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.
123 The GDB printf and eval commands can now print C-style and Ada-style
124 string convenience variables without calling functions in the program.
125 This allows to do formatted printing of strings without having
126 a running inferior, or when debugging a core dump.
129 The "show style" and its subcommands are now styling
130 a style name in their output using its own style, to help
131 the user visualize the different styles.
133 set print raw-frame-arguments
134 show print raw-frame-arguments
136 These commands replace the similarly-named "set/show print raw
137 frame-arguments" commands (now with a dash instead of a space). The
138 old commands are now deprecated and may be removed in a future
141 maint test-options require-delimiter
142 maint test-options unknown-is-error
143 maint test-options unknown-is-operand
144 maint show test-options-completion-result
145 Commands used by the testsuite to validate the command options
148 * New command options, command completion
150 GDB now has a standard infrastructure to support dash-style command
151 options ('-OPT'). One benefit is that commands that use it can
152 easily support completion of command line arguments. Try "CMD
153 -[TAB]" or "help CMD" to find options supported by a command. Over
154 time, we intend to migrate most commands to this infrastructure. A
155 number of commands got support for new command options in this
158 ** The "print" and "compile print" commands now support a number of
159 options that allow overriding relevant global print settings as
160 set by "set print" subcommands:
164 -array-indexes [on|off]
165 -elements NUMBER|unlimited
169 -repeats NUMBER|unlimited
170 -static-members [on|off]
175 Note that because the "print"/"compile print" commands accept
176 arbitrary expressions which may look like options (including
177 abbreviations), if you specify any command option, then you must
178 use a double dash ("--") to mark the end of argument processing.
180 ** The "backtrace" command now supports a number of options that
181 allow overriding relevant global print settings as set by "set
182 backtrace" and "set print" subcommands:
184 -entry-values no|only|preferred|if-needed|both|compact|default
185 -frame-arguments all|scalars|none
186 -raw-frame-arguments [on|off]
190 In addition, the full/no-filters/hide qualifiers are now also
191 exposed as command options too:
197 ** The "frame apply", "tfaas" and "faas" commands similarly now
198 support the following options:
203 All options above can also be abbreviated. The argument of boolean
204 (on/off) options can be 0/1 too, and also the argument is assumed
205 "on" if omitted. This allows writing compact command invocations,
208 (gdb) p -r -p -o 0 -- *myptr
210 The above is equivalent to:
212 (gdb) print -raw -pretty -object off -- *myptr
214 ** The "info types" command now supports the '-q' flag to disable
215 printing of some header information in a similar fashion to "info
216 variables" and "info functions".
218 * Completion improvements
220 ** GDB can now complete the options of the "thread apply all" and
221 "taas" commands, and their "-ascending" option can now be
224 ** GDB can now complete the options of the "info threads", "info
225 functions", "info variables", "info locals", and "info args"
228 ** GDB can now complete the options of the "compile file" and
229 "compile code" commands. The "compile file" command now
230 completes on filenames.
232 ** GDB can now complete the backtrace command's
233 "full/no-filters/hide" qualifiers.
235 * In settings, you can now abbreviate "unlimited".
237 E.g., "set print elements u" is now equivalent to "set print
243 This lists all the possible completions for the rest of the line, if it
244 were to be given as a command itself. This is intended for use by MI
245 frontends in cases when separate CLI and MI channels cannot be used.
247 -catch-throw, -catch-rethrow, and -catch-catch
248 These can be used to catch C++ exceptions in a similar fashion to
249 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
253 The testsuite now creates the files gdb.cmd (containing the arguments
254 used to launch GDB) and gdb.in (containing all the commands sent to
255 GDB) in the output directory for each test script. Multiple invocations
256 are appended with .1, .2, .3 etc.
258 *** Changes in GDB 8.3
260 * GDB and GDBserver now support access to additional registers on
261 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
264 * GDB now has experimental support for the compilation and injection of
265 C++ source code into the inferior. This beta release does not include
266 support for several language features, such as templates, constructors,
269 This feature requires GCC 7.1 or higher built with libcp1.so
272 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
273 can be passed using the '[ADDRESS]:PORT' notation, or the regular
274 'ADDRESS:PORT' method.
276 * DWARF index cache: GDB can now automatically save indices of DWARF
277 symbols on disk to speed up further loading of the same binaries.
279 * Ada task switching is now supported on aarch64-elf targets when
280 debugging a program using the Ravenscar Profile. For more information,
281 see the "Tasking Support when using the Ravenscar Profile" section
282 in the GDB user manual.
284 * GDB in batch mode now exits with status 1 if the last command to be
287 * The RISC-V target now supports target descriptions.
289 * System call catchpoints now support system call aliases on FreeBSD.
290 When the ABI of a system call changes in FreeBSD, this is
291 implemented by leaving a compatibility system call using the old ABI
292 at the existing number and allocating a new system call number for
293 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
294 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
295 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
296 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
297 so that a system call catchpoint for the 'kevent' system call will
298 catch invocations of both the 'kevent' and 'freebsd11_kevent'
299 binaries. This ensures that 'kevent' system calls are caught for
300 binaries using either the old or new ABIs.
302 * Terminal styling is now available for the CLI and the TUI. GNU
303 Source Highlight can additionally be used to provide styling of
304 source code snippets. See the "set style" commands, below, for more
307 * Removed support for old demangling styles arm, edg, gnu, hp and
312 set debug compile-cplus-types
313 show debug compile-cplus-types
314 Control the display of debug output about type conversion in the
315 C++ compile feature. Commands have no effect while compiliong
320 Control whether debug output about files/functions skipping is
323 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
324 Apply a command to some frames.
325 FLAG arguments allow to control what output to produce and how to handle
326 errors raised when applying COMMAND to a frame.
329 Apply a command to all threads (ignoring errors and empty output).
330 Shortcut for 'thread apply all -s COMMAND'.
333 Apply a command to all frames (ignoring errors and empty output).
334 Shortcut for 'frame apply all -s COMMAND'.
337 Apply a command to all frames of all threads (ignoring errors and empty
339 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
341 maint set dwarf unwinders (on|off)
342 maint show dwarf unwinders
343 Control whether DWARF unwinders can be used.
346 Display a list of open files for a process.
350 Changes to the "frame", "select-frame", and "info frame" CLI commands.
351 These commands all now take a frame specification which
352 is either a frame level, or one of the keywords 'level', 'address',
353 'function', or 'view' followed by a parameter. Selecting a frame by
354 address, or viewing a frame outside the current backtrace now
355 requires the use of a keyword. Selecting a frame by level is
356 unchanged. The MI comment "-stack-select-frame" is unchanged.
358 target remote FILENAME
359 target extended-remote FILENAME
360 If FILENAME is a Unix domain socket, GDB will attempt to connect
361 to this socket instead of opening FILENAME as a character device.
363 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
364 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
365 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
366 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
367 These commands can now print only the searched entities
368 matching the provided regexp(s), giving a condition
369 on the entity names or entity types. The flag -q disables
370 printing headers or informations messages.
376 These commands now determine the syntax for the shown entities
377 according to the language chosen by `set language'. In particular,
378 `set language auto' means to automatically choose the language of
381 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
382 The 'thread apply' command accepts new FLAG arguments.
383 FLAG arguments allow to control what output to produce and how to handle
384 errors raised when applying COMMAND to a thread.
386 set tui tab-width NCHARS
387 show tui tab-width NCHARS
388 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
390 set style enabled [on|off]
392 Enable or disable terminal styling. Styling is enabled by default
393 on most hosts, but disabled by default when in batch mode.
395 set style sources [on|off]
397 Enable or disable source code styling. Source code styling is
398 enabled by default, but only takes effect if styling in general is
399 enabled, and if GDB was linked with GNU Source Highlight.
401 set style filename foreground COLOR
402 set style filename background COLOR
403 set style filename intensity VALUE
404 Control the styling of file names.
406 set style function foreground COLOR
407 set style function background COLOR
408 set style function intensity VALUE
409 Control the styling of function names.
411 set style variable foreground COLOR
412 set style variable background COLOR
413 set style variable intensity VALUE
414 Control the styling of variable names.
416 set style address foreground COLOR
417 set style address background COLOR
418 set style address intensity VALUE
419 Control the styling of addresses.
423 ** The default version of the MI interpreter is now 3 (-i=mi3).
425 ** The '-data-disassemble' MI command now accepts an '-a' option to
426 disassemble the whole function surrounding the given program
427 counter value or function name. Support for this feature can be
428 verified by using the "-list-features" command, which should
429 contain "data-disassemble-a-option".
431 ** Command responses and notifications that include a frame now include
432 the frame's architecture in a new "arch" attribute.
434 ** The output of information about multi-location breakpoints (which is
435 syntactically incorrect in MI 2) has changed in MI 3. This affects
436 the following commands and events:
440 - =breakpoint-created
441 - =breakpoint-modified
443 The -fix-multi-location-breakpoint-output command can be used to enable
444 this behavior with previous MI versions.
446 * New native configurations
448 GNU/Linux/RISC-V riscv*-*-linux*
449 FreeBSD/riscv riscv*-*-freebsd*
453 GNU/Linux/RISC-V riscv*-*-linux*
455 CSKY GNU/LINUX csky*-*-linux
456 FreeBSD/riscv riscv*-*-freebsd*
458 GNU/Linux/OpenRISC or1k*-*-linux*
462 GDB no longer supports native debugging on versions of MS-Windows
467 ** GDB no longer supports Python versions less than 2.6.
469 ** The gdb.Inferior type has a new 'progspace' property, which is the program
470 space associated to that inferior.
472 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
473 of objfiles associated to that program space.
475 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
476 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
479 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
480 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
481 correct and did not work properly.
483 ** The gdb.Value type has a new constructor, which is used to construct a
484 gdb.Value from a Python buffer object and a gdb.Type.
490 Enable or disable the undefined behavior sanitizer. This is
491 disabled by default, but passing --enable-ubsan=yes or
492 --enable-ubsan=auto to configure will enable it. Enabling this can
493 cause a performance penalty. The undefined behavior sanitizer was
494 first introduced in GCC 4.9.
496 *** Changes in GDB 8.2
498 * The 'set disassembler-options' command now supports specifying options
501 * The 'symbol-file' command now accepts an '-o' option to add a relative
502 offset to all sections.
504 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
505 a relative offset to all sections, but it allows to override the load
506 address of individual sections using '-s'.
508 * The 'add-symbol-file' command no longer requires the second argument
509 (address of the text section).
511 * The endianness used with the 'set endian auto' mode in the absence of
512 an executable selected for debugging is now the last endianness chosen
513 either by one of the 'set endian big' and 'set endian little' commands
514 or by inferring from the last executable used, rather than the startup
517 * The pager now allows a "c" response, meaning to disable the pager
518 for the rest of the current command.
520 * The commands 'info variables/functions/types' now show the source line
521 numbers of symbol definitions when available.
523 * 'info proc' now works on running processes on FreeBSD systems and core
524 files created on FreeBSD systems.
526 * C expressions can now use _Alignof, and C++ expressions can now use
529 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
530 the vector length while the process is running.
536 Control display of debugging info regarding the FreeBSD native target.
538 set|show varsize-limit
539 This new setting allows the user to control the maximum size of Ada
540 objects being printed when those objects have a variable type,
541 instead of that maximum size being hardcoded to 65536 bytes.
543 set|show record btrace cpu
544 Controls the processor to be used for enabling errata workarounds for
547 maint check libthread-db
548 Run integrity checks on the current inferior's thread debugging
551 maint set check-libthread-db (on|off)
552 maint show check-libthread-db
553 Control whether to run integrity checks on inferior specific thread
554 debugging libraries as they are loaded. The default is not to
559 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
561 ** The commands attached to a breakpoint can be set by assigning to
562 the breakpoint's "commands" field.
564 ** gdb.execute can now execute multi-line gdb commands.
566 ** The new functions gdb.convenience_variable and
567 gdb.set_convenience_variable can be used to get and set the value
568 of convenience variables.
570 ** A gdb.Parameter will no longer print the "set" help text on an
571 ordinary "set"; instead by default a "set" will be silent unless
572 the get_set_string method returns a non-empty string.
576 RiscV ELF riscv*-*-elf
578 * Removed targets and native configurations
580 m88k running OpenBSD m88*-*-openbsd*
581 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
582 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
583 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
585 * Aarch64/Linux hardware watchpoints improvements
587 Hardware watchpoints on unaligned addresses are now properly
588 supported when running Linux kernel 4.10 or higher: read and access
589 watchpoints are no longer spuriously missed, and all watchpoints
590 lengths between 1 and 8 bytes are supported. On older kernels,
591 watchpoints set on unaligned addresses are no longer missed, with
592 the tradeoff that there is a possibility of false hits being
597 --enable-codesign=CERT
598 This can be used to invoke "codesign -s CERT" after building gdb.
599 This option is useful on macOS, where code signing is required for
600 gdb to work properly.
602 --disable-gdbcli has been removed
603 This is now silently accepted, but does nothing.
605 *** Changes in GDB 8.1
607 * GDB now supports dynamically creating arbitrary register groups specified
608 in XML target descriptions. This allows for finer grain grouping of
609 registers on systems with a large amount of registers.
611 * The 'ptype' command now accepts a '/o' flag, which prints the
612 offsets and sizes of fields in a struct, like the pahole(1) tool.
614 * New "--readnever" command line option instructs GDB to not read each
615 symbol file's symbolic debug information. This makes startup faster
616 but at the expense of not being able to perform symbolic debugging.
617 This option is intended for use cases where symbolic debugging will
618 not be used, e.g., when you only need to dump the debuggee's core.
620 * GDB now uses the GNU MPFR library, if available, to emulate target
621 floating-point arithmetic during expression evaluation when the target
622 uses different floating-point formats than the host. At least version
623 3.1 of GNU MPFR is required.
625 * GDB now supports access to the guarded-storage-control registers and the
626 software-based guarded-storage broadcast control registers on IBM z14.
628 * On Unix systems, GDB now supports transmitting environment variables
629 that are to be set or unset to GDBserver. These variables will
630 affect the environment to be passed to the remote inferior.
632 To inform GDB of environment variables that are to be transmitted to
633 GDBserver, use the "set environment" command. Only user set
634 environment variables are sent to GDBserver.
636 To inform GDB of environment variables that are to be unset before
637 the remote inferior is started by the GDBserver, use the "unset
638 environment" command.
640 * Completion improvements
642 ** GDB can now complete function parameters in linespecs and
643 explicit locations without quoting. When setting breakpoints,
644 quoting around functions names to help with TAB-completion is
645 generally no longer necessary. For example, this now completes
648 (gdb) b function(in[TAB]
649 (gdb) b function(int)
651 Related, GDB is no longer confused with completing functions in
652 C++ anonymous namespaces:
655 (gdb) b (anonymous namespace)::[TAB][TAB]
656 (anonymous namespace)::a_function()
657 (anonymous namespace)::b_function()
659 ** GDB now has much improved linespec and explicit locations TAB
660 completion support, that better understands what you're
661 completing and offers better suggestions. For example, GDB no
662 longer offers data symbols as possible completions when you're
663 setting a breakpoint.
665 ** GDB now TAB-completes label symbol names.
667 ** The "complete" command now mimics TAB completion accurately.
669 * New command line options (gcore)
672 Dump all memory mappings.
674 * Breakpoints on C++ functions are now set on all scopes by default
676 By default, breakpoints on functions/methods are now interpreted as
677 specifying all functions with the given name ignoring missing
678 leading scopes (namespaces and classes).
680 For example, assuming a C++ program with symbols named:
685 both commands "break func()" and "break B::func()" set a breakpoint
688 You can use the new flag "-qualified" to override this. This makes
689 GDB interpret the specified function name as a complete
690 fully-qualified name instead. For example, using the same C++
691 program, the "break -q B::func" command sets a breakpoint on
692 "B::func", only. A parameter has been added to the Python
693 gdb.Breakpoint constructor to achieve the same result when creating
694 a breakpoint from Python.
696 * Breakpoints on functions marked with C++ ABI tags
698 GDB can now set breakpoints on functions marked with C++ ABI tags
699 (e.g., [abi:cxx11]). See here for a description of ABI tags:
700 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
702 Functions with a C++11 abi tag are demangled/displayed like this:
704 function[abi:cxx11](int)
707 You can now set a breakpoint on such functions simply as if they had
710 (gdb) b function(int)
712 Or if you need to disambiguate between tags, like:
714 (gdb) b function[abi:other_tag](int)
716 Tab completion was adjusted accordingly as well.
720 ** New events gdb.new_inferior, gdb.inferior_deleted, and
721 gdb.new_thread are emitted. See the manual for further
722 description of these.
724 ** A new function, "gdb.rbreak" has been added to the Python API.
725 This function allows the setting of a large number of breakpoints
726 via a regex pattern in Python. See the manual for further details.
728 ** Python breakpoints can now accept explicit locations. See the
729 manual for a further description of this feature.
732 * New features in the GDB remote stub, GDBserver
734 ** GDBserver is now able to start inferior processes with a
735 specified initial working directory.
737 The user can set the desired working directory to be used from
738 GDB using the new "set cwd" command.
740 ** New "--selftest" command line option runs some GDBserver self
741 tests. These self tests are disabled in releases.
743 ** On Unix systems, GDBserver now does globbing expansion and variable
744 substitution in inferior command line arguments.
746 This is done by starting inferiors using a shell, like GDB does.
747 See "set startup-with-shell" in the user manual for how to disable
748 this from GDB when using "target extended-remote". When using
749 "target remote", you can disable the startup with shell by using the
750 new "--no-startup-with-shell" GDBserver command line option.
752 ** On Unix systems, GDBserver now supports receiving environment
753 variables that are to be set or unset from GDB. These variables
754 will affect the environment to be passed to the inferior.
756 * When catching an Ada exception raised with a message, GDB now prints
757 the message in the catchpoint hit notification. In GDB/MI mode, that
758 information is provided as an extra field named "exception-message"
759 in the *stopped notification.
761 * Trait objects can now be inspected When debugging Rust code. This
762 requires compiler support which will appear in Rust 1.24.
766 QEnvironmentHexEncoded
767 Inform GDBserver of an environment variable that is to be passed to
768 the inferior when starting it.
771 Inform GDBserver of an environment variable that is to be unset
772 before starting the remote inferior.
775 Inform GDBserver that the environment should be reset (i.e.,
776 user-set environment variables should be unset).
779 Indicates whether the inferior must be started with a shell or not.
782 Tell GDBserver that the inferior to be started should use a specific
785 * The "maintenance print c-tdesc" command now takes an optional
786 argument which is the file name of XML target description.
788 * The "maintenance selftest" command now takes an optional argument to
789 filter the tests to be run.
791 * The "enable", and "disable" commands now accept a range of
792 breakpoint locations, e.g. "enable 1.3-5".
797 Set and show the current working directory for the inferior.
800 Set and show compilation command used for compiling and injecting code
801 with the 'compile' commands.
803 set debug separate-debug-file
804 show debug separate-debug-file
805 Control the display of debug output about separate debug file search.
807 set dump-excluded-mappings
808 show dump-excluded-mappings
809 Control whether mappings marked with the VM_DONTDUMP flag should be
810 dumped when generating a core file.
813 List the registered selftests.
816 Start the debugged program stopping at the first instruction.
819 Control display of debugging messages related to OpenRISC targets.
821 set|show print type nested-type-limit
822 Set and show the limit of nesting level for nested types that the
823 type printer will show.
825 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
828 * Safer/improved support for debugging with no debug info
830 GDB no longer assumes functions with no debug information return
833 This means that GDB now refuses to call such functions unless you
834 tell it the function's type, by either casting the call to the
835 declared return type, or by casting the function to a function
836 pointer of the right type, and calling that:
838 (gdb) p getenv ("PATH")
839 'getenv' has unknown return type; cast the call to its declared return type
840 (gdb) p (char *) getenv ("PATH")
841 $1 = 0x7fffffffe "/usr/local/bin:/"...
842 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
843 $2 = 0x7fffffffe "/usr/local/bin:/"...
845 Similarly, GDB no longer assumes that global variables with no debug
846 info have type 'int', and refuses to print the variable's value
847 unless you tell it the variable's type:
850 'var' has unknown type; cast it to its declared type
854 * New native configurations
856 FreeBSD/aarch64 aarch64*-*-freebsd*
857 FreeBSD/arm arm*-*-freebsd*
861 FreeBSD/aarch64 aarch64*-*-freebsd*
862 FreeBSD/arm arm*-*-freebsd*
863 OpenRISC ELF or1k*-*-elf
865 * Removed targets and native configurations
867 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
869 *** Changes in GDB 8.0
871 * GDB now supports access to the PKU register on GNU/Linux. The register is
872 added by the Memory Protection Keys for Userspace feature which will be
873 available in future Intel CPUs.
875 * GDB now supports C++11 rvalue references.
879 ** New functions to start, stop and access a running btrace recording.
880 ** Rvalue references are now supported in gdb.Type.
882 * GDB now supports recording and replaying rdrand and rdseed Intel 64
885 * Building GDB and GDBserver now requires a C++11 compiler.
887 For example, GCC 4.8 or later.
889 It is no longer possible to build GDB or GDBserver with a C
890 compiler. The --disable-build-with-cxx configure option has been
893 * Building GDB and GDBserver now requires GNU make >= 3.81.
895 It is no longer supported to build GDB or GDBserver with another
896 implementation of the make program or an earlier version of GNU make.
898 * Native debugging on MS-Windows supports command-line redirection
900 Command-line arguments used for starting programs on MS-Windows can
901 now include redirection symbols supported by native Windows shells,
902 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
903 as "run", "start", and "set args", as well as the corresponding MI
906 * Support for thread names on MS-Windows.
908 GDB now catches and handles the special exception that programs
909 running on MS-Windows use to assign names to threads in the
912 * Support for Java programs compiled with gcj has been removed.
914 * User commands now accept an unlimited number of arguments.
915 Previously, only up to 10 was accepted.
917 * The "eval" command now expands user-defined command arguments.
919 This makes it easier to process a variable number of arguments:
924 eval "print $arg%d", $i
929 * Target descriptions can now describe registers for sparc32 and sparc64.
931 * GDB now supports DWARF version 5 (debug information format).
932 Its .debug_names index is not yet supported.
934 * New native configurations
936 FreeBSD/mips mips*-*-freebsd
940 Synopsys ARC arc*-*-elf32
941 FreeBSD/mips mips*-*-freebsd
943 * Removed targets and native configurations
945 Alpha running FreeBSD alpha*-*-freebsd*
946 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
951 Erases all the flash memory regions reported by the target.
953 maint print arc arc-instruction address
954 Print internal disassembler information about instruction at a given address.
958 set disassembler-options
959 show disassembler-options
960 Controls the passing of target specific information to the disassembler.
961 If it is necessary to specify more than one disassembler option then
962 multiple options can be placed together into a comma separated list.
963 The default value is the empty string. Currently, the only supported
964 targets are ARM, PowerPC and S/390.
969 Erases all the flash memory regions reported by the target. This is
970 equivalent to the CLI command flash-erase.
972 -file-list-shared-libraries
973 List the shared libraries in the program. This is
974 equivalent to the CLI command "info shared".
977 Catchpoints stopping the program when Ada exceptions are
978 handled. This is equivalent to the CLI command "catch handlers".
980 *** Changes in GDB 7.12
982 * GDB and GDBserver now build with a C++ compiler by default.
984 The --enable-build-with-cxx configure option is now enabled by
985 default. One must now explicitly configure with
986 --disable-build-with-cxx in order to build with a C compiler. This
987 option will be removed in a future release.
989 * GDBserver now supports recording btrace without maintaining an active
992 * GDB now supports a negative repeat count in the 'x' command to examine
993 memory backward from the given address. For example:
996 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
997 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
998 (gdb) x/-5i 0x0000000000400580
999 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1000 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1001 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1002 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1003 0x40057b <main(int, char**)+25>:
1004 callq 0x400536 <Func1(int, char const*)>
1006 * Fortran: Support structures with fields of dynamic types and
1007 arrays of dynamic types.
1009 * The symbol dumping maintenance commands have new syntax.
1010 maint print symbols [-pc address] [--] [filename]
1011 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1012 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1013 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1014 maint print msymbols [-objfile objfile] [--] [filename]
1016 * GDB now supports multibit bitfields and enums in target register
1019 * New Python-based convenience function $_as_string(val), which returns
1020 the textual representation of a value. This function is especially
1021 useful to obtain the text label of an enum value.
1023 * Intel MPX bound violation handling.
1025 Segmentation faults caused by a Intel MPX boundary violation
1026 now display the kind of violation (upper or lower), the memory
1027 address accessed and the memory bounds, along with the usual
1028 signal received and code location.
1032 Program received signal SIGSEGV, Segmentation fault
1033 Upper bound violation while accessing address 0x7fffffffc3b3
1034 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1035 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1037 * Rust language support.
1038 GDB now supports debugging programs written in the Rust programming
1039 language. See https://www.rust-lang.org/ for more information about
1042 * Support for running interpreters on specified input/output devices
1044 GDB now supports a new mechanism that allows frontends to provide
1045 fully featured GDB console views, as a better alternative to
1046 building such views on top of the "-interpreter-exec console"
1047 command. See the new "new-ui" command below. With that command,
1048 frontends can now start GDB in the traditional command-line mode
1049 running in an embedded terminal emulator widget, and create a
1050 separate MI interpreter running on a specified i/o device. In this
1051 way, GDB handles line editing, history, tab completion, etc. in the
1052 console all by itself, and the GUI uses the separate MI interpreter
1053 for its own control and synchronization, invisible to the command
1056 * The "catch syscall" command catches groups of related syscalls.
1058 The "catch syscall" command now supports catching a group of related
1059 syscalls using the 'group:' or 'g:' prefix.
1064 skip -gfile file-glob-pattern
1065 skip -function function
1066 skip -rfunction regular-expression
1067 A generalized form of the skip command, with new support for
1068 glob-style file names and regular expressions for function names.
1069 Additionally, a file spec and a function spec may now be combined.
1071 maint info line-table REGEXP
1072 Display the contents of GDB's internal line table data struture.
1075 Run any GDB unit tests that were compiled in.
1078 Start a new user interface instance running INTERP as interpreter,
1079 using the TTY file for input/output.
1083 ** gdb.Breakpoint objects have a new attribute "pending", which
1084 indicates whether the breakpoint is pending.
1085 ** Three new breakpoint-related events have been added:
1086 gdb.breakpoint_created, gdb.breakpoint_modified, and
1087 gdb.breakpoint_deleted.
1089 signal-event EVENTID
1090 Signal ("set") the given MS-Windows event object. This is used in
1091 conjunction with the Windows JIT debugging (AeDebug) support, where
1092 the OS suspends a crashing process until a debugger can attach to
1093 it. Resuming the crashing process, in order to debug it, is done by
1094 signalling an event.
1096 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1097 was added in GDBserver, including JIT compiling fast tracepoint's
1098 conditional expression bytecode into native code.
1100 * Support for various remote target protocols and ROM monitors has
1103 target m32rsdi Remote M32R debugging over SDI
1104 target mips MIPS remote debugging protocol
1105 target pmon PMON ROM monitor
1106 target ddb NEC's DDB variant of PMON for Vr4300
1107 target rockhopper NEC RockHopper variant of PMON
1108 target lsi LSI variant of PMO
1110 * Support for tracepoints and fast tracepoints on powerpc-linux,
1111 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1112 including JIT compiling fast tracepoint's conditional expression
1113 bytecode into native code.
1115 * MI async record =record-started now includes the method and format used for
1116 recording. For example:
1118 =record-started,thread-group="i1",method="btrace",format="bts"
1120 * MI async record =thread-selected now includes the frame field. For example:
1122 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1126 Andes NDS32 nds32*-*-elf
1128 *** Changes in GDB 7.11
1130 * GDB now supports debugging kernel-based threads on FreeBSD.
1132 * Per-inferior thread numbers
1134 Thread numbers are now per inferior instead of global. If you're
1135 debugging multiple inferiors, GDB displays thread IDs using a
1136 qualified INF_NUM.THR_NUM form. For example:
1140 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1141 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1142 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1143 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1145 As consequence, thread numbers as visible in the $_thread
1146 convenience variable and in Python's InferiorThread.num attribute
1147 are no longer unique between inferiors.
1149 GDB now maintains a second thread ID per thread, referred to as the
1150 global thread ID, which is the new equivalent of thread numbers in
1151 previous releases. See also $_gthread below.
1153 For backwards compatibility, MI's thread IDs always refer to global
1156 * Commands that accept thread IDs now accept the qualified
1157 INF_NUM.THR_NUM form as well. For example:
1160 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1163 * In commands that accept a list of thread IDs, you can now refer to
1164 all threads of an inferior using a star wildcard. GDB accepts
1165 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1166 refer to all threads of the current inferior. For example, "info
1169 * You can use "info threads -gid" to display the global thread ID of
1172 * The new convenience variable $_gthread holds the global number of
1175 * The new convenience variable $_inferior holds the number of the
1178 * GDB now displays the ID and name of the thread that hit a breakpoint
1179 or received a signal, if your program is multi-threaded. For
1182 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1183 Thread 1 "main" received signal SIGINT, Interrupt.
1185 * Record btrace now supports non-stop mode.
1187 * Support for tracepoints on aarch64-linux was added in GDBserver.
1189 * The 'record instruction-history' command now indicates speculative execution
1190 when using the Intel Processor Trace recording format.
1192 * GDB now allows users to specify explicit locations, bypassing
1193 the linespec parser. This feature is also available to GDB/MI
1196 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1197 GDB now is able to debug both AArch64 applications and ARM applications
1200 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1201 including JIT compiling fast tracepoint's conditional expression bytecode
1204 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1206 * "info threads", "info inferiors", "info display", "info checkpoints"
1207 and "maint info program-spaces" now list the corresponding items in
1208 ascending ID order, for consistency with all other "info" commands.
1210 * In Ada, the overloads selection menu has been enhanced to display the
1211 parameter types and the return types for the matching overloaded subprograms.
1215 maint set target-non-stop (on|off|auto)
1216 maint show target-non-stop
1217 Control whether GDB targets always operate in non-stop mode even if
1218 "set non-stop" is "off". The default is "auto", meaning non-stop
1219 mode is enabled if supported by the target.
1221 maint set bfd-sharing
1222 maint show bfd-sharing
1223 Control the reuse of bfd objects.
1226 show debug bfd-cache
1227 Control display of debugging info regarding bfd caching.
1231 Control display of debugging info regarding FreeBSD threads.
1233 set remote multiprocess-extensions-packet
1234 show remote multiprocess-extensions-packet
1235 Set/show the use of the remote protocol multiprocess extensions.
1237 set remote thread-events
1238 show remote thread-events
1239 Set/show the use of thread create/exit events.
1241 set ada print-signatures on|off
1242 show ada print-signatures"
1243 Control whether parameter types and return types are displayed in overloads
1244 selection menus. It is activaled (@code{on}) by default.
1248 Controls the maximum size of memory, in bytes, that GDB will
1249 allocate for value contents. Prevents incorrect programs from
1250 causing GDB to allocate overly large buffers. Default is 64k.
1252 * The "disassemble" command accepts a new modifier: /s.
1253 It prints mixed source+disassembly like /m with two differences:
1254 - disassembled instructions are now printed in program order, and
1255 - and source for all relevant files is now printed.
1256 The "/m" option is now considered deprecated: its "source-centric"
1257 output hasn't proved useful in practice.
1259 * The "record instruction-history" command accepts a new modifier: /s.
1260 It behaves exactly like /m and prints mixed source+disassembly.
1262 * The "set scheduler-locking" command supports a new mode "replay".
1263 It behaves like "off" in record mode and like "on" in replay mode.
1265 * Support for various ROM monitors has been removed:
1267 target dbug dBUG ROM monitor for Motorola ColdFire
1268 target picobug Motorola picobug monitor
1269 target dink32 DINK32 ROM monitor for PowerPC
1270 target m32r Renesas M32R/D ROM monitor
1271 target mon2000 mon2000 ROM monitor
1272 target ppcbug PPCBUG ROM monitor for PowerPC
1274 * Support for reading/writing memory and extracting values on architectures
1275 whose memory is addressable in units of any integral multiple of 8 bits.
1278 Allows to break when an Ada exception is handled.
1280 * New remote packets
1283 Indicates that an exec system call was executed.
1285 exec-events feature in qSupported
1286 The qSupported packet allows GDB to request support for exec
1287 events using the new 'gdbfeature' exec-event, and the qSupported
1288 response can contain the corresponding 'stubfeature'. Set and
1289 show commands can be used to display whether these features are enabled.
1292 Equivalent to interrupting with the ^C character, but works in
1295 thread created stop reason (T05 create:...)
1296 Indicates that the thread was just created and is stopped at entry.
1298 thread exit stop reply (w exitcode;tid)
1299 Indicates that the thread has terminated.
1302 Enables/disables thread create and exit event reporting. For
1303 example, this is used in non-stop mode when GDB stops a set of
1304 threads and synchronously waits for the their corresponding stop
1305 replies. Without exit events, if one of the threads exits, GDB
1306 would hang forever not knowing that it should no longer expect a
1307 stop for that same thread.
1310 Indicates that there are no resumed threads left in the target (all
1311 threads are stopped). The remote stub reports support for this stop
1312 reply to GDB's qSupported query.
1315 Enables/disables catching syscalls from the inferior process.
1316 The remote stub reports support for this packet to GDB's qSupported query.
1318 syscall_entry stop reason
1319 Indicates that a syscall was just called.
1321 syscall_return stop reason
1322 Indicates that a syscall just returned.
1324 * Extended-remote exec events
1326 ** GDB now has support for exec events on extended-remote Linux targets.
1327 For such targets with Linux kernels 2.5.46 and later, this enables
1328 follow-exec-mode and exec catchpoints.
1330 set remote exec-event-feature-packet
1331 show remote exec-event-feature-packet
1332 Set/show the use of the remote exec event feature.
1334 * Thread names in remote protocol
1336 The reply to qXfer:threads:read may now include a name attribute for each
1339 * Target remote mode fork and exec events
1341 ** GDB now has support for fork and exec events on target remote mode
1342 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1343 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1344 fork and exec catchpoints.
1346 * Remote syscall events
1348 ** GDB now has support for catch syscall on remote Linux targets,
1349 currently enabled on x86/x86_64 architectures.
1351 set remote catch-syscall-packet
1352 show remote catch-syscall-packet
1353 Set/show the use of the remote catch syscall feature.
1357 ** The -var-set-format command now accepts the zero-hexadecimal
1358 format. It outputs data in hexadecimal format with zero-padding on the
1363 ** gdb.InferiorThread objects have a new attribute "global_num",
1364 which refers to the thread's global thread ID. The existing
1365 "num" attribute now refers to the thread's per-inferior number.
1366 See "Per-inferior thread numbers" above.
1367 ** gdb.InferiorThread objects have a new attribute "inferior", which
1368 is the Inferior object the thread belongs to.
1370 *** Changes in GDB 7.10
1372 * Support for process record-replay and reverse debugging on aarch64*-linux*
1373 targets has been added. GDB now supports recording of A64 instruction set
1374 including advance SIMD instructions.
1376 * Support for Sun's version of the "stabs" debug file format has been removed.
1378 * GDB now honors the content of the file /proc/PID/coredump_filter
1379 (PID is the process ID) on GNU/Linux systems. This file can be used
1380 to specify the types of memory mappings that will be included in a
1381 corefile. For more information, please refer to the manual page of
1382 "core(5)". GDB also has a new command: "set use-coredump-filter
1383 on|off". It allows to set whether GDB will read the content of the
1384 /proc/PID/coredump_filter file when generating a corefile.
1386 * The "info os" command on GNU/Linux can now display information on
1388 "info os cpus" Listing of all cpus/cores on the system
1390 * GDB has two new commands: "set serial parity odd|even|none" and
1391 "show serial parity". These allows to set or show parity for the
1394 * The "info source" command now displays the producer string if it was
1395 present in the debug info. This typically includes the compiler version
1396 and may include things like its command line arguments.
1398 * The "info dll", an alias of the "info sharedlibrary" command,
1399 is now available on all platforms.
1401 * Directory names supplied to the "set sysroot" commands may be
1402 prefixed with "target:" to tell GDB to access shared libraries from
1403 the target system, be it local or remote. This replaces the prefix
1404 "remote:". The default sysroot has been changed from "" to
1405 "target:". "remote:" is automatically converted to "target:" for
1406 backward compatibility.
1408 * The system root specified by "set sysroot" will be prepended to the
1409 filename of the main executable (if reported to GDB as absolute by
1410 the operating system) when starting processes remotely, and when
1411 attaching to already-running local or remote processes.
1413 * GDB now supports automatic location and retrieval of executable
1414 files from remote targets. Remote debugging can now be initiated
1415 using only a "target remote" or "target extended-remote" command
1416 (no "set sysroot" or "file" commands are required). See "New remote
1419 * The "dump" command now supports verilog hex format.
1421 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1423 * On GNU/Linux, GDB and gdbserver are now able to access executable
1424 and shared library files without a "set sysroot" command when
1425 attaching to processes running in different mount namespaces from
1426 the debugger. This makes it possible to attach to processes in
1427 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1428 See "New remote packets" below.
1430 * The "tui reg" command now provides completion for all of the
1431 available register groups, including target specific groups.
1433 * The HISTSIZE environment variable is no longer read when determining
1434 the size of GDB's command history. GDB now instead reads the dedicated
1435 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1436 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1441 ** Memory ports can now be unbuffered.
1445 ** gdb.Objfile objects have a new attribute "username",
1446 which is the name of the objfile as specified by the user,
1447 without, for example, resolving symlinks.
1448 ** You can now write frame unwinders in Python.
1449 ** gdb.Type objects have a new method "optimized_out",
1450 returning optimized out gdb.Value instance of this type.
1451 ** gdb.Value objects have new methods "reference_value" and
1452 "const_value" which return a reference to the value and a
1453 "const" version of the value respectively.
1457 maint print symbol-cache
1458 Print the contents of the symbol cache.
1460 maint print symbol-cache-statistics
1461 Print statistics of symbol cache usage.
1463 maint flush-symbol-cache
1464 Flush the contents of the symbol cache.
1468 Start branch trace recording using Branch Trace Store (BTS) format.
1471 Evaluate expression by using the compiler and print result.
1475 Explicit commands for enabling and disabling tui mode.
1478 set mpx bound on i386 and amd64
1479 Support for bound table investigation on Intel MPX enabled applications.
1483 Start branch trace recording using Intel Processor Trace format.
1486 Print information about branch tracing internals.
1488 maint btrace packet-history
1489 Print the raw branch tracing data.
1491 maint btrace clear-packet-history
1492 Discard the stored raw branch tracing data.
1495 Discard all branch tracing data. It will be fetched and processed
1496 anew by the next "record" command.
1501 Renamed from "set debug dwarf2-die".
1502 show debug dwarf-die
1503 Renamed from "show debug dwarf2-die".
1505 set debug dwarf-read
1506 Renamed from "set debug dwarf2-read".
1507 show debug dwarf-read
1508 Renamed from "show debug dwarf2-read".
1510 maint set dwarf always-disassemble
1511 Renamed from "maint set dwarf2 always-disassemble".
1512 maint show dwarf always-disassemble
1513 Renamed from "maint show dwarf2 always-disassemble".
1515 maint set dwarf max-cache-age
1516 Renamed from "maint set dwarf2 max-cache-age".
1517 maint show dwarf max-cache-age
1518 Renamed from "maint show dwarf2 max-cache-age".
1520 set debug dwarf-line
1521 show debug dwarf-line
1522 Control display of debugging info regarding DWARF line processing.
1525 show max-completions
1526 Set the maximum number of candidates to be considered during
1527 completion. The default value is 200. This limit allows GDB
1528 to avoid generating large completion lists, the computation of
1529 which can cause the debugger to become temporarily unresponsive.
1531 set history remove-duplicates
1532 show history remove-duplicates
1533 Control the removal of duplicate history entries.
1535 maint set symbol-cache-size
1536 maint show symbol-cache-size
1537 Control the size of the symbol cache.
1539 set|show record btrace bts buffer-size
1540 Set and show the size of the ring buffer used for branch tracing in
1542 The obtained size may differ from the requested size. Use "info
1543 record" to see the obtained buffer size.
1545 set debug linux-namespaces
1546 show debug linux-namespaces
1547 Control display of debugging info regarding Linux namespaces.
1549 set|show record btrace pt buffer-size
1550 Set and show the size of the ring buffer used for branch tracing in
1551 Intel Processor Trace format.
1552 The obtained size may differ from the requested size. Use "info
1553 record" to see the obtained buffer size.
1555 maint set|show btrace pt skip-pad
1556 Set and show whether PAD packets are skipped when computing the
1559 * The command 'thread apply all' can now support new option '-ascending'
1560 to call its specified command for all threads in ascending order.
1562 * Python/Guile scripting
1564 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1565 special section named `.debug_gdb_scripts'.
1567 * New remote packets
1569 qXfer:btrace-conf:read
1570 Return the branch trace configuration for the current thread.
1572 Qbtrace-conf:bts:size
1573 Set the requested ring buffer size for branch tracing in BTS format.
1576 Enable Intel Procesor Trace-based branch tracing for the current
1577 process. The remote stub reports support for this packet to GDB's
1580 Qbtrace-conf:pt:size
1581 Set the requested ring buffer size for branch tracing in Intel Processor
1585 Indicates a memory breakpoint instruction was executed, irrespective
1586 of whether it was GDB that planted the breakpoint or the breakpoint
1587 is hardcoded in the program. This is required for correct non-stop
1591 Indicates the target stopped for a hardware breakpoint. This is
1592 required for correct non-stop mode operation.
1595 Return information about files on the remote system.
1597 qXfer:exec-file:read
1598 Return the full absolute name of the file that was executed to
1599 create a process running on the remote system.
1602 Select the filesystem on which vFile: operations with filename
1603 arguments will operate. This is required for GDB to be able to
1604 access files on remote targets where the remote stub does not
1605 share a common filesystem with the inferior(s).
1608 Indicates that a fork system call was executed.
1611 Indicates that a vfork system call was executed.
1613 vforkdone stop reason
1614 Indicates that a vfork child of the specified process has executed
1615 an exec or exit, allowing the vfork parent to resume execution.
1617 fork-events and vfork-events features in qSupported
1618 The qSupported packet allows GDB to request support for fork and
1619 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1620 and the qSupported response can contain the corresponding
1621 'stubfeatures'. Set and show commands can be used to display
1622 whether these features are enabled.
1624 * Extended-remote fork events
1626 ** GDB now has support for fork events on extended-remote Linux
1627 targets. For targets with Linux kernels 2.5.60 and later, this
1628 enables follow-fork-mode and detach-on-fork for both fork and
1629 vfork, as well as fork and vfork catchpoints.
1631 * The info record command now shows the recording format and the
1632 branch tracing configuration for the current thread when using
1633 the btrace record target.
1634 For the BTS format, it shows the ring buffer size.
1636 * GDB now has support for DTrace USDT (Userland Static Defined
1637 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1639 * GDB now supports access to vector registers on S/390 GNU/Linux
1642 * Removed command line options
1644 -xdb HP-UX XDB compatibility mode.
1646 * Removed targets and native configurations
1648 HP/PA running HP-UX hppa*-*-hpux*
1649 Itanium running HP-UX ia64-*-hpux*
1651 * New configure options
1654 This configure option allows the user to build GDB with support for
1655 Intel Processor Trace (default: auto). This requires libipt.
1657 --with-libipt-prefix=PATH
1658 Specify the path to the version of libipt that GDB should use.
1659 $PATH/include should contain the intel-pt.h header and
1660 $PATH/lib should contain the libipt.so library.
1662 *** Changes in GDB 7.9.1
1666 ** Xmethods can now specify a result type.
1668 *** Changes in GDB 7.9
1670 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1674 ** You can now access frame registers from Python scripts.
1675 ** New attribute 'producer' for gdb.Symtab objects.
1676 ** gdb.Objfile objects have a new attribute "progspace",
1677 which is the gdb.Progspace object of the containing program space.
1678 ** gdb.Objfile objects have a new attribute "owner".
1679 ** gdb.Objfile objects have a new attribute "build_id",
1680 which is the build ID generated when the file was built.
1681 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1682 ** A new event "gdb.clear_objfiles" has been added, triggered when
1683 selecting a new file to debug.
1684 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1685 ** New function gdb.lookup_objfile.
1687 New events which are triggered when GDB modifies the state of the
1690 ** gdb.events.inferior_call_pre: Function call is about to be made.
1691 ** gdb.events.inferior_call_post: Function call has just been made.
1692 ** gdb.events.memory_changed: A memory location has been altered.
1693 ** gdb.events.register_changed: A register has been altered.
1695 * New Python-based convenience functions:
1697 ** $_caller_is(name [, number_of_frames])
1698 ** $_caller_matches(regexp [, number_of_frames])
1699 ** $_any_caller_is(name [, number_of_frames])
1700 ** $_any_caller_matches(regexp [, number_of_frames])
1702 * GDB now supports the compilation and injection of source code into
1703 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1704 to compile the source code to object code, and if successful, inject
1705 and execute that code within the current context of the inferior.
1706 Currently the C language is supported. The commands used to
1707 interface with this new feature are:
1709 compile code [-raw|-r] [--] [source code]
1710 compile file [-raw|-r] filename
1714 demangle [-l language] [--] name
1715 Demangle "name" in the specified language, or the current language
1716 if elided. This command is renamed from the "maint demangle" command.
1717 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1718 as "maint demangler-warning".
1720 queue-signal signal-name-or-number
1721 Queue a signal to be delivered to the thread when it is resumed.
1723 add-auto-load-scripts-directory directory
1724 Add entries to the list of directories from which to load auto-loaded
1727 maint print user-registers
1728 List all currently available "user" registers.
1730 compile code [-r|-raw] [--] [source code]
1731 Compile, inject, and execute in the inferior the executable object
1732 code produced by compiling the provided source code.
1734 compile file [-r|-raw] filename
1735 Compile and inject into the inferior the executable object code
1736 produced by compiling the source code stored in the filename
1739 * On resume, GDB now always passes the signal the program had stopped
1740 for to the thread the signal was sent to, even if the user changed
1741 threads before resuming. Previously GDB would often (but not
1742 always) deliver the signal to the thread that happens to be current
1745 * Conversely, the "signal" command now consistently delivers the
1746 requested signal to the current thread. GDB now asks for
1747 confirmation if the program had stopped for a signal and the user
1748 switched threads meanwhile.
1750 * "breakpoint always-inserted" modes "off" and "auto" merged.
1752 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1753 won't remove breakpoints from the target until all threads stop,
1754 even in non-stop mode. The "auto" mode has been removed, and "off"
1755 is now the default mode.
1759 set debug symbol-lookup
1760 show debug symbol-lookup
1761 Control display of debugging info regarding symbol lookup.
1765 ** The -list-thread-groups command outputs an exit-code field for
1766 inferiors that have exited.
1770 MIPS SDE mips*-sde*-elf*
1774 Support for these obsolete configurations has been removed.
1776 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1777 SGI Irix-5.x mips-*-irix5*
1778 SGI Irix-6.x mips-*-irix6*
1779 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1780 VAX running Ultrix vax-*-ultrix*
1782 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1783 and "assf"), have been removed. Use the "sharedlibrary" command, or
1784 its alias "share", instead.
1786 *** Changes in GDB 7.8
1788 * New command line options
1791 This is an alias for the --data-directory option.
1793 * GDB supports printing and modifying of variable length automatic arrays
1794 as specified in ISO C99.
1796 * The ARM simulator now supports instruction level tracing
1797 with or without disassembly.
1801 GDB now has support for scripting using Guile. Whether this is
1802 available is determined at configure time.
1803 Guile version 2.0 or greater is required.
1804 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1806 * New commands (for set/show, see "New options" below)
1810 Invoke CODE by passing it to the Guile interpreter.
1814 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1816 info auto-load guile-scripts [regexp]
1817 Print the list of automatically loaded Guile scripts.
1819 * The source command is now capable of sourcing Guile scripts.
1820 This feature is dependent on the debugger being built with Guile support.
1824 set print symbol-loading (off|brief|full)
1825 show print symbol-loading
1826 Control whether to print informational messages when loading symbol
1827 information for a file. The default is "full", but when debugging
1828 programs with large numbers of shared libraries the amount of output
1829 becomes less useful.
1831 set guile print-stack (none|message|full)
1832 show guile print-stack
1833 Show a stack trace when an error is encountered in a Guile script.
1835 set auto-load guile-scripts (on|off)
1836 show auto-load guile-scripts
1837 Control auto-loading of Guile script files.
1839 maint ada set ignore-descriptive-types (on|off)
1840 maint ada show ignore-descriptive-types
1841 Control whether the debugger should ignore descriptive types in Ada
1842 programs. The default is not to ignore the descriptive types. See
1843 the user manual for more details on descriptive types and the intended
1844 usage of this option.
1846 set auto-connect-native-target
1848 Control whether GDB is allowed to automatically connect to the
1849 native target for the run, attach, etc. commands when not connected
1850 to any target yet. See also "target native" below.
1852 set record btrace replay-memory-access (read-only|read-write)
1853 show record btrace replay-memory-access
1854 Control what memory accesses are allowed during replay.
1856 maint set target-async (on|off)
1857 maint show target-async
1858 This controls whether GDB targets operate in synchronous or
1859 asynchronous mode. Normally the default is asynchronous, if it is
1860 available; but this can be changed to more easily debug problems
1861 occurring only in synchronous mode.
1863 set mi-async (on|off)
1865 Control whether MI asynchronous mode is preferred. This supersedes
1866 "set target-async" of previous GDB versions.
1868 * "set target-async" is deprecated as a CLI option and is now an alias
1869 for "set mi-async" (only puts MI into async mode).
1871 * Background execution commands (e.g., "c&", "s&", etc.) are now
1872 possible ``out of the box'' if the target supports them. Previously
1873 the user would need to explicitly enable the possibility with the
1874 "set target-async on" command.
1876 * New features in the GDB remote stub, GDBserver
1878 ** New option --debug-format=option1[,option2,...] allows one to add
1879 additional text to each output. At present only timestamps
1880 are supported: --debug-format=timestamps.
1881 Timestamps can also be turned on with the
1882 "monitor set debug-format timestamps" command from GDB.
1884 * The 'record instruction-history' command now starts counting instructions
1885 at one. This also affects the instruction ranges reported by the
1886 'record function-call-history' command when given the /i modifier.
1888 * The command 'record function-call-history' supports a new modifier '/c' to
1889 indent the function names based on their call stack depth.
1890 The fields for the '/i' and '/l' modifier have been reordered.
1891 The source line range is now prefixed with 'at'.
1892 The instruction range is now prefixed with 'inst'.
1893 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1894 "record instruction-history" and "list" commands.
1896 * The ranges given as arguments to the 'record function-call-history' and
1897 'record instruction-history' commands are now inclusive.
1899 * The btrace record target now supports the 'record goto' command.
1900 For locations inside the execution trace, the back trace is computed
1901 based on the information stored in the execution trace.
1903 * The btrace record target supports limited reverse execution and replay.
1904 The target does not record data and therefore does not allow reading
1905 memory or registers.
1907 * The "catch syscall" command now works on s390*-linux* targets.
1909 * The "compare-sections" command is no longer specific to target
1910 remote. It now works with all targets.
1912 * All native targets are now consistently called "native".
1913 Consequently, the "target child", "target GNU", "target djgpp",
1914 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1915 commands have been replaced with "target native". The QNX/NTO port
1916 leaves the "procfs" target in place and adds a "native" target for
1917 consistency with other ports. The impact on users should be minimal
1918 as these commands previously either throwed an error, or were
1919 no-ops. The target's name is visible in the output of the following
1920 commands: "help target", "info target", "info files", "maint print
1923 * The "target native" command now connects to the native target. This
1924 can be used to launch native programs even when "set
1925 auto-connect-native-target" is set to off.
1927 * GDB now supports access to Intel MPX registers on GNU/Linux.
1929 * Support for Intel AVX-512 registers on GNU/Linux.
1930 Support displaying and modifying Intel AVX-512 registers
1931 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1933 * New remote packets
1935 qXfer:btrace:read's annex
1936 The qXfer:btrace:read packet supports a new annex 'delta' to read
1937 branch trace incrementally.
1941 ** Valid Python operations on gdb.Value objects representing
1942 structs/classes invoke the corresponding overloaded operators if
1944 ** New `Xmethods' feature in the Python API. Xmethods are
1945 additional methods or replacements for existing methods of a C++
1946 class. This feature is useful for those cases where a method
1947 defined in C++ source code could be inlined or optimized out by
1948 the compiler, making it unavailable to GDB.
1951 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1953 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1954 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1955 its alias "share", instead.
1957 * The commands "set remotebaud" and "show remotebaud" are no longer
1958 supported. Use "set serial baud" and "show serial baud" (respectively)
1963 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1964 target-async". The latter is left as a deprecated alias of the
1965 former for backward compatibility. If the target supports it,
1966 CLI background execution commands are now always possible by
1967 default, independently of whether the frontend stated a
1968 preference for asynchronous execution with "-gdb-set mi-async".
1969 Previously "-gdb-set target-async off" affected both MI execution
1970 commands and CLI execution commands.
1972 *** Changes in GDB 7.7
1974 * Improved support for process record-replay and reverse debugging on
1975 arm*-linux* targets. Support for thumb32 and syscall instruction
1976 recording has been added.
1978 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1980 * GDB now supports Fission DWP file format version 2.
1981 http://gcc.gnu.org/wiki/DebugFission
1983 * New convenience function "$_isvoid", to check whether an expression
1984 is void. A void expression is an expression where the type of the
1985 result is "void". For example, some convenience variables may be
1986 "void" when evaluated (e.g., "$_exitcode" before the execution of
1987 the program being debugged; or an undefined convenience variable).
1988 Another example, when calling a function whose return type is
1991 * The "maintenance print objfiles" command now takes an optional regexp.
1993 * The "catch syscall" command now works on arm*-linux* targets.
1995 * GDB now consistently shows "<not saved>" when printing values of
1996 registers the debug info indicates have not been saved in the frame
1997 and there's nowhere to retrieve them from
1998 (callee-saved/call-clobbered registers):
2003 (gdb) info registers rax
2006 Before, the former would print "<optimized out>", and the latter
2007 "*value not available*".
2009 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2014 ** Frame filters and frame decorators have been added.
2015 ** Temporary breakpoints are now supported.
2016 ** Line tables representation has been added.
2017 ** New attribute 'parent_type' for gdb.Field objects.
2018 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2019 ** New attribute 'name' for gdb.Type objects.
2023 Nios II ELF nios2*-*-elf
2024 Nios II GNU/Linux nios2*-*-linux
2025 Texas Instruments MSP430 msp430*-*-elf
2027 * Removed native configurations
2029 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2030 been removed. ELF variants of these configurations are kept supported.
2032 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2033 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2034 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2035 i[34567]86-*-openbsd3.[0-3]
2036 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2037 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2038 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2042 Like "catch throw", but catches a re-thrown exception.
2043 maint check-psymtabs
2044 Renamed from old "maint check-symtabs".
2046 Perform consistency checks on symtabs.
2047 maint expand-symtabs
2048 Expand symtabs matching an optional regexp.
2051 Display the details of GDB configure-time options.
2053 maint set|show per-command
2054 maint set|show per-command space
2055 maint set|show per-command time
2056 maint set|show per-command symtab
2057 Enable display of per-command gdb resource usage.
2059 remove-symbol-file FILENAME
2060 remove-symbol-file -a ADDRESS
2061 Remove a symbol file added via add-symbol-file. The file to remove
2062 can be identified by its filename or by an address that lies within
2063 the boundaries of this symbol file in memory.
2066 info exceptions REGEXP
2067 Display the list of Ada exceptions defined in the program being
2068 debugged. If provided, only the exceptions whose names match REGEXP
2073 set debug symfile off|on
2075 Control display of debugging info regarding reading symbol files and
2076 symbol tables within those files
2078 set print raw frame-arguments
2079 show print raw frame-arguments
2080 Set/show whether to print frame arguments in raw mode,
2081 disregarding any defined pretty-printers.
2083 set remote trace-status-packet
2084 show remote trace-status-packet
2085 Set/show the use of remote protocol qTStatus packet.
2089 Control display of debugging messages related to Nios II targets.
2093 Control whether target-assisted range stepping is enabled.
2095 set startup-with-shell
2096 show startup-with-shell
2097 Specifies whether Unix child processes are started via a shell or
2102 Use the target memory cache for accesses to the code segment. This
2103 improves performance of remote debugging (particularly disassembly).
2105 * You can now use a literal value 'unlimited' for options that
2106 interpret 0 or -1 as meaning "unlimited". E.g., "set
2107 trace-buffer-size unlimited" is now an alias for "set
2108 trace-buffer-size -1" and "set height unlimited" is now an alias for
2111 * The "set debug symtab-create" debugging option of GDB has been changed to
2112 accept a verbosity level. 0 means "off", 1 provides basic debugging
2113 output, and values of 2 or greater provides more verbose output.
2115 * New command-line options
2117 Display the details of GDB configure-time options.
2119 * The command 'tsave' can now support new option '-ctf' to save trace
2120 buffer in Common Trace Format.
2122 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2125 * GDB now implements the the C++ 'typeid' operator.
2127 * The new convenience variable $_exception holds the exception being
2128 thrown or caught at an exception-related catchpoint.
2130 * The exception-related catchpoints, like "catch throw", now accept a
2131 regular expression which can be used to filter exceptions by type.
2133 * The new convenience variable $_exitsignal is automatically set to
2134 the terminating signal number when the program being debugged dies
2135 due to an uncaught signal.
2139 ** All MI commands now accept an optional "--language" option.
2140 Support for this feature can be verified by using the "-list-features"
2141 command, which should contain "language-option".
2143 ** The new command -info-gdb-mi-command allows the user to determine
2144 whether a GDB/MI command is supported or not.
2146 ** The "^error" result record returned when trying to execute an undefined
2147 GDB/MI command now provides a variable named "code" whose content is the
2148 "undefined-command" error code. Support for this feature can be verified
2149 by using the "-list-features" command, which should contain
2150 "undefined-command-error-code".
2152 ** The -trace-save MI command can optionally save trace buffer in Common
2155 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2157 ** The command -data-list-register-values now accepts an optional
2158 "--skip-unavailable" option. When used, only the available registers
2161 ** The new command -trace-frame-collected dumps collected variables,
2162 computed expressions, tvars, memory and registers in a traceframe.
2164 ** The commands -stack-list-locals, -stack-list-arguments and
2165 -stack-list-variables now accept an option "--skip-unavailable".
2166 When used, only the available locals or arguments are displayed.
2168 ** The -exec-run command now accepts an optional "--start" option.
2169 When used, the command follows the same semantics as the "start"
2170 command, stopping the program's execution at the start of its
2171 main subprogram. Support for this feature can be verified using
2172 the "-list-features" command, which should contain
2173 "exec-run-start-option".
2175 ** The new commands -catch-assert and -catch-exceptions insert
2176 catchpoints stopping the program when Ada exceptions are raised.
2178 ** The new command -info-ada-exceptions provides the equivalent of
2179 the new "info exceptions" command.
2181 * New system-wide configuration scripts
2182 A GDB installation now provides scripts suitable for use as system-wide
2183 configuration scripts for the following systems:
2187 * GDB now supports target-assigned range stepping with remote targets.
2188 This improves the performance of stepping source lines by reducing
2189 the number of control packets from/to GDB. See "New remote packets"
2192 * GDB now understands the element 'tvar' in the XML traceframe info.
2193 It has the id of the collected trace state variables.
2195 * On S/390 targets that provide the transactional-execution feature,
2196 the program interruption transaction diagnostic block (TDB) is now
2197 represented as a number of additional "registers" in GDB.
2199 * New remote packets
2203 The vCont packet supports a new 'r' action, that tells the remote
2204 stub to step through an address range itself, without GDB
2205 involvemement at each single-step.
2207 qXfer:libraries-svr4:read's annex
2208 The previously unused annex of the qXfer:libraries-svr4:read packet
2209 is now used to support passing an argument list. The remote stub
2210 reports support for this argument list to GDB's qSupported query.
2211 The defined arguments are "start" and "prev", used to reduce work
2212 necessary for library list updating, resulting in significant
2215 * New features in the GDB remote stub, GDBserver
2217 ** GDBserver now supports target-assisted range stepping. Currently
2218 enabled on x86/x86_64 GNU/Linux targets.
2220 ** GDBserver now adds element 'tvar' in the XML in the reply to
2221 'qXfer:traceframe-info:read'. It has the id of the collected
2222 trace state variables.
2224 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2227 * New 'z' formatter for printing and examining memory, this displays the
2228 value as hexadecimal zero padded on the left to the size of the type.
2230 * GDB can now use Windows x64 unwinding data.
2232 * The "set remotebaud" command has been replaced by "set serial baud".
2233 Similarly, "show remotebaud" has been replaced by "show serial baud".
2234 The "set remotebaud" and "show remotebaud" commands are still available
2235 to provide backward compatibility with older versions of GDB.
2237 *** Changes in GDB 7.6
2239 * Target record has been renamed to record-full.
2240 Record/replay is now enabled with the "record full" command.
2241 This also affects settings that are associated with full record/replay
2242 that have been moved from "set/show record" to "set/show record full":
2244 set|show record full insn-number-max
2245 set|show record full stop-at-limit
2246 set|show record full memory-query
2248 * A new record target "record-btrace" has been added. The new target
2249 uses hardware support to record the control-flow of a process. It
2250 does not support replaying the execution, but it implements the
2251 below new commands for investigating the recorded execution log.
2252 This new recording method can be enabled using:
2256 The "record-btrace" target is only available on Intel Atom processors
2257 and requires a Linux kernel 2.6.32 or later.
2259 * Two new commands have been added for record/replay to give information
2260 about the recorded execution without having to replay the execution.
2261 The commands are only supported by "record btrace".
2263 record instruction-history prints the execution history at
2264 instruction granularity
2266 record function-call-history prints the execution history at
2267 function granularity
2269 * New native configurations
2271 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2272 FreeBSD/powerpc powerpc*-*-freebsd
2273 x86_64/Cygwin x86_64-*-cygwin*
2274 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2278 ARM AArch64 aarch64*-*-elf
2279 ARM AArch64 GNU/Linux aarch64*-*-linux
2280 Lynx 178 PowerPC powerpc-*-lynx*178
2281 x86_64/Cygwin x86_64-*-cygwin*
2282 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2284 * If the configured location of system.gdbinit file (as given by the
2285 --with-system-gdbinit option at configure time) is in the
2286 data-directory (as specified by --with-gdb-datadir at configure
2287 time) or in one of its subdirectories, then GDB will look for the
2288 system-wide init file in the directory specified by the
2289 --data-directory command-line option.
2291 * New command line options:
2293 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2294 other initialization files, unlike -nx which disables all of them.
2296 * Removed command line options
2298 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2301 * The 'ptype' and 'whatis' commands now accept an argument to control
2304 * 'info proc' now works on some core files.
2308 ** Vectors can be created with gdb.Type.vector.
2310 ** Python's atexit.register now works in GDB.
2312 ** Types can be pretty-printed via a Python API.
2314 ** Python 3 is now supported (in addition to Python 2.4 or later)
2316 ** New class gdb.Architecture exposes GDB's internal representation
2317 of architecture in the Python API.
2319 ** New method Frame.architecture returns the gdb.Architecture object
2320 corresponding to the frame's architecture.
2322 * New Python-based convenience functions:
2324 ** $_memeq(buf1, buf2, length)
2325 ** $_streq(str1, str2)
2327 ** $_regex(str, regex)
2329 * The 'cd' command now defaults to using '~' (the home directory) if not
2332 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2333 default for GCC since November 2000.
2335 * The command 'forward-search' can now be abbreviated as 'fo'.
2337 * The command 'info tracepoints' can now display 'installed on target'
2338 or 'not installed on target' for each non-pending location of tracepoint.
2340 * New configure options
2342 --enable-libmcheck/--disable-libmcheck
2343 By default, development versions are built with -lmcheck on hosts
2344 that support it, in order to help track memory corruption issues.
2345 Release versions, on the other hand, are built without -lmcheck
2346 by default. The --enable-libmcheck/--disable-libmcheck configure
2347 options allow the user to override that default.
2348 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2349 This configure option allows the user to build GDB with
2350 libbabeltrace using which GDB can read Common Trace Format data.
2352 * New commands (for set/show, see "New options" below)
2355 Catch signals. This is similar to "handle", but allows commands and
2356 conditions to be attached.
2359 List the BFDs known to GDB.
2361 python-interactive [command]
2363 Start a Python interactive prompt, or evaluate the optional command
2364 and print the result of expressions.
2367 "py" is a new alias for "python".
2369 enable type-printer [name]...
2370 disable type-printer [name]...
2371 Enable or disable type printers.
2375 ** For the Renesas Super-H architecture, the "regs" command has been removed
2376 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2381 set print type methods (on|off)
2382 show print type methods
2383 Control whether method declarations are displayed by "ptype".
2384 The default is to show them.
2386 set print type typedefs (on|off)
2387 show print type typedefs
2388 Control whether typedef definitions are displayed by "ptype".
2389 The default is to show them.
2391 set filename-display basename|relative|absolute
2392 show filename-display
2393 Control the way in which filenames is displayed.
2394 The default is "relative", which preserves previous behavior.
2396 set trace-buffer-size
2397 show trace-buffer-size
2398 Request target to change the size of trace buffer.
2400 set remote trace-buffer-size-packet auto|on|off
2401 show remote trace-buffer-size-packet
2402 Control the use of the remote protocol `QTBuffer:size' packet.
2406 Control display of debugging messages related to ARM AArch64.
2409 set debug coff-pe-read
2410 show debug coff-pe-read
2411 Control display of debugging messages related to reading of COFF/PE
2416 Control display of debugging messages related to Mach-O symbols
2419 set debug notification
2420 show debug notification
2421 Control display of debugging info for async remote notification.
2425 ** Command parameter changes are now notified using new async record
2426 "=cmd-param-changed".
2427 ** Trace frame changes caused by command "tfind" are now notified using
2428 new async record "=traceframe-changed".
2429 ** The creation, deletion and modification of trace state variables
2430 are now notified using new async records "=tsv-created",
2431 "=tsv-deleted" and "=tsv-modified".
2432 ** The start and stop of process record are now notified using new
2433 async record "=record-started" and "=record-stopped".
2434 ** Memory changes are now notified using new async record
2436 ** The data-disassemble command response will include a "fullname" field
2437 containing the absolute file name when source has been requested.
2438 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2439 command, to allow pattern filling of memory areas.
2440 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2441 library load/unload events.
2442 ** The response to breakpoint commands and breakpoint async records
2443 includes an "installed" field containing a boolean state about each
2444 non-pending tracepoint location is whether installed on target or not.
2445 ** Output of the "-trace-status" command includes a "trace-file" field
2446 containing the name of the trace file being examined. This field is
2447 optional, and only present when examining a trace file.
2448 ** The "fullname" field is now always present along with the "file" field,
2449 even if the file cannot be found by GDB.
2451 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2452 You must have the LZMA library available when configuring GDB for this
2453 feature to be enabled. For more information, see:
2454 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2456 * New remote packets
2459 Set the size of trace buffer. The remote stub reports support for this
2460 packet to gdb's qSupported query.
2463 Enable Branch Trace Store (BTS)-based branch tracing for the current
2464 thread. The remote stub reports support for this packet to gdb's
2468 Disable branch tracing for the current thread. The remote stub reports
2469 support for this packet to gdb's qSupported query.
2472 Read the traced branches for the current thread. The remote stub
2473 reports support for this packet to gdb's qSupported query.
2475 *** Changes in GDB 7.5
2477 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2478 for more x32 ABI info.
2480 * GDB now supports access to MIPS DSP registers on Linux targets.
2482 * GDB now supports debugging microMIPS binaries.
2484 * The "info os" command on GNU/Linux can now display information on
2485 several new classes of objects managed by the operating system:
2486 "info os procgroups" lists process groups
2487 "info os files" lists file descriptors
2488 "info os sockets" lists internet-domain sockets
2489 "info os shm" lists shared-memory regions
2490 "info os semaphores" lists semaphores
2491 "info os msg" lists message queues
2492 "info os modules" lists loaded kernel modules
2494 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2495 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2496 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2497 options and inspect the probe arguments using the new $_probe_arg family
2498 of convenience variables. You can obtain more information about SystemTap
2499 in <http://sourceware.org/systemtap/>.
2501 * GDB now supports reversible debugging on ARM, it allows you to
2502 debug basic ARM and THUMB instructions, and provides
2503 record/replay support.
2505 * The option "symbol-reloading" has been deleted as it is no longer used.
2509 ** GDB commands implemented in Python can now be put in command class
2512 ** The "maint set python print-stack on|off" is now deleted.
2514 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2515 apply "flag enum"-style pretty-printing to any enum.
2517 ** gdb.lookup_symbol can now work when there is no current frame.
2519 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2520 the source at which the symbol was defined.
2522 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2523 method 'value'. The former indicates whether the symbol needs a
2524 frame in order to compute its value, and the latter computes the
2527 ** A new method 'referenced_value' on gdb.Value objects which can
2528 dereference pointer as well as C++ reference values.
2530 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2531 which return the global and static blocks (as gdb.Block objects),
2532 of the underlying symbol table, respectively.
2534 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2535 object associated with a PC value.
2537 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2538 of the address range occupied by code for the current source line.
2540 * Go language support.
2541 GDB now supports debugging programs written in the Go programming
2544 * GDBserver now supports stdio connections.
2545 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2547 * The binary "gdbtui" can no longer be built or installed.
2548 Use "gdb -tui" instead.
2550 * GDB will now print "flag" enums specially. A flag enum is one where
2551 all the enumerator values have no bits in common when pairwise
2552 "and"ed. When printing a value whose type is a flag enum, GDB will
2553 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2554 (gdb) print (enum E) 3
2557 * The filename part of a linespec will now match trailing components
2558 of a source file name. For example, "break gcc/expr.c:1000" will
2559 now set a breakpoint in build/gcc/expr.c, but not
2560 build/libcpp/expr.c.
2562 * The "info proc" and "generate-core-file" commands will now also
2563 work on remote targets connected to GDBserver on Linux.
2565 * The command "info catch" has been removed. It has been disabled
2566 since December 2007.
2568 * The "catch exception" and "catch assert" commands now accept
2569 a condition at the end of the command, much like the "break"
2570 command does. For instance:
2572 (gdb) catch exception Constraint_Error if Barrier = True
2574 Previously, it was possible to add a condition to such catchpoints,
2575 but it had to be done as a second step, after the catchpoint had been
2576 created, using the "condition" command.
2578 * The "info static-tracepoint-marker" command will now also work on
2579 native Linux targets with in-process agent.
2581 * GDB can now set breakpoints on inlined functions.
2583 * The .gdb_index section has been updated to include symbols for
2584 inlined functions. GDB will ignore older .gdb_index sections by
2585 default, which could cause symbol files to be loaded more slowly
2586 until their .gdb_index sections can be recreated. The new command
2587 "set use-deprecated-index-sections on" will cause GDB to use any older
2588 .gdb_index sections it finds. This will restore performance, but the
2589 ability to set breakpoints on inlined functions will be lost in symbol
2590 files with older .gdb_index sections.
2592 The .gdb_index section has also been updated to record more information
2593 about each symbol. This speeds up the "info variables", "info functions"
2594 and "info types" commands when used with programs having the .gdb_index
2595 section, as well as speeding up debugging with shared libraries using
2596 the .gdb_index section.
2598 * Ada support for GDB/MI Variable Objects has been added.
2600 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2605 ** New command -info-os is the MI equivalent of "info os".
2607 ** Output logs ("set logging" and related) now include MI output.
2611 ** "set use-deprecated-index-sections on|off"
2612 "show use-deprecated-index-sections on|off"
2613 Controls the use of deprecated .gdb_index sections.
2615 ** "catch load" and "catch unload" can be used to stop when a shared
2616 library is loaded or unloaded, respectively.
2618 ** "enable count" can be used to auto-disable a breakpoint after
2621 ** "info vtbl" can be used to show the virtual method tables for
2622 C++ and Java objects.
2624 ** "explore" and its sub commands "explore value" and "explore type"
2625 can be used to recursively explore values and types of
2626 expressions. These commands are available only if GDB is
2627 configured with '--with-python'.
2629 ** "info auto-load" shows status of all kinds of auto-loaded files,
2630 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2631 sequences of commands files, "info auto-load python-scripts"
2632 shows status of auto-loading Python script files,
2633 "info auto-load local-gdbinit" shows status of loading init file
2634 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2635 status of inferior specific thread debugging shared library loading.
2637 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2638 and "show auto-load-scripts" commands have been deprecated, use their
2639 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2640 and "show auto-load python-scripts" counterparts instead.
2642 ** "dprintf location,format,args..." creates a dynamic printf, which
2643 is basically a breakpoint that does a printf and immediately
2644 resumes your program's execution, so it is like a printf that you
2645 can insert dynamically at runtime instead of at compiletime.
2647 ** "set print symbol"
2649 Controls whether GDB attempts to display the symbol, if any,
2650 corresponding to addresses it prints. This defaults to "on", but
2651 you can set it to "off" to restore GDB's previous behavior.
2653 * Deprecated commands
2655 ** For the Renesas Super-H architecture, the "regs" command has been
2656 deprecated, and "info all-registers" should be used instead.
2660 Renesas RL78 rl78-*-elf
2661 HP OpenVMS ia64 ia64-hp-openvms*
2663 * GDBserver supports evaluation of breakpoint conditions. When
2664 support is advertised by GDBserver, GDB may be told to send the
2665 breakpoint conditions in bytecode form to GDBserver. GDBserver
2666 will only report the breakpoint trigger to GDB when its condition
2671 set mips compression
2672 show mips compression
2673 Select the compressed ISA encoding used in functions that have no symbol
2674 information available. The encoding can be set to either of:
2677 and is updated automatically from ELF file flags if available.
2679 set breakpoint condition-evaluation
2680 show breakpoint condition-evaluation
2681 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2682 GDBserver ("target"). Default option "auto" chooses the most efficient
2684 This option can improve debugger efficiency depending on the speed of the
2688 Disable auto-loading globally.
2691 Show auto-loading setting of all kinds of auto-loaded files.
2693 set auto-load gdb-scripts on|off
2694 show auto-load gdb-scripts
2695 Control auto-loading of GDB canned sequences of commands files.
2697 set auto-load python-scripts on|off
2698 show auto-load python-scripts
2699 Control auto-loading of Python script files.
2701 set auto-load local-gdbinit on|off
2702 show auto-load local-gdbinit
2703 Control loading of init file (.gdbinit) from current directory.
2705 set auto-load libthread-db on|off
2706 show auto-load libthread-db
2707 Control auto-loading of inferior specific thread debugging shared library.
2709 set auto-load scripts-directory <dir1>[:<dir2>...]
2710 show auto-load scripts-directory
2711 Set a list of directories from which to load auto-loaded scripts.
2712 Automatically loaded Python scripts and GDB scripts are located in one
2713 of the directories listed by this option.
2714 The delimiter (':' above) may differ according to the host platform.
2716 set auto-load safe-path <dir1>[:<dir2>...]
2717 show auto-load safe-path
2718 Set a list of directories from which it is safe to auto-load files.
2719 The delimiter (':' above) may differ according to the host platform.
2721 set debug auto-load on|off
2722 show debug auto-load
2723 Control display of debugging info for auto-loading the files above.
2725 set dprintf-style gdb|call|agent
2727 Control the way in which a dynamic printf is performed; "gdb"
2728 requests a GDB printf command, while "call" causes dprintf to call a
2729 function in the inferior. "agent" requests that the target agent
2730 (such as GDBserver) do the printing.
2732 set dprintf-function <expr>
2733 show dprintf-function
2734 set dprintf-channel <expr>
2735 show dprintf-channel
2736 Set the function and optional first argument to the call when using
2737 the "call" style of dynamic printf.
2739 set disconnected-dprintf on|off
2740 show disconnected-dprintf
2741 Control whether agent-style dynamic printfs continue to be in effect
2742 after GDB disconnects.
2744 * New configure options
2746 --with-auto-load-dir
2747 Configure default value for the 'set auto-load scripts-directory'
2748 setting above. It defaults to '$debugdir:$datadir/auto-load',
2749 $debugdir representing global debugging info directories (available
2750 via 'show debug-file-directory') and $datadir representing GDB's data
2751 directory (available via 'show data-directory').
2753 --with-auto-load-safe-path
2754 Configure default value for the 'set auto-load safe-path' setting
2755 above. It defaults to the --with-auto-load-dir setting.
2757 --without-auto-load-safe-path
2758 Set 'set auto-load safe-path' to '/', effectively disabling this
2761 * New remote packets
2763 z0/z1 conditional breakpoints extension
2765 The z0/z1 breakpoint insertion packets have been extended to carry
2766 a list of conditional expressions over to the remote stub depending on the
2767 condition evaluation mode. The use of this extension can be controlled
2768 via the "set remote conditional-breakpoints-packet" command.
2772 Specify the signals which the remote stub may pass to the debugged
2773 program without GDB involvement.
2775 * New command line options
2777 --init-command=FILE, -ix Like --command, -x but execute it
2778 before loading inferior.
2779 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2780 execute it before loading inferior.
2782 *** Changes in GDB 7.4
2784 * GDB now handles ambiguous linespecs more consistently; the existing
2785 FILE:LINE support has been expanded to other types of linespecs. A
2786 breakpoint will now be set on all matching locations in all
2787 inferiors, and locations will be added or removed according to
2790 * GDB now allows you to skip uninteresting functions and files when
2791 stepping with the "skip function" and "skip file" commands.
2793 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2794 and "show remote hardware-watchpoint-length-limit". These allows to
2795 set or show the maximum length limit (in bytes) of a remote
2796 target hardware watchpoint.
2798 This allows e.g. to use "unlimited" hardware watchpoints with the
2799 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2800 watchpoints are slower than real hardware watchpoints but are
2801 significantly faster than gdb software watchpoints.
2805 ** The register_pretty_printer function in module gdb.printing now takes
2806 an optional `replace' argument. If True, the new printer replaces any
2809 ** The "maint set python print-stack on|off" command has been
2810 deprecated and will be deleted in GDB 7.5.
2811 A new command: "set python print-stack none|full|message" has
2812 replaced it. Additionally, the default for "print-stack" is
2813 now "message", which just prints the error message without
2816 ** A prompt substitution hook (prompt_hook) is now available to the
2819 ** A new Python module, gdb.prompt has been added to the GDB Python
2820 modules library. This module provides functionality for
2821 escape sequences in prompts (used by set/show
2822 extended-prompt). These escape sequences are replaced by their
2823 corresponding value.
2825 ** Python commands and convenience-functions located in
2826 'data-directory'/python/gdb/command and
2827 'data-directory'/python/gdb/function are now automatically loaded
2830 ** Blocks now provide four new attributes. global_block and
2831 static_block will return the global and static blocks
2832 respectively. is_static and is_global are boolean attributes
2833 that indicate if the block is one of those two types.
2835 ** Symbols now provide the "type" attribute, the type of the symbol.
2837 ** The "gdb.breakpoint" function has been deprecated in favor of
2840 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2841 of a function. This class is based on the "finish" command
2842 available in the CLI.
2844 ** Type objects for struct and union types now allow access to
2845 the fields using standard Python dictionary (mapping) methods.
2846 For example, "some_type['myfield']" now works, as does
2847 "some_type.items()".
2849 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2852 ** A new function, "deep_items" has been added to the gdb.types
2853 module in the GDB Python modules library. This function returns
2854 an iterator over the fields of a struct or union type. Unlike
2855 the standard Python "iteritems" method, it will recursively traverse
2856 any anonymous fields.
2860 ** "*stopped" events can report several new "reason"s, such as
2863 ** Breakpoint changes are now notified using new async records, like
2864 "=breakpoint-modified".
2866 ** New command -ada-task-info.
2868 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2869 $sdir specifies the default system locations of shared libraries.
2870 $pdir specifies the directory where the libpthread used by the application
2873 GDB no longer looks in $sdir and $pdir after it has searched the directories
2874 mentioned in libthread-db-search-path. If you want to search those
2875 directories, they must be specified in libthread-db-search-path.
2876 The default value of libthread-db-search-path on GNU/Linux and Solaris
2877 systems is now "$sdir:$pdir".
2879 $pdir is not supported by gdbserver, it is currently ignored.
2880 $sdir is supported by gdbserver.
2882 * New configure option --with-iconv-bin.
2883 When using the internationalization support like the one in the GNU C
2884 library, GDB will invoke the "iconv" program to get a list of supported
2885 character sets. If this program lives in a non-standard location, one can
2886 use this option to specify where to find it.
2888 * When natively debugging programs on PowerPC BookE processors running
2889 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2890 watchpoints, which specify a mask in addition to an address to watch.
2891 The mask specifies that some bits of an address (the bits which are
2892 reset in the mask) should be ignored when matching the address accessed
2893 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2894 section in the user manual for more details.
2896 * The new option --once causes GDBserver to stop listening for connections once
2897 the first connection is made. The listening port used by GDBserver will
2898 become available after that.
2900 * New commands "info macros" and "alias" have been added.
2902 * New function parameters suffix @entry specifies value of function parameter
2903 at the time the function got called. Entry values are available only since
2909 "!" is now an alias of the "shell" command.
2910 Note that no space is needed between "!" and SHELL COMMAND.
2914 watch EXPRESSION mask MASK_VALUE
2915 The watch command now supports the mask argument which allows creation
2916 of masked watchpoints, if the current architecture supports this feature.
2918 info auto-load-scripts [REGEXP]
2919 This command was formerly named "maintenance print section-scripts".
2920 It is now generally useful and is no longer a maintenance-only command.
2922 info macro [-all] [--] MACRO
2923 The info macro command has new options `-all' and `--'. The first for
2924 printing all definitions of a macro. The second for explicitly specifying
2925 the end of arguments and the beginning of the macro name in case the macro
2926 name starts with a hyphen.
2928 collect[/s] EXPRESSIONS
2929 The tracepoint collect command now takes an optional modifier "/s"
2930 that directs it to dereference pointer-to-character types and
2931 collect the bytes of memory up to a zero byte. The behavior is
2932 similar to what you see when you use the regular print command on a
2933 string. An optional integer following the "/s" sets a bound on the
2934 number of bytes that will be collected.
2937 The trace start command now interprets any supplied arguments as a
2938 note to be recorded with the trace run, with an effect similar to
2939 setting the variable trace-notes.
2942 The trace stop command now interprets any arguments as a note to be
2943 mentioned along with the tstatus report that the trace was stopped
2944 with a command. The effect is similar to setting the variable
2947 * Tracepoints can now be enabled and disabled at any time after a trace
2948 experiment has been started using the standard "enable" and "disable"
2949 commands. It is now possible to start a trace experiment with no enabled
2950 tracepoints; GDB will display a warning, but will allow the experiment to
2951 begin, assuming that tracepoints will be enabled as needed while the trace
2954 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2955 locations with 4-byte instructions, when they were previously
2956 limited to locations with instructions of 5 bytes or longer.
2960 set debug dwarf2-read
2961 show debug dwarf2-read
2962 Turns on or off display of debugging messages related to reading
2963 DWARF debug info. The default is off.
2965 set debug symtab-create
2966 show debug symtab-create
2967 Turns on or off display of debugging messages related to symbol table
2968 creation. The default is off.
2971 show extended-prompt
2972 Set the GDB prompt, and allow escape sequences to be inserted to
2973 display miscellaneous information (see 'help set extended-prompt'
2974 for the list of sequences). This prompt (and any information
2975 accessed through the escape sequences) is updated every time the
2976 prompt is displayed.
2978 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2979 show print entry-values
2980 Set printing of frame argument values at function entry. In some cases
2981 GDB can determine the value of function argument which was passed by the
2982 function caller, even if the value was modified inside the called function.
2984 set debug entry-values
2985 show debug entry-values
2986 Control display of debugging info for determining frame argument values at
2987 function entry and virtual tail call frames.
2989 set basenames-may-differ
2990 show basenames-may-differ
2991 Set whether a source file may have multiple base names.
2992 (A "base name" is the name of a file with the directory part removed.
2993 Example: The base name of "/home/user/hello.c" is "hello.c".)
2994 If set, GDB will canonicalize file names (e.g., expand symlinks)
2995 before comparing them. Canonicalization is an expensive operation,
2996 but it allows the same file be known by more than one base name.
2997 If not set (the default), all source files are assumed to have just
2998 one base name, and gdb will do file name comparisons more efficiently.
3004 Set a user name and notes for the current and any future trace runs.
3005 This is useful for long-running and/or disconnected traces, to
3006 inform others (or yourself) as to who is running the trace, supply
3007 contact information, or otherwise explain what is going on.
3009 set trace-stop-notes
3010 show trace-stop-notes
3011 Set a note attached to the trace run, that is displayed when the
3012 trace has been stopped by a tstop command. This is useful for
3013 instance as an explanation, if you are stopping a trace run that was
3014 started by someone else.
3016 * New remote packets
3020 Dynamically enable a tracepoint in a started trace experiment.
3024 Dynamically disable a tracepoint in a started trace experiment.
3028 Set the user and notes of the trace run.
3032 Query the current status of a tracepoint.
3036 Query the minimum length of instruction at which a fast tracepoint may
3039 * Dcache size (number of lines) and line-size are now runtime-configurable
3040 via "set dcache line" and "set dcache line-size" commands.
3044 Texas Instruments TMS320C6x tic6x-*-*
3048 Renesas RL78 rl78-*-elf
3050 *** Changes in GDB 7.3.1
3052 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3054 *** Changes in GDB 7.3
3056 * GDB has a new command: "thread find [REGEXP]".
3057 It finds the thread id whose name, target id, or thread extra info
3058 matches the given regular expression.
3060 * The "catch syscall" command now works on mips*-linux* targets.
3062 * The -data-disassemble MI command now supports modes 2 and 3 for
3063 dumping the instruction opcodes.
3065 * New command line options
3067 -data-directory DIR Specify DIR as the "data-directory".
3068 This is mostly for testing purposes.
3070 * The "maint set python auto-load on|off" command has been renamed to
3071 "set auto-load-scripts on|off".
3073 * GDB has a new command: "set directories".
3074 It is like the "dir" command except that it replaces the
3075 source path list instead of augmenting it.
3077 * GDB now understands thread names.
3079 On GNU/Linux, "info threads" will display the thread name as set by
3080 prctl or pthread_setname_np.
3082 There is also a new command, "thread name", which can be used to
3083 assign a name internally for GDB to display.
3086 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3087 has been integrated into GDB.
3091 ** The function gdb.Write now accepts an optional keyword 'stream'.
3092 This keyword, when provided, will direct the output to either
3093 stdout, stderr, or GDB's logging output.
3095 ** Parameters can now be be sub-classed in Python, and in particular
3096 you may implement the get_set_doc and get_show_doc functions.
3097 This improves how Parameter set/show documentation is processed
3098 and allows for more dynamic content.
3100 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3101 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3102 have an is_valid method.
3104 ** Breakpoints can now be sub-classed in Python, and in particular
3105 you may implement a 'stop' function that is executed each time
3106 the inferior reaches that breakpoint.
3108 ** New function gdb.lookup_global_symbol looks up a global symbol.
3110 ** GDB values in Python are now callable if the value represents a
3111 function. For example, if 'some_value' represents a function that
3112 takes two integer parameters and returns a value, you can call
3113 that function like so:
3115 result = some_value (10,20)
3117 ** Module gdb.types has been added.
3118 It contains a collection of utilities for working with gdb.Types objects:
3119 get_basic_type, has_field, make_enum_dict.
3121 ** Module gdb.printing has been added.
3122 It contains utilities for writing and registering pretty-printers.
3123 New classes: PrettyPrinter, SubPrettyPrinter,
3124 RegexpCollectionPrettyPrinter.
3125 New function: register_pretty_printer.
3127 ** New commands "info pretty-printers", "enable pretty-printer" and
3128 "disable pretty-printer" have been added.
3130 ** gdb.parameter("directories") is now available.
3132 ** New function gdb.newest_frame returns the newest frame in the
3135 ** The gdb.InferiorThread class has a new "name" attribute. This
3136 holds the thread's name.
3138 ** Python Support for Inferior events.
3139 Python scripts can add observers to be notified of events
3140 occurring in the process being debugged.
3141 The following events are currently supported:
3142 - gdb.events.cont Continue event.
3143 - gdb.events.exited Inferior exited event.
3144 - gdb.events.stop Signal received, and Breakpoint hit events.
3148 ** GDB now puts template parameters in scope when debugging in an
3149 instantiation. For example, if you have:
3151 template<int X> int func (void) { return X; }
3153 then if you step into func<5>, "print X" will show "5". This
3154 feature requires proper debuginfo support from the compiler; it
3155 was added to GCC 4.5.
3157 ** The motion commands "next", "finish", "until", and "advance" now
3158 work better when exceptions are thrown. In particular, GDB will
3159 no longer lose control of the inferior; instead, the GDB will
3160 stop the inferior at the point at which the exception is caught.
3161 This functionality requires a change in the exception handling
3162 code that was introduced in GCC 4.5.
3164 * GDB now follows GCC's rules on accessing volatile objects when
3165 reading or writing target state during expression evaluation.
3166 One notable difference to prior behavior is that "print x = 0"
3167 no longer generates a read of x; the value of the assignment is
3168 now always taken directly from the value being assigned.
3170 * GDB now has some support for using labels in the program's source in
3171 linespecs. For instance, you can use "advance label" to continue
3172 execution to a label.
3174 * GDB now has support for reading and writing a new .gdb_index
3175 section. This section holds a fast index of DWARF debugging
3176 information and can be used to greatly speed up GDB startup and
3177 operation. See the documentation for `save gdb-index' for details.
3179 * The "watch" command now accepts an optional "-location" argument.
3180 When used, this causes GDB to watch the memory referred to by the
3181 expression. Such a watchpoint is never deleted due to it going out
3184 * GDB now supports thread debugging of core dumps on GNU/Linux.
3186 GDB now activates thread debugging using the libthread_db library
3187 when debugging GNU/Linux core dumps, similarly to when debugging
3188 live processes. As a result, when debugging a core dump file, GDB
3189 is now able to display pthread_t ids of threads. For example, "info
3190 threads" shows the same output as when debugging the process when it
3191 was live. In earlier releases, you'd see something like this:
3194 * 1 LWP 6780 main () at main.c:10
3196 While now you see this:
3199 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3201 It is also now possible to inspect TLS variables when debugging core
3204 When debugging a core dump generated on a machine other than the one
3205 used to run GDB, you may need to point GDB at the correct
3206 libthread_db library with the "set libthread-db-search-path"
3207 command. See the user manual for more details on this command.
3209 * When natively debugging programs on PowerPC BookE processors running
3210 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3211 which stop execution of the inferior whenever it executes an instruction
3212 at any address within the specified range. See the "PowerPC Embedded"
3213 section in the user manual for more details.
3215 * New features in the GDB remote stub, GDBserver
3217 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3218 and i686 LynxOS (version 5.x).
3220 ** GDBserver is now supported on Blackfin Linux.
3222 * New native configurations
3224 ia64 HP-UX ia64-*-hpux*
3228 Analog Devices, Inc. Blackfin Processor bfin-*
3230 * Ada task switching is now supported on sparc-elf targets when
3231 debugging a program using the Ravenscar Profile. For more information,
3232 see the "Tasking Support when using the Ravenscar Profile" section
3233 in the GDB user manual.
3235 * Guile support was removed.
3237 * New features in the GNU simulator
3239 ** The --map-info flag lists all known core mappings.
3241 ** CFI flashes may be simulated via the "cfi" device.
3243 *** Changes in GDB 7.2
3245 * Shared library support for remote targets by default
3247 When GDB is configured for a generic, non-OS specific target, like
3248 for example, --target=arm-eabi or one of the many *-*-elf targets,
3249 GDB now queries remote stubs for loaded shared libraries using the
3250 `qXfer:libraries:read' packet. Previously, shared library support
3251 was always disabled for such configurations.
3255 ** Argument Dependent Lookup (ADL)
3257 In C++ ADL lookup directs function search to the namespaces of its
3258 arguments even if the namespace has not been imported.
3268 Here the compiler will search for `foo' in the namespace of 'b'
3269 and find A::foo. GDB now supports this. This construct is commonly
3270 used in the Standard Template Library for operators.
3272 ** Improved User Defined Operator Support
3274 In addition to member operators, GDB now supports lookup of operators
3275 defined in a namespace and imported with a `using' directive, operators
3276 defined in the global scope, operators imported implicitly from an
3277 anonymous namespace, and the ADL operators mentioned in the previous
3279 GDB now also supports proper overload resolution for all the previously
3280 mentioned flavors of operators.
3282 ** static const class members
3284 Printing of static const class members that are initialized in the
3285 class definition has been fixed.
3287 * Windows Thread Information Block access.
3289 On Windows targets, GDB now supports displaying the Windows Thread
3290 Information Block (TIB) structure. This structure is visible either
3291 by using the new command `info w32 thread-information-block' or, by
3292 dereferencing the new convenience variable named `$_tlb', a
3293 thread-specific pointer to the TIB. This feature is also supported
3294 when remote debugging using GDBserver.
3296 * Static tracepoints
3298 Static tracepoints are calls in the user program into a tracing
3299 library. One such library is a port of the LTTng kernel tracer to
3300 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3301 When debugging with GDBserver, GDB now supports combining the GDB
3302 tracepoint machinery with such libraries. For example: the user can
3303 use GDB to probe a static tracepoint marker (a call from the user
3304 program into the tracing library) with the new "strace" command (see
3305 "New commands" below). This creates a "static tracepoint" in the
3306 breakpoint list, that can be manipulated with the same feature set
3307 as fast and regular tracepoints. E.g., collect registers, local and
3308 global variables, collect trace state variables, and define
3309 tracepoint conditions. In addition, the user can collect extra
3310 static tracepoint marker specific data, by collecting the new
3311 $_sdata internal variable. When analyzing the trace buffer, you can
3312 inspect $_sdata like any other variable available to GDB. For more
3313 information, see the "Tracepoints" chapter in GDB user manual. New
3314 remote packets have been defined to support static tracepoints, see
3315 the "New remote packets" section below.
3317 * Better reconstruction of tracepoints after disconnected tracing
3319 GDB will attempt to download the original source form of tracepoint
3320 definitions when starting a trace run, and then will upload these
3321 upon reconnection to the target, resulting in a more accurate
3322 reconstruction of the tracepoints that are in use on the target.
3326 You can now exercise direct control over the ways that GDB can
3327 affect your program. For instance, you can disallow the setting of
3328 breakpoints, so that the program can run continuously (assuming
3329 non-stop mode). In addition, the "observer" variable is available
3330 to switch all of the different controls; in observer mode, GDB
3331 cannot affect the target's behavior at all, which is useful for
3332 tasks like diagnosing live systems in the field.
3334 * The new convenience variable $_thread holds the number of the
3337 * New remote packets
3341 Return the address of the Windows Thread Information Block of a given thread.
3345 In response to several of the tracepoint packets, the target may now
3346 also respond with a number of intermediate `qRelocInsn' request
3347 packets before the final result packet, to have GDB handle
3348 relocating an instruction to execute at a different address. This
3349 is particularly useful for stubs that support fast tracepoints. GDB
3350 reports support for this feature in the qSupported packet.
3354 List static tracepoint markers in the target program.
3358 List static tracepoint markers at a given address in the target
3361 qXfer:statictrace:read
3363 Read the static trace data collected (by a `collect $_sdata'
3364 tracepoint action). The remote stub reports support for this packet
3365 to gdb's qSupported query.
3369 Send the current settings of GDB's permission flags.
3373 Send part of the source (textual) form of a tracepoint definition,
3374 which includes location, conditional, and action list.
3376 * The source command now accepts a -s option to force searching for the
3377 script in the source search path even if the script name specifies
3380 * New features in the GDB remote stub, GDBserver
3382 - GDBserver now support tracepoints (including fast tracepoints, and
3383 static tracepoints). The feature is currently supported by the
3384 i386-linux and amd64-linux builds. See the "Tracepoints support
3385 in gdbserver" section in the manual for more information.
3387 GDBserver JIT compiles the tracepoint's conditional agent
3388 expression bytecode into native code whenever possible for low
3389 overhead dynamic tracepoints conditionals. For such tracepoints,
3390 an expression that examines program state is evaluated when the
3391 tracepoint is reached, in order to determine whether to capture
3392 trace data. If the condition is simple and false, processing the
3393 tracepoint finishes very quickly and no data is gathered.
3395 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3396 for static tracepoints support.
3398 - GDBserver now supports x86_64 Windows 64-bit debugging.
3400 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3401 it understands register description.
3403 * The --batch flag now disables pagination and queries.
3405 * X86 general purpose registers
3407 GDB now supports reading/writing byte, word and double-word x86
3408 general purpose registers directly. This means you can use, say,
3409 $ah or $ax to refer, respectively, to the byte register AH and
3410 16-bit word register AX that are actually portions of the 32-bit
3411 register EAX or 64-bit register RAX.
3413 * The `commands' command now accepts a range of breakpoints to modify.
3414 A plain `commands' following a command that creates multiple
3415 breakpoints affects all the breakpoints set by that command. This
3416 applies to breakpoints set by `rbreak', and also applies when a
3417 single `break' command creates multiple breakpoints (e.g.,
3418 breakpoints on overloaded c++ functions).
3420 * The `rbreak' command now accepts a filename specification as part of
3421 its argument, limiting the functions selected by the regex to those
3422 in the specified file.
3424 * Support for remote debugging Windows and SymbianOS shared libraries
3425 from Unix hosts has been improved. Non Windows GDB builds now can
3426 understand target reported file names that follow MS-DOS based file
3427 system semantics, such as file names that include drive letters and
3428 use the backslash character as directory separator. This makes it
3429 possible to transparently use the "set sysroot" and "set
3430 solib-search-path" on Unix hosts to point as host copies of the
3431 target's shared libraries. See the new command "set
3432 target-file-system-kind" described below, and the "Commands to
3433 specify files" section in the user manual for more information.
3437 eval template, expressions...
3438 Convert the values of one or more expressions under the control
3439 of the string template to a command line, and call it.
3441 set target-file-system-kind unix|dos-based|auto
3442 show target-file-system-kind
3443 Set or show the assumed file system kind for target reported file
3446 save breakpoints <filename>
3447 Save all current breakpoint definitions to a file suitable for use
3448 in a later debugging session. To read the saved breakpoint
3449 definitions, use the `source' command.
3451 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3454 info static-tracepoint-markers
3455 Display information about static tracepoint markers in the target.
3457 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3458 Define a static tracepoint by probing a marker at the given
3459 function, line, address, or marker ID.
3463 Enable and disable observer mode.
3465 set may-write-registers on|off
3466 set may-write-memory on|off
3467 set may-insert-breakpoints on|off
3468 set may-insert-tracepoints on|off
3469 set may-insert-fast-tracepoints on|off
3470 set may-interrupt on|off
3471 Set individual permissions for GDB effects on the target. Note that
3472 some of these settings can have undesirable or surprising
3473 consequences, particularly when changed in the middle of a session.
3474 For instance, disabling the writing of memory can prevent
3475 breakpoints from being inserted, cause single-stepping to fail, or
3476 even crash your program, if you disable after breakpoints have been
3477 inserted. However, GDB should not crash.
3479 set record memory-query on|off
3480 show record memory-query
3481 Control whether to stop the inferior if memory changes caused
3482 by an instruction cannot be recorded.
3487 The disassemble command now supports "start,+length" form of two arguments.
3491 ** GDB now provides a new directory location, called the python directory,
3492 where Python scripts written for GDB can be installed. The location
3493 of that directory is <data-directory>/python, where <data-directory>
3494 is the GDB data directory. For more details, see section `Scripting
3495 GDB using Python' in the manual.
3497 ** The GDB Python API now has access to breakpoints, symbols, symbol
3498 tables, program spaces, inferiors, threads and frame's code blocks.
3499 Additionally, GDB Parameters can now be created from the API, and
3500 manipulated via set/show in the CLI.
3502 ** New functions gdb.target_charset, gdb.target_wide_charset,
3503 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3505 ** New exception gdb.GdbError.
3507 ** Pretty-printers are now also looked up in the current program space.
3509 ** Pretty-printers can now be individually enabled and disabled.
3511 ** GDB now looks for names of Python scripts to auto-load in a
3512 special section named `.debug_gdb_scripts', in addition to looking
3513 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3515 * Tracepoint actions were unified with breakpoint commands. In particular,
3516 there are no longer differences in "info break" output for breakpoints and
3517 tracepoints and the "commands" command can be used for both tracepoints and
3518 regular breakpoints.
3522 ARM Symbian arm*-*-symbianelf*
3524 * D language support.
3525 GDB now supports debugging programs written in the D programming
3528 * GDB now supports the extended ptrace interface for PowerPC which is
3529 available since Linux kernel version 2.6.34. This automatically enables
3530 any hardware breakpoints and additional hardware watchpoints available in
3531 the processor. The old ptrace interface exposes just one hardware
3532 watchpoint and no hardware breakpoints.
3534 * GDB is now able to use the Data Value Compare (DVC) register available on
3535 embedded PowerPC processors to implement in hardware simple watchpoint
3536 conditions of the form:
3538 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3540 This works in native GDB running on Linux kernels with the extended ptrace
3541 interface mentioned above.
3543 *** Changes in GDB 7.1
3547 ** Namespace Support
3549 GDB now supports importing of namespaces in C++. This enables the
3550 user to inspect variables from imported namespaces. Support for
3551 namepace aliasing has also been added. So, if a namespace is
3552 aliased in the current scope (e.g. namepace C=A; ) the user can
3553 print variables using the alias (e.g. (gdb) print C::x).
3557 All known bugs relating to the printing of virtual base class were
3558 fixed. It is now possible to call overloaded static methods using a
3563 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3564 and reinterpret_cast<> are now handled by the C++ expression parser.
3568 Xilinx MicroBlaze microblaze-*-*
3573 Xilinx MicroBlaze microblaze
3576 * Multi-program debugging.
3578 GDB now has support for multi-program (a.k.a. multi-executable or
3579 multi-exec) debugging. This allows for debugging multiple inferiors
3580 simultaneously each running a different program under the same GDB
3581 session. See "Debugging Multiple Inferiors and Programs" in the
3582 manual for more information. This implied some user visible changes
3583 in the multi-inferior support. For example, "info inferiors" now
3584 lists inferiors that are not running yet or that have exited
3585 already. See also "New commands" and "New options" below.
3587 * New tracing features
3589 GDB's tracepoint facility now includes several new features:
3591 ** Trace state variables
3593 GDB tracepoints now include support for trace state variables, which
3594 are variables managed by the target agent during a tracing
3595 experiment. They are useful for tracepoints that trigger each
3596 other, so for instance one tracepoint can count hits in a variable,
3597 and then a second tracepoint has a condition that is true when the
3598 count reaches a particular value. Trace state variables share the
3599 $-syntax of GDB convenience variables, and can appear in both
3600 tracepoint actions and condition expressions. Use the "tvariable"
3601 command to create, and "info tvariables" to view; see "Trace State
3602 Variables" in the manual for more detail.
3606 GDB now includes an option for defining fast tracepoints, which
3607 targets may implement more efficiently, such as by installing a jump
3608 into the target agent rather than a trap instruction. The resulting
3609 speedup can be by two orders of magnitude or more, although the
3610 tradeoff is that some program locations on some target architectures
3611 might not allow fast tracepoint installation, for instance if the
3612 instruction to be replaced is shorter than the jump. To request a
3613 fast tracepoint, use the "ftrace" command, with syntax identical to
3614 the regular trace command.
3616 ** Disconnected tracing
3618 It is now possible to detach GDB from the target while it is running
3619 a trace experiment, then reconnect later to see how the experiment
3620 is going. In addition, a new variable disconnected-tracing lets you
3621 tell the target agent whether to continue running a trace if the
3622 connection is lost unexpectedly.
3626 GDB now has the ability to save the trace buffer into a file, and
3627 then use that file as a target, similarly to you can do with
3628 corefiles. You can select trace frames, print data that was
3629 collected in them, and use tstatus to display the state of the
3630 tracing run at the moment that it was saved. To create a trace
3631 file, use "tsave <filename>", and to use it, do "target tfile
3634 ** Circular trace buffer
3636 You can ask the target agent to handle the trace buffer as a
3637 circular buffer, discarding the oldest trace frames to make room for
3638 newer ones, by setting circular-trace-buffer to on. This feature may
3639 not be available for all target agents.
3644 The disassemble command, when invoked with two arguments, now requires
3645 the arguments to be comma-separated.
3648 The info variables command now displays variable definitions. Files
3649 which only declare a variable are not shown.
3652 The source command is now capable of sourcing Python scripts.
3653 This feature is dependent on the debugger being build with Python
3656 Related to this enhancement is also the introduction of a new command
3657 "set script-extension" (see below).
3659 * New commands (for set/show, see "New options" below)
3661 record save [<FILENAME>]
3662 Save a file (in core file format) containing the process record
3663 execution log for replay debugging at a later time.
3665 record restore <FILENAME>
3666 Restore the process record execution log that was saved at an
3667 earlier time, for replay debugging.
3669 add-inferior [-copies <N>] [-exec <FILENAME>]
3672 clone-inferior [-copies <N>] [ID]
3673 Make a new inferior ready to execute the same program another
3674 inferior has loaded.
3679 maint info program-spaces
3680 List the program spaces loaded into GDB.
3682 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3683 show remote interrupt-sequence
3684 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3685 as the sequence to the remote target in order to interrupt the execution.
3686 Ctrl-C is a default. Some system prefers BREAK which is high level of
3687 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3688 Magic SysRq g. It is BREAK signal and character 'g'.
3690 set remote interrupt-on-connect [on | off]
3691 show remote interrupt-on-connect
3692 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3693 remote target when gdb connects to it. This is needed when you debug
3696 set remotebreak [on | off]
3698 Deprecated. Use "set/show remote interrupt-sequence" instead.
3700 tvariable $NAME [ = EXP ]
3701 Create or modify a trace state variable.
3704 List trace state variables and their values.
3706 delete tvariable $NAME ...
3707 Delete one or more trace state variables.
3710 Evaluate the given expressions without collecting anything into the
3711 trace buffer. (Valid in tracepoint actions only.)
3713 ftrace FN / FILE:LINE / *ADDR
3714 Define a fast tracepoint at the given function, line, or address.
3716 * New expression syntax
3718 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3719 GDB now parses 0b101010 identically with 42.
3723 set follow-exec-mode new|same
3724 show follow-exec-mode
3725 Control whether GDB reuses the same inferior across an exec call or
3726 creates a new one. This is useful to be able to restart the old
3727 executable after the inferior having done an exec call.
3729 set default-collect EXPR, ...
3730 show default-collect
3731 Define a list of expressions to be collected at each tracepoint.
3732 This is a useful way to ensure essential items are not overlooked,
3733 such as registers or a critical global variable.
3735 set disconnected-tracing
3736 show disconnected-tracing
3737 If set to 1, the target is instructed to continue tracing if it
3738 loses its connection to GDB. If 0, the target is to stop tracing
3741 set circular-trace-buffer
3742 show circular-trace-buffer
3743 If set to on, the target is instructed to use a circular trace buffer
3744 and discard the oldest trace frames instead of stopping the trace due
3745 to a full trace buffer. If set to off, the trace stops when the buffer
3746 fills up. Some targets may not support this.
3748 set script-extension off|soft|strict
3749 show script-extension
3750 If set to "off", the debugger does not perform any script language
3751 recognition, and all sourced files are assumed to be GDB scripts.
3752 If set to "soft" (the default), files are sourced according to
3753 filename extension, falling back to GDB scripts if the first
3755 If set to "strict", files are sourced according to filename extension.
3757 set ada trust-PAD-over-XVS on|off
3758 show ada trust-PAD-over-XVS
3759 If off, activate a workaround against a bug in the debugging information
3760 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3761 the GCC sources for more information about the GNAT encoding and
3762 PAD types in particular). It is always safe to set this option to
3763 off, but this introduces a slight performance penalty. The default
3766 * Python API Improvements
3768 ** GDB provides the new class gdb.LazyString. This is useful in
3769 some pretty-printing cases. The new method gdb.Value.lazy_string
3770 provides a simple way to create objects of this type.
3772 ** The fields returned by gdb.Type.fields now have an
3773 `is_base_class' attribute.
3775 ** The new method gdb.Type.range returns the range of an array type.
3777 ** The new method gdb.parse_and_eval can be used to parse and
3778 evaluate an expression.
3780 * New remote packets
3783 Define a trace state variable.
3786 Get the current value of a trace state variable.
3789 Set desired tracing behavior upon disconnection.
3792 Set the trace buffer to be linear or circular.
3795 Get data about the tracepoints currently in use.
3799 Process record now works correctly with hardware watchpoints.
3801 Multiple bug fixes have been made to the mips-irix port, making it
3802 much more reliable. In particular:
3803 - Debugging threaded applications is now possible again. Previously,
3804 GDB would hang while starting the program, or while waiting for
3805 the program to stop at a breakpoint.
3806 - Attaching to a running process no longer hangs.
3807 - An error occurring while loading a core file has been fixed.
3808 - Changing the value of the PC register now works again. This fixes
3809 problems observed when using the "jump" command, or when calling
3810 a function from GDB, or even when assigning a new value to $pc.
3811 - With the "finish" and "return" commands, the return value for functions
3812 returning a small array is now correctly printed.
3813 - It is now possible to break on shared library code which gets executed
3814 during a shared library init phase (code executed while executing
3815 their .init section). Previously, the breakpoint would have no effect.
3816 - GDB is now able to backtrace through the signal handler for
3817 non-threaded programs.
3819 PIE (Position Independent Executable) programs debugging is now supported.
3820 This includes debugging execution of PIC (Position Independent Code) shared
3821 libraries although for that, it should be possible to run such libraries as an
3824 *** Changes in GDB 7.0
3826 * GDB now has an interface for JIT compilation. Applications that
3827 dynamically generate code can create symbol files in memory and register
3828 them with GDB. For users, the feature should work transparently, and
3829 for JIT developers, the interface is documented in the GDB manual in the
3830 "JIT Compilation Interface" chapter.
3832 * Tracepoints may now be conditional. The syntax is as for
3833 breakpoints; either an "if" clause appended to the "trace" command,
3834 or the "condition" command is available. GDB sends the condition to
3835 the target for evaluation using the same bytecode format as is used
3836 for tracepoint actions.
3838 * The disassemble command now supports: an optional /r modifier, print the
3839 raw instructions in hex as well as in symbolic form, and an optional /m
3840 modifier to print mixed source+assembly.
3842 * Process record and replay
3844 In a architecture environment that supports ``process record and
3845 replay'', ``process record and replay'' target can record a log of
3846 the process execution, and replay it with both forward and reverse
3849 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3850 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3851 set execution-direction {forward|reverse}, for targets that support
3854 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3855 feature is available with a native GDB running on kernel version
3858 * GDB now has support for multi-byte and wide character sets on the
3859 target. Strings whose character type is wchar_t, char16_t, or
3860 char32_t are now correctly printed. GDB supports wide- and unicode-
3861 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3862 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3863 `printf'. This feature requires iconv to work properly; if your
3864 system does not have a working iconv, GDB can use GNU libiconv. See
3865 the installation instructions for more information.
3867 * GDB now supports automatic retrieval of shared library files from
3868 remote targets. To use this feature, specify a system root that begins
3869 with the `remote:' prefix, either via the `set sysroot' command or via
3870 the `--with-sysroot' configure-time option.
3872 * "info sharedlibrary" now takes an optional regex of libraries to show,
3873 and it now reports if a shared library has no debugging information.
3875 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3876 now complete on file names.
3878 * When completing in expressions, gdb will attempt to limit
3879 completions to allowable structure or union fields, where appropriate.
3880 For instance, consider:
3882 # struct example { int f1; double f2; };
3883 # struct example variable;
3886 If the user types TAB at the end of this command line, the available
3887 completions will be "f1" and "f2".
3889 * Inlined functions are now supported. They show up in backtraces, and
3890 the "step", "next", and "finish" commands handle them automatically.
3892 * GDB now supports the token-splicing (##) and stringification (#)
3893 operators when expanding macros. It also supports variable-arity
3896 * GDB now supports inspecting extra signal information, exported by
3897 the new $_siginfo convenience variable. The feature is currently
3898 implemented on linux ARM, i386 and amd64.
3900 * GDB can now display the VFP floating point registers and NEON vector
3901 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3902 can provide these registers (requires Linux 2.6.30 or later). Remote
3903 and simulator targets may also provide them.
3905 * New remote packets
3908 Search memory for a sequence of bytes.
3911 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3912 operation over reliable transport links. Use of this packet is
3913 controlled by the `set remote noack-packet' command.
3916 Kill the process with the specified process ID. Use this in preference
3917 to `k' when multiprocess protocol extensions are supported.
3920 Obtains additional operating system information
3924 Read or write additional signal information.
3926 * Removed remote protocol undocumented extension
3928 An undocumented extension to the remote protocol's `S' stop reply
3929 packet that permited the stub to pass a process id was removed.
3930 Remote servers should use the `T' stop reply packet instead.
3932 * GDB now supports multiple function calling conventions according to the
3933 DWARF-2 DW_AT_calling_convention function attribute.
3935 * The SH target utilizes the aforementioned change to distinguish between gcc
3936 and Renesas calling convention. It also adds the new CLI commands
3937 `set/show sh calling-convention'.
3939 * GDB can now read compressed debug sections, as produced by GNU gold
3940 with the --compress-debug-sections=zlib flag.
3942 * 64-bit core files are now supported on AIX.
3944 * Thread switching is now supported on Tru64.
3946 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3947 which will be allocated using malloc later in program execution.
3949 * The qXfer:libraries:read remote procotol packet now allows passing a
3950 list of section offsets.
3952 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3953 conditions handling signals delivered during attach or thread creation
3954 have also been fixed.
3956 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3957 From the user's standpoint, all unqualified instances of True and False
3958 are treated as the standard definitions, regardless of context.
3960 * GDB now parses C++ symbol and type names more flexibly. For
3963 template<typename T> class C { };
3966 GDB will now correctly handle all of:
3968 ptype C<char const *>
3969 ptype C<char const*>
3970 ptype C<const char *>
3971 ptype C<const char*>
3973 * New features in the GDB remote stub, gdbserver
3975 - The "--wrapper" command-line argument tells gdbserver to use a
3976 wrapper program to launch programs for debugging.
3978 - On PowerPC and S/390 targets, it is now possible to use a single
3979 gdbserver executable to debug both 32-bit and 64-bit programs.
3980 (This requires gdbserver itself to be built as a 64-bit executable.)
3982 - gdbserver uses the new noack protocol mode for TCP connections to
3983 reduce communications latency, if also supported and enabled in GDB.
3985 - Support for the sparc64-linux-gnu target is now included in
3988 - The amd64-linux build of gdbserver now supports debugging both
3989 32-bit and 64-bit programs.
3991 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3992 now support hardware watchpoints, and will use them automatically
3997 GDB now has support for scripting using Python. Whether this is
3998 available is determined at configure time.
4000 New GDB commands can now be written in Python.
4002 * Ada tasking support
4004 Ada tasks can now be inspected in GDB. The following commands have
4008 Print the list of Ada tasks.
4010 Print detailed information about task number N.
4012 Print the task number of the current task.
4014 Switch the context of debugging to task number N.
4016 * Support for user-defined prefixed commands. The "define" command can
4017 add new commands to existing prefixes, e.g. "target".
4019 * Multi-inferior, multi-process debugging.
4021 GDB now has generalized support for multi-inferior debugging. See
4022 "Debugging Multiple Inferiors" in the manual for more information.
4023 Although availability still depends on target support, the command
4024 set is more uniform now. The GNU/Linux specific multi-forks support
4025 has been migrated to this new framework. This implied some user
4026 visible changes; see "New commands" and also "Removed commands"
4029 * Target descriptions can now describe the target OS ABI. See the
4030 "Target Description Format" section in the user manual for more
4033 * Target descriptions can now describe "compatible" architectures
4034 to indicate that the target can execute applications for a different
4035 architecture in addition to those for the main target architecture.
4036 See the "Target Description Format" section in the user manual for
4039 * Multi-architecture debugging.
4041 GDB now includes general supports for debugging applications on
4042 hybrid systems that use more than one single processor architecture
4043 at the same time. Each such hybrid architecture still requires
4044 specific support to be added. The only hybrid architecture supported
4045 in this version of GDB is the Cell Broadband Engine.
4047 * GDB now supports integrated debugging of Cell/B.E. applications that
4048 use both the PPU and SPU architectures. To enable support for hybrid
4049 Cell/B.E. debugging, you need to configure GDB to support both the
4050 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4051 --enable-targets configure option.
4053 * Non-stop mode debugging.
4055 For some targets, GDB now supports an optional mode of operation in
4056 which you can examine stopped threads while other threads continue
4057 to execute freely. This is referred to as non-stop mode, with the
4058 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4059 section in the user manual for more information.
4061 To be able to support remote non-stop debugging, a remote stub needs
4062 to implement the non-stop mode remote protocol extensions, as
4063 described in the "Remote Non-Stop" section of the user manual. The
4064 GDB remote stub, gdbserver, has been adjusted to support these
4065 extensions on linux targets.
4067 * New commands (for set/show, see "New options" below)
4069 catch syscall [NAME(S) | NUMBER(S)]
4070 Catch system calls. Arguments, which should be names of system
4071 calls or their numbers, mean catch only those syscalls. Without
4072 arguments, every syscall will be caught. When the inferior issues
4073 any of the specified syscalls, GDB will stop and announce the system
4074 call, both when it is called and when its call returns. This
4075 feature is currently available with a native GDB running on the
4076 Linux Kernel, under the following architectures: x86, x86_64,
4077 PowerPC and PowerPC64.
4079 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4081 Search memory for a sequence of bytes.
4083 maint set python print-stack
4084 maint show python print-stack
4085 Show a stack trace when an error is encountered in a Python script.
4088 Invoke CODE by passing it to the Python interpreter.
4093 These allow macros to be defined, undefined, and listed
4097 Show operating system information about processes.
4100 List the inferiors currently under GDB's control.
4103 Switch focus to inferior number NUM.
4106 Detach from inferior number NUM.
4109 Kill inferior number NUM.
4113 set spu stop-on-load
4114 show spu stop-on-load
4115 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4117 set spu auto-flush-cache
4118 show spu auto-flush-cache
4119 Control whether to automatically flush the software-managed cache
4120 during Cell/B.E. debugging.
4122 set sh calling-convention
4123 show sh calling-convention
4124 Control the calling convention used when calling SH target functions.
4127 show debug timestamp
4128 Control display of timestamps with GDB debugging output.
4130 set disassemble-next-line
4131 show disassemble-next-line
4132 Control display of disassembled source lines or instructions when
4135 set remote noack-packet
4136 show remote noack-packet
4137 Set/show the use of remote protocol QStartNoAckMode packet. See above
4138 under "New remote packets."
4140 set remote query-attached-packet
4141 show remote query-attached-packet
4142 Control use of remote protocol `qAttached' (query-attached) packet.
4144 set remote read-siginfo-object
4145 show remote read-siginfo-object
4146 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4149 set remote write-siginfo-object
4150 show remote write-siginfo-object
4151 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4154 set remote reverse-continue
4155 show remote reverse-continue
4156 Control use of remote protocol 'bc' (reverse-continue) packet.
4158 set remote reverse-step
4159 show remote reverse-step
4160 Control use of remote protocol 'bs' (reverse-step) packet.
4162 set displaced-stepping
4163 show displaced-stepping
4164 Control displaced stepping mode. Displaced stepping is a way to
4165 single-step over breakpoints without removing them from the debuggee.
4166 Also known as "out-of-line single-stepping".
4169 show debug displaced
4170 Control display of debugging info for displaced stepping.
4172 maint set internal-error
4173 maint show internal-error
4174 Control what GDB does when an internal error is detected.
4176 maint set internal-warning
4177 maint show internal-warning
4178 Control what GDB does when an internal warning is detected.
4183 Use a wrapper program to launch programs for debugging.
4185 set multiple-symbols (all|ask|cancel)
4186 show multiple-symbols
4187 The value of this variable can be changed to adjust the debugger behavior
4188 when an expression or a breakpoint location contains an ambiguous symbol
4189 name (an overloaded function name, for instance).
4191 set breakpoint always-inserted
4192 show breakpoint always-inserted
4193 Keep breakpoints always inserted in the target, as opposed to inserting
4194 them when resuming the target, and removing them when the target stops.
4195 This option can improve debugger performance on slow remote targets.
4197 set arm fallback-mode (arm|thumb|auto)
4198 show arm fallback-mode
4199 set arm force-mode (arm|thumb|auto)
4201 These commands control how ARM GDB determines whether instructions
4202 are ARM or Thumb. The default for both settings is auto, which uses
4203 the current CPSR value for instructions without symbols; previous
4204 versions of GDB behaved as if "set arm fallback-mode arm".
4206 set disable-randomization
4207 show disable-randomization
4208 Standalone programs run with the virtual address space randomization enabled
4209 by default on some platforms. This option keeps the addresses stable across
4210 multiple debugging sessions.
4214 Control whether other threads are stopped or not when some thread hits
4219 Requests that asynchronous execution is enabled in the target, if available.
4220 In this case, it's possible to resume target in the background, and interact
4221 with GDB while the target is running. "show target-async" displays the
4222 current state of asynchronous execution of the target.
4224 set target-wide-charset
4225 show target-wide-charset
4226 The target-wide-charset is the name of the character set that GDB
4227 uses when printing characters whose type is wchar_t.
4229 set tcp auto-retry (on|off)
4231 set tcp connect-timeout
4232 show tcp connect-timeout
4233 These commands allow GDB to retry failed TCP connections to a remote stub
4234 with a specified timeout period; this is useful if the stub is launched
4235 in parallel with GDB but may not be ready to accept connections immediately.
4237 set libthread-db-search-path
4238 show libthread-db-search-path
4239 Control list of directories which GDB will search for appropriate
4242 set schedule-multiple (on|off)
4243 show schedule-multiple
4244 Allow GDB to resume all threads of all processes or only threads of
4245 the current process.
4249 Use more aggressive caching for accesses to the stack. This improves
4250 performance of remote debugging (particularly backtraces) without
4251 affecting correctness.
4253 set interactive-mode (on|off|auto)
4254 show interactive-mode
4255 Control whether GDB runs in interactive mode (on) or not (off).
4256 When in interactive mode, GDB waits for the user to answer all
4257 queries. Otherwise, GDB does not wait and assumes the default
4258 answer. When set to auto (the default), GDB determines which
4259 mode to use based on the stdin settings.
4264 For program forks, this is replaced by the new more generic `info
4265 inferiors' command. To list checkpoints, you can still use the
4266 `info checkpoints' command, which was an alias for the `info forks'
4270 Replaced by the new `inferior' command. To switch between
4271 checkpoints, you can still use the `restart' command, which was an
4272 alias for the `fork' command.
4275 This is removed, since some targets don't have a notion of
4276 processes. To switch between processes, you can still use the
4277 `inferior' command using GDB's own inferior number.
4280 For program forks, this is replaced by the new more generic `kill
4281 inferior' command. To delete a checkpoint, you can still use the
4282 `delete checkpoint' command, which was an alias for the `delete
4286 For program forks, this is replaced by the new more generic `detach
4287 inferior' command. To detach a checkpoint, you can still use the
4288 `detach checkpoint' command, which was an alias for the `detach
4291 * New native configurations
4293 x86/x86_64 Darwin i[34567]86-*-darwin*
4295 x86_64 MinGW x86_64-*-mingw*
4299 Lattice Mico32 lm32-*
4300 x86 DICOS i[34567]86-*-dicos*
4301 x86_64 DICOS x86_64-*-dicos*
4304 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4305 (mingw32ce) debugging.
4311 These commands were actually not implemented on any target.
4313 *** Changes in GDB 6.8
4315 * New native configurations
4317 NetBSD/hppa hppa*-*netbsd*
4318 Xtensa GNU/Linux xtensa*-*-linux*
4322 NetBSD/hppa hppa*-*-netbsd*
4323 Xtensa GNU/Lunux xtensa*-*-linux*
4325 * Change in command line behavior -- corefiles vs. process ids.
4327 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4328 attaching to process NUMBER fails, GDB no longer attempts to open a
4329 core file named NUMBER. Attaching to a program using the -c option
4330 is no longer supported. Instead, use the '-p' or '--pid' options.
4332 * GDB can now be built as a native debugger for debugging Windows x86
4333 (mingw32) Portable Executable (PE) programs.
4335 * Pending breakpoints no longer change their number when their address
4338 * GDB now supports breakpoints with multiple locations,
4339 including breakpoints on C++ constructors, inside C++ templates,
4340 and in inlined functions.
4342 * GDB's ability to debug optimized code has been improved. GDB more
4343 accurately identifies function bodies and lexical blocks that occupy
4344 more than one contiguous range of addresses.
4346 * Target descriptions can now describe registers for PowerPC.
4348 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4349 registers on PowerPC targets.
4351 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4352 targets even when the libthread_db library is not available.
4354 * The GDB remote stub, gdbserver, now supports the new file transfer
4355 commands (remote put, remote get, and remote delete).
4357 * The GDB remote stub, gdbserver, now supports run and attach in
4358 extended-remote mode.
4360 * hppa*64*-*-hpux11* target broken
4361 The debugger is unable to start a program and fails with the following
4362 error: "Error trying to get information about dynamic linker".
4363 The gdb-6.7 release is also affected.
4365 * GDB now supports the --enable-targets= configure option to allow
4366 building a single GDB executable that supports multiple remote
4367 target architectures.
4369 * GDB now supports debugging C and C++ programs which use the
4370 Decimal Floating Point extension. In addition, the PowerPC target
4371 now has a set of pseudo-registers to inspect decimal float values
4372 stored in two consecutive float registers.
4374 * The -break-insert MI command can optionally create pending
4377 * Improved support for debugging Ada
4378 Many improvements to the Ada language support have been made. These
4380 - Better support for Ada2005 interface types
4381 - Improved handling of arrays and slices in general
4382 - Better support for Taft-amendment types
4383 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4385 - Improved command completion in Ada
4388 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4393 set print frame-arguments (all|scalars|none)
4394 show print frame-arguments
4395 The value of this variable can be changed to control which argument
4396 values should be printed by the debugger when displaying a frame.
4401 Transfer files to and from a remote target, and delete remote files.
4408 Transfer files to and from a remote target, and delete remote files.
4410 * New remote packets
4417 Open, close, read, write, and delete files on the remote system.
4420 Attach to an existing process on the remote system, in extended-remote
4424 Run a new process on the remote system, in extended-remote mode.
4426 *** Changes in GDB 6.7
4428 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4429 bfd, libiberty and opcodes, as revealed by static analysis donated by
4430 Coverity, Inc. (http://scan.coverity.com).
4432 * When looking up multiply-defined global symbols, GDB will now prefer the
4433 symbol definition in the current shared library if it was built using the
4434 -Bsymbolic linker option.
4436 * When the Text User Interface (TUI) is not configured, GDB will now
4437 recognize the -tui command-line option and print a message that the TUI
4440 * The GDB remote stub, gdbserver, now has lower overhead for high
4441 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4443 * GDB for MIPS targets now autodetects whether a remote target provides
4444 32-bit or 64-bit register values.
4446 * Support for C++ member pointers has been improved.
4448 * GDB now understands XML target descriptions, which specify the
4449 target's overall architecture. GDB can read a description from
4450 a local file or over the remote serial protocol.
4452 * Vectors of single-byte data use a new integer type which is not
4453 automatically displayed as character or string data.
4455 * The /s format now works with the print command. It displays
4456 arrays of single-byte integers and pointers to single-byte integers
4459 * Target descriptions can now describe target-specific registers,
4460 for architectures which have implemented the support (currently
4461 only ARM, M68K, and MIPS).
4463 * GDB and the GDB remote stub, gdbserver, now support the XScale
4466 * The GDB remote stub, gdbserver, has been updated to support
4467 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4468 has been rewritten to use the standard GDB remote protocol.
4470 * GDB can now step into C++ functions which are called through thunks.
4472 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4474 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4475 layout. It also supports a TextSeg= and DataSeg= response when only
4476 segment base addresses (rather than offsets) are available.
4478 * The /i format now outputs any trailing branch delay slot instructions
4479 immediately following the last instruction within the count specified.
4481 * The GDB remote protocol "T" stop reply packet now supports a
4482 "library" response. Combined with the new "qXfer:libraries:read"
4483 packet, this response allows GDB to debug shared libraries on targets
4484 where the operating system manages the list of loaded libraries (e.g.
4485 Windows and SymbianOS).
4487 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4488 (DLLs) on Windows and Windows CE targets.
4490 * GDB now supports a faster verification that a .debug file matches its binary
4491 according to its build-id signature, if the signature is present.
4497 Enable or disable hardware flow control (RTS/CTS) on the serial port
4498 when debugging using remote targets.
4500 set mem inaccessible-by-default
4501 show mem inaccessible-by-default
4502 If the target supplies a memory map, for instance via the remote
4503 protocol's "qXfer:memory-map:read" packet, setting this variable
4504 prevents GDB from accessing memory outside the memory map. This
4505 is useful for targets with memory mapped registers or which react
4506 badly to accesses of unmapped address space.
4508 set breakpoint auto-hw
4509 show breakpoint auto-hw
4510 If the target supplies a memory map, for instance via the remote
4511 protocol's "qXfer:memory-map:read" packet, setting this variable
4512 lets GDB use hardware breakpoints automatically for memory regions
4513 where it can not use software breakpoints. This covers both the
4514 "break" command and internal breakpoints used for other commands
4515 including "next" and "finish".
4518 catch exception unhandled
4519 Stop the program execution when Ada exceptions are raised.
4522 Stop the program execution when an Ada assertion failed.
4526 Set an alternate system root for target files. This is a more
4527 general version of "set solib-absolute-prefix", which is now
4528 an alias to "set sysroot".
4531 Provide extended SPU facility status information. This set of
4532 commands is available only when debugging the Cell/B.E. SPU
4535 * New native configurations
4537 OpenBSD/sh sh*-*openbsd*
4540 unset tdesc filename
4542 Use the specified local file as an XML target description, and do
4543 not query the target for its built-in description.
4547 OpenBSD/sh sh*-*-openbsd*
4548 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4549 Toshiba Media Processor mep-elf
4551 * New remote packets
4554 Ignore the specified signals; pass them directly to the debugged program
4555 without stopping other threads or reporting them to GDB.
4557 qXfer:features:read:
4558 Read an XML target description from the target, which describes its
4563 Read or write contents of an spufs file on the target system. These
4564 packets are available only on the Cell/B.E. SPU architecture.
4566 qXfer:libraries:read:
4567 Report the loaded shared libraries. Combined with new "T" packet
4568 response, this packet allows GDB to debug shared libraries on
4569 targets where the operating system manages the list of loaded
4570 libraries (e.g. Windows and SymbianOS).
4574 Support for these obsolete configurations has been removed.
4582 i[34567]86-*-lynxos*
4583 i[34567]86-*-netware*
4584 i[34567]86-*-sco3.2v5*
4585 i[34567]86-*-sco3.2v4*
4587 i[34567]86-*-sysv4.2*
4590 i[34567]86-*-unixware2*
4591 i[34567]86-*-unixware*
4600 * Other removed features
4607 Various m68k-only ROM monitors.
4614 Various Renesas ROM monitors and debugging interfaces for SH and
4619 Support for a Macraigor serial interface to on-chip debugging.
4620 GDB does not directly support the newer parallel or USB
4625 A debug information format. The predecessor to DWARF 2 and
4626 DWARF 3, which are still supported.
4628 Support for the HP aCC compiler on HP-UX/PA-RISC
4630 SOM-encapsulated symbolic debugging information, automatic
4631 invocation of pxdb, and the aCC custom C++ ABI. This does not
4632 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4633 with aCC can still be debugged on an assembly level.
4635 MIPS ".pdr" sections
4637 A MIPS-specific format used to describe stack frame layout
4638 in debugging information.
4642 GDB could work with an older version of Guile to debug
4643 the interpreter and Scheme programs running in it.
4645 set mips stack-arg-size
4646 set mips saved-gpreg-size
4648 Use "set mips abi" to control parameter passing for MIPS.
4650 *** Changes in GDB 6.6
4655 Cell Broadband Engine SPU spu-elf
4657 * GDB can now be configured as a cross-debugger targeting native Windows
4658 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4659 running on a Windows system over TCP/IP to debug Windows programs.
4661 * The GDB remote stub, gdbserver, has been updated to support Windows and
4662 Cygwin debugging. Both single-threaded and multi-threaded programs are
4665 * The "set trust-readonly-sections" command works again. This command was
4666 broken in GDB 6.3, 6.4, and 6.5.
4668 * The "load" command now supports writing to flash memory, if the remote
4669 stub provides the required support.
4671 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4672 longer requires symbolic debug information (e.g. DWARF-2).
4677 unset substitute-path
4678 show substitute-path
4679 Manage a list of substitution rules that GDB uses to rewrite the name
4680 of the directories where the sources are located. This can be useful
4681 for instance when the sources were moved to a different location
4682 between compilation and debugging.
4686 Print each CLI command as it is executed. Each command is prefixed with
4687 a number of `+' symbols representing the nesting depth.
4688 The source command now has a `-v' option to enable the same feature.
4692 The ARM Demon monitor support (RDP protocol, "target rdp").
4694 Kernel Object Display, an embedded debugging feature which only worked with
4695 an obsolete version of Cisco IOS.
4697 The 'set download-write-size' and 'show download-write-size' commands.
4699 * New remote packets
4702 Tell a stub about GDB client features, and request remote target features.
4703 The first feature implemented is PacketSize, which allows the target to
4704 specify the size of packets it can handle - to minimize the number of
4705 packets required and improve performance when connected to a remote
4709 Fetch an OS auxilliary vector from the remote stub. This packet is a
4710 more efficient replacement for qPart:auxv:read.
4712 qXfer:memory-map:read:
4713 Fetch a memory map from the remote stub, including information about
4714 RAM, ROM, and flash memory devices.
4719 Erase and program a flash memory device.
4721 * Removed remote packets
4724 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4725 used it, and only gdbserver implemented it.
4727 *** Changes in GDB 6.5
4731 Renesas M32C/M16C m32c-elf
4733 Morpho Technologies ms1 ms1-elf
4737 init-if-undefined Initialize a convenience variable, but
4738 only if it doesn't already have a value.
4740 The following commands are presently only implemented for native GNU/Linux:
4742 checkpoint Save a snapshot of the program state.
4744 restart <n> Return the program state to a
4745 previously saved state.
4747 info checkpoints List currently saved checkpoints.
4749 delete-checkpoint <n> Delete a previously saved checkpoint.
4751 set|show detach-on-fork Tell gdb whether to detach from a newly
4752 forked process, or to keep debugging it.
4754 info forks List forks of the user program that
4755 are available to be debugged.
4757 fork <n> Switch to debugging one of several
4758 forks of the user program that are
4759 available to be debugged.
4761 delete-fork <n> Delete a fork from the list of forks
4762 that are available to be debugged (and
4763 kill the forked process).
4765 detach-fork <n> Delete a fork from the list of forks
4766 that are available to be debugged (and
4767 allow the process to continue).
4771 Morpho Technologies ms2 ms1-elf
4773 * Improved Windows host support
4775 GDB now builds as a cross debugger hosted on i686-mingw32, including
4776 native console support, and remote communications using either
4777 network sockets or serial ports.
4779 * Improved Modula-2 language support
4781 GDB can now print most types in the Modula-2 syntax. This includes:
4782 basic types, set types, record types, enumerated types, range types,
4783 pointer types and ARRAY types. Procedure var parameters are correctly
4784 printed and hexadecimal addresses and character constants are also
4785 written in the Modula-2 syntax. Best results can be obtained by using
4786 GNU Modula-2 together with the -gdwarf-2 command line option.
4790 The ARM rdi-share module.
4792 The Netware NLM debug server.
4794 *** Changes in GDB 6.4
4796 * New native configurations
4798 OpenBSD/arm arm*-*-openbsd*
4799 OpenBSD/mips64 mips64-*-openbsd*
4803 Morpho Technologies ms1 ms1-elf
4805 * New command line options
4807 --batch-silent As for --batch, but totally silent.
4808 --return-child-result The debugger will exist with the same value
4809 the child (debugged) program exited with.
4810 --eval-command COMMAND, -ex COMMAND
4811 Execute a single GDB CLI command. This may be
4812 specified multiple times and in conjunction
4813 with the --command (-x) option.
4815 * Deprecated commands removed
4817 The following commands, that were deprecated in 2000, have been
4821 set|show arm disassembly-flavor set|show arm disassembler
4822 othernames set arm disassembler
4823 set|show remotedebug set|show debug remote
4824 set|show archdebug set|show debug arch
4825 set|show eventdebug set|show debug event
4828 * New BSD user-level threads support
4830 It is now possible to debug programs using the user-level threads
4831 library on OpenBSD and FreeBSD. Currently supported (target)
4834 FreeBSD/amd64 x86_64-*-freebsd*
4835 FreeBSD/i386 i386-*-freebsd*
4836 OpenBSD/i386 i386-*-openbsd*
4838 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4839 are not yet supported.
4841 * New support for Matsushita MN10300 w/sim added
4842 (Work in progress). mn10300-elf.
4844 * REMOVED configurations and files
4846 VxWorks and the XDR protocol *-*-vxworks
4847 Motorola MCORE mcore-*-*
4848 National Semiconductor NS32000 ns32k-*-*
4850 * New "set print array-indexes" command
4852 After turning this setting "on", GDB prints the index of each element
4853 when displaying arrays. The default is "off" to preserve the previous
4856 * VAX floating point support
4858 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4860 * User-defined command support
4862 In addition to using $arg0..$arg9 for argument passing, it is now possible
4863 to use $argc to determine now many arguments have been passed. See the
4864 section on user-defined commands in the user manual for more information.
4866 *** Changes in GDB 6.3:
4868 * New command line option
4870 GDB now accepts -l followed by a number to set the timeout for remote
4873 * GDB works with GCC -feliminate-dwarf2-dups
4875 GDB now supports a more compact representation of DWARF-2 debug
4876 information using DW_FORM_ref_addr references. These are produced
4877 by GCC with the option -feliminate-dwarf2-dups and also by some
4878 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4879 to use -feliminate-dwarf2-dups.
4881 * Internationalization
4883 When supported by the host system, GDB will be built with
4884 internationalization (libintl). The task of marking up the sources is
4885 continued, we're looking forward to our first translation.
4889 Initial support for debugging programs compiled with the GNAT
4890 implementation of the Ada programming language has been integrated
4891 into GDB. In this release, support is limited to expression evaluation.
4893 * New native configurations
4895 GNU/Linux/m32r m32r-*-linux-gnu
4899 GDB's remote protocol now includes support for the 'p' packet. This
4900 packet is used to fetch individual registers from a remote inferior.
4902 * END-OF-LIFE registers[] compatibility module
4904 GDB's internal register infrastructure has been completely rewritten.
4905 The new infrastructure making possible the implementation of key new
4906 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4909 GDB 6.3 will be the last release to include the the registers[]
4910 compatibility module that allowed out-of-date configurations to
4911 continue to work. This change directly impacts the following
4921 powerpc bdm protocol
4923 Unless there is activity to revive these configurations, they will be
4924 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4926 * OBSOLETE configurations and files
4928 Configurations that have been declared obsolete in this release have
4929 been commented out. Unless there is activity to revive these
4930 configurations, the next release of GDB will have their sources
4931 permanently REMOVED.
4940 *** Changes in GDB 6.2.1:
4942 * MIPS `break main; run' gave an heuristic-fence-post warning
4944 When attempting to run even a simple program, a warning about
4945 heuristic-fence-post being hit would be reported. This problem has
4948 * MIPS IRIX 'long double' crashed GDB
4950 When examining a long double variable, GDB would get a segmentation
4951 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4952 IRIX long double values).
4956 A bug in the VAX stack code was causing problems with the "next"
4957 command. This problem has been fixed.
4959 *** Changes in GDB 6.2:
4961 * Fix for ``many threads''
4963 On GNU/Linux systems that use the NPTL threads library, a program
4964 rapidly creating and deleting threads would confuse GDB leading to the
4967 ptrace: No such process.
4968 thread_db_get_info: cannot get thread info: generic error
4970 This problem has been fixed.
4972 * "-async" and "-noasync" options removed.
4974 Support for the broken "-noasync" option has been removed (it caused
4977 * New ``start'' command.
4979 This command runs the program until the begining of the main procedure.
4981 * New BSD Kernel Data Access Library (libkvm) interface
4983 Using ``target kvm'' it is now possible to debug kernel core dumps and
4984 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4985 platforms. Currently supported (native-only) configurations are:
4987 FreeBSD/amd64 x86_64-*-freebsd*
4988 FreeBSD/i386 i?86-*-freebsd*
4989 NetBSD/i386 i?86-*-netbsd*
4990 NetBSD/m68k m68*-*-netbsd*
4991 NetBSD/sparc sparc-*-netbsd*
4992 OpenBSD/amd64 x86_64-*-openbsd*
4993 OpenBSD/i386 i?86-*-openbsd*
4994 OpenBSD/m68k m68*-openbsd*
4995 OpenBSD/sparc sparc-*-openbsd*
4997 * Signal trampoline code overhauled
4999 Many generic problems with GDB's signal handling code have been fixed.
5000 These include: backtraces through non-contiguous stacks; recognition
5001 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5002 call; backtrace through a signal trampoline; step into and out of
5003 signal handlers; and single-stepping in the signal trampoline.
5005 Please note that kernel bugs are a limiting factor here. These
5006 features have been shown to work on an s390 GNU/Linux system that
5007 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5009 * Cygwin support for DWARF 2 added.
5011 * New native configurations
5013 GNU/Linux/hppa hppa*-*-linux*
5014 OpenBSD/hppa hppa*-*-openbsd*
5015 OpenBSD/m68k m68*-*-openbsd*
5016 OpenBSD/m88k m88*-*-openbsd*
5017 OpenBSD/powerpc powerpc-*-openbsd*
5018 NetBSD/vax vax-*-netbsd*
5019 OpenBSD/vax vax-*-openbsd*
5021 * END-OF-LIFE frame compatibility module
5023 GDB's internal frame infrastructure has been completely rewritten.
5024 The new infrastructure making it possible to support key new features
5025 including DWARF 2 Call Frame Information. To aid in the task of
5026 migrating old configurations to this new infrastructure, a
5027 compatibility module, that allowed old configurations to continue to
5028 work, was also included.
5030 GDB 6.2 will be the last release to include this frame compatibility
5031 module. This change directly impacts the following configurations:
5041 Unless there is activity to revive these configurations, they will be
5042 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5044 * REMOVED configurations and files
5046 Sun 3, running SunOS 3 m68*-*-sunos3*
5047 Sun 3, running SunOS 4 m68*-*-sunos4*
5048 Sun 2, running SunOS 3 m68000-*-sunos3*
5049 Sun 2, running SunOS 4 m68000-*-sunos4*
5050 Motorola 680x0 running LynxOS m68*-*-lynxos*
5051 AT&T 3b1/Unix pc m68*-att-*
5052 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5053 decstation mips-dec-* mips-little-*
5054 riscos mips-*-riscos* mips-*-sysv*
5055 sonymips mips-sony-*
5056 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5058 *** Changes in GDB 6.1.1:
5060 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5062 The TUI (Text-mode User Interface) is now built as part of a default
5063 GDB configuration. It is enabled by either selecting the TUI with the
5064 command line option "-i=tui" or by running the separate "gdbtui"
5065 program. For more information on the TUI, see the manual "Debugging
5068 * Pending breakpoint support (also included in GDB 6.1)
5070 Support has been added to allow you to specify breakpoints in shared
5071 libraries that have not yet been loaded. If a breakpoint location
5072 cannot be found, and the "breakpoint pending" option is set to auto,
5073 GDB queries you if you wish to make the breakpoint pending on a future
5074 shared-library load. If and when GDB resolves the breakpoint symbol,
5075 the pending breakpoint is removed as one or more regular breakpoints
5078 Pending breakpoints are very useful for GCJ Java debugging.
5080 * Fixed ISO-C build problems
5082 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5083 non ISO-C code that stopped them being built using a more strict ISO-C
5084 compiler (e.g., IBM's C compiler).
5086 * Fixed build problem on IRIX 5
5088 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5089 wasn't able to compile compile on an IRIX 5 system.
5091 * Added execute permission to gdb/gdbserver/configure
5093 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5094 permission. This bug would cause configure to fail on a number of
5095 systems (Solaris, IRIX). Ref: server/519.
5097 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5099 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5100 has been updated to use constant array sizes.
5102 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5104 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5105 its generated DWARF Call Frame Info. This encoding was causing GDB to
5106 panic, that panic has been fixed. Ref: gdb/1628.
5108 * Fixed a problem when examining parameters in shared library code.
5110 When examining parameters in optimized shared library code generated
5111 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5112 not available''. GDB now correctly displays the variable's value.
5114 *** Changes in GDB 6.1:
5116 * Removed --with-mmalloc
5118 Support for the mmalloc memory manager has been removed, as it
5119 conflicted with the internal gdb byte cache.
5121 * Changes in AMD64 configurations
5123 The AMD64 target now includes the %cs and %ss registers. As a result
5124 the AMD64 remote protocol has changed; this affects the floating-point
5125 and SSE registers. If you rely on those registers for your debugging,
5126 you should upgrade gdbserver on the remote side.
5128 * Revised SPARC target
5130 The SPARC target has been completely revised, incorporating the
5131 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5132 support for LynxOS and SunOS 4 has been dropped. Calling functions
5133 from within GDB on operating systems with a non-executable stack
5134 (Solaris, OpenBSD) now works.
5138 GDB has a new C++ demangler which does a better job on the mangled
5139 names generated by current versions of g++. It also runs faster, so
5140 with this and other changes gdb should now start faster on large C++
5143 * DWARF 2 Location Expressions
5145 GDB support for location expressions has been extended to support function
5146 arguments and frame bases. Older versions of GDB could crash when they
5149 * C++ nested types and namespaces
5151 GDB's support for nested types and namespaces in C++ has been
5152 improved, especially if you use the DWARF 2 debugging format. (This
5153 is the default for recent versions of GCC on most platforms.)
5154 Specifically, if you have a class "Inner" defined within a class or
5155 namespace "Outer", then GDB realizes that the class's name is
5156 "Outer::Inner", not simply "Inner". This should greatly reduce the
5157 frequency of complaints about not finding RTTI symbols. In addition,
5158 if you are stopped at inside of a function defined within a namespace,
5159 GDB modifies its name lookup accordingly.
5161 * New native configurations
5163 NetBSD/amd64 x86_64-*-netbsd*
5164 OpenBSD/amd64 x86_64-*-openbsd*
5165 OpenBSD/alpha alpha*-*-openbsd*
5166 OpenBSD/sparc sparc-*-openbsd*
5167 OpenBSD/sparc64 sparc64-*-openbsd*
5169 * New debugging protocols
5171 M32R with SDI protocol m32r-*-elf*
5173 * "set prompt-escape-char" command deleted.
5175 The command "set prompt-escape-char" has been deleted. This command,
5176 and its very obscure effet on GDB's prompt, was never documented,
5177 tested, nor mentioned in the NEWS file.
5179 * OBSOLETE configurations and files
5181 Configurations that have been declared obsolete in this release have
5182 been commented out. Unless there is activity to revive these
5183 configurations, the next release of GDB will have their sources
5184 permanently REMOVED.
5186 Sun 3, running SunOS 3 m68*-*-sunos3*
5187 Sun 3, running SunOS 4 m68*-*-sunos4*
5188 Sun 2, running SunOS 3 m68000-*-sunos3*
5189 Sun 2, running SunOS 4 m68000-*-sunos4*
5190 Motorola 680x0 running LynxOS m68*-*-lynxos*
5191 AT&T 3b1/Unix pc m68*-att-*
5192 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5193 decstation mips-dec-* mips-little-*
5194 riscos mips-*-riscos* mips-*-sysv*
5195 sonymips mips-sony-*
5196 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5198 * REMOVED configurations and files
5200 SGI Irix-4.x mips-sgi-irix4 or iris4
5201 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5202 Z8000 simulator z8k-zilog-none or z8ksim
5203 Matsushita MN10200 w/simulator mn10200-*-*
5204 H8/500 simulator h8500-hitachi-hms or h8500hms
5205 HP/PA running BSD hppa*-*-bsd*
5206 HP/PA running OSF/1 hppa*-*-osf*
5207 HP/PA Pro target hppa*-*-pro*
5208 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5209 386BSD i[3456]86-*-bsd*
5210 Sequent family i[3456]86-sequent-sysv4*
5211 i[3456]86-sequent-sysv*
5212 i[3456]86-sequent-bsd*
5213 SPARC running LynxOS sparc-*-lynxos*
5214 SPARC running SunOS 4 sparc-*-sunos4*
5215 Tsqware Sparclet sparclet-*-*
5216 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5218 *** Changes in GDB 6.0:
5222 Support for debugging the Objective-C programming language has been
5223 integrated into GDB.
5225 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5227 DWARF 2's Call Frame Information makes available compiler generated
5228 information that more exactly describes the program's run-time stack.
5229 By using this information, GDB is able to provide more robust stack
5232 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5233 have been updated to use a new backtrace mechanism which includes
5234 DWARF 2 CFI support.
5238 GDB's remote protocol has been extended to include support for hosted
5239 file I/O (where the remote target uses GDB's file system). See GDB's
5240 remote protocol documentation for details.
5242 * All targets using the new architecture framework.
5244 All of GDB's targets have been updated to use the new internal
5245 architecture framework. The way is now open for future GDB releases
5246 to include cross-architecture native debugging support (i386 on amd64,
5249 * GNU/Linux's Thread Local Storage (TLS)
5251 GDB now includes support for for the GNU/Linux implementation of
5252 per-thread variables.
5254 * GNU/Linux's Native POSIX Thread Library (NPTL)
5256 GDB's thread code has been updated to work with either the new
5257 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5259 * Separate debug info.
5261 GDB, in conjunction with BINUTILS, now supports a mechanism for
5262 automatically loading debug information from a separate file. Instead
5263 of shipping full debug and non-debug versions of system libraries,
5264 system integrators can now instead ship just the stripped libraries
5265 and optional debug files.
5267 * DWARF 2 Location Expressions
5269 DWARF 2 Location Expressions allow the compiler to more completely
5270 describe the location of variables (even in optimized code) to the
5273 GDB now includes preliminary support for location expressions (support
5274 for DW_OP_piece is still missing).
5278 A number of long standing bugs that caused GDB to die while starting a
5279 Java application have been fixed. GDB's Java support is now
5280 considered "useable".
5282 * GNU/Linux support for fork, vfork, and exec.
5284 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5285 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5288 * GDB supports logging output to a file
5290 There are two new commands, "set logging" and "show logging", which can be
5291 used to capture GDB's output to a file.
5293 * The meaning of "detach" has changed for gdbserver
5295 The "detach" command will now resume the application, as documented. To
5296 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5299 * d10v, m68hc11 `regs' command deprecated
5301 The `info registers' command has been updated so that it displays the
5302 registers using a format identical to the old `regs' command.
5306 A new command, "maint set profile on/off", has been added. This command can
5307 be used to enable or disable profiling while running GDB, to profile a
5308 session or a set of commands. In addition there is a new configure switch,
5309 "--enable-profiling", which will cause GDB to be compiled with profiling
5310 data, for more informative profiling results.
5312 * Default MI syntax changed to "mi2".
5314 The default MI (machine interface) syntax, enabled by the command line
5315 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5316 "mi1", can be enabled by specifying the option "-i=mi1".
5318 Support for the original "mi0" syntax (included in GDB 5.0) has been
5321 Fix for gdb/192: removed extraneous space when displaying frame level.
5322 Fix for gdb/672: update changelist is now output in mi list format.
5323 Fix for gdb/702: a -var-assign that updates the value now shows up
5324 in a subsequent -var-update.
5326 * New native configurations.
5328 FreeBSD/amd64 x86_64-*-freebsd*
5330 * Multi-arched targets.
5332 HP/PA HPUX11 hppa*-*-hpux*
5333 Renesas M32R/D w/simulator m32r-*-elf*
5335 * OBSOLETE configurations and files
5337 Configurations that have been declared obsolete in this release have
5338 been commented out. Unless there is activity to revive these
5339 configurations, the next release of GDB will have their sources
5340 permanently REMOVED.
5342 Z8000 simulator z8k-zilog-none or z8ksim
5343 Matsushita MN10200 w/simulator mn10200-*-*
5344 H8/500 simulator h8500-hitachi-hms or h8500hms
5345 HP/PA running BSD hppa*-*-bsd*
5346 HP/PA running OSF/1 hppa*-*-osf*
5347 HP/PA Pro target hppa*-*-pro*
5348 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5349 Sequent family i[3456]86-sequent-sysv4*
5350 i[3456]86-sequent-sysv*
5351 i[3456]86-sequent-bsd*
5352 Tsqware Sparclet sparclet-*-*
5353 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5355 * REMOVED configurations and files
5358 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5359 IBM AIX PS/2 i[3456]86-*-aix
5360 i386 running Mach 3.0 i[3456]86-*-mach3*
5361 i386 running Mach i[3456]86-*-mach*
5362 i386 running OSF/1 i[3456]86-*osf1mk*
5363 HP/Apollo 68k Family m68*-apollo*-sysv*,
5365 m68*-hp-bsd*, m68*-hp-hpux*
5366 Argonaut Risc Chip (ARC) arc-*-*
5367 Mitsubishi D30V d30v-*-*
5368 Fujitsu FR30 fr30-*-elf*
5369 OS/9000 i[34]86-*-os9k
5370 I960 with MON960 i960-*-coff
5372 * MIPS $fp behavior changed
5374 The convenience variable $fp, for the MIPS, now consistently returns
5375 the address of the current frame's base. Previously, depending on the
5376 context, $fp could refer to either $sp or the current frame's base
5377 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5378 The GNU Source-Level Debugger''.
5380 *** Changes in GDB 5.3:
5382 * GNU/Linux shared library multi-threaded performance improved.
5384 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5385 `/proc', in preference to `ptrace' for memory reads. This may result
5386 in an improvement in the start-up time of multi-threaded, shared
5387 library applications when run under GDB. One GDB user writes: ``loads
5388 shared libs like mad''.
5390 * ``gdbserver'' now supports multi-threaded applications on some targets
5392 Support for debugging multi-threaded applications which use
5393 the GNU/Linux LinuxThreads package has been added for
5394 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5395 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5397 * GDB now supports C/C++ preprocessor macros.
5399 GDB now expands preprocessor macro invocations in C/C++ expressions,
5400 and provides various commands for showing macro definitions and how
5403 The new command `macro expand EXPRESSION' expands any macro
5404 invocations in expression, and shows the result.
5406 The new command `show macro MACRO-NAME' shows the definition of the
5407 macro named MACRO-NAME, and where it was defined.
5409 Most compilers don't include information about macros in the debugging
5410 information by default. In GCC 3.1, for example, you need to compile
5411 your program with the options `-gdwarf-2 -g3'. If the macro
5412 information is present in the executable, GDB will read it.
5414 * Multi-arched targets.
5416 DEC Alpha (partial) alpha*-*-*
5417 DEC VAX (partial) vax-*-*
5419 National Semiconductor NS32000 (partial) ns32k-*-*
5420 Motorola 68000 (partial) m68k-*-*
5421 Motorola MCORE mcore-*-*
5425 Fujitsu FRV architecture added by Red Hat frv*-*-*
5428 * New native configurations
5430 Alpha NetBSD alpha*-*-netbsd*
5431 SH NetBSD sh*-*-netbsdelf*
5432 MIPS NetBSD mips*-*-netbsd*
5433 UltraSPARC NetBSD sparc64-*-netbsd*
5435 * OBSOLETE configurations and files
5437 Configurations that have been declared obsolete in this release have
5438 been commented out. Unless there is activity to revive these
5439 configurations, the next release of GDB will have their sources
5440 permanently REMOVED.
5442 Mitsubishi D30V d30v-*-*
5443 OS/9000 i[34]86-*-os9k
5444 IBM AIX PS/2 i[3456]86-*-aix
5445 Fujitsu FR30 fr30-*-elf*
5446 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5447 Argonaut Risc Chip (ARC) arc-*-*
5448 i386 running Mach 3.0 i[3456]86-*-mach3*
5449 i386 running Mach i[3456]86-*-mach*
5450 i386 running OSF/1 i[3456]86-*osf1mk*
5451 HP/Apollo 68k Family m68*-apollo*-sysv*,
5453 m68*-hp-bsd*, m68*-hp-hpux*
5454 I960 with MON960 i960-*-coff
5456 * OBSOLETE languages
5458 CHILL, a Pascal like language used by telecommunications companies.
5460 * REMOVED configurations and files
5462 AMD 29k family via UDI a29k-amd-udi, udi29k
5463 A29K VxWorks a29k-*-vxworks
5464 AMD 29000 embedded, using EBMON a29k-none-none
5465 AMD 29000 embedded with COFF a29k-none-coff
5466 AMD 29000 embedded with a.out a29k-none-aout
5468 testsuite/gdb.hp/gdb.threads-hp/ directory
5470 * New command "set max-user-call-depth <nnn>"
5472 This command allows the user to limit the call depth of user-defined
5473 commands. The default is 1024.
5475 * Changes in FreeBSD/i386 native debugging.
5477 Support for the "generate-core-file" has been added.
5479 * New commands "dump", "append", and "restore".
5481 These commands allow data to be copied from target memory
5482 to a bfd-format or binary file (dump and append), and back
5483 from a file into memory (restore).
5485 * Improved "next/step" support on multi-processor Alpha Tru64.
5487 The previous single-step mechanism could cause unpredictable problems,
5488 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5489 of a software single-step mechanism prevents this.
5491 *** Changes in GDB 5.2.1:
5499 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5500 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5501 Fix, by Joel Brobecker imported from mainline.
5503 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5504 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5505 Fix, by Fred Fish, imported from mainline.
5507 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5508 Surprisingly enough, it works now.
5509 By Michal Ludvig, imported from mainline.
5511 i386 hardware watchpoint support:
5512 avoid misses on second run for some targets.
5513 By Pierre Muller, imported from mainline.
5515 *** Changes in GDB 5.2:
5517 * New command "set trust-readonly-sections on[off]".
5519 This command is a hint that tells gdb that read-only sections
5520 really are read-only (ie. that their contents will not change).
5521 In this mode, gdb will go to the object file rather than the
5522 target to read memory from read-only sections (such as ".text").
5523 This can be a significant performance improvement on some
5524 (notably embedded) targets.
5526 * New command "generate-core-file" (or "gcore").
5528 This new gdb command allows the user to drop a core file of the child
5529 process state at any time. So far it's been implemented only for
5530 GNU/Linux and Solaris, but should be relatively easily ported to other
5531 hosts. Argument is core file name (defaults to core.<pid>).
5533 * New command line option
5535 GDB now accepts --pid or -p followed by a process id.
5537 * Change in command line behavior -- corefiles vs. process ids.
5539 There is a subtle behavior in the way in which GDB handles
5540 command line arguments. The first non-flag argument is always
5541 a program to debug, but the second non-flag argument may either
5542 be a corefile or a process id. Previously, GDB would attempt to
5543 open the second argument as a corefile, and if that failed, would
5544 issue a superfluous error message and then attempt to attach it as
5545 a process. Now, if the second argument begins with a non-digit,
5546 it will be treated as a corefile. If it begins with a digit,
5547 GDB will attempt to attach it as a process, and if no such process
5548 is found, will then attempt to open it as a corefile.
5550 * Changes in ARM configurations.
5552 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5553 configuration is fully multi-arch.
5555 * New native configurations
5557 ARM NetBSD arm*-*-netbsd*
5558 x86 OpenBSD i[3456]86-*-openbsd*
5559 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5560 Sparc64 running FreeBSD sparc64-*-freebsd*
5564 Sanyo XStormy16 xstormy16-elf
5566 * OBSOLETE configurations and files
5568 Configurations that have been declared obsolete in this release have
5569 been commented out. Unless there is activity to revive these
5570 configurations, the next release of GDB will have their sources
5571 permanently REMOVED.
5573 AMD 29k family via UDI a29k-amd-udi, udi29k
5574 A29K VxWorks a29k-*-vxworks
5575 AMD 29000 embedded, using EBMON a29k-none-none
5576 AMD 29000 embedded with COFF a29k-none-coff
5577 AMD 29000 embedded with a.out a29k-none-aout
5579 testsuite/gdb.hp/gdb.threads-hp/ directory
5581 * REMOVED configurations and files
5583 TI TMS320C80 tic80-*-*
5585 PowerPC Solaris powerpcle-*-solaris*
5586 PowerPC Windows NT powerpcle-*-cygwin32
5587 PowerPC Netware powerpc-*-netware*
5588 Harris/CXUX m88k m88*-harris-cxux*
5589 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5590 ns32k-utek-sysv* ns32k-utek-*
5591 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5592 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5593 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5594 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5595 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5597 * Changes to command line processing
5599 The new `--args' feature can be used to specify command-line arguments
5600 for the inferior from gdb's command line.
5602 * Changes to key bindings
5604 There is a new `operate-and-get-next' function bound to `C-o'.
5606 *** Changes in GDB 5.1.1
5608 Fix compile problem on DJGPP.
5610 Fix a problem with floating-point registers on the i386 being
5613 Fix to stop GDB crashing on .debug_str debug info.
5615 Numerous documentation fixes.
5617 Numerous testsuite fixes.
5619 *** Changes in GDB 5.1:
5621 * New native configurations
5623 Alpha FreeBSD alpha*-*-freebsd*
5624 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5625 MIPS GNU/Linux mips*-*-linux*
5626 MIPS SGI Irix 6.x mips*-sgi-irix6*
5627 ia64 AIX ia64-*-aix*
5628 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5632 Motorola 68HC11 and 68HC12 m68hc11-elf
5634 UltraSparc running GNU/Linux sparc64-*-linux*
5636 * OBSOLETE configurations and files
5638 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5639 Harris/CXUX m88k m88*-harris-cxux*
5640 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5641 ns32k-utek-sysv* ns32k-utek-*
5642 TI TMS320C80 tic80-*-*
5644 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5645 PowerPC Solaris powerpcle-*-solaris*
5646 PowerPC Windows NT powerpcle-*-cygwin32
5647 PowerPC Netware powerpc-*-netware*
5648 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5649 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5650 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5651 Apple Macintosh (MPW) host N/A
5653 stuff.c (Program to stuff files into a specially prepared space in kdb)
5654 kdb-start.c (Main loop for the standalone kernel debugger)
5656 Configurations that have been declared obsolete in this release have
5657 been commented out. Unless there is activity to revive these
5658 configurations, the next release of GDB will have their sources
5659 permanently REMOVED.
5661 * REMOVED configurations and files
5663 Altos 3068 m68*-altos-*
5664 Convex c1-*-*, c2-*-*
5666 ARM RISCix arm-*-* (as host)
5670 * GDB has been converted to ISO C.
5672 GDB's source code has been converted to ISO C. In particular, the
5673 sources are fully protoized, and rely on standard headers being
5678 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5680 * The MI enabled by default.
5682 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5683 revised and enabled by default. Packages which use GDB as a debugging
5684 engine behind a UI or another front end are encouraged to switch to
5685 using the GDB/MI interface, instead of the old annotations interface
5686 which is now deprecated.
5688 * Support for debugging Pascal programs.
5690 GDB now includes support for debugging Pascal programs. The following
5691 main features are supported:
5693 - Pascal-specific data types such as sets;
5695 - automatic recognition of Pascal sources based on file-name
5698 - Pascal-style display of data types, variables, and functions;
5700 - a Pascal expression parser.
5702 However, some important features are not yet supported.
5704 - Pascal string operations are not supported at all;
5706 - there are some problems with boolean types;
5708 - Pascal type hexadecimal constants are not supported
5709 because they conflict with the internal variables format;
5711 - support for Pascal objects and classes is not full yet;
5713 - unlike Pascal, GDB is case-sensitive for symbol names.
5715 * Changes in completion.
5717 Commands such as `shell', `run' and `set args', which pass arguments
5718 to inferior programs, now complete on file names, similar to what
5719 users expect at the shell prompt.
5721 Commands which accept locations, such as `disassemble', `print',
5722 `breakpoint', `until', etc. now complete on filenames as well as
5723 program symbols. Thus, if you type "break foob TAB", and the source
5724 files linked into the programs include `foobar.c', that file name will
5725 be one of the candidates for completion. However, file names are not
5726 considered for completion after you typed a colon that delimits a file
5727 name from a name of a function in that file, as in "break foo.c:bar".
5729 `set demangle-style' completes on available demangling styles.
5731 * New platform-independent commands:
5733 It is now possible to define a post-hook for a command as well as a
5734 hook that runs before the command. For more details, see the
5735 documentation of `hookpost' in the GDB manual.
5737 * Changes in GNU/Linux native debugging.
5739 Support for debugging multi-threaded programs has been completely
5740 revised for all platforms except m68k and sparc. You can now debug as
5741 many threads as your system allows you to have.
5743 Attach/detach is supported for multi-threaded programs.
5745 Support for SSE registers was added for x86. This doesn't work for
5746 multi-threaded programs though.
5748 * Changes in MIPS configurations.
5750 Multi-arch support is enabled for all MIPS configurations.
5752 GDB can now be built as native debugger on SGI Irix 6.x systems for
5753 debugging n32 executables. (Debugging 64-bit executables is not yet
5756 * Unified support for hardware watchpoints in all x86 configurations.
5758 Most (if not all) native x86 configurations support hardware-assisted
5759 breakpoints and watchpoints in a unified manner. This support
5760 implements debug register sharing between watchpoints, which allows to
5761 put a virtually infinite number of watchpoints on the same address,
5762 and also supports watching regions up to 16 bytes with several debug
5765 The new maintenance command `maintenance show-debug-regs' toggles
5766 debugging print-outs in functions that insert, remove, and test
5767 watchpoints and hardware breakpoints.
5769 * Changes in the DJGPP native configuration.
5771 New command ``info dos sysinfo'' displays assorted information about
5772 the CPU, OS, memory, and DPMI server.
5774 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5775 display information about segment descriptors stored in GDT, LDT, and
5778 New commands ``info dos pde'' and ``info dos pte'' display entries
5779 from Page Directory and Page Tables (for now works with CWSDPMI only).
5780 New command ``info dos address-pte'' displays the Page Table entry for
5781 a given linear address.
5783 GDB can now pass command lines longer than 126 characters to the
5784 program being debugged (requires an update to the libdbg.a library
5785 which is part of the DJGPP development kit).
5787 DWARF2 debug info is now supported.
5789 It is now possible to `step' and `next' through calls to `longjmp'.
5791 * Changes in documentation.
5793 All GDB documentation was converted to GFDL, the GNU Free
5794 Documentation License.
5796 Tracepoints-related commands are now fully documented in the GDB
5799 TUI, the Text-mode User Interface, is now documented in the manual.
5801 Tracepoints-related commands are now fully documented in the GDB
5804 The "GDB Internals" manual now has an index. It also includes
5805 documentation of `ui_out' functions, GDB coding standards, x86
5806 hardware watchpoints, and memory region attributes.
5808 * GDB's version number moved to ``version.in''
5810 The Makefile variable VERSION has been replaced by the file
5811 ``version.in''. People creating GDB distributions should update the
5812 contents of this file.
5816 GUD support is now a standard part of the EMACS distribution.
5818 *** Changes in GDB 5.0:
5820 * Improved support for debugging FP programs on x86 targets
5822 Unified and much-improved support for debugging floating-point
5823 programs on all x86 targets. In particular, ``info float'' now
5824 displays the FP registers in the same format on all x86 targets, with
5825 greater level of detail.
5827 * Improvements and bugfixes in hardware-assisted watchpoints
5829 It is now possible to watch array elements, struct members, and
5830 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5831 on x86 targets no longer erroneously trigger when the address is
5834 * Improvements in the native DJGPP version of GDB
5836 The distribution now includes all the scripts and auxiliary files
5837 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5838 machines ``out of the box''.
5840 The DJGPP version can now debug programs that use signals. It is
5841 possible to catch signals that happened in the debuggee, deliver
5842 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5843 would kill the program being debugged.) Programs that hook hardware
5844 interrupts (keyboard, timer, etc.) can also be debugged.
5846 It is now possible to debug DJGPP programs that redirect their
5847 standard handles or switch them to raw (as opposed to cooked) mode, or
5848 even close them. The command ``run < foo > bar'' works as expected,
5849 and ``info terminal'' reports useful information about the debuggee's
5850 terminal, including raw/cooked mode, redirection, etc.
5852 The DJGPP version now uses termios functions for console I/O, which
5853 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5856 DOS-style file names with drive letters are now fully supported by
5859 It is now possible to debug DJGPP programs that switch their working
5860 directory. It is also possible to rerun the debuggee any number of
5861 times without restarting GDB; thus, you can use the same setup,
5862 breakpoints, etc. for many debugging sessions.
5864 * New native configurations
5866 ARM GNU/Linux arm*-*-linux*
5867 PowerPC GNU/Linux powerpc-*-linux*
5871 Motorola MCore mcore-*-*
5872 x86 VxWorks i[3456]86-*-vxworks*
5873 PowerPC VxWorks powerpc-*-vxworks*
5874 TI TMS320C80 tic80-*-*
5876 * OBSOLETE configurations
5878 Altos 3068 m68*-altos-*
5879 Convex c1-*-*, c2-*-*
5881 ARM RISCix arm-*-* (as host)
5884 Configurations that have been declared obsolete will be commented out,
5885 but the code will be left in place. If there is no activity to revive
5886 these configurations before the next release of GDB, the sources will
5887 be permanently REMOVED.
5889 * Gould support removed
5891 Support for the Gould PowerNode and NP1 has been removed.
5893 * New features for SVR4
5895 On SVR4 native platforms (such as Solaris), if you attach to a process
5896 without first loading a symbol file, GDB will now attempt to locate and
5897 load symbols from the running process's executable file.
5899 * Many C++ enhancements
5901 C++ support has been greatly improved. Overload resolution now works properly
5902 in almost all cases. RTTI support is on the way.
5904 * Remote targets can connect to a sub-program
5906 A popen(3) style serial-device has been added. This device starts a
5907 sub-process (such as a stand-alone simulator) and then communicates
5908 with that. The sub-program to run is specified using the syntax
5909 ``|<program> <args>'' vis:
5911 (gdb) set remotedebug 1
5912 (gdb) target extended-remote |mn10300-elf-sim program-args
5914 * MIPS 64 remote protocol
5916 A long standing bug in the mips64 remote protocol where by GDB
5917 expected certain 32 bit registers (ex SR) to be transfered as 32
5918 instead of 64 bits has been fixed.
5920 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5921 added to provide backward compatibility with older versions of GDB.
5923 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5925 The command ``set remotebinarydownload'' command has been replaced by
5926 ``set remote X-packet''. Other commands in ``set remote'' family
5927 include ``set remote P-packet''.
5929 * Breakpoint commands accept ranges.
5931 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5932 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5933 ``tracepoint passcount'' also accepts a range of tracepoints.
5935 * ``apropos'' command added.
5937 The ``apropos'' command searches through command names and
5938 documentation strings, printing out matches, making it much easier to
5939 try to find a command that does what you are looking for.
5943 A new machine oriented interface (MI) has been added to GDB. This
5944 interface is designed for debug environments running GDB as a separate
5945 process. This is part of the long term libGDB project. See the
5946 "GDB/MI" chapter of the GDB manual for further information. It can be
5947 enabled by configuring with:
5949 .../configure --enable-gdbmi
5951 *** Changes in GDB-4.18:
5953 * New native configurations
5955 HP-UX 10.20 hppa*-*-hpux10.20
5956 HP-UX 11.x hppa*-*-hpux11.0*
5957 M68K GNU/Linux m68*-*-linux*
5961 Fujitsu FR30 fr30-*-elf*
5962 Intel StrongARM strongarm-*-*
5963 Mitsubishi D30V d30v-*-*
5965 * OBSOLETE configurations
5967 Gould PowerNode, NP1 np1-*-*, pn-*-*
5969 Configurations that have been declared obsolete will be commented out,
5970 but the code will be left in place. If there is no activity to revive
5971 these configurations before the next release of GDB, the sources will
5972 be permanently REMOVED.
5976 As a compatibility experiment, GDB's source files buildsym.h and
5977 buildsym.c have been converted to pure standard C, no longer
5978 containing any K&R compatibility code. We believe that all systems in
5979 use today either come with a standard C compiler, or have a GCC port
5980 available. If this is not true, please report the affected
5981 configuration to bug-gdb@gnu.org immediately. See the README file for
5982 information about getting a standard C compiler if you don't have one
5987 GDB now uses readline 2.2.
5989 * set extension-language
5991 You can now control the mapping between filename extensions and source
5992 languages by using the `set extension-language' command. For instance,
5993 you can ask GDB to treat .c files as C++ by saying
5994 set extension-language .c c++
5995 The command `info extensions' lists all of the recognized extensions
5996 and their associated languages.
5998 * Setting processor type for PowerPC and RS/6000
6000 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6001 you can use the `set processor' command to specify what variant of the
6002 PowerPC family you are debugging. The command
6006 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6007 following PowerPC and RS6000 variants:
6009 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6010 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6012 403GC IBM PowerPC 403GC
6013 505 Motorola PowerPC 505
6014 860 Motorola PowerPC 860 or 850
6015 601 Motorola PowerPC 601
6016 602 Motorola PowerPC 602
6017 603 Motorola/IBM PowerPC 603 or 603e
6018 604 Motorola PowerPC 604 or 604e
6019 750 Motorola/IBM PowerPC 750 or 750
6021 At the moment, this command just tells GDB what to name the
6022 special-purpose processor registers. Since almost all the affected
6023 registers are inaccessible to user-level programs, this command is
6024 only useful for remote debugging in its present form.
6028 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6029 more extensive support for HP-UX. Added features include shared
6030 library support, kernel threads and hardware watchpoints for 11.00,
6031 support for HP's ANSI C and C++ compilers, and a compatibility mode
6032 for xdb and dbx commands.
6036 HP's donation includes the new concept of catchpoints, which is a
6037 generalization of the old catch command. On HP-UX, it is now possible
6038 to catch exec, fork, and vfork, as well as library loading.
6040 This means that the existing catch command has changed; its first
6041 argument now specifies the type of catch to be set up. See the
6042 output of "help catch" for a list of catchpoint types.
6044 * Debugging across forks
6046 On HP-UX, you can choose which process to debug when a fork() happens
6051 HP has donated a curses-based terminal user interface (TUI). To get
6052 it, build with --enable-tui. Although this can be enabled for any
6053 configuration, at present it only works for native HP debugging.
6055 * GDB remote protocol additions
6057 A new protocol packet 'X' that writes binary data is now available.
6058 Default behavior is to try 'X', then drop back to 'M' if the stub
6059 fails to respond. The settable variable `remotebinarydownload'
6060 allows explicit control over the use of 'X'.
6062 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6063 full 64-bit address. The command
6065 set remoteaddresssize 32
6067 can be used to revert to the old behaviour. For existing remote stubs
6068 the change should not be noticed, as the additional address information
6071 In order to assist in debugging stubs, you may use the maintenance
6072 command `packet' to send any text string to the stub. For instance,
6074 maint packet heythere
6076 sends the packet "$heythere#<checksum>". Note that it is very easy to
6077 disrupt a debugging session by sending the wrong packet at the wrong
6080 The compare-sections command allows you to compare section data on the
6081 target to what is in the executable file without uploading or
6082 downloading, by comparing CRC checksums.
6084 * Tracing can collect general expressions
6086 You may now collect general expressions at tracepoints. This requires
6087 further additions to the target-side stub; see tracepoint.c and
6088 doc/agentexpr.texi for further details.
6090 * mask-address variable for Mips
6092 For Mips targets, you may control the zeroing of the upper 32 bits of
6093 a 64-bit address by entering `set mask-address on'. This is mainly
6094 of interest to users of embedded R4xxx and R5xxx processors.
6096 * Higher serial baud rates
6098 GDB's serial code now allows you to specify baud rates 57600, 115200,
6099 230400, and 460800 baud. (Note that your host system may not be able
6100 to achieve all of these rates.)
6104 The i960 configuration now includes an initial implementation of a
6105 builtin simulator, contributed by Jim Wilson.
6108 *** Changes in GDB-4.17:
6110 * New native configurations
6112 Alpha GNU/Linux alpha*-*-linux*
6113 Unixware 2.x i[3456]86-unixware2*
6114 Irix 6.x mips*-sgi-irix6*
6115 PowerPC GNU/Linux powerpc-*-linux*
6116 PowerPC Solaris powerpcle-*-solaris*
6117 Sparc GNU/Linux sparc-*-linux*
6118 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6122 Argonaut Risc Chip (ARC) arc-*-*
6123 Hitachi H8/300S h8300*-*-*
6124 Matsushita MN10200 w/simulator mn10200-*-*
6125 Matsushita MN10300 w/simulator mn10300-*-*
6126 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6127 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6128 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6129 Mitsubishi D10V w/simulator d10v-*-*
6130 Mitsubishi M32R/D w/simulator m32r-*-elf*
6131 Tsqware Sparclet sparclet-*-*
6132 NEC V850 w/simulator v850-*-*
6134 * New debugging protocols
6136 ARM with RDI protocol arm*-*-*
6137 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6138 DDB and LSI variants of PMON protocol mips*-*-*
6139 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6140 PowerPC with SDS protocol powerpc{,le}-*-eabi
6141 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6145 All configurations can now understand and use the DWARF 2 debugging
6146 format. The choice is automatic, if the symbol file contains DWARF 2
6151 GDB now includes basic Java language support. This support is
6152 only useful with Java compilers that produce native machine code.
6154 * solib-absolute-prefix and solib-search-path
6156 For SunOS and SVR4 shared libraries, you may now set the prefix for
6157 loading absolute shared library symbol files, and the search path for
6158 locating non-absolute shared library symbol files.
6160 * Live range splitting
6162 GDB can now effectively debug code for which GCC has performed live
6163 range splitting as part of its optimization. See gdb/doc/LRS for
6164 more details on the expected format of the stabs information.
6168 GDB's support for the GNU Hurd, including thread debugging, has been
6169 updated to work with current versions of the Hurd.
6173 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6174 instruction set. ARM GDB automatically detects when Thumb
6175 instructions are in use, and adjusts disassembly and backtracing
6180 GDB's MIPS target configurations now handle the MIP16 16-bit
6185 GDB now includes support for overlays; if an executable has been
6186 linked such that multiple sections are based at the same address, GDB
6187 will decide which section to use for symbolic info. You can choose to
6188 control the decision manually, using overlay commands, or implement
6189 additional target-side support and use "overlay load-target" to bring
6190 in the overlay mapping. Do "help overlay" for more detail.
6194 The command "info symbol <address>" displays information about
6195 the symbol at the specified address.
6199 The standard remote protocol now includes an extension that allows
6200 asynchronous collection and display of trace data. This requires
6201 extensive support in the target-side debugging stub. Tracing mode
6202 includes a new interaction mode in GDB and new commands: see the
6203 file tracepoint.c for more details.
6207 Configurations for embedded MIPS now include a simulator contributed
6208 by Cygnus Solutions. The simulator supports the instruction sets
6209 of most MIPS variants.
6213 Sparc configurations may now include the ERC32 simulator contributed
6214 by the European Space Agency. The simulator is not built into
6215 Sparc targets by default; configure with --enable-sim to include it.
6219 For target configurations that may include multiple variants of a
6220 basic architecture (such as MIPS and SH), you may now set the
6221 architecture explicitly. "set arch" sets, "info arch" lists
6222 the possible architectures.
6224 *** Changes in GDB-4.16:
6226 * New native configurations
6228 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6229 M68K NetBSD m68k-*-netbsd*
6230 PowerPC AIX 4.x powerpc-*-aix*
6231 PowerPC MacOS powerpc-*-macos*
6232 PowerPC Windows NT powerpcle-*-cygwin32
6233 RS/6000 AIX 4.x rs6000-*-aix4*
6237 ARM with RDP protocol arm-*-*
6238 I960 with MON960 i960-*-coff
6239 MIPS VxWorks mips*-*-vxworks*
6240 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6241 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6243 Matra Sparclet sparclet-*-*
6247 The powerpc-eabi configuration now includes the PSIM simulator,
6248 contributed by Andrew Cagney, with assistance from Mike Meissner.
6249 PSIM is a very elaborate model of the PowerPC, including not only
6250 basic instruction set execution, but also details of execution unit
6251 performance and I/O hardware. See sim/ppc/README for more details.
6255 GDB now works with Solaris 2.5.
6257 * Windows 95/NT native
6259 GDB will now work as a native debugger on Windows 95 and Windows NT.
6260 To build it from source, you must use the "gnu-win32" environment,
6261 which uses a DLL to emulate enough of Unix to run the GNU tools.
6262 Further information, binaries, and sources are available at
6263 ftp.cygnus.com, under pub/gnu-win32.
6265 * dont-repeat command
6267 If a user-defined command includes the command `dont-repeat', then the
6268 command will not be repeated if the user just types return. This is
6269 useful if the command is time-consuming to run, so that accidental
6270 extra keystrokes don't run the same command many times.
6272 * Send break instead of ^C
6274 The standard remote protocol now includes an option to send a break
6275 rather than a ^C to the target in order to interrupt it. By default,
6276 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6278 * Remote protocol timeout
6280 The standard remote protocol includes a new variable `remotetimeout'
6281 that allows you to set the number of seconds before GDB gives up trying
6282 to read from the target. The default value is 2.
6284 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6286 By default GDB will automatically keep track of objects as they are
6287 loaded and unloaded by the dynamic linker. By using the command `set
6288 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6289 when shared library events occur, thus allowing you to set breakpoints
6290 in shared libraries which are explicitly loaded by the inferior.
6292 Note this feature does not work on hpux8. On hpux9 you must link
6293 /usr/lib/end.o into your program. This feature should work
6294 automatically on hpux10.
6296 * Irix 5.x hardware watchpoint support
6298 Irix 5 configurations now support the use of hardware watchpoints.
6300 * Mips protocol "SYN garbage limit"
6302 When debugging a Mips target using the `target mips' protocol, you
6303 may set the number of characters that GDB will ignore by setting
6304 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6305 every character. The default value is 1050.
6307 * Recording and replaying remote debug sessions
6309 If you set `remotelogfile' to the name of a file, gdb will write to it
6310 a recording of a remote debug session. This recording may then be
6311 replayed back to gdb using "gdbreplay". See gdbserver/README for
6312 details. This is useful when you have a problem with GDB while doing
6313 remote debugging; you can make a recording of the session and send it
6314 to someone else, who can then recreate the problem.
6316 * Speedups for remote debugging
6318 GDB includes speedups for downloading and stepping MIPS systems using
6319 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6320 and more efficient S-record downloading.
6322 * Memory use reductions and statistics collection
6324 GDB now uses less memory and reports statistics about memory usage.
6325 Try the `maint print statistics' command, for example.
6327 *** Changes in GDB-4.15:
6329 * Psymtabs for XCOFF
6331 The symbol reader for AIX GDB now uses partial symbol tables. This
6332 can greatly improve startup time, especially for large executables.
6334 * Remote targets use caching
6336 Remote targets now use a data cache to speed up communication with the
6337 remote side. The data cache could lead to incorrect results because
6338 it doesn't know about volatile variables, thus making it impossible to
6339 debug targets which use memory mapped I/O devices. `set remotecache
6340 off' turns the the data cache off.
6342 * Remote targets may have threads
6344 The standard remote protocol now includes support for multiple threads
6345 in the target system, using new protocol commands 'H' and 'T'. See
6346 gdb/remote.c for details.
6350 If GDB is configured with `--enable-netrom', then it will include
6351 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6352 acts as though it is a bank of ROM on the target board, but you can
6353 write into it over the network. GDB's support consists only of
6354 support for fast loading into the emulated ROM; to debug, you must use
6355 another protocol, such as standard remote protocol. The usual
6356 sequence is something like
6358 target nrom <netrom-hostname>
6360 target remote <netrom-hostname>:1235
6364 GDB now includes support for the Apple Macintosh, as a host only. It
6365 may be run as either an MPW tool or as a standalone application, and
6366 it can debug through the serial port. All the usual GDB commands are
6367 available, but to the target command, you must supply "serial" as the
6368 device type instead of "/dev/ttyXX". See mpw-README in the main
6369 directory for more information on how to build. The MPW configuration
6370 scripts */mpw-config.in support only a few targets, and only the
6371 mips-idt-ecoff target has been tested.
6375 GDB configuration now uses autoconf. This is not user-visible,
6376 but does simplify configuration and building.
6380 GDB now supports hpux10.
6382 *** Changes in GDB-4.14:
6384 * New native configurations
6386 x86 FreeBSD i[345]86-*-freebsd
6387 x86 NetBSD i[345]86-*-netbsd
6388 NS32k NetBSD ns32k-*-netbsd
6389 Sparc NetBSD sparc-*-netbsd
6393 A29K VxWorks a29k-*-vxworks
6394 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6395 CPU32 EST-300 emulator m68*-*-est*
6396 PowerPC ELF powerpc-*-elf
6399 * Alpha OSF/1 support for procfs
6401 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6402 possible to attach to running processes. As the mounting of the /proc
6403 filesystem is optional on the Alpha, GDB automatically determines
6404 the availability of /proc during startup. This can lead to problems
6405 if /proc is unmounted after GDB has been started.
6407 * Arguments to user-defined commands
6409 User commands may accept up to 10 arguments separated by whitespace.
6410 Arguments are accessed within the user command via $arg0..$arg9. A
6413 print $arg0 + $arg1 + $arg2
6415 To execute the command use:
6418 Defines the command "adder" which prints the sum of its three arguments.
6419 Note the arguments are text substitutions, so they may reference variables,
6420 use complex expressions, or even perform inferior function calls.
6422 * New `if' and `while' commands
6424 This makes it possible to write more sophisticated user-defined
6425 commands. Both commands take a single argument, which is the
6426 expression to evaluate, and must be followed by the commands to
6427 execute, one per line, if the expression is nonzero, the list being
6428 terminated by the word `end'. The `if' command list may include an
6429 `else' word, which causes the following commands to be executed only
6430 if the expression is zero.
6432 * Fortran source language mode
6434 GDB now includes partial support for Fortran 77. It will recognize
6435 Fortran programs and can evaluate a subset of Fortran expressions, but
6436 variables and functions may not be handled correctly. GDB will work
6437 with G77, but does not yet know much about symbols emitted by other
6440 * Better HPUX support
6442 Most debugging facilities now work on dynamic executables for HPPAs
6443 running hpux9 or later. You can attach to running dynamically linked
6444 processes, but by default the dynamic libraries will be read-only, so
6445 for instance you won't be able to put breakpoints in them. To change
6446 that behavior do the following before running the program:
6452 This will cause the libraries to be mapped private and read-write.
6453 To revert to the normal behavior, do this:
6459 You cannot set breakpoints or examine data in the library until after
6460 the library is loaded if the function/data symbols do not have
6463 GDB can now also read debug symbols produced by the HP C compiler on
6464 HPPAs (sorry, no C++, Fortran or 68k support).
6466 * Target byte order now dynamically selectable
6468 You can choose which byte order to use with a target system, via the
6469 commands "set endian big" and "set endian little", and you can see the
6470 current setting by using "show endian". You can also give the command
6471 "set endian auto", in which case GDB will use the byte order
6472 associated with the executable. Currently, only embedded MIPS
6473 configurations support dynamic selection of target byte order.
6475 * New DOS host serial code
6477 This version uses DPMI interrupts to handle buffered I/O, so you
6478 no longer need to run asynctsr when debugging boards connected to
6481 *** Changes in GDB-4.13:
6483 * New "complete" command
6485 This lists all the possible completions for the rest of the line, if it
6486 were to be given as a command itself. This is intended for use by emacs.
6488 * Trailing space optional in prompt
6490 "set prompt" no longer adds a space for you after the prompt you set. This
6491 allows you to set a prompt which ends in a space or one that does not.
6493 * Breakpoint hit counts
6495 "info break" now displays a count of the number of times the breakpoint
6496 has been hit. This is especially useful in conjunction with "ignore"; you
6497 can ignore a large number of breakpoint hits, look at the breakpoint info
6498 to see how many times the breakpoint was hit, then run again, ignoring one
6499 less than that number, and this will get you quickly to the last hit of
6502 * Ability to stop printing at NULL character
6504 "set print null-stop" will cause GDB to stop printing the characters of
6505 an array when the first NULL is encountered. This is useful when large
6506 arrays actually contain only short strings.
6508 * Shared library breakpoints
6510 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6511 breakpoints in shared libraries before the executable is run.
6513 * Hardware watchpoints
6515 There is a new hardware breakpoint for the watch command for sparclite
6516 targets. See gdb/sparclite/hw_breakpoint.note.
6518 Hardware watchpoints are also now supported under GNU/Linux.
6522 Annotations have been added. These are for use with graphical interfaces,
6523 and are still experimental. Currently only gdba.el uses these.
6525 * Improved Irix 5 support
6527 GDB now works properly with Irix 5.2.
6529 * Improved HPPA support
6531 GDB now works properly with the latest GCC and GAS.
6533 * New native configurations
6535 Sequent PTX4 i[34]86-sequent-ptx4
6536 HPPA running OSF/1 hppa*-*-osf*
6537 Atari TT running SVR4 m68*-*-sysv4*
6538 RS/6000 LynxOS rs6000-*-lynxos*
6542 OS/9000 i[34]86-*-os9k
6543 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6546 * Hitachi SH7000 and E7000-PC ICE support
6548 There is now support for communicating with the Hitachi E7000-PC ICE.
6549 This is available automatically when GDB is configured for the SH.
6553 As usual, a variety of small fixes and improvements, both generic
6554 and configuration-specific. See the ChangeLog for more detail.
6556 *** Changes in GDB-4.12:
6558 * Irix 5 is now supported
6562 GDB-4.12 on the HPPA has a number of changes which make it unable
6563 to debug the output from the currently released versions of GCC and
6564 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6565 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6566 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6569 *** Changes in GDB-4.11:
6571 * User visible changes:
6575 The "set remotedebug" option is now consistent between the mips remote
6576 target, remote targets using the gdb-specific protocol, UDI (AMD's
6577 debug protocol for the 29k) and the 88k bug monitor. It is now an
6578 integer specifying a debug level (normally 0 or 1, but 2 means more
6579 debugging info for the mips target).
6581 * DEC Alpha native support
6583 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6584 debug info, but GDB works fairly well with the DEC compiler and should
6585 work with a future GCC release. See the README file for a few
6586 Alpha-specific notes.
6588 * Preliminary thread implementation
6590 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6592 * LynxOS native and target support for 386
6594 This release has been hosted on LynxOS 2.2, and also can be configured
6595 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6598 * Improvements in C++ mangling/demangling.
6600 This release has much better g++ debugging, specifically in name
6601 mangling/demangling, virtual function calls, print virtual table,
6602 call methods, ...etc.
6604 *** Changes in GDB-4.10:
6606 * User visible changes:
6608 Remote debugging using the GDB-specific (`target remote') protocol now
6609 supports the `load' command. This is only useful if you have some
6610 other way of getting the stub to the target system, and you can put it
6611 somewhere in memory where it won't get clobbered by the download.
6613 Filename completion now works.
6615 When run under emacs mode, the "info line" command now causes the
6616 arrow to point to the line specified. Also, "info line" prints
6617 addresses in symbolic form (as well as hex).
6619 All vxworks based targets now support a user settable option, called
6620 vxworks-timeout. This option represents the number of seconds gdb
6621 should wait for responses to rpc's. You might want to use this if
6622 your vxworks target is, perhaps, a slow software simulator or happens
6623 to be on the far side of a thin network line.
6627 This release contains support for using a DEC alpha as a GDB host for
6628 cross debugging. Native alpha debugging is not supported yet.
6631 *** Changes in GDB-4.9:
6635 This is the first GDB release which is accompanied by a matching testsuite.
6636 The testsuite requires installation of dejagnu, which should be available
6637 via ftp from most sites that carry GNU software.
6641 'Cfront' style demangling has had its name changed to 'ARM' style, to
6642 emphasize that it was written from the specifications in the C++ Annotated
6643 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6644 disclaimers, it still generated too much confusion with users attempting to
6645 use gdb with AT&T cfront.
6649 GDB now uses a standard remote interface to a simulator library.
6650 So far, the library contains simulators for the Zilog Z8001/2, the
6651 Hitachi H8/300, H8/500 and Super-H.
6653 * New targets supported
6655 H8/300 simulator h8300-hitachi-hms or h8300hms
6656 H8/500 simulator h8500-hitachi-hms or h8500hms
6657 SH simulator sh-hitachi-hms or sh
6658 Z8000 simulator z8k-zilog-none or z8ksim
6659 IDT MIPS board over serial line mips-idt-ecoff
6661 Cross-debugging to GO32 targets is supported. It requires a custom
6662 version of the i386-stub.c module which is integrated with the
6663 GO32 memory extender.
6665 * New remote protocols
6667 MIPS remote debugging protocol.
6669 * New source languages supported
6671 This version includes preliminary support for Chill, a Pascal like language
6672 used by telecommunications companies. Chill support is also being integrated
6673 into the GNU compiler, but we don't know when it will be publically available.
6676 *** Changes in GDB-4.8:
6678 * HP Precision Architecture supported
6680 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6681 version of this support was available as a set of patches from the
6682 University of Utah. GDB does not support debugging of programs
6683 compiled with the HP compiler, because HP will not document their file
6684 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6685 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6687 Many problems in the preliminary version have been fixed.
6689 * Faster and better demangling
6691 We have improved template demangling and fixed numerous bugs in the GNU style
6692 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6693 character types (wchar_t) are now supported. Demangling of each symbol is now
6694 only done once, and is cached when the symbol table for a file is read in.
6695 This results in a small increase in memory usage for C programs, a moderate
6696 increase in memory usage for C++ programs, and a fantastic speedup in
6699 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6700 from the specifications in the Annotated Reference Manual, which AT&T's
6701 compiler does not actually implement.
6703 * G++ multiple inheritance compiler problem
6705 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6706 inheritance lattices was reworked to properly discover ambiguities. We
6707 recently found an example which causes this new algorithm to fail in a
6708 very subtle way, producing bad debug information for those classes.
6709 The file 'gcc.patch' (in this directory) can be applied to gcc to
6710 circumvent the problem. A future GCC release will contain a complete
6713 The previous G++ debug info problem (mentioned below for the gdb-4.7
6714 release) is fixed in gcc version 2.3.2.
6716 * Improved configure script
6718 The `configure' script will now attempt to guess your system type if
6719 you don't supply a host system type. The old scheme of supplying a
6720 host system triplet is preferable over using this. All the magic is
6721 done in the new `config.guess' script. Examine it for details.
6723 We have also brought our configure script much more in line with the FSF's
6724 version. It now supports the --with-xxx options. In particular,
6725 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6726 The resulting GDB will not be able to read arbitrary object file formats --
6727 only the format ``expected'' to be used on the configured target system.
6728 We hope to make this the default in a future release.
6730 * Documentation improvements
6732 There's new internal documentation on how to modify GDB, and how to
6733 produce clean changes to the code. We implore people to read it
6734 before submitting changes.
6736 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6737 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6738 `info' files are also provided. To build `info' files from scratch,
6739 you will need the latest `makeinfo' release, which will be available in
6740 a future texinfo-X.Y release.
6742 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6743 We're not sure exactly which versions have this problem, but it has
6744 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6745 or better. If that isn't possible, there is a patch in
6746 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6747 around this problem.
6751 GDB now supports array constants that can be used in expressions typed in by
6752 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6753 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6756 The new directory `gdb/sparclite' contains a program that demonstrates
6757 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6759 * New native hosts supported
6761 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6762 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6764 * New targets supported
6766 AMD 29k family via UDI a29k-amd-udi or udi29k
6768 * New file formats supported
6770 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6771 HPUX core files, and SCO 3.2v2 core files.
6775 Attaching to processes now works again; thanks for the many bug reports.
6777 We have also stomped on a bunch of core dumps caused by
6778 printf_filtered("%s") problems.
6780 We eliminated a copyright problem on the rpc and ptrace header files
6781 for VxWorks, which was discovered at the last minute during the 4.7
6782 release. You should now be able to build a VxWorks GDB.
6784 You can now interrupt gdb while an attached process is running. This
6785 will cause the attached process to stop, and give control back to GDB.
6787 We fixed problems caused by using too many file descriptors
6788 for reading symbols from object files and libraries. This was
6789 especially a problem for programs that used many (~100) shared
6792 The `step' command now only enters a subroutine if there is line number
6793 information for the subroutine. Otherwise it acts like the `next'
6794 command. Previously, `step' would enter subroutines if there was
6795 any debugging information about the routine. This avoids problems
6796 when using `cc -g1' on MIPS machines.
6798 * Internal improvements
6800 GDB's internal interfaces have been improved to make it easier to support
6801 debugging of multiple languages in the future.
6803 GDB now uses a common structure for symbol information internally.
6804 Minimal symbols (derived from linkage symbols in object files), partial
6805 symbols (from a quick scan of debug information), and full symbols
6806 contain a common subset of information, making it easier to write
6807 shared code that handles any of them.
6809 * New command line options
6811 We now accept --silent as an alias for --quiet.
6815 The memory-mapped-malloc library is now licensed under the GNU Library
6816 General Public License.
6818 *** Changes in GDB-4.7:
6820 * Host/native/target split
6822 GDB has had some major internal surgery to untangle the support for
6823 hosts and remote targets. Now, when you configure GDB for a remote
6824 target, it will no longer load in all of the support for debugging
6825 local programs on the host. When fully completed and tested, this will
6826 ensure that arbitrary host/target combinations are possible.
6828 The primary conceptual shift is to separate the non-portable code in
6829 GDB into three categories. Host specific code is required any time GDB
6830 is compiled on that host, regardless of the target. Target specific
6831 code relates to the peculiarities of the target, but can be compiled on
6832 any host. Native specific code is everything else: it can only be
6833 built when the host and target are the same system. Child process
6834 handling and core file support are two common `native' examples.
6836 GDB's use of /proc for controlling Unix child processes is now cleaner.
6837 It has been split out into a single module under the `target_ops' vector,
6838 plus two native-dependent functions for each system that uses /proc.
6840 * New hosts supported
6842 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6843 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6844 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6846 * New targets supported
6848 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6849 68030 and CPU32 m68030-*-*, m68332-*-*
6851 * New native hosts supported
6853 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6854 (386bsd is not well tested yet)
6855 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6857 * New file formats supported
6859 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6860 supports reading of `a.out.adobe' object files, which are an a.out
6861 format extended with minimal information about multiple sections.
6865 `show copying' is the same as the old `info copying'.
6866 `show warranty' is the same as `info warrantee'.
6867 These were renamed for consistency. The old commands continue to work.
6869 `info handle' is a new alias for `info signals'.
6871 You can now define pre-command hooks, which attach arbitrary command
6872 scripts to any command. The commands in the hook will be executed
6873 prior to the user's command. You can also create a hook which will be
6874 executed whenever the program stops. See gdb.texinfo.
6878 We now deal with Cfront style name mangling, and can even extract type
6879 info from mangled symbols. GDB can automatically figure out which
6880 symbol mangling style your C++ compiler uses.
6882 Calling of methods and virtual functions has been improved as well.
6886 The crash that occured when debugging Sun Ansi-C compiled binaries is
6887 fixed. This was due to mishandling of the extra N_SO stabs output
6890 We also finally got Ultrix 4.2 running in house, and fixed core file
6891 support, with help from a dozen people on the net.
6893 John M. Farrell discovered that the reason that single-stepping was so
6894 slow on all of the Mips based platforms (primarily SGI and DEC) was
6895 that we were trying to demangle and lookup a symbol used for internal
6896 purposes on every instruction that was being stepped through. Changing
6897 the name of that symbol so that it couldn't be mistaken for a C++
6898 mangled symbol sped things up a great deal.
6900 Rich Pixley sped up symbol lookups in general by getting much smarter
6901 about when C++ symbol mangling is necessary. This should make symbol
6902 completion (TAB on the command line) much faster. It's not as fast as
6903 we'd like, but it's significantly faster than gdb-4.6.
6907 A new user controllable variable 'call_scratch_address' can
6908 specify the location of a scratch area to be used when GDB
6909 calls a function in the target. This is necessary because the
6910 usual method of putting the scratch area on the stack does not work
6911 in systems that have separate instruction and data spaces.
6913 We integrated changes to support the 29k UDI (Universal Debugger
6914 Interface), but discovered at the last minute that we didn't have all
6915 of the appropriate copyright paperwork. We are working with AMD to
6916 resolve this, and hope to have it available soon.
6920 We have sped up the remote serial line protocol, especially for targets
6921 with lots of registers. It now supports a new `expedited status' ('T')
6922 message which can be used in place of the existing 'S' status message.
6923 This allows the remote stub to send only the registers that GDB
6924 needs to make a quick decision about single-stepping or conditional
6925 breakpoints, eliminating the need to fetch the entire register set for
6926 each instruction being stepped through.
6928 The GDB remote serial protocol now implements a write-through cache for
6929 registers, only re-reading the registers if the target has run.
6931 There is also a new remote serial stub for SPARC processors. You can
6932 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6933 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6934 processor with a serial port.
6938 Configure.in files have become much easier to read and modify. A new
6939 `table driven' format makes it more obvious what configurations are
6940 supported, and what files each one uses.
6944 There is a new opcodes library which will eventually contain all of the
6945 disassembly routines and opcode tables. At present, it only contains
6946 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6947 disassembler (binutils/objdump) to share these routines.
6949 The libiberty library is now copylefted under the GNU Library General
6950 Public License. This allows more liberal use, and was done so libg++
6951 can use it. This makes no difference to GDB, since the Library License
6952 grants all the rights from the General Public License.
6956 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6957 reference to the stabs symbol info used by the debugger. It is (as far
6958 as we know) the only published document on this fascinating topic. We
6959 encourage you to read it, compare it to the stabs information on your
6960 system, and send improvements on the document in general (to
6961 bug-gdb@prep.ai.mit.edu).
6963 And, of course, many bugs have been fixed.
6966 *** Changes in GDB-4.6:
6968 * Better support for C++ function names
6970 GDB now accepts as input the "demangled form" of C++ overloaded function
6971 names and member function names, and can do command completion on such names
6972 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6973 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6974 Make use of command completion, it is your friend.
6976 GDB also now accepts a variety of C++ mangled symbol formats. They are
6977 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6978 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6979 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6980 for the list of formats.
6982 * G++ symbol mangling problem
6984 Recent versions of gcc have a bug in how they emit debugging information for
6985 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6986 directory) can be applied to gcc to fix the problem. Alternatively, if you
6987 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6988 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6989 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6992 * New 'maintenance' command
6994 All of the commands related to hacking GDB internals have been moved out of
6995 the main command set, and now live behind the 'maintenance' command. This
6996 can also be abbreviated as 'mt'. The following changes were made:
6998 dump-me -> maintenance dump-me
6999 info all-breakpoints -> maintenance info breakpoints
7000 printmsyms -> maintenance print msyms
7001 printobjfiles -> maintenance print objfiles
7002 printpsyms -> maintenance print psymbols
7003 printsyms -> maintenance print symbols
7005 The following commands are new:
7007 maintenance demangle Call internal GDB demangler routine to
7008 demangle a C++ link name and prints the result.
7009 maintenance print type Print a type chain for a given symbol
7011 * Change to .gdbinit file processing
7013 We now read the $HOME/.gdbinit file before processing the argv arguments
7014 (e.g. reading symbol files or core files). This allows global parameters to
7015 be set, which will apply during the symbol reading. The ./.gdbinit is still
7016 read after argv processing.
7018 * New hosts supported
7020 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7022 GNU/Linux support i386-unknown-linux or linux
7024 We are also including code to support the HP/PA running BSD and HPUX. This
7025 is almost guaranteed not to work, as we didn't have time to test or build it
7026 for this release. We are including it so that the more adventurous (or
7027 masochistic) of you can play with it. We also had major problems with the
7028 fact that the compiler that we got from HP doesn't support the -g option.
7031 * New targets supported
7033 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7035 * More smarts about finding #include files
7037 GDB now remembers the compilation directory for all include files, and for
7038 all files from which C is generated (like yacc and lex sources). This
7039 greatly improves GDB's ability to find yacc/lex sources, and include files,
7040 especially if you are debugging your program from a directory different from
7041 the one that contains your sources.
7043 We also fixed a bug which caused difficulty with listing and setting
7044 breakpoints in include files which contain C code. (In the past, you had to
7045 try twice in order to list an include file that you hadn't looked at before.)
7047 * Interesting infernals change
7049 GDB now deals with arbitrary numbers of sections, where the symbols for each
7050 section must be relocated relative to that section's landing place in the
7051 target's address space. This work was needed to support ELF with embedded
7052 stabs used by Solaris-2.0.
7054 * Bug fixes (of course!)
7056 There have been loads of fixes for the following things:
7057 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7058 i960, stabs, DOS(GO32), procfs, etc...
7060 See the ChangeLog for details.
7062 *** Changes in GDB-4.5:
7064 * New machines supported (host and target)
7066 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7068 SGI Irix-4.x mips-sgi-irix4 or iris4
7070 * New malloc package
7072 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7073 Mmalloc is capable of handling mutiple heaps of memory. It is also
7074 capable of saving a heap to a file, and then mapping it back in later.
7075 This can be used to greatly speedup the startup of GDB by using a
7076 pre-parsed symbol table which lives in a mmalloc managed heap. For
7077 more details, please read mmalloc/mmalloc.texi.
7081 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7082 'help info proc' for details.
7084 * MIPS ecoff symbol table format
7086 The code that reads MIPS symbol table format is now supported on all hosts.
7087 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7090 * File name changes for MS-DOS
7092 Many files in the config directories have been renamed to make it easier to
7093 support GDB on MS-DOSe systems (which have very restrictive file name
7094 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7095 environment) is close to working but has some remaining problems. Note
7096 that debugging of DOS programs is not supported, due to limitations
7097 in the ``operating system'', but it can be used to host cross-debugging.
7099 * Cross byte order fixes
7101 Many fixes have been made to support cross debugging of Sparc and MIPS
7102 targets from hosts whose byte order differs.
7104 * New -mapped and -readnow options
7106 If memory-mapped files are available on your system through the 'mmap'
7107 system call, you can use the -mapped option on the `file' or
7108 `symbol-file' commands to cause GDB to write the symbols from your
7109 program into a reusable file. If the program you are debugging is
7110 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7111 Future GDB debugging sessions will notice the presence of this file,
7112 and will quickly map in symbol information from it, rather than reading
7113 the symbol table from the executable program. Using the '-mapped'
7114 option in a GDB `file' or `symbol-file' command has the same effect as
7115 starting GDB with the '-mapped' command-line option.
7117 You can cause GDB to read the entire symbol table immediately by using
7118 the '-readnow' option with any of the commands that load symbol table
7119 information (or on the GDB command line). This makes the command
7120 slower, but makes future operations faster.
7122 The -mapped and -readnow options are typically combined in order to
7123 build a `fred.syms' file that contains complete symbol information.
7124 A simple GDB invocation to do nothing but build a `.syms' file for future
7127 gdb -batch -nx -mapped -readnow programname
7129 The `.syms' file is specific to the host machine on which GDB is run.
7130 It holds an exact image of GDB's internal symbol table. It cannot be
7131 shared across multiple host platforms.
7133 * longjmp() handling
7135 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7136 siglongjmp() without losing control. This feature has not yet been ported to
7137 all systems. It currently works on many 386 platforms, all MIPS-based
7138 platforms (SGI, DECstation, etc), and Sun3/4.
7142 Preliminary work has been put in to support the new Solaris OS from Sun. At
7143 this time, it can control and debug processes, but it is not capable of
7148 As always, many many bug fixes. The major areas were with g++, and mipsread.
7149 People using the MIPS-based platforms should experience fewer mysterious
7150 crashes and trashed symbol tables.
7152 *** Changes in GDB-4.4:
7154 * New machines supported (host and target)
7156 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7158 BSD Reno on Vax vax-dec-bsd
7159 Ultrix on Vax vax-dec-ultrix
7161 * New machines supported (target)
7163 AMD 29000 embedded, using EBMON a29k-none-none
7167 GDB continues to improve its handling of C++. `References' work better.
7168 The demangler has also been improved, and now deals with symbols mangled as
7169 per the Annotated C++ Reference Guide.
7171 GDB also now handles `stabs' symbol information embedded in MIPS
7172 `ecoff' symbol tables. Since the ecoff format was not easily
7173 extensible to handle new languages such as C++, this appeared to be a
7174 good way to put C++ debugging info into MIPS binaries. This option
7175 will be supported in the GNU C compiler, version 2, when it is
7178 * New features for SVR4
7180 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7181 shared libraries. Debugging dynamically linked programs should present
7182 only minor differences from debugging statically linked programs.
7184 The `info proc' command will print out information about any process
7185 on an SVR4 system (including the one you are debugging). At the moment,
7186 it prints the address mappings of the process.
7188 If you bring up GDB on another SVR4 system, please send mail to
7189 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7191 * Better dynamic linking support in SunOS
7193 Reading symbols from shared libraries which contain debugging symbols
7194 now works properly. However, there remain issues such as automatic
7195 skipping of `transfer vector' code during function calls, which
7196 make it harder to debug code in a shared library, than to debug the
7197 same code linked statically.
7201 GDB is now using the latest `getopt' routines from the FSF. This
7202 version accepts the -- prefix for options with long names. GDB will
7203 continue to accept the old forms (-option and +option) as well.
7204 Various single letter abbreviations for options have been explicity
7205 added to the option table so that they won't get overshadowed in the
7206 future by other options that begin with the same letter.
7210 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7211 Many assorted bugs have been handled. Many more remain to be handled.
7212 See the various ChangeLog files (primarily in gdb and bfd) for details.
7215 *** Changes in GDB-4.3:
7217 * New machines supported (host and target)
7219 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7220 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7221 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7223 * Almost SCO Unix support
7225 We had hoped to support:
7226 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7227 (except for core file support), but we discovered very late in the release
7228 that it has problems with process groups that render gdb unusable. Sorry
7229 about that. I encourage people to fix it and post the fixes.
7231 * Preliminary ELF and DWARF support
7233 GDB can read ELF object files on System V Release 4, and can handle
7234 debugging records for C, in DWARF format, in ELF files. This support
7235 is preliminary. If you bring up GDB on another SVR4 system, please
7236 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7241 GDB now uses the latest `readline' library. One user-visible change
7242 is that two tabs will list possible command completions, which previously
7243 required typing M-? (meta-question mark, or ESC ?).
7247 The `stepi' bug that many of you noticed has been squashed.
7248 Many bugs in C++ have been handled. Many more remain to be handled.
7249 See the various ChangeLog files (primarily in gdb and bfd) for details.
7251 * State of the MIPS world (in case you wondered):
7253 GDB can understand the symbol tables emitted by the compilers
7254 supplied by most vendors of MIPS-based machines, including DEC. These
7255 symbol tables are in a format that essentially nobody else uses.
7257 Some versions of gcc come with an assembler post-processor called
7258 mips-tfile. This program is required if you want to do source-level
7259 debugging of gcc-compiled programs. I believe FSF does not ship
7260 mips-tfile with gcc version 1, but it will eventually come with gcc
7263 Debugging of g++ output remains a problem. g++ version 1.xx does not
7264 really support it at all. (If you're lucky, you should be able to get
7265 line numbers and stack traces to work, but no parameters or local
7266 variables.) With some work it should be possible to improve the
7269 When gcc version 2 is released, you will have somewhat better luck.
7270 However, even then you will get confusing results for inheritance and
7273 We will eventually provide full debugging of g++ output on
7274 DECstations. This will probably involve some kind of stabs-in-ecoff
7275 encapulation, but the details have not been worked out yet.
7278 *** Changes in GDB-4.2:
7280 * Improved configuration
7282 Only one copy of `configure' exists now, and it is not self-modifying.
7283 Porting BFD is simpler.
7287 The `step' and `next' commands now only stop at the first instruction
7288 of a source line. This prevents the multiple stops that used to occur
7289 in switch statements, for-loops, etc. `Step' continues to stop if a
7290 function that has debugging information is called within the line.
7294 Lots of small bugs fixed. More remain.
7296 * New host supported (not target)
7298 Intel 386 PC clone running Mach i386-none-mach
7301 *** Changes in GDB-4.1:
7303 * Multiple source language support
7305 GDB now has internal scaffolding to handle several source languages.
7306 It determines the type of each source file from its filename extension,
7307 and will switch expression parsing and number formatting to match the
7308 language of the function in the currently selected stack frame.
7309 You can also specifically set the language to be used, with
7310 `set language c' or `set language modula-2'.
7314 GDB now has preliminary support for the GNU Modula-2 compiler,
7315 currently under development at the State University of New York at
7316 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7317 continue through the fall of 1991 and into 1992.
7319 Other Modula-2 compilers are currently not supported, and attempting to
7320 debug programs compiled with them will likely result in an error as the
7321 symbol table is read. Feel free to work on it, though!
7323 There are hooks in GDB for strict type checking and range checking,
7324 in the `Modula-2 philosophy', but they do not currently work.
7328 GDB can now write to executable and core files (e.g. patch
7329 a variable's value). You must turn this switch on, specify
7330 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7331 by assigning a new value to a variable. Modifications take
7334 * Automatic SunOS shared library reading
7336 When you run your program, GDB automatically determines where its
7337 shared libraries (if any) have been loaded, and reads their symbols.
7338 The `share' command is no longer needed. This also works when
7339 examining core files.
7343 You can specify the number of lines that the `list' command shows.
7346 * New machines supported (host and target)
7348 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7349 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7350 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7352 * New hosts supported (not targets)
7354 IBM RT/PC: romp-ibm-aix or rtpc
7356 * New targets supported (not hosts)
7358 AMD 29000 embedded with COFF a29k-none-coff
7359 AMD 29000 embedded with a.out a29k-none-aout
7360 Ultracomputer remote kernel debug a29k-nyu-kern
7362 * New remote interfaces
7368 *** Changes in GDB-4.0:
7372 Wide output is wrapped at good places to make the output more readable.
7374 Gdb now supports cross-debugging from a host machine of one type to a
7375 target machine of another type. Communication with the target system
7376 is over serial lines. The ``target'' command handles connecting to the
7377 remote system; the ``load'' command will download a program into the
7378 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7379 also supports debugging of realtime processes running under VxWorks,
7380 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7381 stub on the target system.
7383 New CPUs supported include the AMD 29000 and Intel 960.
7385 GDB now reads object files and symbol tables via a ``binary file''
7386 library, which allows a single copy of GDB to debug programs of multiple
7387 object file types such as a.out and coff.
7389 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7390 refcard.dvi and refcard.ps are available to format it).
7393 * Control-Variable user interface simplified
7395 All variables that control the operation of the debugger can be set
7396 by the ``set'' command, and displayed by the ``show'' command.
7398 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7399 ``Show prompt'' produces the response:
7400 Gdb's prompt is new-gdb=>.
7402 What follows are the NEW set commands. The command ``help set'' will
7403 print a complete list of old and new set commands. ``help set FOO''
7404 will give a longer description of the variable FOO. ``show'' will show
7405 all of the variable descriptions and their current settings.
7407 confirm on/off: Enables warning questions for operations that are
7408 hard to recover from, e.g. rerunning the program while
7409 it is already running. Default is ON.
7411 editing on/off: Enables EMACS style command line editing
7412 of input. Previous lines can be recalled with
7413 control-P, the current line can be edited with control-B,
7414 you can search for commands with control-R, etc.
7417 history filename NAME: NAME is where the gdb command history
7418 will be stored. The default is .gdb_history,
7419 or the value of the environment variable
7422 history size N: The size, in commands, of the command history. The
7423 default is 256, or the value of the environment variable
7426 history save on/off: If this value is set to ON, the history file will
7427 be saved after exiting gdb. If set to OFF, the
7428 file will not be saved. The default is OFF.
7430 history expansion on/off: If this value is set to ON, then csh-like
7431 history expansion will be performed on
7432 command line input. The default is OFF.
7434 radix N: Sets the default radix for input and output. It can be set
7435 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7436 in the current radix, so "set radix 10" is always a no-op.
7438 height N: This integer value is the number of lines on a page. Default
7439 is 24, the current `stty rows'' setting, or the ``li#''
7440 setting from the termcap entry matching the environment
7443 width N: This integer value is the number of characters on a line.
7444 Default is 80, the current `stty cols'' setting, or the ``co#''
7445 setting from the termcap entry matching the environment
7448 Note: ``set screensize'' is obsolete. Use ``set height'' and
7449 ``set width'' instead.
7451 print address on/off: Print memory addresses in various command displays,
7452 such as stack traces and structure values. Gdb looks
7453 more ``symbolic'' if you turn this off; it looks more
7454 ``machine level'' with it on. Default is ON.
7456 print array on/off: Prettyprint arrays. New convenient format! Default
7459 print demangle on/off: Print C++ symbols in "source" form if on,
7462 print asm-demangle on/off: Same, for assembler level printouts
7465 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7468 * Support for Epoch Environment.
7470 The epoch environment is a version of Emacs v18 with windowing. One
7471 new command, ``inspect'', is identical to ``print'', except that if you
7472 are running in the epoch environment, the value is printed in its own
7476 * Support for Shared Libraries
7478 GDB can now debug programs and core files that use SunOS shared libraries.
7479 Symbols from a shared library cannot be referenced
7480 before the shared library has been linked with the program (this
7481 happens after you type ``run'' and before the function main() is entered).
7482 At any time after this linking (including when examining core files
7483 from dynamically linked programs), gdb reads the symbols from each
7484 shared library when you type the ``sharedlibrary'' command.
7485 It can be abbreviated ``share''.
7487 sharedlibrary REGEXP: Load shared object library symbols for files
7488 matching a unix regular expression. No argument
7489 indicates to load symbols for all shared libraries.
7491 info sharedlibrary: Status of loaded shared libraries.
7496 A watchpoint stops execution of a program whenever the value of an
7497 expression changes. Checking for this slows down execution
7498 tremendously whenever you are in the scope of the expression, but is
7499 quite useful for catching tough ``bit-spreader'' or pointer misuse
7500 problems. Some machines such as the 386 have hardware for doing this
7501 more quickly, and future versions of gdb will use this hardware.
7503 watch EXP: Set a watchpoint (breakpoint) for an expression.
7505 info watchpoints: Information about your watchpoints.
7507 delete N: Deletes watchpoint number N (same as breakpoints).
7508 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7509 enable N: Re-enables watchpoint number N (same as breakpoints).
7512 * C++ multiple inheritance
7514 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7517 * C++ exception handling
7519 Gdb now supports limited C++ exception handling. Besides the existing
7520 ability to breakpoint on an exception handler, gdb can breakpoint on
7521 the raising of an exception (before the stack is peeled back to the
7524 catch FOO: If there is a FOO exception handler in the dynamic scope,
7525 set a breakpoint to catch exceptions which may be raised there.
7526 Multiple exceptions (``catch foo bar baz'') may be caught.
7528 info catch: Lists all exceptions which may be caught in the
7529 current stack frame.
7532 * Minor command changes
7534 The command ``call func (arg, arg, ...)'' now acts like the print
7535 command, except it does not print or save a value if the function's result
7536 is void. This is similar to dbx usage.
7538 The ``up'' and ``down'' commands now always print the frame they end up
7539 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7540 frames without printing.
7542 * New directory command
7544 'dir' now adds directories to the FRONT of the source search path.
7545 The path starts off empty. Source files that contain debug information
7546 about the directory in which they were compiled can be found even
7547 with an empty path; Sun CC and GCC include this information. If GDB can't
7548 find your source file in the current directory, type "dir .".
7550 * Configuring GDB for compilation
7552 For normal use, type ``./configure host''. See README or gdb.texinfo
7555 GDB now handles cross debugging. If you are remotely debugging between
7556 two different machines, type ``./configure host -target=targ''.
7557 Host is the machine where GDB will run; targ is the machine
7558 where the program that you are debugging will run.