1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.3
6 * 'thread-exited' event is now available in the annotations interface.
8 * New built-in convenience variables $_gdb_major and $_gdb_minor
9 provide the GDB version. They are handy for conditionally using
10 features available only in or since specific GDB versions, in
11 scripts that should work error-free with many different versions,
12 such as in system-wide init files.
14 * GDB now supports Thread Local Storage (TLS) variables on several
15 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
16 architectures require kernel changes. TLS is not yet supported for
17 amd64 and i386 process core dumps.
19 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
20 addresses that required unmasking are shown in the backtrace with the
23 * Two new convenience functions $_cimag and $_creal that extract the
24 imaginary and real parts respectively from complex numbers.
26 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
27 provide the exitcode or exit status of the shell commands launched by
28 GDB commands such as "shell", "pipe" and "make".
30 * The RX port now supports XML target descriptions.
34 ** The gdb.Value type has a new method 'format_string' which returns a
35 string representing the value. The formatting is controlled by the
36 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
37 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
38 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
40 ** gdb.Type has a new property 'objfile' which returns the objfile the
43 ** The frame information printed by the python frame filtering code
44 is now consistent with what the 'backtrace' command prints when
45 there are no filters, or when the 'backtrace' '-no-filters' option
48 ** The new function gdb.lookup_static_symbol can be used to look up
49 symbols with static linkage.
51 ** gdb.Objfile has new methods 'lookup_global_symbol' and
52 'lookup_static_symbol' to lookup a symbol from this objfile only.
54 ** gdb.Block now supports the dictionary syntax for accessing symbols in
55 this block (e.g. block['local_variable']).
59 | [COMMAND] | SHELL_COMMAND
60 | -d DELIM COMMAND DELIM SHELL_COMMAND
61 pipe [COMMAND] | SHELL_COMMAND
62 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
63 Executes COMMAND and sends its output to SHELL_COMMAND.
64 With no COMMAND, repeat the last executed command
65 and send its output to SHELL_COMMAND.
67 with SETTING [VALUE] [-- COMMAND]
68 w SETTING [VALUE] [-- COMMAND]
69 Temporarily set SETTING, run COMMAND, and restore SETTING.
70 Usage: with SETTING -- COMMAND
71 With no COMMAND, repeats the last executed command.
72 SETTING is any GDB setting you can change with the "set"
73 subcommands. For example, 'with language c -- print someobj'
74 temporarily switches to the C language in order to print someobj.
75 Settings can be combined: 'w lang c -- w print elements unlimited --
76 usercmd' switches to the C language and runs usercmd with no limit
77 of array elements to print.
79 maint with SETTING [VALUE] [-- COMMAND]
80 Like "with", but works with "maintenance set" settings.
82 set may-call-functions [on|off]
83 show may-call-functions
84 This controls whether GDB will attempt to call functions in
85 the program, such as with expressions in the print command. It
86 defaults to on. Calling functions in the program being debugged
87 can have undesired side effects. It is now possible to forbid
88 such function calls. If function calls are forbidden, GDB will throw
89 an error when a command (such as print expression) calls a function
92 set print finish [on|off]
94 This controls whether the `finish' command will display the value
95 that is returned by the current function. When `off', the value is
96 still entered into the value history, but it is not printed. The
101 Allows deeply nested structures to be simplified when printing by
102 replacing deeply nested parts (beyond the max-depth) with ellipses.
103 The default max-depth is 20, but this can be set to unlimited to get
104 the old behavior back.
106 set logging debugredirect [on|off]
107 By default, GDB debug output will go to both the terminal and the logfile.
108 Set if you want debug output to go only to the log file.
110 set style title foreground COLOR
111 set style title background COLOR
112 set style title intensity VALUE
113 Control the styling of titles.
115 set style highlight foreground COLOR
116 set style highlight background COLOR
117 set style highlight intensity VALUE
118 Control the styling of highlightings.
120 maint set test-settings KIND
121 maint show test-settings KIND
122 A set of commands used by the testsuite for exercising the settings
125 set print frame-info [short-location|location|location-and-address
126 |source-and-location|source-line|auto]
127 show print frame-info
128 This controls what frame information is printed by the commands printing
129 a frame. This setting will e.g. influence the behaviour of 'backtrace',
130 'frame', 'stepi'. The python frame filtering also respect this setting.
131 The 'backtrace' '-frame-info' option can override this global setting.
136 The "help" command uses the title style to enhance the
137 readibility of its output by styling the classes and
141 Similarly to "help", the "apropos" command also uses the
142 title style for the command names. "apropos" accepts now
143 a flag "-v" (verbose) to show the full documentation
144 of matching commands and to use the highlight style to mark
145 the documentation parts matching REGEXP.
149 The GDB printf and eval commands can now print C-style and Ada-style
150 string convenience variables without calling functions in the program.
151 This allows to do formatted printing of strings without having
152 a running inferior, or when debugging a core dump.
154 info sources [-dirname | -basename] [--] [REGEXP]
155 This command has now optional arguments to only print the files
156 whose names match REGEXP. The arguments -dirname and -basename
157 allow to restrict matching respectively to the dirname and basename
161 The "show style" and its subcommands are now styling
162 a style name in their output using its own style, to help
163 the user visualize the different styles.
165 set print frame-arguments
166 The new value 'presence' indicates to only indicate the presence of
167 arguments using ..., instead of printing argument names and values.
169 set print raw-frame-arguments
170 show print raw-frame-arguments
172 These commands replace the similarly-named "set/show print raw
173 frame-arguments" commands (now with a dash instead of a space). The
174 old commands are now deprecated and may be removed in a future
177 maint test-options require-delimiter
178 maint test-options unknown-is-error
179 maint test-options unknown-is-operand
180 maint show test-options-completion-result
181 Commands used by the testsuite to validate the command options
184 * New command options, command completion
186 GDB now has a standard infrastructure to support dash-style command
187 options ('-OPT'). One benefit is that commands that use it can
188 easily support completion of command line arguments. Try "CMD
189 -[TAB]" or "help CMD" to find options supported by a command. Over
190 time, we intend to migrate most commands to this infrastructure. A
191 number of commands got support for new command options in this
194 ** The "print" and "compile print" commands now support a number of
195 options that allow overriding relevant global print settings as
196 set by "set print" subcommands:
200 -array-indexes [on|off]
201 -elements NUMBER|unlimited
205 -repeats NUMBER|unlimited
206 -static-members [on|off]
211 Note that because the "print"/"compile print" commands accept
212 arbitrary expressions which may look like options (including
213 abbreviations), if you specify any command option, then you must
214 use a double dash ("--") to mark the end of argument processing.
216 ** The "backtrace" command now supports a number of options that
217 allow overriding relevant global print settings as set by "set
218 backtrace" and "set print" subcommands:
220 -entry-values no|only|preferred|if-needed|both|compact|default
221 -frame-arguments all|scalars|none
222 -raw-frame-arguments [on|off]
223 -frame-info auto|source-line|location|source-and-location
224 |location-and-address|short-location
228 In addition, the full/no-filters/hide qualifiers are now also
229 exposed as command options too:
235 ** The "frame apply", "tfaas" and "faas" commands similarly now
236 support the following options:
241 ** The new "info sources" options -dirname and -basename options
242 are using the standard '-OPT' infrastructure.
244 All options above can also be abbreviated. The argument of boolean
245 (on/off) options can be 0/1 too, and also the argument is assumed
246 "on" if omitted. This allows writing compact command invocations,
249 (gdb) p -r -p -o 0 -- *myptr
251 The above is equivalent to:
253 (gdb) print -raw -pretty -object off -- *myptr
255 ** The "info types" command now supports the '-q' flag to disable
256 printing of some header information in a similar fashion to "info
257 variables" and "info functions".
259 * Completion improvements
261 ** GDB can now complete the options of the "thread apply all" and
262 "taas" commands, and their "-ascending" option can now be
265 ** GDB can now complete the options of the "info threads", "info
266 functions", "info variables", "info locals", and "info args"
269 ** GDB can now complete the options of the "compile file" and
270 "compile code" commands. The "compile file" command now
271 completes on filenames.
273 ** GDB can now complete the backtrace command's
274 "full/no-filters/hide" qualifiers.
276 * In settings, you can now abbreviate "unlimited".
278 E.g., "set print elements u" is now equivalent to "set print
284 This lists all the possible completions for the rest of the line, if it
285 were to be given as a command itself. This is intended for use by MI
286 frontends in cases when separate CLI and MI channels cannot be used.
288 -catch-throw, -catch-rethrow, and -catch-catch
289 These can be used to catch C++ exceptions in a similar fashion to
290 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
294 ** Backtraces and frames include a new optional field addr_flags which is
295 given after the addr field. On AArch64 this contains PAC if the address
296 has been masked in the frame. On all other targets the field is not
301 The testsuite now creates the files gdb.cmd (containing the arguments
302 used to launch GDB) and gdb.in (containing all the commands sent to
303 GDB) in the output directory for each test script. Multiple invocations
304 are appended with .1, .2, .3 etc.
306 * Building GDB and GDBserver now requires GNU make >= 3.82.
308 Using another implementation of the make program or an earlier version of
309 GNU make to build GDB or GDBserver is not supported.
311 * Building GDB now requires GNU readline >= 7.0.
313 GDB now bundles GNU readline 8.0, but if you choose to use
314 --with-system-readline, only readline >= 7.0 can be used.
316 *** Changes in GDB 8.3
318 * GDB and GDBserver now support access to additional registers on
319 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
322 * GDB now has experimental support for the compilation and injection of
323 C++ source code into the inferior. This beta release does not include
324 support for several language features, such as templates, constructors,
327 This feature requires GCC 7.1 or higher built with libcp1.so
330 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
331 can be passed using the '[ADDRESS]:PORT' notation, or the regular
332 'ADDRESS:PORT' method.
334 * DWARF index cache: GDB can now automatically save indices of DWARF
335 symbols on disk to speed up further loading of the same binaries.
337 * Ada task switching is now supported on aarch64-elf targets when
338 debugging a program using the Ravenscar Profile. For more information,
339 see the "Tasking Support when using the Ravenscar Profile" section
340 in the GDB user manual.
342 * GDB in batch mode now exits with status 1 if the last command to be
345 * The RISC-V target now supports target descriptions.
347 * System call catchpoints now support system call aliases on FreeBSD.
348 When the ABI of a system call changes in FreeBSD, this is
349 implemented by leaving a compatibility system call using the old ABI
350 at the existing number and allocating a new system call number for
351 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
352 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
353 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
354 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
355 so that a system call catchpoint for the 'kevent' system call will
356 catch invocations of both the 'kevent' and 'freebsd11_kevent'
357 binaries. This ensures that 'kevent' system calls are caught for
358 binaries using either the old or new ABIs.
360 * Terminal styling is now available for the CLI and the TUI. GNU
361 Source Highlight can additionally be used to provide styling of
362 source code snippets. See the "set style" commands, below, for more
365 * Removed support for old demangling styles arm, edg, gnu, hp and
370 set debug compile-cplus-types
371 show debug compile-cplus-types
372 Control the display of debug output about type conversion in the
373 C++ compile feature. Commands have no effect while compiliong
378 Control whether debug output about files/functions skipping is
381 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
382 Apply a command to some frames.
383 FLAG arguments allow to control what output to produce and how to handle
384 errors raised when applying COMMAND to a frame.
387 Apply a command to all threads (ignoring errors and empty output).
388 Shortcut for 'thread apply all -s COMMAND'.
391 Apply a command to all frames (ignoring errors and empty output).
392 Shortcut for 'frame apply all -s COMMAND'.
395 Apply a command to all frames of all threads (ignoring errors and empty
397 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
399 maint set dwarf unwinders (on|off)
400 maint show dwarf unwinders
401 Control whether DWARF unwinders can be used.
404 Display a list of open files for a process.
408 Changes to the "frame", "select-frame", and "info frame" CLI commands.
409 These commands all now take a frame specification which
410 is either a frame level, or one of the keywords 'level', 'address',
411 'function', or 'view' followed by a parameter. Selecting a frame by
412 address, or viewing a frame outside the current backtrace now
413 requires the use of a keyword. Selecting a frame by level is
414 unchanged. The MI comment "-stack-select-frame" is unchanged.
416 target remote FILENAME
417 target extended-remote FILENAME
418 If FILENAME is a Unix domain socket, GDB will attempt to connect
419 to this socket instead of opening FILENAME as a character device.
421 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
422 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
423 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
424 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
425 These commands can now print only the searched entities
426 matching the provided regexp(s), giving a condition
427 on the entity names or entity types. The flag -q disables
428 printing headers or informations messages.
434 These commands now determine the syntax for the shown entities
435 according to the language chosen by `set language'. In particular,
436 `set language auto' means to automatically choose the language of
439 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
440 The 'thread apply' command accepts new FLAG arguments.
441 FLAG arguments allow to control what output to produce and how to handle
442 errors raised when applying COMMAND to a thread.
444 set tui tab-width NCHARS
445 show tui tab-width NCHARS
446 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
448 set style enabled [on|off]
450 Enable or disable terminal styling. Styling is enabled by default
451 on most hosts, but disabled by default when in batch mode.
453 set style sources [on|off]
455 Enable or disable source code styling. Source code styling is
456 enabled by default, but only takes effect if styling in general is
457 enabled, and if GDB was linked with GNU Source Highlight.
459 set style filename foreground COLOR
460 set style filename background COLOR
461 set style filename intensity VALUE
462 Control the styling of file names.
464 set style function foreground COLOR
465 set style function background COLOR
466 set style function intensity VALUE
467 Control the styling of function names.
469 set style variable foreground COLOR
470 set style variable background COLOR
471 set style variable intensity VALUE
472 Control the styling of variable names.
474 set style address foreground COLOR
475 set style address background COLOR
476 set style address intensity VALUE
477 Control the styling of addresses.
481 ** The default version of the MI interpreter is now 3 (-i=mi3).
483 ** The '-data-disassemble' MI command now accepts an '-a' option to
484 disassemble the whole function surrounding the given program
485 counter value or function name. Support for this feature can be
486 verified by using the "-list-features" command, which should
487 contain "data-disassemble-a-option".
489 ** Command responses and notifications that include a frame now include
490 the frame's architecture in a new "arch" attribute.
492 ** The output of information about multi-location breakpoints (which is
493 syntactically incorrect in MI 2) has changed in MI 3. This affects
494 the following commands and events:
498 - =breakpoint-created
499 - =breakpoint-modified
501 The -fix-multi-location-breakpoint-output command can be used to enable
502 this behavior with previous MI versions.
504 * New native configurations
506 GNU/Linux/RISC-V riscv*-*-linux*
507 FreeBSD/riscv riscv*-*-freebsd*
511 GNU/Linux/RISC-V riscv*-*-linux*
513 CSKY GNU/LINUX csky*-*-linux
514 FreeBSD/riscv riscv*-*-freebsd*
516 GNU/Linux/OpenRISC or1k*-*-linux*
520 GDB no longer supports native debugging on versions of MS-Windows
525 ** GDB no longer supports Python versions less than 2.6.
527 ** The gdb.Inferior type has a new 'progspace' property, which is the program
528 space associated to that inferior.
530 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
531 of objfiles associated to that program space.
533 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
534 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
537 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
538 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
539 correct and did not work properly.
541 ** The gdb.Value type has a new constructor, which is used to construct a
542 gdb.Value from a Python buffer object and a gdb.Type.
548 Enable or disable the undefined behavior sanitizer. This is
549 disabled by default, but passing --enable-ubsan=yes or
550 --enable-ubsan=auto to configure will enable it. Enabling this can
551 cause a performance penalty. The undefined behavior sanitizer was
552 first introduced in GCC 4.9.
554 *** Changes in GDB 8.2
556 * The 'set disassembler-options' command now supports specifying options
559 * The 'symbol-file' command now accepts an '-o' option to add a relative
560 offset to all sections.
562 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
563 a relative offset to all sections, but it allows to override the load
564 address of individual sections using '-s'.
566 * The 'add-symbol-file' command no longer requires the second argument
567 (address of the text section).
569 * The endianness used with the 'set endian auto' mode in the absence of
570 an executable selected for debugging is now the last endianness chosen
571 either by one of the 'set endian big' and 'set endian little' commands
572 or by inferring from the last executable used, rather than the startup
575 * The pager now allows a "c" response, meaning to disable the pager
576 for the rest of the current command.
578 * The commands 'info variables/functions/types' now show the source line
579 numbers of symbol definitions when available.
581 * 'info proc' now works on running processes on FreeBSD systems and core
582 files created on FreeBSD systems.
584 * C expressions can now use _Alignof, and C++ expressions can now use
587 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
588 the vector length while the process is running.
594 Control display of debugging info regarding the FreeBSD native target.
596 set|show varsize-limit
597 This new setting allows the user to control the maximum size of Ada
598 objects being printed when those objects have a variable type,
599 instead of that maximum size being hardcoded to 65536 bytes.
601 set|show record btrace cpu
602 Controls the processor to be used for enabling errata workarounds for
605 maint check libthread-db
606 Run integrity checks on the current inferior's thread debugging
609 maint set check-libthread-db (on|off)
610 maint show check-libthread-db
611 Control whether to run integrity checks on inferior specific thread
612 debugging libraries as they are loaded. The default is not to
617 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
619 ** The commands attached to a breakpoint can be set by assigning to
620 the breakpoint's "commands" field.
622 ** gdb.execute can now execute multi-line gdb commands.
624 ** The new functions gdb.convenience_variable and
625 gdb.set_convenience_variable can be used to get and set the value
626 of convenience variables.
628 ** A gdb.Parameter will no longer print the "set" help text on an
629 ordinary "set"; instead by default a "set" will be silent unless
630 the get_set_string method returns a non-empty string.
634 RiscV ELF riscv*-*-elf
636 * Removed targets and native configurations
638 m88k running OpenBSD m88*-*-openbsd*
639 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
640 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
641 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
643 * Aarch64/Linux hardware watchpoints improvements
645 Hardware watchpoints on unaligned addresses are now properly
646 supported when running Linux kernel 4.10 or higher: read and access
647 watchpoints are no longer spuriously missed, and all watchpoints
648 lengths between 1 and 8 bytes are supported. On older kernels,
649 watchpoints set on unaligned addresses are no longer missed, with
650 the tradeoff that there is a possibility of false hits being
655 --enable-codesign=CERT
656 This can be used to invoke "codesign -s CERT" after building gdb.
657 This option is useful on macOS, where code signing is required for
658 gdb to work properly.
660 --disable-gdbcli has been removed
661 This is now silently accepted, but does nothing.
663 *** Changes in GDB 8.1
665 * GDB now supports dynamically creating arbitrary register groups specified
666 in XML target descriptions. This allows for finer grain grouping of
667 registers on systems with a large amount of registers.
669 * The 'ptype' command now accepts a '/o' flag, which prints the
670 offsets and sizes of fields in a struct, like the pahole(1) tool.
672 * New "--readnever" command line option instructs GDB to not read each
673 symbol file's symbolic debug information. This makes startup faster
674 but at the expense of not being able to perform symbolic debugging.
675 This option is intended for use cases where symbolic debugging will
676 not be used, e.g., when you only need to dump the debuggee's core.
678 * GDB now uses the GNU MPFR library, if available, to emulate target
679 floating-point arithmetic during expression evaluation when the target
680 uses different floating-point formats than the host. At least version
681 3.1 of GNU MPFR is required.
683 * GDB now supports access to the guarded-storage-control registers and the
684 software-based guarded-storage broadcast control registers on IBM z14.
686 * On Unix systems, GDB now supports transmitting environment variables
687 that are to be set or unset to GDBserver. These variables will
688 affect the environment to be passed to the remote inferior.
690 To inform GDB of environment variables that are to be transmitted to
691 GDBserver, use the "set environment" command. Only user set
692 environment variables are sent to GDBserver.
694 To inform GDB of environment variables that are to be unset before
695 the remote inferior is started by the GDBserver, use the "unset
696 environment" command.
698 * Completion improvements
700 ** GDB can now complete function parameters in linespecs and
701 explicit locations without quoting. When setting breakpoints,
702 quoting around functions names to help with TAB-completion is
703 generally no longer necessary. For example, this now completes
706 (gdb) b function(in[TAB]
707 (gdb) b function(int)
709 Related, GDB is no longer confused with completing functions in
710 C++ anonymous namespaces:
713 (gdb) b (anonymous namespace)::[TAB][TAB]
714 (anonymous namespace)::a_function()
715 (anonymous namespace)::b_function()
717 ** GDB now has much improved linespec and explicit locations TAB
718 completion support, that better understands what you're
719 completing and offers better suggestions. For example, GDB no
720 longer offers data symbols as possible completions when you're
721 setting a breakpoint.
723 ** GDB now TAB-completes label symbol names.
725 ** The "complete" command now mimics TAB completion accurately.
727 * New command line options (gcore)
730 Dump all memory mappings.
732 * Breakpoints on C++ functions are now set on all scopes by default
734 By default, breakpoints on functions/methods are now interpreted as
735 specifying all functions with the given name ignoring missing
736 leading scopes (namespaces and classes).
738 For example, assuming a C++ program with symbols named:
743 both commands "break func()" and "break B::func()" set a breakpoint
746 You can use the new flag "-qualified" to override this. This makes
747 GDB interpret the specified function name as a complete
748 fully-qualified name instead. For example, using the same C++
749 program, the "break -q B::func" command sets a breakpoint on
750 "B::func", only. A parameter has been added to the Python
751 gdb.Breakpoint constructor to achieve the same result when creating
752 a breakpoint from Python.
754 * Breakpoints on functions marked with C++ ABI tags
756 GDB can now set breakpoints on functions marked with C++ ABI tags
757 (e.g., [abi:cxx11]). See here for a description of ABI tags:
758 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
760 Functions with a C++11 abi tag are demangled/displayed like this:
762 function[abi:cxx11](int)
765 You can now set a breakpoint on such functions simply as if they had
768 (gdb) b function(int)
770 Or if you need to disambiguate between tags, like:
772 (gdb) b function[abi:other_tag](int)
774 Tab completion was adjusted accordingly as well.
778 ** New events gdb.new_inferior, gdb.inferior_deleted, and
779 gdb.new_thread are emitted. See the manual for further
780 description of these.
782 ** A new function, "gdb.rbreak" has been added to the Python API.
783 This function allows the setting of a large number of breakpoints
784 via a regex pattern in Python. See the manual for further details.
786 ** Python breakpoints can now accept explicit locations. See the
787 manual for a further description of this feature.
790 * New features in the GDB remote stub, GDBserver
792 ** GDBserver is now able to start inferior processes with a
793 specified initial working directory.
795 The user can set the desired working directory to be used from
796 GDB using the new "set cwd" command.
798 ** New "--selftest" command line option runs some GDBserver self
799 tests. These self tests are disabled in releases.
801 ** On Unix systems, GDBserver now does globbing expansion and variable
802 substitution in inferior command line arguments.
804 This is done by starting inferiors using a shell, like GDB does.
805 See "set startup-with-shell" in the user manual for how to disable
806 this from GDB when using "target extended-remote". When using
807 "target remote", you can disable the startup with shell by using the
808 new "--no-startup-with-shell" GDBserver command line option.
810 ** On Unix systems, GDBserver now supports receiving environment
811 variables that are to be set or unset from GDB. These variables
812 will affect the environment to be passed to the inferior.
814 * When catching an Ada exception raised with a message, GDB now prints
815 the message in the catchpoint hit notification. In GDB/MI mode, that
816 information is provided as an extra field named "exception-message"
817 in the *stopped notification.
819 * Trait objects can now be inspected When debugging Rust code. This
820 requires compiler support which will appear in Rust 1.24.
824 QEnvironmentHexEncoded
825 Inform GDBserver of an environment variable that is to be passed to
826 the inferior when starting it.
829 Inform GDBserver of an environment variable that is to be unset
830 before starting the remote inferior.
833 Inform GDBserver that the environment should be reset (i.e.,
834 user-set environment variables should be unset).
837 Indicates whether the inferior must be started with a shell or not.
840 Tell GDBserver that the inferior to be started should use a specific
843 * The "maintenance print c-tdesc" command now takes an optional
844 argument which is the file name of XML target description.
846 * The "maintenance selftest" command now takes an optional argument to
847 filter the tests to be run.
849 * The "enable", and "disable" commands now accept a range of
850 breakpoint locations, e.g. "enable 1.3-5".
855 Set and show the current working directory for the inferior.
858 Set and show compilation command used for compiling and injecting code
859 with the 'compile' commands.
861 set debug separate-debug-file
862 show debug separate-debug-file
863 Control the display of debug output about separate debug file search.
865 set dump-excluded-mappings
866 show dump-excluded-mappings
867 Control whether mappings marked with the VM_DONTDUMP flag should be
868 dumped when generating a core file.
871 List the registered selftests.
874 Start the debugged program stopping at the first instruction.
877 Control display of debugging messages related to OpenRISC targets.
879 set|show print type nested-type-limit
880 Set and show the limit of nesting level for nested types that the
881 type printer will show.
883 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
886 * Safer/improved support for debugging with no debug info
888 GDB no longer assumes functions with no debug information return
891 This means that GDB now refuses to call such functions unless you
892 tell it the function's type, by either casting the call to the
893 declared return type, or by casting the function to a function
894 pointer of the right type, and calling that:
896 (gdb) p getenv ("PATH")
897 'getenv' has unknown return type; cast the call to its declared return type
898 (gdb) p (char *) getenv ("PATH")
899 $1 = 0x7fffffffe "/usr/local/bin:/"...
900 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
901 $2 = 0x7fffffffe "/usr/local/bin:/"...
903 Similarly, GDB no longer assumes that global variables with no debug
904 info have type 'int', and refuses to print the variable's value
905 unless you tell it the variable's type:
908 'var' has unknown type; cast it to its declared type
912 * New native configurations
914 FreeBSD/aarch64 aarch64*-*-freebsd*
915 FreeBSD/arm arm*-*-freebsd*
919 FreeBSD/aarch64 aarch64*-*-freebsd*
920 FreeBSD/arm arm*-*-freebsd*
921 OpenRISC ELF or1k*-*-elf
923 * Removed targets and native configurations
925 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
927 *** Changes in GDB 8.0
929 * GDB now supports access to the PKU register on GNU/Linux. The register is
930 added by the Memory Protection Keys for Userspace feature which will be
931 available in future Intel CPUs.
933 * GDB now supports C++11 rvalue references.
937 ** New functions to start, stop and access a running btrace recording.
938 ** Rvalue references are now supported in gdb.Type.
940 * GDB now supports recording and replaying rdrand and rdseed Intel 64
943 * Building GDB and GDBserver now requires a C++11 compiler.
945 For example, GCC 4.8 or later.
947 It is no longer possible to build GDB or GDBserver with a C
948 compiler. The --disable-build-with-cxx configure option has been
951 * Building GDB and GDBserver now requires GNU make >= 3.81.
953 It is no longer supported to build GDB or GDBserver with another
954 implementation of the make program or an earlier version of GNU make.
956 * Native debugging on MS-Windows supports command-line redirection
958 Command-line arguments used for starting programs on MS-Windows can
959 now include redirection symbols supported by native Windows shells,
960 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
961 as "run", "start", and "set args", as well as the corresponding MI
964 * Support for thread names on MS-Windows.
966 GDB now catches and handles the special exception that programs
967 running on MS-Windows use to assign names to threads in the
970 * Support for Java programs compiled with gcj has been removed.
972 * User commands now accept an unlimited number of arguments.
973 Previously, only up to 10 was accepted.
975 * The "eval" command now expands user-defined command arguments.
977 This makes it easier to process a variable number of arguments:
982 eval "print $arg%d", $i
987 * Target descriptions can now describe registers for sparc32 and sparc64.
989 * GDB now supports DWARF version 5 (debug information format).
990 Its .debug_names index is not yet supported.
992 * New native configurations
994 FreeBSD/mips mips*-*-freebsd
998 Synopsys ARC arc*-*-elf32
999 FreeBSD/mips mips*-*-freebsd
1001 * Removed targets and native configurations
1003 Alpha running FreeBSD alpha*-*-freebsd*
1004 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1009 Erases all the flash memory regions reported by the target.
1011 maint print arc arc-instruction address
1012 Print internal disassembler information about instruction at a given address.
1016 set disassembler-options
1017 show disassembler-options
1018 Controls the passing of target specific information to the disassembler.
1019 If it is necessary to specify more than one disassembler option then
1020 multiple options can be placed together into a comma separated list.
1021 The default value is the empty string. Currently, the only supported
1022 targets are ARM, PowerPC and S/390.
1027 Erases all the flash memory regions reported by the target. This is
1028 equivalent to the CLI command flash-erase.
1030 -file-list-shared-libraries
1031 List the shared libraries in the program. This is
1032 equivalent to the CLI command "info shared".
1035 Catchpoints stopping the program when Ada exceptions are
1036 handled. This is equivalent to the CLI command "catch handlers".
1038 *** Changes in GDB 7.12
1040 * GDB and GDBserver now build with a C++ compiler by default.
1042 The --enable-build-with-cxx configure option is now enabled by
1043 default. One must now explicitly configure with
1044 --disable-build-with-cxx in order to build with a C compiler. This
1045 option will be removed in a future release.
1047 * GDBserver now supports recording btrace without maintaining an active
1050 * GDB now supports a negative repeat count in the 'x' command to examine
1051 memory backward from the given address. For example:
1054 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1055 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1056 (gdb) x/-5i 0x0000000000400580
1057 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1058 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1059 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1060 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1061 0x40057b <main(int, char**)+25>:
1062 callq 0x400536 <Func1(int, char const*)>
1064 * Fortran: Support structures with fields of dynamic types and
1065 arrays of dynamic types.
1067 * The symbol dumping maintenance commands have new syntax.
1068 maint print symbols [-pc address] [--] [filename]
1069 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1070 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1071 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1072 maint print msymbols [-objfile objfile] [--] [filename]
1074 * GDB now supports multibit bitfields and enums in target register
1077 * New Python-based convenience function $_as_string(val), which returns
1078 the textual representation of a value. This function is especially
1079 useful to obtain the text label of an enum value.
1081 * Intel MPX bound violation handling.
1083 Segmentation faults caused by a Intel MPX boundary violation
1084 now display the kind of violation (upper or lower), the memory
1085 address accessed and the memory bounds, along with the usual
1086 signal received and code location.
1090 Program received signal SIGSEGV, Segmentation fault
1091 Upper bound violation while accessing address 0x7fffffffc3b3
1092 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1093 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1095 * Rust language support.
1096 GDB now supports debugging programs written in the Rust programming
1097 language. See https://www.rust-lang.org/ for more information about
1100 * Support for running interpreters on specified input/output devices
1102 GDB now supports a new mechanism that allows frontends to provide
1103 fully featured GDB console views, as a better alternative to
1104 building such views on top of the "-interpreter-exec console"
1105 command. See the new "new-ui" command below. With that command,
1106 frontends can now start GDB in the traditional command-line mode
1107 running in an embedded terminal emulator widget, and create a
1108 separate MI interpreter running on a specified i/o device. In this
1109 way, GDB handles line editing, history, tab completion, etc. in the
1110 console all by itself, and the GUI uses the separate MI interpreter
1111 for its own control and synchronization, invisible to the command
1114 * The "catch syscall" command catches groups of related syscalls.
1116 The "catch syscall" command now supports catching a group of related
1117 syscalls using the 'group:' or 'g:' prefix.
1122 skip -gfile file-glob-pattern
1123 skip -function function
1124 skip -rfunction regular-expression
1125 A generalized form of the skip command, with new support for
1126 glob-style file names and regular expressions for function names.
1127 Additionally, a file spec and a function spec may now be combined.
1129 maint info line-table REGEXP
1130 Display the contents of GDB's internal line table data struture.
1133 Run any GDB unit tests that were compiled in.
1136 Start a new user interface instance running INTERP as interpreter,
1137 using the TTY file for input/output.
1141 ** gdb.Breakpoint objects have a new attribute "pending", which
1142 indicates whether the breakpoint is pending.
1143 ** Three new breakpoint-related events have been added:
1144 gdb.breakpoint_created, gdb.breakpoint_modified, and
1145 gdb.breakpoint_deleted.
1147 signal-event EVENTID
1148 Signal ("set") the given MS-Windows event object. This is used in
1149 conjunction with the Windows JIT debugging (AeDebug) support, where
1150 the OS suspends a crashing process until a debugger can attach to
1151 it. Resuming the crashing process, in order to debug it, is done by
1152 signalling an event.
1154 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1155 was added in GDBserver, including JIT compiling fast tracepoint's
1156 conditional expression bytecode into native code.
1158 * Support for various remote target protocols and ROM monitors has
1161 target m32rsdi Remote M32R debugging over SDI
1162 target mips MIPS remote debugging protocol
1163 target pmon PMON ROM monitor
1164 target ddb NEC's DDB variant of PMON for Vr4300
1165 target rockhopper NEC RockHopper variant of PMON
1166 target lsi LSI variant of PMO
1168 * Support for tracepoints and fast tracepoints on powerpc-linux,
1169 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1170 including JIT compiling fast tracepoint's conditional expression
1171 bytecode into native code.
1173 * MI async record =record-started now includes the method and format used for
1174 recording. For example:
1176 =record-started,thread-group="i1",method="btrace",format="bts"
1178 * MI async record =thread-selected now includes the frame field. For example:
1180 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1184 Andes NDS32 nds32*-*-elf
1186 *** Changes in GDB 7.11
1188 * GDB now supports debugging kernel-based threads on FreeBSD.
1190 * Per-inferior thread numbers
1192 Thread numbers are now per inferior instead of global. If you're
1193 debugging multiple inferiors, GDB displays thread IDs using a
1194 qualified INF_NUM.THR_NUM form. For example:
1198 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1199 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1200 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1201 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1203 As consequence, thread numbers as visible in the $_thread
1204 convenience variable and in Python's InferiorThread.num attribute
1205 are no longer unique between inferiors.
1207 GDB now maintains a second thread ID per thread, referred to as the
1208 global thread ID, which is the new equivalent of thread numbers in
1209 previous releases. See also $_gthread below.
1211 For backwards compatibility, MI's thread IDs always refer to global
1214 * Commands that accept thread IDs now accept the qualified
1215 INF_NUM.THR_NUM form as well. For example:
1218 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1221 * In commands that accept a list of thread IDs, you can now refer to
1222 all threads of an inferior using a star wildcard. GDB accepts
1223 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1224 refer to all threads of the current inferior. For example, "info
1227 * You can use "info threads -gid" to display the global thread ID of
1230 * The new convenience variable $_gthread holds the global number of
1233 * The new convenience variable $_inferior holds the number of the
1236 * GDB now displays the ID and name of the thread that hit a breakpoint
1237 or received a signal, if your program is multi-threaded. For
1240 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1241 Thread 1 "main" received signal SIGINT, Interrupt.
1243 * Record btrace now supports non-stop mode.
1245 * Support for tracepoints on aarch64-linux was added in GDBserver.
1247 * The 'record instruction-history' command now indicates speculative execution
1248 when using the Intel Processor Trace recording format.
1250 * GDB now allows users to specify explicit locations, bypassing
1251 the linespec parser. This feature is also available to GDB/MI
1254 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1255 GDB now is able to debug both AArch64 applications and ARM applications
1258 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1259 including JIT compiling fast tracepoint's conditional expression bytecode
1262 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1264 * "info threads", "info inferiors", "info display", "info checkpoints"
1265 and "maint info program-spaces" now list the corresponding items in
1266 ascending ID order, for consistency with all other "info" commands.
1268 * In Ada, the overloads selection menu has been enhanced to display the
1269 parameter types and the return types for the matching overloaded subprograms.
1273 maint set target-non-stop (on|off|auto)
1274 maint show target-non-stop
1275 Control whether GDB targets always operate in non-stop mode even if
1276 "set non-stop" is "off". The default is "auto", meaning non-stop
1277 mode is enabled if supported by the target.
1279 maint set bfd-sharing
1280 maint show bfd-sharing
1281 Control the reuse of bfd objects.
1284 show debug bfd-cache
1285 Control display of debugging info regarding bfd caching.
1289 Control display of debugging info regarding FreeBSD threads.
1291 set remote multiprocess-extensions-packet
1292 show remote multiprocess-extensions-packet
1293 Set/show the use of the remote protocol multiprocess extensions.
1295 set remote thread-events
1296 show remote thread-events
1297 Set/show the use of thread create/exit events.
1299 set ada print-signatures on|off
1300 show ada print-signatures"
1301 Control whether parameter types and return types are displayed in overloads
1302 selection menus. It is activaled (@code{on}) by default.
1306 Controls the maximum size of memory, in bytes, that GDB will
1307 allocate for value contents. Prevents incorrect programs from
1308 causing GDB to allocate overly large buffers. Default is 64k.
1310 * The "disassemble" command accepts a new modifier: /s.
1311 It prints mixed source+disassembly like /m with two differences:
1312 - disassembled instructions are now printed in program order, and
1313 - and source for all relevant files is now printed.
1314 The "/m" option is now considered deprecated: its "source-centric"
1315 output hasn't proved useful in practice.
1317 * The "record instruction-history" command accepts a new modifier: /s.
1318 It behaves exactly like /m and prints mixed source+disassembly.
1320 * The "set scheduler-locking" command supports a new mode "replay".
1321 It behaves like "off" in record mode and like "on" in replay mode.
1323 * Support for various ROM monitors has been removed:
1325 target dbug dBUG ROM monitor for Motorola ColdFire
1326 target picobug Motorola picobug monitor
1327 target dink32 DINK32 ROM monitor for PowerPC
1328 target m32r Renesas M32R/D ROM monitor
1329 target mon2000 mon2000 ROM monitor
1330 target ppcbug PPCBUG ROM monitor for PowerPC
1332 * Support for reading/writing memory and extracting values on architectures
1333 whose memory is addressable in units of any integral multiple of 8 bits.
1336 Allows to break when an Ada exception is handled.
1338 * New remote packets
1341 Indicates that an exec system call was executed.
1343 exec-events feature in qSupported
1344 The qSupported packet allows GDB to request support for exec
1345 events using the new 'gdbfeature' exec-event, and the qSupported
1346 response can contain the corresponding 'stubfeature'. Set and
1347 show commands can be used to display whether these features are enabled.
1350 Equivalent to interrupting with the ^C character, but works in
1353 thread created stop reason (T05 create:...)
1354 Indicates that the thread was just created and is stopped at entry.
1356 thread exit stop reply (w exitcode;tid)
1357 Indicates that the thread has terminated.
1360 Enables/disables thread create and exit event reporting. For
1361 example, this is used in non-stop mode when GDB stops a set of
1362 threads and synchronously waits for the their corresponding stop
1363 replies. Without exit events, if one of the threads exits, GDB
1364 would hang forever not knowing that it should no longer expect a
1365 stop for that same thread.
1368 Indicates that there are no resumed threads left in the target (all
1369 threads are stopped). The remote stub reports support for this stop
1370 reply to GDB's qSupported query.
1373 Enables/disables catching syscalls from the inferior process.
1374 The remote stub reports support for this packet to GDB's qSupported query.
1376 syscall_entry stop reason
1377 Indicates that a syscall was just called.
1379 syscall_return stop reason
1380 Indicates that a syscall just returned.
1382 * Extended-remote exec events
1384 ** GDB now has support for exec events on extended-remote Linux targets.
1385 For such targets with Linux kernels 2.5.46 and later, this enables
1386 follow-exec-mode and exec catchpoints.
1388 set remote exec-event-feature-packet
1389 show remote exec-event-feature-packet
1390 Set/show the use of the remote exec event feature.
1392 * Thread names in remote protocol
1394 The reply to qXfer:threads:read may now include a name attribute for each
1397 * Target remote mode fork and exec events
1399 ** GDB now has support for fork and exec events on target remote mode
1400 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1401 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1402 fork and exec catchpoints.
1404 * Remote syscall events
1406 ** GDB now has support for catch syscall on remote Linux targets,
1407 currently enabled on x86/x86_64 architectures.
1409 set remote catch-syscall-packet
1410 show remote catch-syscall-packet
1411 Set/show the use of the remote catch syscall feature.
1415 ** The -var-set-format command now accepts the zero-hexadecimal
1416 format. It outputs data in hexadecimal format with zero-padding on the
1421 ** gdb.InferiorThread objects have a new attribute "global_num",
1422 which refers to the thread's global thread ID. The existing
1423 "num" attribute now refers to the thread's per-inferior number.
1424 See "Per-inferior thread numbers" above.
1425 ** gdb.InferiorThread objects have a new attribute "inferior", which
1426 is the Inferior object the thread belongs to.
1428 *** Changes in GDB 7.10
1430 * Support for process record-replay and reverse debugging on aarch64*-linux*
1431 targets has been added. GDB now supports recording of A64 instruction set
1432 including advance SIMD instructions.
1434 * Support for Sun's version of the "stabs" debug file format has been removed.
1436 * GDB now honors the content of the file /proc/PID/coredump_filter
1437 (PID is the process ID) on GNU/Linux systems. This file can be used
1438 to specify the types of memory mappings that will be included in a
1439 corefile. For more information, please refer to the manual page of
1440 "core(5)". GDB also has a new command: "set use-coredump-filter
1441 on|off". It allows to set whether GDB will read the content of the
1442 /proc/PID/coredump_filter file when generating a corefile.
1444 * The "info os" command on GNU/Linux can now display information on
1446 "info os cpus" Listing of all cpus/cores on the system
1448 * GDB has two new commands: "set serial parity odd|even|none" and
1449 "show serial parity". These allows to set or show parity for the
1452 * The "info source" command now displays the producer string if it was
1453 present in the debug info. This typically includes the compiler version
1454 and may include things like its command line arguments.
1456 * The "info dll", an alias of the "info sharedlibrary" command,
1457 is now available on all platforms.
1459 * Directory names supplied to the "set sysroot" commands may be
1460 prefixed with "target:" to tell GDB to access shared libraries from
1461 the target system, be it local or remote. This replaces the prefix
1462 "remote:". The default sysroot has been changed from "" to
1463 "target:". "remote:" is automatically converted to "target:" for
1464 backward compatibility.
1466 * The system root specified by "set sysroot" will be prepended to the
1467 filename of the main executable (if reported to GDB as absolute by
1468 the operating system) when starting processes remotely, and when
1469 attaching to already-running local or remote processes.
1471 * GDB now supports automatic location and retrieval of executable
1472 files from remote targets. Remote debugging can now be initiated
1473 using only a "target remote" or "target extended-remote" command
1474 (no "set sysroot" or "file" commands are required). See "New remote
1477 * The "dump" command now supports verilog hex format.
1479 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1481 * On GNU/Linux, GDB and gdbserver are now able to access executable
1482 and shared library files without a "set sysroot" command when
1483 attaching to processes running in different mount namespaces from
1484 the debugger. This makes it possible to attach to processes in
1485 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1486 See "New remote packets" below.
1488 * The "tui reg" command now provides completion for all of the
1489 available register groups, including target specific groups.
1491 * The HISTSIZE environment variable is no longer read when determining
1492 the size of GDB's command history. GDB now instead reads the dedicated
1493 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1494 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1499 ** Memory ports can now be unbuffered.
1503 ** gdb.Objfile objects have a new attribute "username",
1504 which is the name of the objfile as specified by the user,
1505 without, for example, resolving symlinks.
1506 ** You can now write frame unwinders in Python.
1507 ** gdb.Type objects have a new method "optimized_out",
1508 returning optimized out gdb.Value instance of this type.
1509 ** gdb.Value objects have new methods "reference_value" and
1510 "const_value" which return a reference to the value and a
1511 "const" version of the value respectively.
1515 maint print symbol-cache
1516 Print the contents of the symbol cache.
1518 maint print symbol-cache-statistics
1519 Print statistics of symbol cache usage.
1521 maint flush-symbol-cache
1522 Flush the contents of the symbol cache.
1526 Start branch trace recording using Branch Trace Store (BTS) format.
1529 Evaluate expression by using the compiler and print result.
1533 Explicit commands for enabling and disabling tui mode.
1536 set mpx bound on i386 and amd64
1537 Support for bound table investigation on Intel MPX enabled applications.
1541 Start branch trace recording using Intel Processor Trace format.
1544 Print information about branch tracing internals.
1546 maint btrace packet-history
1547 Print the raw branch tracing data.
1549 maint btrace clear-packet-history
1550 Discard the stored raw branch tracing data.
1553 Discard all branch tracing data. It will be fetched and processed
1554 anew by the next "record" command.
1559 Renamed from "set debug dwarf2-die".
1560 show debug dwarf-die
1561 Renamed from "show debug dwarf2-die".
1563 set debug dwarf-read
1564 Renamed from "set debug dwarf2-read".
1565 show debug dwarf-read
1566 Renamed from "show debug dwarf2-read".
1568 maint set dwarf always-disassemble
1569 Renamed from "maint set dwarf2 always-disassemble".
1570 maint show dwarf always-disassemble
1571 Renamed from "maint show dwarf2 always-disassemble".
1573 maint set dwarf max-cache-age
1574 Renamed from "maint set dwarf2 max-cache-age".
1575 maint show dwarf max-cache-age
1576 Renamed from "maint show dwarf2 max-cache-age".
1578 set debug dwarf-line
1579 show debug dwarf-line
1580 Control display of debugging info regarding DWARF line processing.
1583 show max-completions
1584 Set the maximum number of candidates to be considered during
1585 completion. The default value is 200. This limit allows GDB
1586 to avoid generating large completion lists, the computation of
1587 which can cause the debugger to become temporarily unresponsive.
1589 set history remove-duplicates
1590 show history remove-duplicates
1591 Control the removal of duplicate history entries.
1593 maint set symbol-cache-size
1594 maint show symbol-cache-size
1595 Control the size of the symbol cache.
1597 set|show record btrace bts buffer-size
1598 Set and show the size of the ring buffer used for branch tracing in
1600 The obtained size may differ from the requested size. Use "info
1601 record" to see the obtained buffer size.
1603 set debug linux-namespaces
1604 show debug linux-namespaces
1605 Control display of debugging info regarding Linux namespaces.
1607 set|show record btrace pt buffer-size
1608 Set and show the size of the ring buffer used for branch tracing in
1609 Intel Processor Trace format.
1610 The obtained size may differ from the requested size. Use "info
1611 record" to see the obtained buffer size.
1613 maint set|show btrace pt skip-pad
1614 Set and show whether PAD packets are skipped when computing the
1617 * The command 'thread apply all' can now support new option '-ascending'
1618 to call its specified command for all threads in ascending order.
1620 * Python/Guile scripting
1622 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1623 special section named `.debug_gdb_scripts'.
1625 * New remote packets
1627 qXfer:btrace-conf:read
1628 Return the branch trace configuration for the current thread.
1630 Qbtrace-conf:bts:size
1631 Set the requested ring buffer size for branch tracing in BTS format.
1634 Enable Intel Procesor Trace-based branch tracing for the current
1635 process. The remote stub reports support for this packet to GDB's
1638 Qbtrace-conf:pt:size
1639 Set the requested ring buffer size for branch tracing in Intel Processor
1643 Indicates a memory breakpoint instruction was executed, irrespective
1644 of whether it was GDB that planted the breakpoint or the breakpoint
1645 is hardcoded in the program. This is required for correct non-stop
1649 Indicates the target stopped for a hardware breakpoint. This is
1650 required for correct non-stop mode operation.
1653 Return information about files on the remote system.
1655 qXfer:exec-file:read
1656 Return the full absolute name of the file that was executed to
1657 create a process running on the remote system.
1660 Select the filesystem on which vFile: operations with filename
1661 arguments will operate. This is required for GDB to be able to
1662 access files on remote targets where the remote stub does not
1663 share a common filesystem with the inferior(s).
1666 Indicates that a fork system call was executed.
1669 Indicates that a vfork system call was executed.
1671 vforkdone stop reason
1672 Indicates that a vfork child of the specified process has executed
1673 an exec or exit, allowing the vfork parent to resume execution.
1675 fork-events and vfork-events features in qSupported
1676 The qSupported packet allows GDB to request support for fork and
1677 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1678 and the qSupported response can contain the corresponding
1679 'stubfeatures'. Set and show commands can be used to display
1680 whether these features are enabled.
1682 * Extended-remote fork events
1684 ** GDB now has support for fork events on extended-remote Linux
1685 targets. For targets with Linux kernels 2.5.60 and later, this
1686 enables follow-fork-mode and detach-on-fork for both fork and
1687 vfork, as well as fork and vfork catchpoints.
1689 * The info record command now shows the recording format and the
1690 branch tracing configuration for the current thread when using
1691 the btrace record target.
1692 For the BTS format, it shows the ring buffer size.
1694 * GDB now has support for DTrace USDT (Userland Static Defined
1695 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1697 * GDB now supports access to vector registers on S/390 GNU/Linux
1700 * Removed command line options
1702 -xdb HP-UX XDB compatibility mode.
1704 * Removed targets and native configurations
1706 HP/PA running HP-UX hppa*-*-hpux*
1707 Itanium running HP-UX ia64-*-hpux*
1709 * New configure options
1712 This configure option allows the user to build GDB with support for
1713 Intel Processor Trace (default: auto). This requires libipt.
1715 --with-libipt-prefix=PATH
1716 Specify the path to the version of libipt that GDB should use.
1717 $PATH/include should contain the intel-pt.h header and
1718 $PATH/lib should contain the libipt.so library.
1720 *** Changes in GDB 7.9.1
1724 ** Xmethods can now specify a result type.
1726 *** Changes in GDB 7.9
1728 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1732 ** You can now access frame registers from Python scripts.
1733 ** New attribute 'producer' for gdb.Symtab objects.
1734 ** gdb.Objfile objects have a new attribute "progspace",
1735 which is the gdb.Progspace object of the containing program space.
1736 ** gdb.Objfile objects have a new attribute "owner".
1737 ** gdb.Objfile objects have a new attribute "build_id",
1738 which is the build ID generated when the file was built.
1739 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1740 ** A new event "gdb.clear_objfiles" has been added, triggered when
1741 selecting a new file to debug.
1742 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1743 ** New function gdb.lookup_objfile.
1745 New events which are triggered when GDB modifies the state of the
1748 ** gdb.events.inferior_call_pre: Function call is about to be made.
1749 ** gdb.events.inferior_call_post: Function call has just been made.
1750 ** gdb.events.memory_changed: A memory location has been altered.
1751 ** gdb.events.register_changed: A register has been altered.
1753 * New Python-based convenience functions:
1755 ** $_caller_is(name [, number_of_frames])
1756 ** $_caller_matches(regexp [, number_of_frames])
1757 ** $_any_caller_is(name [, number_of_frames])
1758 ** $_any_caller_matches(regexp [, number_of_frames])
1760 * GDB now supports the compilation and injection of source code into
1761 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1762 to compile the source code to object code, and if successful, inject
1763 and execute that code within the current context of the inferior.
1764 Currently the C language is supported. The commands used to
1765 interface with this new feature are:
1767 compile code [-raw|-r] [--] [source code]
1768 compile file [-raw|-r] filename
1772 demangle [-l language] [--] name
1773 Demangle "name" in the specified language, or the current language
1774 if elided. This command is renamed from the "maint demangle" command.
1775 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1776 as "maint demangler-warning".
1778 queue-signal signal-name-or-number
1779 Queue a signal to be delivered to the thread when it is resumed.
1781 add-auto-load-scripts-directory directory
1782 Add entries to the list of directories from which to load auto-loaded
1785 maint print user-registers
1786 List all currently available "user" registers.
1788 compile code [-r|-raw] [--] [source code]
1789 Compile, inject, and execute in the inferior the executable object
1790 code produced by compiling the provided source code.
1792 compile file [-r|-raw] filename
1793 Compile and inject into the inferior the executable object code
1794 produced by compiling the source code stored in the filename
1797 * On resume, GDB now always passes the signal the program had stopped
1798 for to the thread the signal was sent to, even if the user changed
1799 threads before resuming. Previously GDB would often (but not
1800 always) deliver the signal to the thread that happens to be current
1803 * Conversely, the "signal" command now consistently delivers the
1804 requested signal to the current thread. GDB now asks for
1805 confirmation if the program had stopped for a signal and the user
1806 switched threads meanwhile.
1808 * "breakpoint always-inserted" modes "off" and "auto" merged.
1810 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1811 won't remove breakpoints from the target until all threads stop,
1812 even in non-stop mode. The "auto" mode has been removed, and "off"
1813 is now the default mode.
1817 set debug symbol-lookup
1818 show debug symbol-lookup
1819 Control display of debugging info regarding symbol lookup.
1823 ** The -list-thread-groups command outputs an exit-code field for
1824 inferiors that have exited.
1828 MIPS SDE mips*-sde*-elf*
1832 Support for these obsolete configurations has been removed.
1834 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1835 SGI Irix-5.x mips-*-irix5*
1836 SGI Irix-6.x mips-*-irix6*
1837 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1838 VAX running Ultrix vax-*-ultrix*
1840 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1841 and "assf"), have been removed. Use the "sharedlibrary" command, or
1842 its alias "share", instead.
1844 *** Changes in GDB 7.8
1846 * New command line options
1849 This is an alias for the --data-directory option.
1851 * GDB supports printing and modifying of variable length automatic arrays
1852 as specified in ISO C99.
1854 * The ARM simulator now supports instruction level tracing
1855 with or without disassembly.
1859 GDB now has support for scripting using Guile. Whether this is
1860 available is determined at configure time.
1861 Guile version 2.0 or greater is required.
1862 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1864 * New commands (for set/show, see "New options" below)
1868 Invoke CODE by passing it to the Guile interpreter.
1872 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1874 info auto-load guile-scripts [regexp]
1875 Print the list of automatically loaded Guile scripts.
1877 * The source command is now capable of sourcing Guile scripts.
1878 This feature is dependent on the debugger being built with Guile support.
1882 set print symbol-loading (off|brief|full)
1883 show print symbol-loading
1884 Control whether to print informational messages when loading symbol
1885 information for a file. The default is "full", but when debugging
1886 programs with large numbers of shared libraries the amount of output
1887 becomes less useful.
1889 set guile print-stack (none|message|full)
1890 show guile print-stack
1891 Show a stack trace when an error is encountered in a Guile script.
1893 set auto-load guile-scripts (on|off)
1894 show auto-load guile-scripts
1895 Control auto-loading of Guile script files.
1897 maint ada set ignore-descriptive-types (on|off)
1898 maint ada show ignore-descriptive-types
1899 Control whether the debugger should ignore descriptive types in Ada
1900 programs. The default is not to ignore the descriptive types. See
1901 the user manual for more details on descriptive types and the intended
1902 usage of this option.
1904 set auto-connect-native-target
1906 Control whether GDB is allowed to automatically connect to the
1907 native target for the run, attach, etc. commands when not connected
1908 to any target yet. See also "target native" below.
1910 set record btrace replay-memory-access (read-only|read-write)
1911 show record btrace replay-memory-access
1912 Control what memory accesses are allowed during replay.
1914 maint set target-async (on|off)
1915 maint show target-async
1916 This controls whether GDB targets operate in synchronous or
1917 asynchronous mode. Normally the default is asynchronous, if it is
1918 available; but this can be changed to more easily debug problems
1919 occurring only in synchronous mode.
1921 set mi-async (on|off)
1923 Control whether MI asynchronous mode is preferred. This supersedes
1924 "set target-async" of previous GDB versions.
1926 * "set target-async" is deprecated as a CLI option and is now an alias
1927 for "set mi-async" (only puts MI into async mode).
1929 * Background execution commands (e.g., "c&", "s&", etc.) are now
1930 possible ``out of the box'' if the target supports them. Previously
1931 the user would need to explicitly enable the possibility with the
1932 "set target-async on" command.
1934 * New features in the GDB remote stub, GDBserver
1936 ** New option --debug-format=option1[,option2,...] allows one to add
1937 additional text to each output. At present only timestamps
1938 are supported: --debug-format=timestamps.
1939 Timestamps can also be turned on with the
1940 "monitor set debug-format timestamps" command from GDB.
1942 * The 'record instruction-history' command now starts counting instructions
1943 at one. This also affects the instruction ranges reported by the
1944 'record function-call-history' command when given the /i modifier.
1946 * The command 'record function-call-history' supports a new modifier '/c' to
1947 indent the function names based on their call stack depth.
1948 The fields for the '/i' and '/l' modifier have been reordered.
1949 The source line range is now prefixed with 'at'.
1950 The instruction range is now prefixed with 'inst'.
1951 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1952 "record instruction-history" and "list" commands.
1954 * The ranges given as arguments to the 'record function-call-history' and
1955 'record instruction-history' commands are now inclusive.
1957 * The btrace record target now supports the 'record goto' command.
1958 For locations inside the execution trace, the back trace is computed
1959 based on the information stored in the execution trace.
1961 * The btrace record target supports limited reverse execution and replay.
1962 The target does not record data and therefore does not allow reading
1963 memory or registers.
1965 * The "catch syscall" command now works on s390*-linux* targets.
1967 * The "compare-sections" command is no longer specific to target
1968 remote. It now works with all targets.
1970 * All native targets are now consistently called "native".
1971 Consequently, the "target child", "target GNU", "target djgpp",
1972 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1973 commands have been replaced with "target native". The QNX/NTO port
1974 leaves the "procfs" target in place and adds a "native" target for
1975 consistency with other ports. The impact on users should be minimal
1976 as these commands previously either throwed an error, or were
1977 no-ops. The target's name is visible in the output of the following
1978 commands: "help target", "info target", "info files", "maint print
1981 * The "target native" command now connects to the native target. This
1982 can be used to launch native programs even when "set
1983 auto-connect-native-target" is set to off.
1985 * GDB now supports access to Intel MPX registers on GNU/Linux.
1987 * Support for Intel AVX-512 registers on GNU/Linux.
1988 Support displaying and modifying Intel AVX-512 registers
1989 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1991 * New remote packets
1993 qXfer:btrace:read's annex
1994 The qXfer:btrace:read packet supports a new annex 'delta' to read
1995 branch trace incrementally.
1999 ** Valid Python operations on gdb.Value objects representing
2000 structs/classes invoke the corresponding overloaded operators if
2002 ** New `Xmethods' feature in the Python API. Xmethods are
2003 additional methods or replacements for existing methods of a C++
2004 class. This feature is useful for those cases where a method
2005 defined in C++ source code could be inlined or optimized out by
2006 the compiler, making it unavailable to GDB.
2009 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2011 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2012 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2013 its alias "share", instead.
2015 * The commands "set remotebaud" and "show remotebaud" are no longer
2016 supported. Use "set serial baud" and "show serial baud" (respectively)
2021 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2022 target-async". The latter is left as a deprecated alias of the
2023 former for backward compatibility. If the target supports it,
2024 CLI background execution commands are now always possible by
2025 default, independently of whether the frontend stated a
2026 preference for asynchronous execution with "-gdb-set mi-async".
2027 Previously "-gdb-set target-async off" affected both MI execution
2028 commands and CLI execution commands.
2030 *** Changes in GDB 7.7
2032 * Improved support for process record-replay and reverse debugging on
2033 arm*-linux* targets. Support for thumb32 and syscall instruction
2034 recording has been added.
2036 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2038 * GDB now supports Fission DWP file format version 2.
2039 http://gcc.gnu.org/wiki/DebugFission
2041 * New convenience function "$_isvoid", to check whether an expression
2042 is void. A void expression is an expression where the type of the
2043 result is "void". For example, some convenience variables may be
2044 "void" when evaluated (e.g., "$_exitcode" before the execution of
2045 the program being debugged; or an undefined convenience variable).
2046 Another example, when calling a function whose return type is
2049 * The "maintenance print objfiles" command now takes an optional regexp.
2051 * The "catch syscall" command now works on arm*-linux* targets.
2053 * GDB now consistently shows "<not saved>" when printing values of
2054 registers the debug info indicates have not been saved in the frame
2055 and there's nowhere to retrieve them from
2056 (callee-saved/call-clobbered registers):
2061 (gdb) info registers rax
2064 Before, the former would print "<optimized out>", and the latter
2065 "*value not available*".
2067 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2072 ** Frame filters and frame decorators have been added.
2073 ** Temporary breakpoints are now supported.
2074 ** Line tables representation has been added.
2075 ** New attribute 'parent_type' for gdb.Field objects.
2076 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2077 ** New attribute 'name' for gdb.Type objects.
2081 Nios II ELF nios2*-*-elf
2082 Nios II GNU/Linux nios2*-*-linux
2083 Texas Instruments MSP430 msp430*-*-elf
2085 * Removed native configurations
2087 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2088 been removed. ELF variants of these configurations are kept supported.
2090 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2091 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2092 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2093 i[34567]86-*-openbsd3.[0-3]
2094 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2095 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2096 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2100 Like "catch throw", but catches a re-thrown exception.
2101 maint check-psymtabs
2102 Renamed from old "maint check-symtabs".
2104 Perform consistency checks on symtabs.
2105 maint expand-symtabs
2106 Expand symtabs matching an optional regexp.
2109 Display the details of GDB configure-time options.
2111 maint set|show per-command
2112 maint set|show per-command space
2113 maint set|show per-command time
2114 maint set|show per-command symtab
2115 Enable display of per-command gdb resource usage.
2117 remove-symbol-file FILENAME
2118 remove-symbol-file -a ADDRESS
2119 Remove a symbol file added via add-symbol-file. The file to remove
2120 can be identified by its filename or by an address that lies within
2121 the boundaries of this symbol file in memory.
2124 info exceptions REGEXP
2125 Display the list of Ada exceptions defined in the program being
2126 debugged. If provided, only the exceptions whose names match REGEXP
2131 set debug symfile off|on
2133 Control display of debugging info regarding reading symbol files and
2134 symbol tables within those files
2136 set print raw frame-arguments
2137 show print raw frame-arguments
2138 Set/show whether to print frame arguments in raw mode,
2139 disregarding any defined pretty-printers.
2141 set remote trace-status-packet
2142 show remote trace-status-packet
2143 Set/show the use of remote protocol qTStatus packet.
2147 Control display of debugging messages related to Nios II targets.
2151 Control whether target-assisted range stepping is enabled.
2153 set startup-with-shell
2154 show startup-with-shell
2155 Specifies whether Unix child processes are started via a shell or
2160 Use the target memory cache for accesses to the code segment. This
2161 improves performance of remote debugging (particularly disassembly).
2163 * You can now use a literal value 'unlimited' for options that
2164 interpret 0 or -1 as meaning "unlimited". E.g., "set
2165 trace-buffer-size unlimited" is now an alias for "set
2166 trace-buffer-size -1" and "set height unlimited" is now an alias for
2169 * The "set debug symtab-create" debugging option of GDB has been changed to
2170 accept a verbosity level. 0 means "off", 1 provides basic debugging
2171 output, and values of 2 or greater provides more verbose output.
2173 * New command-line options
2175 Display the details of GDB configure-time options.
2177 * The command 'tsave' can now support new option '-ctf' to save trace
2178 buffer in Common Trace Format.
2180 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2183 * GDB now implements the the C++ 'typeid' operator.
2185 * The new convenience variable $_exception holds the exception being
2186 thrown or caught at an exception-related catchpoint.
2188 * The exception-related catchpoints, like "catch throw", now accept a
2189 regular expression which can be used to filter exceptions by type.
2191 * The new convenience variable $_exitsignal is automatically set to
2192 the terminating signal number when the program being debugged dies
2193 due to an uncaught signal.
2197 ** All MI commands now accept an optional "--language" option.
2198 Support for this feature can be verified by using the "-list-features"
2199 command, which should contain "language-option".
2201 ** The new command -info-gdb-mi-command allows the user to determine
2202 whether a GDB/MI command is supported or not.
2204 ** The "^error" result record returned when trying to execute an undefined
2205 GDB/MI command now provides a variable named "code" whose content is the
2206 "undefined-command" error code. Support for this feature can be verified
2207 by using the "-list-features" command, which should contain
2208 "undefined-command-error-code".
2210 ** The -trace-save MI command can optionally save trace buffer in Common
2213 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2215 ** The command -data-list-register-values now accepts an optional
2216 "--skip-unavailable" option. When used, only the available registers
2219 ** The new command -trace-frame-collected dumps collected variables,
2220 computed expressions, tvars, memory and registers in a traceframe.
2222 ** The commands -stack-list-locals, -stack-list-arguments and
2223 -stack-list-variables now accept an option "--skip-unavailable".
2224 When used, only the available locals or arguments are displayed.
2226 ** The -exec-run command now accepts an optional "--start" option.
2227 When used, the command follows the same semantics as the "start"
2228 command, stopping the program's execution at the start of its
2229 main subprogram. Support for this feature can be verified using
2230 the "-list-features" command, which should contain
2231 "exec-run-start-option".
2233 ** The new commands -catch-assert and -catch-exceptions insert
2234 catchpoints stopping the program when Ada exceptions are raised.
2236 ** The new command -info-ada-exceptions provides the equivalent of
2237 the new "info exceptions" command.
2239 * New system-wide configuration scripts
2240 A GDB installation now provides scripts suitable for use as system-wide
2241 configuration scripts for the following systems:
2245 * GDB now supports target-assigned range stepping with remote targets.
2246 This improves the performance of stepping source lines by reducing
2247 the number of control packets from/to GDB. See "New remote packets"
2250 * GDB now understands the element 'tvar' in the XML traceframe info.
2251 It has the id of the collected trace state variables.
2253 * On S/390 targets that provide the transactional-execution feature,
2254 the program interruption transaction diagnostic block (TDB) is now
2255 represented as a number of additional "registers" in GDB.
2257 * New remote packets
2261 The vCont packet supports a new 'r' action, that tells the remote
2262 stub to step through an address range itself, without GDB
2263 involvemement at each single-step.
2265 qXfer:libraries-svr4:read's annex
2266 The previously unused annex of the qXfer:libraries-svr4:read packet
2267 is now used to support passing an argument list. The remote stub
2268 reports support for this argument list to GDB's qSupported query.
2269 The defined arguments are "start" and "prev", used to reduce work
2270 necessary for library list updating, resulting in significant
2273 * New features in the GDB remote stub, GDBserver
2275 ** GDBserver now supports target-assisted range stepping. Currently
2276 enabled on x86/x86_64 GNU/Linux targets.
2278 ** GDBserver now adds element 'tvar' in the XML in the reply to
2279 'qXfer:traceframe-info:read'. It has the id of the collected
2280 trace state variables.
2282 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2285 * New 'z' formatter for printing and examining memory, this displays the
2286 value as hexadecimal zero padded on the left to the size of the type.
2288 * GDB can now use Windows x64 unwinding data.
2290 * The "set remotebaud" command has been replaced by "set serial baud".
2291 Similarly, "show remotebaud" has been replaced by "show serial baud".
2292 The "set remotebaud" and "show remotebaud" commands are still available
2293 to provide backward compatibility with older versions of GDB.
2295 *** Changes in GDB 7.6
2297 * Target record has been renamed to record-full.
2298 Record/replay is now enabled with the "record full" command.
2299 This also affects settings that are associated with full record/replay
2300 that have been moved from "set/show record" to "set/show record full":
2302 set|show record full insn-number-max
2303 set|show record full stop-at-limit
2304 set|show record full memory-query
2306 * A new record target "record-btrace" has been added. The new target
2307 uses hardware support to record the control-flow of a process. It
2308 does not support replaying the execution, but it implements the
2309 below new commands for investigating the recorded execution log.
2310 This new recording method can be enabled using:
2314 The "record-btrace" target is only available on Intel Atom processors
2315 and requires a Linux kernel 2.6.32 or later.
2317 * Two new commands have been added for record/replay to give information
2318 about the recorded execution without having to replay the execution.
2319 The commands are only supported by "record btrace".
2321 record instruction-history prints the execution history at
2322 instruction granularity
2324 record function-call-history prints the execution history at
2325 function granularity
2327 * New native configurations
2329 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2330 FreeBSD/powerpc powerpc*-*-freebsd
2331 x86_64/Cygwin x86_64-*-cygwin*
2332 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2336 ARM AArch64 aarch64*-*-elf
2337 ARM AArch64 GNU/Linux aarch64*-*-linux
2338 Lynx 178 PowerPC powerpc-*-lynx*178
2339 x86_64/Cygwin x86_64-*-cygwin*
2340 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2342 * If the configured location of system.gdbinit file (as given by the
2343 --with-system-gdbinit option at configure time) is in the
2344 data-directory (as specified by --with-gdb-datadir at configure
2345 time) or in one of its subdirectories, then GDB will look for the
2346 system-wide init file in the directory specified by the
2347 --data-directory command-line option.
2349 * New command line options:
2351 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2352 other initialization files, unlike -nx which disables all of them.
2354 * Removed command line options
2356 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2359 * The 'ptype' and 'whatis' commands now accept an argument to control
2362 * 'info proc' now works on some core files.
2366 ** Vectors can be created with gdb.Type.vector.
2368 ** Python's atexit.register now works in GDB.
2370 ** Types can be pretty-printed via a Python API.
2372 ** Python 3 is now supported (in addition to Python 2.4 or later)
2374 ** New class gdb.Architecture exposes GDB's internal representation
2375 of architecture in the Python API.
2377 ** New method Frame.architecture returns the gdb.Architecture object
2378 corresponding to the frame's architecture.
2380 * New Python-based convenience functions:
2382 ** $_memeq(buf1, buf2, length)
2383 ** $_streq(str1, str2)
2385 ** $_regex(str, regex)
2387 * The 'cd' command now defaults to using '~' (the home directory) if not
2390 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2391 default for GCC since November 2000.
2393 * The command 'forward-search' can now be abbreviated as 'fo'.
2395 * The command 'info tracepoints' can now display 'installed on target'
2396 or 'not installed on target' for each non-pending location of tracepoint.
2398 * New configure options
2400 --enable-libmcheck/--disable-libmcheck
2401 By default, development versions are built with -lmcheck on hosts
2402 that support it, in order to help track memory corruption issues.
2403 Release versions, on the other hand, are built without -lmcheck
2404 by default. The --enable-libmcheck/--disable-libmcheck configure
2405 options allow the user to override that default.
2406 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2407 This configure option allows the user to build GDB with
2408 libbabeltrace using which GDB can read Common Trace Format data.
2410 * New commands (for set/show, see "New options" below)
2413 Catch signals. This is similar to "handle", but allows commands and
2414 conditions to be attached.
2417 List the BFDs known to GDB.
2419 python-interactive [command]
2421 Start a Python interactive prompt, or evaluate the optional command
2422 and print the result of expressions.
2425 "py" is a new alias for "python".
2427 enable type-printer [name]...
2428 disable type-printer [name]...
2429 Enable or disable type printers.
2433 ** For the Renesas Super-H architecture, the "regs" command has been removed
2434 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2439 set print type methods (on|off)
2440 show print type methods
2441 Control whether method declarations are displayed by "ptype".
2442 The default is to show them.
2444 set print type typedefs (on|off)
2445 show print type typedefs
2446 Control whether typedef definitions are displayed by "ptype".
2447 The default is to show them.
2449 set filename-display basename|relative|absolute
2450 show filename-display
2451 Control the way in which filenames is displayed.
2452 The default is "relative", which preserves previous behavior.
2454 set trace-buffer-size
2455 show trace-buffer-size
2456 Request target to change the size of trace buffer.
2458 set remote trace-buffer-size-packet auto|on|off
2459 show remote trace-buffer-size-packet
2460 Control the use of the remote protocol `QTBuffer:size' packet.
2464 Control display of debugging messages related to ARM AArch64.
2467 set debug coff-pe-read
2468 show debug coff-pe-read
2469 Control display of debugging messages related to reading of COFF/PE
2474 Control display of debugging messages related to Mach-O symbols
2477 set debug notification
2478 show debug notification
2479 Control display of debugging info for async remote notification.
2483 ** Command parameter changes are now notified using new async record
2484 "=cmd-param-changed".
2485 ** Trace frame changes caused by command "tfind" are now notified using
2486 new async record "=traceframe-changed".
2487 ** The creation, deletion and modification of trace state variables
2488 are now notified using new async records "=tsv-created",
2489 "=tsv-deleted" and "=tsv-modified".
2490 ** The start and stop of process record are now notified using new
2491 async record "=record-started" and "=record-stopped".
2492 ** Memory changes are now notified using new async record
2494 ** The data-disassemble command response will include a "fullname" field
2495 containing the absolute file name when source has been requested.
2496 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2497 command, to allow pattern filling of memory areas.
2498 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2499 library load/unload events.
2500 ** The response to breakpoint commands and breakpoint async records
2501 includes an "installed" field containing a boolean state about each
2502 non-pending tracepoint location is whether installed on target or not.
2503 ** Output of the "-trace-status" command includes a "trace-file" field
2504 containing the name of the trace file being examined. This field is
2505 optional, and only present when examining a trace file.
2506 ** The "fullname" field is now always present along with the "file" field,
2507 even if the file cannot be found by GDB.
2509 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2510 You must have the LZMA library available when configuring GDB for this
2511 feature to be enabled. For more information, see:
2512 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2514 * New remote packets
2517 Set the size of trace buffer. The remote stub reports support for this
2518 packet to gdb's qSupported query.
2521 Enable Branch Trace Store (BTS)-based branch tracing for the current
2522 thread. The remote stub reports support for this packet to gdb's
2526 Disable branch tracing for the current thread. The remote stub reports
2527 support for this packet to gdb's qSupported query.
2530 Read the traced branches for the current thread. The remote stub
2531 reports support for this packet to gdb's qSupported query.
2533 *** Changes in GDB 7.5
2535 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2536 for more x32 ABI info.
2538 * GDB now supports access to MIPS DSP registers on Linux targets.
2540 * GDB now supports debugging microMIPS binaries.
2542 * The "info os" command on GNU/Linux can now display information on
2543 several new classes of objects managed by the operating system:
2544 "info os procgroups" lists process groups
2545 "info os files" lists file descriptors
2546 "info os sockets" lists internet-domain sockets
2547 "info os shm" lists shared-memory regions
2548 "info os semaphores" lists semaphores
2549 "info os msg" lists message queues
2550 "info os modules" lists loaded kernel modules
2552 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2553 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2554 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2555 options and inspect the probe arguments using the new $_probe_arg family
2556 of convenience variables. You can obtain more information about SystemTap
2557 in <http://sourceware.org/systemtap/>.
2559 * GDB now supports reversible debugging on ARM, it allows you to
2560 debug basic ARM and THUMB instructions, and provides
2561 record/replay support.
2563 * The option "symbol-reloading" has been deleted as it is no longer used.
2567 ** GDB commands implemented in Python can now be put in command class
2570 ** The "maint set python print-stack on|off" is now deleted.
2572 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2573 apply "flag enum"-style pretty-printing to any enum.
2575 ** gdb.lookup_symbol can now work when there is no current frame.
2577 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2578 the source at which the symbol was defined.
2580 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2581 method 'value'. The former indicates whether the symbol needs a
2582 frame in order to compute its value, and the latter computes the
2585 ** A new method 'referenced_value' on gdb.Value objects which can
2586 dereference pointer as well as C++ reference values.
2588 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2589 which return the global and static blocks (as gdb.Block objects),
2590 of the underlying symbol table, respectively.
2592 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2593 object associated with a PC value.
2595 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2596 of the address range occupied by code for the current source line.
2598 * Go language support.
2599 GDB now supports debugging programs written in the Go programming
2602 * GDBserver now supports stdio connections.
2603 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2605 * The binary "gdbtui" can no longer be built or installed.
2606 Use "gdb -tui" instead.
2608 * GDB will now print "flag" enums specially. A flag enum is one where
2609 all the enumerator values have no bits in common when pairwise
2610 "and"ed. When printing a value whose type is a flag enum, GDB will
2611 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2612 (gdb) print (enum E) 3
2615 * The filename part of a linespec will now match trailing components
2616 of a source file name. For example, "break gcc/expr.c:1000" will
2617 now set a breakpoint in build/gcc/expr.c, but not
2618 build/libcpp/expr.c.
2620 * The "info proc" and "generate-core-file" commands will now also
2621 work on remote targets connected to GDBserver on Linux.
2623 * The command "info catch" has been removed. It has been disabled
2624 since December 2007.
2626 * The "catch exception" and "catch assert" commands now accept
2627 a condition at the end of the command, much like the "break"
2628 command does. For instance:
2630 (gdb) catch exception Constraint_Error if Barrier = True
2632 Previously, it was possible to add a condition to such catchpoints,
2633 but it had to be done as a second step, after the catchpoint had been
2634 created, using the "condition" command.
2636 * The "info static-tracepoint-marker" command will now also work on
2637 native Linux targets with in-process agent.
2639 * GDB can now set breakpoints on inlined functions.
2641 * The .gdb_index section has been updated to include symbols for
2642 inlined functions. GDB will ignore older .gdb_index sections by
2643 default, which could cause symbol files to be loaded more slowly
2644 until their .gdb_index sections can be recreated. The new command
2645 "set use-deprecated-index-sections on" will cause GDB to use any older
2646 .gdb_index sections it finds. This will restore performance, but the
2647 ability to set breakpoints on inlined functions will be lost in symbol
2648 files with older .gdb_index sections.
2650 The .gdb_index section has also been updated to record more information
2651 about each symbol. This speeds up the "info variables", "info functions"
2652 and "info types" commands when used with programs having the .gdb_index
2653 section, as well as speeding up debugging with shared libraries using
2654 the .gdb_index section.
2656 * Ada support for GDB/MI Variable Objects has been added.
2658 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2663 ** New command -info-os is the MI equivalent of "info os".
2665 ** Output logs ("set logging" and related) now include MI output.
2669 ** "set use-deprecated-index-sections on|off"
2670 "show use-deprecated-index-sections on|off"
2671 Controls the use of deprecated .gdb_index sections.
2673 ** "catch load" and "catch unload" can be used to stop when a shared
2674 library is loaded or unloaded, respectively.
2676 ** "enable count" can be used to auto-disable a breakpoint after
2679 ** "info vtbl" can be used to show the virtual method tables for
2680 C++ and Java objects.
2682 ** "explore" and its sub commands "explore value" and "explore type"
2683 can be used to recursively explore values and types of
2684 expressions. These commands are available only if GDB is
2685 configured with '--with-python'.
2687 ** "info auto-load" shows status of all kinds of auto-loaded files,
2688 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2689 sequences of commands files, "info auto-load python-scripts"
2690 shows status of auto-loading Python script files,
2691 "info auto-load local-gdbinit" shows status of loading init file
2692 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2693 status of inferior specific thread debugging shared library loading.
2695 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2696 and "show auto-load-scripts" commands have been deprecated, use their
2697 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2698 and "show auto-load python-scripts" counterparts instead.
2700 ** "dprintf location,format,args..." creates a dynamic printf, which
2701 is basically a breakpoint that does a printf and immediately
2702 resumes your program's execution, so it is like a printf that you
2703 can insert dynamically at runtime instead of at compiletime.
2705 ** "set print symbol"
2707 Controls whether GDB attempts to display the symbol, if any,
2708 corresponding to addresses it prints. This defaults to "on", but
2709 you can set it to "off" to restore GDB's previous behavior.
2711 * Deprecated commands
2713 ** For the Renesas Super-H architecture, the "regs" command has been
2714 deprecated, and "info all-registers" should be used instead.
2718 Renesas RL78 rl78-*-elf
2719 HP OpenVMS ia64 ia64-hp-openvms*
2721 * GDBserver supports evaluation of breakpoint conditions. When
2722 support is advertised by GDBserver, GDB may be told to send the
2723 breakpoint conditions in bytecode form to GDBserver. GDBserver
2724 will only report the breakpoint trigger to GDB when its condition
2729 set mips compression
2730 show mips compression
2731 Select the compressed ISA encoding used in functions that have no symbol
2732 information available. The encoding can be set to either of:
2735 and is updated automatically from ELF file flags if available.
2737 set breakpoint condition-evaluation
2738 show breakpoint condition-evaluation
2739 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2740 GDBserver ("target"). Default option "auto" chooses the most efficient
2742 This option can improve debugger efficiency depending on the speed of the
2746 Disable auto-loading globally.
2749 Show auto-loading setting of all kinds of auto-loaded files.
2751 set auto-load gdb-scripts on|off
2752 show auto-load gdb-scripts
2753 Control auto-loading of GDB canned sequences of commands files.
2755 set auto-load python-scripts on|off
2756 show auto-load python-scripts
2757 Control auto-loading of Python script files.
2759 set auto-load local-gdbinit on|off
2760 show auto-load local-gdbinit
2761 Control loading of init file (.gdbinit) from current directory.
2763 set auto-load libthread-db on|off
2764 show auto-load libthread-db
2765 Control auto-loading of inferior specific thread debugging shared library.
2767 set auto-load scripts-directory <dir1>[:<dir2>...]
2768 show auto-load scripts-directory
2769 Set a list of directories from which to load auto-loaded scripts.
2770 Automatically loaded Python scripts and GDB scripts are located in one
2771 of the directories listed by this option.
2772 The delimiter (':' above) may differ according to the host platform.
2774 set auto-load safe-path <dir1>[:<dir2>...]
2775 show auto-load safe-path
2776 Set a list of directories from which it is safe to auto-load files.
2777 The delimiter (':' above) may differ according to the host platform.
2779 set debug auto-load on|off
2780 show debug auto-load
2781 Control display of debugging info for auto-loading the files above.
2783 set dprintf-style gdb|call|agent
2785 Control the way in which a dynamic printf is performed; "gdb"
2786 requests a GDB printf command, while "call" causes dprintf to call a
2787 function in the inferior. "agent" requests that the target agent
2788 (such as GDBserver) do the printing.
2790 set dprintf-function <expr>
2791 show dprintf-function
2792 set dprintf-channel <expr>
2793 show dprintf-channel
2794 Set the function and optional first argument to the call when using
2795 the "call" style of dynamic printf.
2797 set disconnected-dprintf on|off
2798 show disconnected-dprintf
2799 Control whether agent-style dynamic printfs continue to be in effect
2800 after GDB disconnects.
2802 * New configure options
2804 --with-auto-load-dir
2805 Configure default value for the 'set auto-load scripts-directory'
2806 setting above. It defaults to '$debugdir:$datadir/auto-load',
2807 $debugdir representing global debugging info directories (available
2808 via 'show debug-file-directory') and $datadir representing GDB's data
2809 directory (available via 'show data-directory').
2811 --with-auto-load-safe-path
2812 Configure default value for the 'set auto-load safe-path' setting
2813 above. It defaults to the --with-auto-load-dir setting.
2815 --without-auto-load-safe-path
2816 Set 'set auto-load safe-path' to '/', effectively disabling this
2819 * New remote packets
2821 z0/z1 conditional breakpoints extension
2823 The z0/z1 breakpoint insertion packets have been extended to carry
2824 a list of conditional expressions over to the remote stub depending on the
2825 condition evaluation mode. The use of this extension can be controlled
2826 via the "set remote conditional-breakpoints-packet" command.
2830 Specify the signals which the remote stub may pass to the debugged
2831 program without GDB involvement.
2833 * New command line options
2835 --init-command=FILE, -ix Like --command, -x but execute it
2836 before loading inferior.
2837 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2838 execute it before loading inferior.
2840 *** Changes in GDB 7.4
2842 * GDB now handles ambiguous linespecs more consistently; the existing
2843 FILE:LINE support has been expanded to other types of linespecs. A
2844 breakpoint will now be set on all matching locations in all
2845 inferiors, and locations will be added or removed according to
2848 * GDB now allows you to skip uninteresting functions and files when
2849 stepping with the "skip function" and "skip file" commands.
2851 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2852 and "show remote hardware-watchpoint-length-limit". These allows to
2853 set or show the maximum length limit (in bytes) of a remote
2854 target hardware watchpoint.
2856 This allows e.g. to use "unlimited" hardware watchpoints with the
2857 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2858 watchpoints are slower than real hardware watchpoints but are
2859 significantly faster than gdb software watchpoints.
2863 ** The register_pretty_printer function in module gdb.printing now takes
2864 an optional `replace' argument. If True, the new printer replaces any
2867 ** The "maint set python print-stack on|off" command has been
2868 deprecated and will be deleted in GDB 7.5.
2869 A new command: "set python print-stack none|full|message" has
2870 replaced it. Additionally, the default for "print-stack" is
2871 now "message", which just prints the error message without
2874 ** A prompt substitution hook (prompt_hook) is now available to the
2877 ** A new Python module, gdb.prompt has been added to the GDB Python
2878 modules library. This module provides functionality for
2879 escape sequences in prompts (used by set/show
2880 extended-prompt). These escape sequences are replaced by their
2881 corresponding value.
2883 ** Python commands and convenience-functions located in
2884 'data-directory'/python/gdb/command and
2885 'data-directory'/python/gdb/function are now automatically loaded
2888 ** Blocks now provide four new attributes. global_block and
2889 static_block will return the global and static blocks
2890 respectively. is_static and is_global are boolean attributes
2891 that indicate if the block is one of those two types.
2893 ** Symbols now provide the "type" attribute, the type of the symbol.
2895 ** The "gdb.breakpoint" function has been deprecated in favor of
2898 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2899 of a function. This class is based on the "finish" command
2900 available in the CLI.
2902 ** Type objects for struct and union types now allow access to
2903 the fields using standard Python dictionary (mapping) methods.
2904 For example, "some_type['myfield']" now works, as does
2905 "some_type.items()".
2907 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2910 ** A new function, "deep_items" has been added to the gdb.types
2911 module in the GDB Python modules library. This function returns
2912 an iterator over the fields of a struct or union type. Unlike
2913 the standard Python "iteritems" method, it will recursively traverse
2914 any anonymous fields.
2918 ** "*stopped" events can report several new "reason"s, such as
2921 ** Breakpoint changes are now notified using new async records, like
2922 "=breakpoint-modified".
2924 ** New command -ada-task-info.
2926 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2927 $sdir specifies the default system locations of shared libraries.
2928 $pdir specifies the directory where the libpthread used by the application
2931 GDB no longer looks in $sdir and $pdir after it has searched the directories
2932 mentioned in libthread-db-search-path. If you want to search those
2933 directories, they must be specified in libthread-db-search-path.
2934 The default value of libthread-db-search-path on GNU/Linux and Solaris
2935 systems is now "$sdir:$pdir".
2937 $pdir is not supported by gdbserver, it is currently ignored.
2938 $sdir is supported by gdbserver.
2940 * New configure option --with-iconv-bin.
2941 When using the internationalization support like the one in the GNU C
2942 library, GDB will invoke the "iconv" program to get a list of supported
2943 character sets. If this program lives in a non-standard location, one can
2944 use this option to specify where to find it.
2946 * When natively debugging programs on PowerPC BookE processors running
2947 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2948 watchpoints, which specify a mask in addition to an address to watch.
2949 The mask specifies that some bits of an address (the bits which are
2950 reset in the mask) should be ignored when matching the address accessed
2951 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2952 section in the user manual for more details.
2954 * The new option --once causes GDBserver to stop listening for connections once
2955 the first connection is made. The listening port used by GDBserver will
2956 become available after that.
2958 * New commands "info macros" and "alias" have been added.
2960 * New function parameters suffix @entry specifies value of function parameter
2961 at the time the function got called. Entry values are available only since
2967 "!" is now an alias of the "shell" command.
2968 Note that no space is needed between "!" and SHELL COMMAND.
2972 watch EXPRESSION mask MASK_VALUE
2973 The watch command now supports the mask argument which allows creation
2974 of masked watchpoints, if the current architecture supports this feature.
2976 info auto-load-scripts [REGEXP]
2977 This command was formerly named "maintenance print section-scripts".
2978 It is now generally useful and is no longer a maintenance-only command.
2980 info macro [-all] [--] MACRO
2981 The info macro command has new options `-all' and `--'. The first for
2982 printing all definitions of a macro. The second for explicitly specifying
2983 the end of arguments and the beginning of the macro name in case the macro
2984 name starts with a hyphen.
2986 collect[/s] EXPRESSIONS
2987 The tracepoint collect command now takes an optional modifier "/s"
2988 that directs it to dereference pointer-to-character types and
2989 collect the bytes of memory up to a zero byte. The behavior is
2990 similar to what you see when you use the regular print command on a
2991 string. An optional integer following the "/s" sets a bound on the
2992 number of bytes that will be collected.
2995 The trace start command now interprets any supplied arguments as a
2996 note to be recorded with the trace run, with an effect similar to
2997 setting the variable trace-notes.
3000 The trace stop command now interprets any arguments as a note to be
3001 mentioned along with the tstatus report that the trace was stopped
3002 with a command. The effect is similar to setting the variable
3005 * Tracepoints can now be enabled and disabled at any time after a trace
3006 experiment has been started using the standard "enable" and "disable"
3007 commands. It is now possible to start a trace experiment with no enabled
3008 tracepoints; GDB will display a warning, but will allow the experiment to
3009 begin, assuming that tracepoints will be enabled as needed while the trace
3012 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3013 locations with 4-byte instructions, when they were previously
3014 limited to locations with instructions of 5 bytes or longer.
3018 set debug dwarf2-read
3019 show debug dwarf2-read
3020 Turns on or off display of debugging messages related to reading
3021 DWARF debug info. The default is off.
3023 set debug symtab-create
3024 show debug symtab-create
3025 Turns on or off display of debugging messages related to symbol table
3026 creation. The default is off.
3029 show extended-prompt
3030 Set the GDB prompt, and allow escape sequences to be inserted to
3031 display miscellaneous information (see 'help set extended-prompt'
3032 for the list of sequences). This prompt (and any information
3033 accessed through the escape sequences) is updated every time the
3034 prompt is displayed.
3036 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3037 show print entry-values
3038 Set printing of frame argument values at function entry. In some cases
3039 GDB can determine the value of function argument which was passed by the
3040 function caller, even if the value was modified inside the called function.
3042 set debug entry-values
3043 show debug entry-values
3044 Control display of debugging info for determining frame argument values at
3045 function entry and virtual tail call frames.
3047 set basenames-may-differ
3048 show basenames-may-differ
3049 Set whether a source file may have multiple base names.
3050 (A "base name" is the name of a file with the directory part removed.
3051 Example: The base name of "/home/user/hello.c" is "hello.c".)
3052 If set, GDB will canonicalize file names (e.g., expand symlinks)
3053 before comparing them. Canonicalization is an expensive operation,
3054 but it allows the same file be known by more than one base name.
3055 If not set (the default), all source files are assumed to have just
3056 one base name, and gdb will do file name comparisons more efficiently.
3062 Set a user name and notes for the current and any future trace runs.
3063 This is useful for long-running and/or disconnected traces, to
3064 inform others (or yourself) as to who is running the trace, supply
3065 contact information, or otherwise explain what is going on.
3067 set trace-stop-notes
3068 show trace-stop-notes
3069 Set a note attached to the trace run, that is displayed when the
3070 trace has been stopped by a tstop command. This is useful for
3071 instance as an explanation, if you are stopping a trace run that was
3072 started by someone else.
3074 * New remote packets
3078 Dynamically enable a tracepoint in a started trace experiment.
3082 Dynamically disable a tracepoint in a started trace experiment.
3086 Set the user and notes of the trace run.
3090 Query the current status of a tracepoint.
3094 Query the minimum length of instruction at which a fast tracepoint may
3097 * Dcache size (number of lines) and line-size are now runtime-configurable
3098 via "set dcache line" and "set dcache line-size" commands.
3102 Texas Instruments TMS320C6x tic6x-*-*
3106 Renesas RL78 rl78-*-elf
3108 *** Changes in GDB 7.3.1
3110 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3112 *** Changes in GDB 7.3
3114 * GDB has a new command: "thread find [REGEXP]".
3115 It finds the thread id whose name, target id, or thread extra info
3116 matches the given regular expression.
3118 * The "catch syscall" command now works on mips*-linux* targets.
3120 * The -data-disassemble MI command now supports modes 2 and 3 for
3121 dumping the instruction opcodes.
3123 * New command line options
3125 -data-directory DIR Specify DIR as the "data-directory".
3126 This is mostly for testing purposes.
3128 * The "maint set python auto-load on|off" command has been renamed to
3129 "set auto-load-scripts on|off".
3131 * GDB has a new command: "set directories".
3132 It is like the "dir" command except that it replaces the
3133 source path list instead of augmenting it.
3135 * GDB now understands thread names.
3137 On GNU/Linux, "info threads" will display the thread name as set by
3138 prctl or pthread_setname_np.
3140 There is also a new command, "thread name", which can be used to
3141 assign a name internally for GDB to display.
3144 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3145 has been integrated into GDB.
3149 ** The function gdb.Write now accepts an optional keyword 'stream'.
3150 This keyword, when provided, will direct the output to either
3151 stdout, stderr, or GDB's logging output.
3153 ** Parameters can now be be sub-classed in Python, and in particular
3154 you may implement the get_set_doc and get_show_doc functions.
3155 This improves how Parameter set/show documentation is processed
3156 and allows for more dynamic content.
3158 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3159 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3160 have an is_valid method.
3162 ** Breakpoints can now be sub-classed in Python, and in particular
3163 you may implement a 'stop' function that is executed each time
3164 the inferior reaches that breakpoint.
3166 ** New function gdb.lookup_global_symbol looks up a global symbol.
3168 ** GDB values in Python are now callable if the value represents a
3169 function. For example, if 'some_value' represents a function that
3170 takes two integer parameters and returns a value, you can call
3171 that function like so:
3173 result = some_value (10,20)
3175 ** Module gdb.types has been added.
3176 It contains a collection of utilities for working with gdb.Types objects:
3177 get_basic_type, has_field, make_enum_dict.
3179 ** Module gdb.printing has been added.
3180 It contains utilities for writing and registering pretty-printers.
3181 New classes: PrettyPrinter, SubPrettyPrinter,
3182 RegexpCollectionPrettyPrinter.
3183 New function: register_pretty_printer.
3185 ** New commands "info pretty-printers", "enable pretty-printer" and
3186 "disable pretty-printer" have been added.
3188 ** gdb.parameter("directories") is now available.
3190 ** New function gdb.newest_frame returns the newest frame in the
3193 ** The gdb.InferiorThread class has a new "name" attribute. This
3194 holds the thread's name.
3196 ** Python Support for Inferior events.
3197 Python scripts can add observers to be notified of events
3198 occurring in the process being debugged.
3199 The following events are currently supported:
3200 - gdb.events.cont Continue event.
3201 - gdb.events.exited Inferior exited event.
3202 - gdb.events.stop Signal received, and Breakpoint hit events.
3206 ** GDB now puts template parameters in scope when debugging in an
3207 instantiation. For example, if you have:
3209 template<int X> int func (void) { return X; }
3211 then if you step into func<5>, "print X" will show "5". This
3212 feature requires proper debuginfo support from the compiler; it
3213 was added to GCC 4.5.
3215 ** The motion commands "next", "finish", "until", and "advance" now
3216 work better when exceptions are thrown. In particular, GDB will
3217 no longer lose control of the inferior; instead, the GDB will
3218 stop the inferior at the point at which the exception is caught.
3219 This functionality requires a change in the exception handling
3220 code that was introduced in GCC 4.5.
3222 * GDB now follows GCC's rules on accessing volatile objects when
3223 reading or writing target state during expression evaluation.
3224 One notable difference to prior behavior is that "print x = 0"
3225 no longer generates a read of x; the value of the assignment is
3226 now always taken directly from the value being assigned.
3228 * GDB now has some support for using labels in the program's source in
3229 linespecs. For instance, you can use "advance label" to continue
3230 execution to a label.
3232 * GDB now has support for reading and writing a new .gdb_index
3233 section. This section holds a fast index of DWARF debugging
3234 information and can be used to greatly speed up GDB startup and
3235 operation. See the documentation for `save gdb-index' for details.
3237 * The "watch" command now accepts an optional "-location" argument.
3238 When used, this causes GDB to watch the memory referred to by the
3239 expression. Such a watchpoint is never deleted due to it going out
3242 * GDB now supports thread debugging of core dumps on GNU/Linux.
3244 GDB now activates thread debugging using the libthread_db library
3245 when debugging GNU/Linux core dumps, similarly to when debugging
3246 live processes. As a result, when debugging a core dump file, GDB
3247 is now able to display pthread_t ids of threads. For example, "info
3248 threads" shows the same output as when debugging the process when it
3249 was live. In earlier releases, you'd see something like this:
3252 * 1 LWP 6780 main () at main.c:10
3254 While now you see this:
3257 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3259 It is also now possible to inspect TLS variables when debugging core
3262 When debugging a core dump generated on a machine other than the one
3263 used to run GDB, you may need to point GDB at the correct
3264 libthread_db library with the "set libthread-db-search-path"
3265 command. See the user manual for more details on this command.
3267 * When natively debugging programs on PowerPC BookE processors running
3268 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3269 which stop execution of the inferior whenever it executes an instruction
3270 at any address within the specified range. See the "PowerPC Embedded"
3271 section in the user manual for more details.
3273 * New features in the GDB remote stub, GDBserver
3275 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3276 and i686 LynxOS (version 5.x).
3278 ** GDBserver is now supported on Blackfin Linux.
3280 * New native configurations
3282 ia64 HP-UX ia64-*-hpux*
3286 Analog Devices, Inc. Blackfin Processor bfin-*
3288 * Ada task switching is now supported on sparc-elf targets when
3289 debugging a program using the Ravenscar Profile. For more information,
3290 see the "Tasking Support when using the Ravenscar Profile" section
3291 in the GDB user manual.
3293 * Guile support was removed.
3295 * New features in the GNU simulator
3297 ** The --map-info flag lists all known core mappings.
3299 ** CFI flashes may be simulated via the "cfi" device.
3301 *** Changes in GDB 7.2
3303 * Shared library support for remote targets by default
3305 When GDB is configured for a generic, non-OS specific target, like
3306 for example, --target=arm-eabi or one of the many *-*-elf targets,
3307 GDB now queries remote stubs for loaded shared libraries using the
3308 `qXfer:libraries:read' packet. Previously, shared library support
3309 was always disabled for such configurations.
3313 ** Argument Dependent Lookup (ADL)
3315 In C++ ADL lookup directs function search to the namespaces of its
3316 arguments even if the namespace has not been imported.
3326 Here the compiler will search for `foo' in the namespace of 'b'
3327 and find A::foo. GDB now supports this. This construct is commonly
3328 used in the Standard Template Library for operators.
3330 ** Improved User Defined Operator Support
3332 In addition to member operators, GDB now supports lookup of operators
3333 defined in a namespace and imported with a `using' directive, operators
3334 defined in the global scope, operators imported implicitly from an
3335 anonymous namespace, and the ADL operators mentioned in the previous
3337 GDB now also supports proper overload resolution for all the previously
3338 mentioned flavors of operators.
3340 ** static const class members
3342 Printing of static const class members that are initialized in the
3343 class definition has been fixed.
3345 * Windows Thread Information Block access.
3347 On Windows targets, GDB now supports displaying the Windows Thread
3348 Information Block (TIB) structure. This structure is visible either
3349 by using the new command `info w32 thread-information-block' or, by
3350 dereferencing the new convenience variable named `$_tlb', a
3351 thread-specific pointer to the TIB. This feature is also supported
3352 when remote debugging using GDBserver.
3354 * Static tracepoints
3356 Static tracepoints are calls in the user program into a tracing
3357 library. One such library is a port of the LTTng kernel tracer to
3358 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3359 When debugging with GDBserver, GDB now supports combining the GDB
3360 tracepoint machinery with such libraries. For example: the user can
3361 use GDB to probe a static tracepoint marker (a call from the user
3362 program into the tracing library) with the new "strace" command (see
3363 "New commands" below). This creates a "static tracepoint" in the
3364 breakpoint list, that can be manipulated with the same feature set
3365 as fast and regular tracepoints. E.g., collect registers, local and
3366 global variables, collect trace state variables, and define
3367 tracepoint conditions. In addition, the user can collect extra
3368 static tracepoint marker specific data, by collecting the new
3369 $_sdata internal variable. When analyzing the trace buffer, you can
3370 inspect $_sdata like any other variable available to GDB. For more
3371 information, see the "Tracepoints" chapter in GDB user manual. New
3372 remote packets have been defined to support static tracepoints, see
3373 the "New remote packets" section below.
3375 * Better reconstruction of tracepoints after disconnected tracing
3377 GDB will attempt to download the original source form of tracepoint
3378 definitions when starting a trace run, and then will upload these
3379 upon reconnection to the target, resulting in a more accurate
3380 reconstruction of the tracepoints that are in use on the target.
3384 You can now exercise direct control over the ways that GDB can
3385 affect your program. For instance, you can disallow the setting of
3386 breakpoints, so that the program can run continuously (assuming
3387 non-stop mode). In addition, the "observer" variable is available
3388 to switch all of the different controls; in observer mode, GDB
3389 cannot affect the target's behavior at all, which is useful for
3390 tasks like diagnosing live systems in the field.
3392 * The new convenience variable $_thread holds the number of the
3395 * New remote packets
3399 Return the address of the Windows Thread Information Block of a given thread.
3403 In response to several of the tracepoint packets, the target may now
3404 also respond with a number of intermediate `qRelocInsn' request
3405 packets before the final result packet, to have GDB handle
3406 relocating an instruction to execute at a different address. This
3407 is particularly useful for stubs that support fast tracepoints. GDB
3408 reports support for this feature in the qSupported packet.
3412 List static tracepoint markers in the target program.
3416 List static tracepoint markers at a given address in the target
3419 qXfer:statictrace:read
3421 Read the static trace data collected (by a `collect $_sdata'
3422 tracepoint action). The remote stub reports support for this packet
3423 to gdb's qSupported query.
3427 Send the current settings of GDB's permission flags.
3431 Send part of the source (textual) form of a tracepoint definition,
3432 which includes location, conditional, and action list.
3434 * The source command now accepts a -s option to force searching for the
3435 script in the source search path even if the script name specifies
3438 * New features in the GDB remote stub, GDBserver
3440 - GDBserver now support tracepoints (including fast tracepoints, and
3441 static tracepoints). The feature is currently supported by the
3442 i386-linux and amd64-linux builds. See the "Tracepoints support
3443 in gdbserver" section in the manual for more information.
3445 GDBserver JIT compiles the tracepoint's conditional agent
3446 expression bytecode into native code whenever possible for low
3447 overhead dynamic tracepoints conditionals. For such tracepoints,
3448 an expression that examines program state is evaluated when the
3449 tracepoint is reached, in order to determine whether to capture
3450 trace data. If the condition is simple and false, processing the
3451 tracepoint finishes very quickly and no data is gathered.
3453 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3454 for static tracepoints support.
3456 - GDBserver now supports x86_64 Windows 64-bit debugging.
3458 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3459 it understands register description.
3461 * The --batch flag now disables pagination and queries.
3463 * X86 general purpose registers
3465 GDB now supports reading/writing byte, word and double-word x86
3466 general purpose registers directly. This means you can use, say,
3467 $ah or $ax to refer, respectively, to the byte register AH and
3468 16-bit word register AX that are actually portions of the 32-bit
3469 register EAX or 64-bit register RAX.
3471 * The `commands' command now accepts a range of breakpoints to modify.
3472 A plain `commands' following a command that creates multiple
3473 breakpoints affects all the breakpoints set by that command. This
3474 applies to breakpoints set by `rbreak', and also applies when a
3475 single `break' command creates multiple breakpoints (e.g.,
3476 breakpoints on overloaded c++ functions).
3478 * The `rbreak' command now accepts a filename specification as part of
3479 its argument, limiting the functions selected by the regex to those
3480 in the specified file.
3482 * Support for remote debugging Windows and SymbianOS shared libraries
3483 from Unix hosts has been improved. Non Windows GDB builds now can
3484 understand target reported file names that follow MS-DOS based file
3485 system semantics, such as file names that include drive letters and
3486 use the backslash character as directory separator. This makes it
3487 possible to transparently use the "set sysroot" and "set
3488 solib-search-path" on Unix hosts to point as host copies of the
3489 target's shared libraries. See the new command "set
3490 target-file-system-kind" described below, and the "Commands to
3491 specify files" section in the user manual for more information.
3495 eval template, expressions...
3496 Convert the values of one or more expressions under the control
3497 of the string template to a command line, and call it.
3499 set target-file-system-kind unix|dos-based|auto
3500 show target-file-system-kind
3501 Set or show the assumed file system kind for target reported file
3504 save breakpoints <filename>
3505 Save all current breakpoint definitions to a file suitable for use
3506 in a later debugging session. To read the saved breakpoint
3507 definitions, use the `source' command.
3509 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3512 info static-tracepoint-markers
3513 Display information about static tracepoint markers in the target.
3515 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3516 Define a static tracepoint by probing a marker at the given
3517 function, line, address, or marker ID.
3521 Enable and disable observer mode.
3523 set may-write-registers on|off
3524 set may-write-memory on|off
3525 set may-insert-breakpoints on|off
3526 set may-insert-tracepoints on|off
3527 set may-insert-fast-tracepoints on|off
3528 set may-interrupt on|off
3529 Set individual permissions for GDB effects on the target. Note that
3530 some of these settings can have undesirable or surprising
3531 consequences, particularly when changed in the middle of a session.
3532 For instance, disabling the writing of memory can prevent
3533 breakpoints from being inserted, cause single-stepping to fail, or
3534 even crash your program, if you disable after breakpoints have been
3535 inserted. However, GDB should not crash.
3537 set record memory-query on|off
3538 show record memory-query
3539 Control whether to stop the inferior if memory changes caused
3540 by an instruction cannot be recorded.
3545 The disassemble command now supports "start,+length" form of two arguments.
3549 ** GDB now provides a new directory location, called the python directory,
3550 where Python scripts written for GDB can be installed. The location
3551 of that directory is <data-directory>/python, where <data-directory>
3552 is the GDB data directory. For more details, see section `Scripting
3553 GDB using Python' in the manual.
3555 ** The GDB Python API now has access to breakpoints, symbols, symbol
3556 tables, program spaces, inferiors, threads and frame's code blocks.
3557 Additionally, GDB Parameters can now be created from the API, and
3558 manipulated via set/show in the CLI.
3560 ** New functions gdb.target_charset, gdb.target_wide_charset,
3561 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3563 ** New exception gdb.GdbError.
3565 ** Pretty-printers are now also looked up in the current program space.
3567 ** Pretty-printers can now be individually enabled and disabled.
3569 ** GDB now looks for names of Python scripts to auto-load in a
3570 special section named `.debug_gdb_scripts', in addition to looking
3571 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3573 * Tracepoint actions were unified with breakpoint commands. In particular,
3574 there are no longer differences in "info break" output for breakpoints and
3575 tracepoints and the "commands" command can be used for both tracepoints and
3576 regular breakpoints.
3580 ARM Symbian arm*-*-symbianelf*
3582 * D language support.
3583 GDB now supports debugging programs written in the D programming
3586 * GDB now supports the extended ptrace interface for PowerPC which is
3587 available since Linux kernel version 2.6.34. This automatically enables
3588 any hardware breakpoints and additional hardware watchpoints available in
3589 the processor. The old ptrace interface exposes just one hardware
3590 watchpoint and no hardware breakpoints.
3592 * GDB is now able to use the Data Value Compare (DVC) register available on
3593 embedded PowerPC processors to implement in hardware simple watchpoint
3594 conditions of the form:
3596 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3598 This works in native GDB running on Linux kernels with the extended ptrace
3599 interface mentioned above.
3601 *** Changes in GDB 7.1
3605 ** Namespace Support
3607 GDB now supports importing of namespaces in C++. This enables the
3608 user to inspect variables from imported namespaces. Support for
3609 namepace aliasing has also been added. So, if a namespace is
3610 aliased in the current scope (e.g. namepace C=A; ) the user can
3611 print variables using the alias (e.g. (gdb) print C::x).
3615 All known bugs relating to the printing of virtual base class were
3616 fixed. It is now possible to call overloaded static methods using a
3621 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3622 and reinterpret_cast<> are now handled by the C++ expression parser.
3626 Xilinx MicroBlaze microblaze-*-*
3631 Xilinx MicroBlaze microblaze
3634 * Multi-program debugging.
3636 GDB now has support for multi-program (a.k.a. multi-executable or
3637 multi-exec) debugging. This allows for debugging multiple inferiors
3638 simultaneously each running a different program under the same GDB
3639 session. See "Debugging Multiple Inferiors and Programs" in the
3640 manual for more information. This implied some user visible changes
3641 in the multi-inferior support. For example, "info inferiors" now
3642 lists inferiors that are not running yet or that have exited
3643 already. See also "New commands" and "New options" below.
3645 * New tracing features
3647 GDB's tracepoint facility now includes several new features:
3649 ** Trace state variables
3651 GDB tracepoints now include support for trace state variables, which
3652 are variables managed by the target agent during a tracing
3653 experiment. They are useful for tracepoints that trigger each
3654 other, so for instance one tracepoint can count hits in a variable,
3655 and then a second tracepoint has a condition that is true when the
3656 count reaches a particular value. Trace state variables share the
3657 $-syntax of GDB convenience variables, and can appear in both
3658 tracepoint actions and condition expressions. Use the "tvariable"
3659 command to create, and "info tvariables" to view; see "Trace State
3660 Variables" in the manual for more detail.
3664 GDB now includes an option for defining fast tracepoints, which
3665 targets may implement more efficiently, such as by installing a jump
3666 into the target agent rather than a trap instruction. The resulting
3667 speedup can be by two orders of magnitude or more, although the
3668 tradeoff is that some program locations on some target architectures
3669 might not allow fast tracepoint installation, for instance if the
3670 instruction to be replaced is shorter than the jump. To request a
3671 fast tracepoint, use the "ftrace" command, with syntax identical to
3672 the regular trace command.
3674 ** Disconnected tracing
3676 It is now possible to detach GDB from the target while it is running
3677 a trace experiment, then reconnect later to see how the experiment
3678 is going. In addition, a new variable disconnected-tracing lets you
3679 tell the target agent whether to continue running a trace if the
3680 connection is lost unexpectedly.
3684 GDB now has the ability to save the trace buffer into a file, and
3685 then use that file as a target, similarly to you can do with
3686 corefiles. You can select trace frames, print data that was
3687 collected in them, and use tstatus to display the state of the
3688 tracing run at the moment that it was saved. To create a trace
3689 file, use "tsave <filename>", and to use it, do "target tfile
3692 ** Circular trace buffer
3694 You can ask the target agent to handle the trace buffer as a
3695 circular buffer, discarding the oldest trace frames to make room for
3696 newer ones, by setting circular-trace-buffer to on. This feature may
3697 not be available for all target agents.
3702 The disassemble command, when invoked with two arguments, now requires
3703 the arguments to be comma-separated.
3706 The info variables command now displays variable definitions. Files
3707 which only declare a variable are not shown.
3710 The source command is now capable of sourcing Python scripts.
3711 This feature is dependent on the debugger being build with Python
3714 Related to this enhancement is also the introduction of a new command
3715 "set script-extension" (see below).
3717 * New commands (for set/show, see "New options" below)
3719 record save [<FILENAME>]
3720 Save a file (in core file format) containing the process record
3721 execution log for replay debugging at a later time.
3723 record restore <FILENAME>
3724 Restore the process record execution log that was saved at an
3725 earlier time, for replay debugging.
3727 add-inferior [-copies <N>] [-exec <FILENAME>]
3730 clone-inferior [-copies <N>] [ID]
3731 Make a new inferior ready to execute the same program another
3732 inferior has loaded.
3737 maint info program-spaces
3738 List the program spaces loaded into GDB.
3740 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3741 show remote interrupt-sequence
3742 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3743 as the sequence to the remote target in order to interrupt the execution.
3744 Ctrl-C is a default. Some system prefers BREAK which is high level of
3745 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3746 Magic SysRq g. It is BREAK signal and character 'g'.
3748 set remote interrupt-on-connect [on | off]
3749 show remote interrupt-on-connect
3750 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3751 remote target when gdb connects to it. This is needed when you debug
3754 set remotebreak [on | off]
3756 Deprecated. Use "set/show remote interrupt-sequence" instead.
3758 tvariable $NAME [ = EXP ]
3759 Create or modify a trace state variable.
3762 List trace state variables and their values.
3764 delete tvariable $NAME ...
3765 Delete one or more trace state variables.
3768 Evaluate the given expressions without collecting anything into the
3769 trace buffer. (Valid in tracepoint actions only.)
3771 ftrace FN / FILE:LINE / *ADDR
3772 Define a fast tracepoint at the given function, line, or address.
3774 * New expression syntax
3776 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3777 GDB now parses 0b101010 identically with 42.
3781 set follow-exec-mode new|same
3782 show follow-exec-mode
3783 Control whether GDB reuses the same inferior across an exec call or
3784 creates a new one. This is useful to be able to restart the old
3785 executable after the inferior having done an exec call.
3787 set default-collect EXPR, ...
3788 show default-collect
3789 Define a list of expressions to be collected at each tracepoint.
3790 This is a useful way to ensure essential items are not overlooked,
3791 such as registers or a critical global variable.
3793 set disconnected-tracing
3794 show disconnected-tracing
3795 If set to 1, the target is instructed to continue tracing if it
3796 loses its connection to GDB. If 0, the target is to stop tracing
3799 set circular-trace-buffer
3800 show circular-trace-buffer
3801 If set to on, the target is instructed to use a circular trace buffer
3802 and discard the oldest trace frames instead of stopping the trace due
3803 to a full trace buffer. If set to off, the trace stops when the buffer
3804 fills up. Some targets may not support this.
3806 set script-extension off|soft|strict
3807 show script-extension
3808 If set to "off", the debugger does not perform any script language
3809 recognition, and all sourced files are assumed to be GDB scripts.
3810 If set to "soft" (the default), files are sourced according to
3811 filename extension, falling back to GDB scripts if the first
3813 If set to "strict", files are sourced according to filename extension.
3815 set ada trust-PAD-over-XVS on|off
3816 show ada trust-PAD-over-XVS
3817 If off, activate a workaround against a bug in the debugging information
3818 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3819 the GCC sources for more information about the GNAT encoding and
3820 PAD types in particular). It is always safe to set this option to
3821 off, but this introduces a slight performance penalty. The default
3824 * Python API Improvements
3826 ** GDB provides the new class gdb.LazyString. This is useful in
3827 some pretty-printing cases. The new method gdb.Value.lazy_string
3828 provides a simple way to create objects of this type.
3830 ** The fields returned by gdb.Type.fields now have an
3831 `is_base_class' attribute.
3833 ** The new method gdb.Type.range returns the range of an array type.
3835 ** The new method gdb.parse_and_eval can be used to parse and
3836 evaluate an expression.
3838 * New remote packets
3841 Define a trace state variable.
3844 Get the current value of a trace state variable.
3847 Set desired tracing behavior upon disconnection.
3850 Set the trace buffer to be linear or circular.
3853 Get data about the tracepoints currently in use.
3857 Process record now works correctly with hardware watchpoints.
3859 Multiple bug fixes have been made to the mips-irix port, making it
3860 much more reliable. In particular:
3861 - Debugging threaded applications is now possible again. Previously,
3862 GDB would hang while starting the program, or while waiting for
3863 the program to stop at a breakpoint.
3864 - Attaching to a running process no longer hangs.
3865 - An error occurring while loading a core file has been fixed.
3866 - Changing the value of the PC register now works again. This fixes
3867 problems observed when using the "jump" command, or when calling
3868 a function from GDB, or even when assigning a new value to $pc.
3869 - With the "finish" and "return" commands, the return value for functions
3870 returning a small array is now correctly printed.
3871 - It is now possible to break on shared library code which gets executed
3872 during a shared library init phase (code executed while executing
3873 their .init section). Previously, the breakpoint would have no effect.
3874 - GDB is now able to backtrace through the signal handler for
3875 non-threaded programs.
3877 PIE (Position Independent Executable) programs debugging is now supported.
3878 This includes debugging execution of PIC (Position Independent Code) shared
3879 libraries although for that, it should be possible to run such libraries as an
3882 *** Changes in GDB 7.0
3884 * GDB now has an interface for JIT compilation. Applications that
3885 dynamically generate code can create symbol files in memory and register
3886 them with GDB. For users, the feature should work transparently, and
3887 for JIT developers, the interface is documented in the GDB manual in the
3888 "JIT Compilation Interface" chapter.
3890 * Tracepoints may now be conditional. The syntax is as for
3891 breakpoints; either an "if" clause appended to the "trace" command,
3892 or the "condition" command is available. GDB sends the condition to
3893 the target for evaluation using the same bytecode format as is used
3894 for tracepoint actions.
3896 * The disassemble command now supports: an optional /r modifier, print the
3897 raw instructions in hex as well as in symbolic form, and an optional /m
3898 modifier to print mixed source+assembly.
3900 * Process record and replay
3902 In a architecture environment that supports ``process record and
3903 replay'', ``process record and replay'' target can record a log of
3904 the process execution, and replay it with both forward and reverse
3907 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3908 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3909 set execution-direction {forward|reverse}, for targets that support
3912 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3913 feature is available with a native GDB running on kernel version
3916 * GDB now has support for multi-byte and wide character sets on the
3917 target. Strings whose character type is wchar_t, char16_t, or
3918 char32_t are now correctly printed. GDB supports wide- and unicode-
3919 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3920 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3921 `printf'. This feature requires iconv to work properly; if your
3922 system does not have a working iconv, GDB can use GNU libiconv. See
3923 the installation instructions for more information.
3925 * GDB now supports automatic retrieval of shared library files from
3926 remote targets. To use this feature, specify a system root that begins
3927 with the `remote:' prefix, either via the `set sysroot' command or via
3928 the `--with-sysroot' configure-time option.
3930 * "info sharedlibrary" now takes an optional regex of libraries to show,
3931 and it now reports if a shared library has no debugging information.
3933 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3934 now complete on file names.
3936 * When completing in expressions, gdb will attempt to limit
3937 completions to allowable structure or union fields, where appropriate.
3938 For instance, consider:
3940 # struct example { int f1; double f2; };
3941 # struct example variable;
3944 If the user types TAB at the end of this command line, the available
3945 completions will be "f1" and "f2".
3947 * Inlined functions are now supported. They show up in backtraces, and
3948 the "step", "next", and "finish" commands handle them automatically.
3950 * GDB now supports the token-splicing (##) and stringification (#)
3951 operators when expanding macros. It also supports variable-arity
3954 * GDB now supports inspecting extra signal information, exported by
3955 the new $_siginfo convenience variable. The feature is currently
3956 implemented on linux ARM, i386 and amd64.
3958 * GDB can now display the VFP floating point registers and NEON vector
3959 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3960 can provide these registers (requires Linux 2.6.30 or later). Remote
3961 and simulator targets may also provide them.
3963 * New remote packets
3966 Search memory for a sequence of bytes.
3969 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3970 operation over reliable transport links. Use of this packet is
3971 controlled by the `set remote noack-packet' command.
3974 Kill the process with the specified process ID. Use this in preference
3975 to `k' when multiprocess protocol extensions are supported.
3978 Obtains additional operating system information
3982 Read or write additional signal information.
3984 * Removed remote protocol undocumented extension
3986 An undocumented extension to the remote protocol's `S' stop reply
3987 packet that permited the stub to pass a process id was removed.
3988 Remote servers should use the `T' stop reply packet instead.
3990 * GDB now supports multiple function calling conventions according to the
3991 DWARF-2 DW_AT_calling_convention function attribute.
3993 * The SH target utilizes the aforementioned change to distinguish between gcc
3994 and Renesas calling convention. It also adds the new CLI commands
3995 `set/show sh calling-convention'.
3997 * GDB can now read compressed debug sections, as produced by GNU gold
3998 with the --compress-debug-sections=zlib flag.
4000 * 64-bit core files are now supported on AIX.
4002 * Thread switching is now supported on Tru64.
4004 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4005 which will be allocated using malloc later in program execution.
4007 * The qXfer:libraries:read remote procotol packet now allows passing a
4008 list of section offsets.
4010 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4011 conditions handling signals delivered during attach or thread creation
4012 have also been fixed.
4014 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4015 From the user's standpoint, all unqualified instances of True and False
4016 are treated as the standard definitions, regardless of context.
4018 * GDB now parses C++ symbol and type names more flexibly. For
4021 template<typename T> class C { };
4024 GDB will now correctly handle all of:
4026 ptype C<char const *>
4027 ptype C<char const*>
4028 ptype C<const char *>
4029 ptype C<const char*>
4031 * New features in the GDB remote stub, gdbserver
4033 - The "--wrapper" command-line argument tells gdbserver to use a
4034 wrapper program to launch programs for debugging.
4036 - On PowerPC and S/390 targets, it is now possible to use a single
4037 gdbserver executable to debug both 32-bit and 64-bit programs.
4038 (This requires gdbserver itself to be built as a 64-bit executable.)
4040 - gdbserver uses the new noack protocol mode for TCP connections to
4041 reduce communications latency, if also supported and enabled in GDB.
4043 - Support for the sparc64-linux-gnu target is now included in
4046 - The amd64-linux build of gdbserver now supports debugging both
4047 32-bit and 64-bit programs.
4049 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4050 now support hardware watchpoints, and will use them automatically
4055 GDB now has support for scripting using Python. Whether this is
4056 available is determined at configure time.
4058 New GDB commands can now be written in Python.
4060 * Ada tasking support
4062 Ada tasks can now be inspected in GDB. The following commands have
4066 Print the list of Ada tasks.
4068 Print detailed information about task number N.
4070 Print the task number of the current task.
4072 Switch the context of debugging to task number N.
4074 * Support for user-defined prefixed commands. The "define" command can
4075 add new commands to existing prefixes, e.g. "target".
4077 * Multi-inferior, multi-process debugging.
4079 GDB now has generalized support for multi-inferior debugging. See
4080 "Debugging Multiple Inferiors" in the manual for more information.
4081 Although availability still depends on target support, the command
4082 set is more uniform now. The GNU/Linux specific multi-forks support
4083 has been migrated to this new framework. This implied some user
4084 visible changes; see "New commands" and also "Removed commands"
4087 * Target descriptions can now describe the target OS ABI. See the
4088 "Target Description Format" section in the user manual for more
4091 * Target descriptions can now describe "compatible" architectures
4092 to indicate that the target can execute applications for a different
4093 architecture in addition to those for the main target architecture.
4094 See the "Target Description Format" section in the user manual for
4097 * Multi-architecture debugging.
4099 GDB now includes general supports for debugging applications on
4100 hybrid systems that use more than one single processor architecture
4101 at the same time. Each such hybrid architecture still requires
4102 specific support to be added. The only hybrid architecture supported
4103 in this version of GDB is the Cell Broadband Engine.
4105 * GDB now supports integrated debugging of Cell/B.E. applications that
4106 use both the PPU and SPU architectures. To enable support for hybrid
4107 Cell/B.E. debugging, you need to configure GDB to support both the
4108 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4109 --enable-targets configure option.
4111 * Non-stop mode debugging.
4113 For some targets, GDB now supports an optional mode of operation in
4114 which you can examine stopped threads while other threads continue
4115 to execute freely. This is referred to as non-stop mode, with the
4116 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4117 section in the user manual for more information.
4119 To be able to support remote non-stop debugging, a remote stub needs
4120 to implement the non-stop mode remote protocol extensions, as
4121 described in the "Remote Non-Stop" section of the user manual. The
4122 GDB remote stub, gdbserver, has been adjusted to support these
4123 extensions on linux targets.
4125 * New commands (for set/show, see "New options" below)
4127 catch syscall [NAME(S) | NUMBER(S)]
4128 Catch system calls. Arguments, which should be names of system
4129 calls or their numbers, mean catch only those syscalls. Without
4130 arguments, every syscall will be caught. When the inferior issues
4131 any of the specified syscalls, GDB will stop and announce the system
4132 call, both when it is called and when its call returns. This
4133 feature is currently available with a native GDB running on the
4134 Linux Kernel, under the following architectures: x86, x86_64,
4135 PowerPC and PowerPC64.
4137 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4139 Search memory for a sequence of bytes.
4141 maint set python print-stack
4142 maint show python print-stack
4143 Show a stack trace when an error is encountered in a Python script.
4146 Invoke CODE by passing it to the Python interpreter.
4151 These allow macros to be defined, undefined, and listed
4155 Show operating system information about processes.
4158 List the inferiors currently under GDB's control.
4161 Switch focus to inferior number NUM.
4164 Detach from inferior number NUM.
4167 Kill inferior number NUM.
4171 set spu stop-on-load
4172 show spu stop-on-load
4173 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4175 set spu auto-flush-cache
4176 show spu auto-flush-cache
4177 Control whether to automatically flush the software-managed cache
4178 during Cell/B.E. debugging.
4180 set sh calling-convention
4181 show sh calling-convention
4182 Control the calling convention used when calling SH target functions.
4185 show debug timestamp
4186 Control display of timestamps with GDB debugging output.
4188 set disassemble-next-line
4189 show disassemble-next-line
4190 Control display of disassembled source lines or instructions when
4193 set remote noack-packet
4194 show remote noack-packet
4195 Set/show the use of remote protocol QStartNoAckMode packet. See above
4196 under "New remote packets."
4198 set remote query-attached-packet
4199 show remote query-attached-packet
4200 Control use of remote protocol `qAttached' (query-attached) packet.
4202 set remote read-siginfo-object
4203 show remote read-siginfo-object
4204 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4207 set remote write-siginfo-object
4208 show remote write-siginfo-object
4209 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4212 set remote reverse-continue
4213 show remote reverse-continue
4214 Control use of remote protocol 'bc' (reverse-continue) packet.
4216 set remote reverse-step
4217 show remote reverse-step
4218 Control use of remote protocol 'bs' (reverse-step) packet.
4220 set displaced-stepping
4221 show displaced-stepping
4222 Control displaced stepping mode. Displaced stepping is a way to
4223 single-step over breakpoints without removing them from the debuggee.
4224 Also known as "out-of-line single-stepping".
4227 show debug displaced
4228 Control display of debugging info for displaced stepping.
4230 maint set internal-error
4231 maint show internal-error
4232 Control what GDB does when an internal error is detected.
4234 maint set internal-warning
4235 maint show internal-warning
4236 Control what GDB does when an internal warning is detected.
4241 Use a wrapper program to launch programs for debugging.
4243 set multiple-symbols (all|ask|cancel)
4244 show multiple-symbols
4245 The value of this variable can be changed to adjust the debugger behavior
4246 when an expression or a breakpoint location contains an ambiguous symbol
4247 name (an overloaded function name, for instance).
4249 set breakpoint always-inserted
4250 show breakpoint always-inserted
4251 Keep breakpoints always inserted in the target, as opposed to inserting
4252 them when resuming the target, and removing them when the target stops.
4253 This option can improve debugger performance on slow remote targets.
4255 set arm fallback-mode (arm|thumb|auto)
4256 show arm fallback-mode
4257 set arm force-mode (arm|thumb|auto)
4259 These commands control how ARM GDB determines whether instructions
4260 are ARM or Thumb. The default for both settings is auto, which uses
4261 the current CPSR value for instructions without symbols; previous
4262 versions of GDB behaved as if "set arm fallback-mode arm".
4264 set disable-randomization
4265 show disable-randomization
4266 Standalone programs run with the virtual address space randomization enabled
4267 by default on some platforms. This option keeps the addresses stable across
4268 multiple debugging sessions.
4272 Control whether other threads are stopped or not when some thread hits
4277 Requests that asynchronous execution is enabled in the target, if available.
4278 In this case, it's possible to resume target in the background, and interact
4279 with GDB while the target is running. "show target-async" displays the
4280 current state of asynchronous execution of the target.
4282 set target-wide-charset
4283 show target-wide-charset
4284 The target-wide-charset is the name of the character set that GDB
4285 uses when printing characters whose type is wchar_t.
4287 set tcp auto-retry (on|off)
4289 set tcp connect-timeout
4290 show tcp connect-timeout
4291 These commands allow GDB to retry failed TCP connections to a remote stub
4292 with a specified timeout period; this is useful if the stub is launched
4293 in parallel with GDB but may not be ready to accept connections immediately.
4295 set libthread-db-search-path
4296 show libthread-db-search-path
4297 Control list of directories which GDB will search for appropriate
4300 set schedule-multiple (on|off)
4301 show schedule-multiple
4302 Allow GDB to resume all threads of all processes or only threads of
4303 the current process.
4307 Use more aggressive caching for accesses to the stack. This improves
4308 performance of remote debugging (particularly backtraces) without
4309 affecting correctness.
4311 set interactive-mode (on|off|auto)
4312 show interactive-mode
4313 Control whether GDB runs in interactive mode (on) or not (off).
4314 When in interactive mode, GDB waits for the user to answer all
4315 queries. Otherwise, GDB does not wait and assumes the default
4316 answer. When set to auto (the default), GDB determines which
4317 mode to use based on the stdin settings.
4322 For program forks, this is replaced by the new more generic `info
4323 inferiors' command. To list checkpoints, you can still use the
4324 `info checkpoints' command, which was an alias for the `info forks'
4328 Replaced by the new `inferior' command. To switch between
4329 checkpoints, you can still use the `restart' command, which was an
4330 alias for the `fork' command.
4333 This is removed, since some targets don't have a notion of
4334 processes. To switch between processes, you can still use the
4335 `inferior' command using GDB's own inferior number.
4338 For program forks, this is replaced by the new more generic `kill
4339 inferior' command. To delete a checkpoint, you can still use the
4340 `delete checkpoint' command, which was an alias for the `delete
4344 For program forks, this is replaced by the new more generic `detach
4345 inferior' command. To detach a checkpoint, you can still use the
4346 `detach checkpoint' command, which was an alias for the `detach
4349 * New native configurations
4351 x86/x86_64 Darwin i[34567]86-*-darwin*
4353 x86_64 MinGW x86_64-*-mingw*
4357 Lattice Mico32 lm32-*
4358 x86 DICOS i[34567]86-*-dicos*
4359 x86_64 DICOS x86_64-*-dicos*
4362 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4363 (mingw32ce) debugging.
4369 These commands were actually not implemented on any target.
4371 *** Changes in GDB 6.8
4373 * New native configurations
4375 NetBSD/hppa hppa*-*netbsd*
4376 Xtensa GNU/Linux xtensa*-*-linux*
4380 NetBSD/hppa hppa*-*-netbsd*
4381 Xtensa GNU/Lunux xtensa*-*-linux*
4383 * Change in command line behavior -- corefiles vs. process ids.
4385 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4386 attaching to process NUMBER fails, GDB no longer attempts to open a
4387 core file named NUMBER. Attaching to a program using the -c option
4388 is no longer supported. Instead, use the '-p' or '--pid' options.
4390 * GDB can now be built as a native debugger for debugging Windows x86
4391 (mingw32) Portable Executable (PE) programs.
4393 * Pending breakpoints no longer change their number when their address
4396 * GDB now supports breakpoints with multiple locations,
4397 including breakpoints on C++ constructors, inside C++ templates,
4398 and in inlined functions.
4400 * GDB's ability to debug optimized code has been improved. GDB more
4401 accurately identifies function bodies and lexical blocks that occupy
4402 more than one contiguous range of addresses.
4404 * Target descriptions can now describe registers for PowerPC.
4406 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4407 registers on PowerPC targets.
4409 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4410 targets even when the libthread_db library is not available.
4412 * The GDB remote stub, gdbserver, now supports the new file transfer
4413 commands (remote put, remote get, and remote delete).
4415 * The GDB remote stub, gdbserver, now supports run and attach in
4416 extended-remote mode.
4418 * hppa*64*-*-hpux11* target broken
4419 The debugger is unable to start a program and fails with the following
4420 error: "Error trying to get information about dynamic linker".
4421 The gdb-6.7 release is also affected.
4423 * GDB now supports the --enable-targets= configure option to allow
4424 building a single GDB executable that supports multiple remote
4425 target architectures.
4427 * GDB now supports debugging C and C++ programs which use the
4428 Decimal Floating Point extension. In addition, the PowerPC target
4429 now has a set of pseudo-registers to inspect decimal float values
4430 stored in two consecutive float registers.
4432 * The -break-insert MI command can optionally create pending
4435 * Improved support for debugging Ada
4436 Many improvements to the Ada language support have been made. These
4438 - Better support for Ada2005 interface types
4439 - Improved handling of arrays and slices in general
4440 - Better support for Taft-amendment types
4441 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4443 - Improved command completion in Ada
4446 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4451 set print frame-arguments (all|scalars|none)
4452 show print frame-arguments
4453 The value of this variable can be changed to control which argument
4454 values should be printed by the debugger when displaying a frame.
4459 Transfer files to and from a remote target, and delete remote files.
4466 Transfer files to and from a remote target, and delete remote files.
4468 * New remote packets
4475 Open, close, read, write, and delete files on the remote system.
4478 Attach to an existing process on the remote system, in extended-remote
4482 Run a new process on the remote system, in extended-remote mode.
4484 *** Changes in GDB 6.7
4486 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4487 bfd, libiberty and opcodes, as revealed by static analysis donated by
4488 Coverity, Inc. (http://scan.coverity.com).
4490 * When looking up multiply-defined global symbols, GDB will now prefer the
4491 symbol definition in the current shared library if it was built using the
4492 -Bsymbolic linker option.
4494 * When the Text User Interface (TUI) is not configured, GDB will now
4495 recognize the -tui command-line option and print a message that the TUI
4498 * The GDB remote stub, gdbserver, now has lower overhead for high
4499 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4501 * GDB for MIPS targets now autodetects whether a remote target provides
4502 32-bit or 64-bit register values.
4504 * Support for C++ member pointers has been improved.
4506 * GDB now understands XML target descriptions, which specify the
4507 target's overall architecture. GDB can read a description from
4508 a local file or over the remote serial protocol.
4510 * Vectors of single-byte data use a new integer type which is not
4511 automatically displayed as character or string data.
4513 * The /s format now works with the print command. It displays
4514 arrays of single-byte integers and pointers to single-byte integers
4517 * Target descriptions can now describe target-specific registers,
4518 for architectures which have implemented the support (currently
4519 only ARM, M68K, and MIPS).
4521 * GDB and the GDB remote stub, gdbserver, now support the XScale
4524 * The GDB remote stub, gdbserver, has been updated to support
4525 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4526 has been rewritten to use the standard GDB remote protocol.
4528 * GDB can now step into C++ functions which are called through thunks.
4530 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4532 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4533 layout. It also supports a TextSeg= and DataSeg= response when only
4534 segment base addresses (rather than offsets) are available.
4536 * The /i format now outputs any trailing branch delay slot instructions
4537 immediately following the last instruction within the count specified.
4539 * The GDB remote protocol "T" stop reply packet now supports a
4540 "library" response. Combined with the new "qXfer:libraries:read"
4541 packet, this response allows GDB to debug shared libraries on targets
4542 where the operating system manages the list of loaded libraries (e.g.
4543 Windows and SymbianOS).
4545 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4546 (DLLs) on Windows and Windows CE targets.
4548 * GDB now supports a faster verification that a .debug file matches its binary
4549 according to its build-id signature, if the signature is present.
4555 Enable or disable hardware flow control (RTS/CTS) on the serial port
4556 when debugging using remote targets.
4558 set mem inaccessible-by-default
4559 show mem inaccessible-by-default
4560 If the target supplies a memory map, for instance via the remote
4561 protocol's "qXfer:memory-map:read" packet, setting this variable
4562 prevents GDB from accessing memory outside the memory map. This
4563 is useful for targets with memory mapped registers or which react
4564 badly to accesses of unmapped address space.
4566 set breakpoint auto-hw
4567 show breakpoint auto-hw
4568 If the target supplies a memory map, for instance via the remote
4569 protocol's "qXfer:memory-map:read" packet, setting this variable
4570 lets GDB use hardware breakpoints automatically for memory regions
4571 where it can not use software breakpoints. This covers both the
4572 "break" command and internal breakpoints used for other commands
4573 including "next" and "finish".
4576 catch exception unhandled
4577 Stop the program execution when Ada exceptions are raised.
4580 Stop the program execution when an Ada assertion failed.
4584 Set an alternate system root for target files. This is a more
4585 general version of "set solib-absolute-prefix", which is now
4586 an alias to "set sysroot".
4589 Provide extended SPU facility status information. This set of
4590 commands is available only when debugging the Cell/B.E. SPU
4593 * New native configurations
4595 OpenBSD/sh sh*-*openbsd*
4598 unset tdesc filename
4600 Use the specified local file as an XML target description, and do
4601 not query the target for its built-in description.
4605 OpenBSD/sh sh*-*-openbsd*
4606 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4607 Toshiba Media Processor mep-elf
4609 * New remote packets
4612 Ignore the specified signals; pass them directly to the debugged program
4613 without stopping other threads or reporting them to GDB.
4615 qXfer:features:read:
4616 Read an XML target description from the target, which describes its
4621 Read or write contents of an spufs file on the target system. These
4622 packets are available only on the Cell/B.E. SPU architecture.
4624 qXfer:libraries:read:
4625 Report the loaded shared libraries. Combined with new "T" packet
4626 response, this packet allows GDB to debug shared libraries on
4627 targets where the operating system manages the list of loaded
4628 libraries (e.g. Windows and SymbianOS).
4632 Support for these obsolete configurations has been removed.
4640 i[34567]86-*-lynxos*
4641 i[34567]86-*-netware*
4642 i[34567]86-*-sco3.2v5*
4643 i[34567]86-*-sco3.2v4*
4645 i[34567]86-*-sysv4.2*
4648 i[34567]86-*-unixware2*
4649 i[34567]86-*-unixware*
4658 * Other removed features
4665 Various m68k-only ROM monitors.
4672 Various Renesas ROM monitors and debugging interfaces for SH and
4677 Support for a Macraigor serial interface to on-chip debugging.
4678 GDB does not directly support the newer parallel or USB
4683 A debug information format. The predecessor to DWARF 2 and
4684 DWARF 3, which are still supported.
4686 Support for the HP aCC compiler on HP-UX/PA-RISC
4688 SOM-encapsulated symbolic debugging information, automatic
4689 invocation of pxdb, and the aCC custom C++ ABI. This does not
4690 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4691 with aCC can still be debugged on an assembly level.
4693 MIPS ".pdr" sections
4695 A MIPS-specific format used to describe stack frame layout
4696 in debugging information.
4700 GDB could work with an older version of Guile to debug
4701 the interpreter and Scheme programs running in it.
4703 set mips stack-arg-size
4704 set mips saved-gpreg-size
4706 Use "set mips abi" to control parameter passing for MIPS.
4708 *** Changes in GDB 6.6
4713 Cell Broadband Engine SPU spu-elf
4715 * GDB can now be configured as a cross-debugger targeting native Windows
4716 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4717 running on a Windows system over TCP/IP to debug Windows programs.
4719 * The GDB remote stub, gdbserver, has been updated to support Windows and
4720 Cygwin debugging. Both single-threaded and multi-threaded programs are
4723 * The "set trust-readonly-sections" command works again. This command was
4724 broken in GDB 6.3, 6.4, and 6.5.
4726 * The "load" command now supports writing to flash memory, if the remote
4727 stub provides the required support.
4729 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4730 longer requires symbolic debug information (e.g. DWARF-2).
4735 unset substitute-path
4736 show substitute-path
4737 Manage a list of substitution rules that GDB uses to rewrite the name
4738 of the directories where the sources are located. This can be useful
4739 for instance when the sources were moved to a different location
4740 between compilation and debugging.
4744 Print each CLI command as it is executed. Each command is prefixed with
4745 a number of `+' symbols representing the nesting depth.
4746 The source command now has a `-v' option to enable the same feature.
4750 The ARM Demon monitor support (RDP protocol, "target rdp").
4752 Kernel Object Display, an embedded debugging feature which only worked with
4753 an obsolete version of Cisco IOS.
4755 The 'set download-write-size' and 'show download-write-size' commands.
4757 * New remote packets
4760 Tell a stub about GDB client features, and request remote target features.
4761 The first feature implemented is PacketSize, which allows the target to
4762 specify the size of packets it can handle - to minimize the number of
4763 packets required and improve performance when connected to a remote
4767 Fetch an OS auxilliary vector from the remote stub. This packet is a
4768 more efficient replacement for qPart:auxv:read.
4770 qXfer:memory-map:read:
4771 Fetch a memory map from the remote stub, including information about
4772 RAM, ROM, and flash memory devices.
4777 Erase and program a flash memory device.
4779 * Removed remote packets
4782 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4783 used it, and only gdbserver implemented it.
4785 *** Changes in GDB 6.5
4789 Renesas M32C/M16C m32c-elf
4791 Morpho Technologies ms1 ms1-elf
4795 init-if-undefined Initialize a convenience variable, but
4796 only if it doesn't already have a value.
4798 The following commands are presently only implemented for native GNU/Linux:
4800 checkpoint Save a snapshot of the program state.
4802 restart <n> Return the program state to a
4803 previously saved state.
4805 info checkpoints List currently saved checkpoints.
4807 delete-checkpoint <n> Delete a previously saved checkpoint.
4809 set|show detach-on-fork Tell gdb whether to detach from a newly
4810 forked process, or to keep debugging it.
4812 info forks List forks of the user program that
4813 are available to be debugged.
4815 fork <n> Switch to debugging one of several
4816 forks of the user program that are
4817 available to be debugged.
4819 delete-fork <n> Delete a fork from the list of forks
4820 that are available to be debugged (and
4821 kill the forked process).
4823 detach-fork <n> Delete a fork from the list of forks
4824 that are available to be debugged (and
4825 allow the process to continue).
4829 Morpho Technologies ms2 ms1-elf
4831 * Improved Windows host support
4833 GDB now builds as a cross debugger hosted on i686-mingw32, including
4834 native console support, and remote communications using either
4835 network sockets or serial ports.
4837 * Improved Modula-2 language support
4839 GDB can now print most types in the Modula-2 syntax. This includes:
4840 basic types, set types, record types, enumerated types, range types,
4841 pointer types and ARRAY types. Procedure var parameters are correctly
4842 printed and hexadecimal addresses and character constants are also
4843 written in the Modula-2 syntax. Best results can be obtained by using
4844 GNU Modula-2 together with the -gdwarf-2 command line option.
4848 The ARM rdi-share module.
4850 The Netware NLM debug server.
4852 *** Changes in GDB 6.4
4854 * New native configurations
4856 OpenBSD/arm arm*-*-openbsd*
4857 OpenBSD/mips64 mips64-*-openbsd*
4861 Morpho Technologies ms1 ms1-elf
4863 * New command line options
4865 --batch-silent As for --batch, but totally silent.
4866 --return-child-result The debugger will exist with the same value
4867 the child (debugged) program exited with.
4868 --eval-command COMMAND, -ex COMMAND
4869 Execute a single GDB CLI command. This may be
4870 specified multiple times and in conjunction
4871 with the --command (-x) option.
4873 * Deprecated commands removed
4875 The following commands, that were deprecated in 2000, have been
4879 set|show arm disassembly-flavor set|show arm disassembler
4880 othernames set arm disassembler
4881 set|show remotedebug set|show debug remote
4882 set|show archdebug set|show debug arch
4883 set|show eventdebug set|show debug event
4886 * New BSD user-level threads support
4888 It is now possible to debug programs using the user-level threads
4889 library on OpenBSD and FreeBSD. Currently supported (target)
4892 FreeBSD/amd64 x86_64-*-freebsd*
4893 FreeBSD/i386 i386-*-freebsd*
4894 OpenBSD/i386 i386-*-openbsd*
4896 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4897 are not yet supported.
4899 * New support for Matsushita MN10300 w/sim added
4900 (Work in progress). mn10300-elf.
4902 * REMOVED configurations and files
4904 VxWorks and the XDR protocol *-*-vxworks
4905 Motorola MCORE mcore-*-*
4906 National Semiconductor NS32000 ns32k-*-*
4908 * New "set print array-indexes" command
4910 After turning this setting "on", GDB prints the index of each element
4911 when displaying arrays. The default is "off" to preserve the previous
4914 * VAX floating point support
4916 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4918 * User-defined command support
4920 In addition to using $arg0..$arg9 for argument passing, it is now possible
4921 to use $argc to determine now many arguments have been passed. See the
4922 section on user-defined commands in the user manual for more information.
4924 *** Changes in GDB 6.3:
4926 * New command line option
4928 GDB now accepts -l followed by a number to set the timeout for remote
4931 * GDB works with GCC -feliminate-dwarf2-dups
4933 GDB now supports a more compact representation of DWARF-2 debug
4934 information using DW_FORM_ref_addr references. These are produced
4935 by GCC with the option -feliminate-dwarf2-dups and also by some
4936 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4937 to use -feliminate-dwarf2-dups.
4939 * Internationalization
4941 When supported by the host system, GDB will be built with
4942 internationalization (libintl). The task of marking up the sources is
4943 continued, we're looking forward to our first translation.
4947 Initial support for debugging programs compiled with the GNAT
4948 implementation of the Ada programming language has been integrated
4949 into GDB. In this release, support is limited to expression evaluation.
4951 * New native configurations
4953 GNU/Linux/m32r m32r-*-linux-gnu
4957 GDB's remote protocol now includes support for the 'p' packet. This
4958 packet is used to fetch individual registers from a remote inferior.
4960 * END-OF-LIFE registers[] compatibility module
4962 GDB's internal register infrastructure has been completely rewritten.
4963 The new infrastructure making possible the implementation of key new
4964 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4967 GDB 6.3 will be the last release to include the the registers[]
4968 compatibility module that allowed out-of-date configurations to
4969 continue to work. This change directly impacts the following
4979 powerpc bdm protocol
4981 Unless there is activity to revive these configurations, they will be
4982 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4984 * OBSOLETE configurations and files
4986 Configurations that have been declared obsolete in this release have
4987 been commented out. Unless there is activity to revive these
4988 configurations, the next release of GDB will have their sources
4989 permanently REMOVED.
4998 *** Changes in GDB 6.2.1:
5000 * MIPS `break main; run' gave an heuristic-fence-post warning
5002 When attempting to run even a simple program, a warning about
5003 heuristic-fence-post being hit would be reported. This problem has
5006 * MIPS IRIX 'long double' crashed GDB
5008 When examining a long double variable, GDB would get a segmentation
5009 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5010 IRIX long double values).
5014 A bug in the VAX stack code was causing problems with the "next"
5015 command. This problem has been fixed.
5017 *** Changes in GDB 6.2:
5019 * Fix for ``many threads''
5021 On GNU/Linux systems that use the NPTL threads library, a program
5022 rapidly creating and deleting threads would confuse GDB leading to the
5025 ptrace: No such process.
5026 thread_db_get_info: cannot get thread info: generic error
5028 This problem has been fixed.
5030 * "-async" and "-noasync" options removed.
5032 Support for the broken "-noasync" option has been removed (it caused
5035 * New ``start'' command.
5037 This command runs the program until the begining of the main procedure.
5039 * New BSD Kernel Data Access Library (libkvm) interface
5041 Using ``target kvm'' it is now possible to debug kernel core dumps and
5042 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5043 platforms. Currently supported (native-only) configurations are:
5045 FreeBSD/amd64 x86_64-*-freebsd*
5046 FreeBSD/i386 i?86-*-freebsd*
5047 NetBSD/i386 i?86-*-netbsd*
5048 NetBSD/m68k m68*-*-netbsd*
5049 NetBSD/sparc sparc-*-netbsd*
5050 OpenBSD/amd64 x86_64-*-openbsd*
5051 OpenBSD/i386 i?86-*-openbsd*
5052 OpenBSD/m68k m68*-openbsd*
5053 OpenBSD/sparc sparc-*-openbsd*
5055 * Signal trampoline code overhauled
5057 Many generic problems with GDB's signal handling code have been fixed.
5058 These include: backtraces through non-contiguous stacks; recognition
5059 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5060 call; backtrace through a signal trampoline; step into and out of
5061 signal handlers; and single-stepping in the signal trampoline.
5063 Please note that kernel bugs are a limiting factor here. These
5064 features have been shown to work on an s390 GNU/Linux system that
5065 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5067 * Cygwin support for DWARF 2 added.
5069 * New native configurations
5071 GNU/Linux/hppa hppa*-*-linux*
5072 OpenBSD/hppa hppa*-*-openbsd*
5073 OpenBSD/m68k m68*-*-openbsd*
5074 OpenBSD/m88k m88*-*-openbsd*
5075 OpenBSD/powerpc powerpc-*-openbsd*
5076 NetBSD/vax vax-*-netbsd*
5077 OpenBSD/vax vax-*-openbsd*
5079 * END-OF-LIFE frame compatibility module
5081 GDB's internal frame infrastructure has been completely rewritten.
5082 The new infrastructure making it possible to support key new features
5083 including DWARF 2 Call Frame Information. To aid in the task of
5084 migrating old configurations to this new infrastructure, a
5085 compatibility module, that allowed old configurations to continue to
5086 work, was also included.
5088 GDB 6.2 will be the last release to include this frame compatibility
5089 module. This change directly impacts the following configurations:
5099 Unless there is activity to revive these configurations, they will be
5100 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5102 * REMOVED configurations and files
5104 Sun 3, running SunOS 3 m68*-*-sunos3*
5105 Sun 3, running SunOS 4 m68*-*-sunos4*
5106 Sun 2, running SunOS 3 m68000-*-sunos3*
5107 Sun 2, running SunOS 4 m68000-*-sunos4*
5108 Motorola 680x0 running LynxOS m68*-*-lynxos*
5109 AT&T 3b1/Unix pc m68*-att-*
5110 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5111 decstation mips-dec-* mips-little-*
5112 riscos mips-*-riscos* mips-*-sysv*
5113 sonymips mips-sony-*
5114 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5116 *** Changes in GDB 6.1.1:
5118 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5120 The TUI (Text-mode User Interface) is now built as part of a default
5121 GDB configuration. It is enabled by either selecting the TUI with the
5122 command line option "-i=tui" or by running the separate "gdbtui"
5123 program. For more information on the TUI, see the manual "Debugging
5126 * Pending breakpoint support (also included in GDB 6.1)
5128 Support has been added to allow you to specify breakpoints in shared
5129 libraries that have not yet been loaded. If a breakpoint location
5130 cannot be found, and the "breakpoint pending" option is set to auto,
5131 GDB queries you if you wish to make the breakpoint pending on a future
5132 shared-library load. If and when GDB resolves the breakpoint symbol,
5133 the pending breakpoint is removed as one or more regular breakpoints
5136 Pending breakpoints are very useful for GCJ Java debugging.
5138 * Fixed ISO-C build problems
5140 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5141 non ISO-C code that stopped them being built using a more strict ISO-C
5142 compiler (e.g., IBM's C compiler).
5144 * Fixed build problem on IRIX 5
5146 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5147 wasn't able to compile compile on an IRIX 5 system.
5149 * Added execute permission to gdb/gdbserver/configure
5151 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5152 permission. This bug would cause configure to fail on a number of
5153 systems (Solaris, IRIX). Ref: server/519.
5155 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5157 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5158 has been updated to use constant array sizes.
5160 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5162 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5163 its generated DWARF Call Frame Info. This encoding was causing GDB to
5164 panic, that panic has been fixed. Ref: gdb/1628.
5166 * Fixed a problem when examining parameters in shared library code.
5168 When examining parameters in optimized shared library code generated
5169 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5170 not available''. GDB now correctly displays the variable's value.
5172 *** Changes in GDB 6.1:
5174 * Removed --with-mmalloc
5176 Support for the mmalloc memory manager has been removed, as it
5177 conflicted with the internal gdb byte cache.
5179 * Changes in AMD64 configurations
5181 The AMD64 target now includes the %cs and %ss registers. As a result
5182 the AMD64 remote protocol has changed; this affects the floating-point
5183 and SSE registers. If you rely on those registers for your debugging,
5184 you should upgrade gdbserver on the remote side.
5186 * Revised SPARC target
5188 The SPARC target has been completely revised, incorporating the
5189 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5190 support for LynxOS and SunOS 4 has been dropped. Calling functions
5191 from within GDB on operating systems with a non-executable stack
5192 (Solaris, OpenBSD) now works.
5196 GDB has a new C++ demangler which does a better job on the mangled
5197 names generated by current versions of g++. It also runs faster, so
5198 with this and other changes gdb should now start faster on large C++
5201 * DWARF 2 Location Expressions
5203 GDB support for location expressions has been extended to support function
5204 arguments and frame bases. Older versions of GDB could crash when they
5207 * C++ nested types and namespaces
5209 GDB's support for nested types and namespaces in C++ has been
5210 improved, especially if you use the DWARF 2 debugging format. (This
5211 is the default for recent versions of GCC on most platforms.)
5212 Specifically, if you have a class "Inner" defined within a class or
5213 namespace "Outer", then GDB realizes that the class's name is
5214 "Outer::Inner", not simply "Inner". This should greatly reduce the
5215 frequency of complaints about not finding RTTI symbols. In addition,
5216 if you are stopped at inside of a function defined within a namespace,
5217 GDB modifies its name lookup accordingly.
5219 * New native configurations
5221 NetBSD/amd64 x86_64-*-netbsd*
5222 OpenBSD/amd64 x86_64-*-openbsd*
5223 OpenBSD/alpha alpha*-*-openbsd*
5224 OpenBSD/sparc sparc-*-openbsd*
5225 OpenBSD/sparc64 sparc64-*-openbsd*
5227 * New debugging protocols
5229 M32R with SDI protocol m32r-*-elf*
5231 * "set prompt-escape-char" command deleted.
5233 The command "set prompt-escape-char" has been deleted. This command,
5234 and its very obscure effet on GDB's prompt, was never documented,
5235 tested, nor mentioned in the NEWS file.
5237 * OBSOLETE configurations and files
5239 Configurations that have been declared obsolete in this release have
5240 been commented out. Unless there is activity to revive these
5241 configurations, the next release of GDB will have their sources
5242 permanently REMOVED.
5244 Sun 3, running SunOS 3 m68*-*-sunos3*
5245 Sun 3, running SunOS 4 m68*-*-sunos4*
5246 Sun 2, running SunOS 3 m68000-*-sunos3*
5247 Sun 2, running SunOS 4 m68000-*-sunos4*
5248 Motorola 680x0 running LynxOS m68*-*-lynxos*
5249 AT&T 3b1/Unix pc m68*-att-*
5250 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5251 decstation mips-dec-* mips-little-*
5252 riscos mips-*-riscos* mips-*-sysv*
5253 sonymips mips-sony-*
5254 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5256 * REMOVED configurations and files
5258 SGI Irix-4.x mips-sgi-irix4 or iris4
5259 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5260 Z8000 simulator z8k-zilog-none or z8ksim
5261 Matsushita MN10200 w/simulator mn10200-*-*
5262 H8/500 simulator h8500-hitachi-hms or h8500hms
5263 HP/PA running BSD hppa*-*-bsd*
5264 HP/PA running OSF/1 hppa*-*-osf*
5265 HP/PA Pro target hppa*-*-pro*
5266 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5267 386BSD i[3456]86-*-bsd*
5268 Sequent family i[3456]86-sequent-sysv4*
5269 i[3456]86-sequent-sysv*
5270 i[3456]86-sequent-bsd*
5271 SPARC running LynxOS sparc-*-lynxos*
5272 SPARC running SunOS 4 sparc-*-sunos4*
5273 Tsqware Sparclet sparclet-*-*
5274 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5276 *** Changes in GDB 6.0:
5280 Support for debugging the Objective-C programming language has been
5281 integrated into GDB.
5283 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5285 DWARF 2's Call Frame Information makes available compiler generated
5286 information that more exactly describes the program's run-time stack.
5287 By using this information, GDB is able to provide more robust stack
5290 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5291 have been updated to use a new backtrace mechanism which includes
5292 DWARF 2 CFI support.
5296 GDB's remote protocol has been extended to include support for hosted
5297 file I/O (where the remote target uses GDB's file system). See GDB's
5298 remote protocol documentation for details.
5300 * All targets using the new architecture framework.
5302 All of GDB's targets have been updated to use the new internal
5303 architecture framework. The way is now open for future GDB releases
5304 to include cross-architecture native debugging support (i386 on amd64,
5307 * GNU/Linux's Thread Local Storage (TLS)
5309 GDB now includes support for for the GNU/Linux implementation of
5310 per-thread variables.
5312 * GNU/Linux's Native POSIX Thread Library (NPTL)
5314 GDB's thread code has been updated to work with either the new
5315 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5317 * Separate debug info.
5319 GDB, in conjunction with BINUTILS, now supports a mechanism for
5320 automatically loading debug information from a separate file. Instead
5321 of shipping full debug and non-debug versions of system libraries,
5322 system integrators can now instead ship just the stripped libraries
5323 and optional debug files.
5325 * DWARF 2 Location Expressions
5327 DWARF 2 Location Expressions allow the compiler to more completely
5328 describe the location of variables (even in optimized code) to the
5331 GDB now includes preliminary support for location expressions (support
5332 for DW_OP_piece is still missing).
5336 A number of long standing bugs that caused GDB to die while starting a
5337 Java application have been fixed. GDB's Java support is now
5338 considered "useable".
5340 * GNU/Linux support for fork, vfork, and exec.
5342 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5343 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5346 * GDB supports logging output to a file
5348 There are two new commands, "set logging" and "show logging", which can be
5349 used to capture GDB's output to a file.
5351 * The meaning of "detach" has changed for gdbserver
5353 The "detach" command will now resume the application, as documented. To
5354 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5357 * d10v, m68hc11 `regs' command deprecated
5359 The `info registers' command has been updated so that it displays the
5360 registers using a format identical to the old `regs' command.
5364 A new command, "maint set profile on/off", has been added. This command can
5365 be used to enable or disable profiling while running GDB, to profile a
5366 session or a set of commands. In addition there is a new configure switch,
5367 "--enable-profiling", which will cause GDB to be compiled with profiling
5368 data, for more informative profiling results.
5370 * Default MI syntax changed to "mi2".
5372 The default MI (machine interface) syntax, enabled by the command line
5373 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5374 "mi1", can be enabled by specifying the option "-i=mi1".
5376 Support for the original "mi0" syntax (included in GDB 5.0) has been
5379 Fix for gdb/192: removed extraneous space when displaying frame level.
5380 Fix for gdb/672: update changelist is now output in mi list format.
5381 Fix for gdb/702: a -var-assign that updates the value now shows up
5382 in a subsequent -var-update.
5384 * New native configurations.
5386 FreeBSD/amd64 x86_64-*-freebsd*
5388 * Multi-arched targets.
5390 HP/PA HPUX11 hppa*-*-hpux*
5391 Renesas M32R/D w/simulator m32r-*-elf*
5393 * OBSOLETE configurations and files
5395 Configurations that have been declared obsolete in this release have
5396 been commented out. Unless there is activity to revive these
5397 configurations, the next release of GDB will have their sources
5398 permanently REMOVED.
5400 Z8000 simulator z8k-zilog-none or z8ksim
5401 Matsushita MN10200 w/simulator mn10200-*-*
5402 H8/500 simulator h8500-hitachi-hms or h8500hms
5403 HP/PA running BSD hppa*-*-bsd*
5404 HP/PA running OSF/1 hppa*-*-osf*
5405 HP/PA Pro target hppa*-*-pro*
5406 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5407 Sequent family i[3456]86-sequent-sysv4*
5408 i[3456]86-sequent-sysv*
5409 i[3456]86-sequent-bsd*
5410 Tsqware Sparclet sparclet-*-*
5411 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5413 * REMOVED configurations and files
5416 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5417 IBM AIX PS/2 i[3456]86-*-aix
5418 i386 running Mach 3.0 i[3456]86-*-mach3*
5419 i386 running Mach i[3456]86-*-mach*
5420 i386 running OSF/1 i[3456]86-*osf1mk*
5421 HP/Apollo 68k Family m68*-apollo*-sysv*,
5423 m68*-hp-bsd*, m68*-hp-hpux*
5424 Argonaut Risc Chip (ARC) arc-*-*
5425 Mitsubishi D30V d30v-*-*
5426 Fujitsu FR30 fr30-*-elf*
5427 OS/9000 i[34]86-*-os9k
5428 I960 with MON960 i960-*-coff
5430 * MIPS $fp behavior changed
5432 The convenience variable $fp, for the MIPS, now consistently returns
5433 the address of the current frame's base. Previously, depending on the
5434 context, $fp could refer to either $sp or the current frame's base
5435 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5436 The GNU Source-Level Debugger''.
5438 *** Changes in GDB 5.3:
5440 * GNU/Linux shared library multi-threaded performance improved.
5442 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5443 `/proc', in preference to `ptrace' for memory reads. This may result
5444 in an improvement in the start-up time of multi-threaded, shared
5445 library applications when run under GDB. One GDB user writes: ``loads
5446 shared libs like mad''.
5448 * ``gdbserver'' now supports multi-threaded applications on some targets
5450 Support for debugging multi-threaded applications which use
5451 the GNU/Linux LinuxThreads package has been added for
5452 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5453 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5455 * GDB now supports C/C++ preprocessor macros.
5457 GDB now expands preprocessor macro invocations in C/C++ expressions,
5458 and provides various commands for showing macro definitions and how
5461 The new command `macro expand EXPRESSION' expands any macro
5462 invocations in expression, and shows the result.
5464 The new command `show macro MACRO-NAME' shows the definition of the
5465 macro named MACRO-NAME, and where it was defined.
5467 Most compilers don't include information about macros in the debugging
5468 information by default. In GCC 3.1, for example, you need to compile
5469 your program with the options `-gdwarf-2 -g3'. If the macro
5470 information is present in the executable, GDB will read it.
5472 * Multi-arched targets.
5474 DEC Alpha (partial) alpha*-*-*
5475 DEC VAX (partial) vax-*-*
5477 National Semiconductor NS32000 (partial) ns32k-*-*
5478 Motorola 68000 (partial) m68k-*-*
5479 Motorola MCORE mcore-*-*
5483 Fujitsu FRV architecture added by Red Hat frv*-*-*
5486 * New native configurations
5488 Alpha NetBSD alpha*-*-netbsd*
5489 SH NetBSD sh*-*-netbsdelf*
5490 MIPS NetBSD mips*-*-netbsd*
5491 UltraSPARC NetBSD sparc64-*-netbsd*
5493 * OBSOLETE configurations and files
5495 Configurations that have been declared obsolete in this release have
5496 been commented out. Unless there is activity to revive these
5497 configurations, the next release of GDB will have their sources
5498 permanently REMOVED.
5500 Mitsubishi D30V d30v-*-*
5501 OS/9000 i[34]86-*-os9k
5502 IBM AIX PS/2 i[3456]86-*-aix
5503 Fujitsu FR30 fr30-*-elf*
5504 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5505 Argonaut Risc Chip (ARC) arc-*-*
5506 i386 running Mach 3.0 i[3456]86-*-mach3*
5507 i386 running Mach i[3456]86-*-mach*
5508 i386 running OSF/1 i[3456]86-*osf1mk*
5509 HP/Apollo 68k Family m68*-apollo*-sysv*,
5511 m68*-hp-bsd*, m68*-hp-hpux*
5512 I960 with MON960 i960-*-coff
5514 * OBSOLETE languages
5516 CHILL, a Pascal like language used by telecommunications companies.
5518 * REMOVED configurations and files
5520 AMD 29k family via UDI a29k-amd-udi, udi29k
5521 A29K VxWorks a29k-*-vxworks
5522 AMD 29000 embedded, using EBMON a29k-none-none
5523 AMD 29000 embedded with COFF a29k-none-coff
5524 AMD 29000 embedded with a.out a29k-none-aout
5526 testsuite/gdb.hp/gdb.threads-hp/ directory
5528 * New command "set max-user-call-depth <nnn>"
5530 This command allows the user to limit the call depth of user-defined
5531 commands. The default is 1024.
5533 * Changes in FreeBSD/i386 native debugging.
5535 Support for the "generate-core-file" has been added.
5537 * New commands "dump", "append", and "restore".
5539 These commands allow data to be copied from target memory
5540 to a bfd-format or binary file (dump and append), and back
5541 from a file into memory (restore).
5543 * Improved "next/step" support on multi-processor Alpha Tru64.
5545 The previous single-step mechanism could cause unpredictable problems,
5546 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5547 of a software single-step mechanism prevents this.
5549 *** Changes in GDB 5.2.1:
5557 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5558 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5559 Fix, by Joel Brobecker imported from mainline.
5561 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5562 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5563 Fix, by Fred Fish, imported from mainline.
5565 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5566 Surprisingly enough, it works now.
5567 By Michal Ludvig, imported from mainline.
5569 i386 hardware watchpoint support:
5570 avoid misses on second run for some targets.
5571 By Pierre Muller, imported from mainline.
5573 *** Changes in GDB 5.2:
5575 * New command "set trust-readonly-sections on[off]".
5577 This command is a hint that tells gdb that read-only sections
5578 really are read-only (ie. that their contents will not change).
5579 In this mode, gdb will go to the object file rather than the
5580 target to read memory from read-only sections (such as ".text").
5581 This can be a significant performance improvement on some
5582 (notably embedded) targets.
5584 * New command "generate-core-file" (or "gcore").
5586 This new gdb command allows the user to drop a core file of the child
5587 process state at any time. So far it's been implemented only for
5588 GNU/Linux and Solaris, but should be relatively easily ported to other
5589 hosts. Argument is core file name (defaults to core.<pid>).
5591 * New command line option
5593 GDB now accepts --pid or -p followed by a process id.
5595 * Change in command line behavior -- corefiles vs. process ids.
5597 There is a subtle behavior in the way in which GDB handles
5598 command line arguments. The first non-flag argument is always
5599 a program to debug, but the second non-flag argument may either
5600 be a corefile or a process id. Previously, GDB would attempt to
5601 open the second argument as a corefile, and if that failed, would
5602 issue a superfluous error message and then attempt to attach it as
5603 a process. Now, if the second argument begins with a non-digit,
5604 it will be treated as a corefile. If it begins with a digit,
5605 GDB will attempt to attach it as a process, and if no such process
5606 is found, will then attempt to open it as a corefile.
5608 * Changes in ARM configurations.
5610 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5611 configuration is fully multi-arch.
5613 * New native configurations
5615 ARM NetBSD arm*-*-netbsd*
5616 x86 OpenBSD i[3456]86-*-openbsd*
5617 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5618 Sparc64 running FreeBSD sparc64-*-freebsd*
5622 Sanyo XStormy16 xstormy16-elf
5624 * OBSOLETE configurations and files
5626 Configurations that have been declared obsolete in this release have
5627 been commented out. Unless there is activity to revive these
5628 configurations, the next release of GDB will have their sources
5629 permanently REMOVED.
5631 AMD 29k family via UDI a29k-amd-udi, udi29k
5632 A29K VxWorks a29k-*-vxworks
5633 AMD 29000 embedded, using EBMON a29k-none-none
5634 AMD 29000 embedded with COFF a29k-none-coff
5635 AMD 29000 embedded with a.out a29k-none-aout
5637 testsuite/gdb.hp/gdb.threads-hp/ directory
5639 * REMOVED configurations and files
5641 TI TMS320C80 tic80-*-*
5643 PowerPC Solaris powerpcle-*-solaris*
5644 PowerPC Windows NT powerpcle-*-cygwin32
5645 PowerPC Netware powerpc-*-netware*
5646 Harris/CXUX m88k m88*-harris-cxux*
5647 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5648 ns32k-utek-sysv* ns32k-utek-*
5649 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5650 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5651 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5652 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5653 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5655 * Changes to command line processing
5657 The new `--args' feature can be used to specify command-line arguments
5658 for the inferior from gdb's command line.
5660 * Changes to key bindings
5662 There is a new `operate-and-get-next' function bound to `C-o'.
5664 *** Changes in GDB 5.1.1
5666 Fix compile problem on DJGPP.
5668 Fix a problem with floating-point registers on the i386 being
5671 Fix to stop GDB crashing on .debug_str debug info.
5673 Numerous documentation fixes.
5675 Numerous testsuite fixes.
5677 *** Changes in GDB 5.1:
5679 * New native configurations
5681 Alpha FreeBSD alpha*-*-freebsd*
5682 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5683 MIPS GNU/Linux mips*-*-linux*
5684 MIPS SGI Irix 6.x mips*-sgi-irix6*
5685 ia64 AIX ia64-*-aix*
5686 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5690 Motorola 68HC11 and 68HC12 m68hc11-elf
5692 UltraSparc running GNU/Linux sparc64-*-linux*
5694 * OBSOLETE configurations and files
5696 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5697 Harris/CXUX m88k m88*-harris-cxux*
5698 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5699 ns32k-utek-sysv* ns32k-utek-*
5700 TI TMS320C80 tic80-*-*
5702 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5703 PowerPC Solaris powerpcle-*-solaris*
5704 PowerPC Windows NT powerpcle-*-cygwin32
5705 PowerPC Netware powerpc-*-netware*
5706 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5707 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5708 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5709 Apple Macintosh (MPW) host N/A
5711 stuff.c (Program to stuff files into a specially prepared space in kdb)
5712 kdb-start.c (Main loop for the standalone kernel debugger)
5714 Configurations that have been declared obsolete in this release have
5715 been commented out. Unless there is activity to revive these
5716 configurations, the next release of GDB will have their sources
5717 permanently REMOVED.
5719 * REMOVED configurations and files
5721 Altos 3068 m68*-altos-*
5722 Convex c1-*-*, c2-*-*
5724 ARM RISCix arm-*-* (as host)
5728 * GDB has been converted to ISO C.
5730 GDB's source code has been converted to ISO C. In particular, the
5731 sources are fully protoized, and rely on standard headers being
5736 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5738 * The MI enabled by default.
5740 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5741 revised and enabled by default. Packages which use GDB as a debugging
5742 engine behind a UI or another front end are encouraged to switch to
5743 using the GDB/MI interface, instead of the old annotations interface
5744 which is now deprecated.
5746 * Support for debugging Pascal programs.
5748 GDB now includes support for debugging Pascal programs. The following
5749 main features are supported:
5751 - Pascal-specific data types such as sets;
5753 - automatic recognition of Pascal sources based on file-name
5756 - Pascal-style display of data types, variables, and functions;
5758 - a Pascal expression parser.
5760 However, some important features are not yet supported.
5762 - Pascal string operations are not supported at all;
5764 - there are some problems with boolean types;
5766 - Pascal type hexadecimal constants are not supported
5767 because they conflict with the internal variables format;
5769 - support for Pascal objects and classes is not full yet;
5771 - unlike Pascal, GDB is case-sensitive for symbol names.
5773 * Changes in completion.
5775 Commands such as `shell', `run' and `set args', which pass arguments
5776 to inferior programs, now complete on file names, similar to what
5777 users expect at the shell prompt.
5779 Commands which accept locations, such as `disassemble', `print',
5780 `breakpoint', `until', etc. now complete on filenames as well as
5781 program symbols. Thus, if you type "break foob TAB", and the source
5782 files linked into the programs include `foobar.c', that file name will
5783 be one of the candidates for completion. However, file names are not
5784 considered for completion after you typed a colon that delimits a file
5785 name from a name of a function in that file, as in "break foo.c:bar".
5787 `set demangle-style' completes on available demangling styles.
5789 * New platform-independent commands:
5791 It is now possible to define a post-hook for a command as well as a
5792 hook that runs before the command. For more details, see the
5793 documentation of `hookpost' in the GDB manual.
5795 * Changes in GNU/Linux native debugging.
5797 Support for debugging multi-threaded programs has been completely
5798 revised for all platforms except m68k and sparc. You can now debug as
5799 many threads as your system allows you to have.
5801 Attach/detach is supported for multi-threaded programs.
5803 Support for SSE registers was added for x86. This doesn't work for
5804 multi-threaded programs though.
5806 * Changes in MIPS configurations.
5808 Multi-arch support is enabled for all MIPS configurations.
5810 GDB can now be built as native debugger on SGI Irix 6.x systems for
5811 debugging n32 executables. (Debugging 64-bit executables is not yet
5814 * Unified support for hardware watchpoints in all x86 configurations.
5816 Most (if not all) native x86 configurations support hardware-assisted
5817 breakpoints and watchpoints in a unified manner. This support
5818 implements debug register sharing between watchpoints, which allows to
5819 put a virtually infinite number of watchpoints on the same address,
5820 and also supports watching regions up to 16 bytes with several debug
5823 The new maintenance command `maintenance show-debug-regs' toggles
5824 debugging print-outs in functions that insert, remove, and test
5825 watchpoints and hardware breakpoints.
5827 * Changes in the DJGPP native configuration.
5829 New command ``info dos sysinfo'' displays assorted information about
5830 the CPU, OS, memory, and DPMI server.
5832 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5833 display information about segment descriptors stored in GDT, LDT, and
5836 New commands ``info dos pde'' and ``info dos pte'' display entries
5837 from Page Directory and Page Tables (for now works with CWSDPMI only).
5838 New command ``info dos address-pte'' displays the Page Table entry for
5839 a given linear address.
5841 GDB can now pass command lines longer than 126 characters to the
5842 program being debugged (requires an update to the libdbg.a library
5843 which is part of the DJGPP development kit).
5845 DWARF2 debug info is now supported.
5847 It is now possible to `step' and `next' through calls to `longjmp'.
5849 * Changes in documentation.
5851 All GDB documentation was converted to GFDL, the GNU Free
5852 Documentation License.
5854 Tracepoints-related commands are now fully documented in the GDB
5857 TUI, the Text-mode User Interface, is now documented in the manual.
5859 Tracepoints-related commands are now fully documented in the GDB
5862 The "GDB Internals" manual now has an index. It also includes
5863 documentation of `ui_out' functions, GDB coding standards, x86
5864 hardware watchpoints, and memory region attributes.
5866 * GDB's version number moved to ``version.in''
5868 The Makefile variable VERSION has been replaced by the file
5869 ``version.in''. People creating GDB distributions should update the
5870 contents of this file.
5874 GUD support is now a standard part of the EMACS distribution.
5876 *** Changes in GDB 5.0:
5878 * Improved support for debugging FP programs on x86 targets
5880 Unified and much-improved support for debugging floating-point
5881 programs on all x86 targets. In particular, ``info float'' now
5882 displays the FP registers in the same format on all x86 targets, with
5883 greater level of detail.
5885 * Improvements and bugfixes in hardware-assisted watchpoints
5887 It is now possible to watch array elements, struct members, and
5888 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5889 on x86 targets no longer erroneously trigger when the address is
5892 * Improvements in the native DJGPP version of GDB
5894 The distribution now includes all the scripts and auxiliary files
5895 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5896 machines ``out of the box''.
5898 The DJGPP version can now debug programs that use signals. It is
5899 possible to catch signals that happened in the debuggee, deliver
5900 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5901 would kill the program being debugged.) Programs that hook hardware
5902 interrupts (keyboard, timer, etc.) can also be debugged.
5904 It is now possible to debug DJGPP programs that redirect their
5905 standard handles or switch them to raw (as opposed to cooked) mode, or
5906 even close them. The command ``run < foo > bar'' works as expected,
5907 and ``info terminal'' reports useful information about the debuggee's
5908 terminal, including raw/cooked mode, redirection, etc.
5910 The DJGPP version now uses termios functions for console I/O, which
5911 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5914 DOS-style file names with drive letters are now fully supported by
5917 It is now possible to debug DJGPP programs that switch their working
5918 directory. It is also possible to rerun the debuggee any number of
5919 times without restarting GDB; thus, you can use the same setup,
5920 breakpoints, etc. for many debugging sessions.
5922 * New native configurations
5924 ARM GNU/Linux arm*-*-linux*
5925 PowerPC GNU/Linux powerpc-*-linux*
5929 Motorola MCore mcore-*-*
5930 x86 VxWorks i[3456]86-*-vxworks*
5931 PowerPC VxWorks powerpc-*-vxworks*
5932 TI TMS320C80 tic80-*-*
5934 * OBSOLETE configurations
5936 Altos 3068 m68*-altos-*
5937 Convex c1-*-*, c2-*-*
5939 ARM RISCix arm-*-* (as host)
5942 Configurations that have been declared obsolete will be commented out,
5943 but the code will be left in place. If there is no activity to revive
5944 these configurations before the next release of GDB, the sources will
5945 be permanently REMOVED.
5947 * Gould support removed
5949 Support for the Gould PowerNode and NP1 has been removed.
5951 * New features for SVR4
5953 On SVR4 native platforms (such as Solaris), if you attach to a process
5954 without first loading a symbol file, GDB will now attempt to locate and
5955 load symbols from the running process's executable file.
5957 * Many C++ enhancements
5959 C++ support has been greatly improved. Overload resolution now works properly
5960 in almost all cases. RTTI support is on the way.
5962 * Remote targets can connect to a sub-program
5964 A popen(3) style serial-device has been added. This device starts a
5965 sub-process (such as a stand-alone simulator) and then communicates
5966 with that. The sub-program to run is specified using the syntax
5967 ``|<program> <args>'' vis:
5969 (gdb) set remotedebug 1
5970 (gdb) target extended-remote |mn10300-elf-sim program-args
5972 * MIPS 64 remote protocol
5974 A long standing bug in the mips64 remote protocol where by GDB
5975 expected certain 32 bit registers (ex SR) to be transfered as 32
5976 instead of 64 bits has been fixed.
5978 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5979 added to provide backward compatibility with older versions of GDB.
5981 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5983 The command ``set remotebinarydownload'' command has been replaced by
5984 ``set remote X-packet''. Other commands in ``set remote'' family
5985 include ``set remote P-packet''.
5987 * Breakpoint commands accept ranges.
5989 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5990 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5991 ``tracepoint passcount'' also accepts a range of tracepoints.
5993 * ``apropos'' command added.
5995 The ``apropos'' command searches through command names and
5996 documentation strings, printing out matches, making it much easier to
5997 try to find a command that does what you are looking for.
6001 A new machine oriented interface (MI) has been added to GDB. This
6002 interface is designed for debug environments running GDB as a separate
6003 process. This is part of the long term libGDB project. See the
6004 "GDB/MI" chapter of the GDB manual for further information. It can be
6005 enabled by configuring with:
6007 .../configure --enable-gdbmi
6009 *** Changes in GDB-4.18:
6011 * New native configurations
6013 HP-UX 10.20 hppa*-*-hpux10.20
6014 HP-UX 11.x hppa*-*-hpux11.0*
6015 M68K GNU/Linux m68*-*-linux*
6019 Fujitsu FR30 fr30-*-elf*
6020 Intel StrongARM strongarm-*-*
6021 Mitsubishi D30V d30v-*-*
6023 * OBSOLETE configurations
6025 Gould PowerNode, NP1 np1-*-*, pn-*-*
6027 Configurations that have been declared obsolete will be commented out,
6028 but the code will be left in place. If there is no activity to revive
6029 these configurations before the next release of GDB, the sources will
6030 be permanently REMOVED.
6034 As a compatibility experiment, GDB's source files buildsym.h and
6035 buildsym.c have been converted to pure standard C, no longer
6036 containing any K&R compatibility code. We believe that all systems in
6037 use today either come with a standard C compiler, or have a GCC port
6038 available. If this is not true, please report the affected
6039 configuration to bug-gdb@gnu.org immediately. See the README file for
6040 information about getting a standard C compiler if you don't have one
6045 GDB now uses readline 2.2.
6047 * set extension-language
6049 You can now control the mapping between filename extensions and source
6050 languages by using the `set extension-language' command. For instance,
6051 you can ask GDB to treat .c files as C++ by saying
6052 set extension-language .c c++
6053 The command `info extensions' lists all of the recognized extensions
6054 and their associated languages.
6056 * Setting processor type for PowerPC and RS/6000
6058 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6059 you can use the `set processor' command to specify what variant of the
6060 PowerPC family you are debugging. The command
6064 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6065 following PowerPC and RS6000 variants:
6067 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6068 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6070 403GC IBM PowerPC 403GC
6071 505 Motorola PowerPC 505
6072 860 Motorola PowerPC 860 or 850
6073 601 Motorola PowerPC 601
6074 602 Motorola PowerPC 602
6075 603 Motorola/IBM PowerPC 603 or 603e
6076 604 Motorola PowerPC 604 or 604e
6077 750 Motorola/IBM PowerPC 750 or 750
6079 At the moment, this command just tells GDB what to name the
6080 special-purpose processor registers. Since almost all the affected
6081 registers are inaccessible to user-level programs, this command is
6082 only useful for remote debugging in its present form.
6086 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6087 more extensive support for HP-UX. Added features include shared
6088 library support, kernel threads and hardware watchpoints for 11.00,
6089 support for HP's ANSI C and C++ compilers, and a compatibility mode
6090 for xdb and dbx commands.
6094 HP's donation includes the new concept of catchpoints, which is a
6095 generalization of the old catch command. On HP-UX, it is now possible
6096 to catch exec, fork, and vfork, as well as library loading.
6098 This means that the existing catch command has changed; its first
6099 argument now specifies the type of catch to be set up. See the
6100 output of "help catch" for a list of catchpoint types.
6102 * Debugging across forks
6104 On HP-UX, you can choose which process to debug when a fork() happens
6109 HP has donated a curses-based terminal user interface (TUI). To get
6110 it, build with --enable-tui. Although this can be enabled for any
6111 configuration, at present it only works for native HP debugging.
6113 * GDB remote protocol additions
6115 A new protocol packet 'X' that writes binary data is now available.
6116 Default behavior is to try 'X', then drop back to 'M' if the stub
6117 fails to respond. The settable variable `remotebinarydownload'
6118 allows explicit control over the use of 'X'.
6120 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6121 full 64-bit address. The command
6123 set remoteaddresssize 32
6125 can be used to revert to the old behaviour. For existing remote stubs
6126 the change should not be noticed, as the additional address information
6129 In order to assist in debugging stubs, you may use the maintenance
6130 command `packet' to send any text string to the stub. For instance,
6132 maint packet heythere
6134 sends the packet "$heythere#<checksum>". Note that it is very easy to
6135 disrupt a debugging session by sending the wrong packet at the wrong
6138 The compare-sections command allows you to compare section data on the
6139 target to what is in the executable file without uploading or
6140 downloading, by comparing CRC checksums.
6142 * Tracing can collect general expressions
6144 You may now collect general expressions at tracepoints. This requires
6145 further additions to the target-side stub; see tracepoint.c and
6146 doc/agentexpr.texi for further details.
6148 * mask-address variable for Mips
6150 For Mips targets, you may control the zeroing of the upper 32 bits of
6151 a 64-bit address by entering `set mask-address on'. This is mainly
6152 of interest to users of embedded R4xxx and R5xxx processors.
6154 * Higher serial baud rates
6156 GDB's serial code now allows you to specify baud rates 57600, 115200,
6157 230400, and 460800 baud. (Note that your host system may not be able
6158 to achieve all of these rates.)
6162 The i960 configuration now includes an initial implementation of a
6163 builtin simulator, contributed by Jim Wilson.
6166 *** Changes in GDB-4.17:
6168 * New native configurations
6170 Alpha GNU/Linux alpha*-*-linux*
6171 Unixware 2.x i[3456]86-unixware2*
6172 Irix 6.x mips*-sgi-irix6*
6173 PowerPC GNU/Linux powerpc-*-linux*
6174 PowerPC Solaris powerpcle-*-solaris*
6175 Sparc GNU/Linux sparc-*-linux*
6176 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6180 Argonaut Risc Chip (ARC) arc-*-*
6181 Hitachi H8/300S h8300*-*-*
6182 Matsushita MN10200 w/simulator mn10200-*-*
6183 Matsushita MN10300 w/simulator mn10300-*-*
6184 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6185 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6186 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6187 Mitsubishi D10V w/simulator d10v-*-*
6188 Mitsubishi M32R/D w/simulator m32r-*-elf*
6189 Tsqware Sparclet sparclet-*-*
6190 NEC V850 w/simulator v850-*-*
6192 * New debugging protocols
6194 ARM with RDI protocol arm*-*-*
6195 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6196 DDB and LSI variants of PMON protocol mips*-*-*
6197 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6198 PowerPC with SDS protocol powerpc{,le}-*-eabi
6199 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6203 All configurations can now understand and use the DWARF 2 debugging
6204 format. The choice is automatic, if the symbol file contains DWARF 2
6209 GDB now includes basic Java language support. This support is
6210 only useful with Java compilers that produce native machine code.
6212 * solib-absolute-prefix and solib-search-path
6214 For SunOS and SVR4 shared libraries, you may now set the prefix for
6215 loading absolute shared library symbol files, and the search path for
6216 locating non-absolute shared library symbol files.
6218 * Live range splitting
6220 GDB can now effectively debug code for which GCC has performed live
6221 range splitting as part of its optimization. See gdb/doc/LRS for
6222 more details on the expected format of the stabs information.
6226 GDB's support for the GNU Hurd, including thread debugging, has been
6227 updated to work with current versions of the Hurd.
6231 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6232 instruction set. ARM GDB automatically detects when Thumb
6233 instructions are in use, and adjusts disassembly and backtracing
6238 GDB's MIPS target configurations now handle the MIP16 16-bit
6243 GDB now includes support for overlays; if an executable has been
6244 linked such that multiple sections are based at the same address, GDB
6245 will decide which section to use for symbolic info. You can choose to
6246 control the decision manually, using overlay commands, or implement
6247 additional target-side support and use "overlay load-target" to bring
6248 in the overlay mapping. Do "help overlay" for more detail.
6252 The command "info symbol <address>" displays information about
6253 the symbol at the specified address.
6257 The standard remote protocol now includes an extension that allows
6258 asynchronous collection and display of trace data. This requires
6259 extensive support in the target-side debugging stub. Tracing mode
6260 includes a new interaction mode in GDB and new commands: see the
6261 file tracepoint.c for more details.
6265 Configurations for embedded MIPS now include a simulator contributed
6266 by Cygnus Solutions. The simulator supports the instruction sets
6267 of most MIPS variants.
6271 Sparc configurations may now include the ERC32 simulator contributed
6272 by the European Space Agency. The simulator is not built into
6273 Sparc targets by default; configure with --enable-sim to include it.
6277 For target configurations that may include multiple variants of a
6278 basic architecture (such as MIPS and SH), you may now set the
6279 architecture explicitly. "set arch" sets, "info arch" lists
6280 the possible architectures.
6282 *** Changes in GDB-4.16:
6284 * New native configurations
6286 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6287 M68K NetBSD m68k-*-netbsd*
6288 PowerPC AIX 4.x powerpc-*-aix*
6289 PowerPC MacOS powerpc-*-macos*
6290 PowerPC Windows NT powerpcle-*-cygwin32
6291 RS/6000 AIX 4.x rs6000-*-aix4*
6295 ARM with RDP protocol arm-*-*
6296 I960 with MON960 i960-*-coff
6297 MIPS VxWorks mips*-*-vxworks*
6298 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6299 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6301 Matra Sparclet sparclet-*-*
6305 The powerpc-eabi configuration now includes the PSIM simulator,
6306 contributed by Andrew Cagney, with assistance from Mike Meissner.
6307 PSIM is a very elaborate model of the PowerPC, including not only
6308 basic instruction set execution, but also details of execution unit
6309 performance and I/O hardware. See sim/ppc/README for more details.
6313 GDB now works with Solaris 2.5.
6315 * Windows 95/NT native
6317 GDB will now work as a native debugger on Windows 95 and Windows NT.
6318 To build it from source, you must use the "gnu-win32" environment,
6319 which uses a DLL to emulate enough of Unix to run the GNU tools.
6320 Further information, binaries, and sources are available at
6321 ftp.cygnus.com, under pub/gnu-win32.
6323 * dont-repeat command
6325 If a user-defined command includes the command `dont-repeat', then the
6326 command will not be repeated if the user just types return. This is
6327 useful if the command is time-consuming to run, so that accidental
6328 extra keystrokes don't run the same command many times.
6330 * Send break instead of ^C
6332 The standard remote protocol now includes an option to send a break
6333 rather than a ^C to the target in order to interrupt it. By default,
6334 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6336 * Remote protocol timeout
6338 The standard remote protocol includes a new variable `remotetimeout'
6339 that allows you to set the number of seconds before GDB gives up trying
6340 to read from the target. The default value is 2.
6342 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6344 By default GDB will automatically keep track of objects as they are
6345 loaded and unloaded by the dynamic linker. By using the command `set
6346 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6347 when shared library events occur, thus allowing you to set breakpoints
6348 in shared libraries which are explicitly loaded by the inferior.
6350 Note this feature does not work on hpux8. On hpux9 you must link
6351 /usr/lib/end.o into your program. This feature should work
6352 automatically on hpux10.
6354 * Irix 5.x hardware watchpoint support
6356 Irix 5 configurations now support the use of hardware watchpoints.
6358 * Mips protocol "SYN garbage limit"
6360 When debugging a Mips target using the `target mips' protocol, you
6361 may set the number of characters that GDB will ignore by setting
6362 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6363 every character. The default value is 1050.
6365 * Recording and replaying remote debug sessions
6367 If you set `remotelogfile' to the name of a file, gdb will write to it
6368 a recording of a remote debug session. This recording may then be
6369 replayed back to gdb using "gdbreplay". See gdbserver/README for
6370 details. This is useful when you have a problem with GDB while doing
6371 remote debugging; you can make a recording of the session and send it
6372 to someone else, who can then recreate the problem.
6374 * Speedups for remote debugging
6376 GDB includes speedups for downloading and stepping MIPS systems using
6377 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6378 and more efficient S-record downloading.
6380 * Memory use reductions and statistics collection
6382 GDB now uses less memory and reports statistics about memory usage.
6383 Try the `maint print statistics' command, for example.
6385 *** Changes in GDB-4.15:
6387 * Psymtabs for XCOFF
6389 The symbol reader for AIX GDB now uses partial symbol tables. This
6390 can greatly improve startup time, especially for large executables.
6392 * Remote targets use caching
6394 Remote targets now use a data cache to speed up communication with the
6395 remote side. The data cache could lead to incorrect results because
6396 it doesn't know about volatile variables, thus making it impossible to
6397 debug targets which use memory mapped I/O devices. `set remotecache
6398 off' turns the the data cache off.
6400 * Remote targets may have threads
6402 The standard remote protocol now includes support for multiple threads
6403 in the target system, using new protocol commands 'H' and 'T'. See
6404 gdb/remote.c for details.
6408 If GDB is configured with `--enable-netrom', then it will include
6409 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6410 acts as though it is a bank of ROM on the target board, but you can
6411 write into it over the network. GDB's support consists only of
6412 support for fast loading into the emulated ROM; to debug, you must use
6413 another protocol, such as standard remote protocol. The usual
6414 sequence is something like
6416 target nrom <netrom-hostname>
6418 target remote <netrom-hostname>:1235
6422 GDB now includes support for the Apple Macintosh, as a host only. It
6423 may be run as either an MPW tool or as a standalone application, and
6424 it can debug through the serial port. All the usual GDB commands are
6425 available, but to the target command, you must supply "serial" as the
6426 device type instead of "/dev/ttyXX". See mpw-README in the main
6427 directory for more information on how to build. The MPW configuration
6428 scripts */mpw-config.in support only a few targets, and only the
6429 mips-idt-ecoff target has been tested.
6433 GDB configuration now uses autoconf. This is not user-visible,
6434 but does simplify configuration and building.
6438 GDB now supports hpux10.
6440 *** Changes in GDB-4.14:
6442 * New native configurations
6444 x86 FreeBSD i[345]86-*-freebsd
6445 x86 NetBSD i[345]86-*-netbsd
6446 NS32k NetBSD ns32k-*-netbsd
6447 Sparc NetBSD sparc-*-netbsd
6451 A29K VxWorks a29k-*-vxworks
6452 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6453 CPU32 EST-300 emulator m68*-*-est*
6454 PowerPC ELF powerpc-*-elf
6457 * Alpha OSF/1 support for procfs
6459 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6460 possible to attach to running processes. As the mounting of the /proc
6461 filesystem is optional on the Alpha, GDB automatically determines
6462 the availability of /proc during startup. This can lead to problems
6463 if /proc is unmounted after GDB has been started.
6465 * Arguments to user-defined commands
6467 User commands may accept up to 10 arguments separated by whitespace.
6468 Arguments are accessed within the user command via $arg0..$arg9. A
6471 print $arg0 + $arg1 + $arg2
6473 To execute the command use:
6476 Defines the command "adder" which prints the sum of its three arguments.
6477 Note the arguments are text substitutions, so they may reference variables,
6478 use complex expressions, or even perform inferior function calls.
6480 * New `if' and `while' commands
6482 This makes it possible to write more sophisticated user-defined
6483 commands. Both commands take a single argument, which is the
6484 expression to evaluate, and must be followed by the commands to
6485 execute, one per line, if the expression is nonzero, the list being
6486 terminated by the word `end'. The `if' command list may include an
6487 `else' word, which causes the following commands to be executed only
6488 if the expression is zero.
6490 * Fortran source language mode
6492 GDB now includes partial support for Fortran 77. It will recognize
6493 Fortran programs and can evaluate a subset of Fortran expressions, but
6494 variables and functions may not be handled correctly. GDB will work
6495 with G77, but does not yet know much about symbols emitted by other
6498 * Better HPUX support
6500 Most debugging facilities now work on dynamic executables for HPPAs
6501 running hpux9 or later. You can attach to running dynamically linked
6502 processes, but by default the dynamic libraries will be read-only, so
6503 for instance you won't be able to put breakpoints in them. To change
6504 that behavior do the following before running the program:
6510 This will cause the libraries to be mapped private and read-write.
6511 To revert to the normal behavior, do this:
6517 You cannot set breakpoints or examine data in the library until after
6518 the library is loaded if the function/data symbols do not have
6521 GDB can now also read debug symbols produced by the HP C compiler on
6522 HPPAs (sorry, no C++, Fortran or 68k support).
6524 * Target byte order now dynamically selectable
6526 You can choose which byte order to use with a target system, via the
6527 commands "set endian big" and "set endian little", and you can see the
6528 current setting by using "show endian". You can also give the command
6529 "set endian auto", in which case GDB will use the byte order
6530 associated with the executable. Currently, only embedded MIPS
6531 configurations support dynamic selection of target byte order.
6533 * New DOS host serial code
6535 This version uses DPMI interrupts to handle buffered I/O, so you
6536 no longer need to run asynctsr when debugging boards connected to
6539 *** Changes in GDB-4.13:
6541 * New "complete" command
6543 This lists all the possible completions for the rest of the line, if it
6544 were to be given as a command itself. This is intended for use by emacs.
6546 * Trailing space optional in prompt
6548 "set prompt" no longer adds a space for you after the prompt you set. This
6549 allows you to set a prompt which ends in a space or one that does not.
6551 * Breakpoint hit counts
6553 "info break" now displays a count of the number of times the breakpoint
6554 has been hit. This is especially useful in conjunction with "ignore"; you
6555 can ignore a large number of breakpoint hits, look at the breakpoint info
6556 to see how many times the breakpoint was hit, then run again, ignoring one
6557 less than that number, and this will get you quickly to the last hit of
6560 * Ability to stop printing at NULL character
6562 "set print null-stop" will cause GDB to stop printing the characters of
6563 an array when the first NULL is encountered. This is useful when large
6564 arrays actually contain only short strings.
6566 * Shared library breakpoints
6568 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6569 breakpoints in shared libraries before the executable is run.
6571 * Hardware watchpoints
6573 There is a new hardware breakpoint for the watch command for sparclite
6574 targets. See gdb/sparclite/hw_breakpoint.note.
6576 Hardware watchpoints are also now supported under GNU/Linux.
6580 Annotations have been added. These are for use with graphical interfaces,
6581 and are still experimental. Currently only gdba.el uses these.
6583 * Improved Irix 5 support
6585 GDB now works properly with Irix 5.2.
6587 * Improved HPPA support
6589 GDB now works properly with the latest GCC and GAS.
6591 * New native configurations
6593 Sequent PTX4 i[34]86-sequent-ptx4
6594 HPPA running OSF/1 hppa*-*-osf*
6595 Atari TT running SVR4 m68*-*-sysv4*
6596 RS/6000 LynxOS rs6000-*-lynxos*
6600 OS/9000 i[34]86-*-os9k
6601 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6604 * Hitachi SH7000 and E7000-PC ICE support
6606 There is now support for communicating with the Hitachi E7000-PC ICE.
6607 This is available automatically when GDB is configured for the SH.
6611 As usual, a variety of small fixes and improvements, both generic
6612 and configuration-specific. See the ChangeLog for more detail.
6614 *** Changes in GDB-4.12:
6616 * Irix 5 is now supported
6620 GDB-4.12 on the HPPA has a number of changes which make it unable
6621 to debug the output from the currently released versions of GCC and
6622 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6623 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6624 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6627 *** Changes in GDB-4.11:
6629 * User visible changes:
6633 The "set remotedebug" option is now consistent between the mips remote
6634 target, remote targets using the gdb-specific protocol, UDI (AMD's
6635 debug protocol for the 29k) and the 88k bug monitor. It is now an
6636 integer specifying a debug level (normally 0 or 1, but 2 means more
6637 debugging info for the mips target).
6639 * DEC Alpha native support
6641 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6642 debug info, but GDB works fairly well with the DEC compiler and should
6643 work with a future GCC release. See the README file for a few
6644 Alpha-specific notes.
6646 * Preliminary thread implementation
6648 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6650 * LynxOS native and target support for 386
6652 This release has been hosted on LynxOS 2.2, and also can be configured
6653 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6656 * Improvements in C++ mangling/demangling.
6658 This release has much better g++ debugging, specifically in name
6659 mangling/demangling, virtual function calls, print virtual table,
6660 call methods, ...etc.
6662 *** Changes in GDB-4.10:
6664 * User visible changes:
6666 Remote debugging using the GDB-specific (`target remote') protocol now
6667 supports the `load' command. This is only useful if you have some
6668 other way of getting the stub to the target system, and you can put it
6669 somewhere in memory where it won't get clobbered by the download.
6671 Filename completion now works.
6673 When run under emacs mode, the "info line" command now causes the
6674 arrow to point to the line specified. Also, "info line" prints
6675 addresses in symbolic form (as well as hex).
6677 All vxworks based targets now support a user settable option, called
6678 vxworks-timeout. This option represents the number of seconds gdb
6679 should wait for responses to rpc's. You might want to use this if
6680 your vxworks target is, perhaps, a slow software simulator or happens
6681 to be on the far side of a thin network line.
6685 This release contains support for using a DEC alpha as a GDB host for
6686 cross debugging. Native alpha debugging is not supported yet.
6689 *** Changes in GDB-4.9:
6693 This is the first GDB release which is accompanied by a matching testsuite.
6694 The testsuite requires installation of dejagnu, which should be available
6695 via ftp from most sites that carry GNU software.
6699 'Cfront' style demangling has had its name changed to 'ARM' style, to
6700 emphasize that it was written from the specifications in the C++ Annotated
6701 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6702 disclaimers, it still generated too much confusion with users attempting to
6703 use gdb with AT&T cfront.
6707 GDB now uses a standard remote interface to a simulator library.
6708 So far, the library contains simulators for the Zilog Z8001/2, the
6709 Hitachi H8/300, H8/500 and Super-H.
6711 * New targets supported
6713 H8/300 simulator h8300-hitachi-hms or h8300hms
6714 H8/500 simulator h8500-hitachi-hms or h8500hms
6715 SH simulator sh-hitachi-hms or sh
6716 Z8000 simulator z8k-zilog-none or z8ksim
6717 IDT MIPS board over serial line mips-idt-ecoff
6719 Cross-debugging to GO32 targets is supported. It requires a custom
6720 version of the i386-stub.c module which is integrated with the
6721 GO32 memory extender.
6723 * New remote protocols
6725 MIPS remote debugging protocol.
6727 * New source languages supported
6729 This version includes preliminary support for Chill, a Pascal like language
6730 used by telecommunications companies. Chill support is also being integrated
6731 into the GNU compiler, but we don't know when it will be publically available.
6734 *** Changes in GDB-4.8:
6736 * HP Precision Architecture supported
6738 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6739 version of this support was available as a set of patches from the
6740 University of Utah. GDB does not support debugging of programs
6741 compiled with the HP compiler, because HP will not document their file
6742 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6743 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6745 Many problems in the preliminary version have been fixed.
6747 * Faster and better demangling
6749 We have improved template demangling and fixed numerous bugs in the GNU style
6750 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6751 character types (wchar_t) are now supported. Demangling of each symbol is now
6752 only done once, and is cached when the symbol table for a file is read in.
6753 This results in a small increase in memory usage for C programs, a moderate
6754 increase in memory usage for C++ programs, and a fantastic speedup in
6757 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6758 from the specifications in the Annotated Reference Manual, which AT&T's
6759 compiler does not actually implement.
6761 * G++ multiple inheritance compiler problem
6763 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6764 inheritance lattices was reworked to properly discover ambiguities. We
6765 recently found an example which causes this new algorithm to fail in a
6766 very subtle way, producing bad debug information for those classes.
6767 The file 'gcc.patch' (in this directory) can be applied to gcc to
6768 circumvent the problem. A future GCC release will contain a complete
6771 The previous G++ debug info problem (mentioned below for the gdb-4.7
6772 release) is fixed in gcc version 2.3.2.
6774 * Improved configure script
6776 The `configure' script will now attempt to guess your system type if
6777 you don't supply a host system type. The old scheme of supplying a
6778 host system triplet is preferable over using this. All the magic is
6779 done in the new `config.guess' script. Examine it for details.
6781 We have also brought our configure script much more in line with the FSF's
6782 version. It now supports the --with-xxx options. In particular,
6783 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6784 The resulting GDB will not be able to read arbitrary object file formats --
6785 only the format ``expected'' to be used on the configured target system.
6786 We hope to make this the default in a future release.
6788 * Documentation improvements
6790 There's new internal documentation on how to modify GDB, and how to
6791 produce clean changes to the code. We implore people to read it
6792 before submitting changes.
6794 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6795 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6796 `info' files are also provided. To build `info' files from scratch,
6797 you will need the latest `makeinfo' release, which will be available in
6798 a future texinfo-X.Y release.
6800 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6801 We're not sure exactly which versions have this problem, but it has
6802 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6803 or better. If that isn't possible, there is a patch in
6804 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6805 around this problem.
6809 GDB now supports array constants that can be used in expressions typed in by
6810 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6811 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6814 The new directory `gdb/sparclite' contains a program that demonstrates
6815 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6817 * New native hosts supported
6819 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6820 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6822 * New targets supported
6824 AMD 29k family via UDI a29k-amd-udi or udi29k
6826 * New file formats supported
6828 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6829 HPUX core files, and SCO 3.2v2 core files.
6833 Attaching to processes now works again; thanks for the many bug reports.
6835 We have also stomped on a bunch of core dumps caused by
6836 printf_filtered("%s") problems.
6838 We eliminated a copyright problem on the rpc and ptrace header files
6839 for VxWorks, which was discovered at the last minute during the 4.7
6840 release. You should now be able to build a VxWorks GDB.
6842 You can now interrupt gdb while an attached process is running. This
6843 will cause the attached process to stop, and give control back to GDB.
6845 We fixed problems caused by using too many file descriptors
6846 for reading symbols from object files and libraries. This was
6847 especially a problem for programs that used many (~100) shared
6850 The `step' command now only enters a subroutine if there is line number
6851 information for the subroutine. Otherwise it acts like the `next'
6852 command. Previously, `step' would enter subroutines if there was
6853 any debugging information about the routine. This avoids problems
6854 when using `cc -g1' on MIPS machines.
6856 * Internal improvements
6858 GDB's internal interfaces have been improved to make it easier to support
6859 debugging of multiple languages in the future.
6861 GDB now uses a common structure for symbol information internally.
6862 Minimal symbols (derived from linkage symbols in object files), partial
6863 symbols (from a quick scan of debug information), and full symbols
6864 contain a common subset of information, making it easier to write
6865 shared code that handles any of them.
6867 * New command line options
6869 We now accept --silent as an alias for --quiet.
6873 The memory-mapped-malloc library is now licensed under the GNU Library
6874 General Public License.
6876 *** Changes in GDB-4.7:
6878 * Host/native/target split
6880 GDB has had some major internal surgery to untangle the support for
6881 hosts and remote targets. Now, when you configure GDB for a remote
6882 target, it will no longer load in all of the support for debugging
6883 local programs on the host. When fully completed and tested, this will
6884 ensure that arbitrary host/target combinations are possible.
6886 The primary conceptual shift is to separate the non-portable code in
6887 GDB into three categories. Host specific code is required any time GDB
6888 is compiled on that host, regardless of the target. Target specific
6889 code relates to the peculiarities of the target, but can be compiled on
6890 any host. Native specific code is everything else: it can only be
6891 built when the host and target are the same system. Child process
6892 handling and core file support are two common `native' examples.
6894 GDB's use of /proc for controlling Unix child processes is now cleaner.
6895 It has been split out into a single module under the `target_ops' vector,
6896 plus two native-dependent functions for each system that uses /proc.
6898 * New hosts supported
6900 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6901 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6902 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6904 * New targets supported
6906 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6907 68030 and CPU32 m68030-*-*, m68332-*-*
6909 * New native hosts supported
6911 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6912 (386bsd is not well tested yet)
6913 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6915 * New file formats supported
6917 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6918 supports reading of `a.out.adobe' object files, which are an a.out
6919 format extended with minimal information about multiple sections.
6923 `show copying' is the same as the old `info copying'.
6924 `show warranty' is the same as `info warrantee'.
6925 These were renamed for consistency. The old commands continue to work.
6927 `info handle' is a new alias for `info signals'.
6929 You can now define pre-command hooks, which attach arbitrary command
6930 scripts to any command. The commands in the hook will be executed
6931 prior to the user's command. You can also create a hook which will be
6932 executed whenever the program stops. See gdb.texinfo.
6936 We now deal with Cfront style name mangling, and can even extract type
6937 info from mangled symbols. GDB can automatically figure out which
6938 symbol mangling style your C++ compiler uses.
6940 Calling of methods and virtual functions has been improved as well.
6944 The crash that occured when debugging Sun Ansi-C compiled binaries is
6945 fixed. This was due to mishandling of the extra N_SO stabs output
6948 We also finally got Ultrix 4.2 running in house, and fixed core file
6949 support, with help from a dozen people on the net.
6951 John M. Farrell discovered that the reason that single-stepping was so
6952 slow on all of the Mips based platforms (primarily SGI and DEC) was
6953 that we were trying to demangle and lookup a symbol used for internal
6954 purposes on every instruction that was being stepped through. Changing
6955 the name of that symbol so that it couldn't be mistaken for a C++
6956 mangled symbol sped things up a great deal.
6958 Rich Pixley sped up symbol lookups in general by getting much smarter
6959 about when C++ symbol mangling is necessary. This should make symbol
6960 completion (TAB on the command line) much faster. It's not as fast as
6961 we'd like, but it's significantly faster than gdb-4.6.
6965 A new user controllable variable 'call_scratch_address' can
6966 specify the location of a scratch area to be used when GDB
6967 calls a function in the target. This is necessary because the
6968 usual method of putting the scratch area on the stack does not work
6969 in systems that have separate instruction and data spaces.
6971 We integrated changes to support the 29k UDI (Universal Debugger
6972 Interface), but discovered at the last minute that we didn't have all
6973 of the appropriate copyright paperwork. We are working with AMD to
6974 resolve this, and hope to have it available soon.
6978 We have sped up the remote serial line protocol, especially for targets
6979 with lots of registers. It now supports a new `expedited status' ('T')
6980 message which can be used in place of the existing 'S' status message.
6981 This allows the remote stub to send only the registers that GDB
6982 needs to make a quick decision about single-stepping or conditional
6983 breakpoints, eliminating the need to fetch the entire register set for
6984 each instruction being stepped through.
6986 The GDB remote serial protocol now implements a write-through cache for
6987 registers, only re-reading the registers if the target has run.
6989 There is also a new remote serial stub for SPARC processors. You can
6990 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6991 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6992 processor with a serial port.
6996 Configure.in files have become much easier to read and modify. A new
6997 `table driven' format makes it more obvious what configurations are
6998 supported, and what files each one uses.
7002 There is a new opcodes library which will eventually contain all of the
7003 disassembly routines and opcode tables. At present, it only contains
7004 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7005 disassembler (binutils/objdump) to share these routines.
7007 The libiberty library is now copylefted under the GNU Library General
7008 Public License. This allows more liberal use, and was done so libg++
7009 can use it. This makes no difference to GDB, since the Library License
7010 grants all the rights from the General Public License.
7014 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7015 reference to the stabs symbol info used by the debugger. It is (as far
7016 as we know) the only published document on this fascinating topic. We
7017 encourage you to read it, compare it to the stabs information on your
7018 system, and send improvements on the document in general (to
7019 bug-gdb@prep.ai.mit.edu).
7021 And, of course, many bugs have been fixed.
7024 *** Changes in GDB-4.6:
7026 * Better support for C++ function names
7028 GDB now accepts as input the "demangled form" of C++ overloaded function
7029 names and member function names, and can do command completion on such names
7030 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7031 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7032 Make use of command completion, it is your friend.
7034 GDB also now accepts a variety of C++ mangled symbol formats. They are
7035 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7036 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7037 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7038 for the list of formats.
7040 * G++ symbol mangling problem
7042 Recent versions of gcc have a bug in how they emit debugging information for
7043 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7044 directory) can be applied to gcc to fix the problem. Alternatively, if you
7045 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7046 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7047 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7050 * New 'maintenance' command
7052 All of the commands related to hacking GDB internals have been moved out of
7053 the main command set, and now live behind the 'maintenance' command. This
7054 can also be abbreviated as 'mt'. The following changes were made:
7056 dump-me -> maintenance dump-me
7057 info all-breakpoints -> maintenance info breakpoints
7058 printmsyms -> maintenance print msyms
7059 printobjfiles -> maintenance print objfiles
7060 printpsyms -> maintenance print psymbols
7061 printsyms -> maintenance print symbols
7063 The following commands are new:
7065 maintenance demangle Call internal GDB demangler routine to
7066 demangle a C++ link name and prints the result.
7067 maintenance print type Print a type chain for a given symbol
7069 * Change to .gdbinit file processing
7071 We now read the $HOME/.gdbinit file before processing the argv arguments
7072 (e.g. reading symbol files or core files). This allows global parameters to
7073 be set, which will apply during the symbol reading. The ./.gdbinit is still
7074 read after argv processing.
7076 * New hosts supported
7078 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7080 GNU/Linux support i386-unknown-linux or linux
7082 We are also including code to support the HP/PA running BSD and HPUX. This
7083 is almost guaranteed not to work, as we didn't have time to test or build it
7084 for this release. We are including it so that the more adventurous (or
7085 masochistic) of you can play with it. We also had major problems with the
7086 fact that the compiler that we got from HP doesn't support the -g option.
7089 * New targets supported
7091 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7093 * More smarts about finding #include files
7095 GDB now remembers the compilation directory for all include files, and for
7096 all files from which C is generated (like yacc and lex sources). This
7097 greatly improves GDB's ability to find yacc/lex sources, and include files,
7098 especially if you are debugging your program from a directory different from
7099 the one that contains your sources.
7101 We also fixed a bug which caused difficulty with listing and setting
7102 breakpoints in include files which contain C code. (In the past, you had to
7103 try twice in order to list an include file that you hadn't looked at before.)
7105 * Interesting infernals change
7107 GDB now deals with arbitrary numbers of sections, where the symbols for each
7108 section must be relocated relative to that section's landing place in the
7109 target's address space. This work was needed to support ELF with embedded
7110 stabs used by Solaris-2.0.
7112 * Bug fixes (of course!)
7114 There have been loads of fixes for the following things:
7115 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7116 i960, stabs, DOS(GO32), procfs, etc...
7118 See the ChangeLog for details.
7120 *** Changes in GDB-4.5:
7122 * New machines supported (host and target)
7124 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7126 SGI Irix-4.x mips-sgi-irix4 or iris4
7128 * New malloc package
7130 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7131 Mmalloc is capable of handling mutiple heaps of memory. It is also
7132 capable of saving a heap to a file, and then mapping it back in later.
7133 This can be used to greatly speedup the startup of GDB by using a
7134 pre-parsed symbol table which lives in a mmalloc managed heap. For
7135 more details, please read mmalloc/mmalloc.texi.
7139 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7140 'help info proc' for details.
7142 * MIPS ecoff symbol table format
7144 The code that reads MIPS symbol table format is now supported on all hosts.
7145 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7148 * File name changes for MS-DOS
7150 Many files in the config directories have been renamed to make it easier to
7151 support GDB on MS-DOSe systems (which have very restrictive file name
7152 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7153 environment) is close to working but has some remaining problems. Note
7154 that debugging of DOS programs is not supported, due to limitations
7155 in the ``operating system'', but it can be used to host cross-debugging.
7157 * Cross byte order fixes
7159 Many fixes have been made to support cross debugging of Sparc and MIPS
7160 targets from hosts whose byte order differs.
7162 * New -mapped and -readnow options
7164 If memory-mapped files are available on your system through the 'mmap'
7165 system call, you can use the -mapped option on the `file' or
7166 `symbol-file' commands to cause GDB to write the symbols from your
7167 program into a reusable file. If the program you are debugging is
7168 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7169 Future GDB debugging sessions will notice the presence of this file,
7170 and will quickly map in symbol information from it, rather than reading
7171 the symbol table from the executable program. Using the '-mapped'
7172 option in a GDB `file' or `symbol-file' command has the same effect as
7173 starting GDB with the '-mapped' command-line option.
7175 You can cause GDB to read the entire symbol table immediately by using
7176 the '-readnow' option with any of the commands that load symbol table
7177 information (or on the GDB command line). This makes the command
7178 slower, but makes future operations faster.
7180 The -mapped and -readnow options are typically combined in order to
7181 build a `fred.syms' file that contains complete symbol information.
7182 A simple GDB invocation to do nothing but build a `.syms' file for future
7185 gdb -batch -nx -mapped -readnow programname
7187 The `.syms' file is specific to the host machine on which GDB is run.
7188 It holds an exact image of GDB's internal symbol table. It cannot be
7189 shared across multiple host platforms.
7191 * longjmp() handling
7193 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7194 siglongjmp() without losing control. This feature has not yet been ported to
7195 all systems. It currently works on many 386 platforms, all MIPS-based
7196 platforms (SGI, DECstation, etc), and Sun3/4.
7200 Preliminary work has been put in to support the new Solaris OS from Sun. At
7201 this time, it can control and debug processes, but it is not capable of
7206 As always, many many bug fixes. The major areas were with g++, and mipsread.
7207 People using the MIPS-based platforms should experience fewer mysterious
7208 crashes and trashed symbol tables.
7210 *** Changes in GDB-4.4:
7212 * New machines supported (host and target)
7214 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7216 BSD Reno on Vax vax-dec-bsd
7217 Ultrix on Vax vax-dec-ultrix
7219 * New machines supported (target)
7221 AMD 29000 embedded, using EBMON a29k-none-none
7225 GDB continues to improve its handling of C++. `References' work better.
7226 The demangler has also been improved, and now deals with symbols mangled as
7227 per the Annotated C++ Reference Guide.
7229 GDB also now handles `stabs' symbol information embedded in MIPS
7230 `ecoff' symbol tables. Since the ecoff format was not easily
7231 extensible to handle new languages such as C++, this appeared to be a
7232 good way to put C++ debugging info into MIPS binaries. This option
7233 will be supported in the GNU C compiler, version 2, when it is
7236 * New features for SVR4
7238 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7239 shared libraries. Debugging dynamically linked programs should present
7240 only minor differences from debugging statically linked programs.
7242 The `info proc' command will print out information about any process
7243 on an SVR4 system (including the one you are debugging). At the moment,
7244 it prints the address mappings of the process.
7246 If you bring up GDB on another SVR4 system, please send mail to
7247 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7249 * Better dynamic linking support in SunOS
7251 Reading symbols from shared libraries which contain debugging symbols
7252 now works properly. However, there remain issues such as automatic
7253 skipping of `transfer vector' code during function calls, which
7254 make it harder to debug code in a shared library, than to debug the
7255 same code linked statically.
7259 GDB is now using the latest `getopt' routines from the FSF. This
7260 version accepts the -- prefix for options with long names. GDB will
7261 continue to accept the old forms (-option and +option) as well.
7262 Various single letter abbreviations for options have been explicity
7263 added to the option table so that they won't get overshadowed in the
7264 future by other options that begin with the same letter.
7268 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7269 Many assorted bugs have been handled. Many more remain to be handled.
7270 See the various ChangeLog files (primarily in gdb and bfd) for details.
7273 *** Changes in GDB-4.3:
7275 * New machines supported (host and target)
7277 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7278 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7279 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7281 * Almost SCO Unix support
7283 We had hoped to support:
7284 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7285 (except for core file support), but we discovered very late in the release
7286 that it has problems with process groups that render gdb unusable. Sorry
7287 about that. I encourage people to fix it and post the fixes.
7289 * Preliminary ELF and DWARF support
7291 GDB can read ELF object files on System V Release 4, and can handle
7292 debugging records for C, in DWARF format, in ELF files. This support
7293 is preliminary. If you bring up GDB on another SVR4 system, please
7294 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7299 GDB now uses the latest `readline' library. One user-visible change
7300 is that two tabs will list possible command completions, which previously
7301 required typing M-? (meta-question mark, or ESC ?).
7305 The `stepi' bug that many of you noticed has been squashed.
7306 Many bugs in C++ have been handled. Many more remain to be handled.
7307 See the various ChangeLog files (primarily in gdb and bfd) for details.
7309 * State of the MIPS world (in case you wondered):
7311 GDB can understand the symbol tables emitted by the compilers
7312 supplied by most vendors of MIPS-based machines, including DEC. These
7313 symbol tables are in a format that essentially nobody else uses.
7315 Some versions of gcc come with an assembler post-processor called
7316 mips-tfile. This program is required if you want to do source-level
7317 debugging of gcc-compiled programs. I believe FSF does not ship
7318 mips-tfile with gcc version 1, but it will eventually come with gcc
7321 Debugging of g++ output remains a problem. g++ version 1.xx does not
7322 really support it at all. (If you're lucky, you should be able to get
7323 line numbers and stack traces to work, but no parameters or local
7324 variables.) With some work it should be possible to improve the
7327 When gcc version 2 is released, you will have somewhat better luck.
7328 However, even then you will get confusing results for inheritance and
7331 We will eventually provide full debugging of g++ output on
7332 DECstations. This will probably involve some kind of stabs-in-ecoff
7333 encapulation, but the details have not been worked out yet.
7336 *** Changes in GDB-4.2:
7338 * Improved configuration
7340 Only one copy of `configure' exists now, and it is not self-modifying.
7341 Porting BFD is simpler.
7345 The `step' and `next' commands now only stop at the first instruction
7346 of a source line. This prevents the multiple stops that used to occur
7347 in switch statements, for-loops, etc. `Step' continues to stop if a
7348 function that has debugging information is called within the line.
7352 Lots of small bugs fixed. More remain.
7354 * New host supported (not target)
7356 Intel 386 PC clone running Mach i386-none-mach
7359 *** Changes in GDB-4.1:
7361 * Multiple source language support
7363 GDB now has internal scaffolding to handle several source languages.
7364 It determines the type of each source file from its filename extension,
7365 and will switch expression parsing and number formatting to match the
7366 language of the function in the currently selected stack frame.
7367 You can also specifically set the language to be used, with
7368 `set language c' or `set language modula-2'.
7372 GDB now has preliminary support for the GNU Modula-2 compiler,
7373 currently under development at the State University of New York at
7374 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7375 continue through the fall of 1991 and into 1992.
7377 Other Modula-2 compilers are currently not supported, and attempting to
7378 debug programs compiled with them will likely result in an error as the
7379 symbol table is read. Feel free to work on it, though!
7381 There are hooks in GDB for strict type checking and range checking,
7382 in the `Modula-2 philosophy', but they do not currently work.
7386 GDB can now write to executable and core files (e.g. patch
7387 a variable's value). You must turn this switch on, specify
7388 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7389 by assigning a new value to a variable. Modifications take
7392 * Automatic SunOS shared library reading
7394 When you run your program, GDB automatically determines where its
7395 shared libraries (if any) have been loaded, and reads their symbols.
7396 The `share' command is no longer needed. This also works when
7397 examining core files.
7401 You can specify the number of lines that the `list' command shows.
7404 * New machines supported (host and target)
7406 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7407 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7408 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7410 * New hosts supported (not targets)
7412 IBM RT/PC: romp-ibm-aix or rtpc
7414 * New targets supported (not hosts)
7416 AMD 29000 embedded with COFF a29k-none-coff
7417 AMD 29000 embedded with a.out a29k-none-aout
7418 Ultracomputer remote kernel debug a29k-nyu-kern
7420 * New remote interfaces
7426 *** Changes in GDB-4.0:
7430 Wide output is wrapped at good places to make the output more readable.
7432 Gdb now supports cross-debugging from a host machine of one type to a
7433 target machine of another type. Communication with the target system
7434 is over serial lines. The ``target'' command handles connecting to the
7435 remote system; the ``load'' command will download a program into the
7436 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7437 also supports debugging of realtime processes running under VxWorks,
7438 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7439 stub on the target system.
7441 New CPUs supported include the AMD 29000 and Intel 960.
7443 GDB now reads object files and symbol tables via a ``binary file''
7444 library, which allows a single copy of GDB to debug programs of multiple
7445 object file types such as a.out and coff.
7447 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7448 refcard.dvi and refcard.ps are available to format it).
7451 * Control-Variable user interface simplified
7453 All variables that control the operation of the debugger can be set
7454 by the ``set'' command, and displayed by the ``show'' command.
7456 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7457 ``Show prompt'' produces the response:
7458 Gdb's prompt is new-gdb=>.
7460 What follows are the NEW set commands. The command ``help set'' will
7461 print a complete list of old and new set commands. ``help set FOO''
7462 will give a longer description of the variable FOO. ``show'' will show
7463 all of the variable descriptions and their current settings.
7465 confirm on/off: Enables warning questions for operations that are
7466 hard to recover from, e.g. rerunning the program while
7467 it is already running. Default is ON.
7469 editing on/off: Enables EMACS style command line editing
7470 of input. Previous lines can be recalled with
7471 control-P, the current line can be edited with control-B,
7472 you can search for commands with control-R, etc.
7475 history filename NAME: NAME is where the gdb command history
7476 will be stored. The default is .gdb_history,
7477 or the value of the environment variable
7480 history size N: The size, in commands, of the command history. The
7481 default is 256, or the value of the environment variable
7484 history save on/off: If this value is set to ON, the history file will
7485 be saved after exiting gdb. If set to OFF, the
7486 file will not be saved. The default is OFF.
7488 history expansion on/off: If this value is set to ON, then csh-like
7489 history expansion will be performed on
7490 command line input. The default is OFF.
7492 radix N: Sets the default radix for input and output. It can be set
7493 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7494 in the current radix, so "set radix 10" is always a no-op.
7496 height N: This integer value is the number of lines on a page. Default
7497 is 24, the current `stty rows'' setting, or the ``li#''
7498 setting from the termcap entry matching the environment
7501 width N: This integer value is the number of characters on a line.
7502 Default is 80, the current `stty cols'' setting, or the ``co#''
7503 setting from the termcap entry matching the environment
7506 Note: ``set screensize'' is obsolete. Use ``set height'' and
7507 ``set width'' instead.
7509 print address on/off: Print memory addresses in various command displays,
7510 such as stack traces and structure values. Gdb looks
7511 more ``symbolic'' if you turn this off; it looks more
7512 ``machine level'' with it on. Default is ON.
7514 print array on/off: Prettyprint arrays. New convenient format! Default
7517 print demangle on/off: Print C++ symbols in "source" form if on,
7520 print asm-demangle on/off: Same, for assembler level printouts
7523 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7526 * Support for Epoch Environment.
7528 The epoch environment is a version of Emacs v18 with windowing. One
7529 new command, ``inspect'', is identical to ``print'', except that if you
7530 are running in the epoch environment, the value is printed in its own
7534 * Support for Shared Libraries
7536 GDB can now debug programs and core files that use SunOS shared libraries.
7537 Symbols from a shared library cannot be referenced
7538 before the shared library has been linked with the program (this
7539 happens after you type ``run'' and before the function main() is entered).
7540 At any time after this linking (including when examining core files
7541 from dynamically linked programs), gdb reads the symbols from each
7542 shared library when you type the ``sharedlibrary'' command.
7543 It can be abbreviated ``share''.
7545 sharedlibrary REGEXP: Load shared object library symbols for files
7546 matching a unix regular expression. No argument
7547 indicates to load symbols for all shared libraries.
7549 info sharedlibrary: Status of loaded shared libraries.
7554 A watchpoint stops execution of a program whenever the value of an
7555 expression changes. Checking for this slows down execution
7556 tremendously whenever you are in the scope of the expression, but is
7557 quite useful for catching tough ``bit-spreader'' or pointer misuse
7558 problems. Some machines such as the 386 have hardware for doing this
7559 more quickly, and future versions of gdb will use this hardware.
7561 watch EXP: Set a watchpoint (breakpoint) for an expression.
7563 info watchpoints: Information about your watchpoints.
7565 delete N: Deletes watchpoint number N (same as breakpoints).
7566 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7567 enable N: Re-enables watchpoint number N (same as breakpoints).
7570 * C++ multiple inheritance
7572 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7575 * C++ exception handling
7577 Gdb now supports limited C++ exception handling. Besides the existing
7578 ability to breakpoint on an exception handler, gdb can breakpoint on
7579 the raising of an exception (before the stack is peeled back to the
7582 catch FOO: If there is a FOO exception handler in the dynamic scope,
7583 set a breakpoint to catch exceptions which may be raised there.
7584 Multiple exceptions (``catch foo bar baz'') may be caught.
7586 info catch: Lists all exceptions which may be caught in the
7587 current stack frame.
7590 * Minor command changes
7592 The command ``call func (arg, arg, ...)'' now acts like the print
7593 command, except it does not print or save a value if the function's result
7594 is void. This is similar to dbx usage.
7596 The ``up'' and ``down'' commands now always print the frame they end up
7597 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7598 frames without printing.
7600 * New directory command
7602 'dir' now adds directories to the FRONT of the source search path.
7603 The path starts off empty. Source files that contain debug information
7604 about the directory in which they were compiled can be found even
7605 with an empty path; Sun CC and GCC include this information. If GDB can't
7606 find your source file in the current directory, type "dir .".
7608 * Configuring GDB for compilation
7610 For normal use, type ``./configure host''. See README or gdb.texinfo
7613 GDB now handles cross debugging. If you are remotely debugging between
7614 two different machines, type ``./configure host -target=targ''.
7615 Host is the machine where GDB will run; targ is the machine
7616 where the program that you are debugging will run.