 * The btrace record target now supports the 'record goto' command.
1968 For locations inside the execution trace, the back trace is computed
1969 based on the information stored in the execution trace.
1971 * The btrace record target supports limited reverse execution and replay.
1972 The target does not record data and therefore does not allow reading
1973 memory or registers.
1975 * The "catch syscall" command now works on s390*-linux* targets.
1977 * The "compare-sections" command is no longer specific to target
1978 remote. It now works with all targets.
1980 * All native targets are now consistently called "native".
1981 Consequently, the "target child", "target GNU", "target djgpp",
1982 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1983 commands have been replaced with "target native". The QNX/NTO port
1984 leaves the "procfs" target in place and adds a "native" target for
1985 consistency with other ports. The impact on users should be minimal
1986 as these commands previously either throwed an error, or were
1987 no-ops. The target's name is visible in the output of the following
1988 commands: "help target", "info target", "info files", "maint print
1991 * The "target native" command now connects to the native target. This
1992 can be used to launch native programs even when "set
1993 auto-connect-native-target" is set to off.
1995 * GDB now supports access to Intel MPX registers on GNU/Linux.
1997 * Support for Intel AVX-512 registers on GNU/Linux.
1998 Support displaying and modifying Intel AVX-512 registers
1999 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2001 * New remote packets
2003 qXfer:btrace:read's annex
2004 The qXfer:btrace:read packet supports a new annex 'delta' to read
2005 branch trace incrementally.
2009 ** Valid Python operations on gdb.Value objects representing
2010 structs/classes invoke the corresponding overloaded operators if
2012 ** New `Xmethods' feature in the Python API. Xmethods are
2013 additional methods or replacements for existing methods of a C++
2014 class. This feature is useful for those cases where a method
2015 defined in C++ source code could be inlined or optimized out by
2016 the compiler, making it unavailable to GDB.
2019 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2021 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2022 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2023 its alias "share", instead.
2025 * The commands "set remotebaud" and "show remotebaud" are no longer
2026 supported. Use "set serial baud" and "show serial baud" (respectively)
2031 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2032 target-async". The latter is left as a deprecated alias of the
2033 former for backward compatibility. If the target supports it,
2034 CLI background execution commands are now always possible by
2035 default, independently of whether the frontend stated a
2036 preference for asynchronous execution with "-gdb-set mi-async".
2037 Previously "-gdb-set target-async off" affected both MI execution
2038 commands and CLI execution commands.
2040 *** Changes in GDB 7.7
2042 * Improved support for process record-replay and reverse debugging on
2043 arm*-linux* targets. Support for thumb32 and syscall instruction
2044 recording has been added.
2046 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2048 * GDB now supports Fission DWP file format version 2.
2049 http://gcc.gnu.org/wiki/DebugFission
2051 * New convenience function "$_isvoid", to check whether an expression
2052 is void. A void expression is an expression where the type of the
2053 result is "void". For example, some convenience variables may be
2054 "void" when evaluated (e.g., "$_exitcode" before the execution of
2055 the program being debugged; or an undefined convenience variable).
2056 Another example, when calling a function whose return type is
2059 * The "maintenance print objfiles" command now takes an optional regexp.
2061 * The "catch syscall" command now works on arm*-linux* targets.
2063 * GDB now consistently shows "<not saved>" when printing values of
2064 registers the debug info indicates have not been saved in the frame
2065 and there's nowhere to retrieve them from
2066 (callee-saved/call-clobbered registers):
2071 (gdb) info registers rax
2074 Before, the former would print "<optimized out>", and the latter
2075 "*value not available*".
2077 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2082 ** Frame filters and frame decorators have been added.
2083 ** Temporary breakpoints are now supported.
2084 ** Line tables representation has been added.
2085 ** New attribute 'parent_type' for gdb.Field objects.
2086 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2087 ** New attribute 'name' for gdb.Type objects.
2091 Nios II ELF nios2*-*-elf
2092 Nios II GNU/Linux nios2*-*-linux
2093 Texas Instruments MSP430 msp430*-*-elf
2095 * Removed native configurations
2097 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2098 been removed. ELF variants of these configurations are kept supported.
2100 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2101 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2102 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2103 i[34567]86-*-openbsd3.[0-3]
2104 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2105 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2106 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2110 Like "catch throw", but catches a re-thrown exception.
2111 maint check-psymtabs
2112 Renamed from old "maint check-symtabs".
2114 Perform consistency checks on symtabs.
2115 maint expand-symtabs
2116 Expand symtabs matching an optional regexp.
2119 Display the details of GDB configure-time options.
2121 maint set|show per-command
2122 maint set|show per-command space
2123 maint set|show per-command time
2124 maint set|show per-command symtab
2125 Enable display of per-command gdb resource usage.
2127 remove-symbol-file FILENAME
2128 remove-symbol-file -a ADDRESS
2129 Remove a symbol file added via add-symbol-file. The file to remove
2130 can be identified by its filename or by an address that lies within
2131 the boundaries of this symbol file in memory.
2134 info exceptions REGEXP
2135 Display the list of Ada exceptions defined in the program being
2136 debugged. If provided, only the exceptions whose names match REGEXP
2141 set debug symfile off|on
2143 Control display of debugging info regarding reading symbol files and
2144 symbol tables within those files
2146 set print raw frame-arguments
2147 show print raw frame-arguments
2148 Set/show whether to print frame arguments in raw mode,
2149 disregarding any defined pretty-printers.
2151 set remote trace-status-packet
2152 show remote trace-status-packet
2153 Set/show the use of remote protocol qTStatus packet.
2157 Control display of debugging messages related to Nios II targets.
2161 Control whether target-assisted range stepping is enabled.
2163 set startup-with-shell
2164 show startup-with-shell
2165 Specifies whether Unix child processes are started via a shell or
2170 Use the target memory cache for accesses to the code segment. This
2171 improves performance of remote debugging (particularly disassembly).
2173 * You can now use a literal value 'unlimited' for options that
2174 interpret 0 or -1 as meaning "unlimited". E.g., "set
2175 trace-buffer-size unlimited" is now an alias for "set
2176 trace-buffer-size -1" and "set height unlimited" is now an alias for
2179 * The "set debug symtab-create" debugging option of GDB has been changed to
2180 accept a verbosity level. 0 means "off", 1 provides basic debugging
2181 output, and values of 2 or greater provides more verbose output.
2183 * New command-line options
2185 Display the details of GDB configure-time options.
2187 * The command 'tsave' can now support new option '-ctf' to save trace
2188 buffer in Common Trace Format.
2190 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2193 * GDB now implements the the C++ 'typeid' operator.
2195 * The new convenience variable $_exception holds the exception being
2196 thrown or caught at an exception-related catchpoint.
2198 * The exception-related catchpoints, like "catch throw", now accept a
2199 regular expression which can be used to filter exceptions by type.
2201 * The new convenience variable $_exitsignal is automatically set to
2202 the terminating signal number when the program being debugged dies
2203 due to an uncaught signal.
2207 ** All MI commands now accept an optional "--language" option.
2208 Support for this feature can be verified by using the "-list-features"
2209 command, which should contain "language-option".
2211 ** The new command -info-gdb-mi-command allows the user to determine
2212 whether a GDB/MI command is supported or not.
2214 ** The "^error" result record returned when trying to execute an undefined
2215 GDB/MI command now provides a variable named "code" whose content is the
2216 "undefined-command" error code. Support for this feature can be verified
2217 by using the "-list-features" command, which should contain
2218 "undefined-command-error-code".
2220 ** The -trace-save MI command can optionally save trace buffer in Common
2223 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2225 ** The command -data-list-register-values now accepts an optional
2226 "--skip-unavailable" option. When used, only the available registers
2229 ** The new command -trace-frame-collected dumps collected variables,
2230 computed expressions, tvars, memory and registers in a traceframe.
2232 ** The commands -stack-list-locals, -stack-list-arguments and
2233 -stack-list-variables now accept an option "--skip-unavailable".
2234 When used, only the available locals or arguments are displayed.
2236 ** The -exec-run command now accepts an optional "--start" option.
2237 When used, the command follows the same semantics as the "start"
2238 command, stopping the program's execution at the start of its
2239 main subprogram. Support for this feature can be verified using
2240 the "-list-features" command, which should contain
2241 "exec-run-start-option".
2243 ** The new commands -catch-assert and -catch-exceptions insert
2244 catchpoints stopping the program when Ada exceptions are raised.
2246 ** The new command -info-ada-exceptions provides the equivalent of
2247 the new "info exceptions" command.
2249 * New system-wide configuration scripts
2250 A GDB installation now provides scripts suitable for use as system-wide
2251 configuration scripts for the following systems:
2255 * GDB now supports target-assigned range stepping with remote targets.
2256 This improves the performance of stepping source lines by reducing
2257 the number of control packets from/to GDB. See "New remote packets"
2260 * GDB now understands the element 'tvar' in the XML traceframe info.
2261 It has the id of the collected trace state variables.
2263 * On S/390 targets that provide the transactional-execution feature,
2264 the program interruption transaction diagnostic block (TDB) is now
2265 represented as a number of additional "registers" in GDB.
2267 * New remote packets
2271 The vCont packet supports a new 'r' action, that tells the remote
2272 stub to step through an address range itself, without GDB
2273 involvemement at each single-step.
2275 qXfer:libraries-svr4:read's annex
2276 The previously unused annex of the qXfer:libraries-svr4:read packet
2277 is now used to support passing an argument list. The remote stub
2278 reports support for this argument list to GDB's qSupported query.
2279 The defined arguments are "start" and "prev", used to reduce work
2280 necessary for library list updating, resulting in significant
2283 * New features in the GDB remote stub, GDBserver
2285 ** GDBserver now supports target-assisted range stepping. Currently
2286 enabled on x86/x86_64 GNU/Linux targets.
2288 ** GDBserver now adds element 'tvar' in the XML in the reply to
2289 'qXfer:traceframe-info:read'. It has the id of the collected
2290 trace state variables.
2292 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2295 * New 'z' formatter for printing and examining memory, this displays the
2296 value as hexadecimal zero padded on the left to the size of the type.
2298 * GDB can now use Windows x64 unwinding data.
2300 * The "set remotebaud" command has been replaced by "set serial baud".
2301 Similarly, "show remotebaud" has been replaced by "show serial baud".
2302 The "set remotebaud" and "show remotebaud" commands are still available
2303 to provide backward compatibility with older versions of GDB.
2305 *** Changes in GDB 7.6
2307 * Target record has been renamed to record-full.
2308 Record/replay is now enabled with the "record full" command.
2309 This also affects settings that are associated with full record/replay
2310 that have been moved from "set/show record" to "set/show record full":
2312 set|show record full insn-number-max
2313 set|show record full stop-at-limit
2314 set|show record full memory-query
2316 * A new record target "record-btrace" has been added. The new target
2317 uses hardware support to record the control-flow of a process. It
2318 does not support replaying the execution, but it implements the
2319 below new commands for investigating the recorded execution log.
2320 This new recording method can be enabled using:
2324 The "record-btrace" target is only available on Intel Atom processors
2325 and requires a Linux kernel 2.6.32 or later.
2327 * Two new commands have been added for record/replay to give information
2328 about the recorded execution without having to replay the execution.
2329 The commands are only supported by "record btrace".
2331 record instruction-history prints the execution history at
2332 instruction granularity
2334 record function-call-history prints the execution history at
2335 function granularity
2337 * New native configurations
2339 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2340 FreeBSD/powerpc powerpc*-*-freebsd
2341 x86_64/Cygwin x86_64-*-cygwin*
2342 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2346 ARM AArch64 aarch64*-*-elf
2347 ARM AArch64 GNU/Linux aarch64*-*-linux
2348 Lynx 178 PowerPC powerpc-*-lynx*178
2349 x86_64/Cygwin x86_64-*-cygwin*
2350 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2352 * If the configured location of system.gdbinit file (as given by the
2353 --with-system-gdbinit option at configure time) is in the
2354 data-directory (as specified by --with-gdb-datadir at configure
2355 time) or in one of its subdirectories, then GDB will look for the
2356 system-wide init file in the directory specified by the
2357 --data-directory command-line option.
2359 * New command line options:
2361 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2362 other initialization files, unlike -nx which disables all of them.
2364 * Removed command line options
2366 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2369 * The 'ptype' and 'whatis' commands now accept an argument to control
2372 * 'info proc' now works on some core files.
2376 ** Vectors can be created with gdb.Type.vector.
2378 ** Python's atexit.register now works in GDB.
2380 ** Types can be pretty-printed via a Python API.
2382 ** Python 3 is now supported (in addition to Python 2.4 or later)
2384 ** New class gdb.Architecture exposes GDB's internal representation
2385 of architecture in the Python API.
2387 ** New method Frame.architecture returns the gdb.Architecture object
2388 corresponding to the frame's architecture.
2390 * New Python-based convenience functions:
2392 ** $_memeq(buf1, buf2, length)
2393 ** $_streq(str1, str2)
2395 ** $_regex(str, regex)
2397 * The 'cd' command now defaults to using '~' (the home directory) if not
2400 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2401 default for GCC since November 2000.
2403 * The command 'forward-search' can now be abbreviated as 'fo'.
2405 * The command 'info tracepoints' can now display 'installed on target'
2406 or 'not installed on target' for each non-pending location of tracepoint.
2408 * New configure options
2410 --enable-libmcheck/--disable-libmcheck
2411 By default, development versions are built with -lmcheck on hosts
2412 that support it, in order to help track memory corruption issues.
2413 Release versions, on the other hand, are built without -lmcheck
2414 by default. The --enable-libmcheck/--disable-libmcheck configure
2415 options allow the user to override that default.
2416 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2417 This configure option allows the user to build GDB with
2418 libbabeltrace using which GDB can read Common Trace Format data.
2420 * New commands (for set/show, see "New options" below)
2423 Catch signals. This is similar to "handle", but allows commands and
2424 conditions to be attached.
2427 List the BFDs known to GDB.
2429 python-interactive [command]
2431 Start a Python interactive prompt, or evaluate the optional command
2432 and print the result of expressions.
2435 "py" is a new alias for "python".
2437 enable type-printer [name]...
2438 disable type-printer [name]...
2439 Enable or disable type printers.
2443 ** For the Renesas Super-H architecture, the "regs" command has been removed
2444 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2449 set print type methods (on|off)
2450 show print type methods
2451 Control whether method declarations are displayed by "ptype".
2452 The default is to show them.
2454 set print type typedefs (on|off)
2455 show print type typedefs
2456 Control whether typedef definitions are displayed by "ptype".
2457 The default is to show them.
2459 set filename-display basename|relative|absolute
2460 show filename-display
2461 Control the way in which filenames is displayed.
2462 The default is "relative", which preserves previous behavior.
2464 set trace-buffer-size
2465 show trace-buffer-size
2466 Request target to change the size of trace buffer.
2468 set remote trace-buffer-size-packet auto|on|off
2469 show remote trace-buffer-size-packet
2470 Control the use of the remote protocol `QTBuffer:size' packet.
2474 Control display of debugging messages related to ARM AArch64.
2477 set debug coff-pe-read
2478 show debug coff-pe-read
2479 Control display of debugging messages related to reading of COFF/PE
2484 Control display of debugging messages related to Mach-O symbols
2487 set debug notification
2488 show debug notification
2489 Control display of debugging info for async remote notification.
2493 ** Command parameter changes are now notified using new async record
2494 "=cmd-param-changed".
2495 ** Trace frame changes caused by command "tfind" are now notified using
2496 new async record "=traceframe-changed".
2497 ** The creation, deletion and modification of trace state variables
2498 are now notified using new async records "=tsv-created",
2499 "=tsv-deleted" and "=tsv-modified".
2500 ** The start and stop of process record are now notified using new
2501 async record "=record-started" and "=record-stopped".
2502 ** Memory changes are now notified using new async record
2504 ** The data-disassemble command response will include a "fullname" field
2505 containing the absolute file name when source has been requested.
2506 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2507 command, to allow pattern filling of memory areas.
2508 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2509 library load/unload events.
2510 ** The response to breakpoint commands and breakpoint async records
2511 includes an "installed" field containing a boolean state about each
2512 non-pending tracepoint location is whether installed on target or not.
2513 ** Output of the "-trace-status" command includes a "trace-file" field
2514 containing the name of the trace file being examined. This field is
2515 optional, and only present when examining a trace file.
2516 ** The "fullname" field is now always present along with the "file" field,
2517 even if the file cannot be found by GDB.
2519 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2520 You must have the LZMA library available when configuring GDB for this
2521 feature to be enabled. For more information, see:
2522 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2524 * New remote packets
2527 Set the size of trace buffer. The remote stub reports support for this
2528 packet to gdb's qSupported query.
2531 Enable Branch Trace Store (BTS)-based branch tracing for the current
2532 thread. The remote stub reports support for this packet to gdb's
2536 Disable branch tracing for the current thread. The remote stub reports
2537 support for this packet to gdb's qSupported query.
2540 Read the traced branches for the current thread. The remote stub
2541 reports support for this packet to gdb's qSupported query.
2543 *** Changes in GDB 7.5
2545 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2546 for more x32 ABI info.
2548 * GDB now supports access to MIPS DSP registers on Linux targets.
2550 * GDB now supports debugging microMIPS binaries.
2552 * The "info os" command on GNU/Linux can now display information on
2553 several new classes of objects managed by the operating system:
2554 "info os procgroups" lists process groups
2555 "info os files" lists file descriptors
2556 "info os sockets" lists internet-domain sockets
2557 "info os shm" lists shared-memory regions
2558 "info os semaphores" lists semaphores
2559 "info os msg" lists message queues
2560 "info os modules" lists loaded kernel modules
2562 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2563 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2564 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2565 options and inspect the probe arguments using the new $_probe_arg family
2566 of convenience variables. You can obtain more information about SystemTap
2567 in <http://sourceware.org/systemtap/>.
2569 * GDB now supports reversible debugging on ARM, it allows you to
2570 debug basic ARM and THUMB instructions, and provides
2571 record/replay support.
2573 * The option "symbol-reloading" has been deleted as it is no longer used.
2577 ** GDB commands implemented in Python can now be put in command class
2580 ** The "maint set python print-stack on|off" is now deleted.
2582 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2583 apply "flag enum"-style pretty-printing to any enum.
2585 ** gdb.lookup_symbol can now work when there is no current frame.
2587 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2588 the source at which the symbol was defined.
2590 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2591 method 'value'. The former indicates whether the symbol needs a
2592 frame in order to compute its value, and the latter computes the
2595 ** A new method 'referenced_value' on gdb.Value objects which can
2596 dereference pointer as well as C++ reference values.
2598 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2599 which return the global and static blocks (as gdb.Block objects),
2600 of the underlying symbol table, respectively.
2602 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2603 object associated with a PC value.
2605 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2606 of the address range occupied by code for the current source line.
2608 * Go language support.
2609 GDB now supports debugging programs written in the Go programming
2612 * GDBserver now supports stdio connections.
2613 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2615 * The binary "gdbtui" can no longer be built or installed.
2616 Use "gdb -tui" instead.
2618 * GDB will now print "flag" enums specially. A flag enum is one where
2619 all the enumerator values have no bits in common when pairwise
2620 "and"ed. When printing a value whose type is a flag enum, GDB will
2621 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2622 (gdb) print (enum E) 3
2625 * The filename part of a linespec will now match trailing components
2626 of a source file name. For example, "break gcc/expr.c:1000" will
2627 now set a breakpoint in build/gcc/expr.c, but not
2628 build/libcpp/expr.c.
2630 * The "info proc" and "generate-core-file" commands will now also
2631 work on remote targets connected to GDBserver on Linux.
2633 * The command "info catch" has been removed. It has been disabled
2634 since December 2007.
2636 * The "catch exception" and "catch assert" commands now accept
2637 a condition at the end of the command, much like the "break"
2638 command does. For instance:
2640 (gdb) catch exception Constraint_Error if Barrier = True
2642 Previously, it was possible to add a condition to such catchpoints,
2643 but it had to be done as a second step, after the catchpoint had been
2644 created, using the "condition" command.
2646 * The "info static-tracepoint-marker" command will now also work on
2647 native Linux targets with in-process agent.
2649 * GDB can now set breakpoints on inlined functions.
2651 * The .gdb_index section has been updated to include symbols for
2652 inlined functions. GDB will ignore older .gdb_index sections by
2653 default, which could cause symbol files to be loaded more slowly
2654 until their .gdb_index sections can be recreated. The new command
2655 "set use-deprecated-index-sections on" will cause GDB to use any older
2656 .gdb_index sections it finds. This will restore performance, but the
2657 ability to set breakpoints on inlined functions will be lost in symbol
2658 files with older .gdb_index sections.
2660 The .gdb_index section has also been updated to record more information
2661 about each symbol. This speeds up the "info variables", "info functions"
2662 and "info types" commands when used with programs having the .gdb_index
2663 section, as well as speeding up debugging with shared libraries using
2664 the .gdb_index section.
2666 * Ada support for GDB/MI Variable Objects has been added.
2668 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2673 ** New command -info-os is the MI equivalent of "info os".
2675 ** Output logs ("set logging" and related) now include MI output.
2679 ** "set use-deprecated-index-sections on|off"
2680 "show use-deprecated-index-sections on|off"
2681 Controls the use of deprecated .gdb_index sections.
2683 ** "catch load" and "catch unload" can be used to stop when a shared
2684 library is loaded or unloaded, respectively.
2686 ** "enable count" can be used to auto-disable a breakpoint after
2689 ** "info vtbl" can be used to show the virtual method tables for
2690 C++ and Java objects.
2692 ** "explore" and its sub commands "explore value" and "explore type"
2693 can be used to recursively explore values and types of
2694 expressions. These commands are available only if GDB is
2695 configured with '--with-python'.
2697 ** "info auto-load" shows status of all kinds of auto-loaded files,
2698 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2699 sequences of commands files, "info auto-load python-scripts"
2700 shows status of auto-loading Python script files,
2701 "info auto-load local-gdbinit" shows status of loading init file
2702 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2703 status of inferior specific thread debugging shared library loading.
2705 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2706 and "show auto-load-scripts" commands have been deprecated, use their
2707 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2708 and "show auto-load python-scripts" counterparts instead.
2710 ** "dprintf location,format,args..." creates a dynamic printf, which
2711 is basically a breakpoint that does a printf and immediately
2712 resumes your program's execution, so it is like a printf that you
2713 can insert dynamically at runtime instead of at compiletime.
2715 ** "set print symbol"
2717 Controls whether GDB attempts to display the symbol, if any,
2718 corresponding to addresses it prints. This defaults to "on", but
2719 you can set it to "off" to restore GDB's previous behavior.
2721 * Deprecated commands
2723 ** For the Renesas Super-H architecture, the "regs" command has been
2724 deprecated, and "info all-registers" should be used instead.
2728 Renesas RL78 rl78-*-elf
2729 HP OpenVMS ia64 ia64-hp-openvms*
2731 * GDBserver supports evaluation of breakpoint conditions. When
2732 support is advertised by GDBserver, GDB may be told to send the
2733 breakpoint conditions in bytecode form to GDBserver. GDBserver
2734 will only report the breakpoint trigger to GDB when its condition
2739 set mips compression
2740 show mips compression
2741 Select the compressed ISA encoding used in functions that have no symbol
2742 information available. The encoding can be set to either of:
2745 and is updated automatically from ELF file flags if available.
2747 set breakpoint condition-evaluation
2748 show breakpoint condition-evaluation
2749 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2750 GDBserver ("target"). Default option "auto" chooses the most efficient
2752 This option can improve debugger efficiency depending on the speed of the
2756 Disable auto-loading globally.
2759 Show auto-loading setting of all kinds of auto-loaded files.
2761 set auto-load gdb-scripts on|off
2762 show auto-load gdb-scripts
2763 Control auto-loading of GDB canned sequences of commands files.
2765 set auto-load python-scripts on|off
2766 show auto-load python-scripts
2767 Control auto-loading of Python script files.
2769 set auto-load local-gdbinit on|off
2770 show auto-load local-gdbinit
2771 Control loading of init file (.gdbinit) from current directory.
2773 set auto-load libthread-db on|off
2774 show auto-load libthread-db
2775 Control auto-loading of inferior specific thread debugging shared library.
2777 set auto-load scripts-directory <dir1>[:<dir2>...]
2778 show auto-load scripts-directory
2779 Set a list of directories from which to load auto-loaded scripts.
2780 Automatically loaded Python scripts and GDB scripts are located in one
2781 of the directories listed by this option.
2782 The delimiter (':' above) may differ according to the host platform.
2784 set auto-load safe-path <dir1>[:<dir2>...]
2785 show auto-load safe-path
2786 Set a list of directories from which it is safe to auto-load files.
2787 The delimiter (':' above) may differ according to the host platform.
2789 set debug auto-load on|off
2790 show debug auto-load
2791 Control display of debugging info for auto-loading the files above.
2793 set dprintf-style gdb|call|agent
2795 Control the way in which a dynamic printf is performed; "gdb"
2796 requests a GDB printf command, while "call" causes dprintf to call a
2797 function in the inferior. "agent" requests that the target agent
2798 (such as GDBserver) do the printing.
2800 set dprintf-function <expr>
2801 show dprintf-function
2802 set dprintf-channel <expr>
2803 show dprintf-channel
2804 Set the function and optional first argument to the call when using
2805 the "call" style of dynamic printf.
2807 set disconnected-dprintf on|off
2808 show disconnected-dprintf
2809 Control whether agent-style dynamic printfs continue to be in effect
2810 after GDB disconnects.
2812 * New configure options
2814 --with-auto-load-dir
2815 Configure default value for the 'set auto-load scripts-directory'
2816 setting above. It defaults to '$debugdir:$datadir/auto-load',
2817 $debugdir representing global debugging info directories (available
2818 via 'show debug-file-directory') and $datadir representing GDB's data
2819 directory (available via 'show data-directory').
2821 --with-auto-load-safe-path
2822 Configure default value for the 'set auto-load safe-path' setting
2823 above. It defaults to the --with-auto-load-dir setting.
2825 --without-auto-load-safe-path
2826 Set 'set auto-load safe-path' to '/', effectively disabling this
2829 * New remote packets
2831 z0/z1 conditional breakpoints extension
2833 The z0/z1 breakpoint insertion packets have been extended to carry
2834 a list of conditional expressions over to the remote stub depending on the
2835 condition evaluation mode. The use of this extension can be controlled
2836 via the "set remote conditional-breakpoints-packet" command.
2840 Specify the signals which the remote stub may pass to the debugged
2841 program without GDB involvement.
2843 * New command line options
2845 --init-command=FILE, -ix Like --command, -x but execute it
2846 before loading inferior.
2847 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2848 execute it before loading inferior.
2850 *** Changes in GDB 7.4
2852 * GDB now handles ambiguous linespecs more consistently; the existing
2853 FILE:LINE support has been expanded to other types of linespecs. A
2854 breakpoint will now be set on all matching locations in all
2855 inferiors, and locations will be added or removed according to
2858 * GDB now allows you to skip uninteresting functions and files when
2859 stepping with the "skip function" and "skip file" commands.
2861 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2862 and "show remote hardware-watchpoint-length-limit". These allows to
2863 set or show the maximum length limit (in bytes) of a remote
2864 target hardware watchpoint.
2866 This allows e.g. to use "unlimited" hardware watchpoints with the
2867 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2868 watchpoints are slower than real hardware watchpoints but are
2869 significantly faster than gdb software watchpoints.
2873 ** The register_pretty_printer function in module gdb.printing now takes
2874 an optional `replace' argument. If True, the new printer replaces any
2877 ** The "maint set python print-stack on|off" command has been
2878 deprecated and will be deleted in GDB 7.5.
2879 A new command: "set python print-stack none|full|message" has
2880 replaced it. Additionally, the default for "print-stack" is
2881 now "message", which just prints the error message without
2884 ** A prompt substitution hook (prompt_hook) is now available to the
2887 ** A new Python module, gdb.prompt has been added to the GDB Python
2888 modules library. This module provides functionality for
2889 escape sequences in prompts (used by set/show
2890 extended-prompt). These escape sequences are replaced by their
2891 corresponding value.
2893 ** Python commands and convenience-functions located in
2894 'data-directory'/python/gdb/command and
2895 'data-directory'/python/gdb/function are now automatically loaded
2898 ** Blocks now provide four new attributes. global_block and
2899 static_block will return the global and static blocks
2900 respectively. is_static and is_global are boolean attributes
2901 that indicate if the block is one of those two types.
2903 ** Symbols now provide the "type" attribute, the type of the symbol.
2905 ** The "gdb.breakpoint" function has been deprecated in favor of
2908 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2909 of a function. This class is based on the "finish" command
2910 available in the CLI.
2912 ** Type objects for struct and union types now allow access to
2913 the fields using standard Python dictionary (mapping) methods.
2914 For example, "some_type['myfield']" now works, as does
2915 "some_type.items()".
2917 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2920 ** A new function, "deep_items" has been added to the gdb.types
2921 module in the GDB Python modules library. This function returns
2922 an iterator over the fields of a struct or union type. Unlike
2923 the standard Python "iteritems" method, it will recursively traverse
2924 any anonymous fields.
2928 ** "*stopped" events can report several new "reason"s, such as
2931 ** Breakpoint changes are now notified using new async records, like
2932 "=breakpoint-modified".
2934 ** New command -ada-task-info.
2936 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2937 $sdir specifies the default system locations of shared libraries.
2938 $pdir specifies the directory where the libpthread used by the application
2941 GDB no longer looks in $sdir and $pdir after it has searched the directories
2942 mentioned in libthread-db-search-path. If you want to search those
2943 directories, they must be specified in libthread-db-search-path.
2944 The default value of libthread-db-search-path on GNU/Linux and Solaris
2945 systems is now "$sdir:$pdir".
2947 $pdir is not supported by gdbserver, it is currently ignored.
2948 $sdir is supported by gdbserver.
2950 * New configure option --with-iconv-bin.
2951 When using the internationalization support like the one in the GNU C
2952 library, GDB will invoke the "iconv" program to get a list of supported
2953 character sets. If this program lives in a non-standard location, one can
2954 use this option to specify where to find it.
2956 * When natively debugging programs on PowerPC BookE processors running
2957 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2958 watchpoints, which specify a mask in addition to an address to watch.
2959 The mask specifies that some bits of an address (the bits which are
2960 reset in the mask) should be ignored when matching the address accessed
2961 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2962 section in the user manual for more details.
2964 * The new option --once causes GDBserver to stop listening for connections once
2965 the first connection is made. The listening port used by GDBserver will
2966 become available after that.
2968 * New commands "info macros" and "alias" have been added.
2970 * New function parameters suffix @entry specifies value of function parameter
2971 at the time the function got called. Entry values are available only since
2977 "!" is now an alias of the "shell" command.
2978 Note that no space is needed between "!" and SHELL COMMAND.
2982 watch EXPRESSION mask MASK_VALUE
2983 The watch command now supports the mask argument which allows creation
2984 of masked watchpoints, if the current architecture supports this feature.
2986 info auto-load-scripts [REGEXP]
2987 This command was formerly named "maintenance print section-scripts".
2988 It is now generally useful and is no longer a maintenance-only command.
2990 info macro [-all] [--] MACRO
2991 The info macro command has new options `-all' and `--'. The first for
2992 printing all definitions of a macro. The second for explicitly specifying
2993 the end of arguments and the beginning of the macro name in case the macro
2994 name starts with a hyphen.
2996 collect[/s] EXPRESSIONS
2997 The tracepoint collect command now takes an optional modifier "/s"
2998 that directs it to dereference pointer-to-character types and
2999 collect the bytes of memory up to a zero byte. The behavior is
3000 similar to what you see when you use the regular print command on a
3001 string. An optional integer following the "/s" sets a bound on the
3002 number of bytes that will be collected.
3005 The trace start command now interprets any supplied arguments as a
3006 note to be recorded with the trace run, with an effect similar to
3007 setting the variable trace-notes.
3010 The trace stop command now interprets any arguments as a note to be
3011 mentioned along with the tstatus report that the trace was stopped
3012 with a command. The effect is similar to setting the variable
3015 * Tracepoints can now be enabled and disabled at any time after a trace
3016 experiment has been started using the standard "enable" and "disable"
3017 commands. It is now possible to start a trace experiment with no enabled
3018 tracepoints; GDB will display a warning, but will allow the experiment to
3019 begin, assuming that tracepoints will be enabled as needed while the trace
3022 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3023 locations with 4-byte instructions, when they were previously
3024 limited to locations with instructions of 5 bytes or longer.
3028 set debug dwarf2-read
3029 show debug dwarf2-read
3030 Turns on or off display of debugging messages related to reading
3031 DWARF debug info. The default is off.
3033 set debug symtab-create
3034 show debug symtab-create
3035 Turns on or off display of debugging messages related to symbol table
3036 creation. The default is off.
3039 show extended-prompt
3040 Set the GDB prompt, and allow escape sequences to be inserted to
3041 display miscellaneous information (see 'help set extended-prompt'
3042 for the list of sequences). This prompt (and any information
3043 accessed through the escape sequences) is updated every time the
3044 prompt is displayed.
3046 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3047 show print entry-values
3048 Set printing of frame argument values at function entry. In some cases
3049 GDB can determine the value of function argument which was passed by the
3050 function caller, even if the value was modified inside the called function.
3052 set debug entry-values
3053 show debug entry-values
3054 Control display of debugging info for determining frame argument values at
3055 function entry and virtual tail call frames.
3057 set basenames-may-differ
3058 show basenames-may-differ
3059 Set whether a source file may have multiple base names.
3060 (A "base name" is the name of a file with the directory part removed.
3061 Example: The base name of "/home/user/hello.c" is "hello.c".)
3062 If set, GDB will canonicalize file names (e.g., expand symlinks)
3063 before comparing them. Canonicalization is an expensive operation,
3064 but it allows the same file be known by more than one base name.
3065 If not set (the default), all source files are assumed to have just
3066 one base name, and gdb will do file name comparisons more efficiently.
3072 Set a user name and notes for the current and any future trace runs.
3073 This is useful for long-running and/or disconnected traces, to
3074 inform others (or yourself) as to who is running the trace, supply
3075 contact information, or otherwise explain what is going on.
3077 set trace-stop-notes
3078 show trace-stop-notes
3079 Set a note attached to the trace run, that is displayed when the
3080 trace has been stopped by a tstop command. This is useful for
3081 instance as an explanation, if you are stopping a trace run that was
3082 started by someone else.
3084 * New remote packets
3088 Dynamically enable a tracepoint in a started trace experiment.
3092 Dynamically disable a tracepoint in a started trace experiment.
3096 Set the user and notes of the trace run.
3100 Query the current status of a tracepoint.
3104 Query the minimum length of instruction at which a fast tracepoint may
3107 * Dcache size (number of lines) and line-size are now runtime-configurable
3108 via "set dcache line" and "set dcache line-size" commands.
3112 Texas Instruments TMS320C6x tic6x-*-*
3116 Renesas RL78 rl78-*-elf
3118 *** Changes in GDB 7.3.1
3120 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3122 *** Changes in GDB 7.3
3124 * GDB has a new command: "thread find [REGEXP]".
3125 It finds the thread id whose name, target id, or thread extra info
3126 matches the given regular expression.
3128 * The "catch syscall" command now works on mips*-linux* targets.
3130 * The -data-disassemble MI command now supports modes 2 and 3 for
3131 dumping the instruction opcodes.
3133 * New command line options
3135 -data-directory DIR Specify DIR as the "data-directory".
3136 This is mostly for testing purposes.
3138 * The "maint set python auto-load on|off" command has been renamed to
3139 "set auto-load-scripts on|off".
3141 * GDB has a new command: "set directories".
3142 It is like the "dir" command except that it replaces the
3143 source path list instead of augmenting it.
3145 * GDB now understands thread names.
3147 On GNU/Linux, "info threads" will display the thread name as set by
3148 prctl or pthread_setname_np.
3150 There is also a new command, "thread name", which can be used to
3151 assign a name internally for GDB to display.
3154 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3155 has been integrated into GDB.
3159 ** The function gdb.Write now accepts an optional keyword 'stream'.
3160 This keyword, when provided, will direct the output to either
3161 stdout, stderr, or GDB's logging output.
3163 ** Parameters can now be be sub-classed in Python, and in particular
3164 you may implement the get_set_doc and get_show_doc functions.
3165 This improves how Parameter set/show documentation is processed
3166 and allows for more dynamic content.
3168 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3169 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3170 have an is_valid method.
3172 ** Breakpoints can now be sub-classed in Python, and in particular
3173 you may implement a 'stop' function that is executed each time
3174 the inferior reaches that breakpoint.
3176 ** New function gdb.lookup_global_symbol looks up a global symbol.
3178 ** GDB values in Python are now callable if the value represents a
3179 function. For example, if 'some_value' represents a function that
3180 takes two integer parameters and returns a value, you can call
3181 that function like so:
3183 result = some_value (10,20)
3185 ** Module gdb.types has been added.
3186 It contains a collection of utilities for working with gdb.Types objects:
3187 get_basic_type, has_field, make_enum_dict.
3189 ** Module gdb.printing has been added.
3190 It contains utilities for writing and registering pretty-printers.
3191 New classes: PrettyPrinter, SubPrettyPrinter,
3192 RegexpCollectionPrettyPrinter.
3193 New function: register_pretty_printer.
3195 ** New commands "info pretty-printers", "enable pretty-printer" and
3196 "disable pretty-printer" have been added.
3198 ** gdb.parameter("directories") is now available.
3200 ** New function gdb.newest_frame returns the newest frame in the
3203 ** The gdb.InferiorThread class has a new "name" attribute. This
3204 holds the thread's name.
3206 ** Python Support for Inferior events.
3207 Python scripts can add observers to be notified of events
3208 occurring in the process being debugged.
3209 The following events are currently supported:
3210 - gdb.events.cont Continue event.
3211 - gdb.events.exited Inferior exited event.
3212 - gdb.events.stop Signal received, and Breakpoint hit events.
3216 ** GDB now puts template parameters in scope when debugging in an
3217 instantiation. For example, if you have:
3219 template<int X> int func (void) { return X; }
3221 then if you step into func<5>, "print X" will show "5". This
3222 feature requires proper debuginfo support from the compiler; it
3223 was added to GCC 4.5.
3225 ** The motion commands "next", "finish", "until", and "advance" now
3226 work better when exceptions are thrown. In particular, GDB will
3227 no longer lose control of the inferior; instead, the GDB will
3228 stop the inferior at the point at which the exception is caught.
3229 This functionality requires a change in the exception handling
3230 code that was introduced in GCC 4.5.
3232 * GDB now follows GCC's rules on accessing volatile objects when
3233 reading or writing target state during expression evaluation.
3234 One notable difference to prior behavior is that "print x = 0"
3235 no longer generates a read of x; the value of the assignment is
3236 now always taken directly from the value being assigned.
3238 * GDB now has some support for using labels in the program's source in
3239 linespecs. For instance, you can use "advance label" to continue
3240 execution to a label.
3242 * GDB now has support for reading and writing a new .gdb_index
3243 section. This section holds a fast index of DWARF debugging
3244 information and can be used to greatly speed up GDB startup and
3245 operation. See the documentation for `save gdb-index' for details.
3247 * The "watch" command now accepts an optional "-location" argument.
3248 When used, this causes GDB to watch the memory referred to by the
3249 expression. Such a watchpoint is never deleted due to it going out
3252 * GDB now supports thread debugging of core dumps on GNU/Linux.
3254 GDB now activates thread debugging using the libthread_db library
3255 when debugging GNU/Linux core dumps, similarly to when debugging
3256 live processes. As a result, when debugging a core dump file, GDB
3257 is now able to display pthread_t ids of threads. For example, "info
3258 threads" shows the same output as when debugging the process when it
3259 was live. In earlier releases, you'd see something like this:
3262 * 1 LWP 6780 main () at main.c:10
3264 While now you see this:
3267 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3269 It is also now possible to inspect TLS variables when debugging core
3272 When debugging a core dump generated on a machine other than the one
3273 used to run GDB, you may need to point GDB at the correct
3274 libthread_db library with the "set libthread-db-search-path"
3275 command. See the user manual for more details on this command.
3277 * When natively debugging programs on PowerPC BookE processors running
3278 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3279 which stop execution of the inferior whenever it executes an instruction
3280 at any address within the specified range. See the "PowerPC Embedded"
3281 section in the user manual for more details.
3283 * New features in the GDB remote stub, GDBserver
3285 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3286 and i686 LynxOS (version 5.x).
3288 ** GDBserver is now supported on Blackfin Linux.
3290 * New native configurations
3292 ia64 HP-UX ia64-*-hpux*
3296 Analog Devices, Inc. Blackfin Processor bfin-*
3298 * Ada task switching is now supported on sparc-elf targets when
3299 debugging a program using the Ravenscar Profile. For more information,
3300 see the "Tasking Support when using the Ravenscar Profile" section
3301 in the GDB user manual.
3303 * Guile support was removed.
3305 * New features in the GNU simulator
3307 ** The --map-info flag lists all known core mappings.
3309 ** CFI flashes may be simulated via the "cfi" device.
3311 *** Changes in GDB 7.2
3313 * Shared library support for remote targets by default
3315 When GDB is configured for a generic, non-OS specific target, like
3316 for example, --target=arm-eabi or one of the many *-*-elf targets,
3317 GDB now queries remote stubs for loaded shared libraries using the
3318 `qXfer:libraries:read' packet. Previously, shared library support
3319 was always disabled for such configurations.
3323 ** Argument Dependent Lookup (ADL)
3325 In C++ ADL lookup directs function search to the namespaces of its
3326 arguments even if the namespace has not been imported.
3336 Here the compiler will search for `foo' in the namespace of 'b'
3337 and find A::foo. GDB now supports this. This construct is commonly
3338 used in the Standard Template Library for operators.
3340 ** Improved User Defined Operator Support
3342 In addition to member operators, GDB now supports lookup of operators
3343 defined in a namespace and imported with a `using' directive, operators
3344 defined in the global scope, operators imported implicitly from an
3345 anonymous namespace, and the ADL operators mentioned in the previous
3347 GDB now also supports proper overload resolution for all the previously
3348 mentioned flavors of operators.
3350 ** static const class members
3352 Printing of static const class members that are initialized in the
3353 class definition has been fixed.
3355 * Windows Thread Information Block access.
3357 On Windows targets, GDB now supports displaying the Windows Thread
3358 Information Block (TIB) structure. This structure is visible either
3359 by using the new command `info w32 thread-information-block' or, by
3360 dereferencing the new convenience variable named `$_tlb', a
3361 thread-specific pointer to the TIB. This feature is also supported
3362 when remote debugging using GDBserver.
3364 * Static tracepoints
3366 Static tracepoints are calls in the user program into a tracing
3367 library. One such library is a port of the LTTng kernel tracer to
3368 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3369 When debugging with GDBserver, GDB now supports combining the GDB
3370 tracepoint machinery with such libraries. For example: the user can
3371 use GDB to probe a static tracepoint marker (a call from the user
3372 program into the tracing library) with the new "strace" command (see
3373 "New commands" below). This creates a "static tracepoint" in the
3374 breakpoint list, that can be manipulated with the same feature set
3375 as fast and regular tracepoints. E.g., collect registers, local and
3376 global variables, collect trace state variables, and define
3377 tracepoint conditions. In addition, the user can collect extra
3378 static tracepoint marker specific data, by collecting the new
3379 $_sdata internal variable. When analyzing the trace buffer, you can
3380 inspect $_sdata like any other variable available to GDB. For more
3381 information, see the "Tracepoints" chapter in GDB user manual. New
3382 remote packets have been defined to support static tracepoints, see
3383 the "New remote packets" section below.
3385 * Better reconstruction of tracepoints after disconnected tracing
3387 GDB will attempt to download the original source form of tracepoint
3388 definitions when starting a trace run, and then will upload these
3389 upon reconnection to the target, resulting in a more accurate
3390 reconstruction of the tracepoints that are in use on the target.
3394 You can now exercise direct control over the ways that GDB can
3395 affect your program. For instance, you can disallow the setting of
3396 breakpoints, so that the program can run continuously (assuming
3397 non-stop mode). In addition, the "observer" variable is available
3398 to switch all of the different controls; in observer mode, GDB
3399 cannot affect the target's behavior at all, which is useful for
3400 tasks like diagnosing live systems in the field.
3402 * The new convenience variable $_thread holds the number of the
3405 * New remote packets
3409 Return the address of the Windows Thread Information Block of a given thread.
3413 In response to several of the tracepoint packets, the target may now
3414 also respond with a number of intermediate `qRelocInsn' request
3415 packets before the final result packet, to have GDB handle
3416 relocating an instruction to execute at a different address. This
3417 is particularly useful for stubs that support fast tracepoints. GDB
3418 reports support for this feature in the qSupported packet.
3422 List static tracepoint markers in the target program.
3426 List static tracepoint markers at a given address in the target
3429 qXfer:statictrace:read
3431 Read the static trace data collected (by a `collect $_sdata'
3432 tracepoint action). The remote stub reports support for this packet
3433 to gdb's qSupported query.
3437 Send the current settings of GDB's permission flags.
3441 Send part of the source (textual) form of a tracepoint definition,
3442 which includes location, conditional, and action list.
3444 * The source command now accepts a -s option to force searching for the
3445 script in the source search path even if the script name specifies
3448 * New features in the GDB remote stub, GDBserver
3450 - GDBserver now support tracepoints (including fast tracepoints, and
3451 static tracepoints). The feature is currently supported by the
3452 i386-linux and amd64-linux builds. See the "Tracepoints support
3453 in gdbserver" section in the manual for more information.
3455 GDBserver JIT compiles the tracepoint's conditional agent
3456 expression bytecode into native code whenever possible for low
3457 overhead dynamic tracepoints conditionals. For such tracepoints,
3458 an expression that examines program state is evaluated when the
3459 tracepoint is reached, in order to determine whether to capture
3460 trace data. If the condition is simple and false, processing the
3461 tracepoint finishes very quickly and no data is gathered.
3463 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3464 for static tracepoints support.
3466 - GDBserver now supports x86_64 Windows 64-bit debugging.
3468 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3469 it understands register description.
3471 * The --batch flag now disables pagination and queries.
3473 * X86 general purpose registers
3475 GDB now supports reading/writing byte, word and double-word x86
3476 general purpose registers directly. This means you can use, say,
3477 $ah or $ax to refer, respectively, to the byte register AH and
3478 16-bit word register AX that are actually portions of the 32-bit
3479 register EAX or 64-bit register RAX.
3481 * The `commands' command now accepts a range of breakpoints to modify.
3482 A plain `commands' following a command that creates multiple
3483 breakpoints affects all the breakpoints set by that command. This
3484 applies to breakpoints set by `rbreak', and also applies when a
3485 single `break' command creates multiple breakpoints (e.g.,
3486 breakpoints on overloaded c++ functions).
3488 * The `rbreak' command now accepts a filename specification as part of
3489 its argument, limiting the functions selected by the regex to those
3490 in the specified file.
3492 * Support for remote debugging Windows and SymbianOS shared libraries
3493 from Unix hosts has been improved. Non Windows GDB builds now can
3494 understand target reported file names that follow MS-DOS based file
3495 system semantics, such as file names that include drive letters and
3496 use the backslash character as directory separator. This makes it
3497 possible to transparently use the "set sysroot" and "set
3498 solib-search-path" on Unix hosts to point as host copies of the
3499 target's shared libraries. See the new command "set
3500 target-file-system-kind" described below, and the "Commands to
3501 specify files" section in the user manual for more information.
3505 eval template, expressions...
3506 Convert the values of one or more expressions under the control
3507 of the string template to a command line, and call it.
3509 set target-file-system-kind unix|dos-based|auto
3510 show target-file-system-kind
3511 Set or show the assumed file system kind for target reported file
3514 save breakpoints <filename>
3515 Save all current breakpoint definitions to a file suitable for use
3516 in a later debugging session. To read the saved breakpoint
3517 definitions, use the `source' command.
3519 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3522 info static-tracepoint-markers
3523 Display information about static tracepoint markers in the target.
3525 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3526 Define a static tracepoint by probing a marker at the given
3527 function, line, address, or marker ID.
3531 Enable and disable observer mode.
3533 set may-write-registers on|off
3534 set may-write-memory on|off
3535 set may-insert-breakpoints on|off
3536 set may-insert-tracepoints on|off
3537 set may-insert-fast-tracepoints on|off
3538 set may-interrupt on|off
3539 Set individual permissions for GDB effects on the target. Note that
3540 some of these settings can have undesirable or surprising
3541 consequences, particularly when changed in the middle of a session.
3542 For instance, disabling the writing of memory can prevent
3543 breakpoints from being inserted, cause single-stepping to fail, or
3544 even crash your program, if you disable after breakpoints have been
3545 inserted. However, GDB should not crash.
3547 set record memory-query on|off
3548 show record memory-query
3549 Control whether to stop the inferior if memory changes caused
3550 by an instruction cannot be recorded.
3555 The disassemble command now supports "start,+length" form of two arguments.
3559 ** GDB now provides a new directory location, called the python directory,
3560 where Python scripts written for GDB can be installed. The location
3561 of that directory is <data-directory>/python, where <data-directory>
3562 is the GDB data directory. For more details, see section `Scripting
3563 GDB using Python' in the manual.
3565 ** The GDB Python API now has access to breakpoints, symbols, symbol
3566 tables, program spaces, inferiors, threads and frame's code blocks.
3567 Additionally, GDB Parameters can now be created from the API, and
3568 manipulated via set/show in the CLI.
3570 ** New functions gdb.target_charset, gdb.target_wide_charset,
3571 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3573 ** New exception gdb.GdbError.
3575 ** Pretty-printers are now also looked up in the current program space.
3577 ** Pretty-printers can now be individually enabled and disabled.
3579 ** GDB now looks for names of Python scripts to auto-load in a
3580 special section named `.debug_gdb_scripts', in addition to looking
3581 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3583 * Tracepoint actions were unified with breakpoint commands. In particular,
3584 there are no longer differences in "info break" output for breakpoints and
3585 tracepoints and the "commands" command can be used for both tracepoints and
3586 regular breakpoints.
3590 ARM Symbian arm*-*-symbianelf*
3592 * D language support.
3593 GDB now supports debugging programs written in the D programming
3596 * GDB now supports the extended ptrace interface for PowerPC which is
3597 available since Linux kernel version 2.6.34. This automatically enables
3598 any hardware breakpoints and additional hardware watchpoints available in
3599 the processor. The old ptrace interface exposes just one hardware
3600 watchpoint and no hardware breakpoints.
3602 * GDB is now able to use the Data Value Compare (DVC) register available on
3603 embedded PowerPC processors to implement in hardware simple watchpoint
3604 conditions of the form:
3606 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3608 This works in native GDB running on Linux kernels with the extended ptrace
3609 interface mentioned above.
3611 *** Changes in GDB 7.1
3615 ** Namespace Support
3617 GDB now supports importing of namespaces in C++. This enables the
3618 user to inspect variables from imported namespaces. Support for
3619 namepace aliasing has also been added. So, if a namespace is
3620 aliased in the current scope (e.g. namepace C=A; ) the user can
3621 print variables using the alias (e.g. (gdb) print C::x).
3625 All known bugs relating to the printing of virtual base class were
3626 fixed. It is now possible to call overloaded static methods using a
3631 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3632 and reinterpret_cast<> are now handled by the C++ expression parser.
3636 Xilinx MicroBlaze microblaze-*-*
3641 Xilinx MicroBlaze microblaze
3644 * Multi-program debugging.
3646 GDB now has support for multi-program (a.k.a. multi-executable or
3647 multi-exec) debugging. This allows for debugging multiple inferiors
3648 simultaneously each running a different program under the same GDB
3649 session. See "Debugging Multiple Inferiors and Programs" in the
3650 manual for more information. This implied some user visible changes
3651 in the multi-inferior support. For example, "info inferiors" now
3652 lists inferiors that are not running yet or that have exited
3653 already. See also "New commands" and "New options" below.
3655 * New tracing features
3657 GDB's tracepoint facility now includes several new features:
3659 ** Trace state variables
3661 GDB tracepoints now include support for trace state variables, which
3662 are variables managed by the target agent during a tracing
3663 experiment. They are useful for tracepoints that trigger each
3664 other, so for instance one tracepoint can count hits in a variable,
3665 and then a second tracepoint has a condition that is true when the
3666 count reaches a particular value. Trace state variables share the
3667 $-syntax of GDB convenience variables, and can appear in both
3668 tracepoint actions and condition expressions. Use the "tvariable"
3669 command to create, and "info tvariables" to view; see "Trace State
3670 Variables" in the manual for more detail.
3674 GDB now includes an option for defining fast tracepoints, which
3675 targets may implement more efficiently, such as by installing a jump
3676 into the target agent rather than a trap instruction. The resulting
3677 speedup can be by two orders of magnitude or more, although the
3678 tradeoff is that some program locations on some target architectures
3679 might not allow fast tracepoint installation, for instance if the
3680 instruction to be replaced is shorter than the jump. To request a
3681 fast tracepoint, use the "ftrace" command, with syntax identical to
3682 the regular trace command.
3684 ** Disconnected tracing
3686 It is now possible to detach GDB from the target while it is running
3687 a trace experiment, then reconnect later to see how the experiment
3688 is going. In addition, a new variable disconnected-tracing lets you
3689 tell the target agent whether to continue running a trace if the
3690 connection is lost unexpectedly.
3694 GDB now has the ability to save the trace buffer into a file, and
3695 then use that file as a target, similarly to you can do with
3696 corefiles. You can select trace frames, print data that was
3697 collected in them, and use tstatus to display the state of the
3698 tracing run at the moment that it was saved. To create a trace
3699 file, use "tsave <filename>", and to use it, do "target tfile
3702 ** Circular trace buffer
3704 You can ask the target agent to handle the trace buffer as a
3705 circular buffer, discarding the oldest trace frames to make room for
3706 newer ones, by setting circular-trace-buffer to on. This feature may
3707 not be available for all target agents.
3712 The disassemble command, when invoked with two arguments, now requires
3713 the arguments to be comma-separated.
3716 The info variables command now displays variable definitions. Files
3717 which only declare a variable are not shown.
3720 The source command is now capable of sourcing Python scripts.
3721 This feature is dependent on the debugger being build with Python
3724 Related to this enhancement is also the introduction of a new command
3725 "set script-extension" (see below).
3727 * New commands (for set/show, see "New options" below)
3729 record save [<FILENAME>]
3730 Save a file (in core file format) containing the process record
3731 execution log for replay debugging at a later time.
3733 record restore <FILENAME>
3734 Restore the process record execution log that was saved at an
3735 earlier time, for replay debugging.
3737 add-inferior [-copies <N>] [-exec <FILENAME>]
3740 clone-inferior [-copies <N>] [ID]
3741 Make a new inferior ready to execute the same program another
3742 inferior has loaded.
3747 maint info program-spaces
3748 List the program spaces loaded into GDB.
3750 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3751 show remote interrupt-sequence
3752 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3753 as the sequence to the remote target in order to interrupt the execution.
3754 Ctrl-C is a default. Some system prefers BREAK which is high level of
3755 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3756 Magic SysRq g. It is BREAK signal and character 'g'.
3758 set remote interrupt-on-connect [on | off]
3759 show remote interrupt-on-connect
3760 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3761 remote target when gdb connects to it. This is needed when you debug
3764 set remotebreak [on | off]
3766 Deprecated. Use "set/show remote interrupt-sequence" instead.
3768 tvariable $NAME [ = EXP ]
3769 Create or modify a trace state variable.
3772 List trace state variables and their values.
3774 delete tvariable $NAME ...
3775 Delete one or more trace state variables.
3778 Evaluate the given expressions without collecting anything into the
3779 trace buffer. (Valid in tracepoint actions only.)
3781 ftrace FN / FILE:LINE / *ADDR
3782 Define a fast tracepoint at the given function, line, or address.
3784 * New expression syntax
3786 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3787 GDB now parses 0b101010 identically with 42.
3791 set follow-exec-mode new|same
3792 show follow-exec-mode
3793 Control whether GDB reuses the same inferior across an exec call or
3794 creates a new one. This is useful to be able to restart the old
3795 executable after the inferior having done an exec call.
3797 set default-collect EXPR, ...
3798 show default-collect
3799 Define a list of expressions to be collected at each tracepoint.
3800 This is a useful way to ensure essential items are not overlooked,
3801 such as registers or a critical global variable.
3803 set disconnected-tracing
3804 show disconnected-tracing
3805 If set to 1, the target is instructed to continue tracing if it
3806 loses its connection to GDB. If 0, the target is to stop tracing
3809 set circular-trace-buffer
3810 show circular-trace-buffer
3811 If set to on, the target is instructed to use a circular trace buffer
3812 and discard the oldest trace frames instead of stopping the trace due
3813 to a full trace buffer. If set to off, the trace stops when the buffer
3814 fills up. Some targets may not support this.
3816 set script-extension off|soft|strict
3817 show script-extension
3818 If set to "off", the debugger does not perform any script language
3819 recognition, and all sourced files are assumed to be GDB scripts.
3820 If set to "soft" (the default), files are sourced according to
3821 filename extension, falling back to GDB scripts if the first
3823 If set to "strict", files are sourced according to filename extension.
3825 set ada trust-PAD-over-XVS on|off
3826 show ada trust-PAD-over-XVS
3827 If off, activate a workaround against a bug in the debugging information
3828 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3829 the GCC sources for more information about the GNAT encoding and
3830 PAD types in particular). It is always safe to set this option to
3831 off, but this introduces a slight performance penalty. The default
3834 * Python API Improvements
3836 ** GDB provides the new class gdb.LazyString. This is useful in
3837 some pretty-printing cases. The new method gdb.Value.lazy_string
3838 provides a simple way to create objects of this type.
3840 ** The fields returned by gdb.Type.fields now have an
3841 `is_base_class' attribute.
3843 ** The new method gdb.Type.range returns the range of an array type.
3845 ** The new method gdb.parse_and_eval can be used to parse and
3846 evaluate an expression.
3848 * New remote packets
3851 Define a trace state variable.
3854 Get the current value of a trace state variable.
3857 Set desired tracing behavior upon disconnection.
3860 Set the trace buffer to be linear or circular.
3863 Get data about the tracepoints currently in use.
3867 Process record now works correctly with hardware watchpoints.
3869 Multiple bug fixes have been made to the mips-irix port, making it
3870 much more reliable. In particular:
3871 - Debugging threaded applications is now possible again. Previously,
3872 GDB would hang while starting the program, or while waiting for
3873 the program to stop at a breakpoint.
3874 - Attaching to a running process no longer hangs.
3875 - An error occurring while loading a core file has been fixed.
3876 - Changing the value of the PC register now works again. This fixes
3877 problems observed when using the "jump" command, or when calling
3878 a function from GDB, or even when assigning a new value to $pc.
3879 - With the "finish" and "return" commands, the return value for functions
3880 returning a small array is now correctly printed.
3881 - It is now possible to break on shared library code which gets executed
3882 during a shared library init phase (code executed while executing
3883 their .init section). Previously, the breakpoint would have no effect.
3884 - GDB is now able to backtrace through the signal handler for
3885 non-threaded programs.
3887 PIE (Position Independent Executable) programs debugging is now supported.
3888 This includes debugging execution of PIC (Position Independent Code) shared
3889 libraries although for that, it should be possible to run such libraries as an
3892 *** Changes in GDB 7.0
3894 * GDB now has an interface for JIT compilation. Applications that
3895 dynamically generate code can create symbol files in memory and register
3896 them with GDB. For users, the feature should work transparently, and
3897 for JIT developers, the interface is documented in the GDB manual in the
3898 "JIT Compilation Interface" chapter.
3900 * Tracepoints may now be conditional. The syntax is as for
3901 breakpoints; either an "if" clause appended to the "trace" command,
3902 or the "condition" command is available. GDB sends the condition to
3903 the target for evaluation using the same bytecode format as is used
3904 for tracepoint actions.
3906 * The disassemble command now supports: an optional /r modifier, print the
3907 raw instructions in hex as well as in symbolic form, and an optional /m
3908 modifier to print mixed source+assembly.
3910 * Process record and replay
3912 In a architecture environment that supports ``process record and
3913 replay'', ``process record and replay'' target can record a log of
3914 the process execution, and replay it with both forward and reverse
3917 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3918 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3919 set execution-direction {forward|reverse}, for targets that support
3922 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3923 feature is available with a native GDB running on kernel version
3926 * GDB now has support for multi-byte and wide character sets on the
3927 target. Strings whose character type is wchar_t, char16_t, or
3928 char32_t are now correctly printed. GDB supports wide- and unicode-
3929 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3930 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3931 `printf'. This feature requires iconv to work properly; if your
3932 system does not have a working iconv, GDB can use GNU libiconv. See
3933 the installation instructions for more information.
3935 * GDB now supports automatic retrieval of shared library files from
3936 remote targets. To use this feature, specify a system root that begins
3937 with the `remote:' prefix, either via the `set sysroot' command or via
3938 the `--with-sysroot' configure-time option.
3940 * "info sharedlibrary" now takes an optional regex of libraries to show,
3941 and it now reports if a shared library has no debugging information.
3943 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3944 now complete on file names.
3946 * When completing in expressions, gdb will attempt to limit
3947 completions to allowable structure or union fields, where appropriate.
3948 For instance, consider:
3950 # struct example { int f1; double f2; };
3951 # struct example variable;
3954 If the user types TAB at the end of this command line, the available
3955 completions will be "f1" and "f2".
3957 * Inlined functions are now supported. They show up in backtraces, and
3958 the "step", "next", and "finish" commands handle them automatically.
3960 * GDB now supports the token-splicing (##) and stringification (#)
3961 operators when expanding macros. It also supports variable-arity
3964 * GDB now supports inspecting extra signal information, exported by
3965 the new $_siginfo convenience variable. The feature is currently
3966 implemented on linux ARM, i386 and amd64.
3968 * GDB can now display the VFP floating point registers and NEON vector
3969 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3970 can provide these registers (requires Linux 2.6.30 or later). Remote
3971 and simulator targets may also provide them.
3973 * New remote packets
3976 Search memory for a sequence of bytes.
3979 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3980 operation over reliable transport links. Use of this packet is
3981 controlled by the `set remote noack-packet' command.
3984 Kill the process with the specified process ID. Use this in preference
3985 to `k' when multiprocess protocol extensions are supported.
3988 Obtains additional operating system information
3992 Read or write additional signal information.
3994 * Removed remote protocol undocumented extension
3996 An undocumented extension to the remote protocol's `S' stop reply
3997 packet that permited the stub to pass a process id was removed.
3998 Remote servers should use the `T' stop reply packet instead.
4000 * GDB now supports multiple function calling conventions according to the
4001 DWARF-2 DW_AT_calling_convention function attribute.
4003 * The SH target utilizes the aforementioned change to distinguish between gcc
4004 and Renesas calling convention. It also adds the new CLI commands
4005 `set/show sh calling-convention'.
4007 * GDB can now read compressed debug sections, as produced by GNU gold
4008 with the --compress-debug-sections=zlib flag.
4010 * 64-bit core files are now supported on AIX.
4012 * Thread switching is now supported on Tru64.
4014 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4015 which will be allocated using malloc later in program execution.
4017 * The qXfer:libraries:read remote procotol packet now allows passing a
4018 list of section offsets.
4020 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4021 conditions handling signals delivered during attach or thread creation
4022 have also been fixed.
4024 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4025 From the user's standpoint, all unqualified instances of True and False
4026 are treated as the standard definitions, regardless of context.
4028 * GDB now parses C++ symbol and type names more flexibly. For
4031 template<typename T> class C { };
4034 GDB will now correctly handle all of:
4036 ptype C<char const *>
4037 ptype C<char const*>
4038 ptype C<const char *>
4039 ptype C<const char*>
4041 * New features in the GDB remote stub, gdbserver
4043 - The "--wrapper" command-line argument tells gdbserver to use a
4044 wrapper program to launch programs for debugging.
4046 - On PowerPC and S/390 targets, it is now possible to use a single
4047 gdbserver executable to debug both 32-bit and 64-bit programs.
4048 (This requires gdbserver itself to be built as a 64-bit executable.)
4050 - gdbserver uses the new noack protocol mode for TCP connections to
4051 reduce communications latency, if also supported and enabled in GDB.
4053 - Support for the sparc64-linux-gnu target is now included in
4056 - The amd64-linux build of gdbserver now supports debugging both
4057 32-bit and 64-bit programs.
4059 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4060 now support hardware watchpoints, and will use them automatically
4065 GDB now has support for scripting using Python. Whether this is
4066 available is determined at configure time.
4068 New GDB commands can now be written in Python.
4070 * Ada tasking support
4072 Ada tasks can now be inspected in GDB. The following commands have
4076 Print the list of Ada tasks.
4078 Print detailed information about task number N.
4080 Print the task number of the current task.
4082 Switch the context of debugging to task number N.
4084 * Support for user-defined prefixed commands. The "define" command can
4085 add new commands to existing prefixes, e.g. "target".
4087 * Multi-inferior, multi-process debugging.
4089 GDB now has generalized support for multi-inferior debugging. See
4090 "Debugging Multiple Inferiors" in the manual for more information.
4091 Although availability still depends on target support, the command
4092 set is more uniform now. The GNU/Linux specific multi-forks support
4093 has been migrated to this new framework. This implied some user
4094 visible changes; see "New commands" and also "Removed commands"
4097 * Target descriptions can now describe the target OS ABI. See the
4098 "Target Description Format" section in the user manual for more
4101 * Target descriptions can now describe "compatible" architectures
4102 to indicate that the target can execute applications for a different
4103 architecture in addition to those for the main target architecture.
4104 See the "Target Description Format" section in the user manual for
4107 * Multi-architecture debugging.
4109 GDB now includes general supports for debugging applications on
4110 hybrid systems that use more than one single processor architecture
4111 at the same time. Each such hybrid architecture still requires
4112 specific support to be added. The only hybrid architecture supported
4113 in this version of GDB is the Cell Broadband Engine.
4115 * GDB now supports integrated debugging of Cell/B.E. applications that
4116 use both the PPU and SPU architectures. To enable support for hybrid
4117 Cell/B.E. debugging, you need to configure GDB to support both the
4118 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4119 --enable-targets configure option.
4121 * Non-stop mode debugging.
4123 For some targets, GDB now supports an optional mode of operation in
4124 which you can examine stopped threads while other threads continue
4125 to execute freely. This is referred to as non-stop mode, with the
4126 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4127 section in the user manual for more information.
4129 To be able to support remote non-stop debugging, a remote stub needs
4130 to implement the non-stop mode remote protocol extensions, as
4131 described in the "Remote Non-Stop" section of the user manual. The
4132 GDB remote stub, gdbserver, has been adjusted to support these
4133 extensions on linux targets.
4135 * New commands (for set/show, see "New options" below)
4137 catch syscall [NAME(S) | NUMBER(S)]
4138 Catch system calls. Arguments, which should be names of system
4139 calls or their numbers, mean catch only those syscalls. Without
4140 arguments, every syscall will be caught. When the inferior issues
4141 any of the specified syscalls, GDB will stop and announce the system
4142 call, both when it is called and when its call returns. This
4143 feature is currently available with a native GDB running on the
4144 Linux Kernel, under the following architectures: x86, x86_64,
4145 PowerPC and PowerPC64.
4147 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4149 Search memory for a sequence of bytes.
4151 maint set python print-stack
4152 maint show python print-stack
4153 Show a stack trace when an error is encountered in a Python script.
4156 Invoke CODE by passing it to the Python interpreter.
4161 These allow macros to be defined, undefined, and listed
4165 Show operating system information about processes.
4168 List the inferiors currently under GDB's control.
4171 Switch focus to inferior number NUM.
4174 Detach from inferior number NUM.
4177 Kill inferior number NUM.
4181 set spu stop-on-load
4182 show spu stop-on-load
4183 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4185 set spu auto-flush-cache
4186 show spu auto-flush-cache
4187 Control whether to automatically flush the software-managed cache
4188 during Cell/B.E. debugging.
4190 set sh calling-convention
4191 show sh calling-convention
4192 Control the calling convention used when calling SH target functions.
4195 show debug timestamp
4196 Control display of timestamps with GDB debugging output.
4198 set disassemble-next-line
4199 show disassemble-next-line
4200 Control display of disassembled source lines or instructions when
4203 set remote noack-packet
4204 show remote noack-packet
4205 Set/show the use of remote protocol QStartNoAckMode packet. See above
4206 under "New remote packets."
4208 set remote query-attached-packet
4209 show remote query-attached-packet
4210 Control use of remote protocol `qAttached' (query-attached) packet.
4212 set remote read-siginfo-object
4213 show remote read-siginfo-object
4214 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4217 set remote write-siginfo-object
4218 show remote write-siginfo-object
4219 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4222 set remote reverse-continue
4223 show remote reverse-continue
4224 Control use of remote protocol 'bc' (reverse-continue) packet.
4226 set remote reverse-step
4227 show remote reverse-step
4228 Control use of remote protocol 'bs' (reverse-step) packet.
4230 set displaced-stepping
4231 show displaced-stepping
4232 Control displaced stepping mode. Displaced stepping is a way to
4233 single-step over breakpoints without removing them from the debuggee.
4234 Also known as "out-of-line single-stepping".
4237 show debug displaced
4238 Control display of debugging info for displaced stepping.
4240 maint set internal-error
4241 maint show internal-error
4242 Control what GDB does when an internal error is detected.
4244 maint set internal-warning
4245 maint show internal-warning
4246 Control what GDB does when an internal warning is detected.
4251 Use a wrapper program to launch programs for debugging.
4253 set multiple-symbols (all|ask|cancel)
4254 show multiple-symbols
4255 The value of this variable can be changed to adjust the debugger behavior
4256 when an expression or a breakpoint location contains an ambiguous symbol
4257 name (an overloaded function name, for instance).
4259 set breakpoint always-inserted
4260 show breakpoint always-inserted
4261 Keep breakpoints always inserted in the target, as opposed to inserting
4262 them when resuming the target, and removing them when the target stops.
4263 This option can improve debugger performance on slow remote targets.
4265 set arm fallback-mode (arm|thumb|auto)
4266 show arm fallback-mode
4267 set arm force-mode (arm|thumb|auto)
4269 These commands control how ARM GDB determines whether instructions
4270 are ARM or Thumb. The default for both settings is auto, which uses
4271 the current CPSR value for instructions without symbols; previous
4272 versions of GDB behaved as if "set arm fallback-mode arm".
4274 set disable-randomization
4275 show disable-randomization
4276 Standalone programs run with the virtual address space randomization enabled
4277 by default on some platforms. This option keeps the addresses stable across
4278 multiple debugging sessions.
4282 Control whether other threads are stopped or not when some thread hits
4287 Requests that asynchronous execution is enabled in the target, if available.
4288 In this case, it's possible to resume target in the background, and interact
4289 with GDB while the target is running. "show target-async" displays the
4290 current state of asynchronous execution of the target.
4292 set target-wide-charset
4293 show target-wide-charset
4294 The target-wide-charset is the name of the character set that GDB
4295 uses when printing characters whose type is wchar_t.
4297 set tcp auto-retry (on|off)
4299 set tcp connect-timeout
4300 show tcp connect-timeout
4301 These commands allow GDB to retry failed TCP connections to a remote stub
4302 with a specified timeout period; this is useful if the stub is launched
4303 in parallel with GDB but may not be ready to accept connections immediately.
4305 set libthread-db-search-path
4306 show libthread-db-search-path
4307 Control list of directories which GDB will search for appropriate
4310 set schedule-multiple (on|off)
4311 show schedule-multiple
4312 Allow GDB to resume all threads of all processes or only threads of
4313 the current process.
4317 Use more aggressive caching for accesses to the stack. This improves
4318 performance of remote debugging (particularly backtraces) without
4319 affecting correctness.
4321 set interactive-mode (on|off|auto)
4322 show interactive-mode
4323 Control whether GDB runs in interactive mode (on) or not (off).
4324 When in interactive mode, GDB waits for the user to answer all
4325 queries. Otherwise, GDB does not wait and assumes the default
4326 answer. When set to auto (the default), GDB determines which
4327 mode to use based on the stdin settings.
4332 For program forks, this is replaced by the new more generic `info
4333 inferiors' command. To list checkpoints, you can still use the
4334 `info checkpoints' command, which was an alias for the `info forks'
4338 Replaced by the new `inferior' command. To switch between
4339 checkpoints, you can still use the `restart' command, which was an
4340 alias for the `fork' command.
4343 This is removed, since some targets don't have a notion of
4344 processes. To switch between processes, you can still use the
4345 `inferior' command using GDB's own inferior number.
4348 For program forks, this is replaced by the new more generic `kill
4349 inferior' command. To delete a checkpoint, you can still use the
4350 `delete checkpoint' command, which was an alias for the `delete
4354 For program forks, this is replaced by the new more generic `detach
4355 inferior' command. To detach a checkpoint, you can still use the
4356 `detach checkpoint' command, which was an alias for the `detach
4359 * New native configurations
4361 x86/x86_64 Darwin i[34567]86-*-darwin*
4363 x86_64 MinGW x86_64-*-mingw*
4367 Lattice Mico32 lm32-*
4368 x86 DICOS i[34567]86-*-dicos*
4369 x86_64 DICOS x86_64-*-dicos*
4372 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4373 (mingw32ce) debugging.
4379 These commands were actually not implemented on any target.
4381 *** Changes in GDB 6.8
4383 * New native configurations
4385 NetBSD/hppa hppa*-*netbsd*
4386 Xtensa GNU/Linux xtensa*-*-linux*
4390 NetBSD/hppa hppa*-*-netbsd*
4391 Xtensa GNU/Lunux xtensa*-*-linux*
4393 * Change in command line behavior -- corefiles vs. process ids.
4395 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4396 attaching to process NUMBER fails, GDB no longer attempts to open a
4397 core file named NUMBER. Attaching to a program using the -c option
4398 is no longer supported. Instead, use the '-p' or '--pid' options.
4400 * GDB can now be built as a native debugger for debugging Windows x86
4401 (mingw32) Portable Executable (PE) programs.
4403 * Pending breakpoints no longer change their number when their address
4406 * GDB now supports breakpoints with multiple locations,
4407 including breakpoints on C++ constructors, inside C++ templates,
4408 and in inlined functions.
4410 * GDB's ability to debug optimized code has been improved. GDB more
4411 accurately identifies function bodies and lexical blocks that occupy
4412 more than one contiguous range of addresses.
4414 * Target descriptions can now describe registers for PowerPC.
4416 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4417 registers on PowerPC targets.
4419 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4420 targets even when the libthread_db library is not available.
4422 * The GDB remote stub, gdbserver, now supports the new file transfer
4423 commands (remote put, remote get, and remote delete).
4425 * The GDB remote stub, gdbserver, now supports run and attach in
4426 extended-remote mode.
4428 * hppa*64*-*-hpux11* target broken
4429 The debugger is unable to start a program and fails with the following
4430 error: "Error trying to get information about dynamic linker".
4431 The gdb-6.7 release is also affected.
4433 * GDB now supports the --enable-targets= configure option to allow
4434 building a single GDB executable that supports multiple remote
4435 target architectures.
4437 * GDB now supports debugging C and C++ programs which use the
4438 Decimal Floating Point extension. In addition, the PowerPC target
4439 now has a set of pseudo-registers to inspect decimal float values
4440 stored in two consecutive float registers.
4442 * The -break-insert MI command can optionally create pending
4445 * Improved support for debugging Ada
4446 Many improvements to the Ada language support have been made. These
4448 - Better support for Ada2005 interface types
4449 - Improved handling of arrays and slices in general
4450 - Better support for Taft-amendment types
4451 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4453 - Improved command completion in Ada
4456 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4461 set print frame-arguments (all|scalars|none)
4462 show print frame-arguments
4463 The value of this variable can be changed to control which argument
4464 values should be printed by the debugger when displaying a frame.
4469 Transfer files to and from a remote target, and delete remote files.
4476 Transfer files to and from a remote target, and delete remote files.
4478 * New remote packets
4485 Open, close, read, write, and delete files on the remote system.
4488 Attach to an existing process on the remote system, in extended-remote
4492 Run a new process on the remote system, in extended-remote mode.
4494 *** Changes in GDB 6.7
4496 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4497 bfd, libiberty and opcodes, as revealed by static analysis donated by
4498 Coverity, Inc. (http://scan.coverity.com).
4500 * When looking up multiply-defined global symbols, GDB will now prefer the
4501 symbol definition in the current shared library if it was built using the
4502 -Bsymbolic linker option.
4504 * When the Text User Interface (TUI) is not configured, GDB will now
4505 recognize the -tui command-line option and print a message that the TUI
4508 * The GDB remote stub, gdbserver, now has lower overhead for high
4509 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4511 * GDB for MIPS targets now autodetects whether a remote target provides
4512 32-bit or 64-bit register values.
4514 * Support for C++ member pointers has been improved.
4516 * GDB now understands XML target descriptions, which specify the
4517 target's overall architecture. GDB can read a description from
4518 a local file or over the remote serial protocol.
4520 * Vectors of single-byte data use a new integer type which is not
4521 automatically displayed as character or string data.
4523 * The /s format now works with the print command. It displays
4524 arrays of single-byte integers and pointers to single-byte integers
4527 * Target descriptions can now describe target-specific registers,
4528 for architectures which have implemented the support (currently
4529 only ARM, M68K, and MIPS).
4531 * GDB and the GDB remote stub, gdbserver, now support the XScale
4534 * The GDB remote stub, gdbserver, has been updated to support
4535 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4536 has been rewritten to use the standard GDB remote protocol.
4538 * GDB can now step into C++ functions which are called through thunks.
4540 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4542 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4543 layout. It also supports a TextSeg= and DataSeg= response when only
4544 segment base addresses (rather than offsets) are available.
4546 * The /i format now outputs any trailing branch delay slot instructions
4547 immediately following the last instruction within the count specified.
4549 * The GDB remote protocol "T" stop reply packet now supports a
4550 "library" response. Combined with the new "qXfer:libraries:read"
4551 packet, this response allows GDB to debug shared libraries on targets
4552 where the operating system manages the list of loaded libraries (e.g.
4553 Windows and SymbianOS).
4555 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4556 (DLLs) on Windows and Windows CE targets.
4558 * GDB now supports a faster verification that a .debug file matches its binary
4559 according to its build-id signature, if the signature is present.
4565 Enable or disable hardware flow control (RTS/CTS) on the serial port
4566 when debugging using remote targets.
4568 set mem inaccessible-by-default
4569 show mem inaccessible-by-default
4570 If the target supplies a memory map, for instance via the remote
4571 protocol's "qXfer:memory-map:read" packet, setting this variable
4572 prevents GDB from accessing memory outside the memory map. This
4573 is useful for targets with memory mapped registers or which react
4574 badly to accesses of unmapped address space.
4576 set breakpoint auto-hw
4577 show breakpoint auto-hw
4578 If the target supplies a memory map, for instance via the remote
4579 protocol's "qXfer:memory-map:read" packet, setting this variable
4580 lets GDB use hardware breakpoints automatically for memory regions
4581 where it can not use software breakpoints. This covers both the
4582 "break" command and internal breakpoints used for other commands
4583 including "next" and "finish".
4586 catch exception unhandled
4587 Stop the program execution when Ada exceptions are raised.
4590 Stop the program execution when an Ada assertion failed.
4594 Set an alternate system root for target files. This is a more
4595 general version of "set solib-absolute-prefix", which is now
4596 an alias to "set sysroot".
4599 Provide extended SPU facility status information. This set of
4600 commands is available only when debugging the Cell/B.E. SPU
4603 * New native configurations
4605 OpenBSD/sh sh*-*openbsd*
4608 unset tdesc filename
4610 Use the specified local file as an XML target description, and do
4611 not query the target for its built-in description.
4615 OpenBSD/sh sh*-*-openbsd*
4616 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4617 Toshiba Media Processor mep-elf
4619 * New remote packets
4622 Ignore the specified signals; pass them directly to the debugged program
4623 without stopping other threads or reporting them to GDB.
4625 qXfer:features:read:
4626 Read an XML target description from the target, which describes its
4631 Read or write contents of an spufs file on the target system. These
4632 packets are available only on the Cell/B.E. SPU architecture.
4634 qXfer:libraries:read:
4635 Report the loaded shared libraries. Combined with new "T" packet
4636 response, this packet allows GDB to debug shared libraries on
4637 targets where the operating system manages the list of loaded
4638 libraries (e.g. Windows and SymbianOS).
4642 Support for these obsolete configurations has been removed.
4650 i[34567]86-*-lynxos*
4651 i[34567]86-*-netware*
4652 i[34567]86-*-sco3.2v5*
4653 i[34567]86-*-sco3.2v4*
4655 i[34567]86-*-sysv4.2*
4658 i[34567]86-*-unixware2*
4659 i[34567]86-*-unixware*
4668 * Other removed features
4675 Various m68k-only ROM monitors.
4682 Various Renesas ROM monitors and debugging interfaces for SH and
4687 Support for a Macraigor serial interface to on-chip debugging.
4688 GDB does not directly support the newer parallel or USB
4693 A debug information format. The predecessor to DWARF 2 and
4694 DWARF 3, which are still supported.
4696 Support for the HP aCC compiler on HP-UX/PA-RISC
4698 SOM-encapsulated symbolic debugging information, automatic
4699 invocation of pxdb, and the aCC custom C++ ABI. This does not
4700 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4701 with aCC can still be debugged on an assembly level.
4703 MIPS ".pdr" sections
4705 A MIPS-specific format used to describe stack frame layout
4706 in debugging information.
4710 GDB could work with an older version of Guile to debug
4711 the interpreter and Scheme programs running in it.
4713 set mips stack-arg-size
4714 set mips saved-gpreg-size
4716 Use "set mips abi" to control parameter passing for MIPS.
4718 *** Changes in GDB 6.6
4723 Cell Broadband Engine SPU spu-elf
4725 * GDB can now be configured as a cross-debugger targeting native Windows
4726 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4727 running on a Windows system over TCP/IP to debug Windows programs.
4729 * The GDB remote stub, gdbserver, has been updated to support Windows and
4730 Cygwin debugging. Both single-threaded and multi-threaded programs are
4733 * The "set trust-readonly-sections" command works again. This command was
4734 broken in GDB 6.3, 6.4, and 6.5.
4736 * The "load" command now supports writing to flash memory, if the remote
4737 stub provides the required support.
4739 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4740 longer requires symbolic debug information (e.g. DWARF-2).
4745 unset substitute-path
4746 show substitute-path
4747 Manage a list of substitution rules that GDB uses to rewrite the name
4748 of the directories where the sources are located. This can be useful
4749 for instance when the sources were moved to a different location
4750 between compilation and debugging.
4754 Print each CLI command as it is executed. Each command is prefixed with
4755 a number of `+' symbols representing the nesting depth.
4756 The source command now has a `-v' option to enable the same feature.
4760 The ARM Demon monitor support (RDP protocol, "target rdp").
4762 Kernel Object Display, an embedded debugging feature which only worked with
4763 an obsolete version of Cisco IOS.
4765 The 'set download-write-size' and 'show download-write-size' commands.
4767 * New remote packets
4770 Tell a stub about GDB client features, and request remote target features.
4771 The first feature implemented is PacketSize, which allows the target to
4772 specify the size of packets it can handle - to minimize the number of
4773 packets required and improve performance when connected to a remote
4777 Fetch an OS auxilliary vector from the remote stub. This packet is a
4778 more efficient replacement for qPart:auxv:read.
4780 qXfer:memory-map:read:
4781 Fetch a memory map from the remote stub, including information about
4782 RAM, ROM, and flash memory devices.
4787 Erase and program a flash memory device.
4789 * Removed remote packets
4792 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4793 used it, and only gdbserver implemented it.
4795 *** Changes in GDB 6.5
4799 Renesas M32C/M16C m32c-elf
4801 Morpho Technologies ms1 ms1-elf
4805 init-if-undefined Initialize a convenience variable, but
4806 only if it doesn't already have a value.
4808 The following commands are presently only implemented for native GNU/Linux:
4810 checkpoint Save a snapshot of the program state.
4812 restart <n> Return the program state to a
4813 previously saved state.
4815 info checkpoints List currently saved checkpoints.
4817 delete-checkpoint <n> Delete a previously saved checkpoint.
4819 set|show detach-on-fork Tell gdb whether to detach from a newly
4820 forked process, or to keep debugging it.
4822 info forks List forks of the user program that
4823 are available to be debugged.
4825 fork <n> Switch to debugging one of several
4826 forks of the user program that are
4827 available to be debugged.
4829 delete-fork <n> Delete a fork from the list of forks
4830 that are available to be debugged (and
4831 kill the forked process).
4833 detach-fork <n> Delete a fork from the list of forks
4834 that are available to be debugged (and
4835 allow the process to continue).
4839 Morpho Technologies ms2 ms1-elf
4841 * Improved Windows host support
4843 GDB now builds as a cross debugger hosted on i686-mingw32, including
4844 native console support, and remote communications using either
4845 network sockets or serial ports.
4847 * Improved Modula-2 language support
4849 GDB can now print most types in the Modula-2 syntax. This includes:
4850 basic types, set types, record types, enumerated types, range types,
4851 pointer types and ARRAY types. Procedure var parameters are correctly
4852 printed and hexadecimal addresses and character constants are also
4853 written in the Modula-2 syntax. Best results can be obtained by using
4854 GNU Modula-2 together with the -gdwarf-2 command line option.
4858 The ARM rdi-share module.
4860 The Netware NLM debug server.
4862 *** Changes in GDB 6.4
4864 * New native configurations
4866 OpenBSD/arm arm*-*-openbsd*
4867 OpenBSD/mips64 mips64-*-openbsd*
4871 Morpho Technologies ms1 ms1-elf
4873 * New command line options
4875 --batch-silent As for --batch, but totally silent.
4876 --return-child-result The debugger will exist with the same value
4877 the child (debugged) program exited with.
4878 --eval-command COMMAND, -ex COMMAND
4879 Execute a single GDB CLI command. This may be
4880 specified multiple times and in conjunction
4881 with the --command (-x) option.
4883 * Deprecated commands removed
4885 The following commands, that were deprecated in 2000, have been
4889 set|show arm disassembly-flavor set|show arm disassembler
4890 othernames set arm disassembler
4891 set|show remotedebug set|show debug remote
4892 set|show archdebug set|show debug arch
4893 set|show eventdebug set|show debug event
4896 * New BSD user-level threads support
4898 It is now possible to debug programs using the user-level threads
4899 library on OpenBSD and FreeBSD. Currently supported (target)
4902 FreeBSD/amd64 x86_64-*-freebsd*
4903 FreeBSD/i386 i386-*-freebsd*
4904 OpenBSD/i386 i386-*-openbsd*
4906 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4907 are not yet supported.
4909 * New support for Matsushita MN10300 w/sim added
4910 (Work in progress). mn10300-elf.
4912 * REMOVED configurations and files
4914 VxWorks and the XDR protocol *-*-vxworks
4915 Motorola MCORE mcore-*-*
4916 National Semiconductor NS32000 ns32k-*-*
4918 * New "set print array-indexes" command
4920 After turning this setting "on", GDB prints the index of each element
4921 when displaying arrays. The default is "off" to preserve the previous
4924 * VAX floating point support
4926 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4928 * User-defined command support
4930 In addition to using $arg0..$arg9 for argument passing, it is now possible
4931 to use $argc to determine now many arguments have been passed. See the
4932 section on user-defined commands in the user manual for more information.
4934 *** Changes in GDB 6.3:
4936 * New command line option
4938 GDB now accepts -l followed by a number to set the timeout for remote
4941 * GDB works with GCC -feliminate-dwarf2-dups
4943 GDB now supports a more compact representation of DWARF-2 debug
4944 information using DW_FORM_ref_addr references. These are produced
4945 by GCC with the option -feliminate-dwarf2-dups and also by some
4946 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4947 to use -feliminate-dwarf2-dups.
4949 * Internationalization
4951 When supported by the host system, GDB will be built with
4952 internationalization (libintl). The task of marking up the sources is
4953 continued, we're looking forward to our first translation.
4957 Initial support for debugging programs compiled with the GNAT
4958 implementation of the Ada programming language has been integrated
4959 into GDB. In this release, support is limited to expression evaluation.
4961 * New native configurations
4963 GNU/Linux/m32r m32r-*-linux-gnu
4967 GDB's remote protocol now includes support for the 'p' packet. This
4968 packet is used to fetch individual registers from a remote inferior.
4970 * END-OF-LIFE registers[] compatibility module
4972 GDB's internal register infrastructure has been completely rewritten.
4973 The new infrastructure making possible the implementation of key new
4974 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4977 GDB 6.3 will be the last release to include the the registers[]
4978 compatibility module that allowed out-of-date configurations to
4979 continue to work. This change directly impacts the following
4989 powerpc bdm protocol
4991 Unless there is activity to revive these configurations, they will be
4992 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4994 * OBSOLETE configurations and files
4996 Configurations that have been declared obsolete in this release have
4997 been commented out. Unless there is activity to revive these
4998 configurations, the next release of GDB will have their sources
4999 permanently REMOVED.
5008 *** Changes in GDB 6.2.1:
5010 * MIPS `break main; run' gave an heuristic-fence-post warning
5012 When attempting to run even a simple program, a warning about
5013 heuristic-fence-post being hit would be reported. This problem has
5016 * MIPS IRIX 'long double' crashed GDB
5018 When examining a long double variable, GDB would get a segmentation
5019 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5020 IRIX long double values).
5024 A bug in the VAX stack code was causing problems with the "next"
5025 command. This problem has been fixed.
5027 *** Changes in GDB 6.2:
5029 * Fix for ``many threads''
5031 On GNU/Linux systems that use the NPTL threads library, a program
5032 rapidly creating and deleting threads would confuse GDB leading to the
5035 ptrace: No such process.
5036 thread_db_get_info: cannot get thread info: generic error
5038 This problem has been fixed.
5040 * "-async" and "-noasync" options removed.
5042 Support for the broken "-noasync" option has been removed (it caused
5045 * New ``start'' command.
5047 This command runs the program until the begining of the main procedure.
5049 * New BSD Kernel Data Access Library (libkvm) interface
5051 Using ``target kvm'' it is now possible to debug kernel core dumps and
5052 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5053 platforms. Currently supported (native-only) configurations are:
5055 FreeBSD/amd64 x86_64-*-freebsd*
5056 FreeBSD/i386 i?86-*-freebsd*
5057 NetBSD/i386 i?86-*-netbsd*
5058 NetBSD/m68k m68*-*-netbsd*
5059 NetBSD/sparc sparc-*-netbsd*
5060 OpenBSD/amd64 x86_64-*-openbsd*
5061 OpenBSD/i386 i?86-*-openbsd*
5062 OpenBSD/m68k m68*-openbsd*
5063 OpenBSD/sparc sparc-*-openbsd*
5065 * Signal trampoline code overhauled
5067 Many generic problems with GDB's signal handling code have been fixed.
5068 These include: backtraces through non-contiguous stacks; recognition
5069 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5070 call; backtrace through a signal trampoline; step into and out of
5071 signal handlers; and single-stepping in the signal trampoline.
5073 Please note that kernel bugs are a limiting factor here. These
5074 features have been shown to work on an s390 GNU/Linux system that
5075 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5077 * Cygwin support for DWARF 2 added.
5079 * New native configurations
5081 GNU/Linux/hppa hppa*-*-linux*
5082 OpenBSD/hppa hppa*-*-openbsd*
5083 OpenBSD/m68k m68*-*-openbsd*
5084 OpenBSD/m88k m88*-*-openbsd*
5085 OpenBSD/powerpc powerpc-*-openbsd*
5086 NetBSD/vax vax-*-netbsd*
5087 OpenBSD/vax vax-*-openbsd*
5089 * END-OF-LIFE frame compatibility module
5091 GDB's internal frame infrastructure has been completely rewritten.
5092 The new infrastructure making it possible to support key new features
5093 including DWARF 2 Call Frame Information. To aid in the task of
5094 migrating old configurations to this new infrastructure, a
5095 compatibility module, that allowed old configurations to continue to
5096 work, was also included.
5098 GDB 6.2 will be the last release to include this frame compatibility
5099 module. This change directly impacts the following configurations:
5109 Unless there is activity to revive these configurations, they will be
5110 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5112 * REMOVED configurations and files
5114 Sun 3, running SunOS 3 m68*-*-sunos3*
5115 Sun 3, running SunOS 4 m68*-*-sunos4*
5116 Sun 2, running SunOS 3 m68000-*-sunos3*
5117 Sun 2, running SunOS 4 m68000-*-sunos4*
5118 Motorola 680x0 running LynxOS m68*-*-lynxos*
5119 AT&T 3b1/Unix pc m68*-att-*
5120 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5121 decstation mips-dec-* mips-little-*
5122 riscos mips-*-riscos* mips-*-sysv*
5123 sonymips mips-sony-*
5124 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5126 *** Changes in GDB 6.1.1:
5128 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5130 The TUI (Text-mode User Interface) is now built as part of a default
5131 GDB configuration. It is enabled by either selecting the TUI with the
5132 command line option "-i=tui" or by running the separate "gdbtui"
5133 program. For more information on the TUI, see the manual "Debugging
5136 * Pending breakpoint support (also included in GDB 6.1)
5138 Support has been added to allow you to specify breakpoints in shared
5139 libraries that have not yet been loaded. If a breakpoint location
5140 cannot be found, and the "breakpoint pending" option is set to auto,
5141 GDB queries you if you wish to make the breakpoint pending on a future
5142 shared-library load. If and when GDB resolves the breakpoint symbol,
5143 the pending breakpoint is removed as one or more regular breakpoints
5146 Pending breakpoints are very useful for GCJ Java debugging.
5148 * Fixed ISO-C build problems
5150 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5151 non ISO-C code that stopped them being built using a more strict ISO-C
5152 compiler (e.g., IBM's C compiler).
5154 * Fixed build problem on IRIX 5
5156 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5157 wasn't able to compile compile on an IRIX 5 system.
5159 * Added execute permission to gdb/gdbserver/configure
5161 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5162 permission. This bug would cause configure to fail on a number of
5163 systems (Solaris, IRIX). Ref: server/519.
5165 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5167 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5168 has been updated to use constant array sizes.
5170 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5172 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5173 its generated DWARF Call Frame Info. This encoding was causing GDB to
5174 panic, that panic has been fixed. Ref: gdb/1628.
5176 * Fixed a problem when examining parameters in shared library code.
5178 When examining parameters in optimized shared library code generated
5179 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5180 not available''. GDB now correctly displays the variable's value.
5182 *** Changes in GDB 6.1:
5184 * Removed --with-mmalloc
5186 Support for the mmalloc memory manager has been removed, as it
5187 conflicted with the internal gdb byte cache.
5189 * Changes in AMD64 configurations
5191 The AMD64 target now includes the %cs and %ss registers. As a result
5192 the AMD64 remote protocol has changed; this affects the floating-point
5193 and SSE registers. If you rely on those registers for your debugging,
5194 you should upgrade gdbserver on the remote side.
5196 * Revised SPARC target
5198 The SPARC target has been completely revised, incorporating the
5199 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5200 support for LynxOS and SunOS 4 has been dropped. Calling functions
5201 from within GDB on operating systems with a non-executable stack
5202 (Solaris, OpenBSD) now works.
5206 GDB has a new C++ demangler which does a better job on the mangled
5207 names generated by current versions of g++. It also runs faster, so
5208 with this and other changes gdb should now start faster on large C++
5211 * DWARF 2 Location Expressions
5213 GDB support for location expressions has been extended to support function
5214 arguments and frame bases. Older versions of GDB could crash when they
5217 * C++ nested types and namespaces
5219 GDB's support for nested types and namespaces in C++ has been
5220 improved, especially if you use the DWARF 2 debugging format. (This
5221 is the default for recent versions of GCC on most platforms.)
5222 Specifically, if you have a class "Inner" defined within a class or
5223 namespace "Outer", then GDB realizes that the class's name is
5224 "Outer::Inner", not simply "Inner". This should greatly reduce the
5225 frequency of complaints about not finding RTTI symbols. In addition,
5226 if you are stopped at inside of a function defined within a namespace,
5227 GDB modifies its name lookup accordingly.
5229 * New native configurations
5231 NetBSD/amd64 x86_64-*-netbsd*
5232 OpenBSD/amd64 x86_64-*-openbsd*
5233 OpenBSD/alpha alpha*-*-openbsd*
5234 OpenBSD/sparc sparc-*-openbsd*
5235 OpenBSD/sparc64 sparc64-*-openbsd*
5237 * New debugging protocols
5239 M32R with SDI protocol m32r-*-elf*
5241 * "set prompt-escape-char" command deleted.
5243 The command "set prompt-escape-char" has been deleted. This command,
5244 and its very obscure effet on GDB's prompt, was never documented,
5245 tested, nor mentioned in the NEWS file.
5247 * OBSOLETE configurations and files
5249 Configurations that have been declared obsolete in this release have
5250 been commented out. Unless there is activity to revive these
5251 configurations, the next release of GDB will have their sources
5252 permanently REMOVED.
5254 Sun 3, running SunOS 3 m68*-*-sunos3*
5255 Sun 3, running SunOS 4 m68*-*-sunos4*
5256 Sun 2, running SunOS 3 m68000-*-sunos3*
5257 Sun 2, running SunOS 4 m68000-*-sunos4*
5258 Motorola 680x0 running LynxOS m68*-*-lynxos*
5259 AT&T 3b1/Unix pc m68*-att-*
5260 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5261 decstation mips-dec-* mips-little-*
5262 riscos mips-*-riscos* mips-*-sysv*
5263 sonymips mips-sony-*
5264 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5266 * REMOVED configurations and files
5268 SGI Irix-4.x mips-sgi-irix4 or iris4
5269 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5270 Z8000 simulator z8k-zilog-none or z8ksim
5271 Matsushita MN10200 w/simulator mn10200-*-*
5272 H8/500 simulator h8500-hitachi-hms or h8500hms
5273 HP/PA running BSD hppa*-*-bsd*
5274 HP/PA running OSF/1 hppa*-*-osf*
5275 HP/PA Pro target hppa*-*-pro*
5276 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5277 386BSD i[3456]86-*-bsd*
5278 Sequent family i[3456]86-sequent-sysv4*
5279 i[3456]86-sequent-sysv*
5280 i[3456]86-sequent-bsd*
5281 SPARC running LynxOS sparc-*-lynxos*
5282 SPARC running SunOS 4 sparc-*-sunos4*
5283 Tsqware Sparclet sparclet-*-*
5284 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5286 *** Changes in GDB 6.0:
5290 Support for debugging the Objective-C programming language has been
5291 integrated into GDB.
5293 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5295 DWARF 2's Call Frame Information makes available compiler generated
5296 information that more exactly describes the program's run-time stack.
5297 By using this information, GDB is able to provide more robust stack
5300 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5301 have been updated to use a new backtrace mechanism which includes
5302 DWARF 2 CFI support.
5306 GDB's remote protocol has been extended to include support for hosted
5307 file I/O (where the remote target uses GDB's file system). See GDB's
5308 remote protocol documentation for details.
5310 * All targets using the new architecture framework.
5312 All of GDB's targets have been updated to use the new internal
5313 architecture framework. The way is now open for future GDB releases
5314 to include cross-architecture native debugging support (i386 on amd64,
5317 * GNU/Linux's Thread Local Storage (TLS)
5319 GDB now includes support for for the GNU/Linux implementation of
5320 per-thread variables.
5322 * GNU/Linux's Native POSIX Thread Library (NPTL)
5324 GDB's thread code has been updated to work with either the new
5325 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5327 * Separate debug info.
5329 GDB, in conjunction with BINUTILS, now supports a mechanism for
5330 automatically loading debug information from a separate file. Instead
5331 of shipping full debug and non-debug versions of system libraries,
5332 system integrators can now instead ship just the stripped libraries
5333 and optional debug files.
5335 * DWARF 2 Location Expressions
5337 DWARF 2 Location Expressions allow the compiler to more completely
5338 describe the location of variables (even in optimized code) to the
5341 GDB now includes preliminary support for location expressions (support
5342 for DW_OP_piece is still missing).
5346 A number of long standing bugs that caused GDB to die while starting a
5347 Java application have been fixed. GDB's Java support is now
5348 considered "useable".
5350 * GNU/Linux support for fork, vfork, and exec.
5352 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5353 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5356 * GDB supports logging output to a file
5358 There are two new commands, "set logging" and "show logging", which can be
5359 used to capture GDB's output to a file.
5361 * The meaning of "detach" has changed for gdbserver
5363 The "detach" command will now resume the application, as documented. To
5364 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5367 * d10v, m68hc11 `regs' command deprecated
5369 The `info registers' command has been updated so that it displays the
5370 registers using a format identical to the old `regs' command.
5374 A new command, "maint set profile on/off", has been added. This command can
5375 be used to enable or disable profiling while running GDB, to profile a
5376 session or a set of commands. In addition there is a new configure switch,
5377 "--enable-profiling", which will cause GDB to be compiled with profiling
5378 data, for more informative profiling results.
5380 * Default MI syntax changed to "mi2".
5382 The default MI (machine interface) syntax, enabled by the command line
5383 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5384 "mi1", can be enabled by specifying the option "-i=mi1".
5386 Support for the original "mi0" syntax (included in GDB 5.0) has been
5389 Fix for gdb/192: removed extraneous space when displaying frame level.
5390 Fix for gdb/672: update changelist is now output in mi list format.
5391 Fix for gdb/702: a -var-assign that updates the value now shows up
5392 in a subsequent -var-update.
5394 * New native configurations.
5396 FreeBSD/amd64 x86_64-*-freebsd*
5398 * Multi-arched targets.
5400 HP/PA HPUX11 hppa*-*-hpux*
5401 Renesas M32R/D w/simulator m32r-*-elf*
5403 * OBSOLETE configurations and files
5405 Configurations that have been declared obsolete in this release have
5406 been commented out. Unless there is activity to revive these
5407 configurations, the next release of GDB will have their sources
5408 permanently REMOVED.
5410 Z8000 simulator z8k-zilog-none or z8ksim
5411 Matsushita MN10200 w/simulator mn10200-*-*
5412 H8/500 simulator h8500-hitachi-hms or h8500hms
5413 HP/PA running BSD hppa*-*-bsd*
5414 HP/PA running OSF/1 hppa*-*-osf*
5415 HP/PA Pro target hppa*-*-pro*
5416 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5417 Sequent family i[3456]86-sequent-sysv4*
5418 i[3456]86-sequent-sysv*
5419 i[3456]86-sequent-bsd*
5420 Tsqware Sparclet sparclet-*-*
5421 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5423 * REMOVED configurations and files
5426 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5427 IBM AIX PS/2 i[3456]86-*-aix
5428 i386 running Mach 3.0 i[3456]86-*-mach3*
5429 i386 running Mach i[3456]86-*-mach*
5430 i386 running OSF/1 i[3456]86-*osf1mk*
5431 HP/Apollo 68k Family m68*-apollo*-sysv*,
5433 m68*-hp-bsd*, m68*-hp-hpux*
5434 Argonaut Risc Chip (ARC) arc-*-*
5435 Mitsubishi D30V d30v-*-*
5436 Fujitsu FR30 fr30-*-elf*
5437 OS/9000 i[34]86-*-os9k
5438 I960 with MON960 i960-*-coff
5440 * MIPS $fp behavior changed
5442 The convenience variable $fp, for the MIPS, now consistently returns
5443 the address of the current frame's base. Previously, depending on the
5444 context, $fp could refer to either $sp or the current frame's base
5445 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5446 The GNU Source-Level Debugger''.
5448 *** Changes in GDB 5.3:
5450 * GNU/Linux shared library multi-threaded performance improved.
5452 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5453 `/proc', in preference to `ptrace' for memory reads. This may result
5454 in an improvement in the start-up time of multi-threaded, shared
5455 library applications when run under GDB. One GDB user writes: ``loads
5456 shared libs like mad''.
5458 * ``gdbserver'' now supports multi-threaded applications on some targets
5460 Support for debugging multi-threaded applications which use
5461 the GNU/Linux LinuxThreads package has been added for
5462 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5463 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5465 * GDB now supports C/C++ preprocessor macros.
5467 GDB now expands preprocessor macro invocations in C/C++ expressions,
5468 and provides various commands for showing macro definitions and how
5471 The new command `macro expand EXPRESSION' expands any macro
5472 invocations in expression, and shows the result.
5474 The new command `show macro MACRO-NAME' shows the definition of the
5475 macro named MACRO-NAME, and where it was defined.
5477 Most compilers don't include information about macros in the debugging
5478 information by default. In GCC 3.1, for example, you need to compile
5479 your program with the options `-gdwarf-2 -g3'. If the macro
5480 information is present in the executable, GDB will read it.
5482 * Multi-arched targets.
5484 DEC Alpha (partial) alpha*-*-*
5485 DEC VAX (partial) vax-*-*
5487 National Semiconductor NS32000 (partial) ns32k-*-*
5488 Motorola 68000 (partial) m68k-*-*
5489 Motorola MCORE mcore-*-*
5493 Fujitsu FRV architecture added by Red Hat frv*-*-*
5496 * New native configurations
5498 Alpha NetBSD alpha*-*-netbsd*
5499 SH NetBSD sh*-*-netbsdelf*
5500 MIPS NetBSD mips*-*-netbsd*
5501 UltraSPARC NetBSD sparc64-*-netbsd*
5503 * OBSOLETE configurations and files
5505 Configurations that have been declared obsolete in this release have
5506 been commented out. Unless there is activity to revive these
5507 configurations, the next release of GDB will have their sources
5508 permanently REMOVED.
5510 Mitsubishi D30V d30v-*-*
5511 OS/9000 i[34]86-*-os9k
5512 IBM AIX PS/2 i[3456]86-*-aix
5513 Fujitsu FR30 fr30-*-elf*
5514 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5515 Argonaut Risc Chip (ARC) arc-*-*
5516 i386 running Mach 3.0 i[3456]86-*-mach3*
5517 i386 running Mach i[3456]86-*-mach*
5518 i386 running OSF/1 i[3456]86-*osf1mk*
5519 HP/Apollo 68k Family m68*-apollo*-sysv*,
5521 m68*-hp-bsd*, m68*-hp-hpux*
5522 I960 with MON960 i960-*-coff
5524 * OBSOLETE languages
5526 CHILL, a Pascal like language used by telecommunications companies.
5528 * REMOVED configurations and files
5530 AMD 29k family via UDI a29k-amd-udi, udi29k
5531 A29K VxWorks a29k-*-vxworks
5532 AMD 29000 embedded, using EBMON a29k-none-none
5533 AMD 29000 embedded with COFF a29k-none-coff
5534 AMD 29000 embedded with a.out a29k-none-aout
5536 testsuite/gdb.hp/gdb.threads-hp/ directory
5538 * New command "set max-user-call-depth <nnn>"
5540 This command allows the user to limit the call depth of user-defined
5541 commands. The default is 1024.
5543 * Changes in FreeBSD/i386 native debugging.
5545 Support for the "generate-core-file" has been added.
5547 * New commands "dump", "append", and "restore".
5549 These commands allow data to be copied from target memory
5550 to a bfd-format or binary file (dump and append), and back
5551 from a file into memory (restore).
5553 * Improved "next/step" support on multi-processor Alpha Tru64.
5555 The previous single-step mechanism could cause unpredictable problems,
5556 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5557 of a software single-step mechanism prevents this.
5559 *** Changes in GDB 5.2.1:
5567 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5568 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5569 Fix, by Joel Brobecker imported from mainline.
5571 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5572 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5573 Fix, by Fred Fish, imported from mainline.
5575 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5576 Surprisingly enough, it works now.
5577 By Michal Ludvig, imported from mainline.
5579 i386 hardware watchpoint support:
5580 avoid misses on second run for some targets.
5581 By Pierre Muller, imported from mainline.
5583 *** Changes in GDB 5.2:
5585 * New command "set trust-readonly-sections on[off]".
5587 This command is a hint that tells gdb that read-only sections
5588 really are read-only (ie. that their contents will not change).
5589 In this mode, gdb will go to the object file rather than the
5590 target to read memory from read-only sections (such as ".text").
5591 This can be a significant performance improvement on some
5592 (notably embedded) targets.
5594 * New command "generate-core-file" (or "gcore").
5596 This new gdb command allows the user to drop a core file of the child
5597 process state at any time. So far it's been implemented only for
5598 GNU/Linux and Solaris, but should be relatively easily ported to other
5599 hosts. Argument is core file name (defaults to core.<pid>).
5601 * New command line option
5603 GDB now accepts --pid or -p followed by a process id.
5605 * Change in command line behavior -- corefiles vs. process ids.
5607 There is a subtle behavior in the way in which GDB handles
5608 command line arguments. The first non-flag argument is always
5609 a program to debug, but the second non-flag argument may either
5610 be a corefile or a process id. Previously, GDB would attempt to
5611 open the second argument as a corefile, and if that failed, would
5612 issue a superfluous error message and then attempt to attach it as
5613 a process. Now, if the second argument begins with a non-digit,
5614 it will be treated as a corefile. If it begins with a digit,
5615 GDB will attempt to attach it as a process, and if no such process
5616 is found, will then attempt to open it as a corefile.
5618 * Changes in ARM configurations.
5620 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5621 configuration is fully multi-arch.
5623 * New native configurations
5625 ARM NetBSD arm*-*-netbsd*
5626 x86 OpenBSD i[3456]86-*-openbsd*
5627 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5628 Sparc64 running FreeBSD sparc64-*-freebsd*
5632 Sanyo XStormy16 xstormy16-elf
5634 * OBSOLETE configurations and files
5636 Configurations that have been declared obsolete in this release have
5637 been commented out. Unless there is activity to revive these
5638 configurations, the next release of GDB will have their sources
5639 permanently REMOVED.
5641 AMD 29k family via UDI a29k-amd-udi, udi29k
5642 A29K VxWorks a29k-*-vxworks
5643 AMD 29000 embedded, using EBMON a29k-none-none
5644 AMD 29000 embedded with COFF a29k-none-coff
5645 AMD 29000 embedded with a.out a29k-none-aout
5647 testsuite/gdb.hp/gdb.threads-hp/ directory
5649 * REMOVED configurations and files
5651 TI TMS320C80 tic80-*-*
5653 PowerPC Solaris powerpcle-*-solaris*
5654 PowerPC Windows NT powerpcle-*-cygwin32
5655 PowerPC Netware powerpc-*-netware*
5656 Harris/CXUX m88k m88*-harris-cxux*
5657 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5658 ns32k-utek-sysv* ns32k-utek-*
5659 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5660 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5661 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5662 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5663 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5665 * Changes to command line processing
5667 The new `--args' feature can be used to specify command-line arguments
5668 for the inferior from gdb's command line.
5670 * Changes to key bindings
5672 There is a new `operate-and-get-next' function bound to `C-o'.
5674 *** Changes in GDB 5.1.1
5676 Fix compile problem on DJGPP.
5678 Fix a problem with floating-point registers on the i386 being
5681 Fix to stop GDB crashing on .debug_str debug info.
5683 Numerous documentation fixes.
5685 Numerous testsuite fixes.
5687 *** Changes in GDB 5.1:
5689 * New native configurations
5691 Alpha FreeBSD alpha*-*-freebsd*
5692 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5693 MIPS GNU/Linux mips*-*-linux*
5694 MIPS SGI Irix 6.x mips*-sgi-irix6*
5695 ia64 AIX ia64-*-aix*
5696 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5700 Motorola 68HC11 and 68HC12 m68hc11-elf
5702 UltraSparc running GNU/Linux sparc64-*-linux*
5704 * OBSOLETE configurations and files
5706 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5707 Harris/CXUX m88k m88*-harris-cxux*
5708 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5709 ns32k-utek-sysv* ns32k-utek-*
5710 TI TMS320C80 tic80-*-*
5712 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5713 PowerPC Solaris powerpcle-*-solaris*
5714 PowerPC Windows NT powerpcle-*-cygwin32
5715 PowerPC Netware powerpc-*-netware*
5716 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5717 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5718 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5719 Apple Macintosh (MPW) host N/A
5721 stuff.c (Program to stuff files into a specially prepared space in kdb)
5722 kdb-start.c (Main loop for the standalone kernel debugger)
5724 Configurations that have been declared obsolete in this release have
5725 been commented out. Unless there is activity to revive these
5726 configurations, the next release of GDB will have their sources
5727 permanently REMOVED.
5729 * REMOVED configurations and files
5731 Altos 3068 m68*-altos-*
5732 Convex c1-*-*, c2-*-*
5734 ARM RISCix arm-*-* (as host)
5738 * GDB has been converted to ISO C.
5740 GDB's source code has been converted to ISO C. In particular, the
5741 sources are fully protoized, and rely on standard headers being
5746 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5748 * The MI enabled by default.
5750 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5751 revised and enabled by default. Packages which use GDB as a debugging
5752 engine behind a UI or another front end are encouraged to switch to
5753 using the GDB/MI interface, instead of the old annotations interface
5754 which is now deprecated.
5756 * Support for debugging Pascal programs.
5758 GDB now includes support for debugging Pascal programs. The following
5759 main features are supported:
5761 - Pascal-specific data types such as sets;
5763 - automatic recognition of Pascal sources based on file-name
5766 - Pascal-style display of data types, variables, and functions;
5768 - a Pascal expression parser.
5770 However, some important features are not yet supported.
5772 - Pascal string operations are not supported at all;
5774 - there are some problems with boolean types;
5776 - Pascal type hexadecimal constants are not supported
5777 because they conflict with the internal variables format;
5779 - support for Pascal objects and classes is not full yet;
5781 - unlike Pascal, GDB is case-sensitive for symbol names.
5783 * Changes in completion.
5785 Commands such as `shell', `run' and `set args', which pass arguments
5786 to inferior programs, now complete on file names, similar to what
5787 users expect at the shell prompt.
5789 Commands which accept locations, such as `disassemble', `print',
5790 `breakpoint', `until', etc. now complete on filenames as well as
5791 program symbols. Thus, if you type "break foob TAB", and the source
5792 files linked into the programs include `foobar.c', that file name will
5793 be one of the candidates for completion. However, file names are not
5794 considered for completion after you typed a colon that delimits a file
5795 name from a name of a function in that file, as in "break foo.c:bar".
5797 `set demangle-style' completes on available demangling styles.
5799 * New platform-independent commands:
5801 It is now possible to define a post-hook for a command as well as a
5802 hook that runs before the command. For more details, see the
5803 documentation of `hookpost' in the GDB manual.
5805 * Changes in GNU/Linux native debugging.
5807 Support for debugging multi-threaded programs has been completely
5808 revised for all platforms except m68k and sparc. You can now debug as
5809 many threads as your system allows you to have.
5811 Attach/detach is supported for multi-threaded programs.
5813 Support for SSE registers was added for x86. This doesn't work for
5814 multi-threaded programs though.
5816 * Changes in MIPS configurations.
5818 Multi-arch support is enabled for all MIPS configurations.
5820 GDB can now be built as native debugger on SGI Irix 6.x systems for
5821 debugging n32 executables. (Debugging 64-bit executables is not yet
5824 * Unified support for hardware watchpoints in all x86 configurations.
5826 Most (if not all) native x86 configurations support hardware-assisted
5827 breakpoints and watchpoints in a unified manner. This support
5828 implements debug register sharing between watchpoints, which allows to
5829 put a virtually infinite number of watchpoints on the same address,
5830 and also supports watching regions up to 16 bytes with several debug
5833 The new maintenance command `maintenance show-debug-regs' toggles
5834 debugging print-outs in functions that insert, remove, and test
5835 watchpoints and hardware breakpoints.
5837 * Changes in the DJGPP native configuration.
5839 New command ``info dos sysinfo'' displays assorted information about
5840 the CPU, OS, memory, and DPMI server.
5842 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5843 display information about segment descriptors stored in GDT, LDT, and
5846 New commands ``info dos pde'' and ``info dos pte'' display entries
5847 from Page Directory and Page Tables (for now works with CWSDPMI only).
5848 New command ``info dos address-pte'' displays the Page Table entry for
5849 a given linear address.
5851 GDB can now pass command lines longer than 126 characters to the
5852 program being debugged (requires an update to the libdbg.a library
5853 which is part of the DJGPP development kit).
5855 DWARF2 debug info is now supported.
5857 It is now possible to `step' and `next' through calls to `longjmp'.
5859 * Changes in documentation.
5861 All GDB documentation was converted to GFDL, the GNU Free
5862 Documentation License.
5864 Tracepoints-related commands are now fully documented in the GDB
5867 TUI, the Text-mode User Interface, is now documented in the manual.
5869 Tracepoints-related commands are now fully documented in the GDB
5872 The "GDB Internals" manual now has an index. It also includes
5873 documentation of `ui_out' functions, GDB coding standards, x86
5874 hardware watchpoints, and memory region attributes.
5876 * GDB's version number moved to ``version.in''
5878 The Makefile variable VERSION has been replaced by the file
5879 ``version.in''. People creating GDB distributions should update the
5880 contents of this file.
5884 GUD support is now a standard part of the EMACS distribution.
5886 *** Changes in GDB 5.0:
5888 * Improved support for debugging FP programs on x86 targets
5890 Unified and much-improved support for debugging floating-point
5891 programs on all x86 targets. In particular, ``info float'' now
5892 displays the FP registers in the same format on all x86 targets, with
5893 greater level of detail.
5895 * Improvements and bugfixes in hardware-assisted watchpoints
5897 It is now possible to watch array elements, struct members, and
5898 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5899 on x86 targets no longer erroneously trigger when the address is
5902 * Improvements in the native DJGPP version of GDB
5904 The distribution now includes all the scripts and auxiliary files
5905 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5906 machines ``out of the box''.
5908 The DJGPP version can now debug programs that use signals. It is
5909 possible to catch signals that happened in the debuggee, deliver
5910 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5911 would kill the program being debugged.) Programs that hook hardware
5912 interrupts (keyboard, timer, etc.) can also be debugged.
5914 It is now possible to debug DJGPP programs that redirect their
5915 standard handles or switch them to raw (as opposed to cooked) mode, or
5916 even close them. The command ``run < foo > bar'' works as expected,
5917 and ``info terminal'' reports useful information about the debuggee's
5918 terminal, including raw/cooked mode, redirection, etc.
5920 The DJGPP version now uses termios functions for console I/O, which
5921 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5924 DOS-style file names with drive letters are now fully supported by
5927 It is now possible to debug DJGPP programs that switch their working
5928 directory. It is also possible to rerun the debuggee any number of
5929 times without restarting GDB; thus, you can use the same setup,
5930 breakpoints, etc. for many debugging sessions.
5932 * New native configurations
5934 ARM GNU/Linux arm*-*-linux*
5935 PowerPC GNU/Linux powerpc-*-linux*
5939 Motorola MCore mcore-*-*
5940 x86 VxWorks i[3456]86-*-vxworks*
5941 PowerPC VxWorks powerpc-*-vxworks*
5942 TI TMS320C80 tic80-*-*
5944 * OBSOLETE configurations
5946 Altos 3068 m68*-altos-*
5947 Convex c1-*-*, c2-*-*
5949 ARM RISCix arm-*-* (as host)
5952 Configurations that have been declared obsolete will be commented out,
5953 but the code will be left in place. If there is no activity to revive
5954 these configurations before the next release of GDB, the sources will
5955 be permanently REMOVED.
5957 * Gould support removed
5959 Support for the Gould PowerNode and NP1 has been removed.
5961 * New features for SVR4
5963 On SVR4 native platforms (such as Solaris), if you attach to a process
5964 without first loading a symbol file, GDB will now attempt to locate and
5965 load symbols from the running process's executable file.
5967 * Many C++ enhancements
5969 C++ support has been greatly improved. Overload resolution now works properly
5970 in almost all cases. RTTI support is on the way.
5972 * Remote targets can connect to a sub-program
5974 A popen(3) style serial-device has been added. This device starts a
5975 sub-process (such as a stand-alone simulator) and then communicates
5976 with that. The sub-program to run is specified using the syntax
5977 ``|<program> <args>'' vis:
5979 (gdb) set remotedebug 1
5980 (gdb) target extended-remote |mn10300-elf-sim program-args
5982 * MIPS 64 remote protocol
5984 A long standing bug in the mips64 remote protocol where by GDB
5985 expected certain 32 bit registers (ex SR) to be transfered as 32
5986 instead of 64 bits has been fixed.
5988 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5989 added to provide backward compatibility with older versions of GDB.
5991 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5993 The command ``set remotebinarydownload'' command has been replaced by
5994 ``set remote X-packet''. Other commands in ``set remote'' family
5995 include ``set remote P-packet''.
5997 * Breakpoint commands accept ranges.
5999 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6000 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6001 ``tracepoint passcount'' also accepts a range of tracepoints.
6003 * ``apropos'' command added.
6005 The ``apropos'' command searches through command names and
6006 documentation strings, printing out matches, making it much easier to
6007 try to find a command that does what you are looking for.
6011 A new machine oriented interface (MI) has been added to GDB. This
6012 interface is designed for debug environments running GDB as a separate
6013 process. This is part of the long term libGDB project. See the
6014 "GDB/MI" chapter of the GDB manual for further information. It can be
6015 enabled by configuring with:
6017 .../configure --enable-gdbmi
6019 *** Changes in GDB-4.18:
6021 * New native configurations
6023 HP-UX 10.20 hppa*-*-hpux10.20
6024 HP-UX 11.x hppa*-*-hpux11.0*
6025 M68K GNU/Linux m68*-*-linux*
6029 Fujitsu FR30 fr30-*-elf*
6030 Intel StrongARM strongarm-*-*
6031 Mitsubishi D30V d30v-*-*
6033 * OBSOLETE configurations
6035 Gould PowerNode, NP1 np1-*-*, pn-*-*
6037 Configurations that have been declared obsolete will be commented out,
6038 but the code will be left in place. If there is no activity to revive
6039 these configurations before the next release of GDB, the sources will
6040 be permanently REMOVED.
6044 As a compatibility experiment, GDB's source files buildsym.h and
6045 buildsym.c have been converted to pure standard C, no longer
6046 containing any K&R compatibility code. We believe that all systems in
6047 use today either come with a standard C compiler, or have a GCC port
6048 available. If this is not true, please report the affected
6049 configuration to bug-gdb@gnu.org immediately. See the README file for
6050 information about getting a standard C compiler if you don't have one
6055 GDB now uses readline 2.2.
6057 * set extension-language
6059 You can now control the mapping between filename extensions and source
6060 languages by using the `set extension-language' command. For instance,
6061 you can ask GDB to treat .c files as C++ by saying
6062 set extension-language .c c++
6063 The command `info extensions' lists all of the recognized extensions
6064 and their associated languages.
6066 * Setting processor type for PowerPC and RS/6000
6068 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6069 you can use the `set processor' command to specify what variant of the
6070 PowerPC family you are debugging. The command
6074 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6075 following PowerPC and RS6000 variants:
6077 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6078 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6080 403GC IBM PowerPC 403GC
6081 505 Motorola PowerPC 505
6082 860 Motorola PowerPC 860 or 850
6083 601 Motorola PowerPC 601
6084 602 Motorola PowerPC 602
6085 603 Motorola/IBM PowerPC 603 or 603e
6086 604 Motorola PowerPC 604 or 604e
6087 750 Motorola/IBM PowerPC 750 or 750
6089 At the moment, this command just tells GDB what to name the
6090 special-purpose processor registers. Since almost all the affected
6091 registers are inaccessible to user-level programs, this command is
6092 only useful for remote debugging in its present form.
6096 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6097 more extensive support for HP-UX. Added features include shared
6098 library support, kernel threads and hardware watchpoints for 11.00,
6099 support for HP's ANSI C and C++ compilers, and a compatibility mode
6100 for xdb and dbx commands.
6104 HP's donation includes the new concept of catchpoints, which is a
6105 generalization of the old catch command. On HP-UX, it is now possible
6106 to catch exec, fork, and vfork, as well as library loading.
6108 This means that the existing catch command has changed; its first
6109 argument now specifies the type of catch to be set up. See the
6110 output of "help catch" for a list of catchpoint types.
6112 * Debugging across forks
6114 On HP-UX, you can choose which process to debug when a fork() happens
6119 HP has donated a curses-based terminal user interface (TUI). To get
6120 it, build with --enable-tui. Although this can be enabled for any
6121 configuration, at present it only works for native HP debugging.
6123 * GDB remote protocol additions
6125 A new protocol packet 'X' that writes binary data is now available.
6126 Default behavior is to try 'X', then drop back to 'M' if the stub
6127 fails to respond. The settable variable `remotebinarydownload'
6128 allows explicit control over the use of 'X'.
6130 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6131 full 64-bit address. The command
6133 set remoteaddresssize 32
6135 can be used to revert to the old behaviour. For existing remote stubs
6136 the change should not be noticed, as the additional address information
6139 In order to assist in debugging stubs, you may use the maintenance
6140 command `packet' to send any text string to the stub. For instance,
6142 maint packet heythere
6144 sends the packet "$heythere#<checksum>". Note that it is very easy to
6145 disrupt a debugging session by sending the wrong packet at the wrong
6148 The compare-sections command allows you to compare section data on the
6149 target to what is in the executable file without uploading or
6150 downloading, by comparing CRC checksums.
6152 * Tracing can collect general expressions
6154 You may now collect general expressions at tracepoints. This requires
6155 further additions to the target-side stub; see tracepoint.c and
6156 doc/agentexpr.texi for further details.
6158 * mask-address variable for Mips
6160 For Mips targets, you may control the zeroing of the upper 32 bits of
6161 a 64-bit address by entering `set mask-address on'. This is mainly
6162 of interest to users of embedded R4xxx and R5xxx processors.
6164 * Higher serial baud rates
6166 GDB's serial code now allows you to specify baud rates 57600, 115200,
6167 230400, and 460800 baud. (Note that your host system may not be able
6168 to achieve all of these rates.)
6172 The i960 configuration now includes an initial implementation of a
6173 builtin simulator, contributed by Jim Wilson.
6176 *** Changes in GDB-4.17:
6178 * New native configurations
6180 Alpha GNU/Linux alpha*-*-linux*
6181 Unixware 2.x i[3456]86-unixware2*
6182 Irix 6.x mips*-sgi-irix6*
6183 PowerPC GNU/Linux powerpc-*-linux*
6184 PowerPC Solaris powerpcle-*-solaris*
6185 Sparc GNU/Linux sparc-*-linux*
6186 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6190 Argonaut Risc Chip (ARC) arc-*-*
6191 Hitachi H8/300S h8300*-*-*
6192 Matsushita MN10200 w/simulator mn10200-*-*
6193 Matsushita MN10300 w/simulator mn10300-*-*
6194 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6195 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6196 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6197 Mitsubishi D10V w/simulator d10v-*-*
6198 Mitsubishi M32R/D w/simulator m32r-*-elf*
6199 Tsqware Sparclet sparclet-*-*
6200 NEC V850 w/simulator v850-*-*
6202 * New debugging protocols
6204 ARM with RDI protocol arm*-*-*
6205 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6206 DDB and LSI variants of PMON protocol mips*-*-*
6207 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6208 PowerPC with SDS protocol powerpc{,le}-*-eabi
6209 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6213 All configurations can now understand and use the DWARF 2 debugging
6214 format. The choice is automatic, if the symbol file contains DWARF 2
6219 GDB now includes basic Java language support. This support is
6220 only useful with Java compilers that produce native machine code.
6222 * solib-absolute-prefix and solib-search-path
6224 For SunOS and SVR4 shared libraries, you may now set the prefix for
6225 loading absolute shared library symbol files, and the search path for
6226 locating non-absolute shared library symbol files.
6228 * Live range splitting
6230 GDB can now effectively debug code for which GCC has performed live
6231 range splitting as part of its optimization. See gdb/doc/LRS for
6232 more details on the expected format of the stabs information.
6236 GDB's support for the GNU Hurd, including thread debugging, has been
6237 updated to work with current versions of the Hurd.
6241 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6242 instruction set. ARM GDB automatically detects when Thumb
6243 instructions are in use, and adjusts disassembly and backtracing
6248 GDB's MIPS target configurations now handle the MIP16 16-bit
6253 GDB now includes support for overlays; if an executable has been
6254 linked such that multiple sections are based at the same address, GDB
6255 will decide which section to use for symbolic info. You can choose to
6256 control the decision manually, using overlay commands, or implement
6257 additional target-side support and use "overlay load-target" to bring
6258 in the overlay mapping. Do "help overlay" for more detail.
6262 The command "info symbol <address>" displays information about
6263 the symbol at the specified address.
6267 The standard remote protocol now includes an extension that allows
6268 asynchronous collection and display of trace data. This requires
6269 extensive support in the target-side debugging stub. Tracing mode
6270 includes a new interaction mode in GDB and new commands: see the
6271 file tracepoint.c for more details.
6275 Configurations for embedded MIPS now include a simulator contributed
6276 by Cygnus Solutions. The simulator supports the instruction sets
6277 of most MIPS variants.
6281 Sparc configurations may now include the ERC32 simulator contributed
6282 by the European Space Agency. The simulator is not built into
6283 Sparc targets by default; configure with --enable-sim to include it.
6287 For target configurations that may include multiple variants of a
6288 basic architecture (such as MIPS and SH), you may now set the
6289 architecture explicitly. "set arch" sets, "info arch" lists
6290 the possible architectures.
6292 *** Changes in GDB-4.16:
6294 * New native configurations
6296 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6297 M68K NetBSD m68k-*-netbsd*
6298 PowerPC AIX 4.x powerpc-*-aix*
6299 PowerPC MacOS powerpc-*-macos*
6300 PowerPC Windows NT powerpcle-*-cygwin32
6301 RS/6000 AIX 4.x rs6000-*-aix4*
6305 ARM with RDP protocol arm-*-*
6306 I960 with MON960 i960-*-coff
6307 MIPS VxWorks mips*-*-vxworks*
6308 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6309 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6311 Matra Sparclet sparclet-*-*
6315 The powerpc-eabi configuration now includes the PSIM simulator,
6316 contributed by Andrew Cagney, with assistance from Mike Meissner.
6317 PSIM is a very elaborate model of the PowerPC, including not only
6318 basic instruction set execution, but also details of execution unit
6319 performance and I/O hardware. See sim/ppc/README for more details.
6323 GDB now works with Solaris 2.5.
6325 * Windows 95/NT native
6327 GDB will now work as a native debugger on Windows 95 and Windows NT.
6328 To build it from source, you must use the "gnu-win32" environment,
6329 which uses a DLL to emulate enough of Unix to run the GNU tools.
6330 Further information, binaries, and sources are available at
6331 ftp.cygnus.com, under pub/gnu-win32.
6333 * dont-repeat command
6335 If a user-defined command includes the command `dont-repeat', then the
6336 command will not be repeated if the user just types return. This is
6337 useful if the command is time-consuming to run, so that accidental
6338 extra keystrokes don't run the same command many times.
6340 * Send break instead of ^C
6342 The standard remote protocol now includes an option to send a break
6343 rather than a ^C to the target in order to interrupt it. By default,
6344 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6346 * Remote protocol timeout
6348 The standard remote protocol includes a new variable `remotetimeout'
6349 that allows you to set the number of seconds before GDB gives up trying
6350 to read from the target. The default value is 2.
6352 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6354 By default GDB will automatically keep track of objects as they are
6355 loaded and unloaded by the dynamic linker. By using the command `set
6356 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6357 when shared library events occur, thus allowing you to set breakpoints
6358 in shared libraries which are explicitly loaded by the inferior.
6360 Note this feature does not work on hpux8. On hpux9 you must link
6361 /usr/lib/end.o into your program. This feature should work
6362 automatically on hpux10.
6364 * Irix 5.x hardware watchpoint support
6366 Irix 5 configurations now support the use of hardware watchpoints.
6368 * Mips protocol "SYN garbage limit"
6370 When debugging a Mips target using the `target mips' protocol, you
6371 may set the number of characters that GDB will ignore by setting
6372 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6373 every character. The default value is 1050.
6375 * Recording and replaying remote debug sessions
6377 If you set `remotelogfile' to the name of a file, gdb will write to it
6378 a recording of a remote debug session. This recording may then be
6379 replayed back to gdb using "gdbreplay". See gdbserver/README for
6380 details. This is useful when you have a problem with GDB while doing
6381 remote debugging; you can make a recording of the session and send it
6382 to someone else, who can then recreate the problem.
6384 * Speedups for remote debugging
6386 GDB includes speedups for downloading and stepping MIPS systems using
6387 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6388 and more efficient S-record downloading.
6390 * Memory use reductions and statistics collection
6392 GDB now uses less memory and reports statistics about memory usage.
6393 Try the `maint print statistics' command, for example.
6395 *** Changes in GDB-4.15:
6397 * Psymtabs for XCOFF
6399 The symbol reader for AIX GDB now uses partial symbol tables. This
6400 can greatly improve startup time, especially for large executables.
6402 * Remote targets use caching
6404 Remote targets now use a data cache to speed up communication with the
6405 remote side. The data cache could lead to incorrect results because
6406 it doesn't know about volatile variables, thus making it impossible to
6407 debug targets which use memory mapped I/O devices. `set remotecache
6408 off' turns the the data cache off.
6410 * Remote targets may have threads
6412 The standard remote protocol now includes support for multiple threads
6413 in the target system, using new protocol commands 'H' and 'T'. See
6414 gdb/remote.c for details.
6418 If GDB is configured with `--enable-netrom', then it will include
6419 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6420 acts as though it is a bank of ROM on the target board, but you can
6421 write into it over the network. GDB's support consists only of
6422 support for fast loading into the emulated ROM; to debug, you must use
6423 another protocol, such as standard remote protocol. The usual
6424 sequence is something like
6426 target nrom <netrom-hostname>
6428 target remote <netrom-hostname>:1235
6432 GDB now includes support for the Apple Macintosh, as a host only. It
6433 may be run as either an MPW tool or as a standalone application, and
6434 it can debug through the serial port. All the usual GDB commands are
6435 available, but to the target command, you must supply "serial" as the
6436 device type instead of "/dev/ttyXX". See mpw-README in the main
6437 directory for more information on how to build. The MPW configuration
6438 scripts */mpw-config.in support only a few targets, and only the
6439 mips-idt-ecoff target has been tested.
6443 GDB configuration now uses autoconf. This is not user-visible,
6444 but does simplify configuration and building.
6448 GDB now supports hpux10.
6450 *** Changes in GDB-4.14:
6452 * New native configurations
6454 x86 FreeBSD i[345]86-*-freebsd
6455 x86 NetBSD i[345]86-*-netbsd
6456 NS32k NetBSD ns32k-*-netbsd
6457 Sparc NetBSD sparc-*-netbsd
6461 A29K VxWorks a29k-*-vxworks
6462 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6463 CPU32 EST-300 emulator m68*-*-est*
6464 PowerPC ELF powerpc-*-elf
6467 * Alpha OSF/1 support for procfs
6469 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6470 possible to attach to running processes. As the mounting of the /proc
6471 filesystem is optional on the Alpha, GDB automatically determines
6472 the availability of /proc during startup. This can lead to problems
6473 if /proc is unmounted after GDB has been started.
6475 * Arguments to user-defined commands
6477 User commands may accept up to 10 arguments separated by whitespace.
6478 Arguments are accessed within the user command via $arg0..$arg9. A
6481 print $arg0 + $arg1 + $arg2
6483 To execute the command use:
6486 Defines the command "adder" which prints the sum of its three arguments.
6487 Note the arguments are text substitutions, so they may reference variables,
6488 use complex expressions, or even perform inferior function calls.
6490 * New `if' and `while' commands
6492 This makes it possible to write more sophisticated user-defined
6493 commands. Both commands take a single argument, which is the
6494 expression to evaluate, and must be followed by the commands to
6495 execute, one per line, if the expression is nonzero, the list being
6496 terminated by the word `end'. The `if' command list may include an
6497 `else' word, which causes the following commands to be executed only
6498 if the expression is zero.
6500 * Fortran source language mode
6502 GDB now includes partial support for Fortran 77. It will recognize
6503 Fortran programs and can evaluate a subset of Fortran expressions, but
6504 variables and functions may not be handled correctly. GDB will work
6505 with G77, but does not yet know much about symbols emitted by other
6508 * Better HPUX support
6510 Most debugging facilities now work on dynamic executables for HPPAs
6511 running hpux9 or later. You can attach to running dynamically linked
6512 processes, but by default the dynamic libraries will be read-only, so
6513 for instance you won't be able to put breakpoints in them. To change
6514 that behavior do the following before running the program:
6520 This will cause the libraries to be mapped private and read-write.
6521 To revert to the normal behavior, do this:
6527 You cannot set breakpoints or examine data in the library until after
6528 the library is loaded if the function/data symbols do not have
6531 GDB can now also read debug symbols produced by the HP C compiler on
6532 HPPAs (sorry, no C++, Fortran or 68k support).
6534 * Target byte order now dynamically selectable
6536 You can choose which byte order to use with a target system, via the
6537 commands "set endian big" and "set endian little", and you can see the
6538 current setting by using "show endian". You can also give the command
6539 "set endian auto", in which case GDB will use the byte order
6540 associated with the executable. Currently, only embedded MIPS
6541 configurations support dynamic selection of target byte order.
6543 * New DOS host serial code
6545 This version uses DPMI interrupts to handle buffered I/O, so you
6546 no longer need to run asynctsr when debugging boards connected to
6549 *** Changes in GDB-4.13:
6551 * New "complete" command
6553 This lists all the possible completions for the rest of the line, if it
6554 were to be given as a command itself. This is intended for use by emacs.
6556 * Trailing space optional in prompt
6558 "set prompt" no longer adds a space for you after the prompt you set. This
6559 allows you to set a prompt which ends in a space or one that does not.
6561 * Breakpoint hit counts
6563 "info break" now displays a count of the number of times the breakpoint
6564 has been hit. This is especially useful in conjunction with "ignore"; you
6565 can ignore a large number of breakpoint hits, look at the breakpoint info
6566 to see how many times the breakpoint was hit, then run again, ignoring one
6567 less than that number, and this will get you quickly to the last hit of
6570 * Ability to stop printing at NULL character
6572 "set print null-stop" will cause GDB to stop printing the characters of
6573 an array when the first NULL is encountered. This is useful when large
6574 arrays actually contain only short strings.
6576 * Shared library breakpoints
6578 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6579 breakpoints in shared libraries before the executable is run.
6581 * Hardware watchpoints
6583 There is a new hardware breakpoint for the watch command for sparclite
6584 targets. See gdb/sparclite/hw_breakpoint.note.
6586 Hardware watchpoints are also now supported under GNU/Linux.
6590 Annotations have been added. These are for use with graphical interfaces,
6591 and are still experimental. Currently only gdba.el uses these.
6593 * Improved Irix 5 support
6595 GDB now works properly with Irix 5.2.
6597 * Improved HPPA support
6599 GDB now works properly with the latest GCC and GAS.
6601 * New native configurations
6603 Sequent PTX4 i[34]86-sequent-ptx4
6604 HPPA running OSF/1 hppa*-*-osf*
6605 Atari TT running SVR4 m68*-*-sysv4*
6606 RS/6000 LynxOS rs6000-*-lynxos*
6610 OS/9000 i[34]86-*-os9k
6611 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6614 * Hitachi SH7000 and E7000-PC ICE support
6616 There is now support for communicating with the Hitachi E7000-PC ICE.
6617 This is available automatically when GDB is configured for the SH.
6621 As usual, a variety of small fixes and improvements, both generic
6622 and configuration-specific. See the ChangeLog for more detail.
6624 *** Changes in GDB-4.12:
6626 * Irix 5 is now supported
6630 GDB-4.12 on the HPPA has a number of changes which make it unable
6631 to debug the output from the currently released versions of GCC and
6632 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6633 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6634 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6637 *** Changes in GDB-4.11:
6639 * User visible changes:
6643 The "set remotedebug" option is now consistent between the mips remote
6644 target, remote targets using the gdb-specific protocol, UDI (AMD's
6645 debug protocol for the 29k) and the 88k bug monitor. It is now an
6646 integer specifying a debug level (normally 0 or 1, but 2 means more
6647 debugging info for the mips target).
6649 * DEC Alpha native support
6651 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6652 debug info, but GDB works fairly well with the DEC compiler and should
6653 work with a future GCC release. See the README file for a few
6654 Alpha-specific notes.
6656 * Preliminary thread implementation
6658 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6660 * LynxOS native and target support for 386
6662 This release has been hosted on LynxOS 2.2, and also can be configured
6663 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6666 * Improvements in C++ mangling/demangling.
6668 This release has much better g++ debugging, specifically in name
6669 mangling/demangling, virtual function calls, print virtual table,
6670 call methods, ...etc.
6672 *** Changes in GDB-4.10:
6674 * User visible changes:
6676 Remote debugging using the GDB-specific (`target remote') protocol now
6677 supports the `load' command. This is only useful if you have some
6678 other way of getting the stub to the target system, and you can put it
6679 somewhere in memory where it won't get clobbered by the download.
6681 Filename completion now works.
6683 When run under emacs mode, the "info line" command now causes the
6684 arrow to point to the line specified. Also, "info line" prints
6685 addresses in symbolic form (as well as hex).
6687 All vxworks based targets now support a user settable option, called
6688 vxworks-timeout. This option represents the number of seconds gdb
6689 should wait for responses to rpc's. You might want to use this if
6690 your vxworks target is, perhaps, a slow software simulator or happens
6691 to be on the far side of a thin network line.
6695 This release contains support for using a DEC alpha as a GDB host for
6696 cross debugging. Native alpha debugging is not supported yet.
6699 *** Changes in GDB-4.9:
6703 This is the first GDB release which is accompanied by a matching testsuite.
6704 The testsuite requires installation of dejagnu, which should be available
6705 via ftp from most sites that carry GNU software.
6709 'Cfront' style demangling has had its name changed to 'ARM' style, to
6710 emphasize that it was written from the specifications in the C++ Annotated
6711 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6712 disclaimers, it still generated too much confusion with users attempting to
6713 use gdb with AT&T cfront.
6717 GDB now uses a standard remote interface to a simulator library.
6718 So far, the library contains simulators for the Zilog Z8001/2, the
6719 Hitachi H8/300, H8/500 and Super-H.
6721 * New targets supported
6723 H8/300 simulator h8300-hitachi-hms or h8300hms
6724 H8/500 simulator h8500-hitachi-hms or h8500hms
6725 SH simulator sh-hitachi-hms or sh
6726 Z8000 simulator z8k-zilog-none or z8ksim
6727 IDT MIPS board over serial line mips-idt-ecoff
6729 Cross-debugging to GO32 targets is supported. It requires a custom
6730 version of the i386-stub.c module which is integrated with the
6731 GO32 memory extender.
6733 * New remote protocols
6735 MIPS remote debugging protocol.
6737 * New source languages supported
6739 This version includes preliminary support for Chill, a Pascal like language
6740 used by telecommunications companies. Chill support is also being integrated
6741 into the GNU compiler, but we don't know when it will be publically available.
6744 *** Changes in GDB-4.8:
6746 * HP Precision Architecture supported
6748 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6749 version of this support was available as a set of patches from the
6750 University of Utah. GDB does not support debugging of programs
6751 compiled with the HP compiler, because HP will not document their file
6752 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6753 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6755 Many problems in the preliminary version have been fixed.
6757 * Faster and better demangling
6759 We have improved template demangling and fixed numerous bugs in the GNU style
6760 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6761 character types (wchar_t) are now supported. Demangling of each symbol is now
6762 only done once, and is cached when the symbol table for a file is read in.
6763 This results in a small increase in memory usage for C programs, a moderate
6764 increase in memory usage for C++ programs, and a fantastic speedup in
6767 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6768 from the specifications in the Annotated Reference Manual, which AT&T's
6769 compiler does not actually implement.
6771 * G++ multiple inheritance compiler problem
6773 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6774 inheritance lattices was reworked to properly discover ambiguities. We
6775 recently found an example which causes this new algorithm to fail in a
6776 very subtle way, producing bad debug information for those classes.
6777 The file 'gcc.patch' (in this directory) can be applied to gcc to
6778 circumvent the problem. A future GCC release will contain a complete
6781 The previous G++ debug info problem (mentioned below for the gdb-4.7
6782 release) is fixed in gcc version 2.3.2.
6784 * Improved configure script
6786 The `configure' script will now attempt to guess your system type if
6787 you don't supply a host system type. The old scheme of supplying a
6788 host system triplet is preferable over using this. All the magic is
6789 done in the new `config.guess' script. Examine it for details.
6791 We have also brought our configure script much more in line with the FSF's
6792 version. It now supports the --with-xxx options. In particular,
6793 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6794 The resulting GDB will not be able to read arbitrary object file formats --
6795 only the format ``expected'' to be used on the configured target system.
6796 We hope to make this the default in a future release.
6798 * Documentation improvements
6800 There's new internal documentation on how to modify GDB, and how to
6801 produce clean changes to the code. We implore people to read it
6802 before submitting changes.
6804 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6805 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6806 `info' files are also provided. To build `info' files from scratch,
6807 you will need the latest `makeinfo' release, which will be available in
6808 a future texinfo-X.Y release.
6810 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6811 We're not sure exactly which versions have this problem, but it has
6812 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6813 or better. If that isn't possible, there is a patch in
6814 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6815 around this problem.
6819 GDB now supports array constants that can be used in expressions typed in by
6820 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6821 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6824 The new directory `gdb/sparclite' contains a program that demonstrates
6825 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6827 * New native hosts supported
6829 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6830 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6832 * New targets supported
6834 AMD 29k family via UDI a29k-amd-udi or udi29k
6836 * New file formats supported
6838 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6839 HPUX core files, and SCO 3.2v2 core files.
6843 Attaching to processes now works again; thanks for the many bug reports.
6845 We have also stomped on a bunch of core dumps caused by
6846 printf_filtered("%s") problems.
6848 We eliminated a copyright problem on the rpc and ptrace header files
6849 for VxWorks, which was discovered at the last minute during the 4.7
6850 release. You should now be able to build a VxWorks GDB.
6852 You can now interrupt gdb while an attached process is running. This
6853 will cause the attached process to stop, and give control back to GDB.
6855 We fixed problems caused by using too many file descriptors
6856 for reading symbols from object files and libraries. This was
6857 especially a problem for programs that used many (~100) shared
6860 The `step' command now only enters a subroutine if there is line number
6861 information for the subroutine. Otherwise it acts like the `next'
6862 command. Previously, `step' would enter subroutines if there was
6863 any debugging information about the routine. This avoids problems
6864 when using `cc -g1' on MIPS machines.
6866 * Internal improvements
6868 GDB's internal interfaces have been improved to make it easier to support
6869 debugging of multiple languages in the future.
6871 GDB now uses a common structure for symbol information internally.
6872 Minimal symbols (derived from linkage symbols in object files), partial
6873 symbols (from a quick scan of debug information), and full symbols
6874 contain a common subset of information, making it easier to write
6875 shared code that handles any of them.
6877 * New command line options
6879 We now accept --silent as an alias for --quiet.
6883 The memory-mapped-malloc library is now licensed under the GNU Library
6884 General Public License.
6886 *** Changes in GDB-4.7:
6888 * Host/native/target split
6890 GDB has had some major internal surgery to untangle the support for
6891 hosts and remote targets. Now, when you configure GDB for a remote
6892 target, it will no longer load in all of the support for debugging
6893 local programs on the host. When fully completed and tested, this will
6894 ensure that arbitrary host/target combinations are possible.
6896 The primary conceptual shift is to separate the non-portable code in
6897 GDB into three categories. Host specific code is required any time GDB
6898 is compiled on that host, regardless of the target. Target specific
6899 code relates to the peculiarities of the target, but can be compiled on
6900 any host. Native specific code is everything else: it can only be
6901 built when the host and target are the same system. Child process
6902 handling and core file support are two common `native' examples.
6904 GDB's use of /proc for controlling Unix child processes is now cleaner.
6905 It has been split out into a single module under the `target_ops' vector,
6906 plus two native-dependent functions for each system that uses /proc.
6908 * New hosts supported
6910 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6911 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6912 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6914 * New targets supported
6916 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6917 68030 and CPU32 m68030-*-*, m68332-*-*
6919 * New native hosts supported
6921 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6922 (386bsd is not well tested yet)
6923 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6925 * New file formats supported
6927 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6928 supports reading of `a.out.adobe' object files, which are an a.out
6929 format extended with minimal information about multiple sections.
6933 `show copying' is the same as the old `info copying'.
6934 `show warranty' is the same as `info warrantee'.
6935 These were renamed for consistency. The old commands continue to work.
6937 `info handle' is a new alias for `info signals'.
6939 You can now define pre-command hooks, which attach arbitrary command
6940 scripts to any command. The commands in the hook will be executed
6941 prior to the user's command. You can also create a hook which will be
6942 executed whenever the program stops. See gdb.texinfo.
6946 We now deal with Cfront style name mangling, and can even extract type
6947 info from mangled symbols. GDB can automatically figure out which
6948 symbol mangling style your C++ compiler uses.
6950 Calling of methods and virtual functions has been improved as well.
6954 The crash that occured when debugging Sun Ansi-C compiled binaries is
6955 fixed. This was due to mishandling of the extra N_SO stabs output
6958 We also finally got Ultrix 4.2 running in house, and fixed core file
6959 support, with help from a dozen people on the net.
6961 John M. Farrell discovered that the reason that single-stepping was so
6962 slow on all of the Mips based platforms (primarily SGI and DEC) was
6963 that we were trying to demangle and lookup a symbol used for internal
6964 purposes on every instruction that was being stepped through. Changing
6965 the name of that symbol so that it couldn't be mistaken for a C++
6966 mangled symbol sped things up a great deal.
6968 Rich Pixley sped up symbol lookups in general by getting much smarter
6969 about when C++ symbol mangling is necessary. This should make symbol
6970 completion (TAB on the command line) much faster. It's not as fast as
6971 we'd like, but it's significantly faster than gdb-4.6.
6975 A new user controllable variable 'call_scratch_address' can
6976 specify the location of a scratch area to be used when GDB
6977 calls a function in the target. This is necessary because the
6978 usual method of putting the scratch area on the stack does not work
6979 in systems that have separate instruction and data spaces.
6981 We integrated changes to support the 29k UDI (Universal Debugger
6982 Interface), but discovered at the last minute that we didn't have all
6983 of the appropriate copyright paperwork. We are working with AMD to
6984 resolve this, and hope to have it available soon.
6988 We have sped up the remote serial line protocol, especially for targets
6989 with lots of registers. It now supports a new `expedited status' ('T')
6990 message which can be used in place of the existing 'S' status message.
6991 This allows the remote stub to send only the registers that GDB
6992 needs to make a quick decision about single-stepping or conditional
6993 breakpoints, eliminating the need to fetch the entire register set for
6994 each instruction being stepped through.
6996 The GDB remote serial protocol now implements a write-through cache for
6997 registers, only re-reading the registers if the target has run.
6999 There is also a new remote serial stub for SPARC processors. You can
7000 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7001 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7002 processor with a serial port.
7006 Configure.in files have become much easier to read and modify. A new
7007 `table driven' format makes it more obvious what configurations are
7008 supported, and what files each one uses.
7012 There is a new opcodes library which will eventually contain all of the
7013 disassembly routines and opcode tables. At present, it only contains
7014 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7015 disassembler (binutils/objdump) to share these routines.
7017 The libiberty library is now copylefted under the GNU Library General
7018 Public License. This allows more liberal use, and was done so libg++
7019 can use it. This makes no difference to GDB, since the Library License
7020 grants all the rights from the General Public License.
7024 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7025 reference to the stabs symbol info used by the debugger. It is (as far
7026 as we know) the only published document on this fascinating topic. We
7027 encourage you to read it, compare it to the stabs information on your
7028 system, and send improvements on the document in general (to
7029 bug-gdb@prep.ai.mit.edu).
7031 And, of course, many bugs have been fixed.
7034 *** Changes in GDB-4.6:
7036 * Better support for C++ function names
7038 GDB now accepts as input the "demangled form" of C++ overloaded function
7039 names and member function names, and can do command completion on such names
7040 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7041 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7042 Make use of command completion, it is your friend.
7044 GDB also now accepts a variety of C++ mangled symbol formats. They are
7045 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7046 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7047 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7048 for the list of formats.
7050 * G++ symbol mangling problem
7052 Recent versions of gcc have a bug in how they emit debugging information for
7053 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7054 directory) can be applied to gcc to fix the problem. Alternatively, if you
7055 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7056 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7057 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7060 * New 'maintenance' command
7062 All of the commands related to hacking GDB internals have been moved out of
7063 the main command set, and now live behind the 'maintenance' command. This
7064 can also be abbreviated as 'mt'. The following changes were made:
7066 dump-me -> maintenance dump-me
7067 info all-breakpoints -> maintenance info breakpoints
7068 printmsyms -> maintenance print msyms
7069 printobjfiles -> maintenance print objfiles
7070 printpsyms -> maintenance print psymbols
7071 printsyms -> maintenance print symbols
7073 The following commands are new:
7075 maintenance demangle Call internal GDB demangler routine to
7076 demangle a C++ link name and prints the result.
7077 maintenance print type Print a type chain for a given symbol
7079 * Change to .gdbinit file processing
7081 We now read the $HOME/.gdbinit file before processing the argv arguments
7082 (e.g. reading symbol files or core files). This allows global parameters to
7083 be set, which will apply during the symbol reading. The ./.gdbinit is still
7084 read after argv processing.
7086 * New hosts supported
7088 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7090 GNU/Linux support i386-unknown-linux or linux
7092 We are also including code to support the HP/PA running BSD and HPUX. This
7093 is almost guaranteed not to work, as we didn't have time to test or build it
7094 for this release. We are including it so that the more adventurous (or
7095 masochistic) of you can play with it. We also had major problems with the
7096 fact that the compiler that we got from HP doesn't support the -g option.
7099 * New targets supported
7101 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7103 * More smarts about finding #include files
7105 GDB now remembers the compilation directory for all include files, and for
7106 all files from which C is generated (like yacc and lex sources). This
7107 greatly improves GDB's ability to find yacc/lex sources, and include files,
7108 especially if you are debugging your program from a directory different from
7109 the one that contains your sources.
7111 We also fixed a bug which caused difficulty with listing and setting
7112 breakpoints in include files which contain C code. (In the past, you had to
7113 try twice in order to list an include file that you hadn't looked at before.)
7115 * Interesting infernals change
7117 GDB now deals with arbitrary numbers of sections, where the symbols for each
7118 section must be relocated relative to that section's landing place in the
7119 target's address space. This work was needed to support ELF with embedded
7120 stabs used by Solaris-2.0.
7122 * Bug fixes (of course!)
7124 There have been loads of fixes for the following things:
7125 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7126 i960, stabs, DOS(GO32), procfs, etc...
7128 See the ChangeLog for details.
7130 *** Changes in GDB-4.5:
7132 * New machines supported (host and target)
7134 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7136 SGI Irix-4.x mips-sgi-irix4 or iris4
7138 * New malloc package
7140 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7141 Mmalloc is capable of handling mutiple heaps of memory. It is also
7142 capable of saving a heap to a file, and then mapping it back in later.
7143 This can be used to greatly speedup the startup of GDB by using a
7144 pre-parsed symbol table which lives in a mmalloc managed heap. For
7145 more details, please read mmalloc/mmalloc.texi.
7149 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7150 'help info proc' for details.
7152 * MIPS ecoff symbol table format
7154 The code that reads MIPS symbol table format is now supported on all hosts.
7155 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7158 * File name changes for MS-DOS
7160 Many files in the config directories have been renamed to make it easier to
7161 support GDB on MS-DOSe systems (which have very restrictive file name
7162 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7163 environment) is close to working but has some remaining problems. Note
7164 that debugging of DOS programs is not supported, due to limitations
7165 in the ``operating system'', but it can be used to host cross-debugging.
7167 * Cross byte order fixes
7169 Many fixes have been made to support cross debugging of Sparc and MIPS
7170 targets from hosts whose byte order differs.
7172 * New -mapped and -readnow options
7174 If memory-mapped files are available on your system through the 'mmap'
7175 system call, you can use the -mapped option on the `file' or
7176 `symbol-file' commands to cause GDB to write the symbols from your
7177 program into a reusable file. If the program you are debugging is
7178 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7179 Future GDB debugging sessions will notice the presence of this file,
7180 and will quickly map in symbol information from it, rather than reading
7181 the symbol table from the executable program. Using the '-mapped'
7182 option in a GDB `file' or `symbol-file' command has the same effect as
7183 starting GDB with the '-mapped' command-line option.
7185 You can cause GDB to read the entire symbol table immediately by using
7186 the '-readnow' option with any of the commands that load symbol table
7187 information (or on the GDB command line). This makes the command
7188 slower, but makes future operations faster.
7190 The -mapped and -readnow options are typically combined in order to
7191 build a `fred.syms' file that contains complete symbol information.
7192 A simple GDB invocation to do nothing but build a `.syms' file for future
7195 gdb -batch -nx -mapped -readnow programname
7197 The `.syms' file is specific to the host machine on which GDB is run.
7198 It holds an exact image of GDB's internal symbol table. It cannot be
7199 shared across multiple host platforms.
7201 * longjmp() handling
7203 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7204 siglongjmp() without losing control. This feature has not yet been ported to
7205 all systems. It currently works on many 386 platforms, all MIPS-based
7206 platforms (SGI, DECstation, etc), and Sun3/4.
7210 Preliminary work has been put in to support the new Solaris OS from Sun. At
7211 this time, it can control and debug processes, but it is not capable of
7216 As always, many many bug fixes. The major areas were with g++, and mipsread.
7217 People using the MIPS-based platforms should experience fewer mysterious
7218 crashes and trashed symbol tables.
7220 *** Changes in GDB-4.4:
7222 * New machines supported (host and target)
7224 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7226 BSD Reno on Vax vax-dec-bsd
7227 Ultrix on Vax vax-dec-ultrix
7229 * New machines supported (target)
7231 AMD 29000 embedded, using EBMON a29k-none-none
7235 GDB continues to improve its handling of C++. `References' work better.
7236 The demangler has also been improved, and now deals with symbols mangled as
7237 per the Annotated C++ Reference Guide.
7239 GDB also now handles `stabs' symbol information embedded in MIPS
7240 `ecoff' symbol tables. Since the ecoff format was not easily
7241 extensible to handle new languages such as C++, this appeared to be a
7242 good way to put C++ debugging info into MIPS binaries. This option
7243 will be supported in the GNU C compiler, version 2, when it is
7246 * New features for SVR4
7248 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7249 shared libraries. Debugging dynamically linked programs should present
7250 only minor differences from debugging statically linked programs.
7252 The `info proc' command will print out information about any process
7253 on an SVR4 system (including the one you are debugging). At the moment,
7254 it prints the address mappings of the process.
7256 If you bring up GDB on another SVR4 system, please send mail to
7257 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7259 * Better dynamic linking support in SunOS
7261 Reading symbols from shared libraries which contain debugging symbols
7262 now works properly. However, there remain issues such as automatic
7263 skipping of `transfer vector' code during function calls, which
7264 make it harder to debug code in a shared library, than to debug the
7265 same code linked statically.
7269 GDB is now using the latest `getopt' routines from the FSF. This
7270 version accepts the -- prefix for options with long names. GDB will
7271 continue to accept the old forms (-option and +option) as well.
7272 Various single letter abbreviations for options have been explicity
7273 added to the option table so that they won't get overshadowed in the
7274 future by other options that begin with the same letter.
7278 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7279 Many assorted bugs have been handled. Many more remain to be handled.
7280 See the various ChangeLog files (primarily in gdb and bfd) for details.
7283 *** Changes in GDB-4.3:
7285 * New machines supported (host and target)
7287 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7288 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7289 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7291 * Almost SCO Unix support
7293 We had hoped to support:
7294 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7295 (except for core file support), but we discovered very late in the release
7296 that it has problems with process groups that render gdb unusable. Sorry
7297 about that. I encourage people to fix it and post the fixes.
7299 * Preliminary ELF and DWARF support
7301 GDB can read ELF object files on System V Release 4, and can handle
7302 debugging records for C, in DWARF format, in ELF files. This support
7303 is preliminary. If you bring up GDB on another SVR4 system, please
7304 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7309 GDB now uses the latest `readline' library. One user-visible change
7310 is that two tabs will list possible command completions, which previously
7311 required typing M-? (meta-question mark, or ESC ?).
7315 The `stepi' bug that many of you noticed has been squashed.
7316 Many bugs in C++ have been handled. Many more remain to be handled.
7317 See the various ChangeLog files (primarily in gdb and bfd) for details.
7319 * State of the MIPS world (in case you wondered):
7321 GDB can understand the symbol tables emitted by the compilers
7322 supplied by most vendors of MIPS-based machines, including DEC. These
7323 symbol tables are in a format that essentially nobody else uses.
7325 Some versions of gcc come with an assembler post-processor called
7326 mips-tfile. This program is required if you want to do source-level
7327 debugging of gcc-compiled programs. I believe FSF does not ship
7328 mips-tfile with gcc version 1, but it will eventually come with gcc
7331 Debugging of g++ output remains a problem. g++ version 1.xx does not
7332 really support it at all. (If you're lucky, you should be able to get
7333 line numbers and stack traces to work, but no parameters or local
7334 variables.) With some work it should be possible to improve the
7337 When gcc version 2 is released, you will have somewhat better luck.
7338 However, even then you will get confusing results for inheritance and
7341 We will eventually provide full debugging of g++ output on
7342 DECstations. This will probably involve some kind of stabs-in-ecoff
7343 encapulation, but the details have not been worked out yet.
7346 *** Changes in GDB-4.2:
7348 * Improved configuration
7350 Only one copy of `configure' exists now, and it is not self-modifying.
7351 Porting BFD is simpler.
7355 The `step' and `next' commands now only stop at the first instruction
7356 of a source line. This prevents the multiple stops that used to occur
7357 in switch statements, for-loops, etc. `Step' continues to stop if a
7358 function that has debugging information is called within the line.
7362 Lots of small bugs fixed. More remain.
7364 * New host supported (not target)
7366 Intel 386 PC clone running Mach i386-none-mach
7369 *** Changes in GDB-4.1:
7371 * Multiple source language support
7373 GDB now has internal scaffolding to handle several source languages.
7374 It determines the type of each source file from its filename extension,
7375 and will switch expression parsing and number formatting to match the
7376 language of the function in the currently selected stack frame.
7377 You can also specifically set the language to be used, with
7378 `set language c' or `set language modula-2'.
7382 GDB now has preliminary support for the GNU Modula-2 compiler,
7383 currently under development at the State University of New York at
7384 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7385 continue through the fall of 1991 and into 1992.
7387 Other Modula-2 compilers are currently not supported, and attempting to
7388 debug programs compiled with them will likely result in an error as the
7389 symbol table is read. Feel free to work on it, though!
7391 There are hooks in GDB for strict type checking and range checking,
7392 in the `Modula-2 philosophy', but they do not currently work.
7396 GDB can now write to executable and core files (e.g. patch
7397 a variable's value). You must turn this switch on, specify
7398 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7399 by assigning a new value to a variable. Modifications take
7402 * Automatic SunOS shared library reading
7404 When you run your program, GDB automatically determines where its
7405 shared libraries (if any) have been loaded, and reads their symbols.
7406 The `share' command is no longer needed. This also works when
7407 examining core files.
7411 You can specify the number of lines that the `list' command shows.
7414 * New machines supported (host and target)
7416 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7417 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7418 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7420 * New hosts supported (not targets)
7422 IBM RT/PC: romp-ibm-aix or rtpc
7424 * New targets supported (not hosts)
7426 AMD 29000 embedded with COFF a29k-none-coff
7427 AMD 29000 embedded with a.out a29k-none-aout
7428 Ultracomputer remote kernel debug a29k-nyu-kern
7430 * New remote interfaces
7436 *** Changes in GDB-4.0:
7440 Wide output is wrapped at good places to make the output more readable.
7442 Gdb now supports cross-debugging from a host machine of one type to a
7443 target machine of another type. Communication with the target system
7444 is over serial lines. The ``target'' command handles connecting to the
7445 remote system; the ``load'' command will download a program into the
7446 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7447 also supports debugging of realtime processes running under VxWorks,
7448 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7449 stub on the target system.
7451 New CPUs supported include the AMD 29000 and Intel 960.
7453 GDB now reads object files and symbol tables via a ``binary file''
7454 library, which allows a single copy of GDB to debug programs of multiple
7455 object file types such as a.out and coff.
7457 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7458 refcard.dvi and refcard.ps are available to format it).
7461 * Control-Variable user interface simplified
7463 All variables that control the operation of the debugger can be set
7464 by the ``set'' command, and displayed by the ``show'' command.
7466 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7467 ``Show prompt'' produces the response:
7468 Gdb's prompt is new-gdb=>.
7470 What follows are the NEW set commands. The command ``help set'' will
7471 print a complete list of old and new set commands. ``help set FOO''
7472 will give a longer description of the variable FOO. ``show'' will show
7473 all of the variable descriptions and their current settings.
7475 confirm on/off: Enables warning questions for operations that are
7476 hard to recover from, e.g. rerunning the program while
7477 it is already running. Default is ON.
7479 editing on/off: Enables EMACS style command line editing
7480 of input. Previous lines can be recalled with
7481 control-P, the current line can be edited with control-B,
7482 you can search for commands with control-R, etc.
7485 history filename NAME: NAME is where the gdb command history
7486 will be stored. The default is .gdb_history,
7487 or the value of the environment variable
7490 history size N: The size, in commands, of the command history. The
7491 default is 256, or the value of the environment variable
7494 history save on/off: If this value is set to ON, the history file will
7495 be saved after exiting gdb. If set to OFF, the
7496 file will not be saved. The default is OFF.
7498 history expansion on/off: If this value is set to ON, then csh-like
7499 history expansion will be performed on
7500 command line input. The default is OFF.
7502 radix N: Sets the default radix for input and output. It can be set
7503 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7504 in the current radix, so "set radix 10" is always a no-op.
7506 height N: This integer value is the number of lines on a page. Default
7507 is 24, the current `stty rows'' setting, or the ``li#''
7508 setting from the termcap entry matching the environment
7511 width N: This integer value is the number of characters on a line.
7512 Default is 80, the current `stty cols'' setting, or the ``co#''
7513 setting from the termcap entry matching the environment
7516 Note: ``set screensize'' is obsolete. Use ``set height'' and
7517 ``set width'' instead.
7519 print address on/off: Print memory addresses in various command displays,
7520 such as stack traces and structure values. Gdb looks
7521 more ``symbolic'' if you turn this off; it looks more
7522 ``machine level'' with it on. Default is ON.
7524 print array on/off: Prettyprint arrays. New convenient format! Default
7527 print demangle on/off: Print C++ symbols in "source" form if on,
7530 print asm-demangle on/off: Same, for assembler level printouts
7533 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7536 * Support for Epoch Environment.
7538 The epoch environment is a version of Emacs v18 with windowing. One
7539 new command, ``inspect'', is identical to ``print'', except that if you
7540 are running in the epoch environment, the value is printed in its own
7544 * Support for Shared Libraries
7546 GDB can now debug programs and core files that use SunOS shared libraries.
7547 Symbols from a shared library cannot be referenced
7548 before the shared library has been linked with the program (this
7549 happens after you type ``run'' and before the function main() is entered).
7550 At any time after this linking (including when examining core files
7551 from dynamically linked programs), gdb reads the symbols from each
7552 shared library when you type the ``sharedlibrary'' command.
7553 It can be abbreviated ``share''.
7555 sharedlibrary REGEXP: Load shared object library symbols for files
7556 matching a unix regular expression. No argument
7557 indicates to load symbols for all shared libraries.
7559 info sharedlibrary: Status of loaded shared libraries.
7564 A watchpoint stops execution of a program whenever the value of an
7565 expression changes. Checking for this slows down execution
7566 tremendously whenever you are in the scope of the expression, but is
7567 quite useful for catching tough ``bit-spreader'' or pointer misuse
7568 problems. Some machines such as the 386 have hardware for doing this
7569 more quickly, and future versions of gdb will use this hardware.
7571 watch EXP: Set a watchpoint (breakpoint) for an expression.
7573 info watchpoints: Information about your watchpoints.
7575 delete N: Deletes watchpoint number N (same as breakpoints).
7576 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7577 enable N: Re-enables watchpoint number N (same as breakpoints).
7580 * C++ multiple inheritance
7582 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7585 * C++ exception handling
7587 Gdb now supports limited C++ exception handling. Besides the existing
7588 ability to breakpoint on an exception handler, gdb can breakpoint on
7589 the raising of an exception (before the stack is peeled back to the
7592 catch FOO: If there is a FOO exception handler in the dynamic scope,
7593 set a breakpoint to catch exceptions which may be raised there.
7594 Multiple exceptions (``catch foo bar baz'') may be caught.
7596 info catch: Lists all exceptions which may be caught in the
7597 current stack frame.
7600 * Minor command changes
7602 The command ``call func (arg, arg, ...)'' now acts like the print
7603 command, except it does not print or save a value if the function's result
7604 is void. This is similar to dbx usage.
7606 The ``up'' and ``down'' commands now always print the frame they end up
7607 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7608 frames without printing.
7610 * New directory command
7612 'dir' now adds directories to the FRONT of the source search path.
7613 The path starts off empty. Source files that contain debug information
7614 about the directory in which they were compiled can be found even
7615 with an empty path; Sun CC and GCC include this information. If GDB can't
7616 find your source file in the current directory, type "dir .".
7618 * Configuring GDB for compilation
7620 For normal use, type ``./configure host''. See README or gdb.texinfo
7623 GDB now handles cross debugging. If you are remotely debugging between
7624 two different machines, type ``./configure host -target=targ''.
7625 Host is the machine where GDB will run; targ is the machine
7626 where the program that you are debugging will run.