1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.3
6 * 'thread-exited' event is now available in the annotations interface.
8 * New built-in convenience variables $_gdb_major and $_gdb_minor
9 provide the GDB version. They are handy for conditionally using
10 features available only in or since specific GDB versions, in
11 scripts that should work error-free with many different versions,
12 such as in system-wide init files.
14 * GDB now supports Thread Local Storage (TLS) variables on several
15 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
16 architectures require kernel changes. TLS is not yet supported for
17 amd64 and i386 process core dumps.
19 * Support for Pointer Authentication on AArch64 Linux.
21 * Two new convenience functions $_cimag and $_creal that extract the
22 imaginary and real parts respectively from complex numbers.
24 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
25 provide the exitcode or exit status of the shell commands launched by
26 GDB commands such as "shell", "pipe" and "make".
30 ** The gdb.Value type has a new method 'format_string' which returns a
31 string representing the value. The formatting is controlled by the
32 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
33 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
34 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
36 ** gdb.Type has a new property 'objfile' which returns the objfile the
41 | [COMMAND] | SHELL_COMMAND
42 | -d DELIM COMMAND DELIM SHELL_COMMAND
43 pipe [COMMAND] | SHELL_COMMAND
44 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
45 Executes COMMAND and sends its output to SHELL_COMMAND.
46 With no COMMAND, repeat the last executed command
47 and send its output to SHELL_COMMAND.
49 with SETTING [VALUE] [-- COMMAND]
50 w SETTING [VALUE] [-- COMMAND]
51 Temporarily set SETTING, run COMMAND, and restore SETTING.
52 Usage: with SETTING -- COMMAND
53 With no COMMAND, repeats the last executed command.
54 SETTING is any GDB setting you can change with the "set"
55 subcommands. For example, 'with language c -- print someobj'
56 temporarily switches to the C language in order to print someobj.
57 Settings can be combined: 'w lang c -- w print elements unlimited --
58 usercmd' switches to the C language and runs usercmd with no limit
59 of array elements to print.
61 maint with SETTING [VALUE] [-- COMMAND]
62 Like "with", but works with "maintenance set" settings.
64 set may-call-functions [on|off]
65 show may-call-functions
66 This controls whether GDB will attempt to call functions in
67 the program, such as with expressions in the print command. It
68 defaults to on. Calling functions in the program being debugged
69 can have undesired side effects. It is now possible to forbid
70 such function calls. If function calls are forbidden, GDB will throw
71 an error when a command (such as print expression) calls a function
74 set print finish [on|off]
76 This controls whether the `finish' command will display the value
77 that is returned by the current function. When `off', the value is
78 still entered into the value history, but it is not printed. The
83 Allows deeply nested structures to be simplified when printing by
84 replacing deeply nested parts (beyond the max-depth) with ellipses.
85 The default max-depth is 20, but this can be set to unlimited to get
86 the old behavior back.
88 set logging debugredirect [on|off]
89 By default, GDB debug output will go to both the terminal and the logfile.
90 Set if you want debug output to go only to the log file.
92 set style title foreground COLOR
93 set style title background COLOR
94 set style title intensity VALUE
95 Control the styling of titles.
97 set style highlight foreground COLOR
98 set style highlight background COLOR
99 set style highlight intensity VALUE
100 Control the styling of highlightings.
102 maint set test-settings KIND
103 maint show test-settings KIND
104 A set of commands used by the testsuite for exercising the settings
110 The "help" command uses the title style to enhance the
111 readibility of its output by styling the classes and
115 Similarly to "help", the "apropos" command also uses the
116 title style for the command names. "apropos" accepts now
117 a flag "-v" (verbose) to show the full documentation
118 of matching commands and to use the highlight style to mark
119 the documentation parts matching REGEXP.
122 The "show style" and its subcommands are now styling
123 a style name in their output using its own style, to help
124 the user visualize the different styles.
126 set print raw-frame-arguments
127 show print raw-frame-arguments
129 These commands replace the similarly-named "set/show print raw
130 frame-arguments" commands (now with a dash instead of a space). The
131 old commands are now deprecated and may be removed in a future
134 maint test-options require-delimiter
135 maint test-options unknown-is-error
136 maint test-options unknown-is-operand
137 maint show test-options-completion-result
138 Commands used by the testsuite to validate the command options
141 * New command options, command completion
143 GDB now has a standard infrastructure to support dash-style command
144 options ('-OPT'). One benefit is that commands that use it can
145 easily support completion of command line arguments. Try "CMD
146 -[TAB]" or "help CMD" to find options supported by a command. Over
147 time, we intend to migrate most commands to this infrastructure. A
148 number of commands got support for new command options in this
151 ** The "print" and "compile print" commands now support a number of
152 options that allow overriding relevant global print settings as
153 set by "set print" subcommands:
157 -array-indexes [on|off]
158 -elements NUMBER|unlimited
162 -repeats NUMBER|unlimited
163 -static-members [on|off]
168 Note that because the "print"/"compile print" commands accept
169 arbitrary expressions which may look like options (including
170 abbreviations), if you specify any command option, then you must
171 use a double dash ("--") to mark the end of argument processing.
173 ** The "backtrace" command now supports a number of options that
174 allow overriding relevant global print settings as set by "set
175 backtrace" and "set print" subcommands:
177 -entry-values no|only|preferred|if-needed|both|compact|default
178 -frame-arguments all|scalars|none
179 -raw-frame-arguments [on|off]
183 In addition, the full/no-filters/hide qualifiers are now also
184 exposed as command options too:
190 ** The "frame apply", "tfaas" and "faas" commands similarly now
191 support the following options:
196 All options above can also be abbreviated. The argument of boolean
197 (on/off) options can be 0/1 too, and also the argument is assumed
198 "on" if omitted. This allows writing compact command invocations,
201 (gdb) p -r -p -o 0 -- *myptr
203 The above is equivalent to:
205 (gdb) print -raw -pretty -object off -- *myptr
207 * Completion improvements
209 ** GDB can now complete the options of the "thread apply all" and
210 "taas" commands, and their "-ascending" option can now be
213 ** GDB can now complete the options of the "info threads" command.
215 ** GDB can now complete the options of the "compile file" and
216 "compile code" commands. The "compile file" command now
217 completes on filenames.
219 ** GDB can now complete the backtrace command's
220 "full/no-filters/hide" qualifiers.
222 * In settings, you can now abbreviate "unlimited".
224 E.g., "set print elements u" is now equivalent to "set print
230 This lists all the possible completions for the rest of the line, if it
231 were to be given as a command itself. This is intended for use by MI
232 frontends in cases when separate CLI and MI channels cannot be used.
234 -catch-throw, -catch-rethrow, and -catch-catch
235 These can be used to catch C++ exceptions in a similar fashion to
236 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
240 The testsuite now creates the files gdb.cmd (containing the arguments
241 used to launch GDB) and gdb.in (containing all the commands sent to
242 GDB) in the output directory for each test script. Multiple invocations
243 are appended with .1, .2, .3 etc.
245 *** Changes in GDB 8.3
247 * GDB and GDBserver now support access to additional registers on
248 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
251 * GDB now has experimental support for the compilation and injection of
252 C++ source code into the inferior. This beta release does not include
253 support for several language features, such as templates, constructors,
256 This feature requires GCC 7.1 or higher built with libcp1.so
259 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
260 can be passed using the '[ADDRESS]:PORT' notation, or the regular
261 'ADDRESS:PORT' method.
263 * DWARF index cache: GDB can now automatically save indices of DWARF
264 symbols on disk to speed up further loading of the same binaries.
266 * Ada task switching is now supported on aarch64-elf targets when
267 debugging a program using the Ravenscar Profile. For more information,
268 see the "Tasking Support when using the Ravenscar Profile" section
269 in the GDB user manual.
271 * GDB in batch mode now exits with status 1 if the last command to be
274 * The RISC-V target now supports target descriptions.
276 * System call catchpoints now support system call aliases on FreeBSD.
277 When the ABI of a system call changes in FreeBSD, this is
278 implemented by leaving a compatibility system call using the old ABI
279 at the existing number and allocating a new system call number for
280 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
281 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
282 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
283 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
284 so that a system call catchpoint for the 'kevent' system call will
285 catch invocations of both the 'kevent' and 'freebsd11_kevent'
286 binaries. This ensures that 'kevent' system calls are caught for
287 binaries using either the old or new ABIs.
289 * Terminal styling is now available for the CLI and the TUI. GNU
290 Source Highlight can additionally be used to provide styling of
291 source code snippets. See the "set style" commands, below, for more
294 * Removed support for old demangling styles arm, edg, gnu, hp and
299 set debug compile-cplus-types
300 show debug compile-cplus-types
301 Control the display of debug output about type conversion in the
302 C++ compile feature. Commands have no effect while compiliong
307 Control whether debug output about files/functions skipping is
310 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
311 Apply a command to some frames.
312 FLAG arguments allow to control what output to produce and how to handle
313 errors raised when applying COMMAND to a frame.
316 Apply a command to all threads (ignoring errors and empty output).
317 Shortcut for 'thread apply all -s COMMAND'.
320 Apply a command to all frames (ignoring errors and empty output).
321 Shortcut for 'frame apply all -s COMMAND'.
324 Apply a command to all frames of all threads (ignoring errors and empty
326 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
328 maint set dwarf unwinders (on|off)
329 maint show dwarf unwinders
330 Control whether DWARF unwinders can be used.
333 Display a list of open files for a process.
337 Changes to the "frame", "select-frame", and "info frame" CLI commands.
338 These commands all now take a frame specification which
339 is either a frame level, or one of the keywords 'level', 'address',
340 'function', or 'view' followed by a parameter. Selecting a frame by
341 address, or viewing a frame outside the current backtrace now
342 requires the use of a keyword. Selecting a frame by level is
343 unchanged. The MI comment "-stack-select-frame" is unchanged.
345 target remote FILENAME
346 target extended-remote FILENAME
347 If FILENAME is a Unix domain socket, GDB will attempt to connect
348 to this socket instead of opening FILENAME as a character device.
350 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
351 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
352 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
353 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
354 These commands can now print only the searched entities
355 matching the provided regexp(s), giving a condition
356 on the entity names or entity types. The flag -q disables
357 printing headers or informations messages.
363 These commands now determine the syntax for the shown entities
364 according to the language chosen by `set language'. In particular,
365 `set language auto' means to automatically choose the language of
368 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
369 The 'thread apply' command accepts new FLAG arguments.
370 FLAG arguments allow to control what output to produce and how to handle
371 errors raised when applying COMMAND to a thread.
373 set tui tab-width NCHARS
374 show tui tab-width NCHARS
375 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
377 set style enabled [on|off]
379 Enable or disable terminal styling. Styling is enabled by default
380 on most hosts, but disabled by default when in batch mode.
382 set style sources [on|off]
384 Enable or disable source code styling. Source code styling is
385 enabled by default, but only takes effect if styling in general is
386 enabled, and if GDB was linked with GNU Source Highlight.
388 set style filename foreground COLOR
389 set style filename background COLOR
390 set style filename intensity VALUE
391 Control the styling of file names.
393 set style function foreground COLOR
394 set style function background COLOR
395 set style function intensity VALUE
396 Control the styling of function names.
398 set style variable foreground COLOR
399 set style variable background COLOR
400 set style variable intensity VALUE
401 Control the styling of variable names.
403 set style address foreground COLOR
404 set style address background COLOR
405 set style address intensity VALUE
406 Control the styling of addresses.
410 ** The default version of the MI interpreter is now 3 (-i=mi3).
412 ** The '-data-disassemble' MI command now accepts an '-a' option to
413 disassemble the whole function surrounding the given program
414 counter value or function name. Support for this feature can be
415 verified by using the "-list-features" command, which should
416 contain "data-disassemble-a-option".
418 ** Command responses and notifications that include a frame now include
419 the frame's architecture in a new "arch" attribute.
421 ** The output of information about multi-location breakpoints (which is
422 syntactically incorrect in MI 2) has changed in MI 3. This affects
423 the following commands and events:
427 - =breakpoint-created
428 - =breakpoint-modified
430 The -fix-multi-location-breakpoint-output command can be used to enable
431 this behavior with previous MI versions.
433 * New native configurations
435 GNU/Linux/RISC-V riscv*-*-linux*
436 FreeBSD/riscv riscv*-*-freebsd*
440 GNU/Linux/RISC-V riscv*-*-linux*
442 CSKY GNU/LINUX csky*-*-linux
443 FreeBSD/riscv riscv*-*-freebsd*
445 GNU/Linux/OpenRISC or1k*-*-linux*
449 GDB no longer supports native debugging on versions of MS-Windows
454 ** GDB no longer supports Python versions less than 2.6.
456 ** The gdb.Inferior type has a new 'progspace' property, which is the program
457 space associated to that inferior.
459 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
460 of objfiles associated to that program space.
462 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
463 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
466 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
467 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
468 correct and did not work properly.
470 ** The gdb.Value type has a new constructor, which is used to construct a
471 gdb.Value from a Python buffer object and a gdb.Type.
477 Enable or disable the undefined behavior sanitizer. This is
478 disabled by default, but passing --enable-ubsan=yes or
479 --enable-ubsan=auto to configure will enable it. Enabling this can
480 cause a performance penalty. The undefined behavior sanitizer was
481 first introduced in GCC 4.9.
483 *** Changes in GDB 8.2
485 * The 'set disassembler-options' command now supports specifying options
488 * The 'symbol-file' command now accepts an '-o' option to add a relative
489 offset to all sections.
491 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
492 a relative offset to all sections, but it allows to override the load
493 address of individual sections using '-s'.
495 * The 'add-symbol-file' command no longer requires the second argument
496 (address of the text section).
498 * The endianness used with the 'set endian auto' mode in the absence of
499 an executable selected for debugging is now the last endianness chosen
500 either by one of the 'set endian big' and 'set endian little' commands
501 or by inferring from the last executable used, rather than the startup
504 * The pager now allows a "c" response, meaning to disable the pager
505 for the rest of the current command.
507 * The commands 'info variables/functions/types' now show the source line
508 numbers of symbol definitions when available.
510 * 'info proc' now works on running processes on FreeBSD systems and core
511 files created on FreeBSD systems.
513 * C expressions can now use _Alignof, and C++ expressions can now use
516 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
517 the vector length while the process is running.
523 Control display of debugging info regarding the FreeBSD native target.
525 set|show varsize-limit
526 This new setting allows the user to control the maximum size of Ada
527 objects being printed when those objects have a variable type,
528 instead of that maximum size being hardcoded to 65536 bytes.
530 set|show record btrace cpu
531 Controls the processor to be used for enabling errata workarounds for
534 maint check libthread-db
535 Run integrity checks on the current inferior's thread debugging
538 maint set check-libthread-db (on|off)
539 maint show check-libthread-db
540 Control whether to run integrity checks on inferior specific thread
541 debugging libraries as they are loaded. The default is not to
546 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
548 ** The commands attached to a breakpoint can be set by assigning to
549 the breakpoint's "commands" field.
551 ** gdb.execute can now execute multi-line gdb commands.
553 ** The new functions gdb.convenience_variable and
554 gdb.set_convenience_variable can be used to get and set the value
555 of convenience variables.
557 ** A gdb.Parameter will no longer print the "set" help text on an
558 ordinary "set"; instead by default a "set" will be silent unless
559 the get_set_string method returns a non-empty string.
563 RiscV ELF riscv*-*-elf
565 * Removed targets and native configurations
567 m88k running OpenBSD m88*-*-openbsd*
568 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
569 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
570 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
572 * Aarch64/Linux hardware watchpoints improvements
574 Hardware watchpoints on unaligned addresses are now properly
575 supported when running Linux kernel 4.10 or higher: read and access
576 watchpoints are no longer spuriously missed, and all watchpoints
577 lengths between 1 and 8 bytes are supported. On older kernels,
578 watchpoints set on unaligned addresses are no longer missed, with
579 the tradeoff that there is a possibility of false hits being
584 --enable-codesign=CERT
585 This can be used to invoke "codesign -s CERT" after building gdb.
586 This option is useful on macOS, where code signing is required for
587 gdb to work properly.
589 --disable-gdbcli has been removed
590 This is now silently accepted, but does nothing.
592 *** Changes in GDB 8.1
594 * GDB now supports dynamically creating arbitrary register groups specified
595 in XML target descriptions. This allows for finer grain grouping of
596 registers on systems with a large amount of registers.
598 * The 'ptype' command now accepts a '/o' flag, which prints the
599 offsets and sizes of fields in a struct, like the pahole(1) tool.
601 * New "--readnever" command line option instructs GDB to not read each
602 symbol file's symbolic debug information. This makes startup faster
603 but at the expense of not being able to perform symbolic debugging.
604 This option is intended for use cases where symbolic debugging will
605 not be used, e.g., when you only need to dump the debuggee's core.
607 * GDB now uses the GNU MPFR library, if available, to emulate target
608 floating-point arithmetic during expression evaluation when the target
609 uses different floating-point formats than the host. At least version
610 3.1 of GNU MPFR is required.
612 * GDB now supports access to the guarded-storage-control registers and the
613 software-based guarded-storage broadcast control registers on IBM z14.
615 * On Unix systems, GDB now supports transmitting environment variables
616 that are to be set or unset to GDBserver. These variables will
617 affect the environment to be passed to the remote inferior.
619 To inform GDB of environment variables that are to be transmitted to
620 GDBserver, use the "set environment" command. Only user set
621 environment variables are sent to GDBserver.
623 To inform GDB of environment variables that are to be unset before
624 the remote inferior is started by the GDBserver, use the "unset
625 environment" command.
627 * Completion improvements
629 ** GDB can now complete function parameters in linespecs and
630 explicit locations without quoting. When setting breakpoints,
631 quoting around functions names to help with TAB-completion is
632 generally no longer necessary. For example, this now completes
635 (gdb) b function(in[TAB]
636 (gdb) b function(int)
638 Related, GDB is no longer confused with completing functions in
639 C++ anonymous namespaces:
642 (gdb) b (anonymous namespace)::[TAB][TAB]
643 (anonymous namespace)::a_function()
644 (anonymous namespace)::b_function()
646 ** GDB now has much improved linespec and explicit locations TAB
647 completion support, that better understands what you're
648 completing and offers better suggestions. For example, GDB no
649 longer offers data symbols as possible completions when you're
650 setting a breakpoint.
652 ** GDB now TAB-completes label symbol names.
654 ** The "complete" command now mimics TAB completion accurately.
656 * New command line options (gcore)
659 Dump all memory mappings.
661 * Breakpoints on C++ functions are now set on all scopes by default
663 By default, breakpoints on functions/methods are now interpreted as
664 specifying all functions with the given name ignoring missing
665 leading scopes (namespaces and classes).
667 For example, assuming a C++ program with symbols named:
672 both commands "break func()" and "break B::func()" set a breakpoint
675 You can use the new flag "-qualified" to override this. This makes
676 GDB interpret the specified function name as a complete
677 fully-qualified name instead. For example, using the same C++
678 program, the "break -q B::func" command sets a breakpoint on
679 "B::func", only. A parameter has been added to the Python
680 gdb.Breakpoint constructor to achieve the same result when creating
681 a breakpoint from Python.
683 * Breakpoints on functions marked with C++ ABI tags
685 GDB can now set breakpoints on functions marked with C++ ABI tags
686 (e.g., [abi:cxx11]). See here for a description of ABI tags:
687 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
689 Functions with a C++11 abi tag are demangled/displayed like this:
691 function[abi:cxx11](int)
694 You can now set a breakpoint on such functions simply as if they had
697 (gdb) b function(int)
699 Or if you need to disambiguate between tags, like:
701 (gdb) b function[abi:other_tag](int)
703 Tab completion was adjusted accordingly as well.
707 ** New events gdb.new_inferior, gdb.inferior_deleted, and
708 gdb.new_thread are emitted. See the manual for further
709 description of these.
711 ** A new function, "gdb.rbreak" has been added to the Python API.
712 This function allows the setting of a large number of breakpoints
713 via a regex pattern in Python. See the manual for further details.
715 ** Python breakpoints can now accept explicit locations. See the
716 manual for a further description of this feature.
719 * New features in the GDB remote stub, GDBserver
721 ** GDBserver is now able to start inferior processes with a
722 specified initial working directory.
724 The user can set the desired working directory to be used from
725 GDB using the new "set cwd" command.
727 ** New "--selftest" command line option runs some GDBserver self
728 tests. These self tests are disabled in releases.
730 ** On Unix systems, GDBserver now does globbing expansion and variable
731 substitution in inferior command line arguments.
733 This is done by starting inferiors using a shell, like GDB does.
734 See "set startup-with-shell" in the user manual for how to disable
735 this from GDB when using "target extended-remote". When using
736 "target remote", you can disable the startup with shell by using the
737 new "--no-startup-with-shell" GDBserver command line option.
739 ** On Unix systems, GDBserver now supports receiving environment
740 variables that are to be set or unset from GDB. These variables
741 will affect the environment to be passed to the inferior.
743 * When catching an Ada exception raised with a message, GDB now prints
744 the message in the catchpoint hit notification. In GDB/MI mode, that
745 information is provided as an extra field named "exception-message"
746 in the *stopped notification.
748 * Trait objects can now be inspected When debugging Rust code. This
749 requires compiler support which will appear in Rust 1.24.
753 QEnvironmentHexEncoded
754 Inform GDBserver of an environment variable that is to be passed to
755 the inferior when starting it.
758 Inform GDBserver of an environment variable that is to be unset
759 before starting the remote inferior.
762 Inform GDBserver that the environment should be reset (i.e.,
763 user-set environment variables should be unset).
766 Indicates whether the inferior must be started with a shell or not.
769 Tell GDBserver that the inferior to be started should use a specific
772 * The "maintenance print c-tdesc" command now takes an optional
773 argument which is the file name of XML target description.
775 * The "maintenance selftest" command now takes an optional argument to
776 filter the tests to be run.
778 * The "enable", and "disable" commands now accept a range of
779 breakpoint locations, e.g. "enable 1.3-5".
784 Set and show the current working directory for the inferior.
787 Set and show compilation command used for compiling and injecting code
788 with the 'compile' commands.
790 set debug separate-debug-file
791 show debug separate-debug-file
792 Control the display of debug output about separate debug file search.
794 set dump-excluded-mappings
795 show dump-excluded-mappings
796 Control whether mappings marked with the VM_DONTDUMP flag should be
797 dumped when generating a core file.
800 List the registered selftests.
803 Start the debugged program stopping at the first instruction.
806 Control display of debugging messages related to OpenRISC targets.
808 set|show print type nested-type-limit
809 Set and show the limit of nesting level for nested types that the
810 type printer will show.
812 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
815 * Safer/improved support for debugging with no debug info
817 GDB no longer assumes functions with no debug information return
820 This means that GDB now refuses to call such functions unless you
821 tell it the function's type, by either casting the call to the
822 declared return type, or by casting the function to a function
823 pointer of the right type, and calling that:
825 (gdb) p getenv ("PATH")
826 'getenv' has unknown return type; cast the call to its declared return type
827 (gdb) p (char *) getenv ("PATH")
828 $1 = 0x7fffffffe "/usr/local/bin:/"...
829 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
830 $2 = 0x7fffffffe "/usr/local/bin:/"...
832 Similarly, GDB no longer assumes that global variables with no debug
833 info have type 'int', and refuses to print the variable's value
834 unless you tell it the variable's type:
837 'var' has unknown type; cast it to its declared type
841 * New native configurations
843 FreeBSD/aarch64 aarch64*-*-freebsd*
844 FreeBSD/arm arm*-*-freebsd*
848 FreeBSD/aarch64 aarch64*-*-freebsd*
849 FreeBSD/arm arm*-*-freebsd*
850 OpenRISC ELF or1k*-*-elf
852 * Removed targets and native configurations
854 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
856 *** Changes in GDB 8.0
858 * GDB now supports access to the PKU register on GNU/Linux. The register is
859 added by the Memory Protection Keys for Userspace feature which will be
860 available in future Intel CPUs.
862 * GDB now supports C++11 rvalue references.
866 ** New functions to start, stop and access a running btrace recording.
867 ** Rvalue references are now supported in gdb.Type.
869 * GDB now supports recording and replaying rdrand and rdseed Intel 64
872 * Building GDB and GDBserver now requires a C++11 compiler.
874 For example, GCC 4.8 or later.
876 It is no longer possible to build GDB or GDBserver with a C
877 compiler. The --disable-build-with-cxx configure option has been
880 * Building GDB and GDBserver now requires GNU make >= 3.81.
882 It is no longer supported to build GDB or GDBserver with another
883 implementation of the make program or an earlier version of GNU make.
885 * Native debugging on MS-Windows supports command-line redirection
887 Command-line arguments used for starting programs on MS-Windows can
888 now include redirection symbols supported by native Windows shells,
889 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
890 as "run", "start", and "set args", as well as the corresponding MI
893 * Support for thread names on MS-Windows.
895 GDB now catches and handles the special exception that programs
896 running on MS-Windows use to assign names to threads in the
899 * Support for Java programs compiled with gcj has been removed.
901 * User commands now accept an unlimited number of arguments.
902 Previously, only up to 10 was accepted.
904 * The "eval" command now expands user-defined command arguments.
906 This makes it easier to process a variable number of arguments:
911 eval "print $arg%d", $i
916 * Target descriptions can now describe registers for sparc32 and sparc64.
918 * GDB now supports DWARF version 5 (debug information format).
919 Its .debug_names index is not yet supported.
921 * New native configurations
923 FreeBSD/mips mips*-*-freebsd
927 Synopsys ARC arc*-*-elf32
928 FreeBSD/mips mips*-*-freebsd
930 * Removed targets and native configurations
932 Alpha running FreeBSD alpha*-*-freebsd*
933 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
938 Erases all the flash memory regions reported by the target.
940 maint print arc arc-instruction address
941 Print internal disassembler information about instruction at a given address.
945 set disassembler-options
946 show disassembler-options
947 Controls the passing of target specific information to the disassembler.
948 If it is necessary to specify more than one disassembler option then
949 multiple options can be placed together into a comma separated list.
950 The default value is the empty string. Currently, the only supported
951 targets are ARM, PowerPC and S/390.
956 Erases all the flash memory regions reported by the target. This is
957 equivalent to the CLI command flash-erase.
959 -file-list-shared-libraries
960 List the shared libraries in the program. This is
961 equivalent to the CLI command "info shared".
964 Catchpoints stopping the program when Ada exceptions are
965 handled. This is equivalent to the CLI command "catch handlers".
967 *** Changes in GDB 7.12
969 * GDB and GDBserver now build with a C++ compiler by default.
971 The --enable-build-with-cxx configure option is now enabled by
972 default. One must now explicitly configure with
973 --disable-build-with-cxx in order to build with a C compiler. This
974 option will be removed in a future release.
976 * GDBserver now supports recording btrace without maintaining an active
979 * GDB now supports a negative repeat count in the 'x' command to examine
980 memory backward from the given address. For example:
983 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
984 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
985 (gdb) x/-5i 0x0000000000400580
986 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
987 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
988 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
989 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
990 0x40057b <main(int, char**)+25>:
991 callq 0x400536 <Func1(int, char const*)>
993 * Fortran: Support structures with fields of dynamic types and
994 arrays of dynamic types.
996 * The symbol dumping maintenance commands have new syntax.
997 maint print symbols [-pc address] [--] [filename]
998 maint print symbols [-objfile objfile] [-source source] [--] [filename]
999 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1000 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1001 maint print msymbols [-objfile objfile] [--] [filename]
1003 * GDB now supports multibit bitfields and enums in target register
1006 * New Python-based convenience function $_as_string(val), which returns
1007 the textual representation of a value. This function is especially
1008 useful to obtain the text label of an enum value.
1010 * Intel MPX bound violation handling.
1012 Segmentation faults caused by a Intel MPX boundary violation
1013 now display the kind of violation (upper or lower), the memory
1014 address accessed and the memory bounds, along with the usual
1015 signal received and code location.
1019 Program received signal SIGSEGV, Segmentation fault
1020 Upper bound violation while accessing address 0x7fffffffc3b3
1021 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1022 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1024 * Rust language support.
1025 GDB now supports debugging programs written in the Rust programming
1026 language. See https://www.rust-lang.org/ for more information about
1029 * Support for running interpreters on specified input/output devices
1031 GDB now supports a new mechanism that allows frontends to provide
1032 fully featured GDB console views, as a better alternative to
1033 building such views on top of the "-interpreter-exec console"
1034 command. See the new "new-ui" command below. With that command,
1035 frontends can now start GDB in the traditional command-line mode
1036 running in an embedded terminal emulator widget, and create a
1037 separate MI interpreter running on a specified i/o device. In this
1038 way, GDB handles line editing, history, tab completion, etc. in the
1039 console all by itself, and the GUI uses the separate MI interpreter
1040 for its own control and synchronization, invisible to the command
1043 * The "catch syscall" command catches groups of related syscalls.
1045 The "catch syscall" command now supports catching a group of related
1046 syscalls using the 'group:' or 'g:' prefix.
1051 skip -gfile file-glob-pattern
1052 skip -function function
1053 skip -rfunction regular-expression
1054 A generalized form of the skip command, with new support for
1055 glob-style file names and regular expressions for function names.
1056 Additionally, a file spec and a function spec may now be combined.
1058 maint info line-table REGEXP
1059 Display the contents of GDB's internal line table data struture.
1062 Run any GDB unit tests that were compiled in.
1065 Start a new user interface instance running INTERP as interpreter,
1066 using the TTY file for input/output.
1070 ** gdb.Breakpoint objects have a new attribute "pending", which
1071 indicates whether the breakpoint is pending.
1072 ** Three new breakpoint-related events have been added:
1073 gdb.breakpoint_created, gdb.breakpoint_modified, and
1074 gdb.breakpoint_deleted.
1076 signal-event EVENTID
1077 Signal ("set") the given MS-Windows event object. This is used in
1078 conjunction with the Windows JIT debugging (AeDebug) support, where
1079 the OS suspends a crashing process until a debugger can attach to
1080 it. Resuming the crashing process, in order to debug it, is done by
1081 signalling an event.
1083 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1084 was added in GDBserver, including JIT compiling fast tracepoint's
1085 conditional expression bytecode into native code.
1087 * Support for various remote target protocols and ROM monitors has
1090 target m32rsdi Remote M32R debugging over SDI
1091 target mips MIPS remote debugging protocol
1092 target pmon PMON ROM monitor
1093 target ddb NEC's DDB variant of PMON for Vr4300
1094 target rockhopper NEC RockHopper variant of PMON
1095 target lsi LSI variant of PMO
1097 * Support for tracepoints and fast tracepoints on powerpc-linux,
1098 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1099 including JIT compiling fast tracepoint's conditional expression
1100 bytecode into native code.
1102 * MI async record =record-started now includes the method and format used for
1103 recording. For example:
1105 =record-started,thread-group="i1",method="btrace",format="bts"
1107 * MI async record =thread-selected now includes the frame field. For example:
1109 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1113 Andes NDS32 nds32*-*-elf
1115 *** Changes in GDB 7.11
1117 * GDB now supports debugging kernel-based threads on FreeBSD.
1119 * Per-inferior thread numbers
1121 Thread numbers are now per inferior instead of global. If you're
1122 debugging multiple inferiors, GDB displays thread IDs using a
1123 qualified INF_NUM.THR_NUM form. For example:
1127 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1128 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1129 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1130 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1132 As consequence, thread numbers as visible in the $_thread
1133 convenience variable and in Python's InferiorThread.num attribute
1134 are no longer unique between inferiors.
1136 GDB now maintains a second thread ID per thread, referred to as the
1137 global thread ID, which is the new equivalent of thread numbers in
1138 previous releases. See also $_gthread below.
1140 For backwards compatibility, MI's thread IDs always refer to global
1143 * Commands that accept thread IDs now accept the qualified
1144 INF_NUM.THR_NUM form as well. For example:
1147 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1150 * In commands that accept a list of thread IDs, you can now refer to
1151 all threads of an inferior using a star wildcard. GDB accepts
1152 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1153 refer to all threads of the current inferior. For example, "info
1156 * You can use "info threads -gid" to display the global thread ID of
1159 * The new convenience variable $_gthread holds the global number of
1162 * The new convenience variable $_inferior holds the number of the
1165 * GDB now displays the ID and name of the thread that hit a breakpoint
1166 or received a signal, if your program is multi-threaded. For
1169 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1170 Thread 1 "main" received signal SIGINT, Interrupt.
1172 * Record btrace now supports non-stop mode.
1174 * Support for tracepoints on aarch64-linux was added in GDBserver.
1176 * The 'record instruction-history' command now indicates speculative execution
1177 when using the Intel Processor Trace recording format.
1179 * GDB now allows users to specify explicit locations, bypassing
1180 the linespec parser. This feature is also available to GDB/MI
1183 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1184 GDB now is able to debug both AArch64 applications and ARM applications
1187 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1188 including JIT compiling fast tracepoint's conditional expression bytecode
1191 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1193 * "info threads", "info inferiors", "info display", "info checkpoints"
1194 and "maint info program-spaces" now list the corresponding items in
1195 ascending ID order, for consistency with all other "info" commands.
1197 * In Ada, the overloads selection menu has been enhanced to display the
1198 parameter types and the return types for the matching overloaded subprograms.
1202 maint set target-non-stop (on|off|auto)
1203 maint show target-non-stop
1204 Control whether GDB targets always operate in non-stop mode even if
1205 "set non-stop" is "off". The default is "auto", meaning non-stop
1206 mode is enabled if supported by the target.
1208 maint set bfd-sharing
1209 maint show bfd-sharing
1210 Control the reuse of bfd objects.
1213 show debug bfd-cache
1214 Control display of debugging info regarding bfd caching.
1218 Control display of debugging info regarding FreeBSD threads.
1220 set remote multiprocess-extensions-packet
1221 show remote multiprocess-extensions-packet
1222 Set/show the use of the remote protocol multiprocess extensions.
1224 set remote thread-events
1225 show remote thread-events
1226 Set/show the use of thread create/exit events.
1228 set ada print-signatures on|off
1229 show ada print-signatures"
1230 Control whether parameter types and return types are displayed in overloads
1231 selection menus. It is activaled (@code{on}) by default.
1235 Controls the maximum size of memory, in bytes, that GDB will
1236 allocate for value contents. Prevents incorrect programs from
1237 causing GDB to allocate overly large buffers. Default is 64k.
1239 * The "disassemble" command accepts a new modifier: /s.
1240 It prints mixed source+disassembly like /m with two differences:
1241 - disassembled instructions are now printed in program order, and
1242 - and source for all relevant files is now printed.
1243 The "/m" option is now considered deprecated: its "source-centric"
1244 output hasn't proved useful in practice.
1246 * The "record instruction-history" command accepts a new modifier: /s.
1247 It behaves exactly like /m and prints mixed source+disassembly.
1249 * The "set scheduler-locking" command supports a new mode "replay".
1250 It behaves like "off" in record mode and like "on" in replay mode.
1252 * Support for various ROM monitors has been removed:
1254 target dbug dBUG ROM monitor for Motorola ColdFire
1255 target picobug Motorola picobug monitor
1256 target dink32 DINK32 ROM monitor for PowerPC
1257 target m32r Renesas M32R/D ROM monitor
1258 target mon2000 mon2000 ROM monitor
1259 target ppcbug PPCBUG ROM monitor for PowerPC
1261 * Support for reading/writing memory and extracting values on architectures
1262 whose memory is addressable in units of any integral multiple of 8 bits.
1265 Allows to break when an Ada exception is handled.
1267 * New remote packets
1270 Indicates that an exec system call was executed.
1272 exec-events feature in qSupported
1273 The qSupported packet allows GDB to request support for exec
1274 events using the new 'gdbfeature' exec-event, and the qSupported
1275 response can contain the corresponding 'stubfeature'. Set and
1276 show commands can be used to display whether these features are enabled.
1279 Equivalent to interrupting with the ^C character, but works in
1282 thread created stop reason (T05 create:...)
1283 Indicates that the thread was just created and is stopped at entry.
1285 thread exit stop reply (w exitcode;tid)
1286 Indicates that the thread has terminated.
1289 Enables/disables thread create and exit event reporting. For
1290 example, this is used in non-stop mode when GDB stops a set of
1291 threads and synchronously waits for the their corresponding stop
1292 replies. Without exit events, if one of the threads exits, GDB
1293 would hang forever not knowing that it should no longer expect a
1294 stop for that same thread.
1297 Indicates that there are no resumed threads left in the target (all
1298 threads are stopped). The remote stub reports support for this stop
1299 reply to GDB's qSupported query.
1302 Enables/disables catching syscalls from the inferior process.
1303 The remote stub reports support for this packet to GDB's qSupported query.
1305 syscall_entry stop reason
1306 Indicates that a syscall was just called.
1308 syscall_return stop reason
1309 Indicates that a syscall just returned.
1311 * Extended-remote exec events
1313 ** GDB now has support for exec events on extended-remote Linux targets.
1314 For such targets with Linux kernels 2.5.46 and later, this enables
1315 follow-exec-mode and exec catchpoints.
1317 set remote exec-event-feature-packet
1318 show remote exec-event-feature-packet
1319 Set/show the use of the remote exec event feature.
1321 * Thread names in remote protocol
1323 The reply to qXfer:threads:read may now include a name attribute for each
1326 * Target remote mode fork and exec events
1328 ** GDB now has support for fork and exec events on target remote mode
1329 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1330 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1331 fork and exec catchpoints.
1333 * Remote syscall events
1335 ** GDB now has support for catch syscall on remote Linux targets,
1336 currently enabled on x86/x86_64 architectures.
1338 set remote catch-syscall-packet
1339 show remote catch-syscall-packet
1340 Set/show the use of the remote catch syscall feature.
1344 ** The -var-set-format command now accepts the zero-hexadecimal
1345 format. It outputs data in hexadecimal format with zero-padding on the
1350 ** gdb.InferiorThread objects have a new attribute "global_num",
1351 which refers to the thread's global thread ID. The existing
1352 "num" attribute now refers to the thread's per-inferior number.
1353 See "Per-inferior thread numbers" above.
1354 ** gdb.InferiorThread objects have a new attribute "inferior", which
1355 is the Inferior object the thread belongs to.
1357 *** Changes in GDB 7.10
1359 * Support for process record-replay and reverse debugging on aarch64*-linux*
1360 targets has been added. GDB now supports recording of A64 instruction set
1361 including advance SIMD instructions.
1363 * Support for Sun's version of the "stabs" debug file format has been removed.
1365 * GDB now honors the content of the file /proc/PID/coredump_filter
1366 (PID is the process ID) on GNU/Linux systems. This file can be used
1367 to specify the types of memory mappings that will be included in a
1368 corefile. For more information, please refer to the manual page of
1369 "core(5)". GDB also has a new command: "set use-coredump-filter
1370 on|off". It allows to set whether GDB will read the content of the
1371 /proc/PID/coredump_filter file when generating a corefile.
1373 * The "info os" command on GNU/Linux can now display information on
1375 "info os cpus" Listing of all cpus/cores on the system
1377 * GDB has two new commands: "set serial parity odd|even|none" and
1378 "show serial parity". These allows to set or show parity for the
1381 * The "info source" command now displays the producer string if it was
1382 present in the debug info. This typically includes the compiler version
1383 and may include things like its command line arguments.
1385 * The "info dll", an alias of the "info sharedlibrary" command,
1386 is now available on all platforms.
1388 * Directory names supplied to the "set sysroot" commands may be
1389 prefixed with "target:" to tell GDB to access shared libraries from
1390 the target system, be it local or remote. This replaces the prefix
1391 "remote:". The default sysroot has been changed from "" to
1392 "target:". "remote:" is automatically converted to "target:" for
1393 backward compatibility.
1395 * The system root specified by "set sysroot" will be prepended to the
1396 filename of the main executable (if reported to GDB as absolute by
1397 the operating system) when starting processes remotely, and when
1398 attaching to already-running local or remote processes.
1400 * GDB now supports automatic location and retrieval of executable
1401 files from remote targets. Remote debugging can now be initiated
1402 using only a "target remote" or "target extended-remote" command
1403 (no "set sysroot" or "file" commands are required). See "New remote
1406 * The "dump" command now supports verilog hex format.
1408 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1410 * On GNU/Linux, GDB and gdbserver are now able to access executable
1411 and shared library files without a "set sysroot" command when
1412 attaching to processes running in different mount namespaces from
1413 the debugger. This makes it possible to attach to processes in
1414 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1415 See "New remote packets" below.
1417 * The "tui reg" command now provides completion for all of the
1418 available register groups, including target specific groups.
1420 * The HISTSIZE environment variable is no longer read when determining
1421 the size of GDB's command history. GDB now instead reads the dedicated
1422 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1423 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1428 ** Memory ports can now be unbuffered.
1432 ** gdb.Objfile objects have a new attribute "username",
1433 which is the name of the objfile as specified by the user,
1434 without, for example, resolving symlinks.
1435 ** You can now write frame unwinders in Python.
1436 ** gdb.Type objects have a new method "optimized_out",
1437 returning optimized out gdb.Value instance of this type.
1438 ** gdb.Value objects have new methods "reference_value" and
1439 "const_value" which return a reference to the value and a
1440 "const" version of the value respectively.
1444 maint print symbol-cache
1445 Print the contents of the symbol cache.
1447 maint print symbol-cache-statistics
1448 Print statistics of symbol cache usage.
1450 maint flush-symbol-cache
1451 Flush the contents of the symbol cache.
1455 Start branch trace recording using Branch Trace Store (BTS) format.
1458 Evaluate expression by using the compiler and print result.
1462 Explicit commands for enabling and disabling tui mode.
1465 set mpx bound on i386 and amd64
1466 Support for bound table investigation on Intel MPX enabled applications.
1470 Start branch trace recording using Intel Processor Trace format.
1473 Print information about branch tracing internals.
1475 maint btrace packet-history
1476 Print the raw branch tracing data.
1478 maint btrace clear-packet-history
1479 Discard the stored raw branch tracing data.
1482 Discard all branch tracing data. It will be fetched and processed
1483 anew by the next "record" command.
1488 Renamed from "set debug dwarf2-die".
1489 show debug dwarf-die
1490 Renamed from "show debug dwarf2-die".
1492 set debug dwarf-read
1493 Renamed from "set debug dwarf2-read".
1494 show debug dwarf-read
1495 Renamed from "show debug dwarf2-read".
1497 maint set dwarf always-disassemble
1498 Renamed from "maint set dwarf2 always-disassemble".
1499 maint show dwarf always-disassemble
1500 Renamed from "maint show dwarf2 always-disassemble".
1502 maint set dwarf max-cache-age
1503 Renamed from "maint set dwarf2 max-cache-age".
1504 maint show dwarf max-cache-age
1505 Renamed from "maint show dwarf2 max-cache-age".
1507 set debug dwarf-line
1508 show debug dwarf-line
1509 Control display of debugging info regarding DWARF line processing.
1512 show max-completions
1513 Set the maximum number of candidates to be considered during
1514 completion. The default value is 200. This limit allows GDB
1515 to avoid generating large completion lists, the computation of
1516 which can cause the debugger to become temporarily unresponsive.
1518 set history remove-duplicates
1519 show history remove-duplicates
1520 Control the removal of duplicate history entries.
1522 maint set symbol-cache-size
1523 maint show symbol-cache-size
1524 Control the size of the symbol cache.
1526 set|show record btrace bts buffer-size
1527 Set and show the size of the ring buffer used for branch tracing in
1529 The obtained size may differ from the requested size. Use "info
1530 record" to see the obtained buffer size.
1532 set debug linux-namespaces
1533 show debug linux-namespaces
1534 Control display of debugging info regarding Linux namespaces.
1536 set|show record btrace pt buffer-size
1537 Set and show the size of the ring buffer used for branch tracing in
1538 Intel Processor Trace format.
1539 The obtained size may differ from the requested size. Use "info
1540 record" to see the obtained buffer size.
1542 maint set|show btrace pt skip-pad
1543 Set and show whether PAD packets are skipped when computing the
1546 * The command 'thread apply all' can now support new option '-ascending'
1547 to call its specified command for all threads in ascending order.
1549 * Python/Guile scripting
1551 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1552 special section named `.debug_gdb_scripts'.
1554 * New remote packets
1556 qXfer:btrace-conf:read
1557 Return the branch trace configuration for the current thread.
1559 Qbtrace-conf:bts:size
1560 Set the requested ring buffer size for branch tracing in BTS format.
1563 Enable Intel Procesor Trace-based branch tracing for the current
1564 process. The remote stub reports support for this packet to GDB's
1567 Qbtrace-conf:pt:size
1568 Set the requested ring buffer size for branch tracing in Intel Processor
1572 Indicates a memory breakpoint instruction was executed, irrespective
1573 of whether it was GDB that planted the breakpoint or the breakpoint
1574 is hardcoded in the program. This is required for correct non-stop
1578 Indicates the target stopped for a hardware breakpoint. This is
1579 required for correct non-stop mode operation.
1582 Return information about files on the remote system.
1584 qXfer:exec-file:read
1585 Return the full absolute name of the file that was executed to
1586 create a process running on the remote system.
1589 Select the filesystem on which vFile: operations with filename
1590 arguments will operate. This is required for GDB to be able to
1591 access files on remote targets where the remote stub does not
1592 share a common filesystem with the inferior(s).
1595 Indicates that a fork system call was executed.
1598 Indicates that a vfork system call was executed.
1600 vforkdone stop reason
1601 Indicates that a vfork child of the specified process has executed
1602 an exec or exit, allowing the vfork parent to resume execution.
1604 fork-events and vfork-events features in qSupported
1605 The qSupported packet allows GDB to request support for fork and
1606 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1607 and the qSupported response can contain the corresponding
1608 'stubfeatures'. Set and show commands can be used to display
1609 whether these features are enabled.
1611 * Extended-remote fork events
1613 ** GDB now has support for fork events on extended-remote Linux
1614 targets. For targets with Linux kernels 2.5.60 and later, this
1615 enables follow-fork-mode and detach-on-fork for both fork and
1616 vfork, as well as fork and vfork catchpoints.
1618 * The info record command now shows the recording format and the
1619 branch tracing configuration for the current thread when using
1620 the btrace record target.
1621 For the BTS format, it shows the ring buffer size.
1623 * GDB now has support for DTrace USDT (Userland Static Defined
1624 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1626 * GDB now supports access to vector registers on S/390 GNU/Linux
1629 * Removed command line options
1631 -xdb HP-UX XDB compatibility mode.
1633 * Removed targets and native configurations
1635 HP/PA running HP-UX hppa*-*-hpux*
1636 Itanium running HP-UX ia64-*-hpux*
1638 * New configure options
1641 This configure option allows the user to build GDB with support for
1642 Intel Processor Trace (default: auto). This requires libipt.
1644 --with-libipt-prefix=PATH
1645 Specify the path to the version of libipt that GDB should use.
1646 $PATH/include should contain the intel-pt.h header and
1647 $PATH/lib should contain the libipt.so library.
1649 *** Changes in GDB 7.9.1
1653 ** Xmethods can now specify a result type.
1655 *** Changes in GDB 7.9
1657 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1661 ** You can now access frame registers from Python scripts.
1662 ** New attribute 'producer' for gdb.Symtab objects.
1663 ** gdb.Objfile objects have a new attribute "progspace",
1664 which is the gdb.Progspace object of the containing program space.
1665 ** gdb.Objfile objects have a new attribute "owner".
1666 ** gdb.Objfile objects have a new attribute "build_id",
1667 which is the build ID generated when the file was built.
1668 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1669 ** A new event "gdb.clear_objfiles" has been added, triggered when
1670 selecting a new file to debug.
1671 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1672 ** New function gdb.lookup_objfile.
1674 New events which are triggered when GDB modifies the state of the
1677 ** gdb.events.inferior_call_pre: Function call is about to be made.
1678 ** gdb.events.inferior_call_post: Function call has just been made.
1679 ** gdb.events.memory_changed: A memory location has been altered.
1680 ** gdb.events.register_changed: A register has been altered.
1682 * New Python-based convenience functions:
1684 ** $_caller_is(name [, number_of_frames])
1685 ** $_caller_matches(regexp [, number_of_frames])
1686 ** $_any_caller_is(name [, number_of_frames])
1687 ** $_any_caller_matches(regexp [, number_of_frames])
1689 * GDB now supports the compilation and injection of source code into
1690 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1691 to compile the source code to object code, and if successful, inject
1692 and execute that code within the current context of the inferior.
1693 Currently the C language is supported. The commands used to
1694 interface with this new feature are:
1696 compile code [-raw|-r] [--] [source code]
1697 compile file [-raw|-r] filename
1701 demangle [-l language] [--] name
1702 Demangle "name" in the specified language, or the current language
1703 if elided. This command is renamed from the "maint demangle" command.
1704 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1705 as "maint demangler-warning".
1707 queue-signal signal-name-or-number
1708 Queue a signal to be delivered to the thread when it is resumed.
1710 add-auto-load-scripts-directory directory
1711 Add entries to the list of directories from which to load auto-loaded
1714 maint print user-registers
1715 List all currently available "user" registers.
1717 compile code [-r|-raw] [--] [source code]
1718 Compile, inject, and execute in the inferior the executable object
1719 code produced by compiling the provided source code.
1721 compile file [-r|-raw] filename
1722 Compile and inject into the inferior the executable object code
1723 produced by compiling the source code stored in the filename
1726 * On resume, GDB now always passes the signal the program had stopped
1727 for to the thread the signal was sent to, even if the user changed
1728 threads before resuming. Previously GDB would often (but not
1729 always) deliver the signal to the thread that happens to be current
1732 * Conversely, the "signal" command now consistently delivers the
1733 requested signal to the current thread. GDB now asks for
1734 confirmation if the program had stopped for a signal and the user
1735 switched threads meanwhile.
1737 * "breakpoint always-inserted" modes "off" and "auto" merged.
1739 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1740 won't remove breakpoints from the target until all threads stop,
1741 even in non-stop mode. The "auto" mode has been removed, and "off"
1742 is now the default mode.
1746 set debug symbol-lookup
1747 show debug symbol-lookup
1748 Control display of debugging info regarding symbol lookup.
1752 ** The -list-thread-groups command outputs an exit-code field for
1753 inferiors that have exited.
1757 MIPS SDE mips*-sde*-elf*
1761 Support for these obsolete configurations has been removed.
1763 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1764 SGI Irix-5.x mips-*-irix5*
1765 SGI Irix-6.x mips-*-irix6*
1766 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1767 VAX running Ultrix vax-*-ultrix*
1769 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1770 and "assf"), have been removed. Use the "sharedlibrary" command, or
1771 its alias "share", instead.
1773 *** Changes in GDB 7.8
1775 * New command line options
1778 This is an alias for the --data-directory option.
1780 * GDB supports printing and modifying of variable length automatic arrays
1781 as specified in ISO C99.
1783 * The ARM simulator now supports instruction level tracing
1784 with or without disassembly.
1788 GDB now has support for scripting using Guile. Whether this is
1789 available is determined at configure time.
1790 Guile version 2.0 or greater is required.
1791 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1793 * New commands (for set/show, see "New options" below)
1797 Invoke CODE by passing it to the Guile interpreter.
1801 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1803 info auto-load guile-scripts [regexp]
1804 Print the list of automatically loaded Guile scripts.
1806 * The source command is now capable of sourcing Guile scripts.
1807 This feature is dependent on the debugger being built with Guile support.
1811 set print symbol-loading (off|brief|full)
1812 show print symbol-loading
1813 Control whether to print informational messages when loading symbol
1814 information for a file. The default is "full", but when debugging
1815 programs with large numbers of shared libraries the amount of output
1816 becomes less useful.
1818 set guile print-stack (none|message|full)
1819 show guile print-stack
1820 Show a stack trace when an error is encountered in a Guile script.
1822 set auto-load guile-scripts (on|off)
1823 show auto-load guile-scripts
1824 Control auto-loading of Guile script files.
1826 maint ada set ignore-descriptive-types (on|off)
1827 maint ada show ignore-descriptive-types
1828 Control whether the debugger should ignore descriptive types in Ada
1829 programs. The default is not to ignore the descriptive types. See
1830 the user manual for more details on descriptive types and the intended
1831 usage of this option.
1833 set auto-connect-native-target
1835 Control whether GDB is allowed to automatically connect to the
1836 native target for the run, attach, etc. commands when not connected
1837 to any target yet. See also "target native" below.
1839 set record btrace replay-memory-access (read-only|read-write)
1840 show record btrace replay-memory-access
1841 Control what memory accesses are allowed during replay.
1843 maint set target-async (on|off)
1844 maint show target-async
1845 This controls whether GDB targets operate in synchronous or
1846 asynchronous mode. Normally the default is asynchronous, if it is
1847 available; but this can be changed to more easily debug problems
1848 occurring only in synchronous mode.
1850 set mi-async (on|off)
1852 Control whether MI asynchronous mode is preferred. This supersedes
1853 "set target-async" of previous GDB versions.
1855 * "set target-async" is deprecated as a CLI option and is now an alias
1856 for "set mi-async" (only puts MI into async mode).
1858 * Background execution commands (e.g., "c&", "s&", etc.) are now
1859 possible ``out of the box'' if the target supports them. Previously
1860 the user would need to explicitly enable the possibility with the
1861 "set target-async on" command.
1863 * New features in the GDB remote stub, GDBserver
1865 ** New option --debug-format=option1[,option2,...] allows one to add
1866 additional text to each output. At present only timestamps
1867 are supported: --debug-format=timestamps.
1868 Timestamps can also be turned on with the
1869 "monitor set debug-format timestamps" command from GDB.
1871 * The 'record instruction-history' command now starts counting instructions
1872 at one. This also affects the instruction ranges reported by the
1873 'record function-call-history' command when given the /i modifier.
1875 * The command 'record function-call-history' supports a new modifier '/c' to
1876 indent the function names based on their call stack depth.
1877 The fields for the '/i' and '/l' modifier have been reordered.
1878 The source line range is now prefixed with 'at'.
1879 The instruction range is now prefixed with 'inst'.
1880 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1881 "record instruction-history" and "list" commands.
1883 * The ranges given as arguments to the 'record function-call-history' and
1884 'record instruction-history' commands are now inclusive.
1886 * The btrace record target now supports the 'record goto' command.
1887 For locations inside the execution trace, the back trace is computed
1888 based on the information stored in the execution trace.
1890 * The btrace record target supports limited reverse execution and replay.
1891 The target does not record data and therefore does not allow reading
1892 memory or registers.
1894 * The "catch syscall" command now works on s390*-linux* targets.
1896 * The "compare-sections" command is no longer specific to target
1897 remote. It now works with all targets.
1899 * All native targets are now consistently called "native".
1900 Consequently, the "target child", "target GNU", "target djgpp",
1901 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1902 commands have been replaced with "target native". The QNX/NTO port
1903 leaves the "procfs" target in place and adds a "native" target for
1904 consistency with other ports. The impact on users should be minimal
1905 as these commands previously either throwed an error, or were
1906 no-ops. The target's name is visible in the output of the following
1907 commands: "help target", "info target", "info files", "maint print
1910 * The "target native" command now connects to the native target. This
1911 can be used to launch native programs even when "set
1912 auto-connect-native-target" is set to off.
1914 * GDB now supports access to Intel MPX registers on GNU/Linux.
1916 * Support for Intel AVX-512 registers on GNU/Linux.
1917 Support displaying and modifying Intel AVX-512 registers
1918 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1920 * New remote packets
1922 qXfer:btrace:read's annex
1923 The qXfer:btrace:read packet supports a new annex 'delta' to read
1924 branch trace incrementally.
1928 ** Valid Python operations on gdb.Value objects representing
1929 structs/classes invoke the corresponding overloaded operators if
1931 ** New `Xmethods' feature in the Python API. Xmethods are
1932 additional methods or replacements for existing methods of a C++
1933 class. This feature is useful for those cases where a method
1934 defined in C++ source code could be inlined or optimized out by
1935 the compiler, making it unavailable to GDB.
1938 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1940 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1941 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1942 its alias "share", instead.
1944 * The commands "set remotebaud" and "show remotebaud" are no longer
1945 supported. Use "set serial baud" and "show serial baud" (respectively)
1950 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1951 target-async". The latter is left as a deprecated alias of the
1952 former for backward compatibility. If the target supports it,
1953 CLI background execution commands are now always possible by
1954 default, independently of whether the frontend stated a
1955 preference for asynchronous execution with "-gdb-set mi-async".
1956 Previously "-gdb-set target-async off" affected both MI execution
1957 commands and CLI execution commands.
1959 *** Changes in GDB 7.7
1961 * Improved support for process record-replay and reverse debugging on
1962 arm*-linux* targets. Support for thumb32 and syscall instruction
1963 recording has been added.
1965 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1967 * GDB now supports Fission DWP file format version 2.
1968 http://gcc.gnu.org/wiki/DebugFission
1970 * New convenience function "$_isvoid", to check whether an expression
1971 is void. A void expression is an expression where the type of the
1972 result is "void". For example, some convenience variables may be
1973 "void" when evaluated (e.g., "$_exitcode" before the execution of
1974 the program being debugged; or an undefined convenience variable).
1975 Another example, when calling a function whose return type is
1978 * The "maintenance print objfiles" command now takes an optional regexp.
1980 * The "catch syscall" command now works on arm*-linux* targets.
1982 * GDB now consistently shows "<not saved>" when printing values of
1983 registers the debug info indicates have not been saved in the frame
1984 and there's nowhere to retrieve them from
1985 (callee-saved/call-clobbered registers):
1990 (gdb) info registers rax
1993 Before, the former would print "<optimized out>", and the latter
1994 "*value not available*".
1996 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2001 ** Frame filters and frame decorators have been added.
2002 ** Temporary breakpoints are now supported.
2003 ** Line tables representation has been added.
2004 ** New attribute 'parent_type' for gdb.Field objects.
2005 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2006 ** New attribute 'name' for gdb.Type objects.
2010 Nios II ELF nios2*-*-elf
2011 Nios II GNU/Linux nios2*-*-linux
2012 Texas Instruments MSP430 msp430*-*-elf
2014 * Removed native configurations
2016 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2017 been removed. ELF variants of these configurations are kept supported.
2019 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2020 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2021 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2022 i[34567]86-*-openbsd3.[0-3]
2023 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2024 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2025 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2029 Like "catch throw", but catches a re-thrown exception.
2030 maint check-psymtabs
2031 Renamed from old "maint check-symtabs".
2033 Perform consistency checks on symtabs.
2034 maint expand-symtabs
2035 Expand symtabs matching an optional regexp.
2038 Display the details of GDB configure-time options.
2040 maint set|show per-command
2041 maint set|show per-command space
2042 maint set|show per-command time
2043 maint set|show per-command symtab
2044 Enable display of per-command gdb resource usage.
2046 remove-symbol-file FILENAME
2047 remove-symbol-file -a ADDRESS
2048 Remove a symbol file added via add-symbol-file. The file to remove
2049 can be identified by its filename or by an address that lies within
2050 the boundaries of this symbol file in memory.
2053 info exceptions REGEXP
2054 Display the list of Ada exceptions defined in the program being
2055 debugged. If provided, only the exceptions whose names match REGEXP
2060 set debug symfile off|on
2062 Control display of debugging info regarding reading symbol files and
2063 symbol tables within those files
2065 set print raw frame-arguments
2066 show print raw frame-arguments
2067 Set/show whether to print frame arguments in raw mode,
2068 disregarding any defined pretty-printers.
2070 set remote trace-status-packet
2071 show remote trace-status-packet
2072 Set/show the use of remote protocol qTStatus packet.
2076 Control display of debugging messages related to Nios II targets.
2080 Control whether target-assisted range stepping is enabled.
2082 set startup-with-shell
2083 show startup-with-shell
2084 Specifies whether Unix child processes are started via a shell or
2089 Use the target memory cache for accesses to the code segment. This
2090 improves performance of remote debugging (particularly disassembly).
2092 * You can now use a literal value 'unlimited' for options that
2093 interpret 0 or -1 as meaning "unlimited". E.g., "set
2094 trace-buffer-size unlimited" is now an alias for "set
2095 trace-buffer-size -1" and "set height unlimited" is now an alias for
2098 * The "set debug symtab-create" debugging option of GDB has been changed to
2099 accept a verbosity level. 0 means "off", 1 provides basic debugging
2100 output, and values of 2 or greater provides more verbose output.
2102 * New command-line options
2104 Display the details of GDB configure-time options.
2106 * The command 'tsave' can now support new option '-ctf' to save trace
2107 buffer in Common Trace Format.
2109 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2112 * GDB now implements the the C++ 'typeid' operator.
2114 * The new convenience variable $_exception holds the exception being
2115 thrown or caught at an exception-related catchpoint.
2117 * The exception-related catchpoints, like "catch throw", now accept a
2118 regular expression which can be used to filter exceptions by type.
2120 * The new convenience variable $_exitsignal is automatically set to
2121 the terminating signal number when the program being debugged dies
2122 due to an uncaught signal.
2126 ** All MI commands now accept an optional "--language" option.
2127 Support for this feature can be verified by using the "-list-features"
2128 command, which should contain "language-option".
2130 ** The new command -info-gdb-mi-command allows the user to determine
2131 whether a GDB/MI command is supported or not.
2133 ** The "^error" result record returned when trying to execute an undefined
2134 GDB/MI command now provides a variable named "code" whose content is the
2135 "undefined-command" error code. Support for this feature can be verified
2136 by using the "-list-features" command, which should contain
2137 "undefined-command-error-code".
2139 ** The -trace-save MI command can optionally save trace buffer in Common
2142 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2144 ** The command -data-list-register-values now accepts an optional
2145 "--skip-unavailable" option. When used, only the available registers
2148 ** The new command -trace-frame-collected dumps collected variables,
2149 computed expressions, tvars, memory and registers in a traceframe.
2151 ** The commands -stack-list-locals, -stack-list-arguments and
2152 -stack-list-variables now accept an option "--skip-unavailable".
2153 When used, only the available locals or arguments are displayed.
2155 ** The -exec-run command now accepts an optional "--start" option.
2156 When used, the command follows the same semantics as the "start"
2157 command, stopping the program's execution at the start of its
2158 main subprogram. Support for this feature can be verified using
2159 the "-list-features" command, which should contain
2160 "exec-run-start-option".
2162 ** The new commands -catch-assert and -catch-exceptions insert
2163 catchpoints stopping the program when Ada exceptions are raised.
2165 ** The new command -info-ada-exceptions provides the equivalent of
2166 the new "info exceptions" command.
2168 * New system-wide configuration scripts
2169 A GDB installation now provides scripts suitable for use as system-wide
2170 configuration scripts for the following systems:
2174 * GDB now supports target-assigned range stepping with remote targets.
2175 This improves the performance of stepping source lines by reducing
2176 the number of control packets from/to GDB. See "New remote packets"
2179 * GDB now understands the element 'tvar' in the XML traceframe info.
2180 It has the id of the collected trace state variables.
2182 * On S/390 targets that provide the transactional-execution feature,
2183 the program interruption transaction diagnostic block (TDB) is now
2184 represented as a number of additional "registers" in GDB.
2186 * New remote packets
2190 The vCont packet supports a new 'r' action, that tells the remote
2191 stub to step through an address range itself, without GDB
2192 involvemement at each single-step.
2194 qXfer:libraries-svr4:read's annex
2195 The previously unused annex of the qXfer:libraries-svr4:read packet
2196 is now used to support passing an argument list. The remote stub
2197 reports support for this argument list to GDB's qSupported query.
2198 The defined arguments are "start" and "prev", used to reduce work
2199 necessary for library list updating, resulting in significant
2202 * New features in the GDB remote stub, GDBserver
2204 ** GDBserver now supports target-assisted range stepping. Currently
2205 enabled on x86/x86_64 GNU/Linux targets.
2207 ** GDBserver now adds element 'tvar' in the XML in the reply to
2208 'qXfer:traceframe-info:read'. It has the id of the collected
2209 trace state variables.
2211 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2214 * New 'z' formatter for printing and examining memory, this displays the
2215 value as hexadecimal zero padded on the left to the size of the type.
2217 * GDB can now use Windows x64 unwinding data.
2219 * The "set remotebaud" command has been replaced by "set serial baud".
2220 Similarly, "show remotebaud" has been replaced by "show serial baud".
2221 The "set remotebaud" and "show remotebaud" commands are still available
2222 to provide backward compatibility with older versions of GDB.
2224 *** Changes in GDB 7.6
2226 * Target record has been renamed to record-full.
2227 Record/replay is now enabled with the "record full" command.
2228 This also affects settings that are associated with full record/replay
2229 that have been moved from "set/show record" to "set/show record full":
2231 set|show record full insn-number-max
2232 set|show record full stop-at-limit
2233 set|show record full memory-query
2235 * A new record target "record-btrace" has been added. The new target
2236 uses hardware support to record the control-flow of a process. It
2237 does not support replaying the execution, but it implements the
2238 below new commands for investigating the recorded execution log.
2239 This new recording method can be enabled using:
2243 The "record-btrace" target is only available on Intel Atom processors
2244 and requires a Linux kernel 2.6.32 or later.
2246 * Two new commands have been added for record/replay to give information
2247 about the recorded execution without having to replay the execution.
2248 The commands are only supported by "record btrace".
2250 record instruction-history prints the execution history at
2251 instruction granularity
2253 record function-call-history prints the execution history at
2254 function granularity
2256 * New native configurations
2258 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2259 FreeBSD/powerpc powerpc*-*-freebsd
2260 x86_64/Cygwin x86_64-*-cygwin*
2261 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2265 ARM AArch64 aarch64*-*-elf
2266 ARM AArch64 GNU/Linux aarch64*-*-linux
2267 Lynx 178 PowerPC powerpc-*-lynx*178
2268 x86_64/Cygwin x86_64-*-cygwin*
2269 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2271 * If the configured location of system.gdbinit file (as given by the
2272 --with-system-gdbinit option at configure time) is in the
2273 data-directory (as specified by --with-gdb-datadir at configure
2274 time) or in one of its subdirectories, then GDB will look for the
2275 system-wide init file in the directory specified by the
2276 --data-directory command-line option.
2278 * New command line options:
2280 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2281 other initialization files, unlike -nx which disables all of them.
2283 * Removed command line options
2285 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2288 * The 'ptype' and 'whatis' commands now accept an argument to control
2291 * 'info proc' now works on some core files.
2295 ** Vectors can be created with gdb.Type.vector.
2297 ** Python's atexit.register now works in GDB.
2299 ** Types can be pretty-printed via a Python API.
2301 ** Python 3 is now supported (in addition to Python 2.4 or later)
2303 ** New class gdb.Architecture exposes GDB's internal representation
2304 of architecture in the Python API.
2306 ** New method Frame.architecture returns the gdb.Architecture object
2307 corresponding to the frame's architecture.
2309 * New Python-based convenience functions:
2311 ** $_memeq(buf1, buf2, length)
2312 ** $_streq(str1, str2)
2314 ** $_regex(str, regex)
2316 * The 'cd' command now defaults to using '~' (the home directory) if not
2319 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2320 default for GCC since November 2000.
2322 * The command 'forward-search' can now be abbreviated as 'fo'.
2324 * The command 'info tracepoints' can now display 'installed on target'
2325 or 'not installed on target' for each non-pending location of tracepoint.
2327 * New configure options
2329 --enable-libmcheck/--disable-libmcheck
2330 By default, development versions are built with -lmcheck on hosts
2331 that support it, in order to help track memory corruption issues.
2332 Release versions, on the other hand, are built without -lmcheck
2333 by default. The --enable-libmcheck/--disable-libmcheck configure
2334 options allow the user to override that default.
2335 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2336 This configure option allows the user to build GDB with
2337 libbabeltrace using which GDB can read Common Trace Format data.
2339 * New commands (for set/show, see "New options" below)
2342 Catch signals. This is similar to "handle", but allows commands and
2343 conditions to be attached.
2346 List the BFDs known to GDB.
2348 python-interactive [command]
2350 Start a Python interactive prompt, or evaluate the optional command
2351 and print the result of expressions.
2354 "py" is a new alias for "python".
2356 enable type-printer [name]...
2357 disable type-printer [name]...
2358 Enable or disable type printers.
2362 ** For the Renesas Super-H architecture, the "regs" command has been removed
2363 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2368 set print type methods (on|off)
2369 show print type methods
2370 Control whether method declarations are displayed by "ptype".
2371 The default is to show them.
2373 set print type typedefs (on|off)
2374 show print type typedefs
2375 Control whether typedef definitions are displayed by "ptype".
2376 The default is to show them.
2378 set filename-display basename|relative|absolute
2379 show filename-display
2380 Control the way in which filenames is displayed.
2381 The default is "relative", which preserves previous behavior.
2383 set trace-buffer-size
2384 show trace-buffer-size
2385 Request target to change the size of trace buffer.
2387 set remote trace-buffer-size-packet auto|on|off
2388 show remote trace-buffer-size-packet
2389 Control the use of the remote protocol `QTBuffer:size' packet.
2393 Control display of debugging messages related to ARM AArch64.
2396 set debug coff-pe-read
2397 show debug coff-pe-read
2398 Control display of debugging messages related to reading of COFF/PE
2403 Control display of debugging messages related to Mach-O symbols
2406 set debug notification
2407 show debug notification
2408 Control display of debugging info for async remote notification.
2412 ** Command parameter changes are now notified using new async record
2413 "=cmd-param-changed".
2414 ** Trace frame changes caused by command "tfind" are now notified using
2415 new async record "=traceframe-changed".
2416 ** The creation, deletion and modification of trace state variables
2417 are now notified using new async records "=tsv-created",
2418 "=tsv-deleted" and "=tsv-modified".
2419 ** The start and stop of process record are now notified using new
2420 async record "=record-started" and "=record-stopped".
2421 ** Memory changes are now notified using new async record
2423 ** The data-disassemble command response will include a "fullname" field
2424 containing the absolute file name when source has been requested.
2425 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2426 command, to allow pattern filling of memory areas.
2427 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2428 library load/unload events.
2429 ** The response to breakpoint commands and breakpoint async records
2430 includes an "installed" field containing a boolean state about each
2431 non-pending tracepoint location is whether installed on target or not.
2432 ** Output of the "-trace-status" command includes a "trace-file" field
2433 containing the name of the trace file being examined. This field is
2434 optional, and only present when examining a trace file.
2435 ** The "fullname" field is now always present along with the "file" field,
2436 even if the file cannot be found by GDB.
2438 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2439 You must have the LZMA library available when configuring GDB for this
2440 feature to be enabled. For more information, see:
2441 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2443 * New remote packets
2446 Set the size of trace buffer. The remote stub reports support for this
2447 packet to gdb's qSupported query.
2450 Enable Branch Trace Store (BTS)-based branch tracing for the current
2451 thread. The remote stub reports support for this packet to gdb's
2455 Disable branch tracing for the current thread. The remote stub reports
2456 support for this packet to gdb's qSupported query.
2459 Read the traced branches for the current thread. The remote stub
2460 reports support for this packet to gdb's qSupported query.
2462 *** Changes in GDB 7.5
2464 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2465 for more x32 ABI info.
2467 * GDB now supports access to MIPS DSP registers on Linux targets.
2469 * GDB now supports debugging microMIPS binaries.
2471 * The "info os" command on GNU/Linux can now display information on
2472 several new classes of objects managed by the operating system:
2473 "info os procgroups" lists process groups
2474 "info os files" lists file descriptors
2475 "info os sockets" lists internet-domain sockets
2476 "info os shm" lists shared-memory regions
2477 "info os semaphores" lists semaphores
2478 "info os msg" lists message queues
2479 "info os modules" lists loaded kernel modules
2481 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2482 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2483 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2484 options and inspect the probe arguments using the new $_probe_arg family
2485 of convenience variables. You can obtain more information about SystemTap
2486 in <http://sourceware.org/systemtap/>.
2488 * GDB now supports reversible debugging on ARM, it allows you to
2489 debug basic ARM and THUMB instructions, and provides
2490 record/replay support.
2492 * The option "symbol-reloading" has been deleted as it is no longer used.
2496 ** GDB commands implemented in Python can now be put in command class
2499 ** The "maint set python print-stack on|off" is now deleted.
2501 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2502 apply "flag enum"-style pretty-printing to any enum.
2504 ** gdb.lookup_symbol can now work when there is no current frame.
2506 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2507 the source at which the symbol was defined.
2509 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2510 method 'value'. The former indicates whether the symbol needs a
2511 frame in order to compute its value, and the latter computes the
2514 ** A new method 'referenced_value' on gdb.Value objects which can
2515 dereference pointer as well as C++ reference values.
2517 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2518 which return the global and static blocks (as gdb.Block objects),
2519 of the underlying symbol table, respectively.
2521 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2522 object associated with a PC value.
2524 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2525 of the address range occupied by code for the current source line.
2527 * Go language support.
2528 GDB now supports debugging programs written in the Go programming
2531 * GDBserver now supports stdio connections.
2532 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2534 * The binary "gdbtui" can no longer be built or installed.
2535 Use "gdb -tui" instead.
2537 * GDB will now print "flag" enums specially. A flag enum is one where
2538 all the enumerator values have no bits in common when pairwise
2539 "and"ed. When printing a value whose type is a flag enum, GDB will
2540 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2541 (gdb) print (enum E) 3
2544 * The filename part of a linespec will now match trailing components
2545 of a source file name. For example, "break gcc/expr.c:1000" will
2546 now set a breakpoint in build/gcc/expr.c, but not
2547 build/libcpp/expr.c.
2549 * The "info proc" and "generate-core-file" commands will now also
2550 work on remote targets connected to GDBserver on Linux.
2552 * The command "info catch" has been removed. It has been disabled
2553 since December 2007.
2555 * The "catch exception" and "catch assert" commands now accept
2556 a condition at the end of the command, much like the "break"
2557 command does. For instance:
2559 (gdb) catch exception Constraint_Error if Barrier = True
2561 Previously, it was possible to add a condition to such catchpoints,
2562 but it had to be done as a second step, after the catchpoint had been
2563 created, using the "condition" command.
2565 * The "info static-tracepoint-marker" command will now also work on
2566 native Linux targets with in-process agent.
2568 * GDB can now set breakpoints on inlined functions.
2570 * The .gdb_index section has been updated to include symbols for
2571 inlined functions. GDB will ignore older .gdb_index sections by
2572 default, which could cause symbol files to be loaded more slowly
2573 until their .gdb_index sections can be recreated. The new command
2574 "set use-deprecated-index-sections on" will cause GDB to use any older
2575 .gdb_index sections it finds. This will restore performance, but the
2576 ability to set breakpoints on inlined functions will be lost in symbol
2577 files with older .gdb_index sections.
2579 The .gdb_index section has also been updated to record more information
2580 about each symbol. This speeds up the "info variables", "info functions"
2581 and "info types" commands when used with programs having the .gdb_index
2582 section, as well as speeding up debugging with shared libraries using
2583 the .gdb_index section.
2585 * Ada support for GDB/MI Variable Objects has been added.
2587 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2592 ** New command -info-os is the MI equivalent of "info os".
2594 ** Output logs ("set logging" and related) now include MI output.
2598 ** "set use-deprecated-index-sections on|off"
2599 "show use-deprecated-index-sections on|off"
2600 Controls the use of deprecated .gdb_index sections.
2602 ** "catch load" and "catch unload" can be used to stop when a shared
2603 library is loaded or unloaded, respectively.
2605 ** "enable count" can be used to auto-disable a breakpoint after
2608 ** "info vtbl" can be used to show the virtual method tables for
2609 C++ and Java objects.
2611 ** "explore" and its sub commands "explore value" and "explore type"
2612 can be used to recursively explore values and types of
2613 expressions. These commands are available only if GDB is
2614 configured with '--with-python'.
2616 ** "info auto-load" shows status of all kinds of auto-loaded files,
2617 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2618 sequences of commands files, "info auto-load python-scripts"
2619 shows status of auto-loading Python script files,
2620 "info auto-load local-gdbinit" shows status of loading init file
2621 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2622 status of inferior specific thread debugging shared library loading.
2624 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2625 and "show auto-load-scripts" commands have been deprecated, use their
2626 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2627 and "show auto-load python-scripts" counterparts instead.
2629 ** "dprintf location,format,args..." creates a dynamic printf, which
2630 is basically a breakpoint that does a printf and immediately
2631 resumes your program's execution, so it is like a printf that you
2632 can insert dynamically at runtime instead of at compiletime.
2634 ** "set print symbol"
2636 Controls whether GDB attempts to display the symbol, if any,
2637 corresponding to addresses it prints. This defaults to "on", but
2638 you can set it to "off" to restore GDB's previous behavior.
2640 * Deprecated commands
2642 ** For the Renesas Super-H architecture, the "regs" command has been
2643 deprecated, and "info all-registers" should be used instead.
2647 Renesas RL78 rl78-*-elf
2648 HP OpenVMS ia64 ia64-hp-openvms*
2650 * GDBserver supports evaluation of breakpoint conditions. When
2651 support is advertised by GDBserver, GDB may be told to send the
2652 breakpoint conditions in bytecode form to GDBserver. GDBserver
2653 will only report the breakpoint trigger to GDB when its condition
2658 set mips compression
2659 show mips compression
2660 Select the compressed ISA encoding used in functions that have no symbol
2661 information available. The encoding can be set to either of:
2664 and is updated automatically from ELF file flags if available.
2666 set breakpoint condition-evaluation
2667 show breakpoint condition-evaluation
2668 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2669 GDBserver ("target"). Default option "auto" chooses the most efficient
2671 This option can improve debugger efficiency depending on the speed of the
2675 Disable auto-loading globally.
2678 Show auto-loading setting of all kinds of auto-loaded files.
2680 set auto-load gdb-scripts on|off
2681 show auto-load gdb-scripts
2682 Control auto-loading of GDB canned sequences of commands files.
2684 set auto-load python-scripts on|off
2685 show auto-load python-scripts
2686 Control auto-loading of Python script files.
2688 set auto-load local-gdbinit on|off
2689 show auto-load local-gdbinit
2690 Control loading of init file (.gdbinit) from current directory.
2692 set auto-load libthread-db on|off
2693 show auto-load libthread-db
2694 Control auto-loading of inferior specific thread debugging shared library.
2696 set auto-load scripts-directory <dir1>[:<dir2>...]
2697 show auto-load scripts-directory
2698 Set a list of directories from which to load auto-loaded scripts.
2699 Automatically loaded Python scripts and GDB scripts are located in one
2700 of the directories listed by this option.
2701 The delimiter (':' above) may differ according to the host platform.
2703 set auto-load safe-path <dir1>[:<dir2>...]
2704 show auto-load safe-path
2705 Set a list of directories from which it is safe to auto-load files.
2706 The delimiter (':' above) may differ according to the host platform.
2708 set debug auto-load on|off
2709 show debug auto-load
2710 Control display of debugging info for auto-loading the files above.
2712 set dprintf-style gdb|call|agent
2714 Control the way in which a dynamic printf is performed; "gdb"
2715 requests a GDB printf command, while "call" causes dprintf to call a
2716 function in the inferior. "agent" requests that the target agent
2717 (such as GDBserver) do the printing.
2719 set dprintf-function <expr>
2720 show dprintf-function
2721 set dprintf-channel <expr>
2722 show dprintf-channel
2723 Set the function and optional first argument to the call when using
2724 the "call" style of dynamic printf.
2726 set disconnected-dprintf on|off
2727 show disconnected-dprintf
2728 Control whether agent-style dynamic printfs continue to be in effect
2729 after GDB disconnects.
2731 * New configure options
2733 --with-auto-load-dir
2734 Configure default value for the 'set auto-load scripts-directory'
2735 setting above. It defaults to '$debugdir:$datadir/auto-load',
2736 $debugdir representing global debugging info directories (available
2737 via 'show debug-file-directory') and $datadir representing GDB's data
2738 directory (available via 'show data-directory').
2740 --with-auto-load-safe-path
2741 Configure default value for the 'set auto-load safe-path' setting
2742 above. It defaults to the --with-auto-load-dir setting.
2744 --without-auto-load-safe-path
2745 Set 'set auto-load safe-path' to '/', effectively disabling this
2748 * New remote packets
2750 z0/z1 conditional breakpoints extension
2752 The z0/z1 breakpoint insertion packets have been extended to carry
2753 a list of conditional expressions over to the remote stub depending on the
2754 condition evaluation mode. The use of this extension can be controlled
2755 via the "set remote conditional-breakpoints-packet" command.
2759 Specify the signals which the remote stub may pass to the debugged
2760 program without GDB involvement.
2762 * New command line options
2764 --init-command=FILE, -ix Like --command, -x but execute it
2765 before loading inferior.
2766 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2767 execute it before loading inferior.
2769 *** Changes in GDB 7.4
2771 * GDB now handles ambiguous linespecs more consistently; the existing
2772 FILE:LINE support has been expanded to other types of linespecs. A
2773 breakpoint will now be set on all matching locations in all
2774 inferiors, and locations will be added or removed according to
2777 * GDB now allows you to skip uninteresting functions and files when
2778 stepping with the "skip function" and "skip file" commands.
2780 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2781 and "show remote hardware-watchpoint-length-limit". These allows to
2782 set or show the maximum length limit (in bytes) of a remote
2783 target hardware watchpoint.
2785 This allows e.g. to use "unlimited" hardware watchpoints with the
2786 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2787 watchpoints are slower than real hardware watchpoints but are
2788 significantly faster than gdb software watchpoints.
2792 ** The register_pretty_printer function in module gdb.printing now takes
2793 an optional `replace' argument. If True, the new printer replaces any
2796 ** The "maint set python print-stack on|off" command has been
2797 deprecated and will be deleted in GDB 7.5.
2798 A new command: "set python print-stack none|full|message" has
2799 replaced it. Additionally, the default for "print-stack" is
2800 now "message", which just prints the error message without
2803 ** A prompt substitution hook (prompt_hook) is now available to the
2806 ** A new Python module, gdb.prompt has been added to the GDB Python
2807 modules library. This module provides functionality for
2808 escape sequences in prompts (used by set/show
2809 extended-prompt). These escape sequences are replaced by their
2810 corresponding value.
2812 ** Python commands and convenience-functions located in
2813 'data-directory'/python/gdb/command and
2814 'data-directory'/python/gdb/function are now automatically loaded
2817 ** Blocks now provide four new attributes. global_block and
2818 static_block will return the global and static blocks
2819 respectively. is_static and is_global are boolean attributes
2820 that indicate if the block is one of those two types.
2822 ** Symbols now provide the "type" attribute, the type of the symbol.
2824 ** The "gdb.breakpoint" function has been deprecated in favor of
2827 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2828 of a function. This class is based on the "finish" command
2829 available in the CLI.
2831 ** Type objects for struct and union types now allow access to
2832 the fields using standard Python dictionary (mapping) methods.
2833 For example, "some_type['myfield']" now works, as does
2834 "some_type.items()".
2836 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2839 ** A new function, "deep_items" has been added to the gdb.types
2840 module in the GDB Python modules library. This function returns
2841 an iterator over the fields of a struct or union type. Unlike
2842 the standard Python "iteritems" method, it will recursively traverse
2843 any anonymous fields.
2847 ** "*stopped" events can report several new "reason"s, such as
2850 ** Breakpoint changes are now notified using new async records, like
2851 "=breakpoint-modified".
2853 ** New command -ada-task-info.
2855 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2856 $sdir specifies the default system locations of shared libraries.
2857 $pdir specifies the directory where the libpthread used by the application
2860 GDB no longer looks in $sdir and $pdir after it has searched the directories
2861 mentioned in libthread-db-search-path. If you want to search those
2862 directories, they must be specified in libthread-db-search-path.
2863 The default value of libthread-db-search-path on GNU/Linux and Solaris
2864 systems is now "$sdir:$pdir".
2866 $pdir is not supported by gdbserver, it is currently ignored.
2867 $sdir is supported by gdbserver.
2869 * New configure option --with-iconv-bin.
2870 When using the internationalization support like the one in the GNU C
2871 library, GDB will invoke the "iconv" program to get a list of supported
2872 character sets. If this program lives in a non-standard location, one can
2873 use this option to specify where to find it.
2875 * When natively debugging programs on PowerPC BookE processors running
2876 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2877 watchpoints, which specify a mask in addition to an address to watch.
2878 The mask specifies that some bits of an address (the bits which are
2879 reset in the mask) should be ignored when matching the address accessed
2880 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2881 section in the user manual for more details.
2883 * The new option --once causes GDBserver to stop listening for connections once
2884 the first connection is made. The listening port used by GDBserver will
2885 become available after that.
2887 * New commands "info macros" and "alias" have been added.
2889 * New function parameters suffix @entry specifies value of function parameter
2890 at the time the function got called. Entry values are available only since
2896 "!" is now an alias of the "shell" command.
2897 Note that no space is needed between "!" and SHELL COMMAND.
2901 watch EXPRESSION mask MASK_VALUE
2902 The watch command now supports the mask argument which allows creation
2903 of masked watchpoints, if the current architecture supports this feature.
2905 info auto-load-scripts [REGEXP]
2906 This command was formerly named "maintenance print section-scripts".
2907 It is now generally useful and is no longer a maintenance-only command.
2909 info macro [-all] [--] MACRO
2910 The info macro command has new options `-all' and `--'. The first for
2911 printing all definitions of a macro. The second for explicitly specifying
2912 the end of arguments and the beginning of the macro name in case the macro
2913 name starts with a hyphen.
2915 collect[/s] EXPRESSIONS
2916 The tracepoint collect command now takes an optional modifier "/s"
2917 that directs it to dereference pointer-to-character types and
2918 collect the bytes of memory up to a zero byte. The behavior is
2919 similar to what you see when you use the regular print command on a
2920 string. An optional integer following the "/s" sets a bound on the
2921 number of bytes that will be collected.
2924 The trace start command now interprets any supplied arguments as a
2925 note to be recorded with the trace run, with an effect similar to
2926 setting the variable trace-notes.
2929 The trace stop command now interprets any arguments as a note to be
2930 mentioned along with the tstatus report that the trace was stopped
2931 with a command. The effect is similar to setting the variable
2934 * Tracepoints can now be enabled and disabled at any time after a trace
2935 experiment has been started using the standard "enable" and "disable"
2936 commands. It is now possible to start a trace experiment with no enabled
2937 tracepoints; GDB will display a warning, but will allow the experiment to
2938 begin, assuming that tracepoints will be enabled as needed while the trace
2941 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2942 locations with 4-byte instructions, when they were previously
2943 limited to locations with instructions of 5 bytes or longer.
2947 set debug dwarf2-read
2948 show debug dwarf2-read
2949 Turns on or off display of debugging messages related to reading
2950 DWARF debug info. The default is off.
2952 set debug symtab-create
2953 show debug symtab-create
2954 Turns on or off display of debugging messages related to symbol table
2955 creation. The default is off.
2958 show extended-prompt
2959 Set the GDB prompt, and allow escape sequences to be inserted to
2960 display miscellaneous information (see 'help set extended-prompt'
2961 for the list of sequences). This prompt (and any information
2962 accessed through the escape sequences) is updated every time the
2963 prompt is displayed.
2965 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2966 show print entry-values
2967 Set printing of frame argument values at function entry. In some cases
2968 GDB can determine the value of function argument which was passed by the
2969 function caller, even if the value was modified inside the called function.
2971 set debug entry-values
2972 show debug entry-values
2973 Control display of debugging info for determining frame argument values at
2974 function entry and virtual tail call frames.
2976 set basenames-may-differ
2977 show basenames-may-differ
2978 Set whether a source file may have multiple base names.
2979 (A "base name" is the name of a file with the directory part removed.
2980 Example: The base name of "/home/user/hello.c" is "hello.c".)
2981 If set, GDB will canonicalize file names (e.g., expand symlinks)
2982 before comparing them. Canonicalization is an expensive operation,
2983 but it allows the same file be known by more than one base name.
2984 If not set (the default), all source files are assumed to have just
2985 one base name, and gdb will do file name comparisons more efficiently.
2991 Set a user name and notes for the current and any future trace runs.
2992 This is useful for long-running and/or disconnected traces, to
2993 inform others (or yourself) as to who is running the trace, supply
2994 contact information, or otherwise explain what is going on.
2996 set trace-stop-notes
2997 show trace-stop-notes
2998 Set a note attached to the trace run, that is displayed when the
2999 trace has been stopped by a tstop command. This is useful for
3000 instance as an explanation, if you are stopping a trace run that was
3001 started by someone else.
3003 * New remote packets
3007 Dynamically enable a tracepoint in a started trace experiment.
3011 Dynamically disable a tracepoint in a started trace experiment.
3015 Set the user and notes of the trace run.
3019 Query the current status of a tracepoint.
3023 Query the minimum length of instruction at which a fast tracepoint may
3026 * Dcache size (number of lines) and line-size are now runtime-configurable
3027 via "set dcache line" and "set dcache line-size" commands.
3031 Texas Instruments TMS320C6x tic6x-*-*
3035 Renesas RL78 rl78-*-elf
3037 *** Changes in GDB 7.3.1
3039 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3041 *** Changes in GDB 7.3
3043 * GDB has a new command: "thread find [REGEXP]".
3044 It finds the thread id whose name, target id, or thread extra info
3045 matches the given regular expression.
3047 * The "catch syscall" command now works on mips*-linux* targets.
3049 * The -data-disassemble MI command now supports modes 2 and 3 for
3050 dumping the instruction opcodes.
3052 * New command line options
3054 -data-directory DIR Specify DIR as the "data-directory".
3055 This is mostly for testing purposes.
3057 * The "maint set python auto-load on|off" command has been renamed to
3058 "set auto-load-scripts on|off".
3060 * GDB has a new command: "set directories".
3061 It is like the "dir" command except that it replaces the
3062 source path list instead of augmenting it.
3064 * GDB now understands thread names.
3066 On GNU/Linux, "info threads" will display the thread name as set by
3067 prctl or pthread_setname_np.
3069 There is also a new command, "thread name", which can be used to
3070 assign a name internally for GDB to display.
3073 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3074 has been integrated into GDB.
3078 ** The function gdb.Write now accepts an optional keyword 'stream'.
3079 This keyword, when provided, will direct the output to either
3080 stdout, stderr, or GDB's logging output.
3082 ** Parameters can now be be sub-classed in Python, and in particular
3083 you may implement the get_set_doc and get_show_doc functions.
3084 This improves how Parameter set/show documentation is processed
3085 and allows for more dynamic content.
3087 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3088 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3089 have an is_valid method.
3091 ** Breakpoints can now be sub-classed in Python, and in particular
3092 you may implement a 'stop' function that is executed each time
3093 the inferior reaches that breakpoint.
3095 ** New function gdb.lookup_global_symbol looks up a global symbol.
3097 ** GDB values in Python are now callable if the value represents a
3098 function. For example, if 'some_value' represents a function that
3099 takes two integer parameters and returns a value, you can call
3100 that function like so:
3102 result = some_value (10,20)
3104 ** Module gdb.types has been added.
3105 It contains a collection of utilities for working with gdb.Types objects:
3106 get_basic_type, has_field, make_enum_dict.
3108 ** Module gdb.printing has been added.
3109 It contains utilities for writing and registering pretty-printers.
3110 New classes: PrettyPrinter, SubPrettyPrinter,
3111 RegexpCollectionPrettyPrinter.
3112 New function: register_pretty_printer.
3114 ** New commands "info pretty-printers", "enable pretty-printer" and
3115 "disable pretty-printer" have been added.
3117 ** gdb.parameter("directories") is now available.
3119 ** New function gdb.newest_frame returns the newest frame in the
3122 ** The gdb.InferiorThread class has a new "name" attribute. This
3123 holds the thread's name.
3125 ** Python Support for Inferior events.
3126 Python scripts can add observers to be notified of events
3127 occurring in the process being debugged.
3128 The following events are currently supported:
3129 - gdb.events.cont Continue event.
3130 - gdb.events.exited Inferior exited event.
3131 - gdb.events.stop Signal received, and Breakpoint hit events.
3135 ** GDB now puts template parameters in scope when debugging in an
3136 instantiation. For example, if you have:
3138 template<int X> int func (void) { return X; }
3140 then if you step into func<5>, "print X" will show "5". This
3141 feature requires proper debuginfo support from the compiler; it
3142 was added to GCC 4.5.
3144 ** The motion commands "next", "finish", "until", and "advance" now
3145 work better when exceptions are thrown. In particular, GDB will
3146 no longer lose control of the inferior; instead, the GDB will
3147 stop the inferior at the point at which the exception is caught.
3148 This functionality requires a change in the exception handling
3149 code that was introduced in GCC 4.5.
3151 * GDB now follows GCC's rules on accessing volatile objects when
3152 reading or writing target state during expression evaluation.
3153 One notable difference to prior behavior is that "print x = 0"
3154 no longer generates a read of x; the value of the assignment is
3155 now always taken directly from the value being assigned.
3157 * GDB now has some support for using labels in the program's source in
3158 linespecs. For instance, you can use "advance label" to continue
3159 execution to a label.
3161 * GDB now has support for reading and writing a new .gdb_index
3162 section. This section holds a fast index of DWARF debugging
3163 information and can be used to greatly speed up GDB startup and
3164 operation. See the documentation for `save gdb-index' for details.
3166 * The "watch" command now accepts an optional "-location" argument.
3167 When used, this causes GDB to watch the memory referred to by the
3168 expression. Such a watchpoint is never deleted due to it going out
3171 * GDB now supports thread debugging of core dumps on GNU/Linux.
3173 GDB now activates thread debugging using the libthread_db library
3174 when debugging GNU/Linux core dumps, similarly to when debugging
3175 live processes. As a result, when debugging a core dump file, GDB
3176 is now able to display pthread_t ids of threads. For example, "info
3177 threads" shows the same output as when debugging the process when it
3178 was live. In earlier releases, you'd see something like this:
3181 * 1 LWP 6780 main () at main.c:10
3183 While now you see this:
3186 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3188 It is also now possible to inspect TLS variables when debugging core
3191 When debugging a core dump generated on a machine other than the one
3192 used to run GDB, you may need to point GDB at the correct
3193 libthread_db library with the "set libthread-db-search-path"
3194 command. See the user manual for more details on this command.
3196 * When natively debugging programs on PowerPC BookE processors running
3197 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3198 which stop execution of the inferior whenever it executes an instruction
3199 at any address within the specified range. See the "PowerPC Embedded"
3200 section in the user manual for more details.
3202 * New features in the GDB remote stub, GDBserver
3204 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3205 and i686 LynxOS (version 5.x).
3207 ** GDBserver is now supported on Blackfin Linux.
3209 * New native configurations
3211 ia64 HP-UX ia64-*-hpux*
3215 Analog Devices, Inc. Blackfin Processor bfin-*
3217 * Ada task switching is now supported on sparc-elf targets when
3218 debugging a program using the Ravenscar Profile. For more information,
3219 see the "Tasking Support when using the Ravenscar Profile" section
3220 in the GDB user manual.
3222 * Guile support was removed.
3224 * New features in the GNU simulator
3226 ** The --map-info flag lists all known core mappings.
3228 ** CFI flashes may be simulated via the "cfi" device.
3230 *** Changes in GDB 7.2
3232 * Shared library support for remote targets by default
3234 When GDB is configured for a generic, non-OS specific target, like
3235 for example, --target=arm-eabi or one of the many *-*-elf targets,
3236 GDB now queries remote stubs for loaded shared libraries using the
3237 `qXfer:libraries:read' packet. Previously, shared library support
3238 was always disabled for such configurations.
3242 ** Argument Dependent Lookup (ADL)
3244 In C++ ADL lookup directs function search to the namespaces of its
3245 arguments even if the namespace has not been imported.
3255 Here the compiler will search for `foo' in the namespace of 'b'
3256 and find A::foo. GDB now supports this. This construct is commonly
3257 used in the Standard Template Library for operators.
3259 ** Improved User Defined Operator Support
3261 In addition to member operators, GDB now supports lookup of operators
3262 defined in a namespace and imported with a `using' directive, operators
3263 defined in the global scope, operators imported implicitly from an
3264 anonymous namespace, and the ADL operators mentioned in the previous
3266 GDB now also supports proper overload resolution for all the previously
3267 mentioned flavors of operators.
3269 ** static const class members
3271 Printing of static const class members that are initialized in the
3272 class definition has been fixed.
3274 * Windows Thread Information Block access.
3276 On Windows targets, GDB now supports displaying the Windows Thread
3277 Information Block (TIB) structure. This structure is visible either
3278 by using the new command `info w32 thread-information-block' or, by
3279 dereferencing the new convenience variable named `$_tlb', a
3280 thread-specific pointer to the TIB. This feature is also supported
3281 when remote debugging using GDBserver.
3283 * Static tracepoints
3285 Static tracepoints are calls in the user program into a tracing
3286 library. One such library is a port of the LTTng kernel tracer to
3287 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3288 When debugging with GDBserver, GDB now supports combining the GDB
3289 tracepoint machinery with such libraries. For example: the user can
3290 use GDB to probe a static tracepoint marker (a call from the user
3291 program into the tracing library) with the new "strace" command (see
3292 "New commands" below). This creates a "static tracepoint" in the
3293 breakpoint list, that can be manipulated with the same feature set
3294 as fast and regular tracepoints. E.g., collect registers, local and
3295 global variables, collect trace state variables, and define
3296 tracepoint conditions. In addition, the user can collect extra
3297 static tracepoint marker specific data, by collecting the new
3298 $_sdata internal variable. When analyzing the trace buffer, you can
3299 inspect $_sdata like any other variable available to GDB. For more
3300 information, see the "Tracepoints" chapter in GDB user manual. New
3301 remote packets have been defined to support static tracepoints, see
3302 the "New remote packets" section below.
3304 * Better reconstruction of tracepoints after disconnected tracing
3306 GDB will attempt to download the original source form of tracepoint
3307 definitions when starting a trace run, and then will upload these
3308 upon reconnection to the target, resulting in a more accurate
3309 reconstruction of the tracepoints that are in use on the target.
3313 You can now exercise direct control over the ways that GDB can
3314 affect your program. For instance, you can disallow the setting of
3315 breakpoints, so that the program can run continuously (assuming
3316 non-stop mode). In addition, the "observer" variable is available
3317 to switch all of the different controls; in observer mode, GDB
3318 cannot affect the target's behavior at all, which is useful for
3319 tasks like diagnosing live systems in the field.
3321 * The new convenience variable $_thread holds the number of the
3324 * New remote packets
3328 Return the address of the Windows Thread Information Block of a given thread.
3332 In response to several of the tracepoint packets, the target may now
3333 also respond with a number of intermediate `qRelocInsn' request
3334 packets before the final result packet, to have GDB handle
3335 relocating an instruction to execute at a different address. This
3336 is particularly useful for stubs that support fast tracepoints. GDB
3337 reports support for this feature in the qSupported packet.
3341 List static tracepoint markers in the target program.
3345 List static tracepoint markers at a given address in the target
3348 qXfer:statictrace:read
3350 Read the static trace data collected (by a `collect $_sdata'
3351 tracepoint action). The remote stub reports support for this packet
3352 to gdb's qSupported query.
3356 Send the current settings of GDB's permission flags.
3360 Send part of the source (textual) form of a tracepoint definition,
3361 which includes location, conditional, and action list.
3363 * The source command now accepts a -s option to force searching for the
3364 script in the source search path even if the script name specifies
3367 * New features in the GDB remote stub, GDBserver
3369 - GDBserver now support tracepoints (including fast tracepoints, and
3370 static tracepoints). The feature is currently supported by the
3371 i386-linux and amd64-linux builds. See the "Tracepoints support
3372 in gdbserver" section in the manual for more information.
3374 GDBserver JIT compiles the tracepoint's conditional agent
3375 expression bytecode into native code whenever possible for low
3376 overhead dynamic tracepoints conditionals. For such tracepoints,
3377 an expression that examines program state is evaluated when the
3378 tracepoint is reached, in order to determine whether to capture
3379 trace data. If the condition is simple and false, processing the
3380 tracepoint finishes very quickly and no data is gathered.
3382 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3383 for static tracepoints support.
3385 - GDBserver now supports x86_64 Windows 64-bit debugging.
3387 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3388 it understands register description.
3390 * The --batch flag now disables pagination and queries.
3392 * X86 general purpose registers
3394 GDB now supports reading/writing byte, word and double-word x86
3395 general purpose registers directly. This means you can use, say,
3396 $ah or $ax to refer, respectively, to the byte register AH and
3397 16-bit word register AX that are actually portions of the 32-bit
3398 register EAX or 64-bit register RAX.
3400 * The `commands' command now accepts a range of breakpoints to modify.
3401 A plain `commands' following a command that creates multiple
3402 breakpoints affects all the breakpoints set by that command. This
3403 applies to breakpoints set by `rbreak', and also applies when a
3404 single `break' command creates multiple breakpoints (e.g.,
3405 breakpoints on overloaded c++ functions).
3407 * The `rbreak' command now accepts a filename specification as part of
3408 its argument, limiting the functions selected by the regex to those
3409 in the specified file.
3411 * Support for remote debugging Windows and SymbianOS shared libraries
3412 from Unix hosts has been improved. Non Windows GDB builds now can
3413 understand target reported file names that follow MS-DOS based file
3414 system semantics, such as file names that include drive letters and
3415 use the backslash character as directory separator. This makes it
3416 possible to transparently use the "set sysroot" and "set
3417 solib-search-path" on Unix hosts to point as host copies of the
3418 target's shared libraries. See the new command "set
3419 target-file-system-kind" described below, and the "Commands to
3420 specify files" section in the user manual for more information.
3424 eval template, expressions...
3425 Convert the values of one or more expressions under the control
3426 of the string template to a command line, and call it.
3428 set target-file-system-kind unix|dos-based|auto
3429 show target-file-system-kind
3430 Set or show the assumed file system kind for target reported file
3433 save breakpoints <filename>
3434 Save all current breakpoint definitions to a file suitable for use
3435 in a later debugging session. To read the saved breakpoint
3436 definitions, use the `source' command.
3438 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3441 info static-tracepoint-markers
3442 Display information about static tracepoint markers in the target.
3444 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3445 Define a static tracepoint by probing a marker at the given
3446 function, line, address, or marker ID.
3450 Enable and disable observer mode.
3452 set may-write-registers on|off
3453 set may-write-memory on|off
3454 set may-insert-breakpoints on|off
3455 set may-insert-tracepoints on|off
3456 set may-insert-fast-tracepoints on|off
3457 set may-interrupt on|off
3458 Set individual permissions for GDB effects on the target. Note that
3459 some of these settings can have undesirable or surprising
3460 consequences, particularly when changed in the middle of a session.
3461 For instance, disabling the writing of memory can prevent
3462 breakpoints from being inserted, cause single-stepping to fail, or
3463 even crash your program, if you disable after breakpoints have been
3464 inserted. However, GDB should not crash.
3466 set record memory-query on|off
3467 show record memory-query
3468 Control whether to stop the inferior if memory changes caused
3469 by an instruction cannot be recorded.
3474 The disassemble command now supports "start,+length" form of two arguments.
3478 ** GDB now provides a new directory location, called the python directory,
3479 where Python scripts written for GDB can be installed. The location
3480 of that directory is <data-directory>/python, where <data-directory>
3481 is the GDB data directory. For more details, see section `Scripting
3482 GDB using Python' in the manual.
3484 ** The GDB Python API now has access to breakpoints, symbols, symbol
3485 tables, program spaces, inferiors, threads and frame's code blocks.
3486 Additionally, GDB Parameters can now be created from the API, and
3487 manipulated via set/show in the CLI.
3489 ** New functions gdb.target_charset, gdb.target_wide_charset,
3490 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3492 ** New exception gdb.GdbError.
3494 ** Pretty-printers are now also looked up in the current program space.
3496 ** Pretty-printers can now be individually enabled and disabled.
3498 ** GDB now looks for names of Python scripts to auto-load in a
3499 special section named `.debug_gdb_scripts', in addition to looking
3500 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3502 * Tracepoint actions were unified with breakpoint commands. In particular,
3503 there are no longer differences in "info break" output for breakpoints and
3504 tracepoints and the "commands" command can be used for both tracepoints and
3505 regular breakpoints.
3509 ARM Symbian arm*-*-symbianelf*
3511 * D language support.
3512 GDB now supports debugging programs written in the D programming
3515 * GDB now supports the extended ptrace interface for PowerPC which is
3516 available since Linux kernel version 2.6.34. This automatically enables
3517 any hardware breakpoints and additional hardware watchpoints available in
3518 the processor. The old ptrace interface exposes just one hardware
3519 watchpoint and no hardware breakpoints.
3521 * GDB is now able to use the Data Value Compare (DVC) register available on
3522 embedded PowerPC processors to implement in hardware simple watchpoint
3523 conditions of the form:
3525 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3527 This works in native GDB running on Linux kernels with the extended ptrace
3528 interface mentioned above.
3530 *** Changes in GDB 7.1
3534 ** Namespace Support
3536 GDB now supports importing of namespaces in C++. This enables the
3537 user to inspect variables from imported namespaces. Support for
3538 namepace aliasing has also been added. So, if a namespace is
3539 aliased in the current scope (e.g. namepace C=A; ) the user can
3540 print variables using the alias (e.g. (gdb) print C::x).
3544 All known bugs relating to the printing of virtual base class were
3545 fixed. It is now possible to call overloaded static methods using a
3550 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3551 and reinterpret_cast<> are now handled by the C++ expression parser.
3555 Xilinx MicroBlaze microblaze-*-*
3560 Xilinx MicroBlaze microblaze
3563 * Multi-program debugging.
3565 GDB now has support for multi-program (a.k.a. multi-executable or
3566 multi-exec) debugging. This allows for debugging multiple inferiors
3567 simultaneously each running a different program under the same GDB
3568 session. See "Debugging Multiple Inferiors and Programs" in the
3569 manual for more information. This implied some user visible changes
3570 in the multi-inferior support. For example, "info inferiors" now
3571 lists inferiors that are not running yet or that have exited
3572 already. See also "New commands" and "New options" below.
3574 * New tracing features
3576 GDB's tracepoint facility now includes several new features:
3578 ** Trace state variables
3580 GDB tracepoints now include support for trace state variables, which
3581 are variables managed by the target agent during a tracing
3582 experiment. They are useful for tracepoints that trigger each
3583 other, so for instance one tracepoint can count hits in a variable,
3584 and then a second tracepoint has a condition that is true when the
3585 count reaches a particular value. Trace state variables share the
3586 $-syntax of GDB convenience variables, and can appear in both
3587 tracepoint actions and condition expressions. Use the "tvariable"
3588 command to create, and "info tvariables" to view; see "Trace State
3589 Variables" in the manual for more detail.
3593 GDB now includes an option for defining fast tracepoints, which
3594 targets may implement more efficiently, such as by installing a jump
3595 into the target agent rather than a trap instruction. The resulting
3596 speedup can be by two orders of magnitude or more, although the
3597 tradeoff is that some program locations on some target architectures
3598 might not allow fast tracepoint installation, for instance if the
3599 instruction to be replaced is shorter than the jump. To request a
3600 fast tracepoint, use the "ftrace" command, with syntax identical to
3601 the regular trace command.
3603 ** Disconnected tracing
3605 It is now possible to detach GDB from the target while it is running
3606 a trace experiment, then reconnect later to see how the experiment
3607 is going. In addition, a new variable disconnected-tracing lets you
3608 tell the target agent whether to continue running a trace if the
3609 connection is lost unexpectedly.
3613 GDB now has the ability to save the trace buffer into a file, and
3614 then use that file as a target, similarly to you can do with
3615 corefiles. You can select trace frames, print data that was
3616 collected in them, and use tstatus to display the state of the
3617 tracing run at the moment that it was saved. To create a trace
3618 file, use "tsave <filename>", and to use it, do "target tfile
3621 ** Circular trace buffer
3623 You can ask the target agent to handle the trace buffer as a
3624 circular buffer, discarding the oldest trace frames to make room for
3625 newer ones, by setting circular-trace-buffer to on. This feature may
3626 not be available for all target agents.
3631 The disassemble command, when invoked with two arguments, now requires
3632 the arguments to be comma-separated.
3635 The info variables command now displays variable definitions. Files
3636 which only declare a variable are not shown.
3639 The source command is now capable of sourcing Python scripts.
3640 This feature is dependent on the debugger being build with Python
3643 Related to this enhancement is also the introduction of a new command
3644 "set script-extension" (see below).
3646 * New commands (for set/show, see "New options" below)
3648 record save [<FILENAME>]
3649 Save a file (in core file format) containing the process record
3650 execution log for replay debugging at a later time.
3652 record restore <FILENAME>
3653 Restore the process record execution log that was saved at an
3654 earlier time, for replay debugging.
3656 add-inferior [-copies <N>] [-exec <FILENAME>]
3659 clone-inferior [-copies <N>] [ID]
3660 Make a new inferior ready to execute the same program another
3661 inferior has loaded.
3666 maint info program-spaces
3667 List the program spaces loaded into GDB.
3669 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3670 show remote interrupt-sequence
3671 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3672 as the sequence to the remote target in order to interrupt the execution.
3673 Ctrl-C is a default. Some system prefers BREAK which is high level of
3674 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3675 Magic SysRq g. It is BREAK signal and character 'g'.
3677 set remote interrupt-on-connect [on | off]
3678 show remote interrupt-on-connect
3679 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3680 remote target when gdb connects to it. This is needed when you debug
3683 set remotebreak [on | off]
3685 Deprecated. Use "set/show remote interrupt-sequence" instead.
3687 tvariable $NAME [ = EXP ]
3688 Create or modify a trace state variable.
3691 List trace state variables and their values.
3693 delete tvariable $NAME ...
3694 Delete one or more trace state variables.
3697 Evaluate the given expressions without collecting anything into the
3698 trace buffer. (Valid in tracepoint actions only.)
3700 ftrace FN / FILE:LINE / *ADDR
3701 Define a fast tracepoint at the given function, line, or address.
3703 * New expression syntax
3705 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3706 GDB now parses 0b101010 identically with 42.
3710 set follow-exec-mode new|same
3711 show follow-exec-mode
3712 Control whether GDB reuses the same inferior across an exec call or
3713 creates a new one. This is useful to be able to restart the old
3714 executable after the inferior having done an exec call.
3716 set default-collect EXPR, ...
3717 show default-collect
3718 Define a list of expressions to be collected at each tracepoint.
3719 This is a useful way to ensure essential items are not overlooked,
3720 such as registers or a critical global variable.
3722 set disconnected-tracing
3723 show disconnected-tracing
3724 If set to 1, the target is instructed to continue tracing if it
3725 loses its connection to GDB. If 0, the target is to stop tracing
3728 set circular-trace-buffer
3729 show circular-trace-buffer
3730 If set to on, the target is instructed to use a circular trace buffer
3731 and discard the oldest trace frames instead of stopping the trace due
3732 to a full trace buffer. If set to off, the trace stops when the buffer
3733 fills up. Some targets may not support this.
3735 set script-extension off|soft|strict
3736 show script-extension
3737 If set to "off", the debugger does not perform any script language
3738 recognition, and all sourced files are assumed to be GDB scripts.
3739 If set to "soft" (the default), files are sourced according to
3740 filename extension, falling back to GDB scripts if the first
3742 If set to "strict", files are sourced according to filename extension.
3744 set ada trust-PAD-over-XVS on|off
3745 show ada trust-PAD-over-XVS
3746 If off, activate a workaround against a bug in the debugging information
3747 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3748 the GCC sources for more information about the GNAT encoding and
3749 PAD types in particular). It is always safe to set this option to
3750 off, but this introduces a slight performance penalty. The default
3753 * Python API Improvements
3755 ** GDB provides the new class gdb.LazyString. This is useful in
3756 some pretty-printing cases. The new method gdb.Value.lazy_string
3757 provides a simple way to create objects of this type.
3759 ** The fields returned by gdb.Type.fields now have an
3760 `is_base_class' attribute.
3762 ** The new method gdb.Type.range returns the range of an array type.
3764 ** The new method gdb.parse_and_eval can be used to parse and
3765 evaluate an expression.
3767 * New remote packets
3770 Define a trace state variable.
3773 Get the current value of a trace state variable.
3776 Set desired tracing behavior upon disconnection.
3779 Set the trace buffer to be linear or circular.
3782 Get data about the tracepoints currently in use.
3786 Process record now works correctly with hardware watchpoints.
3788 Multiple bug fixes have been made to the mips-irix port, making it
3789 much more reliable. In particular:
3790 - Debugging threaded applications is now possible again. Previously,
3791 GDB would hang while starting the program, or while waiting for
3792 the program to stop at a breakpoint.
3793 - Attaching to a running process no longer hangs.
3794 - An error occurring while loading a core file has been fixed.
3795 - Changing the value of the PC register now works again. This fixes
3796 problems observed when using the "jump" command, or when calling
3797 a function from GDB, or even when assigning a new value to $pc.
3798 - With the "finish" and "return" commands, the return value for functions
3799 returning a small array is now correctly printed.
3800 - It is now possible to break on shared library code which gets executed
3801 during a shared library init phase (code executed while executing
3802 their .init section). Previously, the breakpoint would have no effect.
3803 - GDB is now able to backtrace through the signal handler for
3804 non-threaded programs.
3806 PIE (Position Independent Executable) programs debugging is now supported.
3807 This includes debugging execution of PIC (Position Independent Code) shared
3808 libraries although for that, it should be possible to run such libraries as an
3811 *** Changes in GDB 7.0
3813 * GDB now has an interface for JIT compilation. Applications that
3814 dynamically generate code can create symbol files in memory and register
3815 them with GDB. For users, the feature should work transparently, and
3816 for JIT developers, the interface is documented in the GDB manual in the
3817 "JIT Compilation Interface" chapter.
3819 * Tracepoints may now be conditional. The syntax is as for
3820 breakpoints; either an "if" clause appended to the "trace" command,
3821 or the "condition" command is available. GDB sends the condition to
3822 the target for evaluation using the same bytecode format as is used
3823 for tracepoint actions.
3825 * The disassemble command now supports: an optional /r modifier, print the
3826 raw instructions in hex as well as in symbolic form, and an optional /m
3827 modifier to print mixed source+assembly.
3829 * Process record and replay
3831 In a architecture environment that supports ``process record and
3832 replay'', ``process record and replay'' target can record a log of
3833 the process execution, and replay it with both forward and reverse
3836 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3837 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3838 set execution-direction {forward|reverse}, for targets that support
3841 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3842 feature is available with a native GDB running on kernel version
3845 * GDB now has support for multi-byte and wide character sets on the
3846 target. Strings whose character type is wchar_t, char16_t, or
3847 char32_t are now correctly printed. GDB supports wide- and unicode-
3848 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3849 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3850 `printf'. This feature requires iconv to work properly; if your
3851 system does not have a working iconv, GDB can use GNU libiconv. See
3852 the installation instructions for more information.
3854 * GDB now supports automatic retrieval of shared library files from
3855 remote targets. To use this feature, specify a system root that begins
3856 with the `remote:' prefix, either via the `set sysroot' command or via
3857 the `--with-sysroot' configure-time option.
3859 * "info sharedlibrary" now takes an optional regex of libraries to show,
3860 and it now reports if a shared library has no debugging information.
3862 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3863 now complete on file names.
3865 * When completing in expressions, gdb will attempt to limit
3866 completions to allowable structure or union fields, where appropriate.
3867 For instance, consider:
3869 # struct example { int f1; double f2; };
3870 # struct example variable;
3873 If the user types TAB at the end of this command line, the available
3874 completions will be "f1" and "f2".
3876 * Inlined functions are now supported. They show up in backtraces, and
3877 the "step", "next", and "finish" commands handle them automatically.
3879 * GDB now supports the token-splicing (##) and stringification (#)
3880 operators when expanding macros. It also supports variable-arity
3883 * GDB now supports inspecting extra signal information, exported by
3884 the new $_siginfo convenience variable. The feature is currently
3885 implemented on linux ARM, i386 and amd64.
3887 * GDB can now display the VFP floating point registers and NEON vector
3888 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3889 can provide these registers (requires Linux 2.6.30 or later). Remote
3890 and simulator targets may also provide them.
3892 * New remote packets
3895 Search memory for a sequence of bytes.
3898 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3899 operation over reliable transport links. Use of this packet is
3900 controlled by the `set remote noack-packet' command.
3903 Kill the process with the specified process ID. Use this in preference
3904 to `k' when multiprocess protocol extensions are supported.
3907 Obtains additional operating system information
3911 Read or write additional signal information.
3913 * Removed remote protocol undocumented extension
3915 An undocumented extension to the remote protocol's `S' stop reply
3916 packet that permited the stub to pass a process id was removed.
3917 Remote servers should use the `T' stop reply packet instead.
3919 * GDB now supports multiple function calling conventions according to the
3920 DWARF-2 DW_AT_calling_convention function attribute.
3922 * The SH target utilizes the aforementioned change to distinguish between gcc
3923 and Renesas calling convention. It also adds the new CLI commands
3924 `set/show sh calling-convention'.
3926 * GDB can now read compressed debug sections, as produced by GNU gold
3927 with the --compress-debug-sections=zlib flag.
3929 * 64-bit core files are now supported on AIX.
3931 * Thread switching is now supported on Tru64.
3933 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3934 which will be allocated using malloc later in program execution.
3936 * The qXfer:libraries:read remote procotol packet now allows passing a
3937 list of section offsets.
3939 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3940 conditions handling signals delivered during attach or thread creation
3941 have also been fixed.
3943 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3944 From the user's standpoint, all unqualified instances of True and False
3945 are treated as the standard definitions, regardless of context.
3947 * GDB now parses C++ symbol and type names more flexibly. For
3950 template<typename T> class C { };
3953 GDB will now correctly handle all of:
3955 ptype C<char const *>
3956 ptype C<char const*>
3957 ptype C<const char *>
3958 ptype C<const char*>
3960 * New features in the GDB remote stub, gdbserver
3962 - The "--wrapper" command-line argument tells gdbserver to use a
3963 wrapper program to launch programs for debugging.
3965 - On PowerPC and S/390 targets, it is now possible to use a single
3966 gdbserver executable to debug both 32-bit and 64-bit programs.
3967 (This requires gdbserver itself to be built as a 64-bit executable.)
3969 - gdbserver uses the new noack protocol mode for TCP connections to
3970 reduce communications latency, if also supported and enabled in GDB.
3972 - Support for the sparc64-linux-gnu target is now included in
3975 - The amd64-linux build of gdbserver now supports debugging both
3976 32-bit and 64-bit programs.
3978 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3979 now support hardware watchpoints, and will use them automatically
3984 GDB now has support for scripting using Python. Whether this is
3985 available is determined at configure time.
3987 New GDB commands can now be written in Python.
3989 * Ada tasking support
3991 Ada tasks can now be inspected in GDB. The following commands have
3995 Print the list of Ada tasks.
3997 Print detailed information about task number N.
3999 Print the task number of the current task.
4001 Switch the context of debugging to task number N.
4003 * Support for user-defined prefixed commands. The "define" command can
4004 add new commands to existing prefixes, e.g. "target".
4006 * Multi-inferior, multi-process debugging.
4008 GDB now has generalized support for multi-inferior debugging. See
4009 "Debugging Multiple Inferiors" in the manual for more information.
4010 Although availability still depends on target support, the command
4011 set is more uniform now. The GNU/Linux specific multi-forks support
4012 has been migrated to this new framework. This implied some user
4013 visible changes; see "New commands" and also "Removed commands"
4016 * Target descriptions can now describe the target OS ABI. See the
4017 "Target Description Format" section in the user manual for more
4020 * Target descriptions can now describe "compatible" architectures
4021 to indicate that the target can execute applications for a different
4022 architecture in addition to those for the main target architecture.
4023 See the "Target Description Format" section in the user manual for
4026 * Multi-architecture debugging.
4028 GDB now includes general supports for debugging applications on
4029 hybrid systems that use more than one single processor architecture
4030 at the same time. Each such hybrid architecture still requires
4031 specific support to be added. The only hybrid architecture supported
4032 in this version of GDB is the Cell Broadband Engine.
4034 * GDB now supports integrated debugging of Cell/B.E. applications that
4035 use both the PPU and SPU architectures. To enable support for hybrid
4036 Cell/B.E. debugging, you need to configure GDB to support both the
4037 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4038 --enable-targets configure option.
4040 * Non-stop mode debugging.
4042 For some targets, GDB now supports an optional mode of operation in
4043 which you can examine stopped threads while other threads continue
4044 to execute freely. This is referred to as non-stop mode, with the
4045 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4046 section in the user manual for more information.
4048 To be able to support remote non-stop debugging, a remote stub needs
4049 to implement the non-stop mode remote protocol extensions, as
4050 described in the "Remote Non-Stop" section of the user manual. The
4051 GDB remote stub, gdbserver, has been adjusted to support these
4052 extensions on linux targets.
4054 * New commands (for set/show, see "New options" below)
4056 catch syscall [NAME(S) | NUMBER(S)]
4057 Catch system calls. Arguments, which should be names of system
4058 calls or their numbers, mean catch only those syscalls. Without
4059 arguments, every syscall will be caught. When the inferior issues
4060 any of the specified syscalls, GDB will stop and announce the system
4061 call, both when it is called and when its call returns. This
4062 feature is currently available with a native GDB running on the
4063 Linux Kernel, under the following architectures: x86, x86_64,
4064 PowerPC and PowerPC64.
4066 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4068 Search memory for a sequence of bytes.
4070 maint set python print-stack
4071 maint show python print-stack
4072 Show a stack trace when an error is encountered in a Python script.
4075 Invoke CODE by passing it to the Python interpreter.
4080 These allow macros to be defined, undefined, and listed
4084 Show operating system information about processes.
4087 List the inferiors currently under GDB's control.
4090 Switch focus to inferior number NUM.
4093 Detach from inferior number NUM.
4096 Kill inferior number NUM.
4100 set spu stop-on-load
4101 show spu stop-on-load
4102 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4104 set spu auto-flush-cache
4105 show spu auto-flush-cache
4106 Control whether to automatically flush the software-managed cache
4107 during Cell/B.E. debugging.
4109 set sh calling-convention
4110 show sh calling-convention
4111 Control the calling convention used when calling SH target functions.
4114 show debug timestamp
4115 Control display of timestamps with GDB debugging output.
4117 set disassemble-next-line
4118 show disassemble-next-line
4119 Control display of disassembled source lines or instructions when
4122 set remote noack-packet
4123 show remote noack-packet
4124 Set/show the use of remote protocol QStartNoAckMode packet. See above
4125 under "New remote packets."
4127 set remote query-attached-packet
4128 show remote query-attached-packet
4129 Control use of remote protocol `qAttached' (query-attached) packet.
4131 set remote read-siginfo-object
4132 show remote read-siginfo-object
4133 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4136 set remote write-siginfo-object
4137 show remote write-siginfo-object
4138 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4141 set remote reverse-continue
4142 show remote reverse-continue
4143 Control use of remote protocol 'bc' (reverse-continue) packet.
4145 set remote reverse-step
4146 show remote reverse-step
4147 Control use of remote protocol 'bs' (reverse-step) packet.
4149 set displaced-stepping
4150 show displaced-stepping
4151 Control displaced stepping mode. Displaced stepping is a way to
4152 single-step over breakpoints without removing them from the debuggee.
4153 Also known as "out-of-line single-stepping".
4156 show debug displaced
4157 Control display of debugging info for displaced stepping.
4159 maint set internal-error
4160 maint show internal-error
4161 Control what GDB does when an internal error is detected.
4163 maint set internal-warning
4164 maint show internal-warning
4165 Control what GDB does when an internal warning is detected.
4170 Use a wrapper program to launch programs for debugging.
4172 set multiple-symbols (all|ask|cancel)
4173 show multiple-symbols
4174 The value of this variable can be changed to adjust the debugger behavior
4175 when an expression or a breakpoint location contains an ambiguous symbol
4176 name (an overloaded function name, for instance).
4178 set breakpoint always-inserted
4179 show breakpoint always-inserted
4180 Keep breakpoints always inserted in the target, as opposed to inserting
4181 them when resuming the target, and removing them when the target stops.
4182 This option can improve debugger performance on slow remote targets.
4184 set arm fallback-mode (arm|thumb|auto)
4185 show arm fallback-mode
4186 set arm force-mode (arm|thumb|auto)
4188 These commands control how ARM GDB determines whether instructions
4189 are ARM or Thumb. The default for both settings is auto, which uses
4190 the current CPSR value for instructions without symbols; previous
4191 versions of GDB behaved as if "set arm fallback-mode arm".
4193 set disable-randomization
4194 show disable-randomization
4195 Standalone programs run with the virtual address space randomization enabled
4196 by default on some platforms. This option keeps the addresses stable across
4197 multiple debugging sessions.
4201 Control whether other threads are stopped or not when some thread hits
4206 Requests that asynchronous execution is enabled in the target, if available.
4207 In this case, it's possible to resume target in the background, and interact
4208 with GDB while the target is running. "show target-async" displays the
4209 current state of asynchronous execution of the target.
4211 set target-wide-charset
4212 show target-wide-charset
4213 The target-wide-charset is the name of the character set that GDB
4214 uses when printing characters whose type is wchar_t.
4216 set tcp auto-retry (on|off)
4218 set tcp connect-timeout
4219 show tcp connect-timeout
4220 These commands allow GDB to retry failed TCP connections to a remote stub
4221 with a specified timeout period; this is useful if the stub is launched
4222 in parallel with GDB but may not be ready to accept connections immediately.
4224 set libthread-db-search-path
4225 show libthread-db-search-path
4226 Control list of directories which GDB will search for appropriate
4229 set schedule-multiple (on|off)
4230 show schedule-multiple
4231 Allow GDB to resume all threads of all processes or only threads of
4232 the current process.
4236 Use more aggressive caching for accesses to the stack. This improves
4237 performance of remote debugging (particularly backtraces) without
4238 affecting correctness.
4240 set interactive-mode (on|off|auto)
4241 show interactive-mode
4242 Control whether GDB runs in interactive mode (on) or not (off).
4243 When in interactive mode, GDB waits for the user to answer all
4244 queries. Otherwise, GDB does not wait and assumes the default
4245 answer. When set to auto (the default), GDB determines which
4246 mode to use based on the stdin settings.
4251 For program forks, this is replaced by the new more generic `info
4252 inferiors' command. To list checkpoints, you can still use the
4253 `info checkpoints' command, which was an alias for the `info forks'
4257 Replaced by the new `inferior' command. To switch between
4258 checkpoints, you can still use the `restart' command, which was an
4259 alias for the `fork' command.
4262 This is removed, since some targets don't have a notion of
4263 processes. To switch between processes, you can still use the
4264 `inferior' command using GDB's own inferior number.
4267 For program forks, this is replaced by the new more generic `kill
4268 inferior' command. To delete a checkpoint, you can still use the
4269 `delete checkpoint' command, which was an alias for the `delete
4273 For program forks, this is replaced by the new more generic `detach
4274 inferior' command. To detach a checkpoint, you can still use the
4275 `detach checkpoint' command, which was an alias for the `detach
4278 * New native configurations
4280 x86/x86_64 Darwin i[34567]86-*-darwin*
4282 x86_64 MinGW x86_64-*-mingw*
4286 Lattice Mico32 lm32-*
4287 x86 DICOS i[34567]86-*-dicos*
4288 x86_64 DICOS x86_64-*-dicos*
4291 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4292 (mingw32ce) debugging.
4298 These commands were actually not implemented on any target.
4300 *** Changes in GDB 6.8
4302 * New native configurations
4304 NetBSD/hppa hppa*-*netbsd*
4305 Xtensa GNU/Linux xtensa*-*-linux*
4309 NetBSD/hppa hppa*-*-netbsd*
4310 Xtensa GNU/Lunux xtensa*-*-linux*
4312 * Change in command line behavior -- corefiles vs. process ids.
4314 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4315 attaching to process NUMBER fails, GDB no longer attempts to open a
4316 core file named NUMBER. Attaching to a program using the -c option
4317 is no longer supported. Instead, use the '-p' or '--pid' options.
4319 * GDB can now be built as a native debugger for debugging Windows x86
4320 (mingw32) Portable Executable (PE) programs.
4322 * Pending breakpoints no longer change their number when their address
4325 * GDB now supports breakpoints with multiple locations,
4326 including breakpoints on C++ constructors, inside C++ templates,
4327 and in inlined functions.
4329 * GDB's ability to debug optimized code has been improved. GDB more
4330 accurately identifies function bodies and lexical blocks that occupy
4331 more than one contiguous range of addresses.
4333 * Target descriptions can now describe registers for PowerPC.
4335 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4336 registers on PowerPC targets.
4338 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4339 targets even when the libthread_db library is not available.
4341 * The GDB remote stub, gdbserver, now supports the new file transfer
4342 commands (remote put, remote get, and remote delete).
4344 * The GDB remote stub, gdbserver, now supports run and attach in
4345 extended-remote mode.
4347 * hppa*64*-*-hpux11* target broken
4348 The debugger is unable to start a program and fails with the following
4349 error: "Error trying to get information about dynamic linker".
4350 The gdb-6.7 release is also affected.
4352 * GDB now supports the --enable-targets= configure option to allow
4353 building a single GDB executable that supports multiple remote
4354 target architectures.
4356 * GDB now supports debugging C and C++ programs which use the
4357 Decimal Floating Point extension. In addition, the PowerPC target
4358 now has a set of pseudo-registers to inspect decimal float values
4359 stored in two consecutive float registers.
4361 * The -break-insert MI command can optionally create pending
4364 * Improved support for debugging Ada
4365 Many improvements to the Ada language support have been made. These
4367 - Better support for Ada2005 interface types
4368 - Improved handling of arrays and slices in general
4369 - Better support for Taft-amendment types
4370 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4372 - Improved command completion in Ada
4375 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4380 set print frame-arguments (all|scalars|none)
4381 show print frame-arguments
4382 The value of this variable can be changed to control which argument
4383 values should be printed by the debugger when displaying a frame.
4388 Transfer files to and from a remote target, and delete remote files.
4395 Transfer files to and from a remote target, and delete remote files.
4397 * New remote packets
4404 Open, close, read, write, and delete files on the remote system.
4407 Attach to an existing process on the remote system, in extended-remote
4411 Run a new process on the remote system, in extended-remote mode.
4413 *** Changes in GDB 6.7
4415 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4416 bfd, libiberty and opcodes, as revealed by static analysis donated by
4417 Coverity, Inc. (http://scan.coverity.com).
4419 * When looking up multiply-defined global symbols, GDB will now prefer the
4420 symbol definition in the current shared library if it was built using the
4421 -Bsymbolic linker option.
4423 * When the Text User Interface (TUI) is not configured, GDB will now
4424 recognize the -tui command-line option and print a message that the TUI
4427 * The GDB remote stub, gdbserver, now has lower overhead for high
4428 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4430 * GDB for MIPS targets now autodetects whether a remote target provides
4431 32-bit or 64-bit register values.
4433 * Support for C++ member pointers has been improved.
4435 * GDB now understands XML target descriptions, which specify the
4436 target's overall architecture. GDB can read a description from
4437 a local file or over the remote serial protocol.
4439 * Vectors of single-byte data use a new integer type which is not
4440 automatically displayed as character or string data.
4442 * The /s format now works with the print command. It displays
4443 arrays of single-byte integers and pointers to single-byte integers
4446 * Target descriptions can now describe target-specific registers,
4447 for architectures which have implemented the support (currently
4448 only ARM, M68K, and MIPS).
4450 * GDB and the GDB remote stub, gdbserver, now support the XScale
4453 * The GDB remote stub, gdbserver, has been updated to support
4454 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4455 has been rewritten to use the standard GDB remote protocol.
4457 * GDB can now step into C++ functions which are called through thunks.
4459 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4461 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4462 layout. It also supports a TextSeg= and DataSeg= response when only
4463 segment base addresses (rather than offsets) are available.
4465 * The /i format now outputs any trailing branch delay slot instructions
4466 immediately following the last instruction within the count specified.
4468 * The GDB remote protocol "T" stop reply packet now supports a
4469 "library" response. Combined with the new "qXfer:libraries:read"
4470 packet, this response allows GDB to debug shared libraries on targets
4471 where the operating system manages the list of loaded libraries (e.g.
4472 Windows and SymbianOS).
4474 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4475 (DLLs) on Windows and Windows CE targets.
4477 * GDB now supports a faster verification that a .debug file matches its binary
4478 according to its build-id signature, if the signature is present.
4484 Enable or disable hardware flow control (RTS/CTS) on the serial port
4485 when debugging using remote targets.
4487 set mem inaccessible-by-default
4488 show mem inaccessible-by-default
4489 If the target supplies a memory map, for instance via the remote
4490 protocol's "qXfer:memory-map:read" packet, setting this variable
4491 prevents GDB from accessing memory outside the memory map. This
4492 is useful for targets with memory mapped registers or which react
4493 badly to accesses of unmapped address space.
4495 set breakpoint auto-hw
4496 show breakpoint auto-hw
4497 If the target supplies a memory map, for instance via the remote
4498 protocol's "qXfer:memory-map:read" packet, setting this variable
4499 lets GDB use hardware breakpoints automatically for memory regions
4500 where it can not use software breakpoints. This covers both the
4501 "break" command and internal breakpoints used for other commands
4502 including "next" and "finish".
4505 catch exception unhandled
4506 Stop the program execution when Ada exceptions are raised.
4509 Stop the program execution when an Ada assertion failed.
4513 Set an alternate system root for target files. This is a more
4514 general version of "set solib-absolute-prefix", which is now
4515 an alias to "set sysroot".
4518 Provide extended SPU facility status information. This set of
4519 commands is available only when debugging the Cell/B.E. SPU
4522 * New native configurations
4524 OpenBSD/sh sh*-*openbsd*
4527 unset tdesc filename
4529 Use the specified local file as an XML target description, and do
4530 not query the target for its built-in description.
4534 OpenBSD/sh sh*-*-openbsd*
4535 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4536 Toshiba Media Processor mep-elf
4538 * New remote packets
4541 Ignore the specified signals; pass them directly to the debugged program
4542 without stopping other threads or reporting them to GDB.
4544 qXfer:features:read:
4545 Read an XML target description from the target, which describes its
4550 Read or write contents of an spufs file on the target system. These
4551 packets are available only on the Cell/B.E. SPU architecture.
4553 qXfer:libraries:read:
4554 Report the loaded shared libraries. Combined with new "T" packet
4555 response, this packet allows GDB to debug shared libraries on
4556 targets where the operating system manages the list of loaded
4557 libraries (e.g. Windows and SymbianOS).
4561 Support for these obsolete configurations has been removed.
4569 i[34567]86-*-lynxos*
4570 i[34567]86-*-netware*
4571 i[34567]86-*-sco3.2v5*
4572 i[34567]86-*-sco3.2v4*
4574 i[34567]86-*-sysv4.2*
4577 i[34567]86-*-unixware2*
4578 i[34567]86-*-unixware*
4587 * Other removed features
4594 Various m68k-only ROM monitors.
4601 Various Renesas ROM monitors and debugging interfaces for SH and
4606 Support for a Macraigor serial interface to on-chip debugging.
4607 GDB does not directly support the newer parallel or USB
4612 A debug information format. The predecessor to DWARF 2 and
4613 DWARF 3, which are still supported.
4615 Support for the HP aCC compiler on HP-UX/PA-RISC
4617 SOM-encapsulated symbolic debugging information, automatic
4618 invocation of pxdb, and the aCC custom C++ ABI. This does not
4619 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4620 with aCC can still be debugged on an assembly level.
4622 MIPS ".pdr" sections
4624 A MIPS-specific format used to describe stack frame layout
4625 in debugging information.
4629 GDB could work with an older version of Guile to debug
4630 the interpreter and Scheme programs running in it.
4632 set mips stack-arg-size
4633 set mips saved-gpreg-size
4635 Use "set mips abi" to control parameter passing for MIPS.
4637 *** Changes in GDB 6.6
4642 Cell Broadband Engine SPU spu-elf
4644 * GDB can now be configured as a cross-debugger targeting native Windows
4645 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4646 running on a Windows system over TCP/IP to debug Windows programs.
4648 * The GDB remote stub, gdbserver, has been updated to support Windows and
4649 Cygwin debugging. Both single-threaded and multi-threaded programs are
4652 * The "set trust-readonly-sections" command works again. This command was
4653 broken in GDB 6.3, 6.4, and 6.5.
4655 * The "load" command now supports writing to flash memory, if the remote
4656 stub provides the required support.
4658 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4659 longer requires symbolic debug information (e.g. DWARF-2).
4664 unset substitute-path
4665 show substitute-path
4666 Manage a list of substitution rules that GDB uses to rewrite the name
4667 of the directories where the sources are located. This can be useful
4668 for instance when the sources were moved to a different location
4669 between compilation and debugging.
4673 Print each CLI command as it is executed. Each command is prefixed with
4674 a number of `+' symbols representing the nesting depth.
4675 The source command now has a `-v' option to enable the same feature.
4679 The ARM Demon monitor support (RDP protocol, "target rdp").
4681 Kernel Object Display, an embedded debugging feature which only worked with
4682 an obsolete version of Cisco IOS.
4684 The 'set download-write-size' and 'show download-write-size' commands.
4686 * New remote packets
4689 Tell a stub about GDB client features, and request remote target features.
4690 The first feature implemented is PacketSize, which allows the target to
4691 specify the size of packets it can handle - to minimize the number of
4692 packets required and improve performance when connected to a remote
4696 Fetch an OS auxilliary vector from the remote stub. This packet is a
4697 more efficient replacement for qPart:auxv:read.
4699 qXfer:memory-map:read:
4700 Fetch a memory map from the remote stub, including information about
4701 RAM, ROM, and flash memory devices.
4706 Erase and program a flash memory device.
4708 * Removed remote packets
4711 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4712 used it, and only gdbserver implemented it.
4714 *** Changes in GDB 6.5
4718 Renesas M32C/M16C m32c-elf
4720 Morpho Technologies ms1 ms1-elf
4724 init-if-undefined Initialize a convenience variable, but
4725 only if it doesn't already have a value.
4727 The following commands are presently only implemented for native GNU/Linux:
4729 checkpoint Save a snapshot of the program state.
4731 restart <n> Return the program state to a
4732 previously saved state.
4734 info checkpoints List currently saved checkpoints.
4736 delete-checkpoint <n> Delete a previously saved checkpoint.
4738 set|show detach-on-fork Tell gdb whether to detach from a newly
4739 forked process, or to keep debugging it.
4741 info forks List forks of the user program that
4742 are available to be debugged.
4744 fork <n> Switch to debugging one of several
4745 forks of the user program that are
4746 available to be debugged.
4748 delete-fork <n> Delete a fork from the list of forks
4749 that are available to be debugged (and
4750 kill the forked process).
4752 detach-fork <n> Delete a fork from the list of forks
4753 that are available to be debugged (and
4754 allow the process to continue).
4758 Morpho Technologies ms2 ms1-elf
4760 * Improved Windows host support
4762 GDB now builds as a cross debugger hosted on i686-mingw32, including
4763 native console support, and remote communications using either
4764 network sockets or serial ports.
4766 * Improved Modula-2 language support
4768 GDB can now print most types in the Modula-2 syntax. This includes:
4769 basic types, set types, record types, enumerated types, range types,
4770 pointer types and ARRAY types. Procedure var parameters are correctly
4771 printed and hexadecimal addresses and character constants are also
4772 written in the Modula-2 syntax. Best results can be obtained by using
4773 GNU Modula-2 together with the -gdwarf-2 command line option.
4777 The ARM rdi-share module.
4779 The Netware NLM debug server.
4781 *** Changes in GDB 6.4
4783 * New native configurations
4785 OpenBSD/arm arm*-*-openbsd*
4786 OpenBSD/mips64 mips64-*-openbsd*
4790 Morpho Technologies ms1 ms1-elf
4792 * New command line options
4794 --batch-silent As for --batch, but totally silent.
4795 --return-child-result The debugger will exist with the same value
4796 the child (debugged) program exited with.
4797 --eval-command COMMAND, -ex COMMAND
4798 Execute a single GDB CLI command. This may be
4799 specified multiple times and in conjunction
4800 with the --command (-x) option.
4802 * Deprecated commands removed
4804 The following commands, that were deprecated in 2000, have been
4808 set|show arm disassembly-flavor set|show arm disassembler
4809 othernames set arm disassembler
4810 set|show remotedebug set|show debug remote
4811 set|show archdebug set|show debug arch
4812 set|show eventdebug set|show debug event
4815 * New BSD user-level threads support
4817 It is now possible to debug programs using the user-level threads
4818 library on OpenBSD and FreeBSD. Currently supported (target)
4821 FreeBSD/amd64 x86_64-*-freebsd*
4822 FreeBSD/i386 i386-*-freebsd*
4823 OpenBSD/i386 i386-*-openbsd*
4825 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4826 are not yet supported.
4828 * New support for Matsushita MN10300 w/sim added
4829 (Work in progress). mn10300-elf.
4831 * REMOVED configurations and files
4833 VxWorks and the XDR protocol *-*-vxworks
4834 Motorola MCORE mcore-*-*
4835 National Semiconductor NS32000 ns32k-*-*
4837 * New "set print array-indexes" command
4839 After turning this setting "on", GDB prints the index of each element
4840 when displaying arrays. The default is "off" to preserve the previous
4843 * VAX floating point support
4845 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4847 * User-defined command support
4849 In addition to using $arg0..$arg9 for argument passing, it is now possible
4850 to use $argc to determine now many arguments have been passed. See the
4851 section on user-defined commands in the user manual for more information.
4853 *** Changes in GDB 6.3:
4855 * New command line option
4857 GDB now accepts -l followed by a number to set the timeout for remote
4860 * GDB works with GCC -feliminate-dwarf2-dups
4862 GDB now supports a more compact representation of DWARF-2 debug
4863 information using DW_FORM_ref_addr references. These are produced
4864 by GCC with the option -feliminate-dwarf2-dups and also by some
4865 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4866 to use -feliminate-dwarf2-dups.
4868 * Internationalization
4870 When supported by the host system, GDB will be built with
4871 internationalization (libintl). The task of marking up the sources is
4872 continued, we're looking forward to our first translation.
4876 Initial support for debugging programs compiled with the GNAT
4877 implementation of the Ada programming language has been integrated
4878 into GDB. In this release, support is limited to expression evaluation.
4880 * New native configurations
4882 GNU/Linux/m32r m32r-*-linux-gnu
4886 GDB's remote protocol now includes support for the 'p' packet. This
4887 packet is used to fetch individual registers from a remote inferior.
4889 * END-OF-LIFE registers[] compatibility module
4891 GDB's internal register infrastructure has been completely rewritten.
4892 The new infrastructure making possible the implementation of key new
4893 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4896 GDB 6.3 will be the last release to include the the registers[]
4897 compatibility module that allowed out-of-date configurations to
4898 continue to work. This change directly impacts the following
4908 powerpc bdm protocol
4910 Unless there is activity to revive these configurations, they will be
4911 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4913 * OBSOLETE configurations and files
4915 Configurations that have been declared obsolete in this release have
4916 been commented out. Unless there is activity to revive these
4917 configurations, the next release of GDB will have their sources
4918 permanently REMOVED.
4927 *** Changes in GDB 6.2.1:
4929 * MIPS `break main; run' gave an heuristic-fence-post warning
4931 When attempting to run even a simple program, a warning about
4932 heuristic-fence-post being hit would be reported. This problem has
4935 * MIPS IRIX 'long double' crashed GDB
4937 When examining a long double variable, GDB would get a segmentation
4938 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4939 IRIX long double values).
4943 A bug in the VAX stack code was causing problems with the "next"
4944 command. This problem has been fixed.
4946 *** Changes in GDB 6.2:
4948 * Fix for ``many threads''
4950 On GNU/Linux systems that use the NPTL threads library, a program
4951 rapidly creating and deleting threads would confuse GDB leading to the
4954 ptrace: No such process.
4955 thread_db_get_info: cannot get thread info: generic error
4957 This problem has been fixed.
4959 * "-async" and "-noasync" options removed.
4961 Support for the broken "-noasync" option has been removed (it caused
4964 * New ``start'' command.
4966 This command runs the program until the begining of the main procedure.
4968 * New BSD Kernel Data Access Library (libkvm) interface
4970 Using ``target kvm'' it is now possible to debug kernel core dumps and
4971 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4972 platforms. Currently supported (native-only) configurations are:
4974 FreeBSD/amd64 x86_64-*-freebsd*
4975 FreeBSD/i386 i?86-*-freebsd*
4976 NetBSD/i386 i?86-*-netbsd*
4977 NetBSD/m68k m68*-*-netbsd*
4978 NetBSD/sparc sparc-*-netbsd*
4979 OpenBSD/amd64 x86_64-*-openbsd*
4980 OpenBSD/i386 i?86-*-openbsd*
4981 OpenBSD/m68k m68*-openbsd*
4982 OpenBSD/sparc sparc-*-openbsd*
4984 * Signal trampoline code overhauled
4986 Many generic problems with GDB's signal handling code have been fixed.
4987 These include: backtraces through non-contiguous stacks; recognition
4988 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4989 call; backtrace through a signal trampoline; step into and out of
4990 signal handlers; and single-stepping in the signal trampoline.
4992 Please note that kernel bugs are a limiting factor here. These
4993 features have been shown to work on an s390 GNU/Linux system that
4994 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4996 * Cygwin support for DWARF 2 added.
4998 * New native configurations
5000 GNU/Linux/hppa hppa*-*-linux*
5001 OpenBSD/hppa hppa*-*-openbsd*
5002 OpenBSD/m68k m68*-*-openbsd*
5003 OpenBSD/m88k m88*-*-openbsd*
5004 OpenBSD/powerpc powerpc-*-openbsd*
5005 NetBSD/vax vax-*-netbsd*
5006 OpenBSD/vax vax-*-openbsd*
5008 * END-OF-LIFE frame compatibility module
5010 GDB's internal frame infrastructure has been completely rewritten.
5011 The new infrastructure making it possible to support key new features
5012 including DWARF 2 Call Frame Information. To aid in the task of
5013 migrating old configurations to this new infrastructure, a
5014 compatibility module, that allowed old configurations to continue to
5015 work, was also included.
5017 GDB 6.2 will be the last release to include this frame compatibility
5018 module. This change directly impacts the following configurations:
5028 Unless there is activity to revive these configurations, they will be
5029 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5031 * REMOVED configurations and files
5033 Sun 3, running SunOS 3 m68*-*-sunos3*
5034 Sun 3, running SunOS 4 m68*-*-sunos4*
5035 Sun 2, running SunOS 3 m68000-*-sunos3*
5036 Sun 2, running SunOS 4 m68000-*-sunos4*
5037 Motorola 680x0 running LynxOS m68*-*-lynxos*
5038 AT&T 3b1/Unix pc m68*-att-*
5039 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5040 decstation mips-dec-* mips-little-*
5041 riscos mips-*-riscos* mips-*-sysv*
5042 sonymips mips-sony-*
5043 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5045 *** Changes in GDB 6.1.1:
5047 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5049 The TUI (Text-mode User Interface) is now built as part of a default
5050 GDB configuration. It is enabled by either selecting the TUI with the
5051 command line option "-i=tui" or by running the separate "gdbtui"
5052 program. For more information on the TUI, see the manual "Debugging
5055 * Pending breakpoint support (also included in GDB 6.1)
5057 Support has been added to allow you to specify breakpoints in shared
5058 libraries that have not yet been loaded. If a breakpoint location
5059 cannot be found, and the "breakpoint pending" option is set to auto,
5060 GDB queries you if you wish to make the breakpoint pending on a future
5061 shared-library load. If and when GDB resolves the breakpoint symbol,
5062 the pending breakpoint is removed as one or more regular breakpoints
5065 Pending breakpoints are very useful for GCJ Java debugging.
5067 * Fixed ISO-C build problems
5069 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5070 non ISO-C code that stopped them being built using a more strict ISO-C
5071 compiler (e.g., IBM's C compiler).
5073 * Fixed build problem on IRIX 5
5075 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5076 wasn't able to compile compile on an IRIX 5 system.
5078 * Added execute permission to gdb/gdbserver/configure
5080 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5081 permission. This bug would cause configure to fail on a number of
5082 systems (Solaris, IRIX). Ref: server/519.
5084 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5086 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5087 has been updated to use constant array sizes.
5089 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5091 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5092 its generated DWARF Call Frame Info. This encoding was causing GDB to
5093 panic, that panic has been fixed. Ref: gdb/1628.
5095 * Fixed a problem when examining parameters in shared library code.
5097 When examining parameters in optimized shared library code generated
5098 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5099 not available''. GDB now correctly displays the variable's value.
5101 *** Changes in GDB 6.1:
5103 * Removed --with-mmalloc
5105 Support for the mmalloc memory manager has been removed, as it
5106 conflicted with the internal gdb byte cache.
5108 * Changes in AMD64 configurations
5110 The AMD64 target now includes the %cs and %ss registers. As a result
5111 the AMD64 remote protocol has changed; this affects the floating-point
5112 and SSE registers. If you rely on those registers for your debugging,
5113 you should upgrade gdbserver on the remote side.
5115 * Revised SPARC target
5117 The SPARC target has been completely revised, incorporating the
5118 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5119 support for LynxOS and SunOS 4 has been dropped. Calling functions
5120 from within GDB on operating systems with a non-executable stack
5121 (Solaris, OpenBSD) now works.
5125 GDB has a new C++ demangler which does a better job on the mangled
5126 names generated by current versions of g++. It also runs faster, so
5127 with this and other changes gdb should now start faster on large C++
5130 * DWARF 2 Location Expressions
5132 GDB support for location expressions has been extended to support function
5133 arguments and frame bases. Older versions of GDB could crash when they
5136 * C++ nested types and namespaces
5138 GDB's support for nested types and namespaces in C++ has been
5139 improved, especially if you use the DWARF 2 debugging format. (This
5140 is the default for recent versions of GCC on most platforms.)
5141 Specifically, if you have a class "Inner" defined within a class or
5142 namespace "Outer", then GDB realizes that the class's name is
5143 "Outer::Inner", not simply "Inner". This should greatly reduce the
5144 frequency of complaints about not finding RTTI symbols. In addition,
5145 if you are stopped at inside of a function defined within a namespace,
5146 GDB modifies its name lookup accordingly.
5148 * New native configurations
5150 NetBSD/amd64 x86_64-*-netbsd*
5151 OpenBSD/amd64 x86_64-*-openbsd*
5152 OpenBSD/alpha alpha*-*-openbsd*
5153 OpenBSD/sparc sparc-*-openbsd*
5154 OpenBSD/sparc64 sparc64-*-openbsd*
5156 * New debugging protocols
5158 M32R with SDI protocol m32r-*-elf*
5160 * "set prompt-escape-char" command deleted.
5162 The command "set prompt-escape-char" has been deleted. This command,
5163 and its very obscure effet on GDB's prompt, was never documented,
5164 tested, nor mentioned in the NEWS file.
5166 * OBSOLETE configurations and files
5168 Configurations that have been declared obsolete in this release have
5169 been commented out. Unless there is activity to revive these
5170 configurations, the next release of GDB will have their sources
5171 permanently REMOVED.
5173 Sun 3, running SunOS 3 m68*-*-sunos3*
5174 Sun 3, running SunOS 4 m68*-*-sunos4*
5175 Sun 2, running SunOS 3 m68000-*-sunos3*
5176 Sun 2, running SunOS 4 m68000-*-sunos4*
5177 Motorola 680x0 running LynxOS m68*-*-lynxos*
5178 AT&T 3b1/Unix pc m68*-att-*
5179 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5180 decstation mips-dec-* mips-little-*
5181 riscos mips-*-riscos* mips-*-sysv*
5182 sonymips mips-sony-*
5183 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5185 * REMOVED configurations and files
5187 SGI Irix-4.x mips-sgi-irix4 or iris4
5188 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5189 Z8000 simulator z8k-zilog-none or z8ksim
5190 Matsushita MN10200 w/simulator mn10200-*-*
5191 H8/500 simulator h8500-hitachi-hms or h8500hms
5192 HP/PA running BSD hppa*-*-bsd*
5193 HP/PA running OSF/1 hppa*-*-osf*
5194 HP/PA Pro target hppa*-*-pro*
5195 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5196 386BSD i[3456]86-*-bsd*
5197 Sequent family i[3456]86-sequent-sysv4*
5198 i[3456]86-sequent-sysv*
5199 i[3456]86-sequent-bsd*
5200 SPARC running LynxOS sparc-*-lynxos*
5201 SPARC running SunOS 4 sparc-*-sunos4*
5202 Tsqware Sparclet sparclet-*-*
5203 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5205 *** Changes in GDB 6.0:
5209 Support for debugging the Objective-C programming language has been
5210 integrated into GDB.
5212 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5214 DWARF 2's Call Frame Information makes available compiler generated
5215 information that more exactly describes the program's run-time stack.
5216 By using this information, GDB is able to provide more robust stack
5219 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5220 have been updated to use a new backtrace mechanism which includes
5221 DWARF 2 CFI support.
5225 GDB's remote protocol has been extended to include support for hosted
5226 file I/O (where the remote target uses GDB's file system). See GDB's
5227 remote protocol documentation for details.
5229 * All targets using the new architecture framework.
5231 All of GDB's targets have been updated to use the new internal
5232 architecture framework. The way is now open for future GDB releases
5233 to include cross-architecture native debugging support (i386 on amd64,
5236 * GNU/Linux's Thread Local Storage (TLS)
5238 GDB now includes support for for the GNU/Linux implementation of
5239 per-thread variables.
5241 * GNU/Linux's Native POSIX Thread Library (NPTL)
5243 GDB's thread code has been updated to work with either the new
5244 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5246 * Separate debug info.
5248 GDB, in conjunction with BINUTILS, now supports a mechanism for
5249 automatically loading debug information from a separate file. Instead
5250 of shipping full debug and non-debug versions of system libraries,
5251 system integrators can now instead ship just the stripped libraries
5252 and optional debug files.
5254 * DWARF 2 Location Expressions
5256 DWARF 2 Location Expressions allow the compiler to more completely
5257 describe the location of variables (even in optimized code) to the
5260 GDB now includes preliminary support for location expressions (support
5261 for DW_OP_piece is still missing).
5265 A number of long standing bugs that caused GDB to die while starting a
5266 Java application have been fixed. GDB's Java support is now
5267 considered "useable".
5269 * GNU/Linux support for fork, vfork, and exec.
5271 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5272 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5275 * GDB supports logging output to a file
5277 There are two new commands, "set logging" and "show logging", which can be
5278 used to capture GDB's output to a file.
5280 * The meaning of "detach" has changed for gdbserver
5282 The "detach" command will now resume the application, as documented. To
5283 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5286 * d10v, m68hc11 `regs' command deprecated
5288 The `info registers' command has been updated so that it displays the
5289 registers using a format identical to the old `regs' command.
5293 A new command, "maint set profile on/off", has been added. This command can
5294 be used to enable or disable profiling while running GDB, to profile a
5295 session or a set of commands. In addition there is a new configure switch,
5296 "--enable-profiling", which will cause GDB to be compiled with profiling
5297 data, for more informative profiling results.
5299 * Default MI syntax changed to "mi2".
5301 The default MI (machine interface) syntax, enabled by the command line
5302 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5303 "mi1", can be enabled by specifying the option "-i=mi1".
5305 Support for the original "mi0" syntax (included in GDB 5.0) has been
5308 Fix for gdb/192: removed extraneous space when displaying frame level.
5309 Fix for gdb/672: update changelist is now output in mi list format.
5310 Fix for gdb/702: a -var-assign that updates the value now shows up
5311 in a subsequent -var-update.
5313 * New native configurations.
5315 FreeBSD/amd64 x86_64-*-freebsd*
5317 * Multi-arched targets.
5319 HP/PA HPUX11 hppa*-*-hpux*
5320 Renesas M32R/D w/simulator m32r-*-elf*
5322 * OBSOLETE configurations and files
5324 Configurations that have been declared obsolete in this release have
5325 been commented out. Unless there is activity to revive these
5326 configurations, the next release of GDB will have their sources
5327 permanently REMOVED.
5329 Z8000 simulator z8k-zilog-none or z8ksim
5330 Matsushita MN10200 w/simulator mn10200-*-*
5331 H8/500 simulator h8500-hitachi-hms or h8500hms
5332 HP/PA running BSD hppa*-*-bsd*
5333 HP/PA running OSF/1 hppa*-*-osf*
5334 HP/PA Pro target hppa*-*-pro*
5335 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5336 Sequent family i[3456]86-sequent-sysv4*
5337 i[3456]86-sequent-sysv*
5338 i[3456]86-sequent-bsd*
5339 Tsqware Sparclet sparclet-*-*
5340 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5342 * REMOVED configurations and files
5345 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5346 IBM AIX PS/2 i[3456]86-*-aix
5347 i386 running Mach 3.0 i[3456]86-*-mach3*
5348 i386 running Mach i[3456]86-*-mach*
5349 i386 running OSF/1 i[3456]86-*osf1mk*
5350 HP/Apollo 68k Family m68*-apollo*-sysv*,
5352 m68*-hp-bsd*, m68*-hp-hpux*
5353 Argonaut Risc Chip (ARC) arc-*-*
5354 Mitsubishi D30V d30v-*-*
5355 Fujitsu FR30 fr30-*-elf*
5356 OS/9000 i[34]86-*-os9k
5357 I960 with MON960 i960-*-coff
5359 * MIPS $fp behavior changed
5361 The convenience variable $fp, for the MIPS, now consistently returns
5362 the address of the current frame's base. Previously, depending on the
5363 context, $fp could refer to either $sp or the current frame's base
5364 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5365 The GNU Source-Level Debugger''.
5367 *** Changes in GDB 5.3:
5369 * GNU/Linux shared library multi-threaded performance improved.
5371 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5372 `/proc', in preference to `ptrace' for memory reads. This may result
5373 in an improvement in the start-up time of multi-threaded, shared
5374 library applications when run under GDB. One GDB user writes: ``loads
5375 shared libs like mad''.
5377 * ``gdbserver'' now supports multi-threaded applications on some targets
5379 Support for debugging multi-threaded applications which use
5380 the GNU/Linux LinuxThreads package has been added for
5381 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5382 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5384 * GDB now supports C/C++ preprocessor macros.
5386 GDB now expands preprocessor macro invocations in C/C++ expressions,
5387 and provides various commands for showing macro definitions and how
5390 The new command `macro expand EXPRESSION' expands any macro
5391 invocations in expression, and shows the result.
5393 The new command `show macro MACRO-NAME' shows the definition of the
5394 macro named MACRO-NAME, and where it was defined.
5396 Most compilers don't include information about macros in the debugging
5397 information by default. In GCC 3.1, for example, you need to compile
5398 your program with the options `-gdwarf-2 -g3'. If the macro
5399 information is present in the executable, GDB will read it.
5401 * Multi-arched targets.
5403 DEC Alpha (partial) alpha*-*-*
5404 DEC VAX (partial) vax-*-*
5406 National Semiconductor NS32000 (partial) ns32k-*-*
5407 Motorola 68000 (partial) m68k-*-*
5408 Motorola MCORE mcore-*-*
5412 Fujitsu FRV architecture added by Red Hat frv*-*-*
5415 * New native configurations
5417 Alpha NetBSD alpha*-*-netbsd*
5418 SH NetBSD sh*-*-netbsdelf*
5419 MIPS NetBSD mips*-*-netbsd*
5420 UltraSPARC NetBSD sparc64-*-netbsd*
5422 * OBSOLETE configurations and files
5424 Configurations that have been declared obsolete in this release have
5425 been commented out. Unless there is activity to revive these
5426 configurations, the next release of GDB will have their sources
5427 permanently REMOVED.
5429 Mitsubishi D30V d30v-*-*
5430 OS/9000 i[34]86-*-os9k
5431 IBM AIX PS/2 i[3456]86-*-aix
5432 Fujitsu FR30 fr30-*-elf*
5433 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5434 Argonaut Risc Chip (ARC) arc-*-*
5435 i386 running Mach 3.0 i[3456]86-*-mach3*
5436 i386 running Mach i[3456]86-*-mach*
5437 i386 running OSF/1 i[3456]86-*osf1mk*
5438 HP/Apollo 68k Family m68*-apollo*-sysv*,
5440 m68*-hp-bsd*, m68*-hp-hpux*
5441 I960 with MON960 i960-*-coff
5443 * OBSOLETE languages
5445 CHILL, a Pascal like language used by telecommunications companies.
5447 * REMOVED configurations and files
5449 AMD 29k family via UDI a29k-amd-udi, udi29k
5450 A29K VxWorks a29k-*-vxworks
5451 AMD 29000 embedded, using EBMON a29k-none-none
5452 AMD 29000 embedded with COFF a29k-none-coff
5453 AMD 29000 embedded with a.out a29k-none-aout
5455 testsuite/gdb.hp/gdb.threads-hp/ directory
5457 * New command "set max-user-call-depth <nnn>"
5459 This command allows the user to limit the call depth of user-defined
5460 commands. The default is 1024.
5462 * Changes in FreeBSD/i386 native debugging.
5464 Support for the "generate-core-file" has been added.
5466 * New commands "dump", "append", and "restore".
5468 These commands allow data to be copied from target memory
5469 to a bfd-format or binary file (dump and append), and back
5470 from a file into memory (restore).
5472 * Improved "next/step" support on multi-processor Alpha Tru64.
5474 The previous single-step mechanism could cause unpredictable problems,
5475 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5476 of a software single-step mechanism prevents this.
5478 *** Changes in GDB 5.2.1:
5486 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5487 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5488 Fix, by Joel Brobecker imported from mainline.
5490 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5491 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5492 Fix, by Fred Fish, imported from mainline.
5494 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5495 Surprisingly enough, it works now.
5496 By Michal Ludvig, imported from mainline.
5498 i386 hardware watchpoint support:
5499 avoid misses on second run for some targets.
5500 By Pierre Muller, imported from mainline.
5502 *** Changes in GDB 5.2:
5504 * New command "set trust-readonly-sections on[off]".
5506 This command is a hint that tells gdb that read-only sections
5507 really are read-only (ie. that their contents will not change).
5508 In this mode, gdb will go to the object file rather than the
5509 target to read memory from read-only sections (such as ".text").
5510 This can be a significant performance improvement on some
5511 (notably embedded) targets.
5513 * New command "generate-core-file" (or "gcore").
5515 This new gdb command allows the user to drop a core file of the child
5516 process state at any time. So far it's been implemented only for
5517 GNU/Linux and Solaris, but should be relatively easily ported to other
5518 hosts. Argument is core file name (defaults to core.<pid>).
5520 * New command line option
5522 GDB now accepts --pid or -p followed by a process id.
5524 * Change in command line behavior -- corefiles vs. process ids.
5526 There is a subtle behavior in the way in which GDB handles
5527 command line arguments. The first non-flag argument is always
5528 a program to debug, but the second non-flag argument may either
5529 be a corefile or a process id. Previously, GDB would attempt to
5530 open the second argument as a corefile, and if that failed, would
5531 issue a superfluous error message and then attempt to attach it as
5532 a process. Now, if the second argument begins with a non-digit,
5533 it will be treated as a corefile. If it begins with a digit,
5534 GDB will attempt to attach it as a process, and if no such process
5535 is found, will then attempt to open it as a corefile.
5537 * Changes in ARM configurations.
5539 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5540 configuration is fully multi-arch.
5542 * New native configurations
5544 ARM NetBSD arm*-*-netbsd*
5545 x86 OpenBSD i[3456]86-*-openbsd*
5546 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5547 Sparc64 running FreeBSD sparc64-*-freebsd*
5551 Sanyo XStormy16 xstormy16-elf
5553 * OBSOLETE configurations and files
5555 Configurations that have been declared obsolete in this release have
5556 been commented out. Unless there is activity to revive these
5557 configurations, the next release of GDB will have their sources
5558 permanently REMOVED.
5560 AMD 29k family via UDI a29k-amd-udi, udi29k
5561 A29K VxWorks a29k-*-vxworks
5562 AMD 29000 embedded, using EBMON a29k-none-none
5563 AMD 29000 embedded with COFF a29k-none-coff
5564 AMD 29000 embedded with a.out a29k-none-aout
5566 testsuite/gdb.hp/gdb.threads-hp/ directory
5568 * REMOVED configurations and files
5570 TI TMS320C80 tic80-*-*
5572 PowerPC Solaris powerpcle-*-solaris*
5573 PowerPC Windows NT powerpcle-*-cygwin32
5574 PowerPC Netware powerpc-*-netware*
5575 Harris/CXUX m88k m88*-harris-cxux*
5576 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5577 ns32k-utek-sysv* ns32k-utek-*
5578 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5579 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5580 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5581 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5582 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5584 * Changes to command line processing
5586 The new `--args' feature can be used to specify command-line arguments
5587 for the inferior from gdb's command line.
5589 * Changes to key bindings
5591 There is a new `operate-and-get-next' function bound to `C-o'.
5593 *** Changes in GDB 5.1.1
5595 Fix compile problem on DJGPP.
5597 Fix a problem with floating-point registers on the i386 being
5600 Fix to stop GDB crashing on .debug_str debug info.
5602 Numerous documentation fixes.
5604 Numerous testsuite fixes.
5606 *** Changes in GDB 5.1:
5608 * New native configurations
5610 Alpha FreeBSD alpha*-*-freebsd*
5611 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5612 MIPS GNU/Linux mips*-*-linux*
5613 MIPS SGI Irix 6.x mips*-sgi-irix6*
5614 ia64 AIX ia64-*-aix*
5615 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5619 Motorola 68HC11 and 68HC12 m68hc11-elf
5621 UltraSparc running GNU/Linux sparc64-*-linux*
5623 * OBSOLETE configurations and files
5625 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5626 Harris/CXUX m88k m88*-harris-cxux*
5627 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5628 ns32k-utek-sysv* ns32k-utek-*
5629 TI TMS320C80 tic80-*-*
5631 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5632 PowerPC Solaris powerpcle-*-solaris*
5633 PowerPC Windows NT powerpcle-*-cygwin32
5634 PowerPC Netware powerpc-*-netware*
5635 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5636 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5637 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5638 Apple Macintosh (MPW) host N/A
5640 stuff.c (Program to stuff files into a specially prepared space in kdb)
5641 kdb-start.c (Main loop for the standalone kernel debugger)
5643 Configurations that have been declared obsolete in this release have
5644 been commented out. Unless there is activity to revive these
5645 configurations, the next release of GDB will have their sources
5646 permanently REMOVED.
5648 * REMOVED configurations and files
5650 Altos 3068 m68*-altos-*
5651 Convex c1-*-*, c2-*-*
5653 ARM RISCix arm-*-* (as host)
5657 * GDB has been converted to ISO C.
5659 GDB's source code has been converted to ISO C. In particular, the
5660 sources are fully protoized, and rely on standard headers being
5665 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5667 * The MI enabled by default.
5669 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5670 revised and enabled by default. Packages which use GDB as a debugging
5671 engine behind a UI or another front end are encouraged to switch to
5672 using the GDB/MI interface, instead of the old annotations interface
5673 which is now deprecated.
5675 * Support for debugging Pascal programs.
5677 GDB now includes support for debugging Pascal programs. The following
5678 main features are supported:
5680 - Pascal-specific data types such as sets;
5682 - automatic recognition of Pascal sources based on file-name
5685 - Pascal-style display of data types, variables, and functions;
5687 - a Pascal expression parser.
5689 However, some important features are not yet supported.
5691 - Pascal string operations are not supported at all;
5693 - there are some problems with boolean types;
5695 - Pascal type hexadecimal constants are not supported
5696 because they conflict with the internal variables format;
5698 - support for Pascal objects and classes is not full yet;
5700 - unlike Pascal, GDB is case-sensitive for symbol names.
5702 * Changes in completion.
5704 Commands such as `shell', `run' and `set args', which pass arguments
5705 to inferior programs, now complete on file names, similar to what
5706 users expect at the shell prompt.
5708 Commands which accept locations, such as `disassemble', `print',
5709 `breakpoint', `until', etc. now complete on filenames as well as
5710 program symbols. Thus, if you type "break foob TAB", and the source
5711 files linked into the programs include `foobar.c', that file name will
5712 be one of the candidates for completion. However, file names are not
5713 considered for completion after you typed a colon that delimits a file
5714 name from a name of a function in that file, as in "break foo.c:bar".
5716 `set demangle-style' completes on available demangling styles.
5718 * New platform-independent commands:
5720 It is now possible to define a post-hook for a command as well as a
5721 hook that runs before the command. For more details, see the
5722 documentation of `hookpost' in the GDB manual.
5724 * Changes in GNU/Linux native debugging.
5726 Support for debugging multi-threaded programs has been completely
5727 revised for all platforms except m68k and sparc. You can now debug as
5728 many threads as your system allows you to have.
5730 Attach/detach is supported for multi-threaded programs.
5732 Support for SSE registers was added for x86. This doesn't work for
5733 multi-threaded programs though.
5735 * Changes in MIPS configurations.
5737 Multi-arch support is enabled for all MIPS configurations.
5739 GDB can now be built as native debugger on SGI Irix 6.x systems for
5740 debugging n32 executables. (Debugging 64-bit executables is not yet
5743 * Unified support for hardware watchpoints in all x86 configurations.
5745 Most (if not all) native x86 configurations support hardware-assisted
5746 breakpoints and watchpoints in a unified manner. This support
5747 implements debug register sharing between watchpoints, which allows to
5748 put a virtually infinite number of watchpoints on the same address,
5749 and also supports watching regions up to 16 bytes with several debug
5752 The new maintenance command `maintenance show-debug-regs' toggles
5753 debugging print-outs in functions that insert, remove, and test
5754 watchpoints and hardware breakpoints.
5756 * Changes in the DJGPP native configuration.
5758 New command ``info dos sysinfo'' displays assorted information about
5759 the CPU, OS, memory, and DPMI server.
5761 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5762 display information about segment descriptors stored in GDT, LDT, and
5765 New commands ``info dos pde'' and ``info dos pte'' display entries
5766 from Page Directory and Page Tables (for now works with CWSDPMI only).
5767 New command ``info dos address-pte'' displays the Page Table entry for
5768 a given linear address.
5770 GDB can now pass command lines longer than 126 characters to the
5771 program being debugged (requires an update to the libdbg.a library
5772 which is part of the DJGPP development kit).
5774 DWARF2 debug info is now supported.
5776 It is now possible to `step' and `next' through calls to `longjmp'.
5778 * Changes in documentation.
5780 All GDB documentation was converted to GFDL, the GNU Free
5781 Documentation License.
5783 Tracepoints-related commands are now fully documented in the GDB
5786 TUI, the Text-mode User Interface, is now documented in the manual.
5788 Tracepoints-related commands are now fully documented in the GDB
5791 The "GDB Internals" manual now has an index. It also includes
5792 documentation of `ui_out' functions, GDB coding standards, x86
5793 hardware watchpoints, and memory region attributes.
5795 * GDB's version number moved to ``version.in''
5797 The Makefile variable VERSION has been replaced by the file
5798 ``version.in''. People creating GDB distributions should update the
5799 contents of this file.
5803 GUD support is now a standard part of the EMACS distribution.
5805 *** Changes in GDB 5.0:
5807 * Improved support for debugging FP programs on x86 targets
5809 Unified and much-improved support for debugging floating-point
5810 programs on all x86 targets. In particular, ``info float'' now
5811 displays the FP registers in the same format on all x86 targets, with
5812 greater level of detail.
5814 * Improvements and bugfixes in hardware-assisted watchpoints
5816 It is now possible to watch array elements, struct members, and
5817 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5818 on x86 targets no longer erroneously trigger when the address is
5821 * Improvements in the native DJGPP version of GDB
5823 The distribution now includes all the scripts and auxiliary files
5824 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5825 machines ``out of the box''.
5827 The DJGPP version can now debug programs that use signals. It is
5828 possible to catch signals that happened in the debuggee, deliver
5829 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5830 would kill the program being debugged.) Programs that hook hardware
5831 interrupts (keyboard, timer, etc.) can also be debugged.
5833 It is now possible to debug DJGPP programs that redirect their
5834 standard handles or switch them to raw (as opposed to cooked) mode, or
5835 even close them. The command ``run < foo > bar'' works as expected,
5836 and ``info terminal'' reports useful information about the debuggee's
5837 terminal, including raw/cooked mode, redirection, etc.
5839 The DJGPP version now uses termios functions for console I/O, which
5840 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5843 DOS-style file names with drive letters are now fully supported by
5846 It is now possible to debug DJGPP programs that switch their working
5847 directory. It is also possible to rerun the debuggee any number of
5848 times without restarting GDB; thus, you can use the same setup,
5849 breakpoints, etc. for many debugging sessions.
5851 * New native configurations
5853 ARM GNU/Linux arm*-*-linux*
5854 PowerPC GNU/Linux powerpc-*-linux*
5858 Motorola MCore mcore-*-*
5859 x86 VxWorks i[3456]86-*-vxworks*
5860 PowerPC VxWorks powerpc-*-vxworks*
5861 TI TMS320C80 tic80-*-*
5863 * OBSOLETE configurations
5865 Altos 3068 m68*-altos-*
5866 Convex c1-*-*, c2-*-*
5868 ARM RISCix arm-*-* (as host)
5871 Configurations that have been declared obsolete will be commented out,
5872 but the code will be left in place. If there is no activity to revive
5873 these configurations before the next release of GDB, the sources will
5874 be permanently REMOVED.
5876 * Gould support removed
5878 Support for the Gould PowerNode and NP1 has been removed.
5880 * New features for SVR4
5882 On SVR4 native platforms (such as Solaris), if you attach to a process
5883 without first loading a symbol file, GDB will now attempt to locate and
5884 load symbols from the running process's executable file.
5886 * Many C++ enhancements
5888 C++ support has been greatly improved. Overload resolution now works properly
5889 in almost all cases. RTTI support is on the way.
5891 * Remote targets can connect to a sub-program
5893 A popen(3) style serial-device has been added. This device starts a
5894 sub-process (such as a stand-alone simulator) and then communicates
5895 with that. The sub-program to run is specified using the syntax
5896 ``|<program> <args>'' vis:
5898 (gdb) set remotedebug 1
5899 (gdb) target extended-remote |mn10300-elf-sim program-args
5901 * MIPS 64 remote protocol
5903 A long standing bug in the mips64 remote protocol where by GDB
5904 expected certain 32 bit registers (ex SR) to be transfered as 32
5905 instead of 64 bits has been fixed.
5907 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5908 added to provide backward compatibility with older versions of GDB.
5910 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5912 The command ``set remotebinarydownload'' command has been replaced by
5913 ``set remote X-packet''. Other commands in ``set remote'' family
5914 include ``set remote P-packet''.
5916 * Breakpoint commands accept ranges.
5918 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5919 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5920 ``tracepoint passcount'' also accepts a range of tracepoints.
5922 * ``apropos'' command added.
5924 The ``apropos'' command searches through command names and
5925 documentation strings, printing out matches, making it much easier to
5926 try to find a command that does what you are looking for.
5930 A new machine oriented interface (MI) has been added to GDB. This
5931 interface is designed for debug environments running GDB as a separate
5932 process. This is part of the long term libGDB project. See the
5933 "GDB/MI" chapter of the GDB manual for further information. It can be
5934 enabled by configuring with:
5936 .../configure --enable-gdbmi
5938 *** Changes in GDB-4.18:
5940 * New native configurations
5942 HP-UX 10.20 hppa*-*-hpux10.20
5943 HP-UX 11.x hppa*-*-hpux11.0*
5944 M68K GNU/Linux m68*-*-linux*
5948 Fujitsu FR30 fr30-*-elf*
5949 Intel StrongARM strongarm-*-*
5950 Mitsubishi D30V d30v-*-*
5952 * OBSOLETE configurations
5954 Gould PowerNode, NP1 np1-*-*, pn-*-*
5956 Configurations that have been declared obsolete will be commented out,
5957 but the code will be left in place. If there is no activity to revive
5958 these configurations before the next release of GDB, the sources will
5959 be permanently REMOVED.
5963 As a compatibility experiment, GDB's source files buildsym.h and
5964 buildsym.c have been converted to pure standard C, no longer
5965 containing any K&R compatibility code. We believe that all systems in
5966 use today either come with a standard C compiler, or have a GCC port
5967 available. If this is not true, please report the affected
5968 configuration to bug-gdb@gnu.org immediately. See the README file for
5969 information about getting a standard C compiler if you don't have one
5974 GDB now uses readline 2.2.
5976 * set extension-language
5978 You can now control the mapping between filename extensions and source
5979 languages by using the `set extension-language' command. For instance,
5980 you can ask GDB to treat .c files as C++ by saying
5981 set extension-language .c c++
5982 The command `info extensions' lists all of the recognized extensions
5983 and their associated languages.
5985 * Setting processor type for PowerPC and RS/6000
5987 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5988 you can use the `set processor' command to specify what variant of the
5989 PowerPC family you are debugging. The command
5993 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5994 following PowerPC and RS6000 variants:
5996 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5997 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5999 403GC IBM PowerPC 403GC
6000 505 Motorola PowerPC 505
6001 860 Motorola PowerPC 860 or 850
6002 601 Motorola PowerPC 601
6003 602 Motorola PowerPC 602
6004 603 Motorola/IBM PowerPC 603 or 603e
6005 604 Motorola PowerPC 604 or 604e
6006 750 Motorola/IBM PowerPC 750 or 750
6008 At the moment, this command just tells GDB what to name the
6009 special-purpose processor registers. Since almost all the affected
6010 registers are inaccessible to user-level programs, this command is
6011 only useful for remote debugging in its present form.
6015 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6016 more extensive support for HP-UX. Added features include shared
6017 library support, kernel threads and hardware watchpoints for 11.00,
6018 support for HP's ANSI C and C++ compilers, and a compatibility mode
6019 for xdb and dbx commands.
6023 HP's donation includes the new concept of catchpoints, which is a
6024 generalization of the old catch command. On HP-UX, it is now possible
6025 to catch exec, fork, and vfork, as well as library loading.
6027 This means that the existing catch command has changed; its first
6028 argument now specifies the type of catch to be set up. See the
6029 output of "help catch" for a list of catchpoint types.
6031 * Debugging across forks
6033 On HP-UX, you can choose which process to debug when a fork() happens
6038 HP has donated a curses-based terminal user interface (TUI). To get
6039 it, build with --enable-tui. Although this can be enabled for any
6040 configuration, at present it only works for native HP debugging.
6042 * GDB remote protocol additions
6044 A new protocol packet 'X' that writes binary data is now available.
6045 Default behavior is to try 'X', then drop back to 'M' if the stub
6046 fails to respond. The settable variable `remotebinarydownload'
6047 allows explicit control over the use of 'X'.
6049 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6050 full 64-bit address. The command
6052 set remoteaddresssize 32
6054 can be used to revert to the old behaviour. For existing remote stubs
6055 the change should not be noticed, as the additional address information
6058 In order to assist in debugging stubs, you may use the maintenance
6059 command `packet' to send any text string to the stub. For instance,
6061 maint packet heythere
6063 sends the packet "$heythere#<checksum>". Note that it is very easy to
6064 disrupt a debugging session by sending the wrong packet at the wrong
6067 The compare-sections command allows you to compare section data on the
6068 target to what is in the executable file without uploading or
6069 downloading, by comparing CRC checksums.
6071 * Tracing can collect general expressions
6073 You may now collect general expressions at tracepoints. This requires
6074 further additions to the target-side stub; see tracepoint.c and
6075 doc/agentexpr.texi for further details.
6077 * mask-address variable for Mips
6079 For Mips targets, you may control the zeroing of the upper 32 bits of
6080 a 64-bit address by entering `set mask-address on'. This is mainly
6081 of interest to users of embedded R4xxx and R5xxx processors.
6083 * Higher serial baud rates
6085 GDB's serial code now allows you to specify baud rates 57600, 115200,
6086 230400, and 460800 baud. (Note that your host system may not be able
6087 to achieve all of these rates.)
6091 The i960 configuration now includes an initial implementation of a
6092 builtin simulator, contributed by Jim Wilson.
6095 *** Changes in GDB-4.17:
6097 * New native configurations
6099 Alpha GNU/Linux alpha*-*-linux*
6100 Unixware 2.x i[3456]86-unixware2*
6101 Irix 6.x mips*-sgi-irix6*
6102 PowerPC GNU/Linux powerpc-*-linux*
6103 PowerPC Solaris powerpcle-*-solaris*
6104 Sparc GNU/Linux sparc-*-linux*
6105 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6109 Argonaut Risc Chip (ARC) arc-*-*
6110 Hitachi H8/300S h8300*-*-*
6111 Matsushita MN10200 w/simulator mn10200-*-*
6112 Matsushita MN10300 w/simulator mn10300-*-*
6113 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6114 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6115 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6116 Mitsubishi D10V w/simulator d10v-*-*
6117 Mitsubishi M32R/D w/simulator m32r-*-elf*
6118 Tsqware Sparclet sparclet-*-*
6119 NEC V850 w/simulator v850-*-*
6121 * New debugging protocols
6123 ARM with RDI protocol arm*-*-*
6124 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6125 DDB and LSI variants of PMON protocol mips*-*-*
6126 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6127 PowerPC with SDS protocol powerpc{,le}-*-eabi
6128 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6132 All configurations can now understand and use the DWARF 2 debugging
6133 format. The choice is automatic, if the symbol file contains DWARF 2
6138 GDB now includes basic Java language support. This support is
6139 only useful with Java compilers that produce native machine code.
6141 * solib-absolute-prefix and solib-search-path
6143 For SunOS and SVR4 shared libraries, you may now set the prefix for
6144 loading absolute shared library symbol files, and the search path for
6145 locating non-absolute shared library symbol files.
6147 * Live range splitting
6149 GDB can now effectively debug code for which GCC has performed live
6150 range splitting as part of its optimization. See gdb/doc/LRS for
6151 more details on the expected format of the stabs information.
6155 GDB's support for the GNU Hurd, including thread debugging, has been
6156 updated to work with current versions of the Hurd.
6160 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6161 instruction set. ARM GDB automatically detects when Thumb
6162 instructions are in use, and adjusts disassembly and backtracing
6167 GDB's MIPS target configurations now handle the MIP16 16-bit
6172 GDB now includes support for overlays; if an executable has been
6173 linked such that multiple sections are based at the same address, GDB
6174 will decide which section to use for symbolic info. You can choose to
6175 control the decision manually, using overlay commands, or implement
6176 additional target-side support and use "overlay load-target" to bring
6177 in the overlay mapping. Do "help overlay" for more detail.
6181 The command "info symbol <address>" displays information about
6182 the symbol at the specified address.
6186 The standard remote protocol now includes an extension that allows
6187 asynchronous collection and display of trace data. This requires
6188 extensive support in the target-side debugging stub. Tracing mode
6189 includes a new interaction mode in GDB and new commands: see the
6190 file tracepoint.c for more details.
6194 Configurations for embedded MIPS now include a simulator contributed
6195 by Cygnus Solutions. The simulator supports the instruction sets
6196 of most MIPS variants.
6200 Sparc configurations may now include the ERC32 simulator contributed
6201 by the European Space Agency. The simulator is not built into
6202 Sparc targets by default; configure with --enable-sim to include it.
6206 For target configurations that may include multiple variants of a
6207 basic architecture (such as MIPS and SH), you may now set the
6208 architecture explicitly. "set arch" sets, "info arch" lists
6209 the possible architectures.
6211 *** Changes in GDB-4.16:
6213 * New native configurations
6215 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6216 M68K NetBSD m68k-*-netbsd*
6217 PowerPC AIX 4.x powerpc-*-aix*
6218 PowerPC MacOS powerpc-*-macos*
6219 PowerPC Windows NT powerpcle-*-cygwin32
6220 RS/6000 AIX 4.x rs6000-*-aix4*
6224 ARM with RDP protocol arm-*-*
6225 I960 with MON960 i960-*-coff
6226 MIPS VxWorks mips*-*-vxworks*
6227 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6228 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6230 Matra Sparclet sparclet-*-*
6234 The powerpc-eabi configuration now includes the PSIM simulator,
6235 contributed by Andrew Cagney, with assistance from Mike Meissner.
6236 PSIM is a very elaborate model of the PowerPC, including not only
6237 basic instruction set execution, but also details of execution unit
6238 performance and I/O hardware. See sim/ppc/README for more details.
6242 GDB now works with Solaris 2.5.
6244 * Windows 95/NT native
6246 GDB will now work as a native debugger on Windows 95 and Windows NT.
6247 To build it from source, you must use the "gnu-win32" environment,
6248 which uses a DLL to emulate enough of Unix to run the GNU tools.
6249 Further information, binaries, and sources are available at
6250 ftp.cygnus.com, under pub/gnu-win32.
6252 * dont-repeat command
6254 If a user-defined command includes the command `dont-repeat', then the
6255 command will not be repeated if the user just types return. This is
6256 useful if the command is time-consuming to run, so that accidental
6257 extra keystrokes don't run the same command many times.
6259 * Send break instead of ^C
6261 The standard remote protocol now includes an option to send a break
6262 rather than a ^C to the target in order to interrupt it. By default,
6263 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6265 * Remote protocol timeout
6267 The standard remote protocol includes a new variable `remotetimeout'
6268 that allows you to set the number of seconds before GDB gives up trying
6269 to read from the target. The default value is 2.
6271 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6273 By default GDB will automatically keep track of objects as they are
6274 loaded and unloaded by the dynamic linker. By using the command `set
6275 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6276 when shared library events occur, thus allowing you to set breakpoints
6277 in shared libraries which are explicitly loaded by the inferior.
6279 Note this feature does not work on hpux8. On hpux9 you must link
6280 /usr/lib/end.o into your program. This feature should work
6281 automatically on hpux10.
6283 * Irix 5.x hardware watchpoint support
6285 Irix 5 configurations now support the use of hardware watchpoints.
6287 * Mips protocol "SYN garbage limit"
6289 When debugging a Mips target using the `target mips' protocol, you
6290 may set the number of characters that GDB will ignore by setting
6291 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6292 every character. The default value is 1050.
6294 * Recording and replaying remote debug sessions
6296 If you set `remotelogfile' to the name of a file, gdb will write to it
6297 a recording of a remote debug session. This recording may then be
6298 replayed back to gdb using "gdbreplay". See gdbserver/README for
6299 details. This is useful when you have a problem with GDB while doing
6300 remote debugging; you can make a recording of the session and send it
6301 to someone else, who can then recreate the problem.
6303 * Speedups for remote debugging
6305 GDB includes speedups for downloading and stepping MIPS systems using
6306 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6307 and more efficient S-record downloading.
6309 * Memory use reductions and statistics collection
6311 GDB now uses less memory and reports statistics about memory usage.
6312 Try the `maint print statistics' command, for example.
6314 *** Changes in GDB-4.15:
6316 * Psymtabs for XCOFF
6318 The symbol reader for AIX GDB now uses partial symbol tables. This
6319 can greatly improve startup time, especially for large executables.
6321 * Remote targets use caching
6323 Remote targets now use a data cache to speed up communication with the
6324 remote side. The data cache could lead to incorrect results because
6325 it doesn't know about volatile variables, thus making it impossible to
6326 debug targets which use memory mapped I/O devices. `set remotecache
6327 off' turns the the data cache off.
6329 * Remote targets may have threads
6331 The standard remote protocol now includes support for multiple threads
6332 in the target system, using new protocol commands 'H' and 'T'. See
6333 gdb/remote.c for details.
6337 If GDB is configured with `--enable-netrom', then it will include
6338 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6339 acts as though it is a bank of ROM on the target board, but you can
6340 write into it over the network. GDB's support consists only of
6341 support for fast loading into the emulated ROM; to debug, you must use
6342 another protocol, such as standard remote protocol. The usual
6343 sequence is something like
6345 target nrom <netrom-hostname>
6347 target remote <netrom-hostname>:1235
6351 GDB now includes support for the Apple Macintosh, as a host only. It
6352 may be run as either an MPW tool or as a standalone application, and
6353 it can debug through the serial port. All the usual GDB commands are
6354 available, but to the target command, you must supply "serial" as the
6355 device type instead of "/dev/ttyXX". See mpw-README in the main
6356 directory for more information on how to build. The MPW configuration
6357 scripts */mpw-config.in support only a few targets, and only the
6358 mips-idt-ecoff target has been tested.
6362 GDB configuration now uses autoconf. This is not user-visible,
6363 but does simplify configuration and building.
6367 GDB now supports hpux10.
6369 *** Changes in GDB-4.14:
6371 * New native configurations
6373 x86 FreeBSD i[345]86-*-freebsd
6374 x86 NetBSD i[345]86-*-netbsd
6375 NS32k NetBSD ns32k-*-netbsd
6376 Sparc NetBSD sparc-*-netbsd
6380 A29K VxWorks a29k-*-vxworks
6381 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6382 CPU32 EST-300 emulator m68*-*-est*
6383 PowerPC ELF powerpc-*-elf
6386 * Alpha OSF/1 support for procfs
6388 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6389 possible to attach to running processes. As the mounting of the /proc
6390 filesystem is optional on the Alpha, GDB automatically determines
6391 the availability of /proc during startup. This can lead to problems
6392 if /proc is unmounted after GDB has been started.
6394 * Arguments to user-defined commands
6396 User commands may accept up to 10 arguments separated by whitespace.
6397 Arguments are accessed within the user command via $arg0..$arg9. A
6400 print $arg0 + $arg1 + $arg2
6402 To execute the command use:
6405 Defines the command "adder" which prints the sum of its three arguments.
6406 Note the arguments are text substitutions, so they may reference variables,
6407 use complex expressions, or even perform inferior function calls.
6409 * New `if' and `while' commands
6411 This makes it possible to write more sophisticated user-defined
6412 commands. Both commands take a single argument, which is the
6413 expression to evaluate, and must be followed by the commands to
6414 execute, one per line, if the expression is nonzero, the list being
6415 terminated by the word `end'. The `if' command list may include an
6416 `else' word, which causes the following commands to be executed only
6417 if the expression is zero.
6419 * Fortran source language mode
6421 GDB now includes partial support for Fortran 77. It will recognize
6422 Fortran programs and can evaluate a subset of Fortran expressions, but
6423 variables and functions may not be handled correctly. GDB will work
6424 with G77, but does not yet know much about symbols emitted by other
6427 * Better HPUX support
6429 Most debugging facilities now work on dynamic executables for HPPAs
6430 running hpux9 or later. You can attach to running dynamically linked
6431 processes, but by default the dynamic libraries will be read-only, so
6432 for instance you won't be able to put breakpoints in them. To change
6433 that behavior do the following before running the program:
6439 This will cause the libraries to be mapped private and read-write.
6440 To revert to the normal behavior, do this:
6446 You cannot set breakpoints or examine data in the library until after
6447 the library is loaded if the function/data symbols do not have
6450 GDB can now also read debug symbols produced by the HP C compiler on
6451 HPPAs (sorry, no C++, Fortran or 68k support).
6453 * Target byte order now dynamically selectable
6455 You can choose which byte order to use with a target system, via the
6456 commands "set endian big" and "set endian little", and you can see the
6457 current setting by using "show endian". You can also give the command
6458 "set endian auto", in which case GDB will use the byte order
6459 associated with the executable. Currently, only embedded MIPS
6460 configurations support dynamic selection of target byte order.
6462 * New DOS host serial code
6464 This version uses DPMI interrupts to handle buffered I/O, so you
6465 no longer need to run asynctsr when debugging boards connected to
6468 *** Changes in GDB-4.13:
6470 * New "complete" command
6472 This lists all the possible completions for the rest of the line, if it
6473 were to be given as a command itself. This is intended for use by emacs.
6475 * Trailing space optional in prompt
6477 "set prompt" no longer adds a space for you after the prompt you set. This
6478 allows you to set a prompt which ends in a space or one that does not.
6480 * Breakpoint hit counts
6482 "info break" now displays a count of the number of times the breakpoint
6483 has been hit. This is especially useful in conjunction with "ignore"; you
6484 can ignore a large number of breakpoint hits, look at the breakpoint info
6485 to see how many times the breakpoint was hit, then run again, ignoring one
6486 less than that number, and this will get you quickly to the last hit of
6489 * Ability to stop printing at NULL character
6491 "set print null-stop" will cause GDB to stop printing the characters of
6492 an array when the first NULL is encountered. This is useful when large
6493 arrays actually contain only short strings.
6495 * Shared library breakpoints
6497 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6498 breakpoints in shared libraries before the executable is run.
6500 * Hardware watchpoints
6502 There is a new hardware breakpoint for the watch command for sparclite
6503 targets. See gdb/sparclite/hw_breakpoint.note.
6505 Hardware watchpoints are also now supported under GNU/Linux.
6509 Annotations have been added. These are for use with graphical interfaces,
6510 and are still experimental. Currently only gdba.el uses these.
6512 * Improved Irix 5 support
6514 GDB now works properly with Irix 5.2.
6516 * Improved HPPA support
6518 GDB now works properly with the latest GCC and GAS.
6520 * New native configurations
6522 Sequent PTX4 i[34]86-sequent-ptx4
6523 HPPA running OSF/1 hppa*-*-osf*
6524 Atari TT running SVR4 m68*-*-sysv4*
6525 RS/6000 LynxOS rs6000-*-lynxos*
6529 OS/9000 i[34]86-*-os9k
6530 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6533 * Hitachi SH7000 and E7000-PC ICE support
6535 There is now support for communicating with the Hitachi E7000-PC ICE.
6536 This is available automatically when GDB is configured for the SH.
6540 As usual, a variety of small fixes and improvements, both generic
6541 and configuration-specific. See the ChangeLog for more detail.
6543 *** Changes in GDB-4.12:
6545 * Irix 5 is now supported
6549 GDB-4.12 on the HPPA has a number of changes which make it unable
6550 to debug the output from the currently released versions of GCC and
6551 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6552 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6553 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6556 *** Changes in GDB-4.11:
6558 * User visible changes:
6562 The "set remotedebug" option is now consistent between the mips remote
6563 target, remote targets using the gdb-specific protocol, UDI (AMD's
6564 debug protocol for the 29k) and the 88k bug monitor. It is now an
6565 integer specifying a debug level (normally 0 or 1, but 2 means more
6566 debugging info for the mips target).
6568 * DEC Alpha native support
6570 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6571 debug info, but GDB works fairly well with the DEC compiler and should
6572 work with a future GCC release. See the README file for a few
6573 Alpha-specific notes.
6575 * Preliminary thread implementation
6577 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6579 * LynxOS native and target support for 386
6581 This release has been hosted on LynxOS 2.2, and also can be configured
6582 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6585 * Improvements in C++ mangling/demangling.
6587 This release has much better g++ debugging, specifically in name
6588 mangling/demangling, virtual function calls, print virtual table,
6589 call methods, ...etc.
6591 *** Changes in GDB-4.10:
6593 * User visible changes:
6595 Remote debugging using the GDB-specific (`target remote') protocol now
6596 supports the `load' command. This is only useful if you have some
6597 other way of getting the stub to the target system, and you can put it
6598 somewhere in memory where it won't get clobbered by the download.
6600 Filename completion now works.
6602 When run under emacs mode, the "info line" command now causes the
6603 arrow to point to the line specified. Also, "info line" prints
6604 addresses in symbolic form (as well as hex).
6606 All vxworks based targets now support a user settable option, called
6607 vxworks-timeout. This option represents the number of seconds gdb
6608 should wait for responses to rpc's. You might want to use this if
6609 your vxworks target is, perhaps, a slow software simulator or happens
6610 to be on the far side of a thin network line.
6614 This release contains support for using a DEC alpha as a GDB host for
6615 cross debugging. Native alpha debugging is not supported yet.
6618 *** Changes in GDB-4.9:
6622 This is the first GDB release which is accompanied by a matching testsuite.
6623 The testsuite requires installation of dejagnu, which should be available
6624 via ftp from most sites that carry GNU software.
6628 'Cfront' style demangling has had its name changed to 'ARM' style, to
6629 emphasize that it was written from the specifications in the C++ Annotated
6630 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6631 disclaimers, it still generated too much confusion with users attempting to
6632 use gdb with AT&T cfront.
6636 GDB now uses a standard remote interface to a simulator library.
6637 So far, the library contains simulators for the Zilog Z8001/2, the
6638 Hitachi H8/300, H8/500 and Super-H.
6640 * New targets supported
6642 H8/300 simulator h8300-hitachi-hms or h8300hms
6643 H8/500 simulator h8500-hitachi-hms or h8500hms
6644 SH simulator sh-hitachi-hms or sh
6645 Z8000 simulator z8k-zilog-none or z8ksim
6646 IDT MIPS board over serial line mips-idt-ecoff
6648 Cross-debugging to GO32 targets is supported. It requires a custom
6649 version of the i386-stub.c module which is integrated with the
6650 GO32 memory extender.
6652 * New remote protocols
6654 MIPS remote debugging protocol.
6656 * New source languages supported
6658 This version includes preliminary support for Chill, a Pascal like language
6659 used by telecommunications companies. Chill support is also being integrated
6660 into the GNU compiler, but we don't know when it will be publically available.
6663 *** Changes in GDB-4.8:
6665 * HP Precision Architecture supported
6667 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6668 version of this support was available as a set of patches from the
6669 University of Utah. GDB does not support debugging of programs
6670 compiled with the HP compiler, because HP will not document their file
6671 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6672 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6674 Many problems in the preliminary version have been fixed.
6676 * Faster and better demangling
6678 We have improved template demangling and fixed numerous bugs in the GNU style
6679 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6680 character types (wchar_t) are now supported. Demangling of each symbol is now
6681 only done once, and is cached when the symbol table for a file is read in.
6682 This results in a small increase in memory usage for C programs, a moderate
6683 increase in memory usage for C++ programs, and a fantastic speedup in
6686 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6687 from the specifications in the Annotated Reference Manual, which AT&T's
6688 compiler does not actually implement.
6690 * G++ multiple inheritance compiler problem
6692 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6693 inheritance lattices was reworked to properly discover ambiguities. We
6694 recently found an example which causes this new algorithm to fail in a
6695 very subtle way, producing bad debug information for those classes.
6696 The file 'gcc.patch' (in this directory) can be applied to gcc to
6697 circumvent the problem. A future GCC release will contain a complete
6700 The previous G++ debug info problem (mentioned below for the gdb-4.7
6701 release) is fixed in gcc version 2.3.2.
6703 * Improved configure script
6705 The `configure' script will now attempt to guess your system type if
6706 you don't supply a host system type. The old scheme of supplying a
6707 host system triplet is preferable over using this. All the magic is
6708 done in the new `config.guess' script. Examine it for details.
6710 We have also brought our configure script much more in line with the FSF's
6711 version. It now supports the --with-xxx options. In particular,
6712 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6713 The resulting GDB will not be able to read arbitrary object file formats --
6714 only the format ``expected'' to be used on the configured target system.
6715 We hope to make this the default in a future release.
6717 * Documentation improvements
6719 There's new internal documentation on how to modify GDB, and how to
6720 produce clean changes to the code. We implore people to read it
6721 before submitting changes.
6723 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6724 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6725 `info' files are also provided. To build `info' files from scratch,
6726 you will need the latest `makeinfo' release, which will be available in
6727 a future texinfo-X.Y release.
6729 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6730 We're not sure exactly which versions have this problem, but it has
6731 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6732 or better. If that isn't possible, there is a patch in
6733 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6734 around this problem.
6738 GDB now supports array constants that can be used in expressions typed in by
6739 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6740 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6743 The new directory `gdb/sparclite' contains a program that demonstrates
6744 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6746 * New native hosts supported
6748 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6749 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6751 * New targets supported
6753 AMD 29k family via UDI a29k-amd-udi or udi29k
6755 * New file formats supported
6757 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6758 HPUX core files, and SCO 3.2v2 core files.
6762 Attaching to processes now works again; thanks for the many bug reports.
6764 We have also stomped on a bunch of core dumps caused by
6765 printf_filtered("%s") problems.
6767 We eliminated a copyright problem on the rpc and ptrace header files
6768 for VxWorks, which was discovered at the last minute during the 4.7
6769 release. You should now be able to build a VxWorks GDB.
6771 You can now interrupt gdb while an attached process is running. This
6772 will cause the attached process to stop, and give control back to GDB.
6774 We fixed problems caused by using too many file descriptors
6775 for reading symbols from object files and libraries. This was
6776 especially a problem for programs that used many (~100) shared
6779 The `step' command now only enters a subroutine if there is line number
6780 information for the subroutine. Otherwise it acts like the `next'
6781 command. Previously, `step' would enter subroutines if there was
6782 any debugging information about the routine. This avoids problems
6783 when using `cc -g1' on MIPS machines.
6785 * Internal improvements
6787 GDB's internal interfaces have been improved to make it easier to support
6788 debugging of multiple languages in the future.
6790 GDB now uses a common structure for symbol information internally.
6791 Minimal symbols (derived from linkage symbols in object files), partial
6792 symbols (from a quick scan of debug information), and full symbols
6793 contain a common subset of information, making it easier to write
6794 shared code that handles any of them.
6796 * New command line options
6798 We now accept --silent as an alias for --quiet.
6802 The memory-mapped-malloc library is now licensed under the GNU Library
6803 General Public License.
6805 *** Changes in GDB-4.7:
6807 * Host/native/target split
6809 GDB has had some major internal surgery to untangle the support for
6810 hosts and remote targets. Now, when you configure GDB for a remote
6811 target, it will no longer load in all of the support for debugging
6812 local programs on the host. When fully completed and tested, this will
6813 ensure that arbitrary host/target combinations are possible.
6815 The primary conceptual shift is to separate the non-portable code in
6816 GDB into three categories. Host specific code is required any time GDB
6817 is compiled on that host, regardless of the target. Target specific
6818 code relates to the peculiarities of the target, but can be compiled on
6819 any host. Native specific code is everything else: it can only be
6820 built when the host and target are the same system. Child process
6821 handling and core file support are two common `native' examples.
6823 GDB's use of /proc for controlling Unix child processes is now cleaner.
6824 It has been split out into a single module under the `target_ops' vector,
6825 plus two native-dependent functions for each system that uses /proc.
6827 * New hosts supported
6829 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6830 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6831 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6833 * New targets supported
6835 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6836 68030 and CPU32 m68030-*-*, m68332-*-*
6838 * New native hosts supported
6840 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6841 (386bsd is not well tested yet)
6842 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6844 * New file formats supported
6846 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6847 supports reading of `a.out.adobe' object files, which are an a.out
6848 format extended with minimal information about multiple sections.
6852 `show copying' is the same as the old `info copying'.
6853 `show warranty' is the same as `info warrantee'.
6854 These were renamed for consistency. The old commands continue to work.
6856 `info handle' is a new alias for `info signals'.
6858 You can now define pre-command hooks, which attach arbitrary command
6859 scripts to any command. The commands in the hook will be executed
6860 prior to the user's command. You can also create a hook which will be
6861 executed whenever the program stops. See gdb.texinfo.
6865 We now deal with Cfront style name mangling, and can even extract type
6866 info from mangled symbols. GDB can automatically figure out which
6867 symbol mangling style your C++ compiler uses.
6869 Calling of methods and virtual functions has been improved as well.
6873 The crash that occured when debugging Sun Ansi-C compiled binaries is
6874 fixed. This was due to mishandling of the extra N_SO stabs output
6877 We also finally got Ultrix 4.2 running in house, and fixed core file
6878 support, with help from a dozen people on the net.
6880 John M. Farrell discovered that the reason that single-stepping was so
6881 slow on all of the Mips based platforms (primarily SGI and DEC) was
6882 that we were trying to demangle and lookup a symbol used for internal
6883 purposes on every instruction that was being stepped through. Changing
6884 the name of that symbol so that it couldn't be mistaken for a C++
6885 mangled symbol sped things up a great deal.
6887 Rich Pixley sped up symbol lookups in general by getting much smarter
6888 about when C++ symbol mangling is necessary. This should make symbol
6889 completion (TAB on the command line) much faster. It's not as fast as
6890 we'd like, but it's significantly faster than gdb-4.6.
6894 A new user controllable variable 'call_scratch_address' can
6895 specify the location of a scratch area to be used when GDB
6896 calls a function in the target. This is necessary because the
6897 usual method of putting the scratch area on the stack does not work
6898 in systems that have separate instruction and data spaces.
6900 We integrated changes to support the 29k UDI (Universal Debugger
6901 Interface), but discovered at the last minute that we didn't have all
6902 of the appropriate copyright paperwork. We are working with AMD to
6903 resolve this, and hope to have it available soon.
6907 We have sped up the remote serial line protocol, especially for targets
6908 with lots of registers. It now supports a new `expedited status' ('T')
6909 message which can be used in place of the existing 'S' status message.
6910 This allows the remote stub to send only the registers that GDB
6911 needs to make a quick decision about single-stepping or conditional
6912 breakpoints, eliminating the need to fetch the entire register set for
6913 each instruction being stepped through.
6915 The GDB remote serial protocol now implements a write-through cache for
6916 registers, only re-reading the registers if the target has run.
6918 There is also a new remote serial stub for SPARC processors. You can
6919 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6920 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6921 processor with a serial port.
6925 Configure.in files have become much easier to read and modify. A new
6926 `table driven' format makes it more obvious what configurations are
6927 supported, and what files each one uses.
6931 There is a new opcodes library which will eventually contain all of the
6932 disassembly routines and opcode tables. At present, it only contains
6933 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6934 disassembler (binutils/objdump) to share these routines.
6936 The libiberty library is now copylefted under the GNU Library General
6937 Public License. This allows more liberal use, and was done so libg++
6938 can use it. This makes no difference to GDB, since the Library License
6939 grants all the rights from the General Public License.
6943 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6944 reference to the stabs symbol info used by the debugger. It is (as far
6945 as we know) the only published document on this fascinating topic. We
6946 encourage you to read it, compare it to the stabs information on your
6947 system, and send improvements on the document in general (to
6948 bug-gdb@prep.ai.mit.edu).
6950 And, of course, many bugs have been fixed.
6953 *** Changes in GDB-4.6:
6955 * Better support for C++ function names
6957 GDB now accepts as input the "demangled form" of C++ overloaded function
6958 names and member function names, and can do command completion on such names
6959 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6960 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6961 Make use of command completion, it is your friend.
6963 GDB also now accepts a variety of C++ mangled symbol formats. They are
6964 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6965 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6966 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6967 for the list of formats.
6969 * G++ symbol mangling problem
6971 Recent versions of gcc have a bug in how they emit debugging information for
6972 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6973 directory) can be applied to gcc to fix the problem. Alternatively, if you
6974 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6975 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6976 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6979 * New 'maintenance' command
6981 All of the commands related to hacking GDB internals have been moved out of
6982 the main command set, and now live behind the 'maintenance' command. This
6983 can also be abbreviated as 'mt'. The following changes were made:
6985 dump-me -> maintenance dump-me
6986 info all-breakpoints -> maintenance info breakpoints
6987 printmsyms -> maintenance print msyms
6988 printobjfiles -> maintenance print objfiles
6989 printpsyms -> maintenance print psymbols
6990 printsyms -> maintenance print symbols
6992 The following commands are new:
6994 maintenance demangle Call internal GDB demangler routine to
6995 demangle a C++ link name and prints the result.
6996 maintenance print type Print a type chain for a given symbol
6998 * Change to .gdbinit file processing
7000 We now read the $HOME/.gdbinit file before processing the argv arguments
7001 (e.g. reading symbol files or core files). This allows global parameters to
7002 be set, which will apply during the symbol reading. The ./.gdbinit is still
7003 read after argv processing.
7005 * New hosts supported
7007 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7009 GNU/Linux support i386-unknown-linux or linux
7011 We are also including code to support the HP/PA running BSD and HPUX. This
7012 is almost guaranteed not to work, as we didn't have time to test or build it
7013 for this release. We are including it so that the more adventurous (or
7014 masochistic) of you can play with it. We also had major problems with the
7015 fact that the compiler that we got from HP doesn't support the -g option.
7018 * New targets supported
7020 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7022 * More smarts about finding #include files
7024 GDB now remembers the compilation directory for all include files, and for
7025 all files from which C is generated (like yacc and lex sources). This
7026 greatly improves GDB's ability to find yacc/lex sources, and include files,
7027 especially if you are debugging your program from a directory different from
7028 the one that contains your sources.
7030 We also fixed a bug which caused difficulty with listing and setting
7031 breakpoints in include files which contain C code. (In the past, you had to
7032 try twice in order to list an include file that you hadn't looked at before.)
7034 * Interesting infernals change
7036 GDB now deals with arbitrary numbers of sections, where the symbols for each
7037 section must be relocated relative to that section's landing place in the
7038 target's address space. This work was needed to support ELF with embedded
7039 stabs used by Solaris-2.0.
7041 * Bug fixes (of course!)
7043 There have been loads of fixes for the following things:
7044 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7045 i960, stabs, DOS(GO32), procfs, etc...
7047 See the ChangeLog for details.
7049 *** Changes in GDB-4.5:
7051 * New machines supported (host and target)
7053 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7055 SGI Irix-4.x mips-sgi-irix4 or iris4
7057 * New malloc package
7059 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7060 Mmalloc is capable of handling mutiple heaps of memory. It is also
7061 capable of saving a heap to a file, and then mapping it back in later.
7062 This can be used to greatly speedup the startup of GDB by using a
7063 pre-parsed symbol table which lives in a mmalloc managed heap. For
7064 more details, please read mmalloc/mmalloc.texi.
7068 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7069 'help info proc' for details.
7071 * MIPS ecoff symbol table format
7073 The code that reads MIPS symbol table format is now supported on all hosts.
7074 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7077 * File name changes for MS-DOS
7079 Many files in the config directories have been renamed to make it easier to
7080 support GDB on MS-DOSe systems (which have very restrictive file name
7081 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7082 environment) is close to working but has some remaining problems. Note
7083 that debugging of DOS programs is not supported, due to limitations
7084 in the ``operating system'', but it can be used to host cross-debugging.
7086 * Cross byte order fixes
7088 Many fixes have been made to support cross debugging of Sparc and MIPS
7089 targets from hosts whose byte order differs.
7091 * New -mapped and -readnow options
7093 If memory-mapped files are available on your system through the 'mmap'
7094 system call, you can use the -mapped option on the `file' or
7095 `symbol-file' commands to cause GDB to write the symbols from your
7096 program into a reusable file. If the program you are debugging is
7097 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7098 Future GDB debugging sessions will notice the presence of this file,
7099 and will quickly map in symbol information from it, rather than reading
7100 the symbol table from the executable program. Using the '-mapped'
7101 option in a GDB `file' or `symbol-file' command has the same effect as
7102 starting GDB with the '-mapped' command-line option.
7104 You can cause GDB to read the entire symbol table immediately by using
7105 the '-readnow' option with any of the commands that load symbol table
7106 information (or on the GDB command line). This makes the command
7107 slower, but makes future operations faster.
7109 The -mapped and -readnow options are typically combined in order to
7110 build a `fred.syms' file that contains complete symbol information.
7111 A simple GDB invocation to do nothing but build a `.syms' file for future
7114 gdb -batch -nx -mapped -readnow programname
7116 The `.syms' file is specific to the host machine on which GDB is run.
7117 It holds an exact image of GDB's internal symbol table. It cannot be
7118 shared across multiple host platforms.
7120 * longjmp() handling
7122 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7123 siglongjmp() without losing control. This feature has not yet been ported to
7124 all systems. It currently works on many 386 platforms, all MIPS-based
7125 platforms (SGI, DECstation, etc), and Sun3/4.
7129 Preliminary work has been put in to support the new Solaris OS from Sun. At
7130 this time, it can control and debug processes, but it is not capable of
7135 As always, many many bug fixes. The major areas were with g++, and mipsread.
7136 People using the MIPS-based platforms should experience fewer mysterious
7137 crashes and trashed symbol tables.
7139 *** Changes in GDB-4.4:
7141 * New machines supported (host and target)
7143 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7145 BSD Reno on Vax vax-dec-bsd
7146 Ultrix on Vax vax-dec-ultrix
7148 * New machines supported (target)
7150 AMD 29000 embedded, using EBMON a29k-none-none
7154 GDB continues to improve its handling of C++. `References' work better.
7155 The demangler has also been improved, and now deals with symbols mangled as
7156 per the Annotated C++ Reference Guide.
7158 GDB also now handles `stabs' symbol information embedded in MIPS
7159 `ecoff' symbol tables. Since the ecoff format was not easily
7160 extensible to handle new languages such as C++, this appeared to be a
7161 good way to put C++ debugging info into MIPS binaries. This option
7162 will be supported in the GNU C compiler, version 2, when it is
7165 * New features for SVR4
7167 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7168 shared libraries. Debugging dynamically linked programs should present
7169 only minor differences from debugging statically linked programs.
7171 The `info proc' command will print out information about any process
7172 on an SVR4 system (including the one you are debugging). At the moment,
7173 it prints the address mappings of the process.
7175 If you bring up GDB on another SVR4 system, please send mail to
7176 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7178 * Better dynamic linking support in SunOS
7180 Reading symbols from shared libraries which contain debugging symbols
7181 now works properly. However, there remain issues such as automatic
7182 skipping of `transfer vector' code during function calls, which
7183 make it harder to debug code in a shared library, than to debug the
7184 same code linked statically.
7188 GDB is now using the latest `getopt' routines from the FSF. This
7189 version accepts the -- prefix for options with long names. GDB will
7190 continue to accept the old forms (-option and +option) as well.
7191 Various single letter abbreviations for options have been explicity
7192 added to the option table so that they won't get overshadowed in the
7193 future by other options that begin with the same letter.
7197 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7198 Many assorted bugs have been handled. Many more remain to be handled.
7199 See the various ChangeLog files (primarily in gdb and bfd) for details.
7202 *** Changes in GDB-4.3:
7204 * New machines supported (host and target)
7206 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7207 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7208 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7210 * Almost SCO Unix support
7212 We had hoped to support:
7213 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7214 (except for core file support), but we discovered very late in the release
7215 that it has problems with process groups that render gdb unusable. Sorry
7216 about that. I encourage people to fix it and post the fixes.
7218 * Preliminary ELF and DWARF support
7220 GDB can read ELF object files on System V Release 4, and can handle
7221 debugging records for C, in DWARF format, in ELF files. This support
7222 is preliminary. If you bring up GDB on another SVR4 system, please
7223 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7228 GDB now uses the latest `readline' library. One user-visible change
7229 is that two tabs will list possible command completions, which previously
7230 required typing M-? (meta-question mark, or ESC ?).
7234 The `stepi' bug that many of you noticed has been squashed.
7235 Many bugs in C++ have been handled. Many more remain to be handled.
7236 See the various ChangeLog files (primarily in gdb and bfd) for details.
7238 * State of the MIPS world (in case you wondered):
7240 GDB can understand the symbol tables emitted by the compilers
7241 supplied by most vendors of MIPS-based machines, including DEC. These
7242 symbol tables are in a format that essentially nobody else uses.
7244 Some versions of gcc come with an assembler post-processor called
7245 mips-tfile. This program is required if you want to do source-level
7246 debugging of gcc-compiled programs. I believe FSF does not ship
7247 mips-tfile with gcc version 1, but it will eventually come with gcc
7250 Debugging of g++ output remains a problem. g++ version 1.xx does not
7251 really support it at all. (If you're lucky, you should be able to get
7252 line numbers and stack traces to work, but no parameters or local
7253 variables.) With some work it should be possible to improve the
7256 When gcc version 2 is released, you will have somewhat better luck.
7257 However, even then you will get confusing results for inheritance and
7260 We will eventually provide full debugging of g++ output on
7261 DECstations. This will probably involve some kind of stabs-in-ecoff
7262 encapulation, but the details have not been worked out yet.
7265 *** Changes in GDB-4.2:
7267 * Improved configuration
7269 Only one copy of `configure' exists now, and it is not self-modifying.
7270 Porting BFD is simpler.
7274 The `step' and `next' commands now only stop at the first instruction
7275 of a source line. This prevents the multiple stops that used to occur
7276 in switch statements, for-loops, etc. `Step' continues to stop if a
7277 function that has debugging information is called within the line.
7281 Lots of small bugs fixed. More remain.
7283 * New host supported (not target)
7285 Intel 386 PC clone running Mach i386-none-mach
7288 *** Changes in GDB-4.1:
7290 * Multiple source language support
7292 GDB now has internal scaffolding to handle several source languages.
7293 It determines the type of each source file from its filename extension,
7294 and will switch expression parsing and number formatting to match the
7295 language of the function in the currently selected stack frame.
7296 You can also specifically set the language to be used, with
7297 `set language c' or `set language modula-2'.
7301 GDB now has preliminary support for the GNU Modula-2 compiler,
7302 currently under development at the State University of New York at
7303 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7304 continue through the fall of 1991 and into 1992.
7306 Other Modula-2 compilers are currently not supported, and attempting to
7307 debug programs compiled with them will likely result in an error as the
7308 symbol table is read. Feel free to work on it, though!
7310 There are hooks in GDB for strict type checking and range checking,
7311 in the `Modula-2 philosophy', but they do not currently work.
7315 GDB can now write to executable and core files (e.g. patch
7316 a variable's value). You must turn this switch on, specify
7317 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7318 by assigning a new value to a variable. Modifications take
7321 * Automatic SunOS shared library reading
7323 When you run your program, GDB automatically determines where its
7324 shared libraries (if any) have been loaded, and reads their symbols.
7325 The `share' command is no longer needed. This also works when
7326 examining core files.
7330 You can specify the number of lines that the `list' command shows.
7333 * New machines supported (host and target)
7335 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7336 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7337 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7339 * New hosts supported (not targets)
7341 IBM RT/PC: romp-ibm-aix or rtpc
7343 * New targets supported (not hosts)
7345 AMD 29000 embedded with COFF a29k-none-coff
7346 AMD 29000 embedded with a.out a29k-none-aout
7347 Ultracomputer remote kernel debug a29k-nyu-kern
7349 * New remote interfaces
7355 *** Changes in GDB-4.0:
7359 Wide output is wrapped at good places to make the output more readable.
7361 Gdb now supports cross-debugging from a host machine of one type to a
7362 target machine of another type. Communication with the target system
7363 is over serial lines. The ``target'' command handles connecting to the
7364 remote system; the ``load'' command will download a program into the
7365 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7366 also supports debugging of realtime processes running under VxWorks,
7367 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7368 stub on the target system.
7370 New CPUs supported include the AMD 29000 and Intel 960.
7372 GDB now reads object files and symbol tables via a ``binary file''
7373 library, which allows a single copy of GDB to debug programs of multiple
7374 object file types such as a.out and coff.
7376 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7377 refcard.dvi and refcard.ps are available to format it).
7380 * Control-Variable user interface simplified
7382 All variables that control the operation of the debugger can be set
7383 by the ``set'' command, and displayed by the ``show'' command.
7385 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7386 ``Show prompt'' produces the response:
7387 Gdb's prompt is new-gdb=>.
7389 What follows are the NEW set commands. The command ``help set'' will
7390 print a complete list of old and new set commands. ``help set FOO''
7391 will give a longer description of the variable FOO. ``show'' will show
7392 all of the variable descriptions and their current settings.
7394 confirm on/off: Enables warning questions for operations that are
7395 hard to recover from, e.g. rerunning the program while
7396 it is already running. Default is ON.
7398 editing on/off: Enables EMACS style command line editing
7399 of input. Previous lines can be recalled with
7400 control-P, the current line can be edited with control-B,
7401 you can search for commands with control-R, etc.
7404 history filename NAME: NAME is where the gdb command history
7405 will be stored. The default is .gdb_history,
7406 or the value of the environment variable
7409 history size N: The size, in commands, of the command history. The
7410 default is 256, or the value of the environment variable
7413 history save on/off: If this value is set to ON, the history file will
7414 be saved after exiting gdb. If set to OFF, the
7415 file will not be saved. The default is OFF.
7417 history expansion on/off: If this value is set to ON, then csh-like
7418 history expansion will be performed on
7419 command line input. The default is OFF.
7421 radix N: Sets the default radix for input and output. It can be set
7422 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7423 in the current radix, so "set radix 10" is always a no-op.
7425 height N: This integer value is the number of lines on a page. Default
7426 is 24, the current `stty rows'' setting, or the ``li#''
7427 setting from the termcap entry matching the environment
7430 width N: This integer value is the number of characters on a line.
7431 Default is 80, the current `stty cols'' setting, or the ``co#''
7432 setting from the termcap entry matching the environment
7435 Note: ``set screensize'' is obsolete. Use ``set height'' and
7436 ``set width'' instead.
7438 print address on/off: Print memory addresses in various command displays,
7439 such as stack traces and structure values. Gdb looks
7440 more ``symbolic'' if you turn this off; it looks more
7441 ``machine level'' with it on. Default is ON.
7443 print array on/off: Prettyprint arrays. New convenient format! Default
7446 print demangle on/off: Print C++ symbols in "source" form if on,
7449 print asm-demangle on/off: Same, for assembler level printouts
7452 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7455 * Support for Epoch Environment.
7457 The epoch environment is a version of Emacs v18 with windowing. One
7458 new command, ``inspect'', is identical to ``print'', except that if you
7459 are running in the epoch environment, the value is printed in its own
7463 * Support for Shared Libraries
7465 GDB can now debug programs and core files that use SunOS shared libraries.
7466 Symbols from a shared library cannot be referenced
7467 before the shared library has been linked with the program (this
7468 happens after you type ``run'' and before the function main() is entered).
7469 At any time after this linking (including when examining core files
7470 from dynamically linked programs), gdb reads the symbols from each
7471 shared library when you type the ``sharedlibrary'' command.
7472 It can be abbreviated ``share''.
7474 sharedlibrary REGEXP: Load shared object library symbols for files
7475 matching a unix regular expression. No argument
7476 indicates to load symbols for all shared libraries.
7478 info sharedlibrary: Status of loaded shared libraries.
7483 A watchpoint stops execution of a program whenever the value of an
7484 expression changes. Checking for this slows down execution
7485 tremendously whenever you are in the scope of the expression, but is
7486 quite useful for catching tough ``bit-spreader'' or pointer misuse
7487 problems. Some machines such as the 386 have hardware for doing this
7488 more quickly, and future versions of gdb will use this hardware.
7490 watch EXP: Set a watchpoint (breakpoint) for an expression.
7492 info watchpoints: Information about your watchpoints.
7494 delete N: Deletes watchpoint number N (same as breakpoints).
7495 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7496 enable N: Re-enables watchpoint number N (same as breakpoints).
7499 * C++ multiple inheritance
7501 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7504 * C++ exception handling
7506 Gdb now supports limited C++ exception handling. Besides the existing
7507 ability to breakpoint on an exception handler, gdb can breakpoint on
7508 the raising of an exception (before the stack is peeled back to the
7511 catch FOO: If there is a FOO exception handler in the dynamic scope,
7512 set a breakpoint to catch exceptions which may be raised there.
7513 Multiple exceptions (``catch foo bar baz'') may be caught.
7515 info catch: Lists all exceptions which may be caught in the
7516 current stack frame.
7519 * Minor command changes
7521 The command ``call func (arg, arg, ...)'' now acts like the print
7522 command, except it does not print or save a value if the function's result
7523 is void. This is similar to dbx usage.
7525 The ``up'' and ``down'' commands now always print the frame they end up
7526 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7527 frames without printing.
7529 * New directory command
7531 'dir' now adds directories to the FRONT of the source search path.
7532 The path starts off empty. Source files that contain debug information
7533 about the directory in which they were compiled can be found even
7534 with an empty path; Sun CC and GCC include this information. If GDB can't
7535 find your source file in the current directory, type "dir .".
7537 * Configuring GDB for compilation
7539 For normal use, type ``./configure host''. See README or gdb.texinfo
7542 GDB now handles cross debugging. If you are remotely debugging between
7543 two different machines, type ``./configure host -target=targ''.
7544 Host is the machine where GDB will run; targ is the machine
7545 where the program that you are debugging will run.