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 set may-call-functions [on|off]
50 show may-call-functions
51 This controls whether GDB will attempt to call functions in
52 the program, such as with expressions in the print command. It
53 defaults to on. Calling functions in the program being debugged
54 can have undesired side effects. It is now possible to forbid
55 such function calls. If function calls are forbidden, GDB will throw
56 an error when a command (such as print expression) calls a function
59 set print finish [on|off]
61 This controls whether the `finish' command will display the value
62 that is returned by the current function. When `off', the value is
63 still entered into the value history, but it is not printed. The
68 Allows deeply nested structures to be simplified when printing by
69 replacing deeply nested parts (beyond the max-depth) with ellipses.
70 The default max-depth is 20, but this can be set to unlimited to get
71 the old behavior back.
73 set logging debugredirect [on|off]
74 By default, GDB debug output will go to both the terminal and the logfile.
75 Set if you want debug output to go only to the log file.
77 set style title foreground COLOR
78 set style title background COLOR
79 set style title intensity VALUE
80 Control the styling of titles.
82 set style highlight foreground COLOR
83 set style highlight background COLOR
84 set style highlight intensity VALUE
85 Control the styling of highlightings.
87 maint test-settings KIND
88 A set of commands used by the testsuite for exercising the settings
94 The "help" command uses the title style to enhance the
95 readibility of its output by styling the classes and
99 Similarly to "help", the "apropos" command also uses the
100 title style for the command names. "apropos" accepts now
101 a flag "-v" (verbose) to show the full documentation
102 of matching commands and to use the highlight style to mark
103 the documentation parts matching REGEXP.
106 The "show style" and its subcommands are now styling
107 a style name in their output using its own style, to help
108 the user visualize the different styles.
110 set print raw-frame-arguments
111 show print raw-frame-arguments
113 These commands replace the similarly-named "set/show print raw
114 frame-arguments" commands (now with a dash instead of a space). The
115 old commands are now deprecated and may be removed in a future
118 maint test-options require-delimiter
119 maint test-options unknown-is-error
120 maint test-options unknown-is-operand
121 maint show test-options-completion-result
122 Commands used by the testsuite to validate the command options
125 * New command options, command completion
127 GDB now has a standard infrastructure to support dash-style command
128 options ('-OPT'). One benefit is that commands that use it can
129 easily support completion of command line arguments. Try "CMD
130 -[TAB]" or "help CMD" to find options supported by a command. Over
131 time, we intend to migrate most commands to this infrastructure. A
132 number of commands got support for new command options in this
135 ** The "print" and "compile print" commands now support a number of
136 options that allow overriding relevant global print settings as
137 set by "set print" subcommands:
141 -array-indexes [on|off]
142 -elements NUMBER|unlimited
146 -repeats NUMBER|unlimited
147 -static-members [on|off]
152 Note that because the "print"/"compile print" commands accept
153 arbitrary expressions which may look like options (including
154 abbreviations), if you specify any command option, then you must
155 use a double dash ("--") to mark the end of argument processing.
157 ** The "backtrace" command now supports a number of options that
158 allow overriding relevant global print settings as set by "set
159 backtrace" and "set print" subcommands:
161 -entry-values no|only|preferred|if-needed|both|compact|default
162 -frame-arguments all|scalars|none
163 -raw-frame-arguments [on|off]
167 In addition, the full/no-filters/hide qualifiers are now also
168 exposed as command options too:
174 ** The "frame apply", "tfaas" and "faas" commands similarly now
175 support the following options:
180 All options above can also be abbreviated. The argument of boolean
181 (on/off) options can be 0/1 too, and also the argument is assumed
182 "on" if omitted. This allows writing compact command invocations,
185 (gdb) p -r -p -o 0 -- *myptr
187 The above is equivalent to:
189 (gdb) print -raw -pretty -object off -- *myptr
191 * Completion improvements
193 ** GDB can now complete the options of the "thread apply all" and
194 "taas" commands, and their "-ascending" option can now be
197 ** GDB can now complete the options of the "compile file" and
198 "compile code" commands. The "compile file" command now
199 completes on filenames.
201 ** GDB can now complete the backtrace command's
202 "full/no-filters/hide" qualifiers.
204 * In settings, you can now abbreviate "unlimited".
206 E.g., "set print elements u" is now equivalent to "set print
212 This lists all the possible completions for the rest of the line, if it
213 were to be given as a command itself. This is intended for use by MI
214 frontends in cases when separate CLI and MI channels cannot be used.
216 -catch-throw, -catch-rethrow, and -catch-catch
217 These can be used to catch C++ exceptions in a similar fashion to
218 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
222 The testsuite now creates the files gdb.cmd (containing the arguments
223 used to launch GDB) and gdb.in (containing all the commands sent to
224 GDB) in the output directory for each test script. Multiple invocations
225 are appended with .1, .2, .3 etc.
227 *** Changes in GDB 8.3
229 * GDB and GDBserver now support access to additional registers on
230 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
233 * GDB now has experimental support for the compilation and injection of
234 C++ source code into the inferior. This beta release does not include
235 support for several language features, such as templates, constructors,
238 This feature requires GCC 7.1 or higher built with libcp1.so
241 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
242 can be passed using the '[ADDRESS]:PORT' notation, or the regular
243 'ADDRESS:PORT' method.
245 * DWARF index cache: GDB can now automatically save indices of DWARF
246 symbols on disk to speed up further loading of the same binaries.
248 * Ada task switching is now supported on aarch64-elf targets when
249 debugging a program using the Ravenscar Profile. For more information,
250 see the "Tasking Support when using the Ravenscar Profile" section
251 in the GDB user manual.
253 * GDB in batch mode now exits with status 1 if the last command to be
256 * The RISC-V target now supports target descriptions.
258 * System call catchpoints now support system call aliases on FreeBSD.
259 When the ABI of a system call changes in FreeBSD, this is
260 implemented by leaving a compatibility system call using the old ABI
261 at the existing number and allocating a new system call number for
262 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
263 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
264 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
265 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
266 so that a system call catchpoint for the 'kevent' system call will
267 catch invocations of both the 'kevent' and 'freebsd11_kevent'
268 binaries. This ensures that 'kevent' system calls are caught for
269 binaries using either the old or new ABIs.
271 * Terminal styling is now available for the CLI and the TUI. GNU
272 Source Highlight can additionally be used to provide styling of
273 source code snippets. See the "set style" commands, below, for more
276 * Removed support for old demangling styles arm, edg, gnu, hp and
281 set debug compile-cplus-types
282 show debug compile-cplus-types
283 Control the display of debug output about type conversion in the
284 C++ compile feature. Commands have no effect while compiliong
289 Control whether debug output about files/functions skipping is
292 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
293 Apply a command to some frames.
294 FLAG arguments allow to control what output to produce and how to handle
295 errors raised when applying COMMAND to a frame.
298 Apply a command to all threads (ignoring errors and empty output).
299 Shortcut for 'thread apply all -s COMMAND'.
302 Apply a command to all frames (ignoring errors and empty output).
303 Shortcut for 'frame apply all -s COMMAND'.
306 Apply a command to all frames of all threads (ignoring errors and empty
308 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
310 maint set dwarf unwinders (on|off)
311 maint show dwarf unwinders
312 Control whether DWARF unwinders can be used.
315 Display a list of open files for a process.
319 Changes to the "frame", "select-frame", and "info frame" CLI commands.
320 These commands all now take a frame specification which
321 is either a frame level, or one of the keywords 'level', 'address',
322 'function', or 'view' followed by a parameter. Selecting a frame by
323 address, or viewing a frame outside the current backtrace now
324 requires the use of a keyword. Selecting a frame by level is
325 unchanged. The MI comment "-stack-select-frame" is unchanged.
327 target remote FILENAME
328 target extended-remote FILENAME
329 If FILENAME is a Unix domain socket, GDB will attempt to connect
330 to this socket instead of opening FILENAME as a character device.
332 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
333 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
334 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
335 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
336 These commands can now print only the searched entities
337 matching the provided regexp(s), giving a condition
338 on the entity names or entity types. The flag -q disables
339 printing headers or informations messages.
345 These commands now determine the syntax for the shown entities
346 according to the language chosen by `set language'. In particular,
347 `set language auto' means to automatically choose the language of
350 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
351 The 'thread apply' command accepts new FLAG arguments.
352 FLAG arguments allow to control what output to produce and how to handle
353 errors raised when applying COMMAND to a thread.
355 set tui tab-width NCHARS
356 show tui tab-width NCHARS
357 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
359 set style enabled [on|off]
361 Enable or disable terminal styling. Styling is enabled by default
362 on most hosts, but disabled by default when in batch mode.
364 set style sources [on|off]
366 Enable or disable source code styling. Source code styling is
367 enabled by default, but only takes effect if styling in general is
368 enabled, and if GDB was linked with GNU Source Highlight.
370 set style filename foreground COLOR
371 set style filename background COLOR
372 set style filename intensity VALUE
373 Control the styling of file names.
375 set style function foreground COLOR
376 set style function background COLOR
377 set style function intensity VALUE
378 Control the styling of function names.
380 set style variable foreground COLOR
381 set style variable background COLOR
382 set style variable intensity VALUE
383 Control the styling of variable names.
385 set style address foreground COLOR
386 set style address background COLOR
387 set style address intensity VALUE
388 Control the styling of addresses.
392 ** The default version of the MI interpreter is now 3 (-i=mi3).
394 ** The '-data-disassemble' MI command now accepts an '-a' option to
395 disassemble the whole function surrounding the given program
396 counter value or function name. Support for this feature can be
397 verified by using the "-list-features" command, which should
398 contain "data-disassemble-a-option".
400 ** Command responses and notifications that include a frame now include
401 the frame's architecture in a new "arch" attribute.
403 ** The output of information about multi-location breakpoints (which is
404 syntactically incorrect in MI 2) has changed in MI 3. This affects
405 the following commands and events:
409 - =breakpoint-created
410 - =breakpoint-modified
412 The -fix-multi-location-breakpoint-output command can be used to enable
413 this behavior with previous MI versions.
415 * New native configurations
417 GNU/Linux/RISC-V riscv*-*-linux*
418 FreeBSD/riscv riscv*-*-freebsd*
422 GNU/Linux/RISC-V riscv*-*-linux*
424 CSKY GNU/LINUX csky*-*-linux
425 FreeBSD/riscv riscv*-*-freebsd*
427 GNU/Linux/OpenRISC or1k*-*-linux*
431 GDB no longer supports native debugging on versions of MS-Windows
436 ** GDB no longer supports Python versions less than 2.6.
438 ** The gdb.Inferior type has a new 'progspace' property, which is the program
439 space associated to that inferior.
441 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
442 of objfiles associated to that program space.
444 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
445 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
448 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
449 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
450 correct and did not work properly.
452 ** The gdb.Value type has a new constructor, which is used to construct a
453 gdb.Value from a Python buffer object and a gdb.Type.
459 Enable or disable the undefined behavior sanitizer. This is
460 disabled by default, but passing --enable-ubsan=yes or
461 --enable-ubsan=auto to configure will enable it. Enabling this can
462 cause a performance penalty. The undefined behavior sanitizer was
463 first introduced in GCC 4.9.
465 *** Changes in GDB 8.2
467 * The 'set disassembler-options' command now supports specifying options
470 * The 'symbol-file' command now accepts an '-o' option to add a relative
471 offset to all sections.
473 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
474 a relative offset to all sections, but it allows to override the load
475 address of individual sections using '-s'.
477 * The 'add-symbol-file' command no longer requires the second argument
478 (address of the text section).
480 * The endianness used with the 'set endian auto' mode in the absence of
481 an executable selected for debugging is now the last endianness chosen
482 either by one of the 'set endian big' and 'set endian little' commands
483 or by inferring from the last executable used, rather than the startup
486 * The pager now allows a "c" response, meaning to disable the pager
487 for the rest of the current command.
489 * The commands 'info variables/functions/types' now show the source line
490 numbers of symbol definitions when available.
492 * 'info proc' now works on running processes on FreeBSD systems and core
493 files created on FreeBSD systems.
495 * C expressions can now use _Alignof, and C++ expressions can now use
498 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
499 the vector length while the process is running.
505 Control display of debugging info regarding the FreeBSD native target.
507 set|show varsize-limit
508 This new setting allows the user to control the maximum size of Ada
509 objects being printed when those objects have a variable type,
510 instead of that maximum size being hardcoded to 65536 bytes.
512 set|show record btrace cpu
513 Controls the processor to be used for enabling errata workarounds for
516 maint check libthread-db
517 Run integrity checks on the current inferior's thread debugging
520 maint set check-libthread-db (on|off)
521 maint show check-libthread-db
522 Control whether to run integrity checks on inferior specific thread
523 debugging libraries as they are loaded. The default is not to
528 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
530 ** The commands attached to a breakpoint can be set by assigning to
531 the breakpoint's "commands" field.
533 ** gdb.execute can now execute multi-line gdb commands.
535 ** The new functions gdb.convenience_variable and
536 gdb.set_convenience_variable can be used to get and set the value
537 of convenience variables.
539 ** A gdb.Parameter will no longer print the "set" help text on an
540 ordinary "set"; instead by default a "set" will be silent unless
541 the get_set_string method returns a non-empty string.
545 RiscV ELF riscv*-*-elf
547 * Removed targets and native configurations
549 m88k running OpenBSD m88*-*-openbsd*
550 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
551 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
552 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
554 * Aarch64/Linux hardware watchpoints improvements
556 Hardware watchpoints on unaligned addresses are now properly
557 supported when running Linux kernel 4.10 or higher: read and access
558 watchpoints are no longer spuriously missed, and all watchpoints
559 lengths between 1 and 8 bytes are supported. On older kernels,
560 watchpoints set on unaligned addresses are no longer missed, with
561 the tradeoff that there is a possibility of false hits being
566 --enable-codesign=CERT
567 This can be used to invoke "codesign -s CERT" after building gdb.
568 This option is useful on macOS, where code signing is required for
569 gdb to work properly.
571 --disable-gdbcli has been removed
572 This is now silently accepted, but does nothing.
574 *** Changes in GDB 8.1
576 * GDB now supports dynamically creating arbitrary register groups specified
577 in XML target descriptions. This allows for finer grain grouping of
578 registers on systems with a large amount of registers.
580 * The 'ptype' command now accepts a '/o' flag, which prints the
581 offsets and sizes of fields in a struct, like the pahole(1) tool.
583 * New "--readnever" command line option instructs GDB to not read each
584 symbol file's symbolic debug information. This makes startup faster
585 but at the expense of not being able to perform symbolic debugging.
586 This option is intended for use cases where symbolic debugging will
587 not be used, e.g., when you only need to dump the debuggee's core.
589 * GDB now uses the GNU MPFR library, if available, to emulate target
590 floating-point arithmetic during expression evaluation when the target
591 uses different floating-point formats than the host. At least version
592 3.1 of GNU MPFR is required.
594 * GDB now supports access to the guarded-storage-control registers and the
595 software-based guarded-storage broadcast control registers on IBM z14.
597 * On Unix systems, GDB now supports transmitting environment variables
598 that are to be set or unset to GDBserver. These variables will
599 affect the environment to be passed to the remote inferior.
601 To inform GDB of environment variables that are to be transmitted to
602 GDBserver, use the "set environment" command. Only user set
603 environment variables are sent to GDBserver.
605 To inform GDB of environment variables that are to be unset before
606 the remote inferior is started by the GDBserver, use the "unset
607 environment" command.
609 * Completion improvements
611 ** GDB can now complete function parameters in linespecs and
612 explicit locations without quoting. When setting breakpoints,
613 quoting around functions names to help with TAB-completion is
614 generally no longer necessary. For example, this now completes
617 (gdb) b function(in[TAB]
618 (gdb) b function(int)
620 Related, GDB is no longer confused with completing functions in
621 C++ anonymous namespaces:
624 (gdb) b (anonymous namespace)::[TAB][TAB]
625 (anonymous namespace)::a_function()
626 (anonymous namespace)::b_function()
628 ** GDB now has much improved linespec and explicit locations TAB
629 completion support, that better understands what you're
630 completing and offers better suggestions. For example, GDB no
631 longer offers data symbols as possible completions when you're
632 setting a breakpoint.
634 ** GDB now TAB-completes label symbol names.
636 ** The "complete" command now mimics TAB completion accurately.
638 * New command line options (gcore)
641 Dump all memory mappings.
643 * Breakpoints on C++ functions are now set on all scopes by default
645 By default, breakpoints on functions/methods are now interpreted as
646 specifying all functions with the given name ignoring missing
647 leading scopes (namespaces and classes).
649 For example, assuming a C++ program with symbols named:
654 both commands "break func()" and "break B::func()" set a breakpoint
657 You can use the new flag "-qualified" to override this. This makes
658 GDB interpret the specified function name as a complete
659 fully-qualified name instead. For example, using the same C++
660 program, the "break -q B::func" command sets a breakpoint on
661 "B::func", only. A parameter has been added to the Python
662 gdb.Breakpoint constructor to achieve the same result when creating
663 a breakpoint from Python.
665 * Breakpoints on functions marked with C++ ABI tags
667 GDB can now set breakpoints on functions marked with C++ ABI tags
668 (e.g., [abi:cxx11]). See here for a description of ABI tags:
669 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
671 Functions with a C++11 abi tag are demangled/displayed like this:
673 function[abi:cxx11](int)
676 You can now set a breakpoint on such functions simply as if they had
679 (gdb) b function(int)
681 Or if you need to disambiguate between tags, like:
683 (gdb) b function[abi:other_tag](int)
685 Tab completion was adjusted accordingly as well.
689 ** New events gdb.new_inferior, gdb.inferior_deleted, and
690 gdb.new_thread are emitted. See the manual for further
691 description of these.
693 ** A new function, "gdb.rbreak" has been added to the Python API.
694 This function allows the setting of a large number of breakpoints
695 via a regex pattern in Python. See the manual for further details.
697 ** Python breakpoints can now accept explicit locations. See the
698 manual for a further description of this feature.
701 * New features in the GDB remote stub, GDBserver
703 ** GDBserver is now able to start inferior processes with a
704 specified initial working directory.
706 The user can set the desired working directory to be used from
707 GDB using the new "set cwd" command.
709 ** New "--selftest" command line option runs some GDBserver self
710 tests. These self tests are disabled in releases.
712 ** On Unix systems, GDBserver now does globbing expansion and variable
713 substitution in inferior command line arguments.
715 This is done by starting inferiors using a shell, like GDB does.
716 See "set startup-with-shell" in the user manual for how to disable
717 this from GDB when using "target extended-remote". When using
718 "target remote", you can disable the startup with shell by using the
719 new "--no-startup-with-shell" GDBserver command line option.
721 ** On Unix systems, GDBserver now supports receiving environment
722 variables that are to be set or unset from GDB. These variables
723 will affect the environment to be passed to the inferior.
725 * When catching an Ada exception raised with a message, GDB now prints
726 the message in the catchpoint hit notification. In GDB/MI mode, that
727 information is provided as an extra field named "exception-message"
728 in the *stopped notification.
730 * Trait objects can now be inspected When debugging Rust code. This
731 requires compiler support which will appear in Rust 1.24.
735 QEnvironmentHexEncoded
736 Inform GDBserver of an environment variable that is to be passed to
737 the inferior when starting it.
740 Inform GDBserver of an environment variable that is to be unset
741 before starting the remote inferior.
744 Inform GDBserver that the environment should be reset (i.e.,
745 user-set environment variables should be unset).
748 Indicates whether the inferior must be started with a shell or not.
751 Tell GDBserver that the inferior to be started should use a specific
754 * The "maintenance print c-tdesc" command now takes an optional
755 argument which is the file name of XML target description.
757 * The "maintenance selftest" command now takes an optional argument to
758 filter the tests to be run.
760 * The "enable", and "disable" commands now accept a range of
761 breakpoint locations, e.g. "enable 1.3-5".
766 Set and show the current working directory for the inferior.
769 Set and show compilation command used for compiling and injecting code
770 with the 'compile' commands.
772 set debug separate-debug-file
773 show debug separate-debug-file
774 Control the display of debug output about separate debug file search.
776 set dump-excluded-mappings
777 show dump-excluded-mappings
778 Control whether mappings marked with the VM_DONTDUMP flag should be
779 dumped when generating a core file.
782 List the registered selftests.
785 Start the debugged program stopping at the first instruction.
788 Control display of debugging messages related to OpenRISC targets.
790 set|show print type nested-type-limit
791 Set and show the limit of nesting level for nested types that the
792 type printer will show.
794 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
797 * Safer/improved support for debugging with no debug info
799 GDB no longer assumes functions with no debug information return
802 This means that GDB now refuses to call such functions unless you
803 tell it the function's type, by either casting the call to the
804 declared return type, or by casting the function to a function
805 pointer of the right type, and calling that:
807 (gdb) p getenv ("PATH")
808 'getenv' has unknown return type; cast the call to its declared return type
809 (gdb) p (char *) getenv ("PATH")
810 $1 = 0x7fffffffe "/usr/local/bin:/"...
811 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
812 $2 = 0x7fffffffe "/usr/local/bin:/"...
814 Similarly, GDB no longer assumes that global variables with no debug
815 info have type 'int', and refuses to print the variable's value
816 unless you tell it the variable's type:
819 'var' has unknown type; cast it to its declared type
823 * New native configurations
825 FreeBSD/aarch64 aarch64*-*-freebsd*
826 FreeBSD/arm arm*-*-freebsd*
830 FreeBSD/aarch64 aarch64*-*-freebsd*
831 FreeBSD/arm arm*-*-freebsd*
832 OpenRISC ELF or1k*-*-elf
834 * Removed targets and native configurations
836 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
838 *** Changes in GDB 8.0
840 * GDB now supports access to the PKU register on GNU/Linux. The register is
841 added by the Memory Protection Keys for Userspace feature which will be
842 available in future Intel CPUs.
844 * GDB now supports C++11 rvalue references.
848 ** New functions to start, stop and access a running btrace recording.
849 ** Rvalue references are now supported in gdb.Type.
851 * GDB now supports recording and replaying rdrand and rdseed Intel 64
854 * Building GDB and GDBserver now requires a C++11 compiler.
856 For example, GCC 4.8 or later.
858 It is no longer possible to build GDB or GDBserver with a C
859 compiler. The --disable-build-with-cxx configure option has been
862 * Building GDB and GDBserver now requires GNU make >= 3.81.
864 It is no longer supported to build GDB or GDBserver with another
865 implementation of the make program or an earlier version of GNU make.
867 * Native debugging on MS-Windows supports command-line redirection
869 Command-line arguments used for starting programs on MS-Windows can
870 now include redirection symbols supported by native Windows shells,
871 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
872 as "run", "start", and "set args", as well as the corresponding MI
875 * Support for thread names on MS-Windows.
877 GDB now catches and handles the special exception that programs
878 running on MS-Windows use to assign names to threads in the
881 * Support for Java programs compiled with gcj has been removed.
883 * User commands now accept an unlimited number of arguments.
884 Previously, only up to 10 was accepted.
886 * The "eval" command now expands user-defined command arguments.
888 This makes it easier to process a variable number of arguments:
893 eval "print $arg%d", $i
898 * Target descriptions can now describe registers for sparc32 and sparc64.
900 * GDB now supports DWARF version 5 (debug information format).
901 Its .debug_names index is not yet supported.
903 * New native configurations
905 FreeBSD/mips mips*-*-freebsd
909 Synopsys ARC arc*-*-elf32
910 FreeBSD/mips mips*-*-freebsd
912 * Removed targets and native configurations
914 Alpha running FreeBSD alpha*-*-freebsd*
915 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
920 Erases all the flash memory regions reported by the target.
922 maint print arc arc-instruction address
923 Print internal disassembler information about instruction at a given address.
927 set disassembler-options
928 show disassembler-options
929 Controls the passing of target specific information to the disassembler.
930 If it is necessary to specify more than one disassembler option then
931 multiple options can be placed together into a comma separated list.
932 The default value is the empty string. Currently, the only supported
933 targets are ARM, PowerPC and S/390.
938 Erases all the flash memory regions reported by the target. This is
939 equivalent to the CLI command flash-erase.
941 -file-list-shared-libraries
942 List the shared libraries in the program. This is
943 equivalent to the CLI command "info shared".
946 Catchpoints stopping the program when Ada exceptions are
947 handled. This is equivalent to the CLI command "catch handlers".
949 *** Changes in GDB 7.12
951 * GDB and GDBserver now build with a C++ compiler by default.
953 The --enable-build-with-cxx configure option is now enabled by
954 default. One must now explicitly configure with
955 --disable-build-with-cxx in order to build with a C compiler. This
956 option will be removed in a future release.
958 * GDBserver now supports recording btrace without maintaining an active
961 * GDB now supports a negative repeat count in the 'x' command to examine
962 memory backward from the given address. For example:
965 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
966 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
967 (gdb) x/-5i 0x0000000000400580
968 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
969 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
970 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
971 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
972 0x40057b <main(int, char**)+25>:
973 callq 0x400536 <Func1(int, char const*)>
975 * Fortran: Support structures with fields of dynamic types and
976 arrays of dynamic types.
978 * The symbol dumping maintenance commands have new syntax.
979 maint print symbols [-pc address] [--] [filename]
980 maint print symbols [-objfile objfile] [-source source] [--] [filename]
981 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
982 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
983 maint print msymbols [-objfile objfile] [--] [filename]
985 * GDB now supports multibit bitfields and enums in target register
988 * New Python-based convenience function $_as_string(val), which returns
989 the textual representation of a value. This function is especially
990 useful to obtain the text label of an enum value.
992 * Intel MPX bound violation handling.
994 Segmentation faults caused by a Intel MPX boundary violation
995 now display the kind of violation (upper or lower), the memory
996 address accessed and the memory bounds, along with the usual
997 signal received and code location.
1001 Program received signal SIGSEGV, Segmentation fault
1002 Upper bound violation while accessing address 0x7fffffffc3b3
1003 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1004 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1006 * Rust language support.
1007 GDB now supports debugging programs written in the Rust programming
1008 language. See https://www.rust-lang.org/ for more information about
1011 * Support for running interpreters on specified input/output devices
1013 GDB now supports a new mechanism that allows frontends to provide
1014 fully featured GDB console views, as a better alternative to
1015 building such views on top of the "-interpreter-exec console"
1016 command. See the new "new-ui" command below. With that command,
1017 frontends can now start GDB in the traditional command-line mode
1018 running in an embedded terminal emulator widget, and create a
1019 separate MI interpreter running on a specified i/o device. In this
1020 way, GDB handles line editing, history, tab completion, etc. in the
1021 console all by itself, and the GUI uses the separate MI interpreter
1022 for its own control and synchronization, invisible to the command
1025 * The "catch syscall" command catches groups of related syscalls.
1027 The "catch syscall" command now supports catching a group of related
1028 syscalls using the 'group:' or 'g:' prefix.
1033 skip -gfile file-glob-pattern
1034 skip -function function
1035 skip -rfunction regular-expression
1036 A generalized form of the skip command, with new support for
1037 glob-style file names and regular expressions for function names.
1038 Additionally, a file spec and a function spec may now be combined.
1040 maint info line-table REGEXP
1041 Display the contents of GDB's internal line table data struture.
1044 Run any GDB unit tests that were compiled in.
1047 Start a new user interface instance running INTERP as interpreter,
1048 using the TTY file for input/output.
1052 ** gdb.Breakpoint objects have a new attribute "pending", which
1053 indicates whether the breakpoint is pending.
1054 ** Three new breakpoint-related events have been added:
1055 gdb.breakpoint_created, gdb.breakpoint_modified, and
1056 gdb.breakpoint_deleted.
1058 signal-event EVENTID
1059 Signal ("set") the given MS-Windows event object. This is used in
1060 conjunction with the Windows JIT debugging (AeDebug) support, where
1061 the OS suspends a crashing process until a debugger can attach to
1062 it. Resuming the crashing process, in order to debug it, is done by
1063 signalling an event.
1065 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1066 was added in GDBserver, including JIT compiling fast tracepoint's
1067 conditional expression bytecode into native code.
1069 * Support for various remote target protocols and ROM monitors has
1072 target m32rsdi Remote M32R debugging over SDI
1073 target mips MIPS remote debugging protocol
1074 target pmon PMON ROM monitor
1075 target ddb NEC's DDB variant of PMON for Vr4300
1076 target rockhopper NEC RockHopper variant of PMON
1077 target lsi LSI variant of PMO
1079 * Support for tracepoints and fast tracepoints on powerpc-linux,
1080 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1081 including JIT compiling fast tracepoint's conditional expression
1082 bytecode into native code.
1084 * MI async record =record-started now includes the method and format used for
1085 recording. For example:
1087 =record-started,thread-group="i1",method="btrace",format="bts"
1089 * MI async record =thread-selected now includes the frame field. For example:
1091 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1095 Andes NDS32 nds32*-*-elf
1097 *** Changes in GDB 7.11
1099 * GDB now supports debugging kernel-based threads on FreeBSD.
1101 * Per-inferior thread numbers
1103 Thread numbers are now per inferior instead of global. If you're
1104 debugging multiple inferiors, GDB displays thread IDs using a
1105 qualified INF_NUM.THR_NUM form. For example:
1109 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1110 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1111 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1112 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1114 As consequence, thread numbers as visible in the $_thread
1115 convenience variable and in Python's InferiorThread.num attribute
1116 are no longer unique between inferiors.
1118 GDB now maintains a second thread ID per thread, referred to as the
1119 global thread ID, which is the new equivalent of thread numbers in
1120 previous releases. See also $_gthread below.
1122 For backwards compatibility, MI's thread IDs always refer to global
1125 * Commands that accept thread IDs now accept the qualified
1126 INF_NUM.THR_NUM form as well. For example:
1129 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1132 * In commands that accept a list of thread IDs, you can now refer to
1133 all threads of an inferior using a star wildcard. GDB accepts
1134 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1135 refer to all threads of the current inferior. For example, "info
1138 * You can use "info threads -gid" to display the global thread ID of
1141 * The new convenience variable $_gthread holds the global number of
1144 * The new convenience variable $_inferior holds the number of the
1147 * GDB now displays the ID and name of the thread that hit a breakpoint
1148 or received a signal, if your program is multi-threaded. For
1151 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1152 Thread 1 "main" received signal SIGINT, Interrupt.
1154 * Record btrace now supports non-stop mode.
1156 * Support for tracepoints on aarch64-linux was added in GDBserver.
1158 * The 'record instruction-history' command now indicates speculative execution
1159 when using the Intel Processor Trace recording format.
1161 * GDB now allows users to specify explicit locations, bypassing
1162 the linespec parser. This feature is also available to GDB/MI
1165 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1166 GDB now is able to debug both AArch64 applications and ARM applications
1169 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1170 including JIT compiling fast tracepoint's conditional expression bytecode
1173 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1175 * "info threads", "info inferiors", "info display", "info checkpoints"
1176 and "maint info program-spaces" now list the corresponding items in
1177 ascending ID order, for consistency with all other "info" commands.
1179 * In Ada, the overloads selection menu has been enhanced to display the
1180 parameter types and the return types for the matching overloaded subprograms.
1184 maint set target-non-stop (on|off|auto)
1185 maint show target-non-stop
1186 Control whether GDB targets always operate in non-stop mode even if
1187 "set non-stop" is "off". The default is "auto", meaning non-stop
1188 mode is enabled if supported by the target.
1190 maint set bfd-sharing
1191 maint show bfd-sharing
1192 Control the reuse of bfd objects.
1195 show debug bfd-cache
1196 Control display of debugging info regarding bfd caching.
1200 Control display of debugging info regarding FreeBSD threads.
1202 set remote multiprocess-extensions-packet
1203 show remote multiprocess-extensions-packet
1204 Set/show the use of the remote protocol multiprocess extensions.
1206 set remote thread-events
1207 show remote thread-events
1208 Set/show the use of thread create/exit events.
1210 set ada print-signatures on|off
1211 show ada print-signatures"
1212 Control whether parameter types and return types are displayed in overloads
1213 selection menus. It is activaled (@code{on}) by default.
1217 Controls the maximum size of memory, in bytes, that GDB will
1218 allocate for value contents. Prevents incorrect programs from
1219 causing GDB to allocate overly large buffers. Default is 64k.
1221 * The "disassemble" command accepts a new modifier: /s.
1222 It prints mixed source+disassembly like /m with two differences:
1223 - disassembled instructions are now printed in program order, and
1224 - and source for all relevant files is now printed.
1225 The "/m" option is now considered deprecated: its "source-centric"
1226 output hasn't proved useful in practice.
1228 * The "record instruction-history" command accepts a new modifier: /s.
1229 It behaves exactly like /m and prints mixed source+disassembly.
1231 * The "set scheduler-locking" command supports a new mode "replay".
1232 It behaves like "off" in record mode and like "on" in replay mode.
1234 * Support for various ROM monitors has been removed:
1236 target dbug dBUG ROM monitor for Motorola ColdFire
1237 target picobug Motorola picobug monitor
1238 target dink32 DINK32 ROM monitor for PowerPC
1239 target m32r Renesas M32R/D ROM monitor
1240 target mon2000 mon2000 ROM monitor
1241 target ppcbug PPCBUG ROM monitor for PowerPC
1243 * Support for reading/writing memory and extracting values on architectures
1244 whose memory is addressable in units of any integral multiple of 8 bits.
1247 Allows to break when an Ada exception is handled.
1249 * New remote packets
1252 Indicates that an exec system call was executed.
1254 exec-events feature in qSupported
1255 The qSupported packet allows GDB to request support for exec
1256 events using the new 'gdbfeature' exec-event, and the qSupported
1257 response can contain the corresponding 'stubfeature'. Set and
1258 show commands can be used to display whether these features are enabled.
1261 Equivalent to interrupting with the ^C character, but works in
1264 thread created stop reason (T05 create:...)
1265 Indicates that the thread was just created and is stopped at entry.
1267 thread exit stop reply (w exitcode;tid)
1268 Indicates that the thread has terminated.
1271 Enables/disables thread create and exit event reporting. For
1272 example, this is used in non-stop mode when GDB stops a set of
1273 threads and synchronously waits for the their corresponding stop
1274 replies. Without exit events, if one of the threads exits, GDB
1275 would hang forever not knowing that it should no longer expect a
1276 stop for that same thread.
1279 Indicates that there are no resumed threads left in the target (all
1280 threads are stopped). The remote stub reports support for this stop
1281 reply to GDB's qSupported query.
1284 Enables/disables catching syscalls from the inferior process.
1285 The remote stub reports support for this packet to GDB's qSupported query.
1287 syscall_entry stop reason
1288 Indicates that a syscall was just called.
1290 syscall_return stop reason
1291 Indicates that a syscall just returned.
1293 * Extended-remote exec events
1295 ** GDB now has support for exec events on extended-remote Linux targets.
1296 For such targets with Linux kernels 2.5.46 and later, this enables
1297 follow-exec-mode and exec catchpoints.
1299 set remote exec-event-feature-packet
1300 show remote exec-event-feature-packet
1301 Set/show the use of the remote exec event feature.
1303 * Thread names in remote protocol
1305 The reply to qXfer:threads:read may now include a name attribute for each
1308 * Target remote mode fork and exec events
1310 ** GDB now has support for fork and exec events on target remote mode
1311 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1312 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1313 fork and exec catchpoints.
1315 * Remote syscall events
1317 ** GDB now has support for catch syscall on remote Linux targets,
1318 currently enabled on x86/x86_64 architectures.
1320 set remote catch-syscall-packet
1321 show remote catch-syscall-packet
1322 Set/show the use of the remote catch syscall feature.
1326 ** The -var-set-format command now accepts the zero-hexadecimal
1327 format. It outputs data in hexadecimal format with zero-padding on the
1332 ** gdb.InferiorThread objects have a new attribute "global_num",
1333 which refers to the thread's global thread ID. The existing
1334 "num" attribute now refers to the thread's per-inferior number.
1335 See "Per-inferior thread numbers" above.
1336 ** gdb.InferiorThread objects have a new attribute "inferior", which
1337 is the Inferior object the thread belongs to.
1339 *** Changes in GDB 7.10
1341 * Support for process record-replay and reverse debugging on aarch64*-linux*
1342 targets has been added. GDB now supports recording of A64 instruction set
1343 including advance SIMD instructions.
1345 * Support for Sun's version of the "stabs" debug file format has been removed.
1347 * GDB now honors the content of the file /proc/PID/coredump_filter
1348 (PID is the process ID) on GNU/Linux systems. This file can be used
1349 to specify the types of memory mappings that will be included in a
1350 corefile. For more information, please refer to the manual page of
1351 "core(5)". GDB also has a new command: "set use-coredump-filter
1352 on|off". It allows to set whether GDB will read the content of the
1353 /proc/PID/coredump_filter file when generating a corefile.
1355 * The "info os" command on GNU/Linux can now display information on
1357 "info os cpus" Listing of all cpus/cores on the system
1359 * GDB has two new commands: "set serial parity odd|even|none" and
1360 "show serial parity". These allows to set or show parity for the
1363 * The "info source" command now displays the producer string if it was
1364 present in the debug info. This typically includes the compiler version
1365 and may include things like its command line arguments.
1367 * The "info dll", an alias of the "info sharedlibrary" command,
1368 is now available on all platforms.
1370 * Directory names supplied to the "set sysroot" commands may be
1371 prefixed with "target:" to tell GDB to access shared libraries from
1372 the target system, be it local or remote. This replaces the prefix
1373 "remote:". The default sysroot has been changed from "" to
1374 "target:". "remote:" is automatically converted to "target:" for
1375 backward compatibility.
1377 * The system root specified by "set sysroot" will be prepended to the
1378 filename of the main executable (if reported to GDB as absolute by
1379 the operating system) when starting processes remotely, and when
1380 attaching to already-running local or remote processes.
1382 * GDB now supports automatic location and retrieval of executable
1383 files from remote targets. Remote debugging can now be initiated
1384 using only a "target remote" or "target extended-remote" command
1385 (no "set sysroot" or "file" commands are required). See "New remote
1388 * The "dump" command now supports verilog hex format.
1390 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1392 * On GNU/Linux, GDB and gdbserver are now able to access executable
1393 and shared library files without a "set sysroot" command when
1394 attaching to processes running in different mount namespaces from
1395 the debugger. This makes it possible to attach to processes in
1396 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1397 See "New remote packets" below.
1399 * The "tui reg" command now provides completion for all of the
1400 available register groups, including target specific groups.
1402 * The HISTSIZE environment variable is no longer read when determining
1403 the size of GDB's command history. GDB now instead reads the dedicated
1404 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1405 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1410 ** Memory ports can now be unbuffered.
1414 ** gdb.Objfile objects have a new attribute "username",
1415 which is the name of the objfile as specified by the user,
1416 without, for example, resolving symlinks.
1417 ** You can now write frame unwinders in Python.
1418 ** gdb.Type objects have a new method "optimized_out",
1419 returning optimized out gdb.Value instance of this type.
1420 ** gdb.Value objects have new methods "reference_value" and
1421 "const_value" which return a reference to the value and a
1422 "const" version of the value respectively.
1426 maint print symbol-cache
1427 Print the contents of the symbol cache.
1429 maint print symbol-cache-statistics
1430 Print statistics of symbol cache usage.
1432 maint flush-symbol-cache
1433 Flush the contents of the symbol cache.
1437 Start branch trace recording using Branch Trace Store (BTS) format.
1440 Evaluate expression by using the compiler and print result.
1444 Explicit commands for enabling and disabling tui mode.
1447 set mpx bound on i386 and amd64
1448 Support for bound table investigation on Intel MPX enabled applications.
1452 Start branch trace recording using Intel Processor Trace format.
1455 Print information about branch tracing internals.
1457 maint btrace packet-history
1458 Print the raw branch tracing data.
1460 maint btrace clear-packet-history
1461 Discard the stored raw branch tracing data.
1464 Discard all branch tracing data. It will be fetched and processed
1465 anew by the next "record" command.
1470 Renamed from "set debug dwarf2-die".
1471 show debug dwarf-die
1472 Renamed from "show debug dwarf2-die".
1474 set debug dwarf-read
1475 Renamed from "set debug dwarf2-read".
1476 show debug dwarf-read
1477 Renamed from "show debug dwarf2-read".
1479 maint set dwarf always-disassemble
1480 Renamed from "maint set dwarf2 always-disassemble".
1481 maint show dwarf always-disassemble
1482 Renamed from "maint show dwarf2 always-disassemble".
1484 maint set dwarf max-cache-age
1485 Renamed from "maint set dwarf2 max-cache-age".
1486 maint show dwarf max-cache-age
1487 Renamed from "maint show dwarf2 max-cache-age".
1489 set debug dwarf-line
1490 show debug dwarf-line
1491 Control display of debugging info regarding DWARF line processing.
1494 show max-completions
1495 Set the maximum number of candidates to be considered during
1496 completion. The default value is 200. This limit allows GDB
1497 to avoid generating large completion lists, the computation of
1498 which can cause the debugger to become temporarily unresponsive.
1500 set history remove-duplicates
1501 show history remove-duplicates
1502 Control the removal of duplicate history entries.
1504 maint set symbol-cache-size
1505 maint show symbol-cache-size
1506 Control the size of the symbol cache.
1508 set|show record btrace bts buffer-size
1509 Set and show the size of the ring buffer used for branch tracing in
1511 The obtained size may differ from the requested size. Use "info
1512 record" to see the obtained buffer size.
1514 set debug linux-namespaces
1515 show debug linux-namespaces
1516 Control display of debugging info regarding Linux namespaces.
1518 set|show record btrace pt buffer-size
1519 Set and show the size of the ring buffer used for branch tracing in
1520 Intel Processor Trace format.
1521 The obtained size may differ from the requested size. Use "info
1522 record" to see the obtained buffer size.
1524 maint set|show btrace pt skip-pad
1525 Set and show whether PAD packets are skipped when computing the
1528 * The command 'thread apply all' can now support new option '-ascending'
1529 to call its specified command for all threads in ascending order.
1531 * Python/Guile scripting
1533 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1534 special section named `.debug_gdb_scripts'.
1536 * New remote packets
1538 qXfer:btrace-conf:read
1539 Return the branch trace configuration for the current thread.
1541 Qbtrace-conf:bts:size
1542 Set the requested ring buffer size for branch tracing in BTS format.
1545 Enable Intel Procesor Trace-based branch tracing for the current
1546 process. The remote stub reports support for this packet to GDB's
1549 Qbtrace-conf:pt:size
1550 Set the requested ring buffer size for branch tracing in Intel Processor
1554 Indicates a memory breakpoint instruction was executed, irrespective
1555 of whether it was GDB that planted the breakpoint or the breakpoint
1556 is hardcoded in the program. This is required for correct non-stop
1560 Indicates the target stopped for a hardware breakpoint. This is
1561 required for correct non-stop mode operation.
1564 Return information about files on the remote system.
1566 qXfer:exec-file:read
1567 Return the full absolute name of the file that was executed to
1568 create a process running on the remote system.
1571 Select the filesystem on which vFile: operations with filename
1572 arguments will operate. This is required for GDB to be able to
1573 access files on remote targets where the remote stub does not
1574 share a common filesystem with the inferior(s).
1577 Indicates that a fork system call was executed.
1580 Indicates that a vfork system call was executed.
1582 vforkdone stop reason
1583 Indicates that a vfork child of the specified process has executed
1584 an exec or exit, allowing the vfork parent to resume execution.
1586 fork-events and vfork-events features in qSupported
1587 The qSupported packet allows GDB to request support for fork and
1588 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1589 and the qSupported response can contain the corresponding
1590 'stubfeatures'. Set and show commands can be used to display
1591 whether these features are enabled.
1593 * Extended-remote fork events
1595 ** GDB now has support for fork events on extended-remote Linux
1596 targets. For targets with Linux kernels 2.5.60 and later, this
1597 enables follow-fork-mode and detach-on-fork for both fork and
1598 vfork, as well as fork and vfork catchpoints.
1600 * The info record command now shows the recording format and the
1601 branch tracing configuration for the current thread when using
1602 the btrace record target.
1603 For the BTS format, it shows the ring buffer size.
1605 * GDB now has support for DTrace USDT (Userland Static Defined
1606 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1608 * GDB now supports access to vector registers on S/390 GNU/Linux
1611 * Removed command line options
1613 -xdb HP-UX XDB compatibility mode.
1615 * Removed targets and native configurations
1617 HP/PA running HP-UX hppa*-*-hpux*
1618 Itanium running HP-UX ia64-*-hpux*
1620 * New configure options
1623 This configure option allows the user to build GDB with support for
1624 Intel Processor Trace (default: auto). This requires libipt.
1626 --with-libipt-prefix=PATH
1627 Specify the path to the version of libipt that GDB should use.
1628 $PATH/include should contain the intel-pt.h header and
1629 $PATH/lib should contain the libipt.so library.
1631 *** Changes in GDB 7.9.1
1635 ** Xmethods can now specify a result type.
1637 *** Changes in GDB 7.9
1639 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1643 ** You can now access frame registers from Python scripts.
1644 ** New attribute 'producer' for gdb.Symtab objects.
1645 ** gdb.Objfile objects have a new attribute "progspace",
1646 which is the gdb.Progspace object of the containing program space.
1647 ** gdb.Objfile objects have a new attribute "owner".
1648 ** gdb.Objfile objects have a new attribute "build_id",
1649 which is the build ID generated when the file was built.
1650 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1651 ** A new event "gdb.clear_objfiles" has been added, triggered when
1652 selecting a new file to debug.
1653 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1654 ** New function gdb.lookup_objfile.
1656 New events which are triggered when GDB modifies the state of the
1659 ** gdb.events.inferior_call_pre: Function call is about to be made.
1660 ** gdb.events.inferior_call_post: Function call has just been made.
1661 ** gdb.events.memory_changed: A memory location has been altered.
1662 ** gdb.events.register_changed: A register has been altered.
1664 * New Python-based convenience functions:
1666 ** $_caller_is(name [, number_of_frames])
1667 ** $_caller_matches(regexp [, number_of_frames])
1668 ** $_any_caller_is(name [, number_of_frames])
1669 ** $_any_caller_matches(regexp [, number_of_frames])
1671 * GDB now supports the compilation and injection of source code into
1672 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1673 to compile the source code to object code, and if successful, inject
1674 and execute that code within the current context of the inferior.
1675 Currently the C language is supported. The commands used to
1676 interface with this new feature are:
1678 compile code [-raw|-r] [--] [source code]
1679 compile file [-raw|-r] filename
1683 demangle [-l language] [--] name
1684 Demangle "name" in the specified language, or the current language
1685 if elided. This command is renamed from the "maint demangle" command.
1686 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1687 as "maint demangler-warning".
1689 queue-signal signal-name-or-number
1690 Queue a signal to be delivered to the thread when it is resumed.
1692 add-auto-load-scripts-directory directory
1693 Add entries to the list of directories from which to load auto-loaded
1696 maint print user-registers
1697 List all currently available "user" registers.
1699 compile code [-r|-raw] [--] [source code]
1700 Compile, inject, and execute in the inferior the executable object
1701 code produced by compiling the provided source code.
1703 compile file [-r|-raw] filename
1704 Compile and inject into the inferior the executable object code
1705 produced by compiling the source code stored in the filename
1708 * On resume, GDB now always passes the signal the program had stopped
1709 for to the thread the signal was sent to, even if the user changed
1710 threads before resuming. Previously GDB would often (but not
1711 always) deliver the signal to the thread that happens to be current
1714 * Conversely, the "signal" command now consistently delivers the
1715 requested signal to the current thread. GDB now asks for
1716 confirmation if the program had stopped for a signal and the user
1717 switched threads meanwhile.
1719 * "breakpoint always-inserted" modes "off" and "auto" merged.
1721 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1722 won't remove breakpoints from the target until all threads stop,
1723 even in non-stop mode. The "auto" mode has been removed, and "off"
1724 is now the default mode.
1728 set debug symbol-lookup
1729 show debug symbol-lookup
1730 Control display of debugging info regarding symbol lookup.
1734 ** The -list-thread-groups command outputs an exit-code field for
1735 inferiors that have exited.
1739 MIPS SDE mips*-sde*-elf*
1743 Support for these obsolete configurations has been removed.
1745 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1746 SGI Irix-5.x mips-*-irix5*
1747 SGI Irix-6.x mips-*-irix6*
1748 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1749 VAX running Ultrix vax-*-ultrix*
1751 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1752 and "assf"), have been removed. Use the "sharedlibrary" command, or
1753 its alias "share", instead.
1755 *** Changes in GDB 7.8
1757 * New command line options
1760 This is an alias for the --data-directory option.
1762 * GDB supports printing and modifying of variable length automatic arrays
1763 as specified in ISO C99.
1765 * The ARM simulator now supports instruction level tracing
1766 with or without disassembly.
1770 GDB now has support for scripting using Guile. Whether this is
1771 available is determined at configure time.
1772 Guile version 2.0 or greater is required.
1773 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1775 * New commands (for set/show, see "New options" below)
1779 Invoke CODE by passing it to the Guile interpreter.
1783 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1785 info auto-load guile-scripts [regexp]
1786 Print the list of automatically loaded Guile scripts.
1788 * The source command is now capable of sourcing Guile scripts.
1789 This feature is dependent on the debugger being built with Guile support.
1793 set print symbol-loading (off|brief|full)
1794 show print symbol-loading
1795 Control whether to print informational messages when loading symbol
1796 information for a file. The default is "full", but when debugging
1797 programs with large numbers of shared libraries the amount of output
1798 becomes less useful.
1800 set guile print-stack (none|message|full)
1801 show guile print-stack
1802 Show a stack trace when an error is encountered in a Guile script.
1804 set auto-load guile-scripts (on|off)
1805 show auto-load guile-scripts
1806 Control auto-loading of Guile script files.
1808 maint ada set ignore-descriptive-types (on|off)
1809 maint ada show ignore-descriptive-types
1810 Control whether the debugger should ignore descriptive types in Ada
1811 programs. The default is not to ignore the descriptive types. See
1812 the user manual for more details on descriptive types and the intended
1813 usage of this option.
1815 set auto-connect-native-target
1817 Control whether GDB is allowed to automatically connect to the
1818 native target for the run, attach, etc. commands when not connected
1819 to any target yet. See also "target native" below.
1821 set record btrace replay-memory-access (read-only|read-write)
1822 show record btrace replay-memory-access
1823 Control what memory accesses are allowed during replay.
1825 maint set target-async (on|off)
1826 maint show target-async
1827 This controls whether GDB targets operate in synchronous or
1828 asynchronous mode. Normally the default is asynchronous, if it is
1829 available; but this can be changed to more easily debug problems
1830 occurring only in synchronous mode.
1832 set mi-async (on|off)
1834 Control whether MI asynchronous mode is preferred. This supersedes
1835 "set target-async" of previous GDB versions.
1837 * "set target-async" is deprecated as a CLI option and is now an alias
1838 for "set mi-async" (only puts MI into async mode).
1840 * Background execution commands (e.g., "c&", "s&", etc.) are now
1841 possible ``out of the box'' if the target supports them. Previously
1842 the user would need to explicitly enable the possibility with the
1843 "set target-async on" command.
1845 * New features in the GDB remote stub, GDBserver
1847 ** New option --debug-format=option1[,option2,...] allows one to add
1848 additional text to each output. At present only timestamps
1849 are supported: --debug-format=timestamps.
1850 Timestamps can also be turned on with the
1851 "monitor set debug-format timestamps" command from GDB.
1853 * The 'record instruction-history' command now starts counting instructions
1854 at one. This also affects the instruction ranges reported by the
1855 'record function-call-history' command when given the /i modifier.
1857 * The command 'record function-call-history' supports a new modifier '/c' to
1858 indent the function names based on their call stack depth.
1859 The fields for the '/i' and '/l' modifier have been reordered.
1860 The source line range is now prefixed with 'at'.
1861 The instruction range is now prefixed with 'inst'.
1862 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1863 "record instruction-history" and "list" commands.
1865 * The ranges given as arguments to the 'record function-call-history' and
1866 'record instruction-history' commands are now inclusive.
1868 * The btrace record target now supports the 'record goto' command.
1869 For locations inside the execution trace, the back trace is computed
1870 based on the information stored in the execution trace.
1872 * The btrace record target supports limited reverse execution and replay.
1873 The target does not record data and therefore does not allow reading
1874 memory or registers.
1876 * The "catch syscall" command now works on s390*-linux* targets.
1878 * The "compare-sections" command is no longer specific to target
1879 remote. It now works with all targets.
1881 * All native targets are now consistently called "native".
1882 Consequently, the "target child", "target GNU", "target djgpp",
1883 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1884 commands have been replaced with "target native". The QNX/NTO port
1885 leaves the "procfs" target in place and adds a "native" target for
1886 consistency with other ports. The impact on users should be minimal
1887 as these commands previously either throwed an error, or were
1888 no-ops. The target's name is visible in the output of the following
1889 commands: "help target", "info target", "info files", "maint print
1892 * The "target native" command now connects to the native target. This
1893 can be used to launch native programs even when "set
1894 auto-connect-native-target" is set to off.
1896 * GDB now supports access to Intel MPX registers on GNU/Linux.
1898 * Support for Intel AVX-512 registers on GNU/Linux.
1899 Support displaying and modifying Intel AVX-512 registers
1900 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1902 * New remote packets
1904 qXfer:btrace:read's annex
1905 The qXfer:btrace:read packet supports a new annex 'delta' to read
1906 branch trace incrementally.
1910 ** Valid Python operations on gdb.Value objects representing
1911 structs/classes invoke the corresponding overloaded operators if
1913 ** New `Xmethods' feature in the Python API. Xmethods are
1914 additional methods or replacements for existing methods of a C++
1915 class. This feature is useful for those cases where a method
1916 defined in C++ source code could be inlined or optimized out by
1917 the compiler, making it unavailable to GDB.
1920 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1922 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1923 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1924 its alias "share", instead.
1926 * The commands "set remotebaud" and "show remotebaud" are no longer
1927 supported. Use "set serial baud" and "show serial baud" (respectively)
1932 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1933 target-async". The latter is left as a deprecated alias of the
1934 former for backward compatibility. If the target supports it,
1935 CLI background execution commands are now always possible by
1936 default, independently of whether the frontend stated a
1937 preference for asynchronous execution with "-gdb-set mi-async".
1938 Previously "-gdb-set target-async off" affected both MI execution
1939 commands and CLI execution commands.
1941 *** Changes in GDB 7.7
1943 * Improved support for process record-replay and reverse debugging on
1944 arm*-linux* targets. Support for thumb32 and syscall instruction
1945 recording has been added.
1947 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1949 * GDB now supports Fission DWP file format version 2.
1950 http://gcc.gnu.org/wiki/DebugFission
1952 * New convenience function "$_isvoid", to check whether an expression
1953 is void. A void expression is an expression where the type of the
1954 result is "void". For example, some convenience variables may be
1955 "void" when evaluated (e.g., "$_exitcode" before the execution of
1956 the program being debugged; or an undefined convenience variable).
1957 Another example, when calling a function whose return type is
1960 * The "maintenance print objfiles" command now takes an optional regexp.
1962 * The "catch syscall" command now works on arm*-linux* targets.
1964 * GDB now consistently shows "<not saved>" when printing values of
1965 registers the debug info indicates have not been saved in the frame
1966 and there's nowhere to retrieve them from
1967 (callee-saved/call-clobbered registers):
1972 (gdb) info registers rax
1975 Before, the former would print "<optimized out>", and the latter
1976 "*value not available*".
1978 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1983 ** Frame filters and frame decorators have been added.
1984 ** Temporary breakpoints are now supported.
1985 ** Line tables representation has been added.
1986 ** New attribute 'parent_type' for gdb.Field objects.
1987 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1988 ** New attribute 'name' for gdb.Type objects.
1992 Nios II ELF nios2*-*-elf
1993 Nios II GNU/Linux nios2*-*-linux
1994 Texas Instruments MSP430 msp430*-*-elf
1996 * Removed native configurations
1998 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1999 been removed. ELF variants of these configurations are kept supported.
2001 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2002 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2003 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2004 i[34567]86-*-openbsd3.[0-3]
2005 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2006 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2007 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2011 Like "catch throw", but catches a re-thrown exception.
2012 maint check-psymtabs
2013 Renamed from old "maint check-symtabs".
2015 Perform consistency checks on symtabs.
2016 maint expand-symtabs
2017 Expand symtabs matching an optional regexp.
2020 Display the details of GDB configure-time options.
2022 maint set|show per-command
2023 maint set|show per-command space
2024 maint set|show per-command time
2025 maint set|show per-command symtab
2026 Enable display of per-command gdb resource usage.
2028 remove-symbol-file FILENAME
2029 remove-symbol-file -a ADDRESS
2030 Remove a symbol file added via add-symbol-file. The file to remove
2031 can be identified by its filename or by an address that lies within
2032 the boundaries of this symbol file in memory.
2035 info exceptions REGEXP
2036 Display the list of Ada exceptions defined in the program being
2037 debugged. If provided, only the exceptions whose names match REGEXP
2042 set debug symfile off|on
2044 Control display of debugging info regarding reading symbol files and
2045 symbol tables within those files
2047 set print raw frame-arguments
2048 show print raw frame-arguments
2049 Set/show whether to print frame arguments in raw mode,
2050 disregarding any defined pretty-printers.
2052 set remote trace-status-packet
2053 show remote trace-status-packet
2054 Set/show the use of remote protocol qTStatus packet.
2058 Control display of debugging messages related to Nios II targets.
2062 Control whether target-assisted range stepping is enabled.
2064 set startup-with-shell
2065 show startup-with-shell
2066 Specifies whether Unix child processes are started via a shell or
2071 Use the target memory cache for accesses to the code segment. This
2072 improves performance of remote debugging (particularly disassembly).
2074 * You can now use a literal value 'unlimited' for options that
2075 interpret 0 or -1 as meaning "unlimited". E.g., "set
2076 trace-buffer-size unlimited" is now an alias for "set
2077 trace-buffer-size -1" and "set height unlimited" is now an alias for
2080 * The "set debug symtab-create" debugging option of GDB has been changed to
2081 accept a verbosity level. 0 means "off", 1 provides basic debugging
2082 output, and values of 2 or greater provides more verbose output.
2084 * New command-line options
2086 Display the details of GDB configure-time options.
2088 * The command 'tsave' can now support new option '-ctf' to save trace
2089 buffer in Common Trace Format.
2091 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2094 * GDB now implements the the C++ 'typeid' operator.
2096 * The new convenience variable $_exception holds the exception being
2097 thrown or caught at an exception-related catchpoint.
2099 * The exception-related catchpoints, like "catch throw", now accept a
2100 regular expression which can be used to filter exceptions by type.
2102 * The new convenience variable $_exitsignal is automatically set to
2103 the terminating signal number when the program being debugged dies
2104 due to an uncaught signal.
2108 ** All MI commands now accept an optional "--language" option.
2109 Support for this feature can be verified by using the "-list-features"
2110 command, which should contain "language-option".
2112 ** The new command -info-gdb-mi-command allows the user to determine
2113 whether a GDB/MI command is supported or not.
2115 ** The "^error" result record returned when trying to execute an undefined
2116 GDB/MI command now provides a variable named "code" whose content is the
2117 "undefined-command" error code. Support for this feature can be verified
2118 by using the "-list-features" command, which should contain
2119 "undefined-command-error-code".
2121 ** The -trace-save MI command can optionally save trace buffer in Common
2124 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2126 ** The command -data-list-register-values now accepts an optional
2127 "--skip-unavailable" option. When used, only the available registers
2130 ** The new command -trace-frame-collected dumps collected variables,
2131 computed expressions, tvars, memory and registers in a traceframe.
2133 ** The commands -stack-list-locals, -stack-list-arguments and
2134 -stack-list-variables now accept an option "--skip-unavailable".
2135 When used, only the available locals or arguments are displayed.
2137 ** The -exec-run command now accepts an optional "--start" option.
2138 When used, the command follows the same semantics as the "start"
2139 command, stopping the program's execution at the start of its
2140 main subprogram. Support for this feature can be verified using
2141 the "-list-features" command, which should contain
2142 "exec-run-start-option".
2144 ** The new commands -catch-assert and -catch-exceptions insert
2145 catchpoints stopping the program when Ada exceptions are raised.
2147 ** The new command -info-ada-exceptions provides the equivalent of
2148 the new "info exceptions" command.
2150 * New system-wide configuration scripts
2151 A GDB installation now provides scripts suitable for use as system-wide
2152 configuration scripts for the following systems:
2156 * GDB now supports target-assigned range stepping with remote targets.
2157 This improves the performance of stepping source lines by reducing
2158 the number of control packets from/to GDB. See "New remote packets"
2161 * GDB now understands the element 'tvar' in the XML traceframe info.
2162 It has the id of the collected trace state variables.
2164 * On S/390 targets that provide the transactional-execution feature,
2165 the program interruption transaction diagnostic block (TDB) is now
2166 represented as a number of additional "registers" in GDB.
2168 * New remote packets
2172 The vCont packet supports a new 'r' action, that tells the remote
2173 stub to step through an address range itself, without GDB
2174 involvemement at each single-step.
2176 qXfer:libraries-svr4:read's annex
2177 The previously unused annex of the qXfer:libraries-svr4:read packet
2178 is now used to support passing an argument list. The remote stub
2179 reports support for this argument list to GDB's qSupported query.
2180 The defined arguments are "start" and "prev", used to reduce work
2181 necessary for library list updating, resulting in significant
2184 * New features in the GDB remote stub, GDBserver
2186 ** GDBserver now supports target-assisted range stepping. Currently
2187 enabled on x86/x86_64 GNU/Linux targets.
2189 ** GDBserver now adds element 'tvar' in the XML in the reply to
2190 'qXfer:traceframe-info:read'. It has the id of the collected
2191 trace state variables.
2193 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2196 * New 'z' formatter for printing and examining memory, this displays the
2197 value as hexadecimal zero padded on the left to the size of the type.
2199 * GDB can now use Windows x64 unwinding data.
2201 * The "set remotebaud" command has been replaced by "set serial baud".
2202 Similarly, "show remotebaud" has been replaced by "show serial baud".
2203 The "set remotebaud" and "show remotebaud" commands are still available
2204 to provide backward compatibility with older versions of GDB.
2206 *** Changes in GDB 7.6
2208 * Target record has been renamed to record-full.
2209 Record/replay is now enabled with the "record full" command.
2210 This also affects settings that are associated with full record/replay
2211 that have been moved from "set/show record" to "set/show record full":
2213 set|show record full insn-number-max
2214 set|show record full stop-at-limit
2215 set|show record full memory-query
2217 * A new record target "record-btrace" has been added. The new target
2218 uses hardware support to record the control-flow of a process. It
2219 does not support replaying the execution, but it implements the
2220 below new commands for investigating the recorded execution log.
2221 This new recording method can be enabled using:
2225 The "record-btrace" target is only available on Intel Atom processors
2226 and requires a Linux kernel 2.6.32 or later.
2228 * Two new commands have been added for record/replay to give information
2229 about the recorded execution without having to replay the execution.
2230 The commands are only supported by "record btrace".
2232 record instruction-history prints the execution history at
2233 instruction granularity
2235 record function-call-history prints the execution history at
2236 function granularity
2238 * New native configurations
2240 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2241 FreeBSD/powerpc powerpc*-*-freebsd
2242 x86_64/Cygwin x86_64-*-cygwin*
2243 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2247 ARM AArch64 aarch64*-*-elf
2248 ARM AArch64 GNU/Linux aarch64*-*-linux
2249 Lynx 178 PowerPC powerpc-*-lynx*178
2250 x86_64/Cygwin x86_64-*-cygwin*
2251 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2253 * If the configured location of system.gdbinit file (as given by the
2254 --with-system-gdbinit option at configure time) is in the
2255 data-directory (as specified by --with-gdb-datadir at configure
2256 time) or in one of its subdirectories, then GDB will look for the
2257 system-wide init file in the directory specified by the
2258 --data-directory command-line option.
2260 * New command line options:
2262 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2263 other initialization files, unlike -nx which disables all of them.
2265 * Removed command line options
2267 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2270 * The 'ptype' and 'whatis' commands now accept an argument to control
2273 * 'info proc' now works on some core files.
2277 ** Vectors can be created with gdb.Type.vector.
2279 ** Python's atexit.register now works in GDB.
2281 ** Types can be pretty-printed via a Python API.
2283 ** Python 3 is now supported (in addition to Python 2.4 or later)
2285 ** New class gdb.Architecture exposes GDB's internal representation
2286 of architecture in the Python API.
2288 ** New method Frame.architecture returns the gdb.Architecture object
2289 corresponding to the frame's architecture.
2291 * New Python-based convenience functions:
2293 ** $_memeq(buf1, buf2, length)
2294 ** $_streq(str1, str2)
2296 ** $_regex(str, regex)
2298 * The 'cd' command now defaults to using '~' (the home directory) if not
2301 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2302 default for GCC since November 2000.
2304 * The command 'forward-search' can now be abbreviated as 'fo'.
2306 * The command 'info tracepoints' can now display 'installed on target'
2307 or 'not installed on target' for each non-pending location of tracepoint.
2309 * New configure options
2311 --enable-libmcheck/--disable-libmcheck
2312 By default, development versions are built with -lmcheck on hosts
2313 that support it, in order to help track memory corruption issues.
2314 Release versions, on the other hand, are built without -lmcheck
2315 by default. The --enable-libmcheck/--disable-libmcheck configure
2316 options allow the user to override that default.
2317 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2318 This configure option allows the user to build GDB with
2319 libbabeltrace using which GDB can read Common Trace Format data.
2321 * New commands (for set/show, see "New options" below)
2324 Catch signals. This is similar to "handle", but allows commands and
2325 conditions to be attached.
2328 List the BFDs known to GDB.
2330 python-interactive [command]
2332 Start a Python interactive prompt, or evaluate the optional command
2333 and print the result of expressions.
2336 "py" is a new alias for "python".
2338 enable type-printer [name]...
2339 disable type-printer [name]...
2340 Enable or disable type printers.
2344 ** For the Renesas Super-H architecture, the "regs" command has been removed
2345 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2350 set print type methods (on|off)
2351 show print type methods
2352 Control whether method declarations are displayed by "ptype".
2353 The default is to show them.
2355 set print type typedefs (on|off)
2356 show print type typedefs
2357 Control whether typedef definitions are displayed by "ptype".
2358 The default is to show them.
2360 set filename-display basename|relative|absolute
2361 show filename-display
2362 Control the way in which filenames is displayed.
2363 The default is "relative", which preserves previous behavior.
2365 set trace-buffer-size
2366 show trace-buffer-size
2367 Request target to change the size of trace buffer.
2369 set remote trace-buffer-size-packet auto|on|off
2370 show remote trace-buffer-size-packet
2371 Control the use of the remote protocol `QTBuffer:size' packet.
2375 Control display of debugging messages related to ARM AArch64.
2378 set debug coff-pe-read
2379 show debug coff-pe-read
2380 Control display of debugging messages related to reading of COFF/PE
2385 Control display of debugging messages related to Mach-O symbols
2388 set debug notification
2389 show debug notification
2390 Control display of debugging info for async remote notification.
2394 ** Command parameter changes are now notified using new async record
2395 "=cmd-param-changed".
2396 ** Trace frame changes caused by command "tfind" are now notified using
2397 new async record "=traceframe-changed".
2398 ** The creation, deletion and modification of trace state variables
2399 are now notified using new async records "=tsv-created",
2400 "=tsv-deleted" and "=tsv-modified".
2401 ** The start and stop of process record are now notified using new
2402 async record "=record-started" and "=record-stopped".
2403 ** Memory changes are now notified using new async record
2405 ** The data-disassemble command response will include a "fullname" field
2406 containing the absolute file name when source has been requested.
2407 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2408 command, to allow pattern filling of memory areas.
2409 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2410 library load/unload events.
2411 ** The response to breakpoint commands and breakpoint async records
2412 includes an "installed" field containing a boolean state about each
2413 non-pending tracepoint location is whether installed on target or not.
2414 ** Output of the "-trace-status" command includes a "trace-file" field
2415 containing the name of the trace file being examined. This field is
2416 optional, and only present when examining a trace file.
2417 ** The "fullname" field is now always present along with the "file" field,
2418 even if the file cannot be found by GDB.
2420 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2421 You must have the LZMA library available when configuring GDB for this
2422 feature to be enabled. For more information, see:
2423 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2425 * New remote packets
2428 Set the size of trace buffer. The remote stub reports support for this
2429 packet to gdb's qSupported query.
2432 Enable Branch Trace Store (BTS)-based branch tracing for the current
2433 thread. The remote stub reports support for this packet to gdb's
2437 Disable branch tracing for the current thread. The remote stub reports
2438 support for this packet to gdb's qSupported query.
2441 Read the traced branches for the current thread. The remote stub
2442 reports support for this packet to gdb's qSupported query.
2444 *** Changes in GDB 7.5
2446 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2447 for more x32 ABI info.
2449 * GDB now supports access to MIPS DSP registers on Linux targets.
2451 * GDB now supports debugging microMIPS binaries.
2453 * The "info os" command on GNU/Linux can now display information on
2454 several new classes of objects managed by the operating system:
2455 "info os procgroups" lists process groups
2456 "info os files" lists file descriptors
2457 "info os sockets" lists internet-domain sockets
2458 "info os shm" lists shared-memory regions
2459 "info os semaphores" lists semaphores
2460 "info os msg" lists message queues
2461 "info os modules" lists loaded kernel modules
2463 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2464 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2465 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2466 options and inspect the probe arguments using the new $_probe_arg family
2467 of convenience variables. You can obtain more information about SystemTap
2468 in <http://sourceware.org/systemtap/>.
2470 * GDB now supports reversible debugging on ARM, it allows you to
2471 debug basic ARM and THUMB instructions, and provides
2472 record/replay support.
2474 * The option "symbol-reloading" has been deleted as it is no longer used.
2478 ** GDB commands implemented in Python can now be put in command class
2481 ** The "maint set python print-stack on|off" is now deleted.
2483 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2484 apply "flag enum"-style pretty-printing to any enum.
2486 ** gdb.lookup_symbol can now work when there is no current frame.
2488 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2489 the source at which the symbol was defined.
2491 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2492 method 'value'. The former indicates whether the symbol needs a
2493 frame in order to compute its value, and the latter computes the
2496 ** A new method 'referenced_value' on gdb.Value objects which can
2497 dereference pointer as well as C++ reference values.
2499 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2500 which return the global and static blocks (as gdb.Block objects),
2501 of the underlying symbol table, respectively.
2503 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2504 object associated with a PC value.
2506 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2507 of the address range occupied by code for the current source line.
2509 * Go language support.
2510 GDB now supports debugging programs written in the Go programming
2513 * GDBserver now supports stdio connections.
2514 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2516 * The binary "gdbtui" can no longer be built or installed.
2517 Use "gdb -tui" instead.
2519 * GDB will now print "flag" enums specially. A flag enum is one where
2520 all the enumerator values have no bits in common when pairwise
2521 "and"ed. When printing a value whose type is a flag enum, GDB will
2522 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2523 (gdb) print (enum E) 3
2526 * The filename part of a linespec will now match trailing components
2527 of a source file name. For example, "break gcc/expr.c:1000" will
2528 now set a breakpoint in build/gcc/expr.c, but not
2529 build/libcpp/expr.c.
2531 * The "info proc" and "generate-core-file" commands will now also
2532 work on remote targets connected to GDBserver on Linux.
2534 * The command "info catch" has been removed. It has been disabled
2535 since December 2007.
2537 * The "catch exception" and "catch assert" commands now accept
2538 a condition at the end of the command, much like the "break"
2539 command does. For instance:
2541 (gdb) catch exception Constraint_Error if Barrier = True
2543 Previously, it was possible to add a condition to such catchpoints,
2544 but it had to be done as a second step, after the catchpoint had been
2545 created, using the "condition" command.
2547 * The "info static-tracepoint-marker" command will now also work on
2548 native Linux targets with in-process agent.
2550 * GDB can now set breakpoints on inlined functions.
2552 * The .gdb_index section has been updated to include symbols for
2553 inlined functions. GDB will ignore older .gdb_index sections by
2554 default, which could cause symbol files to be loaded more slowly
2555 until their .gdb_index sections can be recreated. The new command
2556 "set use-deprecated-index-sections on" will cause GDB to use any older
2557 .gdb_index sections it finds. This will restore performance, but the
2558 ability to set breakpoints on inlined functions will be lost in symbol
2559 files with older .gdb_index sections.
2561 The .gdb_index section has also been updated to record more information
2562 about each symbol. This speeds up the "info variables", "info functions"
2563 and "info types" commands when used with programs having the .gdb_index
2564 section, as well as speeding up debugging with shared libraries using
2565 the .gdb_index section.
2567 * Ada support for GDB/MI Variable Objects has been added.
2569 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2574 ** New command -info-os is the MI equivalent of "info os".
2576 ** Output logs ("set logging" and related) now include MI output.
2580 ** "set use-deprecated-index-sections on|off"
2581 "show use-deprecated-index-sections on|off"
2582 Controls the use of deprecated .gdb_index sections.
2584 ** "catch load" and "catch unload" can be used to stop when a shared
2585 library is loaded or unloaded, respectively.
2587 ** "enable count" can be used to auto-disable a breakpoint after
2590 ** "info vtbl" can be used to show the virtual method tables for
2591 C++ and Java objects.
2593 ** "explore" and its sub commands "explore value" and "explore type"
2594 can be used to recursively explore values and types of
2595 expressions. These commands are available only if GDB is
2596 configured with '--with-python'.
2598 ** "info auto-load" shows status of all kinds of auto-loaded files,
2599 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2600 sequences of commands files, "info auto-load python-scripts"
2601 shows status of auto-loading Python script files,
2602 "info auto-load local-gdbinit" shows status of loading init file
2603 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2604 status of inferior specific thread debugging shared library loading.
2606 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2607 and "show auto-load-scripts" commands have been deprecated, use their
2608 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2609 and "show auto-load python-scripts" counterparts instead.
2611 ** "dprintf location,format,args..." creates a dynamic printf, which
2612 is basically a breakpoint that does a printf and immediately
2613 resumes your program's execution, so it is like a printf that you
2614 can insert dynamically at runtime instead of at compiletime.
2616 ** "set print symbol"
2618 Controls whether GDB attempts to display the symbol, if any,
2619 corresponding to addresses it prints. This defaults to "on", but
2620 you can set it to "off" to restore GDB's previous behavior.
2622 * Deprecated commands
2624 ** For the Renesas Super-H architecture, the "regs" command has been
2625 deprecated, and "info all-registers" should be used instead.
2629 Renesas RL78 rl78-*-elf
2630 HP OpenVMS ia64 ia64-hp-openvms*
2632 * GDBserver supports evaluation of breakpoint conditions. When
2633 support is advertised by GDBserver, GDB may be told to send the
2634 breakpoint conditions in bytecode form to GDBserver. GDBserver
2635 will only report the breakpoint trigger to GDB when its condition
2640 set mips compression
2641 show mips compression
2642 Select the compressed ISA encoding used in functions that have no symbol
2643 information available. The encoding can be set to either of:
2646 and is updated automatically from ELF file flags if available.
2648 set breakpoint condition-evaluation
2649 show breakpoint condition-evaluation
2650 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2651 GDBserver ("target"). Default option "auto" chooses the most efficient
2653 This option can improve debugger efficiency depending on the speed of the
2657 Disable auto-loading globally.
2660 Show auto-loading setting of all kinds of auto-loaded files.
2662 set auto-load gdb-scripts on|off
2663 show auto-load gdb-scripts
2664 Control auto-loading of GDB canned sequences of commands files.
2666 set auto-load python-scripts on|off
2667 show auto-load python-scripts
2668 Control auto-loading of Python script files.
2670 set auto-load local-gdbinit on|off
2671 show auto-load local-gdbinit
2672 Control loading of init file (.gdbinit) from current directory.
2674 set auto-load libthread-db on|off
2675 show auto-load libthread-db
2676 Control auto-loading of inferior specific thread debugging shared library.
2678 set auto-load scripts-directory <dir1>[:<dir2>...]
2679 show auto-load scripts-directory
2680 Set a list of directories from which to load auto-loaded scripts.
2681 Automatically loaded Python scripts and GDB scripts are located in one
2682 of the directories listed by this option.
2683 The delimiter (':' above) may differ according to the host platform.
2685 set auto-load safe-path <dir1>[:<dir2>...]
2686 show auto-load safe-path
2687 Set a list of directories from which it is safe to auto-load files.
2688 The delimiter (':' above) may differ according to the host platform.
2690 set debug auto-load on|off
2691 show debug auto-load
2692 Control display of debugging info for auto-loading the files above.
2694 set dprintf-style gdb|call|agent
2696 Control the way in which a dynamic printf is performed; "gdb"
2697 requests a GDB printf command, while "call" causes dprintf to call a
2698 function in the inferior. "agent" requests that the target agent
2699 (such as GDBserver) do the printing.
2701 set dprintf-function <expr>
2702 show dprintf-function
2703 set dprintf-channel <expr>
2704 show dprintf-channel
2705 Set the function and optional first argument to the call when using
2706 the "call" style of dynamic printf.
2708 set disconnected-dprintf on|off
2709 show disconnected-dprintf
2710 Control whether agent-style dynamic printfs continue to be in effect
2711 after GDB disconnects.
2713 * New configure options
2715 --with-auto-load-dir
2716 Configure default value for the 'set auto-load scripts-directory'
2717 setting above. It defaults to '$debugdir:$datadir/auto-load',
2718 $debugdir representing global debugging info directories (available
2719 via 'show debug-file-directory') and $datadir representing GDB's data
2720 directory (available via 'show data-directory').
2722 --with-auto-load-safe-path
2723 Configure default value for the 'set auto-load safe-path' setting
2724 above. It defaults to the --with-auto-load-dir setting.
2726 --without-auto-load-safe-path
2727 Set 'set auto-load safe-path' to '/', effectively disabling this
2730 * New remote packets
2732 z0/z1 conditional breakpoints extension
2734 The z0/z1 breakpoint insertion packets have been extended to carry
2735 a list of conditional expressions over to the remote stub depending on the
2736 condition evaluation mode. The use of this extension can be controlled
2737 via the "set remote conditional-breakpoints-packet" command.
2741 Specify the signals which the remote stub may pass to the debugged
2742 program without GDB involvement.
2744 * New command line options
2746 --init-command=FILE, -ix Like --command, -x but execute it
2747 before loading inferior.
2748 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2749 execute it before loading inferior.
2751 *** Changes in GDB 7.4
2753 * GDB now handles ambiguous linespecs more consistently; the existing
2754 FILE:LINE support has been expanded to other types of linespecs. A
2755 breakpoint will now be set on all matching locations in all
2756 inferiors, and locations will be added or removed according to
2759 * GDB now allows you to skip uninteresting functions and files when
2760 stepping with the "skip function" and "skip file" commands.
2762 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2763 and "show remote hardware-watchpoint-length-limit". These allows to
2764 set or show the maximum length limit (in bytes) of a remote
2765 target hardware watchpoint.
2767 This allows e.g. to use "unlimited" hardware watchpoints with the
2768 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2769 watchpoints are slower than real hardware watchpoints but are
2770 significantly faster than gdb software watchpoints.
2774 ** The register_pretty_printer function in module gdb.printing now takes
2775 an optional `replace' argument. If True, the new printer replaces any
2778 ** The "maint set python print-stack on|off" command has been
2779 deprecated and will be deleted in GDB 7.5.
2780 A new command: "set python print-stack none|full|message" has
2781 replaced it. Additionally, the default for "print-stack" is
2782 now "message", which just prints the error message without
2785 ** A prompt substitution hook (prompt_hook) is now available to the
2788 ** A new Python module, gdb.prompt has been added to the GDB Python
2789 modules library. This module provides functionality for
2790 escape sequences in prompts (used by set/show
2791 extended-prompt). These escape sequences are replaced by their
2792 corresponding value.
2794 ** Python commands and convenience-functions located in
2795 'data-directory'/python/gdb/command and
2796 'data-directory'/python/gdb/function are now automatically loaded
2799 ** Blocks now provide four new attributes. global_block and
2800 static_block will return the global and static blocks
2801 respectively. is_static and is_global are boolean attributes
2802 that indicate if the block is one of those two types.
2804 ** Symbols now provide the "type" attribute, the type of the symbol.
2806 ** The "gdb.breakpoint" function has been deprecated in favor of
2809 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2810 of a function. This class is based on the "finish" command
2811 available in the CLI.
2813 ** Type objects for struct and union types now allow access to
2814 the fields using standard Python dictionary (mapping) methods.
2815 For example, "some_type['myfield']" now works, as does
2816 "some_type.items()".
2818 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2821 ** A new function, "deep_items" has been added to the gdb.types
2822 module in the GDB Python modules library. This function returns
2823 an iterator over the fields of a struct or union type. Unlike
2824 the standard Python "iteritems" method, it will recursively traverse
2825 any anonymous fields.
2829 ** "*stopped" events can report several new "reason"s, such as
2832 ** Breakpoint changes are now notified using new async records, like
2833 "=breakpoint-modified".
2835 ** New command -ada-task-info.
2837 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2838 $sdir specifies the default system locations of shared libraries.
2839 $pdir specifies the directory where the libpthread used by the application
2842 GDB no longer looks in $sdir and $pdir after it has searched the directories
2843 mentioned in libthread-db-search-path. If you want to search those
2844 directories, they must be specified in libthread-db-search-path.
2845 The default value of libthread-db-search-path on GNU/Linux and Solaris
2846 systems is now "$sdir:$pdir".
2848 $pdir is not supported by gdbserver, it is currently ignored.
2849 $sdir is supported by gdbserver.
2851 * New configure option --with-iconv-bin.
2852 When using the internationalization support like the one in the GNU C
2853 library, GDB will invoke the "iconv" program to get a list of supported
2854 character sets. If this program lives in a non-standard location, one can
2855 use this option to specify where to find it.
2857 * When natively debugging programs on PowerPC BookE processors running
2858 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2859 watchpoints, which specify a mask in addition to an address to watch.
2860 The mask specifies that some bits of an address (the bits which are
2861 reset in the mask) should be ignored when matching the address accessed
2862 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2863 section in the user manual for more details.
2865 * The new option --once causes GDBserver to stop listening for connections once
2866 the first connection is made. The listening port used by GDBserver will
2867 become available after that.
2869 * New commands "info macros" and "alias" have been added.
2871 * New function parameters suffix @entry specifies value of function parameter
2872 at the time the function got called. Entry values are available only since
2878 "!" is now an alias of the "shell" command.
2879 Note that no space is needed between "!" and SHELL COMMAND.
2883 watch EXPRESSION mask MASK_VALUE
2884 The watch command now supports the mask argument which allows creation
2885 of masked watchpoints, if the current architecture supports this feature.
2887 info auto-load-scripts [REGEXP]
2888 This command was formerly named "maintenance print section-scripts".
2889 It is now generally useful and is no longer a maintenance-only command.
2891 info macro [-all] [--] MACRO
2892 The info macro command has new options `-all' and `--'. The first for
2893 printing all definitions of a macro. The second for explicitly specifying
2894 the end of arguments and the beginning of the macro name in case the macro
2895 name starts with a hyphen.
2897 collect[/s] EXPRESSIONS
2898 The tracepoint collect command now takes an optional modifier "/s"
2899 that directs it to dereference pointer-to-character types and
2900 collect the bytes of memory up to a zero byte. The behavior is
2901 similar to what you see when you use the regular print command on a
2902 string. An optional integer following the "/s" sets a bound on the
2903 number of bytes that will be collected.
2906 The trace start command now interprets any supplied arguments as a
2907 note to be recorded with the trace run, with an effect similar to
2908 setting the variable trace-notes.
2911 The trace stop command now interprets any arguments as a note to be
2912 mentioned along with the tstatus report that the trace was stopped
2913 with a command. The effect is similar to setting the variable
2916 * Tracepoints can now be enabled and disabled at any time after a trace
2917 experiment has been started using the standard "enable" and "disable"
2918 commands. It is now possible to start a trace experiment with no enabled
2919 tracepoints; GDB will display a warning, but will allow the experiment to
2920 begin, assuming that tracepoints will be enabled as needed while the trace
2923 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2924 locations with 4-byte instructions, when they were previously
2925 limited to locations with instructions of 5 bytes or longer.
2929 set debug dwarf2-read
2930 show debug dwarf2-read
2931 Turns on or off display of debugging messages related to reading
2932 DWARF debug info. The default is off.
2934 set debug symtab-create
2935 show debug symtab-create
2936 Turns on or off display of debugging messages related to symbol table
2937 creation. The default is off.
2940 show extended-prompt
2941 Set the GDB prompt, and allow escape sequences to be inserted to
2942 display miscellaneous information (see 'help set extended-prompt'
2943 for the list of sequences). This prompt (and any information
2944 accessed through the escape sequences) is updated every time the
2945 prompt is displayed.
2947 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2948 show print entry-values
2949 Set printing of frame argument values at function entry. In some cases
2950 GDB can determine the value of function argument which was passed by the
2951 function caller, even if the value was modified inside the called function.
2953 set debug entry-values
2954 show debug entry-values
2955 Control display of debugging info for determining frame argument values at
2956 function entry and virtual tail call frames.
2958 set basenames-may-differ
2959 show basenames-may-differ
2960 Set whether a source file may have multiple base names.
2961 (A "base name" is the name of a file with the directory part removed.
2962 Example: The base name of "/home/user/hello.c" is "hello.c".)
2963 If set, GDB will canonicalize file names (e.g., expand symlinks)
2964 before comparing them. Canonicalization is an expensive operation,
2965 but it allows the same file be known by more than one base name.
2966 If not set (the default), all source files are assumed to have just
2967 one base name, and gdb will do file name comparisons more efficiently.
2973 Set a user name and notes for the current and any future trace runs.
2974 This is useful for long-running and/or disconnected traces, to
2975 inform others (or yourself) as to who is running the trace, supply
2976 contact information, or otherwise explain what is going on.
2978 set trace-stop-notes
2979 show trace-stop-notes
2980 Set a note attached to the trace run, that is displayed when the
2981 trace has been stopped by a tstop command. This is useful for
2982 instance as an explanation, if you are stopping a trace run that was
2983 started by someone else.
2985 * New remote packets
2989 Dynamically enable a tracepoint in a started trace experiment.
2993 Dynamically disable a tracepoint in a started trace experiment.
2997 Set the user and notes of the trace run.
3001 Query the current status of a tracepoint.
3005 Query the minimum length of instruction at which a fast tracepoint may
3008 * Dcache size (number of lines) and line-size are now runtime-configurable
3009 via "set dcache line" and "set dcache line-size" commands.
3013 Texas Instruments TMS320C6x tic6x-*-*
3017 Renesas RL78 rl78-*-elf
3019 *** Changes in GDB 7.3.1
3021 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3023 *** Changes in GDB 7.3
3025 * GDB has a new command: "thread find [REGEXP]".
3026 It finds the thread id whose name, target id, or thread extra info
3027 matches the given regular expression.
3029 * The "catch syscall" command now works on mips*-linux* targets.
3031 * The -data-disassemble MI command now supports modes 2 and 3 for
3032 dumping the instruction opcodes.
3034 * New command line options
3036 -data-directory DIR Specify DIR as the "data-directory".
3037 This is mostly for testing purposes.
3039 * The "maint set python auto-load on|off" command has been renamed to
3040 "set auto-load-scripts on|off".
3042 * GDB has a new command: "set directories".
3043 It is like the "dir" command except that it replaces the
3044 source path list instead of augmenting it.
3046 * GDB now understands thread names.
3048 On GNU/Linux, "info threads" will display the thread name as set by
3049 prctl or pthread_setname_np.
3051 There is also a new command, "thread name", which can be used to
3052 assign a name internally for GDB to display.
3055 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3056 has been integrated into GDB.
3060 ** The function gdb.Write now accepts an optional keyword 'stream'.
3061 This keyword, when provided, will direct the output to either
3062 stdout, stderr, or GDB's logging output.
3064 ** Parameters can now be be sub-classed in Python, and in particular
3065 you may implement the get_set_doc and get_show_doc functions.
3066 This improves how Parameter set/show documentation is processed
3067 and allows for more dynamic content.
3069 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3070 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3071 have an is_valid method.
3073 ** Breakpoints can now be sub-classed in Python, and in particular
3074 you may implement a 'stop' function that is executed each time
3075 the inferior reaches that breakpoint.
3077 ** New function gdb.lookup_global_symbol looks up a global symbol.
3079 ** GDB values in Python are now callable if the value represents a
3080 function. For example, if 'some_value' represents a function that
3081 takes two integer parameters and returns a value, you can call
3082 that function like so:
3084 result = some_value (10,20)
3086 ** Module gdb.types has been added.
3087 It contains a collection of utilities for working with gdb.Types objects:
3088 get_basic_type, has_field, make_enum_dict.
3090 ** Module gdb.printing has been added.
3091 It contains utilities for writing and registering pretty-printers.
3092 New classes: PrettyPrinter, SubPrettyPrinter,
3093 RegexpCollectionPrettyPrinter.
3094 New function: register_pretty_printer.
3096 ** New commands "info pretty-printers", "enable pretty-printer" and
3097 "disable pretty-printer" have been added.
3099 ** gdb.parameter("directories") is now available.
3101 ** New function gdb.newest_frame returns the newest frame in the
3104 ** The gdb.InferiorThread class has a new "name" attribute. This
3105 holds the thread's name.
3107 ** Python Support for Inferior events.
3108 Python scripts can add observers to be notified of events
3109 occurring in the process being debugged.
3110 The following events are currently supported:
3111 - gdb.events.cont Continue event.
3112 - gdb.events.exited Inferior exited event.
3113 - gdb.events.stop Signal received, and Breakpoint hit events.
3117 ** GDB now puts template parameters in scope when debugging in an
3118 instantiation. For example, if you have:
3120 template<int X> int func (void) { return X; }
3122 then if you step into func<5>, "print X" will show "5". This
3123 feature requires proper debuginfo support from the compiler; it
3124 was added to GCC 4.5.
3126 ** The motion commands "next", "finish", "until", and "advance" now
3127 work better when exceptions are thrown. In particular, GDB will
3128 no longer lose control of the inferior; instead, the GDB will
3129 stop the inferior at the point at which the exception is caught.
3130 This functionality requires a change in the exception handling
3131 code that was introduced in GCC 4.5.
3133 * GDB now follows GCC's rules on accessing volatile objects when
3134 reading or writing target state during expression evaluation.
3135 One notable difference to prior behavior is that "print x = 0"
3136 no longer generates a read of x; the value of the assignment is
3137 now always taken directly from the value being assigned.
3139 * GDB now has some support for using labels in the program's source in
3140 linespecs. For instance, you can use "advance label" to continue
3141 execution to a label.
3143 * GDB now has support for reading and writing a new .gdb_index
3144 section. This section holds a fast index of DWARF debugging
3145 information and can be used to greatly speed up GDB startup and
3146 operation. See the documentation for `save gdb-index' for details.
3148 * The "watch" command now accepts an optional "-location" argument.
3149 When used, this causes GDB to watch the memory referred to by the
3150 expression. Such a watchpoint is never deleted due to it going out
3153 * GDB now supports thread debugging of core dumps on GNU/Linux.
3155 GDB now activates thread debugging using the libthread_db library
3156 when debugging GNU/Linux core dumps, similarly to when debugging
3157 live processes. As a result, when debugging a core dump file, GDB
3158 is now able to display pthread_t ids of threads. For example, "info
3159 threads" shows the same output as when debugging the process when it
3160 was live. In earlier releases, you'd see something like this:
3163 * 1 LWP 6780 main () at main.c:10
3165 While now you see this:
3168 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3170 It is also now possible to inspect TLS variables when debugging core
3173 When debugging a core dump generated on a machine other than the one
3174 used to run GDB, you may need to point GDB at the correct
3175 libthread_db library with the "set libthread-db-search-path"
3176 command. See the user manual for more details on this command.
3178 * When natively debugging programs on PowerPC BookE processors running
3179 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3180 which stop execution of the inferior whenever it executes an instruction
3181 at any address within the specified range. See the "PowerPC Embedded"
3182 section in the user manual for more details.
3184 * New features in the GDB remote stub, GDBserver
3186 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3187 and i686 LynxOS (version 5.x).
3189 ** GDBserver is now supported on Blackfin Linux.
3191 * New native configurations
3193 ia64 HP-UX ia64-*-hpux*
3197 Analog Devices, Inc. Blackfin Processor bfin-*
3199 * Ada task switching is now supported on sparc-elf targets when
3200 debugging a program using the Ravenscar Profile. For more information,
3201 see the "Tasking Support when using the Ravenscar Profile" section
3202 in the GDB user manual.
3204 * Guile support was removed.
3206 * New features in the GNU simulator
3208 ** The --map-info flag lists all known core mappings.
3210 ** CFI flashes may be simulated via the "cfi" device.
3212 *** Changes in GDB 7.2
3214 * Shared library support for remote targets by default
3216 When GDB is configured for a generic, non-OS specific target, like
3217 for example, --target=arm-eabi or one of the many *-*-elf targets,
3218 GDB now queries remote stubs for loaded shared libraries using the
3219 `qXfer:libraries:read' packet. Previously, shared library support
3220 was always disabled for such configurations.
3224 ** Argument Dependent Lookup (ADL)
3226 In C++ ADL lookup directs function search to the namespaces of its
3227 arguments even if the namespace has not been imported.
3237 Here the compiler will search for `foo' in the namespace of 'b'
3238 and find A::foo. GDB now supports this. This construct is commonly
3239 used in the Standard Template Library for operators.
3241 ** Improved User Defined Operator Support
3243 In addition to member operators, GDB now supports lookup of operators
3244 defined in a namespace and imported with a `using' directive, operators
3245 defined in the global scope, operators imported implicitly from an
3246 anonymous namespace, and the ADL operators mentioned in the previous
3248 GDB now also supports proper overload resolution for all the previously
3249 mentioned flavors of operators.
3251 ** static const class members
3253 Printing of static const class members that are initialized in the
3254 class definition has been fixed.
3256 * Windows Thread Information Block access.
3258 On Windows targets, GDB now supports displaying the Windows Thread
3259 Information Block (TIB) structure. This structure is visible either
3260 by using the new command `info w32 thread-information-block' or, by
3261 dereferencing the new convenience variable named `$_tlb', a
3262 thread-specific pointer to the TIB. This feature is also supported
3263 when remote debugging using GDBserver.
3265 * Static tracepoints
3267 Static tracepoints are calls in the user program into a tracing
3268 library. One such library is a port of the LTTng kernel tracer to
3269 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3270 When debugging with GDBserver, GDB now supports combining the GDB
3271 tracepoint machinery with such libraries. For example: the user can
3272 use GDB to probe a static tracepoint marker (a call from the user
3273 program into the tracing library) with the new "strace" command (see
3274 "New commands" below). This creates a "static tracepoint" in the
3275 breakpoint list, that can be manipulated with the same feature set
3276 as fast and regular tracepoints. E.g., collect registers, local and
3277 global variables, collect trace state variables, and define
3278 tracepoint conditions. In addition, the user can collect extra
3279 static tracepoint marker specific data, by collecting the new
3280 $_sdata internal variable. When analyzing the trace buffer, you can
3281 inspect $_sdata like any other variable available to GDB. For more
3282 information, see the "Tracepoints" chapter in GDB user manual. New
3283 remote packets have been defined to support static tracepoints, see
3284 the "New remote packets" section below.
3286 * Better reconstruction of tracepoints after disconnected tracing
3288 GDB will attempt to download the original source form of tracepoint
3289 definitions when starting a trace run, and then will upload these
3290 upon reconnection to the target, resulting in a more accurate
3291 reconstruction of the tracepoints that are in use on the target.
3295 You can now exercise direct control over the ways that GDB can
3296 affect your program. For instance, you can disallow the setting of
3297 breakpoints, so that the program can run continuously (assuming
3298 non-stop mode). In addition, the "observer" variable is available
3299 to switch all of the different controls; in observer mode, GDB
3300 cannot affect the target's behavior at all, which is useful for
3301 tasks like diagnosing live systems in the field.
3303 * The new convenience variable $_thread holds the number of the
3306 * New remote packets
3310 Return the address of the Windows Thread Information Block of a given thread.
3314 In response to several of the tracepoint packets, the target may now
3315 also respond with a number of intermediate `qRelocInsn' request
3316 packets before the final result packet, to have GDB handle
3317 relocating an instruction to execute at a different address. This
3318 is particularly useful for stubs that support fast tracepoints. GDB
3319 reports support for this feature in the qSupported packet.
3323 List static tracepoint markers in the target program.
3327 List static tracepoint markers at a given address in the target
3330 qXfer:statictrace:read
3332 Read the static trace data collected (by a `collect $_sdata'
3333 tracepoint action). The remote stub reports support for this packet
3334 to gdb's qSupported query.
3338 Send the current settings of GDB's permission flags.
3342 Send part of the source (textual) form of a tracepoint definition,
3343 which includes location, conditional, and action list.
3345 * The source command now accepts a -s option to force searching for the
3346 script in the source search path even if the script name specifies
3349 * New features in the GDB remote stub, GDBserver
3351 - GDBserver now support tracepoints (including fast tracepoints, and
3352 static tracepoints). The feature is currently supported by the
3353 i386-linux and amd64-linux builds. See the "Tracepoints support
3354 in gdbserver" section in the manual for more information.
3356 GDBserver JIT compiles the tracepoint's conditional agent
3357 expression bytecode into native code whenever possible for low
3358 overhead dynamic tracepoints conditionals. For such tracepoints,
3359 an expression that examines program state is evaluated when the
3360 tracepoint is reached, in order to determine whether to capture
3361 trace data. If the condition is simple and false, processing the
3362 tracepoint finishes very quickly and no data is gathered.
3364 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3365 for static tracepoints support.
3367 - GDBserver now supports x86_64 Windows 64-bit debugging.
3369 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3370 it understands register description.
3372 * The --batch flag now disables pagination and queries.
3374 * X86 general purpose registers
3376 GDB now supports reading/writing byte, word and double-word x86
3377 general purpose registers directly. This means you can use, say,
3378 $ah or $ax to refer, respectively, to the byte register AH and
3379 16-bit word register AX that are actually portions of the 32-bit
3380 register EAX or 64-bit register RAX.
3382 * The `commands' command now accepts a range of breakpoints to modify.
3383 A plain `commands' following a command that creates multiple
3384 breakpoints affects all the breakpoints set by that command. This
3385 applies to breakpoints set by `rbreak', and also applies when a
3386 single `break' command creates multiple breakpoints (e.g.,
3387 breakpoints on overloaded c++ functions).
3389 * The `rbreak' command now accepts a filename specification as part of
3390 its argument, limiting the functions selected by the regex to those
3391 in the specified file.
3393 * Support for remote debugging Windows and SymbianOS shared libraries
3394 from Unix hosts has been improved. Non Windows GDB builds now can
3395 understand target reported file names that follow MS-DOS based file
3396 system semantics, such as file names that include drive letters and
3397 use the backslash character as directory separator. This makes it
3398 possible to transparently use the "set sysroot" and "set
3399 solib-search-path" on Unix hosts to point as host copies of the
3400 target's shared libraries. See the new command "set
3401 target-file-system-kind" described below, and the "Commands to
3402 specify files" section in the user manual for more information.
3406 eval template, expressions...
3407 Convert the values of one or more expressions under the control
3408 of the string template to a command line, and call it.
3410 set target-file-system-kind unix|dos-based|auto
3411 show target-file-system-kind
3412 Set or show the assumed file system kind for target reported file
3415 save breakpoints <filename>
3416 Save all current breakpoint definitions to a file suitable for use
3417 in a later debugging session. To read the saved breakpoint
3418 definitions, use the `source' command.
3420 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3423 info static-tracepoint-markers
3424 Display information about static tracepoint markers in the target.
3426 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3427 Define a static tracepoint by probing a marker at the given
3428 function, line, address, or marker ID.
3432 Enable and disable observer mode.
3434 set may-write-registers on|off
3435 set may-write-memory on|off
3436 set may-insert-breakpoints on|off
3437 set may-insert-tracepoints on|off
3438 set may-insert-fast-tracepoints on|off
3439 set may-interrupt on|off
3440 Set individual permissions for GDB effects on the target. Note that
3441 some of these settings can have undesirable or surprising
3442 consequences, particularly when changed in the middle of a session.
3443 For instance, disabling the writing of memory can prevent
3444 breakpoints from being inserted, cause single-stepping to fail, or
3445 even crash your program, if you disable after breakpoints have been
3446 inserted. However, GDB should not crash.
3448 set record memory-query on|off
3449 show record memory-query
3450 Control whether to stop the inferior if memory changes caused
3451 by an instruction cannot be recorded.
3456 The disassemble command now supports "start,+length" form of two arguments.
3460 ** GDB now provides a new directory location, called the python directory,
3461 where Python scripts written for GDB can be installed. The location
3462 of that directory is <data-directory>/python, where <data-directory>
3463 is the GDB data directory. For more details, see section `Scripting
3464 GDB using Python' in the manual.
3466 ** The GDB Python API now has access to breakpoints, symbols, symbol
3467 tables, program spaces, inferiors, threads and frame's code blocks.
3468 Additionally, GDB Parameters can now be created from the API, and
3469 manipulated via set/show in the CLI.
3471 ** New functions gdb.target_charset, gdb.target_wide_charset,
3472 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3474 ** New exception gdb.GdbError.
3476 ** Pretty-printers are now also looked up in the current program space.
3478 ** Pretty-printers can now be individually enabled and disabled.
3480 ** GDB now looks for names of Python scripts to auto-load in a
3481 special section named `.debug_gdb_scripts', in addition to looking
3482 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3484 * Tracepoint actions were unified with breakpoint commands. In particular,
3485 there are no longer differences in "info break" output for breakpoints and
3486 tracepoints and the "commands" command can be used for both tracepoints and
3487 regular breakpoints.
3491 ARM Symbian arm*-*-symbianelf*
3493 * D language support.
3494 GDB now supports debugging programs written in the D programming
3497 * GDB now supports the extended ptrace interface for PowerPC which is
3498 available since Linux kernel version 2.6.34. This automatically enables
3499 any hardware breakpoints and additional hardware watchpoints available in
3500 the processor. The old ptrace interface exposes just one hardware
3501 watchpoint and no hardware breakpoints.
3503 * GDB is now able to use the Data Value Compare (DVC) register available on
3504 embedded PowerPC processors to implement in hardware simple watchpoint
3505 conditions of the form:
3507 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3509 This works in native GDB running on Linux kernels with the extended ptrace
3510 interface mentioned above.
3512 *** Changes in GDB 7.1
3516 ** Namespace Support
3518 GDB now supports importing of namespaces in C++. This enables the
3519 user to inspect variables from imported namespaces. Support for
3520 namepace aliasing has also been added. So, if a namespace is
3521 aliased in the current scope (e.g. namepace C=A; ) the user can
3522 print variables using the alias (e.g. (gdb) print C::x).
3526 All known bugs relating to the printing of virtual base class were
3527 fixed. It is now possible to call overloaded static methods using a
3532 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3533 and reinterpret_cast<> are now handled by the C++ expression parser.
3537 Xilinx MicroBlaze microblaze-*-*
3542 Xilinx MicroBlaze microblaze
3545 * Multi-program debugging.
3547 GDB now has support for multi-program (a.k.a. multi-executable or
3548 multi-exec) debugging. This allows for debugging multiple inferiors
3549 simultaneously each running a different program under the same GDB
3550 session. See "Debugging Multiple Inferiors and Programs" in the
3551 manual for more information. This implied some user visible changes
3552 in the multi-inferior support. For example, "info inferiors" now
3553 lists inferiors that are not running yet or that have exited
3554 already. See also "New commands" and "New options" below.
3556 * New tracing features
3558 GDB's tracepoint facility now includes several new features:
3560 ** Trace state variables
3562 GDB tracepoints now include support for trace state variables, which
3563 are variables managed by the target agent during a tracing
3564 experiment. They are useful for tracepoints that trigger each
3565 other, so for instance one tracepoint can count hits in a variable,
3566 and then a second tracepoint has a condition that is true when the
3567 count reaches a particular value. Trace state variables share the
3568 $-syntax of GDB convenience variables, and can appear in both
3569 tracepoint actions and condition expressions. Use the "tvariable"
3570 command to create, and "info tvariables" to view; see "Trace State
3571 Variables" in the manual for more detail.
3575 GDB now includes an option for defining fast tracepoints, which
3576 targets may implement more efficiently, such as by installing a jump
3577 into the target agent rather than a trap instruction. The resulting
3578 speedup can be by two orders of magnitude or more, although the
3579 tradeoff is that some program locations on some target architectures
3580 might not allow fast tracepoint installation, for instance if the
3581 instruction to be replaced is shorter than the jump. To request a
3582 fast tracepoint, use the "ftrace" command, with syntax identical to
3583 the regular trace command.
3585 ** Disconnected tracing
3587 It is now possible to detach GDB from the target while it is running
3588 a trace experiment, then reconnect later to see how the experiment
3589 is going. In addition, a new variable disconnected-tracing lets you
3590 tell the target agent whether to continue running a trace if the
3591 connection is lost unexpectedly.
3595 GDB now has the ability to save the trace buffer into a file, and
3596 then use that file as a target, similarly to you can do with
3597 corefiles. You can select trace frames, print data that was
3598 collected in them, and use tstatus to display the state of the
3599 tracing run at the moment that it was saved. To create a trace
3600 file, use "tsave <filename>", and to use it, do "target tfile
3603 ** Circular trace buffer
3605 You can ask the target agent to handle the trace buffer as a
3606 circular buffer, discarding the oldest trace frames to make room for
3607 newer ones, by setting circular-trace-buffer to on. This feature may
3608 not be available for all target agents.
3613 The disassemble command, when invoked with two arguments, now requires
3614 the arguments to be comma-separated.
3617 The info variables command now displays variable definitions. Files
3618 which only declare a variable are not shown.
3621 The source command is now capable of sourcing Python scripts.
3622 This feature is dependent on the debugger being build with Python
3625 Related to this enhancement is also the introduction of a new command
3626 "set script-extension" (see below).
3628 * New commands (for set/show, see "New options" below)
3630 record save [<FILENAME>]
3631 Save a file (in core file format) containing the process record
3632 execution log for replay debugging at a later time.
3634 record restore <FILENAME>
3635 Restore the process record execution log that was saved at an
3636 earlier time, for replay debugging.
3638 add-inferior [-copies <N>] [-exec <FILENAME>]
3641 clone-inferior [-copies <N>] [ID]
3642 Make a new inferior ready to execute the same program another
3643 inferior has loaded.
3648 maint info program-spaces
3649 List the program spaces loaded into GDB.
3651 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3652 show remote interrupt-sequence
3653 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3654 as the sequence to the remote target in order to interrupt the execution.
3655 Ctrl-C is a default. Some system prefers BREAK which is high level of
3656 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3657 Magic SysRq g. It is BREAK signal and character 'g'.
3659 set remote interrupt-on-connect [on | off]
3660 show remote interrupt-on-connect
3661 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3662 remote target when gdb connects to it. This is needed when you debug
3665 set remotebreak [on | off]
3667 Deprecated. Use "set/show remote interrupt-sequence" instead.
3669 tvariable $NAME [ = EXP ]
3670 Create or modify a trace state variable.
3673 List trace state variables and their values.
3675 delete tvariable $NAME ...
3676 Delete one or more trace state variables.
3679 Evaluate the given expressions without collecting anything into the
3680 trace buffer. (Valid in tracepoint actions only.)
3682 ftrace FN / FILE:LINE / *ADDR
3683 Define a fast tracepoint at the given function, line, or address.
3685 * New expression syntax
3687 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3688 GDB now parses 0b101010 identically with 42.
3692 set follow-exec-mode new|same
3693 show follow-exec-mode
3694 Control whether GDB reuses the same inferior across an exec call or
3695 creates a new one. This is useful to be able to restart the old
3696 executable after the inferior having done an exec call.
3698 set default-collect EXPR, ...
3699 show default-collect
3700 Define a list of expressions to be collected at each tracepoint.
3701 This is a useful way to ensure essential items are not overlooked,
3702 such as registers or a critical global variable.
3704 set disconnected-tracing
3705 show disconnected-tracing
3706 If set to 1, the target is instructed to continue tracing if it
3707 loses its connection to GDB. If 0, the target is to stop tracing
3710 set circular-trace-buffer
3711 show circular-trace-buffer
3712 If set to on, the target is instructed to use a circular trace buffer
3713 and discard the oldest trace frames instead of stopping the trace due
3714 to a full trace buffer. If set to off, the trace stops when the buffer
3715 fills up. Some targets may not support this.
3717 set script-extension off|soft|strict
3718 show script-extension
3719 If set to "off", the debugger does not perform any script language
3720 recognition, and all sourced files are assumed to be GDB scripts.
3721 If set to "soft" (the default), files are sourced according to
3722 filename extension, falling back to GDB scripts if the first
3724 If set to "strict", files are sourced according to filename extension.
3726 set ada trust-PAD-over-XVS on|off
3727 show ada trust-PAD-over-XVS
3728 If off, activate a workaround against a bug in the debugging information
3729 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3730 the GCC sources for more information about the GNAT encoding and
3731 PAD types in particular). It is always safe to set this option to
3732 off, but this introduces a slight performance penalty. The default
3735 * Python API Improvements
3737 ** GDB provides the new class gdb.LazyString. This is useful in
3738 some pretty-printing cases. The new method gdb.Value.lazy_string
3739 provides a simple way to create objects of this type.
3741 ** The fields returned by gdb.Type.fields now have an
3742 `is_base_class' attribute.
3744 ** The new method gdb.Type.range returns the range of an array type.
3746 ** The new method gdb.parse_and_eval can be used to parse and
3747 evaluate an expression.
3749 * New remote packets
3752 Define a trace state variable.
3755 Get the current value of a trace state variable.
3758 Set desired tracing behavior upon disconnection.
3761 Set the trace buffer to be linear or circular.
3764 Get data about the tracepoints currently in use.
3768 Process record now works correctly with hardware watchpoints.
3770 Multiple bug fixes have been made to the mips-irix port, making it
3771 much more reliable. In particular:
3772 - Debugging threaded applications is now possible again. Previously,
3773 GDB would hang while starting the program, or while waiting for
3774 the program to stop at a breakpoint.
3775 - Attaching to a running process no longer hangs.
3776 - An error occurring while loading a core file has been fixed.
3777 - Changing the value of the PC register now works again. This fixes
3778 problems observed when using the "jump" command, or when calling
3779 a function from GDB, or even when assigning a new value to $pc.
3780 - With the "finish" and "return" commands, the return value for functions
3781 returning a small array is now correctly printed.
3782 - It is now possible to break on shared library code which gets executed
3783 during a shared library init phase (code executed while executing
3784 their .init section). Previously, the breakpoint would have no effect.
3785 - GDB is now able to backtrace through the signal handler for
3786 non-threaded programs.
3788 PIE (Position Independent Executable) programs debugging is now supported.
3789 This includes debugging execution of PIC (Position Independent Code) shared
3790 libraries although for that, it should be possible to run such libraries as an
3793 *** Changes in GDB 7.0
3795 * GDB now has an interface for JIT compilation. Applications that
3796 dynamically generate code can create symbol files in memory and register
3797 them with GDB. For users, the feature should work transparently, and
3798 for JIT developers, the interface is documented in the GDB manual in the
3799 "JIT Compilation Interface" chapter.
3801 * Tracepoints may now be conditional. The syntax is as for
3802 breakpoints; either an "if" clause appended to the "trace" command,
3803 or the "condition" command is available. GDB sends the condition to
3804 the target for evaluation using the same bytecode format as is used
3805 for tracepoint actions.
3807 * The disassemble command now supports: an optional /r modifier, print the
3808 raw instructions in hex as well as in symbolic form, and an optional /m
3809 modifier to print mixed source+assembly.
3811 * Process record and replay
3813 In a architecture environment that supports ``process record and
3814 replay'', ``process record and replay'' target can record a log of
3815 the process execution, and replay it with both forward and reverse
3818 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3819 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3820 set execution-direction {forward|reverse}, for targets that support
3823 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3824 feature is available with a native GDB running on kernel version
3827 * GDB now has support for multi-byte and wide character sets on the
3828 target. Strings whose character type is wchar_t, char16_t, or
3829 char32_t are now correctly printed. GDB supports wide- and unicode-
3830 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3831 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3832 `printf'. This feature requires iconv to work properly; if your
3833 system does not have a working iconv, GDB can use GNU libiconv. See
3834 the installation instructions for more information.
3836 * GDB now supports automatic retrieval of shared library files from
3837 remote targets. To use this feature, specify a system root that begins
3838 with the `remote:' prefix, either via the `set sysroot' command or via
3839 the `--with-sysroot' configure-time option.
3841 * "info sharedlibrary" now takes an optional regex of libraries to show,
3842 and it now reports if a shared library has no debugging information.
3844 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3845 now complete on file names.
3847 * When completing in expressions, gdb will attempt to limit
3848 completions to allowable structure or union fields, where appropriate.
3849 For instance, consider:
3851 # struct example { int f1; double f2; };
3852 # struct example variable;
3855 If the user types TAB at the end of this command line, the available
3856 completions will be "f1" and "f2".
3858 * Inlined functions are now supported. They show up in backtraces, and
3859 the "step", "next", and "finish" commands handle them automatically.
3861 * GDB now supports the token-splicing (##) and stringification (#)
3862 operators when expanding macros. It also supports variable-arity
3865 * GDB now supports inspecting extra signal information, exported by
3866 the new $_siginfo convenience variable. The feature is currently
3867 implemented on linux ARM, i386 and amd64.
3869 * GDB can now display the VFP floating point registers and NEON vector
3870 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3871 can provide these registers (requires Linux 2.6.30 or later). Remote
3872 and simulator targets may also provide them.
3874 * New remote packets
3877 Search memory for a sequence of bytes.
3880 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3881 operation over reliable transport links. Use of this packet is
3882 controlled by the `set remote noack-packet' command.
3885 Kill the process with the specified process ID. Use this in preference
3886 to `k' when multiprocess protocol extensions are supported.
3889 Obtains additional operating system information
3893 Read or write additional signal information.
3895 * Removed remote protocol undocumented extension
3897 An undocumented extension to the remote protocol's `S' stop reply
3898 packet that permited the stub to pass a process id was removed.
3899 Remote servers should use the `T' stop reply packet instead.
3901 * GDB now supports multiple function calling conventions according to the
3902 DWARF-2 DW_AT_calling_convention function attribute.
3904 * The SH target utilizes the aforementioned change to distinguish between gcc
3905 and Renesas calling convention. It also adds the new CLI commands
3906 `set/show sh calling-convention'.
3908 * GDB can now read compressed debug sections, as produced by GNU gold
3909 with the --compress-debug-sections=zlib flag.
3911 * 64-bit core files are now supported on AIX.
3913 * Thread switching is now supported on Tru64.
3915 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3916 which will be allocated using malloc later in program execution.
3918 * The qXfer:libraries:read remote procotol packet now allows passing a
3919 list of section offsets.
3921 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3922 conditions handling signals delivered during attach or thread creation
3923 have also been fixed.
3925 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3926 From the user's standpoint, all unqualified instances of True and False
3927 are treated as the standard definitions, regardless of context.
3929 * GDB now parses C++ symbol and type names more flexibly. For
3932 template<typename T> class C { };
3935 GDB will now correctly handle all of:
3937 ptype C<char const *>
3938 ptype C<char const*>
3939 ptype C<const char *>
3940 ptype C<const char*>
3942 * New features in the GDB remote stub, gdbserver
3944 - The "--wrapper" command-line argument tells gdbserver to use a
3945 wrapper program to launch programs for debugging.
3947 - On PowerPC and S/390 targets, it is now possible to use a single
3948 gdbserver executable to debug both 32-bit and 64-bit programs.
3949 (This requires gdbserver itself to be built as a 64-bit executable.)
3951 - gdbserver uses the new noack protocol mode for TCP connections to
3952 reduce communications latency, if also supported and enabled in GDB.
3954 - Support for the sparc64-linux-gnu target is now included in
3957 - The amd64-linux build of gdbserver now supports debugging both
3958 32-bit and 64-bit programs.
3960 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3961 now support hardware watchpoints, and will use them automatically
3966 GDB now has support for scripting using Python. Whether this is
3967 available is determined at configure time.
3969 New GDB commands can now be written in Python.
3971 * Ada tasking support
3973 Ada tasks can now be inspected in GDB. The following commands have
3977 Print the list of Ada tasks.
3979 Print detailed information about task number N.
3981 Print the task number of the current task.
3983 Switch the context of debugging to task number N.
3985 * Support for user-defined prefixed commands. The "define" command can
3986 add new commands to existing prefixes, e.g. "target".
3988 * Multi-inferior, multi-process debugging.
3990 GDB now has generalized support for multi-inferior debugging. See
3991 "Debugging Multiple Inferiors" in the manual for more information.
3992 Although availability still depends on target support, the command
3993 set is more uniform now. The GNU/Linux specific multi-forks support
3994 has been migrated to this new framework. This implied some user
3995 visible changes; see "New commands" and also "Removed commands"
3998 * Target descriptions can now describe the target OS ABI. See the
3999 "Target Description Format" section in the user manual for more
4002 * Target descriptions can now describe "compatible" architectures
4003 to indicate that the target can execute applications for a different
4004 architecture in addition to those for the main target architecture.
4005 See the "Target Description Format" section in the user manual for
4008 * Multi-architecture debugging.
4010 GDB now includes general supports for debugging applications on
4011 hybrid systems that use more than one single processor architecture
4012 at the same time. Each such hybrid architecture still requires
4013 specific support to be added. The only hybrid architecture supported
4014 in this version of GDB is the Cell Broadband Engine.
4016 * GDB now supports integrated debugging of Cell/B.E. applications that
4017 use both the PPU and SPU architectures. To enable support for hybrid
4018 Cell/B.E. debugging, you need to configure GDB to support both the
4019 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4020 --enable-targets configure option.
4022 * Non-stop mode debugging.
4024 For some targets, GDB now supports an optional mode of operation in
4025 which you can examine stopped threads while other threads continue
4026 to execute freely. This is referred to as non-stop mode, with the
4027 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4028 section in the user manual for more information.
4030 To be able to support remote non-stop debugging, a remote stub needs
4031 to implement the non-stop mode remote protocol extensions, as
4032 described in the "Remote Non-Stop" section of the user manual. The
4033 GDB remote stub, gdbserver, has been adjusted to support these
4034 extensions on linux targets.
4036 * New commands (for set/show, see "New options" below)
4038 catch syscall [NAME(S) | NUMBER(S)]
4039 Catch system calls. Arguments, which should be names of system
4040 calls or their numbers, mean catch only those syscalls. Without
4041 arguments, every syscall will be caught. When the inferior issues
4042 any of the specified syscalls, GDB will stop and announce the system
4043 call, both when it is called and when its call returns. This
4044 feature is currently available with a native GDB running on the
4045 Linux Kernel, under the following architectures: x86, x86_64,
4046 PowerPC and PowerPC64.
4048 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4050 Search memory for a sequence of bytes.
4052 maint set python print-stack
4053 maint show python print-stack
4054 Show a stack trace when an error is encountered in a Python script.
4057 Invoke CODE by passing it to the Python interpreter.
4062 These allow macros to be defined, undefined, and listed
4066 Show operating system information about processes.
4069 List the inferiors currently under GDB's control.
4072 Switch focus to inferior number NUM.
4075 Detach from inferior number NUM.
4078 Kill inferior number NUM.
4082 set spu stop-on-load
4083 show spu stop-on-load
4084 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4086 set spu auto-flush-cache
4087 show spu auto-flush-cache
4088 Control whether to automatically flush the software-managed cache
4089 during Cell/B.E. debugging.
4091 set sh calling-convention
4092 show sh calling-convention
4093 Control the calling convention used when calling SH target functions.
4096 show debug timestamp
4097 Control display of timestamps with GDB debugging output.
4099 set disassemble-next-line
4100 show disassemble-next-line
4101 Control display of disassembled source lines or instructions when
4104 set remote noack-packet
4105 show remote noack-packet
4106 Set/show the use of remote protocol QStartNoAckMode packet. See above
4107 under "New remote packets."
4109 set remote query-attached-packet
4110 show remote query-attached-packet
4111 Control use of remote protocol `qAttached' (query-attached) packet.
4113 set remote read-siginfo-object
4114 show remote read-siginfo-object
4115 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4118 set remote write-siginfo-object
4119 show remote write-siginfo-object
4120 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4123 set remote reverse-continue
4124 show remote reverse-continue
4125 Control use of remote protocol 'bc' (reverse-continue) packet.
4127 set remote reverse-step
4128 show remote reverse-step
4129 Control use of remote protocol 'bs' (reverse-step) packet.
4131 set displaced-stepping
4132 show displaced-stepping
4133 Control displaced stepping mode. Displaced stepping is a way to
4134 single-step over breakpoints without removing them from the debuggee.
4135 Also known as "out-of-line single-stepping".
4138 show debug displaced
4139 Control display of debugging info for displaced stepping.
4141 maint set internal-error
4142 maint show internal-error
4143 Control what GDB does when an internal error is detected.
4145 maint set internal-warning
4146 maint show internal-warning
4147 Control what GDB does when an internal warning is detected.
4152 Use a wrapper program to launch programs for debugging.
4154 set multiple-symbols (all|ask|cancel)
4155 show multiple-symbols
4156 The value of this variable can be changed to adjust the debugger behavior
4157 when an expression or a breakpoint location contains an ambiguous symbol
4158 name (an overloaded function name, for instance).
4160 set breakpoint always-inserted
4161 show breakpoint always-inserted
4162 Keep breakpoints always inserted in the target, as opposed to inserting
4163 them when resuming the target, and removing them when the target stops.
4164 This option can improve debugger performance on slow remote targets.
4166 set arm fallback-mode (arm|thumb|auto)
4167 show arm fallback-mode
4168 set arm force-mode (arm|thumb|auto)
4170 These commands control how ARM GDB determines whether instructions
4171 are ARM or Thumb. The default for both settings is auto, which uses
4172 the current CPSR value for instructions without symbols; previous
4173 versions of GDB behaved as if "set arm fallback-mode arm".
4175 set disable-randomization
4176 show disable-randomization
4177 Standalone programs run with the virtual address space randomization enabled
4178 by default on some platforms. This option keeps the addresses stable across
4179 multiple debugging sessions.
4183 Control whether other threads are stopped or not when some thread hits
4188 Requests that asynchronous execution is enabled in the target, if available.
4189 In this case, it's possible to resume target in the background, and interact
4190 with GDB while the target is running. "show target-async" displays the
4191 current state of asynchronous execution of the target.
4193 set target-wide-charset
4194 show target-wide-charset
4195 The target-wide-charset is the name of the character set that GDB
4196 uses when printing characters whose type is wchar_t.
4198 set tcp auto-retry (on|off)
4200 set tcp connect-timeout
4201 show tcp connect-timeout
4202 These commands allow GDB to retry failed TCP connections to a remote stub
4203 with a specified timeout period; this is useful if the stub is launched
4204 in parallel with GDB but may not be ready to accept connections immediately.
4206 set libthread-db-search-path
4207 show libthread-db-search-path
4208 Control list of directories which GDB will search for appropriate
4211 set schedule-multiple (on|off)
4212 show schedule-multiple
4213 Allow GDB to resume all threads of all processes or only threads of
4214 the current process.
4218 Use more aggressive caching for accesses to the stack. This improves
4219 performance of remote debugging (particularly backtraces) without
4220 affecting correctness.
4222 set interactive-mode (on|off|auto)
4223 show interactive-mode
4224 Control whether GDB runs in interactive mode (on) or not (off).
4225 When in interactive mode, GDB waits for the user to answer all
4226 queries. Otherwise, GDB does not wait and assumes the default
4227 answer. When set to auto (the default), GDB determines which
4228 mode to use based on the stdin settings.
4233 For program forks, this is replaced by the new more generic `info
4234 inferiors' command. To list checkpoints, you can still use the
4235 `info checkpoints' command, which was an alias for the `info forks'
4239 Replaced by the new `inferior' command. To switch between
4240 checkpoints, you can still use the `restart' command, which was an
4241 alias for the `fork' command.
4244 This is removed, since some targets don't have a notion of
4245 processes. To switch between processes, you can still use the
4246 `inferior' command using GDB's own inferior number.
4249 For program forks, this is replaced by the new more generic `kill
4250 inferior' command. To delete a checkpoint, you can still use the
4251 `delete checkpoint' command, which was an alias for the `delete
4255 For program forks, this is replaced by the new more generic `detach
4256 inferior' command. To detach a checkpoint, you can still use the
4257 `detach checkpoint' command, which was an alias for the `detach
4260 * New native configurations
4262 x86/x86_64 Darwin i[34567]86-*-darwin*
4264 x86_64 MinGW x86_64-*-mingw*
4268 Lattice Mico32 lm32-*
4269 x86 DICOS i[34567]86-*-dicos*
4270 x86_64 DICOS x86_64-*-dicos*
4273 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4274 (mingw32ce) debugging.
4280 These commands were actually not implemented on any target.
4282 *** Changes in GDB 6.8
4284 * New native configurations
4286 NetBSD/hppa hppa*-*netbsd*
4287 Xtensa GNU/Linux xtensa*-*-linux*
4291 NetBSD/hppa hppa*-*-netbsd*
4292 Xtensa GNU/Lunux xtensa*-*-linux*
4294 * Change in command line behavior -- corefiles vs. process ids.
4296 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4297 attaching to process NUMBER fails, GDB no longer attempts to open a
4298 core file named NUMBER. Attaching to a program using the -c option
4299 is no longer supported. Instead, use the '-p' or '--pid' options.
4301 * GDB can now be built as a native debugger for debugging Windows x86
4302 (mingw32) Portable Executable (PE) programs.
4304 * Pending breakpoints no longer change their number when their address
4307 * GDB now supports breakpoints with multiple locations,
4308 including breakpoints on C++ constructors, inside C++ templates,
4309 and in inlined functions.
4311 * GDB's ability to debug optimized code has been improved. GDB more
4312 accurately identifies function bodies and lexical blocks that occupy
4313 more than one contiguous range of addresses.
4315 * Target descriptions can now describe registers for PowerPC.
4317 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4318 registers on PowerPC targets.
4320 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4321 targets even when the libthread_db library is not available.
4323 * The GDB remote stub, gdbserver, now supports the new file transfer
4324 commands (remote put, remote get, and remote delete).
4326 * The GDB remote stub, gdbserver, now supports run and attach in
4327 extended-remote mode.
4329 * hppa*64*-*-hpux11* target broken
4330 The debugger is unable to start a program and fails with the following
4331 error: "Error trying to get information about dynamic linker".
4332 The gdb-6.7 release is also affected.
4334 * GDB now supports the --enable-targets= configure option to allow
4335 building a single GDB executable that supports multiple remote
4336 target architectures.
4338 * GDB now supports debugging C and C++ programs which use the
4339 Decimal Floating Point extension. In addition, the PowerPC target
4340 now has a set of pseudo-registers to inspect decimal float values
4341 stored in two consecutive float registers.
4343 * The -break-insert MI command can optionally create pending
4346 * Improved support for debugging Ada
4347 Many improvements to the Ada language support have been made. These
4349 - Better support for Ada2005 interface types
4350 - Improved handling of arrays and slices in general
4351 - Better support for Taft-amendment types
4352 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4354 - Improved command completion in Ada
4357 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4362 set print frame-arguments (all|scalars|none)
4363 show print frame-arguments
4364 The value of this variable can be changed to control which argument
4365 values should be printed by the debugger when displaying a frame.
4370 Transfer files to and from a remote target, and delete remote files.
4377 Transfer files to and from a remote target, and delete remote files.
4379 * New remote packets
4386 Open, close, read, write, and delete files on the remote system.
4389 Attach to an existing process on the remote system, in extended-remote
4393 Run a new process on the remote system, in extended-remote mode.
4395 *** Changes in GDB 6.7
4397 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4398 bfd, libiberty and opcodes, as revealed by static analysis donated by
4399 Coverity, Inc. (http://scan.coverity.com).
4401 * When looking up multiply-defined global symbols, GDB will now prefer the
4402 symbol definition in the current shared library if it was built using the
4403 -Bsymbolic linker option.
4405 * When the Text User Interface (TUI) is not configured, GDB will now
4406 recognize the -tui command-line option and print a message that the TUI
4409 * The GDB remote stub, gdbserver, now has lower overhead for high
4410 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4412 * GDB for MIPS targets now autodetects whether a remote target provides
4413 32-bit or 64-bit register values.
4415 * Support for C++ member pointers has been improved.
4417 * GDB now understands XML target descriptions, which specify the
4418 target's overall architecture. GDB can read a description from
4419 a local file or over the remote serial protocol.
4421 * Vectors of single-byte data use a new integer type which is not
4422 automatically displayed as character or string data.
4424 * The /s format now works with the print command. It displays
4425 arrays of single-byte integers and pointers to single-byte integers
4428 * Target descriptions can now describe target-specific registers,
4429 for architectures which have implemented the support (currently
4430 only ARM, M68K, and MIPS).
4432 * GDB and the GDB remote stub, gdbserver, now support the XScale
4435 * The GDB remote stub, gdbserver, has been updated to support
4436 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4437 has been rewritten to use the standard GDB remote protocol.
4439 * GDB can now step into C++ functions which are called through thunks.
4441 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4443 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4444 layout. It also supports a TextSeg= and DataSeg= response when only
4445 segment base addresses (rather than offsets) are available.
4447 * The /i format now outputs any trailing branch delay slot instructions
4448 immediately following the last instruction within the count specified.
4450 * The GDB remote protocol "T" stop reply packet now supports a
4451 "library" response. Combined with the new "qXfer:libraries:read"
4452 packet, this response allows GDB to debug shared libraries on targets
4453 where the operating system manages the list of loaded libraries (e.g.
4454 Windows and SymbianOS).
4456 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4457 (DLLs) on Windows and Windows CE targets.
4459 * GDB now supports a faster verification that a .debug file matches its binary
4460 according to its build-id signature, if the signature is present.
4466 Enable or disable hardware flow control (RTS/CTS) on the serial port
4467 when debugging using remote targets.
4469 set mem inaccessible-by-default
4470 show mem inaccessible-by-default
4471 If the target supplies a memory map, for instance via the remote
4472 protocol's "qXfer:memory-map:read" packet, setting this variable
4473 prevents GDB from accessing memory outside the memory map. This
4474 is useful for targets with memory mapped registers or which react
4475 badly to accesses of unmapped address space.
4477 set breakpoint auto-hw
4478 show breakpoint auto-hw
4479 If the target supplies a memory map, for instance via the remote
4480 protocol's "qXfer:memory-map:read" packet, setting this variable
4481 lets GDB use hardware breakpoints automatically for memory regions
4482 where it can not use software breakpoints. This covers both the
4483 "break" command and internal breakpoints used for other commands
4484 including "next" and "finish".
4487 catch exception unhandled
4488 Stop the program execution when Ada exceptions are raised.
4491 Stop the program execution when an Ada assertion failed.
4495 Set an alternate system root for target files. This is a more
4496 general version of "set solib-absolute-prefix", which is now
4497 an alias to "set sysroot".
4500 Provide extended SPU facility status information. This set of
4501 commands is available only when debugging the Cell/B.E. SPU
4504 * New native configurations
4506 OpenBSD/sh sh*-*openbsd*
4509 unset tdesc filename
4511 Use the specified local file as an XML target description, and do
4512 not query the target for its built-in description.
4516 OpenBSD/sh sh*-*-openbsd*
4517 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4518 Toshiba Media Processor mep-elf
4520 * New remote packets
4523 Ignore the specified signals; pass them directly to the debugged program
4524 without stopping other threads or reporting them to GDB.
4526 qXfer:features:read:
4527 Read an XML target description from the target, which describes its
4532 Read or write contents of an spufs file on the target system. These
4533 packets are available only on the Cell/B.E. SPU architecture.
4535 qXfer:libraries:read:
4536 Report the loaded shared libraries. Combined with new "T" packet
4537 response, this packet allows GDB to debug shared libraries on
4538 targets where the operating system manages the list of loaded
4539 libraries (e.g. Windows and SymbianOS).
4543 Support for these obsolete configurations has been removed.
4551 i[34567]86-*-lynxos*
4552 i[34567]86-*-netware*
4553 i[34567]86-*-sco3.2v5*
4554 i[34567]86-*-sco3.2v4*
4556 i[34567]86-*-sysv4.2*
4559 i[34567]86-*-unixware2*
4560 i[34567]86-*-unixware*
4569 * Other removed features
4576 Various m68k-only ROM monitors.
4583 Various Renesas ROM monitors and debugging interfaces for SH and
4588 Support for a Macraigor serial interface to on-chip debugging.
4589 GDB does not directly support the newer parallel or USB
4594 A debug information format. The predecessor to DWARF 2 and
4595 DWARF 3, which are still supported.
4597 Support for the HP aCC compiler on HP-UX/PA-RISC
4599 SOM-encapsulated symbolic debugging information, automatic
4600 invocation of pxdb, and the aCC custom C++ ABI. This does not
4601 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4602 with aCC can still be debugged on an assembly level.
4604 MIPS ".pdr" sections
4606 A MIPS-specific format used to describe stack frame layout
4607 in debugging information.
4611 GDB could work with an older version of Guile to debug
4612 the interpreter and Scheme programs running in it.
4614 set mips stack-arg-size
4615 set mips saved-gpreg-size
4617 Use "set mips abi" to control parameter passing for MIPS.
4619 *** Changes in GDB 6.6
4624 Cell Broadband Engine SPU spu-elf
4626 * GDB can now be configured as a cross-debugger targeting native Windows
4627 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4628 running on a Windows system over TCP/IP to debug Windows programs.
4630 * The GDB remote stub, gdbserver, has been updated to support Windows and
4631 Cygwin debugging. Both single-threaded and multi-threaded programs are
4634 * The "set trust-readonly-sections" command works again. This command was
4635 broken in GDB 6.3, 6.4, and 6.5.
4637 * The "load" command now supports writing to flash memory, if the remote
4638 stub provides the required support.
4640 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4641 longer requires symbolic debug information (e.g. DWARF-2).
4646 unset substitute-path
4647 show substitute-path
4648 Manage a list of substitution rules that GDB uses to rewrite the name
4649 of the directories where the sources are located. This can be useful
4650 for instance when the sources were moved to a different location
4651 between compilation and debugging.
4655 Print each CLI command as it is executed. Each command is prefixed with
4656 a number of `+' symbols representing the nesting depth.
4657 The source command now has a `-v' option to enable the same feature.
4661 The ARM Demon monitor support (RDP protocol, "target rdp").
4663 Kernel Object Display, an embedded debugging feature which only worked with
4664 an obsolete version of Cisco IOS.
4666 The 'set download-write-size' and 'show download-write-size' commands.
4668 * New remote packets
4671 Tell a stub about GDB client features, and request remote target features.
4672 The first feature implemented is PacketSize, which allows the target to
4673 specify the size of packets it can handle - to minimize the number of
4674 packets required and improve performance when connected to a remote
4678 Fetch an OS auxilliary vector from the remote stub. This packet is a
4679 more efficient replacement for qPart:auxv:read.
4681 qXfer:memory-map:read:
4682 Fetch a memory map from the remote stub, including information about
4683 RAM, ROM, and flash memory devices.
4688 Erase and program a flash memory device.
4690 * Removed remote packets
4693 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4694 used it, and only gdbserver implemented it.
4696 *** Changes in GDB 6.5
4700 Renesas M32C/M16C m32c-elf
4702 Morpho Technologies ms1 ms1-elf
4706 init-if-undefined Initialize a convenience variable, but
4707 only if it doesn't already have a value.
4709 The following commands are presently only implemented for native GNU/Linux:
4711 checkpoint Save a snapshot of the program state.
4713 restart <n> Return the program state to a
4714 previously saved state.
4716 info checkpoints List currently saved checkpoints.
4718 delete-checkpoint <n> Delete a previously saved checkpoint.
4720 set|show detach-on-fork Tell gdb whether to detach from a newly
4721 forked process, or to keep debugging it.
4723 info forks List forks of the user program that
4724 are available to be debugged.
4726 fork <n> Switch to debugging one of several
4727 forks of the user program that are
4728 available to be debugged.
4730 delete-fork <n> Delete a fork from the list of forks
4731 that are available to be debugged (and
4732 kill the forked process).
4734 detach-fork <n> Delete a fork from the list of forks
4735 that are available to be debugged (and
4736 allow the process to continue).
4740 Morpho Technologies ms2 ms1-elf
4742 * Improved Windows host support
4744 GDB now builds as a cross debugger hosted on i686-mingw32, including
4745 native console support, and remote communications using either
4746 network sockets or serial ports.
4748 * Improved Modula-2 language support
4750 GDB can now print most types in the Modula-2 syntax. This includes:
4751 basic types, set types, record types, enumerated types, range types,
4752 pointer types and ARRAY types. Procedure var parameters are correctly
4753 printed and hexadecimal addresses and character constants are also
4754 written in the Modula-2 syntax. Best results can be obtained by using
4755 GNU Modula-2 together with the -gdwarf-2 command line option.
4759 The ARM rdi-share module.
4761 The Netware NLM debug server.
4763 *** Changes in GDB 6.4
4765 * New native configurations
4767 OpenBSD/arm arm*-*-openbsd*
4768 OpenBSD/mips64 mips64-*-openbsd*
4772 Morpho Technologies ms1 ms1-elf
4774 * New command line options
4776 --batch-silent As for --batch, but totally silent.
4777 --return-child-result The debugger will exist with the same value
4778 the child (debugged) program exited with.
4779 --eval-command COMMAND, -ex COMMAND
4780 Execute a single GDB CLI command. This may be
4781 specified multiple times and in conjunction
4782 with the --command (-x) option.
4784 * Deprecated commands removed
4786 The following commands, that were deprecated in 2000, have been
4790 set|show arm disassembly-flavor set|show arm disassembler
4791 othernames set arm disassembler
4792 set|show remotedebug set|show debug remote
4793 set|show archdebug set|show debug arch
4794 set|show eventdebug set|show debug event
4797 * New BSD user-level threads support
4799 It is now possible to debug programs using the user-level threads
4800 library on OpenBSD and FreeBSD. Currently supported (target)
4803 FreeBSD/amd64 x86_64-*-freebsd*
4804 FreeBSD/i386 i386-*-freebsd*
4805 OpenBSD/i386 i386-*-openbsd*
4807 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4808 are not yet supported.
4810 * New support for Matsushita MN10300 w/sim added
4811 (Work in progress). mn10300-elf.
4813 * REMOVED configurations and files
4815 VxWorks and the XDR protocol *-*-vxworks
4816 Motorola MCORE mcore-*-*
4817 National Semiconductor NS32000 ns32k-*-*
4819 * New "set print array-indexes" command
4821 After turning this setting "on", GDB prints the index of each element
4822 when displaying arrays. The default is "off" to preserve the previous
4825 * VAX floating point support
4827 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4829 * User-defined command support
4831 In addition to using $arg0..$arg9 for argument passing, it is now possible
4832 to use $argc to determine now many arguments have been passed. See the
4833 section on user-defined commands in the user manual for more information.
4835 *** Changes in GDB 6.3:
4837 * New command line option
4839 GDB now accepts -l followed by a number to set the timeout for remote
4842 * GDB works with GCC -feliminate-dwarf2-dups
4844 GDB now supports a more compact representation of DWARF-2 debug
4845 information using DW_FORM_ref_addr references. These are produced
4846 by GCC with the option -feliminate-dwarf2-dups and also by some
4847 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4848 to use -feliminate-dwarf2-dups.
4850 * Internationalization
4852 When supported by the host system, GDB will be built with
4853 internationalization (libintl). The task of marking up the sources is
4854 continued, we're looking forward to our first translation.
4858 Initial support for debugging programs compiled with the GNAT
4859 implementation of the Ada programming language has been integrated
4860 into GDB. In this release, support is limited to expression evaluation.
4862 * New native configurations
4864 GNU/Linux/m32r m32r-*-linux-gnu
4868 GDB's remote protocol now includes support for the 'p' packet. This
4869 packet is used to fetch individual registers from a remote inferior.
4871 * END-OF-LIFE registers[] compatibility module
4873 GDB's internal register infrastructure has been completely rewritten.
4874 The new infrastructure making possible the implementation of key new
4875 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4878 GDB 6.3 will be the last release to include the the registers[]
4879 compatibility module that allowed out-of-date configurations to
4880 continue to work. This change directly impacts the following
4890 powerpc bdm protocol
4892 Unless there is activity to revive these configurations, they will be
4893 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4895 * OBSOLETE configurations and files
4897 Configurations that have been declared obsolete in this release have
4898 been commented out. Unless there is activity to revive these
4899 configurations, the next release of GDB will have their sources
4900 permanently REMOVED.
4909 *** Changes in GDB 6.2.1:
4911 * MIPS `break main; run' gave an heuristic-fence-post warning
4913 When attempting to run even a simple program, a warning about
4914 heuristic-fence-post being hit would be reported. This problem has
4917 * MIPS IRIX 'long double' crashed GDB
4919 When examining a long double variable, GDB would get a segmentation
4920 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4921 IRIX long double values).
4925 A bug in the VAX stack code was causing problems with the "next"
4926 command. This problem has been fixed.
4928 *** Changes in GDB 6.2:
4930 * Fix for ``many threads''
4932 On GNU/Linux systems that use the NPTL threads library, a program
4933 rapidly creating and deleting threads would confuse GDB leading to the
4936 ptrace: No such process.
4937 thread_db_get_info: cannot get thread info: generic error
4939 This problem has been fixed.
4941 * "-async" and "-noasync" options removed.
4943 Support for the broken "-noasync" option has been removed (it caused
4946 * New ``start'' command.
4948 This command runs the program until the begining of the main procedure.
4950 * New BSD Kernel Data Access Library (libkvm) interface
4952 Using ``target kvm'' it is now possible to debug kernel core dumps and
4953 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4954 platforms. Currently supported (native-only) configurations are:
4956 FreeBSD/amd64 x86_64-*-freebsd*
4957 FreeBSD/i386 i?86-*-freebsd*
4958 NetBSD/i386 i?86-*-netbsd*
4959 NetBSD/m68k m68*-*-netbsd*
4960 NetBSD/sparc sparc-*-netbsd*
4961 OpenBSD/amd64 x86_64-*-openbsd*
4962 OpenBSD/i386 i?86-*-openbsd*
4963 OpenBSD/m68k m68*-openbsd*
4964 OpenBSD/sparc sparc-*-openbsd*
4966 * Signal trampoline code overhauled
4968 Many generic problems with GDB's signal handling code have been fixed.
4969 These include: backtraces through non-contiguous stacks; recognition
4970 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4971 call; backtrace through a signal trampoline; step into and out of
4972 signal handlers; and single-stepping in the signal trampoline.
4974 Please note that kernel bugs are a limiting factor here. These
4975 features have been shown to work on an s390 GNU/Linux system that
4976 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4978 * Cygwin support for DWARF 2 added.
4980 * New native configurations
4982 GNU/Linux/hppa hppa*-*-linux*
4983 OpenBSD/hppa hppa*-*-openbsd*
4984 OpenBSD/m68k m68*-*-openbsd*
4985 OpenBSD/m88k m88*-*-openbsd*
4986 OpenBSD/powerpc powerpc-*-openbsd*
4987 NetBSD/vax vax-*-netbsd*
4988 OpenBSD/vax vax-*-openbsd*
4990 * END-OF-LIFE frame compatibility module
4992 GDB's internal frame infrastructure has been completely rewritten.
4993 The new infrastructure making it possible to support key new features
4994 including DWARF 2 Call Frame Information. To aid in the task of
4995 migrating old configurations to this new infrastructure, a
4996 compatibility module, that allowed old configurations to continue to
4997 work, was also included.
4999 GDB 6.2 will be the last release to include this frame compatibility
5000 module. This change directly impacts the following configurations:
5010 Unless there is activity to revive these configurations, they will be
5011 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5013 * REMOVED configurations and files
5015 Sun 3, running SunOS 3 m68*-*-sunos3*
5016 Sun 3, running SunOS 4 m68*-*-sunos4*
5017 Sun 2, running SunOS 3 m68000-*-sunos3*
5018 Sun 2, running SunOS 4 m68000-*-sunos4*
5019 Motorola 680x0 running LynxOS m68*-*-lynxos*
5020 AT&T 3b1/Unix pc m68*-att-*
5021 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5022 decstation mips-dec-* mips-little-*
5023 riscos mips-*-riscos* mips-*-sysv*
5024 sonymips mips-sony-*
5025 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5027 *** Changes in GDB 6.1.1:
5029 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5031 The TUI (Text-mode User Interface) is now built as part of a default
5032 GDB configuration. It is enabled by either selecting the TUI with the
5033 command line option "-i=tui" or by running the separate "gdbtui"
5034 program. For more information on the TUI, see the manual "Debugging
5037 * Pending breakpoint support (also included in GDB 6.1)
5039 Support has been added to allow you to specify breakpoints in shared
5040 libraries that have not yet been loaded. If a breakpoint location
5041 cannot be found, and the "breakpoint pending" option is set to auto,
5042 GDB queries you if you wish to make the breakpoint pending on a future
5043 shared-library load. If and when GDB resolves the breakpoint symbol,
5044 the pending breakpoint is removed as one or more regular breakpoints
5047 Pending breakpoints are very useful for GCJ Java debugging.
5049 * Fixed ISO-C build problems
5051 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5052 non ISO-C code that stopped them being built using a more strict ISO-C
5053 compiler (e.g., IBM's C compiler).
5055 * Fixed build problem on IRIX 5
5057 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5058 wasn't able to compile compile on an IRIX 5 system.
5060 * Added execute permission to gdb/gdbserver/configure
5062 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5063 permission. This bug would cause configure to fail on a number of
5064 systems (Solaris, IRIX). Ref: server/519.
5066 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5068 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5069 has been updated to use constant array sizes.
5071 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5073 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5074 its generated DWARF Call Frame Info. This encoding was causing GDB to
5075 panic, that panic has been fixed. Ref: gdb/1628.
5077 * Fixed a problem when examining parameters in shared library code.
5079 When examining parameters in optimized shared library code generated
5080 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5081 not available''. GDB now correctly displays the variable's value.
5083 *** Changes in GDB 6.1:
5085 * Removed --with-mmalloc
5087 Support for the mmalloc memory manager has been removed, as it
5088 conflicted with the internal gdb byte cache.
5090 * Changes in AMD64 configurations
5092 The AMD64 target now includes the %cs and %ss registers. As a result
5093 the AMD64 remote protocol has changed; this affects the floating-point
5094 and SSE registers. If you rely on those registers for your debugging,
5095 you should upgrade gdbserver on the remote side.
5097 * Revised SPARC target
5099 The SPARC target has been completely revised, incorporating the
5100 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5101 support for LynxOS and SunOS 4 has been dropped. Calling functions
5102 from within GDB on operating systems with a non-executable stack
5103 (Solaris, OpenBSD) now works.
5107 GDB has a new C++ demangler which does a better job on the mangled
5108 names generated by current versions of g++. It also runs faster, so
5109 with this and other changes gdb should now start faster on large C++
5112 * DWARF 2 Location Expressions
5114 GDB support for location expressions has been extended to support function
5115 arguments and frame bases. Older versions of GDB could crash when they
5118 * C++ nested types and namespaces
5120 GDB's support for nested types and namespaces in C++ has been
5121 improved, especially if you use the DWARF 2 debugging format. (This
5122 is the default for recent versions of GCC on most platforms.)
5123 Specifically, if you have a class "Inner" defined within a class or
5124 namespace "Outer", then GDB realizes that the class's name is
5125 "Outer::Inner", not simply "Inner". This should greatly reduce the
5126 frequency of complaints about not finding RTTI symbols. In addition,
5127 if you are stopped at inside of a function defined within a namespace,
5128 GDB modifies its name lookup accordingly.
5130 * New native configurations
5132 NetBSD/amd64 x86_64-*-netbsd*
5133 OpenBSD/amd64 x86_64-*-openbsd*
5134 OpenBSD/alpha alpha*-*-openbsd*
5135 OpenBSD/sparc sparc-*-openbsd*
5136 OpenBSD/sparc64 sparc64-*-openbsd*
5138 * New debugging protocols
5140 M32R with SDI protocol m32r-*-elf*
5142 * "set prompt-escape-char" command deleted.
5144 The command "set prompt-escape-char" has been deleted. This command,
5145 and its very obscure effet on GDB's prompt, was never documented,
5146 tested, nor mentioned in the NEWS file.
5148 * OBSOLETE configurations and files
5150 Configurations that have been declared obsolete in this release have
5151 been commented out. Unless there is activity to revive these
5152 configurations, the next release of GDB will have their sources
5153 permanently REMOVED.
5155 Sun 3, running SunOS 3 m68*-*-sunos3*
5156 Sun 3, running SunOS 4 m68*-*-sunos4*
5157 Sun 2, running SunOS 3 m68000-*-sunos3*
5158 Sun 2, running SunOS 4 m68000-*-sunos4*
5159 Motorola 680x0 running LynxOS m68*-*-lynxos*
5160 AT&T 3b1/Unix pc m68*-att-*
5161 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5162 decstation mips-dec-* mips-little-*
5163 riscos mips-*-riscos* mips-*-sysv*
5164 sonymips mips-sony-*
5165 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5167 * REMOVED configurations and files
5169 SGI Irix-4.x mips-sgi-irix4 or iris4
5170 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5171 Z8000 simulator z8k-zilog-none or z8ksim
5172 Matsushita MN10200 w/simulator mn10200-*-*
5173 H8/500 simulator h8500-hitachi-hms or h8500hms
5174 HP/PA running BSD hppa*-*-bsd*
5175 HP/PA running OSF/1 hppa*-*-osf*
5176 HP/PA Pro target hppa*-*-pro*
5177 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5178 386BSD i[3456]86-*-bsd*
5179 Sequent family i[3456]86-sequent-sysv4*
5180 i[3456]86-sequent-sysv*
5181 i[3456]86-sequent-bsd*
5182 SPARC running LynxOS sparc-*-lynxos*
5183 SPARC running SunOS 4 sparc-*-sunos4*
5184 Tsqware Sparclet sparclet-*-*
5185 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5187 *** Changes in GDB 6.0:
5191 Support for debugging the Objective-C programming language has been
5192 integrated into GDB.
5194 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5196 DWARF 2's Call Frame Information makes available compiler generated
5197 information that more exactly describes the program's run-time stack.
5198 By using this information, GDB is able to provide more robust stack
5201 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5202 have been updated to use a new backtrace mechanism which includes
5203 DWARF 2 CFI support.
5207 GDB's remote protocol has been extended to include support for hosted
5208 file I/O (where the remote target uses GDB's file system). See GDB's
5209 remote protocol documentation for details.
5211 * All targets using the new architecture framework.
5213 All of GDB's targets have been updated to use the new internal
5214 architecture framework. The way is now open for future GDB releases
5215 to include cross-architecture native debugging support (i386 on amd64,
5218 * GNU/Linux's Thread Local Storage (TLS)
5220 GDB now includes support for for the GNU/Linux implementation of
5221 per-thread variables.
5223 * GNU/Linux's Native POSIX Thread Library (NPTL)
5225 GDB's thread code has been updated to work with either the new
5226 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5228 * Separate debug info.
5230 GDB, in conjunction with BINUTILS, now supports a mechanism for
5231 automatically loading debug information from a separate file. Instead
5232 of shipping full debug and non-debug versions of system libraries,
5233 system integrators can now instead ship just the stripped libraries
5234 and optional debug files.
5236 * DWARF 2 Location Expressions
5238 DWARF 2 Location Expressions allow the compiler to more completely
5239 describe the location of variables (even in optimized code) to the
5242 GDB now includes preliminary support for location expressions (support
5243 for DW_OP_piece is still missing).
5247 A number of long standing bugs that caused GDB to die while starting a
5248 Java application have been fixed. GDB's Java support is now
5249 considered "useable".
5251 * GNU/Linux support for fork, vfork, and exec.
5253 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5254 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5257 * GDB supports logging output to a file
5259 There are two new commands, "set logging" and "show logging", which can be
5260 used to capture GDB's output to a file.
5262 * The meaning of "detach" has changed for gdbserver
5264 The "detach" command will now resume the application, as documented. To
5265 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5268 * d10v, m68hc11 `regs' command deprecated
5270 The `info registers' command has been updated so that it displays the
5271 registers using a format identical to the old `regs' command.
5275 A new command, "maint set profile on/off", has been added. This command can
5276 be used to enable or disable profiling while running GDB, to profile a
5277 session or a set of commands. In addition there is a new configure switch,
5278 "--enable-profiling", which will cause GDB to be compiled with profiling
5279 data, for more informative profiling results.
5281 * Default MI syntax changed to "mi2".
5283 The default MI (machine interface) syntax, enabled by the command line
5284 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5285 "mi1", can be enabled by specifying the option "-i=mi1".
5287 Support for the original "mi0" syntax (included in GDB 5.0) has been
5290 Fix for gdb/192: removed extraneous space when displaying frame level.
5291 Fix for gdb/672: update changelist is now output in mi list format.
5292 Fix for gdb/702: a -var-assign that updates the value now shows up
5293 in a subsequent -var-update.
5295 * New native configurations.
5297 FreeBSD/amd64 x86_64-*-freebsd*
5299 * Multi-arched targets.
5301 HP/PA HPUX11 hppa*-*-hpux*
5302 Renesas M32R/D w/simulator m32r-*-elf*
5304 * OBSOLETE configurations and files
5306 Configurations that have been declared obsolete in this release have
5307 been commented out. Unless there is activity to revive these
5308 configurations, the next release of GDB will have their sources
5309 permanently REMOVED.
5311 Z8000 simulator z8k-zilog-none or z8ksim
5312 Matsushita MN10200 w/simulator mn10200-*-*
5313 H8/500 simulator h8500-hitachi-hms or h8500hms
5314 HP/PA running BSD hppa*-*-bsd*
5315 HP/PA running OSF/1 hppa*-*-osf*
5316 HP/PA Pro target hppa*-*-pro*
5317 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5318 Sequent family i[3456]86-sequent-sysv4*
5319 i[3456]86-sequent-sysv*
5320 i[3456]86-sequent-bsd*
5321 Tsqware Sparclet sparclet-*-*
5322 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5324 * REMOVED configurations and files
5327 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5328 IBM AIX PS/2 i[3456]86-*-aix
5329 i386 running Mach 3.0 i[3456]86-*-mach3*
5330 i386 running Mach i[3456]86-*-mach*
5331 i386 running OSF/1 i[3456]86-*osf1mk*
5332 HP/Apollo 68k Family m68*-apollo*-sysv*,
5334 m68*-hp-bsd*, m68*-hp-hpux*
5335 Argonaut Risc Chip (ARC) arc-*-*
5336 Mitsubishi D30V d30v-*-*
5337 Fujitsu FR30 fr30-*-elf*
5338 OS/9000 i[34]86-*-os9k
5339 I960 with MON960 i960-*-coff
5341 * MIPS $fp behavior changed
5343 The convenience variable $fp, for the MIPS, now consistently returns
5344 the address of the current frame's base. Previously, depending on the
5345 context, $fp could refer to either $sp or the current frame's base
5346 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5347 The GNU Source-Level Debugger''.
5349 *** Changes in GDB 5.3:
5351 * GNU/Linux shared library multi-threaded performance improved.
5353 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5354 `/proc', in preference to `ptrace' for memory reads. This may result
5355 in an improvement in the start-up time of multi-threaded, shared
5356 library applications when run under GDB. One GDB user writes: ``loads
5357 shared libs like mad''.
5359 * ``gdbserver'' now supports multi-threaded applications on some targets
5361 Support for debugging multi-threaded applications which use
5362 the GNU/Linux LinuxThreads package has been added for
5363 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5364 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5366 * GDB now supports C/C++ preprocessor macros.
5368 GDB now expands preprocessor macro invocations in C/C++ expressions,
5369 and provides various commands for showing macro definitions and how
5372 The new command `macro expand EXPRESSION' expands any macro
5373 invocations in expression, and shows the result.
5375 The new command `show macro MACRO-NAME' shows the definition of the
5376 macro named MACRO-NAME, and where it was defined.
5378 Most compilers don't include information about macros in the debugging
5379 information by default. In GCC 3.1, for example, you need to compile
5380 your program with the options `-gdwarf-2 -g3'. If the macro
5381 information is present in the executable, GDB will read it.
5383 * Multi-arched targets.
5385 DEC Alpha (partial) alpha*-*-*
5386 DEC VAX (partial) vax-*-*
5388 National Semiconductor NS32000 (partial) ns32k-*-*
5389 Motorola 68000 (partial) m68k-*-*
5390 Motorola MCORE mcore-*-*
5394 Fujitsu FRV architecture added by Red Hat frv*-*-*
5397 * New native configurations
5399 Alpha NetBSD alpha*-*-netbsd*
5400 SH NetBSD sh*-*-netbsdelf*
5401 MIPS NetBSD mips*-*-netbsd*
5402 UltraSPARC NetBSD sparc64-*-netbsd*
5404 * OBSOLETE configurations and files
5406 Configurations that have been declared obsolete in this release have
5407 been commented out. Unless there is activity to revive these
5408 configurations, the next release of GDB will have their sources
5409 permanently REMOVED.
5411 Mitsubishi D30V d30v-*-*
5412 OS/9000 i[34]86-*-os9k
5413 IBM AIX PS/2 i[3456]86-*-aix
5414 Fujitsu FR30 fr30-*-elf*
5415 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5416 Argonaut Risc Chip (ARC) arc-*-*
5417 i386 running Mach 3.0 i[3456]86-*-mach3*
5418 i386 running Mach i[3456]86-*-mach*
5419 i386 running OSF/1 i[3456]86-*osf1mk*
5420 HP/Apollo 68k Family m68*-apollo*-sysv*,
5422 m68*-hp-bsd*, m68*-hp-hpux*
5423 I960 with MON960 i960-*-coff
5425 * OBSOLETE languages
5427 CHILL, a Pascal like language used by telecommunications companies.
5429 * REMOVED configurations and files
5431 AMD 29k family via UDI a29k-amd-udi, udi29k
5432 A29K VxWorks a29k-*-vxworks
5433 AMD 29000 embedded, using EBMON a29k-none-none
5434 AMD 29000 embedded with COFF a29k-none-coff
5435 AMD 29000 embedded with a.out a29k-none-aout
5437 testsuite/gdb.hp/gdb.threads-hp/ directory
5439 * New command "set max-user-call-depth <nnn>"
5441 This command allows the user to limit the call depth of user-defined
5442 commands. The default is 1024.
5444 * Changes in FreeBSD/i386 native debugging.
5446 Support for the "generate-core-file" has been added.
5448 * New commands "dump", "append", and "restore".
5450 These commands allow data to be copied from target memory
5451 to a bfd-format or binary file (dump and append), and back
5452 from a file into memory (restore).
5454 * Improved "next/step" support on multi-processor Alpha Tru64.
5456 The previous single-step mechanism could cause unpredictable problems,
5457 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5458 of a software single-step mechanism prevents this.
5460 *** Changes in GDB 5.2.1:
5468 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5469 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5470 Fix, by Joel Brobecker imported from mainline.
5472 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5473 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5474 Fix, by Fred Fish, imported from mainline.
5476 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5477 Surprisingly enough, it works now.
5478 By Michal Ludvig, imported from mainline.
5480 i386 hardware watchpoint support:
5481 avoid misses on second run for some targets.
5482 By Pierre Muller, imported from mainline.
5484 *** Changes in GDB 5.2:
5486 * New command "set trust-readonly-sections on[off]".
5488 This command is a hint that tells gdb that read-only sections
5489 really are read-only (ie. that their contents will not change).
5490 In this mode, gdb will go to the object file rather than the
5491 target to read memory from read-only sections (such as ".text").
5492 This can be a significant performance improvement on some
5493 (notably embedded) targets.
5495 * New command "generate-core-file" (or "gcore").
5497 This new gdb command allows the user to drop a core file of the child
5498 process state at any time. So far it's been implemented only for
5499 GNU/Linux and Solaris, but should be relatively easily ported to other
5500 hosts. Argument is core file name (defaults to core.<pid>).
5502 * New command line option
5504 GDB now accepts --pid or -p followed by a process id.
5506 * Change in command line behavior -- corefiles vs. process ids.
5508 There is a subtle behavior in the way in which GDB handles
5509 command line arguments. The first non-flag argument is always
5510 a program to debug, but the second non-flag argument may either
5511 be a corefile or a process id. Previously, GDB would attempt to
5512 open the second argument as a corefile, and if that failed, would
5513 issue a superfluous error message and then attempt to attach it as
5514 a process. Now, if the second argument begins with a non-digit,
5515 it will be treated as a corefile. If it begins with a digit,
5516 GDB will attempt to attach it as a process, and if no such process
5517 is found, will then attempt to open it as a corefile.
5519 * Changes in ARM configurations.
5521 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5522 configuration is fully multi-arch.
5524 * New native configurations
5526 ARM NetBSD arm*-*-netbsd*
5527 x86 OpenBSD i[3456]86-*-openbsd*
5528 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5529 Sparc64 running FreeBSD sparc64-*-freebsd*
5533 Sanyo XStormy16 xstormy16-elf
5535 * OBSOLETE configurations and files
5537 Configurations that have been declared obsolete in this release have
5538 been commented out. Unless there is activity to revive these
5539 configurations, the next release of GDB will have their sources
5540 permanently REMOVED.
5542 AMD 29k family via UDI a29k-amd-udi, udi29k
5543 A29K VxWorks a29k-*-vxworks
5544 AMD 29000 embedded, using EBMON a29k-none-none
5545 AMD 29000 embedded with COFF a29k-none-coff
5546 AMD 29000 embedded with a.out a29k-none-aout
5548 testsuite/gdb.hp/gdb.threads-hp/ directory
5550 * REMOVED configurations and files
5552 TI TMS320C80 tic80-*-*
5554 PowerPC Solaris powerpcle-*-solaris*
5555 PowerPC Windows NT powerpcle-*-cygwin32
5556 PowerPC Netware powerpc-*-netware*
5557 Harris/CXUX m88k m88*-harris-cxux*
5558 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5559 ns32k-utek-sysv* ns32k-utek-*
5560 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5561 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5562 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5563 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5564 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5566 * Changes to command line processing
5568 The new `--args' feature can be used to specify command-line arguments
5569 for the inferior from gdb's command line.
5571 * Changes to key bindings
5573 There is a new `operate-and-get-next' function bound to `C-o'.
5575 *** Changes in GDB 5.1.1
5577 Fix compile problem on DJGPP.
5579 Fix a problem with floating-point registers on the i386 being
5582 Fix to stop GDB crashing on .debug_str debug info.
5584 Numerous documentation fixes.
5586 Numerous testsuite fixes.
5588 *** Changes in GDB 5.1:
5590 * New native configurations
5592 Alpha FreeBSD alpha*-*-freebsd*
5593 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5594 MIPS GNU/Linux mips*-*-linux*
5595 MIPS SGI Irix 6.x mips*-sgi-irix6*
5596 ia64 AIX ia64-*-aix*
5597 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5601 Motorola 68HC11 and 68HC12 m68hc11-elf
5603 UltraSparc running GNU/Linux sparc64-*-linux*
5605 * OBSOLETE configurations and files
5607 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5608 Harris/CXUX m88k m88*-harris-cxux*
5609 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5610 ns32k-utek-sysv* ns32k-utek-*
5611 TI TMS320C80 tic80-*-*
5613 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5614 PowerPC Solaris powerpcle-*-solaris*
5615 PowerPC Windows NT powerpcle-*-cygwin32
5616 PowerPC Netware powerpc-*-netware*
5617 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5618 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5619 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5620 Apple Macintosh (MPW) host N/A
5622 stuff.c (Program to stuff files into a specially prepared space in kdb)
5623 kdb-start.c (Main loop for the standalone kernel debugger)
5625 Configurations that have been declared obsolete in this release have
5626 been commented out. Unless there is activity to revive these
5627 configurations, the next release of GDB will have their sources
5628 permanently REMOVED.
5630 * REMOVED configurations and files
5632 Altos 3068 m68*-altos-*
5633 Convex c1-*-*, c2-*-*
5635 ARM RISCix arm-*-* (as host)
5639 * GDB has been converted to ISO C.
5641 GDB's source code has been converted to ISO C. In particular, the
5642 sources are fully protoized, and rely on standard headers being
5647 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5649 * The MI enabled by default.
5651 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5652 revised and enabled by default. Packages which use GDB as a debugging
5653 engine behind a UI or another front end are encouraged to switch to
5654 using the GDB/MI interface, instead of the old annotations interface
5655 which is now deprecated.
5657 * Support for debugging Pascal programs.
5659 GDB now includes support for debugging Pascal programs. The following
5660 main features are supported:
5662 - Pascal-specific data types such as sets;
5664 - automatic recognition of Pascal sources based on file-name
5667 - Pascal-style display of data types, variables, and functions;
5669 - a Pascal expression parser.
5671 However, some important features are not yet supported.
5673 - Pascal string operations are not supported at all;
5675 - there are some problems with boolean types;
5677 - Pascal type hexadecimal constants are not supported
5678 because they conflict with the internal variables format;
5680 - support for Pascal objects and classes is not full yet;
5682 - unlike Pascal, GDB is case-sensitive for symbol names.
5684 * Changes in completion.
5686 Commands such as `shell', `run' and `set args', which pass arguments
5687 to inferior programs, now complete on file names, similar to what
5688 users expect at the shell prompt.
5690 Commands which accept locations, such as `disassemble', `print',
5691 `breakpoint', `until', etc. now complete on filenames as well as
5692 program symbols. Thus, if you type "break foob TAB", and the source
5693 files linked into the programs include `foobar.c', that file name will
5694 be one of the candidates for completion. However, file names are not
5695 considered for completion after you typed a colon that delimits a file
5696 name from a name of a function in that file, as in "break foo.c:bar".
5698 `set demangle-style' completes on available demangling styles.
5700 * New platform-independent commands:
5702 It is now possible to define a post-hook for a command as well as a
5703 hook that runs before the command. For more details, see the
5704 documentation of `hookpost' in the GDB manual.
5706 * Changes in GNU/Linux native debugging.
5708 Support for debugging multi-threaded programs has been completely
5709 revised for all platforms except m68k and sparc. You can now debug as
5710 many threads as your system allows you to have.
5712 Attach/detach is supported for multi-threaded programs.
5714 Support for SSE registers was added for x86. This doesn't work for
5715 multi-threaded programs though.
5717 * Changes in MIPS configurations.
5719 Multi-arch support is enabled for all MIPS configurations.
5721 GDB can now be built as native debugger on SGI Irix 6.x systems for
5722 debugging n32 executables. (Debugging 64-bit executables is not yet
5725 * Unified support for hardware watchpoints in all x86 configurations.
5727 Most (if not all) native x86 configurations support hardware-assisted
5728 breakpoints and watchpoints in a unified manner. This support
5729 implements debug register sharing between watchpoints, which allows to
5730 put a virtually infinite number of watchpoints on the same address,
5731 and also supports watching regions up to 16 bytes with several debug
5734 The new maintenance command `maintenance show-debug-regs' toggles
5735 debugging print-outs in functions that insert, remove, and test
5736 watchpoints and hardware breakpoints.
5738 * Changes in the DJGPP native configuration.
5740 New command ``info dos sysinfo'' displays assorted information about
5741 the CPU, OS, memory, and DPMI server.
5743 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5744 display information about segment descriptors stored in GDT, LDT, and
5747 New commands ``info dos pde'' and ``info dos pte'' display entries
5748 from Page Directory and Page Tables (for now works with CWSDPMI only).
5749 New command ``info dos address-pte'' displays the Page Table entry for
5750 a given linear address.
5752 GDB can now pass command lines longer than 126 characters to the
5753 program being debugged (requires an update to the libdbg.a library
5754 which is part of the DJGPP development kit).
5756 DWARF2 debug info is now supported.
5758 It is now possible to `step' and `next' through calls to `longjmp'.
5760 * Changes in documentation.
5762 All GDB documentation was converted to GFDL, the GNU Free
5763 Documentation License.
5765 Tracepoints-related commands are now fully documented in the GDB
5768 TUI, the Text-mode User Interface, is now documented in the manual.
5770 Tracepoints-related commands are now fully documented in the GDB
5773 The "GDB Internals" manual now has an index. It also includes
5774 documentation of `ui_out' functions, GDB coding standards, x86
5775 hardware watchpoints, and memory region attributes.
5777 * GDB's version number moved to ``version.in''
5779 The Makefile variable VERSION has been replaced by the file
5780 ``version.in''. People creating GDB distributions should update the
5781 contents of this file.
5785 GUD support is now a standard part of the EMACS distribution.
5787 *** Changes in GDB 5.0:
5789 * Improved support for debugging FP programs on x86 targets
5791 Unified and much-improved support for debugging floating-point
5792 programs on all x86 targets. In particular, ``info float'' now
5793 displays the FP registers in the same format on all x86 targets, with
5794 greater level of detail.
5796 * Improvements and bugfixes in hardware-assisted watchpoints
5798 It is now possible to watch array elements, struct members, and
5799 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5800 on x86 targets no longer erroneously trigger when the address is
5803 * Improvements in the native DJGPP version of GDB
5805 The distribution now includes all the scripts and auxiliary files
5806 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5807 machines ``out of the box''.
5809 The DJGPP version can now debug programs that use signals. It is
5810 possible to catch signals that happened in the debuggee, deliver
5811 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5812 would kill the program being debugged.) Programs that hook hardware
5813 interrupts (keyboard, timer, etc.) can also be debugged.
5815 It is now possible to debug DJGPP programs that redirect their
5816 standard handles or switch them to raw (as opposed to cooked) mode, or
5817 even close them. The command ``run < foo > bar'' works as expected,
5818 and ``info terminal'' reports useful information about the debuggee's
5819 terminal, including raw/cooked mode, redirection, etc.
5821 The DJGPP version now uses termios functions for console I/O, which
5822 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5825 DOS-style file names with drive letters are now fully supported by
5828 It is now possible to debug DJGPP programs that switch their working
5829 directory. It is also possible to rerun the debuggee any number of
5830 times without restarting GDB; thus, you can use the same setup,
5831 breakpoints, etc. for many debugging sessions.
5833 * New native configurations
5835 ARM GNU/Linux arm*-*-linux*
5836 PowerPC GNU/Linux powerpc-*-linux*
5840 Motorola MCore mcore-*-*
5841 x86 VxWorks i[3456]86-*-vxworks*
5842 PowerPC VxWorks powerpc-*-vxworks*
5843 TI TMS320C80 tic80-*-*
5845 * OBSOLETE configurations
5847 Altos 3068 m68*-altos-*
5848 Convex c1-*-*, c2-*-*
5850 ARM RISCix arm-*-* (as host)
5853 Configurations that have been declared obsolete will be commented out,
5854 but the code will be left in place. If there is no activity to revive
5855 these configurations before the next release of GDB, the sources will
5856 be permanently REMOVED.
5858 * Gould support removed
5860 Support for the Gould PowerNode and NP1 has been removed.
5862 * New features for SVR4
5864 On SVR4 native platforms (such as Solaris), if you attach to a process
5865 without first loading a symbol file, GDB will now attempt to locate and
5866 load symbols from the running process's executable file.
5868 * Many C++ enhancements
5870 C++ support has been greatly improved. Overload resolution now works properly
5871 in almost all cases. RTTI support is on the way.
5873 * Remote targets can connect to a sub-program
5875 A popen(3) style serial-device has been added. This device starts a
5876 sub-process (such as a stand-alone simulator) and then communicates
5877 with that. The sub-program to run is specified using the syntax
5878 ``|<program> <args>'' vis:
5880 (gdb) set remotedebug 1
5881 (gdb) target extended-remote |mn10300-elf-sim program-args
5883 * MIPS 64 remote protocol
5885 A long standing bug in the mips64 remote protocol where by GDB
5886 expected certain 32 bit registers (ex SR) to be transfered as 32
5887 instead of 64 bits has been fixed.
5889 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5890 added to provide backward compatibility with older versions of GDB.
5892 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5894 The command ``set remotebinarydownload'' command has been replaced by
5895 ``set remote X-packet''. Other commands in ``set remote'' family
5896 include ``set remote P-packet''.
5898 * Breakpoint commands accept ranges.
5900 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5901 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5902 ``tracepoint passcount'' also accepts a range of tracepoints.
5904 * ``apropos'' command added.
5906 The ``apropos'' command searches through command names and
5907 documentation strings, printing out matches, making it much easier to
5908 try to find a command that does what you are looking for.
5912 A new machine oriented interface (MI) has been added to GDB. This
5913 interface is designed for debug environments running GDB as a separate
5914 process. This is part of the long term libGDB project. See the
5915 "GDB/MI" chapter of the GDB manual for further information. It can be
5916 enabled by configuring with:
5918 .../configure --enable-gdbmi
5920 *** Changes in GDB-4.18:
5922 * New native configurations
5924 HP-UX 10.20 hppa*-*-hpux10.20
5925 HP-UX 11.x hppa*-*-hpux11.0*
5926 M68K GNU/Linux m68*-*-linux*
5930 Fujitsu FR30 fr30-*-elf*
5931 Intel StrongARM strongarm-*-*
5932 Mitsubishi D30V d30v-*-*
5934 * OBSOLETE configurations
5936 Gould PowerNode, NP1 np1-*-*, pn-*-*
5938 Configurations that have been declared obsolete will be commented out,
5939 but the code will be left in place. If there is no activity to revive
5940 these configurations before the next release of GDB, the sources will
5941 be permanently REMOVED.
5945 As a compatibility experiment, GDB's source files buildsym.h and
5946 buildsym.c have been converted to pure standard C, no longer
5947 containing any K&R compatibility code. We believe that all systems in
5948 use today either come with a standard C compiler, or have a GCC port
5949 available. If this is not true, please report the affected
5950 configuration to bug-gdb@gnu.org immediately. See the README file for
5951 information about getting a standard C compiler if you don't have one
5956 GDB now uses readline 2.2.
5958 * set extension-language
5960 You can now control the mapping between filename extensions and source
5961 languages by using the `set extension-language' command. For instance,
5962 you can ask GDB to treat .c files as C++ by saying
5963 set extension-language .c c++
5964 The command `info extensions' lists all of the recognized extensions
5965 and their associated languages.
5967 * Setting processor type for PowerPC and RS/6000
5969 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5970 you can use the `set processor' command to specify what variant of the
5971 PowerPC family you are debugging. The command
5975 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5976 following PowerPC and RS6000 variants:
5978 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5979 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5981 403GC IBM PowerPC 403GC
5982 505 Motorola PowerPC 505
5983 860 Motorola PowerPC 860 or 850
5984 601 Motorola PowerPC 601
5985 602 Motorola PowerPC 602
5986 603 Motorola/IBM PowerPC 603 or 603e
5987 604 Motorola PowerPC 604 or 604e
5988 750 Motorola/IBM PowerPC 750 or 750
5990 At the moment, this command just tells GDB what to name the
5991 special-purpose processor registers. Since almost all the affected
5992 registers are inaccessible to user-level programs, this command is
5993 only useful for remote debugging in its present form.
5997 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5998 more extensive support for HP-UX. Added features include shared
5999 library support, kernel threads and hardware watchpoints for 11.00,
6000 support for HP's ANSI C and C++ compilers, and a compatibility mode
6001 for xdb and dbx commands.
6005 HP's donation includes the new concept of catchpoints, which is a
6006 generalization of the old catch command. On HP-UX, it is now possible
6007 to catch exec, fork, and vfork, as well as library loading.
6009 This means that the existing catch command has changed; its first
6010 argument now specifies the type of catch to be set up. See the
6011 output of "help catch" for a list of catchpoint types.
6013 * Debugging across forks
6015 On HP-UX, you can choose which process to debug when a fork() happens
6020 HP has donated a curses-based terminal user interface (TUI). To get
6021 it, build with --enable-tui. Although this can be enabled for any
6022 configuration, at present it only works for native HP debugging.
6024 * GDB remote protocol additions
6026 A new protocol packet 'X' that writes binary data is now available.
6027 Default behavior is to try 'X', then drop back to 'M' if the stub
6028 fails to respond. The settable variable `remotebinarydownload'
6029 allows explicit control over the use of 'X'.
6031 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6032 full 64-bit address. The command
6034 set remoteaddresssize 32
6036 can be used to revert to the old behaviour. For existing remote stubs
6037 the change should not be noticed, as the additional address information
6040 In order to assist in debugging stubs, you may use the maintenance
6041 command `packet' to send any text string to the stub. For instance,
6043 maint packet heythere
6045 sends the packet "$heythere#<checksum>". Note that it is very easy to
6046 disrupt a debugging session by sending the wrong packet at the wrong
6049 The compare-sections command allows you to compare section data on the
6050 target to what is in the executable file without uploading or
6051 downloading, by comparing CRC checksums.
6053 * Tracing can collect general expressions
6055 You may now collect general expressions at tracepoints. This requires
6056 further additions to the target-side stub; see tracepoint.c and
6057 doc/agentexpr.texi for further details.
6059 * mask-address variable for Mips
6061 For Mips targets, you may control the zeroing of the upper 32 bits of
6062 a 64-bit address by entering `set mask-address on'. This is mainly
6063 of interest to users of embedded R4xxx and R5xxx processors.
6065 * Higher serial baud rates
6067 GDB's serial code now allows you to specify baud rates 57600, 115200,
6068 230400, and 460800 baud. (Note that your host system may not be able
6069 to achieve all of these rates.)
6073 The i960 configuration now includes an initial implementation of a
6074 builtin simulator, contributed by Jim Wilson.
6077 *** Changes in GDB-4.17:
6079 * New native configurations
6081 Alpha GNU/Linux alpha*-*-linux*
6082 Unixware 2.x i[3456]86-unixware2*
6083 Irix 6.x mips*-sgi-irix6*
6084 PowerPC GNU/Linux powerpc-*-linux*
6085 PowerPC Solaris powerpcle-*-solaris*
6086 Sparc GNU/Linux sparc-*-linux*
6087 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6091 Argonaut Risc Chip (ARC) arc-*-*
6092 Hitachi H8/300S h8300*-*-*
6093 Matsushita MN10200 w/simulator mn10200-*-*
6094 Matsushita MN10300 w/simulator mn10300-*-*
6095 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6096 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6097 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6098 Mitsubishi D10V w/simulator d10v-*-*
6099 Mitsubishi M32R/D w/simulator m32r-*-elf*
6100 Tsqware Sparclet sparclet-*-*
6101 NEC V850 w/simulator v850-*-*
6103 * New debugging protocols
6105 ARM with RDI protocol arm*-*-*
6106 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6107 DDB and LSI variants of PMON protocol mips*-*-*
6108 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6109 PowerPC with SDS protocol powerpc{,le}-*-eabi
6110 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6114 All configurations can now understand and use the DWARF 2 debugging
6115 format. The choice is automatic, if the symbol file contains DWARF 2
6120 GDB now includes basic Java language support. This support is
6121 only useful with Java compilers that produce native machine code.
6123 * solib-absolute-prefix and solib-search-path
6125 For SunOS and SVR4 shared libraries, you may now set the prefix for
6126 loading absolute shared library symbol files, and the search path for
6127 locating non-absolute shared library symbol files.
6129 * Live range splitting
6131 GDB can now effectively debug code for which GCC has performed live
6132 range splitting as part of its optimization. See gdb/doc/LRS for
6133 more details on the expected format of the stabs information.
6137 GDB's support for the GNU Hurd, including thread debugging, has been
6138 updated to work with current versions of the Hurd.
6142 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6143 instruction set. ARM GDB automatically detects when Thumb
6144 instructions are in use, and adjusts disassembly and backtracing
6149 GDB's MIPS target configurations now handle the MIP16 16-bit
6154 GDB now includes support for overlays; if an executable has been
6155 linked such that multiple sections are based at the same address, GDB
6156 will decide which section to use for symbolic info. You can choose to
6157 control the decision manually, using overlay commands, or implement
6158 additional target-side support and use "overlay load-target" to bring
6159 in the overlay mapping. Do "help overlay" for more detail.
6163 The command "info symbol <address>" displays information about
6164 the symbol at the specified address.
6168 The standard remote protocol now includes an extension that allows
6169 asynchronous collection and display of trace data. This requires
6170 extensive support in the target-side debugging stub. Tracing mode
6171 includes a new interaction mode in GDB and new commands: see the
6172 file tracepoint.c for more details.
6176 Configurations for embedded MIPS now include a simulator contributed
6177 by Cygnus Solutions. The simulator supports the instruction sets
6178 of most MIPS variants.
6182 Sparc configurations may now include the ERC32 simulator contributed
6183 by the European Space Agency. The simulator is not built into
6184 Sparc targets by default; configure with --enable-sim to include it.
6188 For target configurations that may include multiple variants of a
6189 basic architecture (such as MIPS and SH), you may now set the
6190 architecture explicitly. "set arch" sets, "info arch" lists
6191 the possible architectures.
6193 *** Changes in GDB-4.16:
6195 * New native configurations
6197 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6198 M68K NetBSD m68k-*-netbsd*
6199 PowerPC AIX 4.x powerpc-*-aix*
6200 PowerPC MacOS powerpc-*-macos*
6201 PowerPC Windows NT powerpcle-*-cygwin32
6202 RS/6000 AIX 4.x rs6000-*-aix4*
6206 ARM with RDP protocol arm-*-*
6207 I960 with MON960 i960-*-coff
6208 MIPS VxWorks mips*-*-vxworks*
6209 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6210 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6212 Matra Sparclet sparclet-*-*
6216 The powerpc-eabi configuration now includes the PSIM simulator,
6217 contributed by Andrew Cagney, with assistance from Mike Meissner.
6218 PSIM is a very elaborate model of the PowerPC, including not only
6219 basic instruction set execution, but also details of execution unit
6220 performance and I/O hardware. See sim/ppc/README for more details.
6224 GDB now works with Solaris 2.5.
6226 * Windows 95/NT native
6228 GDB will now work as a native debugger on Windows 95 and Windows NT.
6229 To build it from source, you must use the "gnu-win32" environment,
6230 which uses a DLL to emulate enough of Unix to run the GNU tools.
6231 Further information, binaries, and sources are available at
6232 ftp.cygnus.com, under pub/gnu-win32.
6234 * dont-repeat command
6236 If a user-defined command includes the command `dont-repeat', then the
6237 command will not be repeated if the user just types return. This is
6238 useful if the command is time-consuming to run, so that accidental
6239 extra keystrokes don't run the same command many times.
6241 * Send break instead of ^C
6243 The standard remote protocol now includes an option to send a break
6244 rather than a ^C to the target in order to interrupt it. By default,
6245 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6247 * Remote protocol timeout
6249 The standard remote protocol includes a new variable `remotetimeout'
6250 that allows you to set the number of seconds before GDB gives up trying
6251 to read from the target. The default value is 2.
6253 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6255 By default GDB will automatically keep track of objects as they are
6256 loaded and unloaded by the dynamic linker. By using the command `set
6257 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6258 when shared library events occur, thus allowing you to set breakpoints
6259 in shared libraries which are explicitly loaded by the inferior.
6261 Note this feature does not work on hpux8. On hpux9 you must link
6262 /usr/lib/end.o into your program. This feature should work
6263 automatically on hpux10.
6265 * Irix 5.x hardware watchpoint support
6267 Irix 5 configurations now support the use of hardware watchpoints.
6269 * Mips protocol "SYN garbage limit"
6271 When debugging a Mips target using the `target mips' protocol, you
6272 may set the number of characters that GDB will ignore by setting
6273 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6274 every character. The default value is 1050.
6276 * Recording and replaying remote debug sessions
6278 If you set `remotelogfile' to the name of a file, gdb will write to it
6279 a recording of a remote debug session. This recording may then be
6280 replayed back to gdb using "gdbreplay". See gdbserver/README for
6281 details. This is useful when you have a problem with GDB while doing
6282 remote debugging; you can make a recording of the session and send it
6283 to someone else, who can then recreate the problem.
6285 * Speedups for remote debugging
6287 GDB includes speedups for downloading and stepping MIPS systems using
6288 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6289 and more efficient S-record downloading.
6291 * Memory use reductions and statistics collection
6293 GDB now uses less memory and reports statistics about memory usage.
6294 Try the `maint print statistics' command, for example.
6296 *** Changes in GDB-4.15:
6298 * Psymtabs for XCOFF
6300 The symbol reader for AIX GDB now uses partial symbol tables. This
6301 can greatly improve startup time, especially for large executables.
6303 * Remote targets use caching
6305 Remote targets now use a data cache to speed up communication with the
6306 remote side. The data cache could lead to incorrect results because
6307 it doesn't know about volatile variables, thus making it impossible to
6308 debug targets which use memory mapped I/O devices. `set remotecache
6309 off' turns the the data cache off.
6311 * Remote targets may have threads
6313 The standard remote protocol now includes support for multiple threads
6314 in the target system, using new protocol commands 'H' and 'T'. See
6315 gdb/remote.c for details.
6319 If GDB is configured with `--enable-netrom', then it will include
6320 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6321 acts as though it is a bank of ROM on the target board, but you can
6322 write into it over the network. GDB's support consists only of
6323 support for fast loading into the emulated ROM; to debug, you must use
6324 another protocol, such as standard remote protocol. The usual
6325 sequence is something like
6327 target nrom <netrom-hostname>
6329 target remote <netrom-hostname>:1235
6333 GDB now includes support for the Apple Macintosh, as a host only. It
6334 may be run as either an MPW tool or as a standalone application, and
6335 it can debug through the serial port. All the usual GDB commands are
6336 available, but to the target command, you must supply "serial" as the
6337 device type instead of "/dev/ttyXX". See mpw-README in the main
6338 directory for more information on how to build. The MPW configuration
6339 scripts */mpw-config.in support only a few targets, and only the
6340 mips-idt-ecoff target has been tested.
6344 GDB configuration now uses autoconf. This is not user-visible,
6345 but does simplify configuration and building.
6349 GDB now supports hpux10.
6351 *** Changes in GDB-4.14:
6353 * New native configurations
6355 x86 FreeBSD i[345]86-*-freebsd
6356 x86 NetBSD i[345]86-*-netbsd
6357 NS32k NetBSD ns32k-*-netbsd
6358 Sparc NetBSD sparc-*-netbsd
6362 A29K VxWorks a29k-*-vxworks
6363 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6364 CPU32 EST-300 emulator m68*-*-est*
6365 PowerPC ELF powerpc-*-elf
6368 * Alpha OSF/1 support for procfs
6370 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6371 possible to attach to running processes. As the mounting of the /proc
6372 filesystem is optional on the Alpha, GDB automatically determines
6373 the availability of /proc during startup. This can lead to problems
6374 if /proc is unmounted after GDB has been started.
6376 * Arguments to user-defined commands
6378 User commands may accept up to 10 arguments separated by whitespace.
6379 Arguments are accessed within the user command via $arg0..$arg9. A
6382 print $arg0 + $arg1 + $arg2
6384 To execute the command use:
6387 Defines the command "adder" which prints the sum of its three arguments.
6388 Note the arguments are text substitutions, so they may reference variables,
6389 use complex expressions, or even perform inferior function calls.
6391 * New `if' and `while' commands
6393 This makes it possible to write more sophisticated user-defined
6394 commands. Both commands take a single argument, which is the
6395 expression to evaluate, and must be followed by the commands to
6396 execute, one per line, if the expression is nonzero, the list being
6397 terminated by the word `end'. The `if' command list may include an
6398 `else' word, which causes the following commands to be executed only
6399 if the expression is zero.
6401 * Fortran source language mode
6403 GDB now includes partial support for Fortran 77. It will recognize
6404 Fortran programs and can evaluate a subset of Fortran expressions, but
6405 variables and functions may not be handled correctly. GDB will work
6406 with G77, but does not yet know much about symbols emitted by other
6409 * Better HPUX support
6411 Most debugging facilities now work on dynamic executables for HPPAs
6412 running hpux9 or later. You can attach to running dynamically linked
6413 processes, but by default the dynamic libraries will be read-only, so
6414 for instance you won't be able to put breakpoints in them. To change
6415 that behavior do the following before running the program:
6421 This will cause the libraries to be mapped private and read-write.
6422 To revert to the normal behavior, do this:
6428 You cannot set breakpoints or examine data in the library until after
6429 the library is loaded if the function/data symbols do not have
6432 GDB can now also read debug symbols produced by the HP C compiler on
6433 HPPAs (sorry, no C++, Fortran or 68k support).
6435 * Target byte order now dynamically selectable
6437 You can choose which byte order to use with a target system, via the
6438 commands "set endian big" and "set endian little", and you can see the
6439 current setting by using "show endian". You can also give the command
6440 "set endian auto", in which case GDB will use the byte order
6441 associated with the executable. Currently, only embedded MIPS
6442 configurations support dynamic selection of target byte order.
6444 * New DOS host serial code
6446 This version uses DPMI interrupts to handle buffered I/O, so you
6447 no longer need to run asynctsr when debugging boards connected to
6450 *** Changes in GDB-4.13:
6452 * New "complete" command
6454 This lists all the possible completions for the rest of the line, if it
6455 were to be given as a command itself. This is intended for use by emacs.
6457 * Trailing space optional in prompt
6459 "set prompt" no longer adds a space for you after the prompt you set. This
6460 allows you to set a prompt which ends in a space or one that does not.
6462 * Breakpoint hit counts
6464 "info break" now displays a count of the number of times the breakpoint
6465 has been hit. This is especially useful in conjunction with "ignore"; you
6466 can ignore a large number of breakpoint hits, look at the breakpoint info
6467 to see how many times the breakpoint was hit, then run again, ignoring one
6468 less than that number, and this will get you quickly to the last hit of
6471 * Ability to stop printing at NULL character
6473 "set print null-stop" will cause GDB to stop printing the characters of
6474 an array when the first NULL is encountered. This is useful when large
6475 arrays actually contain only short strings.
6477 * Shared library breakpoints
6479 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6480 breakpoints in shared libraries before the executable is run.
6482 * Hardware watchpoints
6484 There is a new hardware breakpoint for the watch command for sparclite
6485 targets. See gdb/sparclite/hw_breakpoint.note.
6487 Hardware watchpoints are also now supported under GNU/Linux.
6491 Annotations have been added. These are for use with graphical interfaces,
6492 and are still experimental. Currently only gdba.el uses these.
6494 * Improved Irix 5 support
6496 GDB now works properly with Irix 5.2.
6498 * Improved HPPA support
6500 GDB now works properly with the latest GCC and GAS.
6502 * New native configurations
6504 Sequent PTX4 i[34]86-sequent-ptx4
6505 HPPA running OSF/1 hppa*-*-osf*
6506 Atari TT running SVR4 m68*-*-sysv4*
6507 RS/6000 LynxOS rs6000-*-lynxos*
6511 OS/9000 i[34]86-*-os9k
6512 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6515 * Hitachi SH7000 and E7000-PC ICE support
6517 There is now support for communicating with the Hitachi E7000-PC ICE.
6518 This is available automatically when GDB is configured for the SH.
6522 As usual, a variety of small fixes and improvements, both generic
6523 and configuration-specific. See the ChangeLog for more detail.
6525 *** Changes in GDB-4.12:
6527 * Irix 5 is now supported
6531 GDB-4.12 on the HPPA has a number of changes which make it unable
6532 to debug the output from the currently released versions of GCC and
6533 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6534 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6535 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6538 *** Changes in GDB-4.11:
6540 * User visible changes:
6544 The "set remotedebug" option is now consistent between the mips remote
6545 target, remote targets using the gdb-specific protocol, UDI (AMD's
6546 debug protocol for the 29k) and the 88k bug monitor. It is now an
6547 integer specifying a debug level (normally 0 or 1, but 2 means more
6548 debugging info for the mips target).
6550 * DEC Alpha native support
6552 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6553 debug info, but GDB works fairly well with the DEC compiler and should
6554 work with a future GCC release. See the README file for a few
6555 Alpha-specific notes.
6557 * Preliminary thread implementation
6559 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6561 * LynxOS native and target support for 386
6563 This release has been hosted on LynxOS 2.2, and also can be configured
6564 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6567 * Improvements in C++ mangling/demangling.
6569 This release has much better g++ debugging, specifically in name
6570 mangling/demangling, virtual function calls, print virtual table,
6571 call methods, ...etc.
6573 *** Changes in GDB-4.10:
6575 * User visible changes:
6577 Remote debugging using the GDB-specific (`target remote') protocol now
6578 supports the `load' command. This is only useful if you have some
6579 other way of getting the stub to the target system, and you can put it
6580 somewhere in memory where it won't get clobbered by the download.
6582 Filename completion now works.
6584 When run under emacs mode, the "info line" command now causes the
6585 arrow to point to the line specified. Also, "info line" prints
6586 addresses in symbolic form (as well as hex).
6588 All vxworks based targets now support a user settable option, called
6589 vxworks-timeout. This option represents the number of seconds gdb
6590 should wait for responses to rpc's. You might want to use this if
6591 your vxworks target is, perhaps, a slow software simulator or happens
6592 to be on the far side of a thin network line.
6596 This release contains support for using a DEC alpha as a GDB host for
6597 cross debugging. Native alpha debugging is not supported yet.
6600 *** Changes in GDB-4.9:
6604 This is the first GDB release which is accompanied by a matching testsuite.
6605 The testsuite requires installation of dejagnu, which should be available
6606 via ftp from most sites that carry GNU software.
6610 'Cfront' style demangling has had its name changed to 'ARM' style, to
6611 emphasize that it was written from the specifications in the C++ Annotated
6612 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6613 disclaimers, it still generated too much confusion with users attempting to
6614 use gdb with AT&T cfront.
6618 GDB now uses a standard remote interface to a simulator library.
6619 So far, the library contains simulators for the Zilog Z8001/2, the
6620 Hitachi H8/300, H8/500 and Super-H.
6622 * New targets supported
6624 H8/300 simulator h8300-hitachi-hms or h8300hms
6625 H8/500 simulator h8500-hitachi-hms or h8500hms
6626 SH simulator sh-hitachi-hms or sh
6627 Z8000 simulator z8k-zilog-none or z8ksim
6628 IDT MIPS board over serial line mips-idt-ecoff
6630 Cross-debugging to GO32 targets is supported. It requires a custom
6631 version of the i386-stub.c module which is integrated with the
6632 GO32 memory extender.
6634 * New remote protocols
6636 MIPS remote debugging protocol.
6638 * New source languages supported
6640 This version includes preliminary support for Chill, a Pascal like language
6641 used by telecommunications companies. Chill support is also being integrated
6642 into the GNU compiler, but we don't know when it will be publically available.
6645 *** Changes in GDB-4.8:
6647 * HP Precision Architecture supported
6649 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6650 version of this support was available as a set of patches from the
6651 University of Utah. GDB does not support debugging of programs
6652 compiled with the HP compiler, because HP will not document their file
6653 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6654 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6656 Many problems in the preliminary version have been fixed.
6658 * Faster and better demangling
6660 We have improved template demangling and fixed numerous bugs in the GNU style
6661 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6662 character types (wchar_t) are now supported. Demangling of each symbol is now
6663 only done once, and is cached when the symbol table for a file is read in.
6664 This results in a small increase in memory usage for C programs, a moderate
6665 increase in memory usage for C++ programs, and a fantastic speedup in
6668 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6669 from the specifications in the Annotated Reference Manual, which AT&T's
6670 compiler does not actually implement.
6672 * G++ multiple inheritance compiler problem
6674 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6675 inheritance lattices was reworked to properly discover ambiguities. We
6676 recently found an example which causes this new algorithm to fail in a
6677 very subtle way, producing bad debug information for those classes.
6678 The file 'gcc.patch' (in this directory) can be applied to gcc to
6679 circumvent the problem. A future GCC release will contain a complete
6682 The previous G++ debug info problem (mentioned below for the gdb-4.7
6683 release) is fixed in gcc version 2.3.2.
6685 * Improved configure script
6687 The `configure' script will now attempt to guess your system type if
6688 you don't supply a host system type. The old scheme of supplying a
6689 host system triplet is preferable over using this. All the magic is
6690 done in the new `config.guess' script. Examine it for details.
6692 We have also brought our configure script much more in line with the FSF's
6693 version. It now supports the --with-xxx options. In particular,
6694 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6695 The resulting GDB will not be able to read arbitrary object file formats --
6696 only the format ``expected'' to be used on the configured target system.
6697 We hope to make this the default in a future release.
6699 * Documentation improvements
6701 There's new internal documentation on how to modify GDB, and how to
6702 produce clean changes to the code. We implore people to read it
6703 before submitting changes.
6705 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6706 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6707 `info' files are also provided. To build `info' files from scratch,
6708 you will need the latest `makeinfo' release, which will be available in
6709 a future texinfo-X.Y release.
6711 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6712 We're not sure exactly which versions have this problem, but it has
6713 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6714 or better. If that isn't possible, there is a patch in
6715 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6716 around this problem.
6720 GDB now supports array constants that can be used in expressions typed in by
6721 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6722 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6725 The new directory `gdb/sparclite' contains a program that demonstrates
6726 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6728 * New native hosts supported
6730 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6731 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6733 * New targets supported
6735 AMD 29k family via UDI a29k-amd-udi or udi29k
6737 * New file formats supported
6739 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6740 HPUX core files, and SCO 3.2v2 core files.
6744 Attaching to processes now works again; thanks for the many bug reports.
6746 We have also stomped on a bunch of core dumps caused by
6747 printf_filtered("%s") problems.
6749 We eliminated a copyright problem on the rpc and ptrace header files
6750 for VxWorks, which was discovered at the last minute during the 4.7
6751 release. You should now be able to build a VxWorks GDB.
6753 You can now interrupt gdb while an attached process is running. This
6754 will cause the attached process to stop, and give control back to GDB.
6756 We fixed problems caused by using too many file descriptors
6757 for reading symbols from object files and libraries. This was
6758 especially a problem for programs that used many (~100) shared
6761 The `step' command now only enters a subroutine if there is line number
6762 information for the subroutine. Otherwise it acts like the `next'
6763 command. Previously, `step' would enter subroutines if there was
6764 any debugging information about the routine. This avoids problems
6765 when using `cc -g1' on MIPS machines.
6767 * Internal improvements
6769 GDB's internal interfaces have been improved to make it easier to support
6770 debugging of multiple languages in the future.
6772 GDB now uses a common structure for symbol information internally.
6773 Minimal symbols (derived from linkage symbols in object files), partial
6774 symbols (from a quick scan of debug information), and full symbols
6775 contain a common subset of information, making it easier to write
6776 shared code that handles any of them.
6778 * New command line options
6780 We now accept --silent as an alias for --quiet.
6784 The memory-mapped-malloc library is now licensed under the GNU Library
6785 General Public License.
6787 *** Changes in GDB-4.7:
6789 * Host/native/target split
6791 GDB has had some major internal surgery to untangle the support for
6792 hosts and remote targets. Now, when you configure GDB for a remote
6793 target, it will no longer load in all of the support for debugging
6794 local programs on the host. When fully completed and tested, this will
6795 ensure that arbitrary host/target combinations are possible.
6797 The primary conceptual shift is to separate the non-portable code in
6798 GDB into three categories. Host specific code is required any time GDB
6799 is compiled on that host, regardless of the target. Target specific
6800 code relates to the peculiarities of the target, but can be compiled on
6801 any host. Native specific code is everything else: it can only be
6802 built when the host and target are the same system. Child process
6803 handling and core file support are two common `native' examples.
6805 GDB's use of /proc for controlling Unix child processes is now cleaner.
6806 It has been split out into a single module under the `target_ops' vector,
6807 plus two native-dependent functions for each system that uses /proc.
6809 * New hosts supported
6811 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6812 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6813 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6815 * New targets supported
6817 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6818 68030 and CPU32 m68030-*-*, m68332-*-*
6820 * New native hosts supported
6822 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6823 (386bsd is not well tested yet)
6824 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6826 * New file formats supported
6828 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6829 supports reading of `a.out.adobe' object files, which are an a.out
6830 format extended with minimal information about multiple sections.
6834 `show copying' is the same as the old `info copying'.
6835 `show warranty' is the same as `info warrantee'.
6836 These were renamed for consistency. The old commands continue to work.
6838 `info handle' is a new alias for `info signals'.
6840 You can now define pre-command hooks, which attach arbitrary command
6841 scripts to any command. The commands in the hook will be executed
6842 prior to the user's command. You can also create a hook which will be
6843 executed whenever the program stops. See gdb.texinfo.
6847 We now deal with Cfront style name mangling, and can even extract type
6848 info from mangled symbols. GDB can automatically figure out which
6849 symbol mangling style your C++ compiler uses.
6851 Calling of methods and virtual functions has been improved as well.
6855 The crash that occured when debugging Sun Ansi-C compiled binaries is
6856 fixed. This was due to mishandling of the extra N_SO stabs output
6859 We also finally got Ultrix 4.2 running in house, and fixed core file
6860 support, with help from a dozen people on the net.
6862 John M. Farrell discovered that the reason that single-stepping was so
6863 slow on all of the Mips based platforms (primarily SGI and DEC) was
6864 that we were trying to demangle and lookup a symbol used for internal
6865 purposes on every instruction that was being stepped through. Changing
6866 the name of that symbol so that it couldn't be mistaken for a C++
6867 mangled symbol sped things up a great deal.
6869 Rich Pixley sped up symbol lookups in general by getting much smarter
6870 about when C++ symbol mangling is necessary. This should make symbol
6871 completion (TAB on the command line) much faster. It's not as fast as
6872 we'd like, but it's significantly faster than gdb-4.6.
6876 A new user controllable variable 'call_scratch_address' can
6877 specify the location of a scratch area to be used when GDB
6878 calls a function in the target. This is necessary because the
6879 usual method of putting the scratch area on the stack does not work
6880 in systems that have separate instruction and data spaces.
6882 We integrated changes to support the 29k UDI (Universal Debugger
6883 Interface), but discovered at the last minute that we didn't have all
6884 of the appropriate copyright paperwork. We are working with AMD to
6885 resolve this, and hope to have it available soon.
6889 We have sped up the remote serial line protocol, especially for targets
6890 with lots of registers. It now supports a new `expedited status' ('T')
6891 message which can be used in place of the existing 'S' status message.
6892 This allows the remote stub to send only the registers that GDB
6893 needs to make a quick decision about single-stepping or conditional
6894 breakpoints, eliminating the need to fetch the entire register set for
6895 each instruction being stepped through.
6897 The GDB remote serial protocol now implements a write-through cache for
6898 registers, only re-reading the registers if the target has run.
6900 There is also a new remote serial stub for SPARC processors. You can
6901 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6902 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6903 processor with a serial port.
6907 Configure.in files have become much easier to read and modify. A new
6908 `table driven' format makes it more obvious what configurations are
6909 supported, and what files each one uses.
6913 There is a new opcodes library which will eventually contain all of the
6914 disassembly routines and opcode tables. At present, it only contains
6915 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6916 disassembler (binutils/objdump) to share these routines.
6918 The libiberty library is now copylefted under the GNU Library General
6919 Public License. This allows more liberal use, and was done so libg++
6920 can use it. This makes no difference to GDB, since the Library License
6921 grants all the rights from the General Public License.
6925 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6926 reference to the stabs symbol info used by the debugger. It is (as far
6927 as we know) the only published document on this fascinating topic. We
6928 encourage you to read it, compare it to the stabs information on your
6929 system, and send improvements on the document in general (to
6930 bug-gdb@prep.ai.mit.edu).
6932 And, of course, many bugs have been fixed.
6935 *** Changes in GDB-4.6:
6937 * Better support for C++ function names
6939 GDB now accepts as input the "demangled form" of C++ overloaded function
6940 names and member function names, and can do command completion on such names
6941 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6942 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6943 Make use of command completion, it is your friend.
6945 GDB also now accepts a variety of C++ mangled symbol formats. They are
6946 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6947 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6948 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6949 for the list of formats.
6951 * G++ symbol mangling problem
6953 Recent versions of gcc have a bug in how they emit debugging information for
6954 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6955 directory) can be applied to gcc to fix the problem. Alternatively, if you
6956 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6957 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6958 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6961 * New 'maintenance' command
6963 All of the commands related to hacking GDB internals have been moved out of
6964 the main command set, and now live behind the 'maintenance' command. This
6965 can also be abbreviated as 'mt'. The following changes were made:
6967 dump-me -> maintenance dump-me
6968 info all-breakpoints -> maintenance info breakpoints
6969 printmsyms -> maintenance print msyms
6970 printobjfiles -> maintenance print objfiles
6971 printpsyms -> maintenance print psymbols
6972 printsyms -> maintenance print symbols
6974 The following commands are new:
6976 maintenance demangle Call internal GDB demangler routine to
6977 demangle a C++ link name and prints the result.
6978 maintenance print type Print a type chain for a given symbol
6980 * Change to .gdbinit file processing
6982 We now read the $HOME/.gdbinit file before processing the argv arguments
6983 (e.g. reading symbol files or core files). This allows global parameters to
6984 be set, which will apply during the symbol reading. The ./.gdbinit is still
6985 read after argv processing.
6987 * New hosts supported
6989 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6991 GNU/Linux support i386-unknown-linux or linux
6993 We are also including code to support the HP/PA running BSD and HPUX. This
6994 is almost guaranteed not to work, as we didn't have time to test or build it
6995 for this release. We are including it so that the more adventurous (or
6996 masochistic) of you can play with it. We also had major problems with the
6997 fact that the compiler that we got from HP doesn't support the -g option.
7000 * New targets supported
7002 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7004 * More smarts about finding #include files
7006 GDB now remembers the compilation directory for all include files, and for
7007 all files from which C is generated (like yacc and lex sources). This
7008 greatly improves GDB's ability to find yacc/lex sources, and include files,
7009 especially if you are debugging your program from a directory different from
7010 the one that contains your sources.
7012 We also fixed a bug which caused difficulty with listing and setting
7013 breakpoints in include files which contain C code. (In the past, you had to
7014 try twice in order to list an include file that you hadn't looked at before.)
7016 * Interesting infernals change
7018 GDB now deals with arbitrary numbers of sections, where the symbols for each
7019 section must be relocated relative to that section's landing place in the
7020 target's address space. This work was needed to support ELF with embedded
7021 stabs used by Solaris-2.0.
7023 * Bug fixes (of course!)
7025 There have been loads of fixes for the following things:
7026 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7027 i960, stabs, DOS(GO32), procfs, etc...
7029 See the ChangeLog for details.
7031 *** Changes in GDB-4.5:
7033 * New machines supported (host and target)
7035 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7037 SGI Irix-4.x mips-sgi-irix4 or iris4
7039 * New malloc package
7041 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7042 Mmalloc is capable of handling mutiple heaps of memory. It is also
7043 capable of saving a heap to a file, and then mapping it back in later.
7044 This can be used to greatly speedup the startup of GDB by using a
7045 pre-parsed symbol table which lives in a mmalloc managed heap. For
7046 more details, please read mmalloc/mmalloc.texi.
7050 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7051 'help info proc' for details.
7053 * MIPS ecoff symbol table format
7055 The code that reads MIPS symbol table format is now supported on all hosts.
7056 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7059 * File name changes for MS-DOS
7061 Many files in the config directories have been renamed to make it easier to
7062 support GDB on MS-DOSe systems (which have very restrictive file name
7063 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7064 environment) is close to working but has some remaining problems. Note
7065 that debugging of DOS programs is not supported, due to limitations
7066 in the ``operating system'', but it can be used to host cross-debugging.
7068 * Cross byte order fixes
7070 Many fixes have been made to support cross debugging of Sparc and MIPS
7071 targets from hosts whose byte order differs.
7073 * New -mapped and -readnow options
7075 If memory-mapped files are available on your system through the 'mmap'
7076 system call, you can use the -mapped option on the `file' or
7077 `symbol-file' commands to cause GDB to write the symbols from your
7078 program into a reusable file. If the program you are debugging is
7079 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7080 Future GDB debugging sessions will notice the presence of this file,
7081 and will quickly map in symbol information from it, rather than reading
7082 the symbol table from the executable program. Using the '-mapped'
7083 option in a GDB `file' or `symbol-file' command has the same effect as
7084 starting GDB with the '-mapped' command-line option.
7086 You can cause GDB to read the entire symbol table immediately by using
7087 the '-readnow' option with any of the commands that load symbol table
7088 information (or on the GDB command line). This makes the command
7089 slower, but makes future operations faster.
7091 The -mapped and -readnow options are typically combined in order to
7092 build a `fred.syms' file that contains complete symbol information.
7093 A simple GDB invocation to do nothing but build a `.syms' file for future
7096 gdb -batch -nx -mapped -readnow programname
7098 The `.syms' file is specific to the host machine on which GDB is run.
7099 It holds an exact image of GDB's internal symbol table. It cannot be
7100 shared across multiple host platforms.
7102 * longjmp() handling
7104 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7105 siglongjmp() without losing control. This feature has not yet been ported to
7106 all systems. It currently works on many 386 platforms, all MIPS-based
7107 platforms (SGI, DECstation, etc), and Sun3/4.
7111 Preliminary work has been put in to support the new Solaris OS from Sun. At
7112 this time, it can control and debug processes, but it is not capable of
7117 As always, many many bug fixes. The major areas were with g++, and mipsread.
7118 People using the MIPS-based platforms should experience fewer mysterious
7119 crashes and trashed symbol tables.
7121 *** Changes in GDB-4.4:
7123 * New machines supported (host and target)
7125 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7127 BSD Reno on Vax vax-dec-bsd
7128 Ultrix on Vax vax-dec-ultrix
7130 * New machines supported (target)
7132 AMD 29000 embedded, using EBMON a29k-none-none
7136 GDB continues to improve its handling of C++. `References' work better.
7137 The demangler has also been improved, and now deals with symbols mangled as
7138 per the Annotated C++ Reference Guide.
7140 GDB also now handles `stabs' symbol information embedded in MIPS
7141 `ecoff' symbol tables. Since the ecoff format was not easily
7142 extensible to handle new languages such as C++, this appeared to be a
7143 good way to put C++ debugging info into MIPS binaries. This option
7144 will be supported in the GNU C compiler, version 2, when it is
7147 * New features for SVR4
7149 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7150 shared libraries. Debugging dynamically linked programs should present
7151 only minor differences from debugging statically linked programs.
7153 The `info proc' command will print out information about any process
7154 on an SVR4 system (including the one you are debugging). At the moment,
7155 it prints the address mappings of the process.
7157 If you bring up GDB on another SVR4 system, please send mail to
7158 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7160 * Better dynamic linking support in SunOS
7162 Reading symbols from shared libraries which contain debugging symbols
7163 now works properly. However, there remain issues such as automatic
7164 skipping of `transfer vector' code during function calls, which
7165 make it harder to debug code in a shared library, than to debug the
7166 same code linked statically.
7170 GDB is now using the latest `getopt' routines from the FSF. This
7171 version accepts the -- prefix for options with long names. GDB will
7172 continue to accept the old forms (-option and +option) as well.
7173 Various single letter abbreviations for options have been explicity
7174 added to the option table so that they won't get overshadowed in the
7175 future by other options that begin with the same letter.
7179 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7180 Many assorted bugs have been handled. Many more remain to be handled.
7181 See the various ChangeLog files (primarily in gdb and bfd) for details.
7184 *** Changes in GDB-4.3:
7186 * New machines supported (host and target)
7188 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7189 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7190 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7192 * Almost SCO Unix support
7194 We had hoped to support:
7195 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7196 (except for core file support), but we discovered very late in the release
7197 that it has problems with process groups that render gdb unusable. Sorry
7198 about that. I encourage people to fix it and post the fixes.
7200 * Preliminary ELF and DWARF support
7202 GDB can read ELF object files on System V Release 4, and can handle
7203 debugging records for C, in DWARF format, in ELF files. This support
7204 is preliminary. If you bring up GDB on another SVR4 system, please
7205 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7210 GDB now uses the latest `readline' library. One user-visible change
7211 is that two tabs will list possible command completions, which previously
7212 required typing M-? (meta-question mark, or ESC ?).
7216 The `stepi' bug that many of you noticed has been squashed.
7217 Many bugs in C++ have been handled. Many more remain to be handled.
7218 See the various ChangeLog files (primarily in gdb and bfd) for details.
7220 * State of the MIPS world (in case you wondered):
7222 GDB can understand the symbol tables emitted by the compilers
7223 supplied by most vendors of MIPS-based machines, including DEC. These
7224 symbol tables are in a format that essentially nobody else uses.
7226 Some versions of gcc come with an assembler post-processor called
7227 mips-tfile. This program is required if you want to do source-level
7228 debugging of gcc-compiled programs. I believe FSF does not ship
7229 mips-tfile with gcc version 1, but it will eventually come with gcc
7232 Debugging of g++ output remains a problem. g++ version 1.xx does not
7233 really support it at all. (If you're lucky, you should be able to get
7234 line numbers and stack traces to work, but no parameters or local
7235 variables.) With some work it should be possible to improve the
7238 When gcc version 2 is released, you will have somewhat better luck.
7239 However, even then you will get confusing results for inheritance and
7242 We will eventually provide full debugging of g++ output on
7243 DECstations. This will probably involve some kind of stabs-in-ecoff
7244 encapulation, but the details have not been worked out yet.
7247 *** Changes in GDB-4.2:
7249 * Improved configuration
7251 Only one copy of `configure' exists now, and it is not self-modifying.
7252 Porting BFD is simpler.
7256 The `step' and `next' commands now only stop at the first instruction
7257 of a source line. This prevents the multiple stops that used to occur
7258 in switch statements, for-loops, etc. `Step' continues to stop if a
7259 function that has debugging information is called within the line.
7263 Lots of small bugs fixed. More remain.
7265 * New host supported (not target)
7267 Intel 386 PC clone running Mach i386-none-mach
7270 *** Changes in GDB-4.1:
7272 * Multiple source language support
7274 GDB now has internal scaffolding to handle several source languages.
7275 It determines the type of each source file from its filename extension,
7276 and will switch expression parsing and number formatting to match the
7277 language of the function in the currently selected stack frame.
7278 You can also specifically set the language to be used, with
7279 `set language c' or `set language modula-2'.
7283 GDB now has preliminary support for the GNU Modula-2 compiler,
7284 currently under development at the State University of New York at
7285 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7286 continue through the fall of 1991 and into 1992.
7288 Other Modula-2 compilers are currently not supported, and attempting to
7289 debug programs compiled with them will likely result in an error as the
7290 symbol table is read. Feel free to work on it, though!
7292 There are hooks in GDB for strict type checking and range checking,
7293 in the `Modula-2 philosophy', but they do not currently work.
7297 GDB can now write to executable and core files (e.g. patch
7298 a variable's value). You must turn this switch on, specify
7299 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7300 by assigning a new value to a variable. Modifications take
7303 * Automatic SunOS shared library reading
7305 When you run your program, GDB automatically determines where its
7306 shared libraries (if any) have been loaded, and reads their symbols.
7307 The `share' command is no longer needed. This also works when
7308 examining core files.
7312 You can specify the number of lines that the `list' command shows.
7315 * New machines supported (host and target)
7317 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7318 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7319 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7321 * New hosts supported (not targets)
7323 IBM RT/PC: romp-ibm-aix or rtpc
7325 * New targets supported (not hosts)
7327 AMD 29000 embedded with COFF a29k-none-coff
7328 AMD 29000 embedded with a.out a29k-none-aout
7329 Ultracomputer remote kernel debug a29k-nyu-kern
7331 * New remote interfaces
7337 *** Changes in GDB-4.0:
7341 Wide output is wrapped at good places to make the output more readable.
7343 Gdb now supports cross-debugging from a host machine of one type to a
7344 target machine of another type. Communication with the target system
7345 is over serial lines. The ``target'' command handles connecting to the
7346 remote system; the ``load'' command will download a program into the
7347 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7348 also supports debugging of realtime processes running under VxWorks,
7349 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7350 stub on the target system.
7352 New CPUs supported include the AMD 29000 and Intel 960.
7354 GDB now reads object files and symbol tables via a ``binary file''
7355 library, which allows a single copy of GDB to debug programs of multiple
7356 object file types such as a.out and coff.
7358 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7359 refcard.dvi and refcard.ps are available to format it).
7362 * Control-Variable user interface simplified
7364 All variables that control the operation of the debugger can be set
7365 by the ``set'' command, and displayed by the ``show'' command.
7367 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7368 ``Show prompt'' produces the response:
7369 Gdb's prompt is new-gdb=>.
7371 What follows are the NEW set commands. The command ``help set'' will
7372 print a complete list of old and new set commands. ``help set FOO''
7373 will give a longer description of the variable FOO. ``show'' will show
7374 all of the variable descriptions and their current settings.
7376 confirm on/off: Enables warning questions for operations that are
7377 hard to recover from, e.g. rerunning the program while
7378 it is already running. Default is ON.
7380 editing on/off: Enables EMACS style command line editing
7381 of input. Previous lines can be recalled with
7382 control-P, the current line can be edited with control-B,
7383 you can search for commands with control-R, etc.
7386 history filename NAME: NAME is where the gdb command history
7387 will be stored. The default is .gdb_history,
7388 or the value of the environment variable
7391 history size N: The size, in commands, of the command history. The
7392 default is 256, or the value of the environment variable
7395 history save on/off: If this value is set to ON, the history file will
7396 be saved after exiting gdb. If set to OFF, the
7397 file will not be saved. The default is OFF.
7399 history expansion on/off: If this value is set to ON, then csh-like
7400 history expansion will be performed on
7401 command line input. The default is OFF.
7403 radix N: Sets the default radix for input and output. It can be set
7404 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7405 in the current radix, so "set radix 10" is always a no-op.
7407 height N: This integer value is the number of lines on a page. Default
7408 is 24, the current `stty rows'' setting, or the ``li#''
7409 setting from the termcap entry matching the environment
7412 width N: This integer value is the number of characters on a line.
7413 Default is 80, the current `stty cols'' setting, or the ``co#''
7414 setting from the termcap entry matching the environment
7417 Note: ``set screensize'' is obsolete. Use ``set height'' and
7418 ``set width'' instead.
7420 print address on/off: Print memory addresses in various command displays,
7421 such as stack traces and structure values. Gdb looks
7422 more ``symbolic'' if you turn this off; it looks more
7423 ``machine level'' with it on. Default is ON.
7425 print array on/off: Prettyprint arrays. New convenient format! Default
7428 print demangle on/off: Print C++ symbols in "source" form if on,
7431 print asm-demangle on/off: Same, for assembler level printouts
7434 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7437 * Support for Epoch Environment.
7439 The epoch environment is a version of Emacs v18 with windowing. One
7440 new command, ``inspect'', is identical to ``print'', except that if you
7441 are running in the epoch environment, the value is printed in its own
7445 * Support for Shared Libraries
7447 GDB can now debug programs and core files that use SunOS shared libraries.
7448 Symbols from a shared library cannot be referenced
7449 before the shared library has been linked with the program (this
7450 happens after you type ``run'' and before the function main() is entered).
7451 At any time after this linking (including when examining core files
7452 from dynamically linked programs), gdb reads the symbols from each
7453 shared library when you type the ``sharedlibrary'' command.
7454 It can be abbreviated ``share''.
7456 sharedlibrary REGEXP: Load shared object library symbols for files
7457 matching a unix regular expression. No argument
7458 indicates to load symbols for all shared libraries.
7460 info sharedlibrary: Status of loaded shared libraries.
7465 A watchpoint stops execution of a program whenever the value of an
7466 expression changes. Checking for this slows down execution
7467 tremendously whenever you are in the scope of the expression, but is
7468 quite useful for catching tough ``bit-spreader'' or pointer misuse
7469 problems. Some machines such as the 386 have hardware for doing this
7470 more quickly, and future versions of gdb will use this hardware.
7472 watch EXP: Set a watchpoint (breakpoint) for an expression.
7474 info watchpoints: Information about your watchpoints.
7476 delete N: Deletes watchpoint number N (same as breakpoints).
7477 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7478 enable N: Re-enables watchpoint number N (same as breakpoints).
7481 * C++ multiple inheritance
7483 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7486 * C++ exception handling
7488 Gdb now supports limited C++ exception handling. Besides the existing
7489 ability to breakpoint on an exception handler, gdb can breakpoint on
7490 the raising of an exception (before the stack is peeled back to the
7493 catch FOO: If there is a FOO exception handler in the dynamic scope,
7494 set a breakpoint to catch exceptions which may be raised there.
7495 Multiple exceptions (``catch foo bar baz'') may be caught.
7497 info catch: Lists all exceptions which may be caught in the
7498 current stack frame.
7501 * Minor command changes
7503 The command ``call func (arg, arg, ...)'' now acts like the print
7504 command, except it does not print or save a value if the function's result
7505 is void. This is similar to dbx usage.
7507 The ``up'' and ``down'' commands now always print the frame they end up
7508 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7509 frames without printing.
7511 * New directory command
7513 'dir' now adds directories to the FRONT of the source search path.
7514 The path starts off empty. Source files that contain debug information
7515 about the directory in which they were compiled can be found even
7516 with an empty path; Sun CC and GCC include this information. If GDB can't
7517 find your source file in the current directory, type "dir .".
7519 * Configuring GDB for compilation
7521 For normal use, type ``./configure host''. See README or gdb.texinfo
7524 GDB now handles cross debugging. If you are remotely debugging between
7525 two different machines, type ``./configure host -target=targ''.
7526 Host is the machine where GDB will run; targ is the machine
7527 where the program that you are debugging will run.