1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.3
6 * 'thread-exited' event is now available in the annotations interface.
8 * New built-in convenience variables $_gdb_major and $_gdb_minor
9 provide the GDB version. They are handy for conditionally using
10 features available only in or since specific GDB versions, in
11 scripts that should work error-free with many different versions,
12 such as in system-wide init files.
14 * GDB now supports Thread Local Storage (TLS) variables on several
15 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
16 architectures require kernel changes. TLS is not yet supported for
17 amd64 and i386 process core dumps.
19 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
20 addresses that required unmasking are shown in the backtrace with the
23 * Two new convenience functions $_cimag and $_creal that extract the
24 imaginary and real parts respectively from complex numbers.
26 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
27 provide the exitcode or exit status of the shell commands launched by
28 GDB commands such as "shell", "pipe" and "make".
30 * The RX port now supports XML target descriptions.
32 * GDB now shows the Ada task names at more places, e.g. in task switching
35 * GDB can now be compiled with Python 3 on Windows.
39 ** The gdb.Value type has a new method 'format_string' which returns a
40 string representing the value. The formatting is controlled by the
41 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
42 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
43 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
45 ** gdb.Type has a new property 'objfile' which returns the objfile the
48 ** The frame information printed by the python frame filtering code
49 is now consistent with what the 'backtrace' command prints when
50 there are no filters, or when the 'backtrace' '-no-filters' option
53 ** The new function gdb.lookup_static_symbol can be used to look up
54 symbols with static linkage.
56 ** gdb.Objfile has new methods 'lookup_global_symbol' and
57 'lookup_static_symbol' to lookup a symbol from this objfile only.
59 ** gdb.Block now supports the dictionary syntax for accessing symbols in
60 this block (e.g. block['local_variable']).
64 | [COMMAND] | SHELL_COMMAND
65 | -d DELIM COMMAND DELIM SHELL_COMMAND
66 pipe [COMMAND] | SHELL_COMMAND
67 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
68 Executes COMMAND and sends its output to SHELL_COMMAND.
69 With no COMMAND, repeat the last executed command
70 and send its output to SHELL_COMMAND.
72 with SETTING [VALUE] [-- COMMAND]
73 w SETTING [VALUE] [-- COMMAND]
74 Temporarily set SETTING, run COMMAND, and restore SETTING.
75 Usage: with SETTING -- COMMAND
76 With no COMMAND, repeats the last executed command.
77 SETTING is any GDB setting you can change with the "set"
78 subcommands. For example, 'with language c -- print someobj'
79 temporarily switches to the C language in order to print someobj.
80 Settings can be combined: 'w lang c -- w print elements unlimited --
81 usercmd' switches to the C language and runs usercmd with no limit
82 of array elements to print.
84 maint with SETTING [VALUE] [-- COMMAND]
85 Like "with", but works with "maintenance set" settings.
87 set may-call-functions [on|off]
88 show may-call-functions
89 This controls whether GDB will attempt to call functions in
90 the program, such as with expressions in the print command. It
91 defaults to on. Calling functions in the program being debugged
92 can have undesired side effects. It is now possible to forbid
93 such function calls. If function calls are forbidden, GDB will throw
94 an error when a command (such as print expression) calls a function
97 set print finish [on|off]
99 This controls whether the `finish' command will display the value
100 that is returned by the current function. When `off', the value is
101 still entered into the value history, but it is not printed. The
106 Allows deeply nested structures to be simplified when printing by
107 replacing deeply nested parts (beyond the max-depth) with ellipses.
108 The default max-depth is 20, but this can be set to unlimited to get
109 the old behavior back.
111 set logging debugredirect [on|off]
112 By default, GDB debug output will go to both the terminal and the logfile.
113 Set if you want debug output to go only to the log file.
115 set style title foreground COLOR
116 set style title background COLOR
117 set style title intensity VALUE
118 Control the styling of titles.
120 set style highlight foreground COLOR
121 set style highlight background COLOR
122 set style highlight intensity VALUE
123 Control the styling of highlightings.
125 maint set test-settings KIND
126 maint show test-settings KIND
127 A set of commands used by the testsuite for exercising the settings
130 set print frame-info [short-location|location|location-and-address
131 |source-and-location|source-line|auto]
132 show print frame-info
133 This controls what frame information is printed by the commands printing
134 a frame. This setting will e.g. influence the behaviour of 'backtrace',
135 'frame', 'stepi'. The python frame filtering also respect this setting.
136 The 'backtrace' '-frame-info' option can override this global setting.
141 The "help" command uses the title style to enhance the
142 readibility of its output by styling the classes and
146 Similarly to "help", the "apropos" command also uses the
147 title style for the command names. "apropos" accepts now
148 a flag "-v" (verbose) to show the full documentation
149 of matching commands and to use the highlight style to mark
150 the documentation parts matching REGEXP.
154 The GDB printf and eval commands can now print C-style and Ada-style
155 string convenience variables without calling functions in the program.
156 This allows to do formatted printing of strings without having
157 a running inferior, or when debugging a core dump.
159 info sources [-dirname | -basename] [--] [REGEXP]
160 This command has now optional arguments to only print the files
161 whose names match REGEXP. The arguments -dirname and -basename
162 allow to restrict matching respectively to the dirname and basename
166 The "show style" and its subcommands are now styling
167 a style name in their output using its own style, to help
168 the user visualize the different styles.
170 set print frame-arguments
171 The new value 'presence' indicates to only indicate the presence of
172 arguments using ..., instead of printing argument names and values.
174 set print raw-frame-arguments
175 show print raw-frame-arguments
177 These commands replace the similarly-named "set/show print raw
178 frame-arguments" commands (now with a dash instead of a space). The
179 old commands are now deprecated and may be removed in a future
182 maint test-options require-delimiter
183 maint test-options unknown-is-error
184 maint test-options unknown-is-operand
185 maint show test-options-completion-result
186 Commands used by the testsuite to validate the command options
189 focus, winheight, +, -, >, <
190 These commands are now case-sensitive.
192 * New command options, command completion
194 GDB now has a standard infrastructure to support dash-style command
195 options ('-OPT'). One benefit is that commands that use it can
196 easily support completion of command line arguments. Try "CMD
197 -[TAB]" or "help CMD" to find options supported by a command. Over
198 time, we intend to migrate most commands to this infrastructure. A
199 number of commands got support for new command options in this
202 ** The "print" and "compile print" commands now support a number of
203 options that allow overriding relevant global print settings as
204 set by "set print" subcommands:
208 -array-indexes [on|off]
209 -elements NUMBER|unlimited
213 -repeats NUMBER|unlimited
214 -static-members [on|off]
219 Note that because the "print"/"compile print" commands accept
220 arbitrary expressions which may look like options (including
221 abbreviations), if you specify any command option, then you must
222 use a double dash ("--") to mark the end of argument processing.
224 ** The "backtrace" command now supports a number of options that
225 allow overriding relevant global print settings as set by "set
226 backtrace" and "set print" subcommands:
228 -entry-values no|only|preferred|if-needed|both|compact|default
229 -frame-arguments all|scalars|none
230 -raw-frame-arguments [on|off]
231 -frame-info auto|source-line|location|source-and-location
232 |location-and-address|short-location
236 In addition, the full/no-filters/hide qualifiers are now also
237 exposed as command options too:
243 ** The "frame apply", "tfaas" and "faas" commands similarly now
244 support the following options:
249 ** The new "info sources" options -dirname and -basename options
250 are using the standard '-OPT' infrastructure.
252 All options above can also be abbreviated. The argument of boolean
253 (on/off) options can be 0/1 too, and also the argument is assumed
254 "on" if omitted. This allows writing compact command invocations,
257 (gdb) p -r -p -o 0 -- *myptr
259 The above is equivalent to:
261 (gdb) print -raw -pretty -object off -- *myptr
263 ** The "info types" command now supports the '-q' flag to disable
264 printing of some header information in a similar fashion to "info
265 variables" and "info functions".
267 ** The "info variables", "info functions", and "whereis" commands
268 now take a '-n' flag that excludes non-debug symbols (symbols
269 from the symbol table, not from the debug info such as DWARF)
272 * Completion improvements
274 ** GDB can now complete the options of the "thread apply all" and
275 "taas" commands, and their "-ascending" option can now be
278 ** GDB can now complete the options of the "info threads", "info
279 functions", "info variables", "info locals", and "info args"
282 ** GDB can now complete the options of the "compile file" and
283 "compile code" commands. The "compile file" command now
284 completes on filenames.
286 ** GDB can now complete the backtrace command's
287 "full/no-filters/hide" qualifiers.
289 * In settings, you can now abbreviate "unlimited".
291 E.g., "set print elements u" is now equivalent to "set print
297 This lists all the possible completions for the rest of the line, if it
298 were to be given as a command itself. This is intended for use by MI
299 frontends in cases when separate CLI and MI channels cannot be used.
301 -catch-throw, -catch-rethrow, and -catch-catch
302 These can be used to catch C++ exceptions in a similar fashion to
303 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
307 ** Backtraces and frames include a new optional field addr_flags which is
308 given after the addr field. On AArch64 this contains PAC if the address
309 has been masked in the frame. On all other targets the field is not
314 The testsuite now creates the files gdb.cmd (containing the arguments
315 used to launch GDB) and gdb.in (containing all the commands sent to
316 GDB) in the output directory for each test script. Multiple invocations
317 are appended with .1, .2, .3 etc.
319 * Building GDB and GDBserver now requires GNU make >= 3.82.
321 Using another implementation of the make program or an earlier version of
322 GNU make to build GDB or GDBserver is not supported.
324 * Building GDB now requires GNU readline >= 7.0.
326 GDB now bundles GNU readline 8.0, but if you choose to use
327 --with-system-readline, only readline >= 7.0 can be used.
329 * The TUI SingleKey keymap is now named "SingleKey". This can be used
330 from .inputrc to bind keys in this keymap. This feature is only
331 available when gdb is built against GNU readline 8.0 or later.
333 * Removed targets and native configurations
335 GDB no longer supports debugging the Cell Broadband Engine. This includes
336 both debugging standalone Cell/B.E. SPU applications and integrated debugging
337 of Cell/B.E. applications that use both the PPU and SPU architectures.
339 *** Changes in GDB 8.3
341 * GDB and GDBserver now support access to additional registers on
342 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
345 * GDB now has experimental support for the compilation and injection of
346 C++ source code into the inferior. This beta release does not include
347 support for several language features, such as templates, constructors,
350 This feature requires GCC 7.1 or higher built with libcp1.so
353 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
354 can be passed using the '[ADDRESS]:PORT' notation, or the regular
355 'ADDRESS:PORT' method.
357 * DWARF index cache: GDB can now automatically save indices of DWARF
358 symbols on disk to speed up further loading of the same binaries.
360 * Ada task switching is now supported on aarch64-elf targets when
361 debugging a program using the Ravenscar Profile. For more information,
362 see the "Tasking Support when using the Ravenscar Profile" section
363 in the GDB user manual.
365 * GDB in batch mode now exits with status 1 if the last command to be
368 * The RISC-V target now supports target descriptions.
370 * System call catchpoints now support system call aliases on FreeBSD.
371 When the ABI of a system call changes in FreeBSD, this is
372 implemented by leaving a compatibility system call using the old ABI
373 at the existing number and allocating a new system call number for
374 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
375 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
376 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
377 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
378 so that a system call catchpoint for the 'kevent' system call will
379 catch invocations of both the 'kevent' and 'freebsd11_kevent'
380 binaries. This ensures that 'kevent' system calls are caught for
381 binaries using either the old or new ABIs.
383 * Terminal styling is now available for the CLI and the TUI. GNU
384 Source Highlight can additionally be used to provide styling of
385 source code snippets. See the "set style" commands, below, for more
388 * Removed support for old demangling styles arm, edg, gnu, hp and
393 set debug compile-cplus-types
394 show debug compile-cplus-types
395 Control the display of debug output about type conversion in the
396 C++ compile feature. Commands have no effect while compiliong
401 Control whether debug output about files/functions skipping is
404 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
405 Apply a command to some frames.
406 FLAG arguments allow to control what output to produce and how to handle
407 errors raised when applying COMMAND to a frame.
410 Apply a command to all threads (ignoring errors and empty output).
411 Shortcut for 'thread apply all -s COMMAND'.
414 Apply a command to all frames (ignoring errors and empty output).
415 Shortcut for 'frame apply all -s COMMAND'.
418 Apply a command to all frames of all threads (ignoring errors and empty
420 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
422 maint set dwarf unwinders (on|off)
423 maint show dwarf unwinders
424 Control whether DWARF unwinders can be used.
427 Display a list of open files for a process.
431 Changes to the "frame", "select-frame", and "info frame" CLI commands.
432 These commands all now take a frame specification which
433 is either a frame level, or one of the keywords 'level', 'address',
434 'function', or 'view' followed by a parameter. Selecting a frame by
435 address, or viewing a frame outside the current backtrace now
436 requires the use of a keyword. Selecting a frame by level is
437 unchanged. The MI comment "-stack-select-frame" is unchanged.
439 target remote FILENAME
440 target extended-remote FILENAME
441 If FILENAME is a Unix domain socket, GDB will attempt to connect
442 to this socket instead of opening FILENAME as a character device.
444 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
445 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
446 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
447 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
448 These commands can now print only the searched entities
449 matching the provided regexp(s), giving a condition
450 on the entity names or entity types. The flag -q disables
451 printing headers or informations messages.
457 These commands now determine the syntax for the shown entities
458 according to the language chosen by `set language'. In particular,
459 `set language auto' means to automatically choose the language of
462 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
463 The 'thread apply' command accepts new FLAG arguments.
464 FLAG arguments allow to control what output to produce and how to handle
465 errors raised when applying COMMAND to a thread.
467 set tui tab-width NCHARS
468 show tui tab-width NCHARS
469 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
471 set style enabled [on|off]
473 Enable or disable terminal styling. Styling is enabled by default
474 on most hosts, but disabled by default when in batch mode.
476 set style sources [on|off]
478 Enable or disable source code styling. Source code styling is
479 enabled by default, but only takes effect if styling in general is
480 enabled, and if GDB was linked with GNU Source Highlight.
482 set style filename foreground COLOR
483 set style filename background COLOR
484 set style filename intensity VALUE
485 Control the styling of file names.
487 set style function foreground COLOR
488 set style function background COLOR
489 set style function intensity VALUE
490 Control the styling of function names.
492 set style variable foreground COLOR
493 set style variable background COLOR
494 set style variable intensity VALUE
495 Control the styling of variable names.
497 set style address foreground COLOR
498 set style address background COLOR
499 set style address intensity VALUE
500 Control the styling of addresses.
504 ** The default version of the MI interpreter is now 3 (-i=mi3).
506 ** The '-data-disassemble' MI command now accepts an '-a' option to
507 disassemble the whole function surrounding the given program
508 counter value or function name. Support for this feature can be
509 verified by using the "-list-features" command, which should
510 contain "data-disassemble-a-option".
512 ** Command responses and notifications that include a frame now include
513 the frame's architecture in a new "arch" attribute.
515 ** The output of information about multi-location breakpoints (which is
516 syntactically incorrect in MI 2) has changed in MI 3. This affects
517 the following commands and events:
521 - =breakpoint-created
522 - =breakpoint-modified
524 The -fix-multi-location-breakpoint-output command can be used to enable
525 this behavior with previous MI versions.
527 * New native configurations
529 GNU/Linux/RISC-V riscv*-*-linux*
530 FreeBSD/riscv riscv*-*-freebsd*
534 GNU/Linux/RISC-V riscv*-*-linux*
536 CSKY GNU/LINUX csky*-*-linux
537 FreeBSD/riscv riscv*-*-freebsd*
539 GNU/Linux/OpenRISC or1k*-*-linux*
543 GDB no longer supports native debugging on versions of MS-Windows
548 ** GDB no longer supports Python versions less than 2.6.
550 ** The gdb.Inferior type has a new 'progspace' property, which is the program
551 space associated to that inferior.
553 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
554 of objfiles associated to that program space.
556 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
557 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
560 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
561 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
562 correct and did not work properly.
564 ** The gdb.Value type has a new constructor, which is used to construct a
565 gdb.Value from a Python buffer object and a gdb.Type.
571 Enable or disable the undefined behavior sanitizer. This is
572 disabled by default, but passing --enable-ubsan=yes or
573 --enable-ubsan=auto to configure will enable it. Enabling this can
574 cause a performance penalty. The undefined behavior sanitizer was
575 first introduced in GCC 4.9.
577 *** Changes in GDB 8.2
579 * The 'set disassembler-options' command now supports specifying options
582 * The 'symbol-file' command now accepts an '-o' option to add a relative
583 offset to all sections.
585 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
586 a relative offset to all sections, but it allows to override the load
587 address of individual sections using '-s'.
589 * The 'add-symbol-file' command no longer requires the second argument
590 (address of the text section).
592 * The endianness used with the 'set endian auto' mode in the absence of
593 an executable selected for debugging is now the last endianness chosen
594 either by one of the 'set endian big' and 'set endian little' commands
595 or by inferring from the last executable used, rather than the startup
598 * The pager now allows a "c" response, meaning to disable the pager
599 for the rest of the current command.
601 * The commands 'info variables/functions/types' now show the source line
602 numbers of symbol definitions when available.
604 * 'info proc' now works on running processes on FreeBSD systems and core
605 files created on FreeBSD systems.
607 * C expressions can now use _Alignof, and C++ expressions can now use
610 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
611 the vector length while the process is running.
617 Control display of debugging info regarding the FreeBSD native target.
619 set|show varsize-limit
620 This new setting allows the user to control the maximum size of Ada
621 objects being printed when those objects have a variable type,
622 instead of that maximum size being hardcoded to 65536 bytes.
624 set|show record btrace cpu
625 Controls the processor to be used for enabling errata workarounds for
628 maint check libthread-db
629 Run integrity checks on the current inferior's thread debugging
632 maint set check-libthread-db (on|off)
633 maint show check-libthread-db
634 Control whether to run integrity checks on inferior specific thread
635 debugging libraries as they are loaded. The default is not to
640 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
642 ** The commands attached to a breakpoint can be set by assigning to
643 the breakpoint's "commands" field.
645 ** gdb.execute can now execute multi-line gdb commands.
647 ** The new functions gdb.convenience_variable and
648 gdb.set_convenience_variable can be used to get and set the value
649 of convenience variables.
651 ** A gdb.Parameter will no longer print the "set" help text on an
652 ordinary "set"; instead by default a "set" will be silent unless
653 the get_set_string method returns a non-empty string.
657 RiscV ELF riscv*-*-elf
659 * Removed targets and native configurations
661 m88k running OpenBSD m88*-*-openbsd*
662 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
663 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
664 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
666 * Aarch64/Linux hardware watchpoints improvements
668 Hardware watchpoints on unaligned addresses are now properly
669 supported when running Linux kernel 4.10 or higher: read and access
670 watchpoints are no longer spuriously missed, and all watchpoints
671 lengths between 1 and 8 bytes are supported. On older kernels,
672 watchpoints set on unaligned addresses are no longer missed, with
673 the tradeoff that there is a possibility of false hits being
678 --enable-codesign=CERT
679 This can be used to invoke "codesign -s CERT" after building gdb.
680 This option is useful on macOS, where code signing is required for
681 gdb to work properly.
683 --disable-gdbcli has been removed
684 This is now silently accepted, but does nothing.
686 *** Changes in GDB 8.1
688 * GDB now supports dynamically creating arbitrary register groups specified
689 in XML target descriptions. This allows for finer grain grouping of
690 registers on systems with a large amount of registers.
692 * The 'ptype' command now accepts a '/o' flag, which prints the
693 offsets and sizes of fields in a struct, like the pahole(1) tool.
695 * New "--readnever" command line option instructs GDB to not read each
696 symbol file's symbolic debug information. This makes startup faster
697 but at the expense of not being able to perform symbolic debugging.
698 This option is intended for use cases where symbolic debugging will
699 not be used, e.g., when you only need to dump the debuggee's core.
701 * GDB now uses the GNU MPFR library, if available, to emulate target
702 floating-point arithmetic during expression evaluation when the target
703 uses different floating-point formats than the host. At least version
704 3.1 of GNU MPFR is required.
706 * GDB now supports access to the guarded-storage-control registers and the
707 software-based guarded-storage broadcast control registers on IBM z14.
709 * On Unix systems, GDB now supports transmitting environment variables
710 that are to be set or unset to GDBserver. These variables will
711 affect the environment to be passed to the remote inferior.
713 To inform GDB of environment variables that are to be transmitted to
714 GDBserver, use the "set environment" command. Only user set
715 environment variables are sent to GDBserver.
717 To inform GDB of environment variables that are to be unset before
718 the remote inferior is started by the GDBserver, use the "unset
719 environment" command.
721 * Completion improvements
723 ** GDB can now complete function parameters in linespecs and
724 explicit locations without quoting. When setting breakpoints,
725 quoting around functions names to help with TAB-completion is
726 generally no longer necessary. For example, this now completes
729 (gdb) b function(in[TAB]
730 (gdb) b function(int)
732 Related, GDB is no longer confused with completing functions in
733 C++ anonymous namespaces:
736 (gdb) b (anonymous namespace)::[TAB][TAB]
737 (anonymous namespace)::a_function()
738 (anonymous namespace)::b_function()
740 ** GDB now has much improved linespec and explicit locations TAB
741 completion support, that better understands what you're
742 completing and offers better suggestions. For example, GDB no
743 longer offers data symbols as possible completions when you're
744 setting a breakpoint.
746 ** GDB now TAB-completes label symbol names.
748 ** The "complete" command now mimics TAB completion accurately.
750 * New command line options (gcore)
753 Dump all memory mappings.
755 * Breakpoints on C++ functions are now set on all scopes by default
757 By default, breakpoints on functions/methods are now interpreted as
758 specifying all functions with the given name ignoring missing
759 leading scopes (namespaces and classes).
761 For example, assuming a C++ program with symbols named:
766 both commands "break func()" and "break B::func()" set a breakpoint
769 You can use the new flag "-qualified" to override this. This makes
770 GDB interpret the specified function name as a complete
771 fully-qualified name instead. For example, using the same C++
772 program, the "break -q B::func" command sets a breakpoint on
773 "B::func", only. A parameter has been added to the Python
774 gdb.Breakpoint constructor to achieve the same result when creating
775 a breakpoint from Python.
777 * Breakpoints on functions marked with C++ ABI tags
779 GDB can now set breakpoints on functions marked with C++ ABI tags
780 (e.g., [abi:cxx11]). See here for a description of ABI tags:
781 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
783 Functions with a C++11 abi tag are demangled/displayed like this:
785 function[abi:cxx11](int)
788 You can now set a breakpoint on such functions simply as if they had
791 (gdb) b function(int)
793 Or if you need to disambiguate between tags, like:
795 (gdb) b function[abi:other_tag](int)
797 Tab completion was adjusted accordingly as well.
801 ** New events gdb.new_inferior, gdb.inferior_deleted, and
802 gdb.new_thread are emitted. See the manual for further
803 description of these.
805 ** A new function, "gdb.rbreak" has been added to the Python API.
806 This function allows the setting of a large number of breakpoints
807 via a regex pattern in Python. See the manual for further details.
809 ** Python breakpoints can now accept explicit locations. See the
810 manual for a further description of this feature.
813 * New features in the GDB remote stub, GDBserver
815 ** GDBserver is now able to start inferior processes with a
816 specified initial working directory.
818 The user can set the desired working directory to be used from
819 GDB using the new "set cwd" command.
821 ** New "--selftest" command line option runs some GDBserver self
822 tests. These self tests are disabled in releases.
824 ** On Unix systems, GDBserver now does globbing expansion and variable
825 substitution in inferior command line arguments.
827 This is done by starting inferiors using a shell, like GDB does.
828 See "set startup-with-shell" in the user manual for how to disable
829 this from GDB when using "target extended-remote". When using
830 "target remote", you can disable the startup with shell by using the
831 new "--no-startup-with-shell" GDBserver command line option.
833 ** On Unix systems, GDBserver now supports receiving environment
834 variables that are to be set or unset from GDB. These variables
835 will affect the environment to be passed to the inferior.
837 * When catching an Ada exception raised with a message, GDB now prints
838 the message in the catchpoint hit notification. In GDB/MI mode, that
839 information is provided as an extra field named "exception-message"
840 in the *stopped notification.
842 * Trait objects can now be inspected When debugging Rust code. This
843 requires compiler support which will appear in Rust 1.24.
847 QEnvironmentHexEncoded
848 Inform GDBserver of an environment variable that is to be passed to
849 the inferior when starting it.
852 Inform GDBserver of an environment variable that is to be unset
853 before starting the remote inferior.
856 Inform GDBserver that the environment should be reset (i.e.,
857 user-set environment variables should be unset).
860 Indicates whether the inferior must be started with a shell or not.
863 Tell GDBserver that the inferior to be started should use a specific
866 * The "maintenance print c-tdesc" command now takes an optional
867 argument which is the file name of XML target description.
869 * The "maintenance selftest" command now takes an optional argument to
870 filter the tests to be run.
872 * The "enable", and "disable" commands now accept a range of
873 breakpoint locations, e.g. "enable 1.3-5".
878 Set and show the current working directory for the inferior.
881 Set and show compilation command used for compiling and injecting code
882 with the 'compile' commands.
884 set debug separate-debug-file
885 show debug separate-debug-file
886 Control the display of debug output about separate debug file search.
888 set dump-excluded-mappings
889 show dump-excluded-mappings
890 Control whether mappings marked with the VM_DONTDUMP flag should be
891 dumped when generating a core file.
894 List the registered selftests.
897 Start the debugged program stopping at the first instruction.
900 Control display of debugging messages related to OpenRISC targets.
902 set|show print type nested-type-limit
903 Set and show the limit of nesting level for nested types that the
904 type printer will show.
906 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
909 * Safer/improved support for debugging with no debug info
911 GDB no longer assumes functions with no debug information return
914 This means that GDB now refuses to call such functions unless you
915 tell it the function's type, by either casting the call to the
916 declared return type, or by casting the function to a function
917 pointer of the right type, and calling that:
919 (gdb) p getenv ("PATH")
920 'getenv' has unknown return type; cast the call to its declared return type
921 (gdb) p (char *) getenv ("PATH")
922 $1 = 0x7fffffffe "/usr/local/bin:/"...
923 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
924 $2 = 0x7fffffffe "/usr/local/bin:/"...
926 Similarly, GDB no longer assumes that global variables with no debug
927 info have type 'int', and refuses to print the variable's value
928 unless you tell it the variable's type:
931 'var' has unknown type; cast it to its declared type
935 * New native configurations
937 FreeBSD/aarch64 aarch64*-*-freebsd*
938 FreeBSD/arm arm*-*-freebsd*
942 FreeBSD/aarch64 aarch64*-*-freebsd*
943 FreeBSD/arm arm*-*-freebsd*
944 OpenRISC ELF or1k*-*-elf
946 * Removed targets and native configurations
948 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
950 *** Changes in GDB 8.0
952 * GDB now supports access to the PKU register on GNU/Linux. The register is
953 added by the Memory Protection Keys for Userspace feature which will be
954 available in future Intel CPUs.
956 * GDB now supports C++11 rvalue references.
960 ** New functions to start, stop and access a running btrace recording.
961 ** Rvalue references are now supported in gdb.Type.
963 * GDB now supports recording and replaying rdrand and rdseed Intel 64
966 * Building GDB and GDBserver now requires a C++11 compiler.
968 For example, GCC 4.8 or later.
970 It is no longer possible to build GDB or GDBserver with a C
971 compiler. The --disable-build-with-cxx configure option has been
974 * Building GDB and GDBserver now requires GNU make >= 3.81.
976 It is no longer supported to build GDB or GDBserver with another
977 implementation of the make program or an earlier version of GNU make.
979 * Native debugging on MS-Windows supports command-line redirection
981 Command-line arguments used for starting programs on MS-Windows can
982 now include redirection symbols supported by native Windows shells,
983 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
984 as "run", "start", and "set args", as well as the corresponding MI
987 * Support for thread names on MS-Windows.
989 GDB now catches and handles the special exception that programs
990 running on MS-Windows use to assign names to threads in the
993 * Support for Java programs compiled with gcj has been removed.
995 * User commands now accept an unlimited number of arguments.
996 Previously, only up to 10 was accepted.
998 * The "eval" command now expands user-defined command arguments.
1000 This makes it easier to process a variable number of arguments:
1005 eval "print $arg%d", $i
1010 * Target descriptions can now describe registers for sparc32 and sparc64.
1012 * GDB now supports DWARF version 5 (debug information format).
1013 Its .debug_names index is not yet supported.
1015 * New native configurations
1017 FreeBSD/mips mips*-*-freebsd
1021 Synopsys ARC arc*-*-elf32
1022 FreeBSD/mips mips*-*-freebsd
1024 * Removed targets and native configurations
1026 Alpha running FreeBSD alpha*-*-freebsd*
1027 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1032 Erases all the flash memory regions reported by the target.
1034 maint print arc arc-instruction address
1035 Print internal disassembler information about instruction at a given address.
1039 set disassembler-options
1040 show disassembler-options
1041 Controls the passing of target specific information to the disassembler.
1042 If it is necessary to specify more than one disassembler option then
1043 multiple options can be placed together into a comma separated list.
1044 The default value is the empty string. Currently, the only supported
1045 targets are ARM, PowerPC and S/390.
1050 Erases all the flash memory regions reported by the target. This is
1051 equivalent to the CLI command flash-erase.
1053 -file-list-shared-libraries
1054 List the shared libraries in the program. This is
1055 equivalent to the CLI command "info shared".
1058 Catchpoints stopping the program when Ada exceptions are
1059 handled. This is equivalent to the CLI command "catch handlers".
1061 *** Changes in GDB 7.12
1063 * GDB and GDBserver now build with a C++ compiler by default.
1065 The --enable-build-with-cxx configure option is now enabled by
1066 default. One must now explicitly configure with
1067 --disable-build-with-cxx in order to build with a C compiler. This
1068 option will be removed in a future release.
1070 * GDBserver now supports recording btrace without maintaining an active
1073 * GDB now supports a negative repeat count in the 'x' command to examine
1074 memory backward from the given address. For example:
1077 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1078 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1079 (gdb) x/-5i 0x0000000000400580
1080 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1081 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1082 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1083 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1084 0x40057b <main(int, char**)+25>:
1085 callq 0x400536 <Func1(int, char const*)>
1087 * Fortran: Support structures with fields of dynamic types and
1088 arrays of dynamic types.
1090 * The symbol dumping maintenance commands have new syntax.
1091 maint print symbols [-pc address] [--] [filename]
1092 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1093 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1094 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1095 maint print msymbols [-objfile objfile] [--] [filename]
1097 * GDB now supports multibit bitfields and enums in target register
1100 * New Python-based convenience function $_as_string(val), which returns
1101 the textual representation of a value. This function is especially
1102 useful to obtain the text label of an enum value.
1104 * Intel MPX bound violation handling.
1106 Segmentation faults caused by a Intel MPX boundary violation
1107 now display the kind of violation (upper or lower), the memory
1108 address accessed and the memory bounds, along with the usual
1109 signal received and code location.
1113 Program received signal SIGSEGV, Segmentation fault
1114 Upper bound violation while accessing address 0x7fffffffc3b3
1115 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1116 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1118 * Rust language support.
1119 GDB now supports debugging programs written in the Rust programming
1120 language. See https://www.rust-lang.org/ for more information about
1123 * Support for running interpreters on specified input/output devices
1125 GDB now supports a new mechanism that allows frontends to provide
1126 fully featured GDB console views, as a better alternative to
1127 building such views on top of the "-interpreter-exec console"
1128 command. See the new "new-ui" command below. With that command,
1129 frontends can now start GDB in the traditional command-line mode
1130 running in an embedded terminal emulator widget, and create a
1131 separate MI interpreter running on a specified i/o device. In this
1132 way, GDB handles line editing, history, tab completion, etc. in the
1133 console all by itself, and the GUI uses the separate MI interpreter
1134 for its own control and synchronization, invisible to the command
1137 * The "catch syscall" command catches groups of related syscalls.
1139 The "catch syscall" command now supports catching a group of related
1140 syscalls using the 'group:' or 'g:' prefix.
1145 skip -gfile file-glob-pattern
1146 skip -function function
1147 skip -rfunction regular-expression
1148 A generalized form of the skip command, with new support for
1149 glob-style file names and regular expressions for function names.
1150 Additionally, a file spec and a function spec may now be combined.
1152 maint info line-table REGEXP
1153 Display the contents of GDB's internal line table data struture.
1156 Run any GDB unit tests that were compiled in.
1159 Start a new user interface instance running INTERP as interpreter,
1160 using the TTY file for input/output.
1164 ** gdb.Breakpoint objects have a new attribute "pending", which
1165 indicates whether the breakpoint is pending.
1166 ** Three new breakpoint-related events have been added:
1167 gdb.breakpoint_created, gdb.breakpoint_modified, and
1168 gdb.breakpoint_deleted.
1170 signal-event EVENTID
1171 Signal ("set") the given MS-Windows event object. This is used in
1172 conjunction with the Windows JIT debugging (AeDebug) support, where
1173 the OS suspends a crashing process until a debugger can attach to
1174 it. Resuming the crashing process, in order to debug it, is done by
1175 signalling an event.
1177 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1178 was added in GDBserver, including JIT compiling fast tracepoint's
1179 conditional expression bytecode into native code.
1181 * Support for various remote target protocols and ROM monitors has
1184 target m32rsdi Remote M32R debugging over SDI
1185 target mips MIPS remote debugging protocol
1186 target pmon PMON ROM monitor
1187 target ddb NEC's DDB variant of PMON for Vr4300
1188 target rockhopper NEC RockHopper variant of PMON
1189 target lsi LSI variant of PMO
1191 * Support for tracepoints and fast tracepoints on powerpc-linux,
1192 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1193 including JIT compiling fast tracepoint's conditional expression
1194 bytecode into native code.
1196 * MI async record =record-started now includes the method and format used for
1197 recording. For example:
1199 =record-started,thread-group="i1",method="btrace",format="bts"
1201 * MI async record =thread-selected now includes the frame field. For example:
1203 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1207 Andes NDS32 nds32*-*-elf
1209 *** Changes in GDB 7.11
1211 * GDB now supports debugging kernel-based threads on FreeBSD.
1213 * Per-inferior thread numbers
1215 Thread numbers are now per inferior instead of global. If you're
1216 debugging multiple inferiors, GDB displays thread IDs using a
1217 qualified INF_NUM.THR_NUM form. For example:
1221 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1222 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1223 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1224 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1226 As consequence, thread numbers as visible in the $_thread
1227 convenience variable and in Python's InferiorThread.num attribute
1228 are no longer unique between inferiors.
1230 GDB now maintains a second thread ID per thread, referred to as the
1231 global thread ID, which is the new equivalent of thread numbers in
1232 previous releases. See also $_gthread below.
1234 For backwards compatibility, MI's thread IDs always refer to global
1237 * Commands that accept thread IDs now accept the qualified
1238 INF_NUM.THR_NUM form as well. For example:
1241 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1244 * In commands that accept a list of thread IDs, you can now refer to
1245 all threads of an inferior using a star wildcard. GDB accepts
1246 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1247 refer to all threads of the current inferior. For example, "info
1250 * You can use "info threads -gid" to display the global thread ID of
1253 * The new convenience variable $_gthread holds the global number of
1256 * The new convenience variable $_inferior holds the number of the
1259 * GDB now displays the ID and name of the thread that hit a breakpoint
1260 or received a signal, if your program is multi-threaded. For
1263 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1264 Thread 1 "main" received signal SIGINT, Interrupt.
1266 * Record btrace now supports non-stop mode.
1268 * Support for tracepoints on aarch64-linux was added in GDBserver.
1270 * The 'record instruction-history' command now indicates speculative execution
1271 when using the Intel Processor Trace recording format.
1273 * GDB now allows users to specify explicit locations, bypassing
1274 the linespec parser. This feature is also available to GDB/MI
1277 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1278 GDB now is able to debug both AArch64 applications and ARM applications
1281 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1282 including JIT compiling fast tracepoint's conditional expression bytecode
1285 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1287 * "info threads", "info inferiors", "info display", "info checkpoints"
1288 and "maint info program-spaces" now list the corresponding items in
1289 ascending ID order, for consistency with all other "info" commands.
1291 * In Ada, the overloads selection menu has been enhanced to display the
1292 parameter types and the return types for the matching overloaded subprograms.
1296 maint set target-non-stop (on|off|auto)
1297 maint show target-non-stop
1298 Control whether GDB targets always operate in non-stop mode even if
1299 "set non-stop" is "off". The default is "auto", meaning non-stop
1300 mode is enabled if supported by the target.
1302 maint set bfd-sharing
1303 maint show bfd-sharing
1304 Control the reuse of bfd objects.
1307 show debug bfd-cache
1308 Control display of debugging info regarding bfd caching.
1312 Control display of debugging info regarding FreeBSD threads.
1314 set remote multiprocess-extensions-packet
1315 show remote multiprocess-extensions-packet
1316 Set/show the use of the remote protocol multiprocess extensions.
1318 set remote thread-events
1319 show remote thread-events
1320 Set/show the use of thread create/exit events.
1322 set ada print-signatures on|off
1323 show ada print-signatures"
1324 Control whether parameter types and return types are displayed in overloads
1325 selection menus. It is activaled (@code{on}) by default.
1329 Controls the maximum size of memory, in bytes, that GDB will
1330 allocate for value contents. Prevents incorrect programs from
1331 causing GDB to allocate overly large buffers. Default is 64k.
1333 * The "disassemble" command accepts a new modifier: /s.
1334 It prints mixed source+disassembly like /m with two differences:
1335 - disassembled instructions are now printed in program order, and
1336 - and source for all relevant files is now printed.
1337 The "/m" option is now considered deprecated: its "source-centric"
1338 output hasn't proved useful in practice.
1340 * The "record instruction-history" command accepts a new modifier: /s.
1341 It behaves exactly like /m and prints mixed source+disassembly.
1343 * The "set scheduler-locking" command supports a new mode "replay".
1344 It behaves like "off" in record mode and like "on" in replay mode.
1346 * Support for various ROM monitors has been removed:
1348 target dbug dBUG ROM monitor for Motorola ColdFire
1349 target picobug Motorola picobug monitor
1350 target dink32 DINK32 ROM monitor for PowerPC
1351 target m32r Renesas M32R/D ROM monitor
1352 target mon2000 mon2000 ROM monitor
1353 target ppcbug PPCBUG ROM monitor for PowerPC
1355 * Support for reading/writing memory and extracting values on architectures
1356 whose memory is addressable in units of any integral multiple of 8 bits.
1359 Allows to break when an Ada exception is handled.
1361 * New remote packets
1364 Indicates that an exec system call was executed.
1366 exec-events feature in qSupported
1367 The qSupported packet allows GDB to request support for exec
1368 events using the new 'gdbfeature' exec-event, and the qSupported
1369 response can contain the corresponding 'stubfeature'. Set and
1370 show commands can be used to display whether these features are enabled.
1373 Equivalent to interrupting with the ^C character, but works in
1376 thread created stop reason (T05 create:...)
1377 Indicates that the thread was just created and is stopped at entry.
1379 thread exit stop reply (w exitcode;tid)
1380 Indicates that the thread has terminated.
1383 Enables/disables thread create and exit event reporting. For
1384 example, this is used in non-stop mode when GDB stops a set of
1385 threads and synchronously waits for the their corresponding stop
1386 replies. Without exit events, if one of the threads exits, GDB
1387 would hang forever not knowing that it should no longer expect a
1388 stop for that same thread.
1391 Indicates that there are no resumed threads left in the target (all
1392 threads are stopped). The remote stub reports support for this stop
1393 reply to GDB's qSupported query.
1396 Enables/disables catching syscalls from the inferior process.
1397 The remote stub reports support for this packet to GDB's qSupported query.
1399 syscall_entry stop reason
1400 Indicates that a syscall was just called.
1402 syscall_return stop reason
1403 Indicates that a syscall just returned.
1405 * Extended-remote exec events
1407 ** GDB now has support for exec events on extended-remote Linux targets.
1408 For such targets with Linux kernels 2.5.46 and later, this enables
1409 follow-exec-mode and exec catchpoints.
1411 set remote exec-event-feature-packet
1412 show remote exec-event-feature-packet
1413 Set/show the use of the remote exec event feature.
1415 * Thread names in remote protocol
1417 The reply to qXfer:threads:read may now include a name attribute for each
1420 * Target remote mode fork and exec events
1422 ** GDB now has support for fork and exec events on target remote mode
1423 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1424 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1425 fork and exec catchpoints.
1427 * Remote syscall events
1429 ** GDB now has support for catch syscall on remote Linux targets,
1430 currently enabled on x86/x86_64 architectures.
1432 set remote catch-syscall-packet
1433 show remote catch-syscall-packet
1434 Set/show the use of the remote catch syscall feature.
1438 ** The -var-set-format command now accepts the zero-hexadecimal
1439 format. It outputs data in hexadecimal format with zero-padding on the
1444 ** gdb.InferiorThread objects have a new attribute "global_num",
1445 which refers to the thread's global thread ID. The existing
1446 "num" attribute now refers to the thread's per-inferior number.
1447 See "Per-inferior thread numbers" above.
1448 ** gdb.InferiorThread objects have a new attribute "inferior", which
1449 is the Inferior object the thread belongs to.
1451 *** Changes in GDB 7.10
1453 * Support for process record-replay and reverse debugging on aarch64*-linux*
1454 targets has been added. GDB now supports recording of A64 instruction set
1455 including advance SIMD instructions.
1457 * Support for Sun's version of the "stabs" debug file format has been removed.
1459 * GDB now honors the content of the file /proc/PID/coredump_filter
1460 (PID is the process ID) on GNU/Linux systems. This file can be used
1461 to specify the types of memory mappings that will be included in a
1462 corefile. For more information, please refer to the manual page of
1463 "core(5)". GDB also has a new command: "set use-coredump-filter
1464 on|off". It allows to set whether GDB will read the content of the
1465 /proc/PID/coredump_filter file when generating a corefile.
1467 * The "info os" command on GNU/Linux can now display information on
1469 "info os cpus" Listing of all cpus/cores on the system
1471 * GDB has two new commands: "set serial parity odd|even|none" and
1472 "show serial parity". These allows to set or show parity for the
1475 * The "info source" command now displays the producer string if it was
1476 present in the debug info. This typically includes the compiler version
1477 and may include things like its command line arguments.
1479 * The "info dll", an alias of the "info sharedlibrary" command,
1480 is now available on all platforms.
1482 * Directory names supplied to the "set sysroot" commands may be
1483 prefixed with "target:" to tell GDB to access shared libraries from
1484 the target system, be it local or remote. This replaces the prefix
1485 "remote:". The default sysroot has been changed from "" to
1486 "target:". "remote:" is automatically converted to "target:" for
1487 backward compatibility.
1489 * The system root specified by "set sysroot" will be prepended to the
1490 filename of the main executable (if reported to GDB as absolute by
1491 the operating system) when starting processes remotely, and when
1492 attaching to already-running local or remote processes.
1494 * GDB now supports automatic location and retrieval of executable
1495 files from remote targets. Remote debugging can now be initiated
1496 using only a "target remote" or "target extended-remote" command
1497 (no "set sysroot" or "file" commands are required). See "New remote
1500 * The "dump" command now supports verilog hex format.
1502 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1504 * On GNU/Linux, GDB and gdbserver are now able to access executable
1505 and shared library files without a "set sysroot" command when
1506 attaching to processes running in different mount namespaces from
1507 the debugger. This makes it possible to attach to processes in
1508 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1509 See "New remote packets" below.
1511 * The "tui reg" command now provides completion for all of the
1512 available register groups, including target specific groups.
1514 * The HISTSIZE environment variable is no longer read when determining
1515 the size of GDB's command history. GDB now instead reads the dedicated
1516 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1517 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1522 ** Memory ports can now be unbuffered.
1526 ** gdb.Objfile objects have a new attribute "username",
1527 which is the name of the objfile as specified by the user,
1528 without, for example, resolving symlinks.
1529 ** You can now write frame unwinders in Python.
1530 ** gdb.Type objects have a new method "optimized_out",
1531 returning optimized out gdb.Value instance of this type.
1532 ** gdb.Value objects have new methods "reference_value" and
1533 "const_value" which return a reference to the value and a
1534 "const" version of the value respectively.
1538 maint print symbol-cache
1539 Print the contents of the symbol cache.
1541 maint print symbol-cache-statistics
1542 Print statistics of symbol cache usage.
1544 maint flush-symbol-cache
1545 Flush the contents of the symbol cache.
1549 Start branch trace recording using Branch Trace Store (BTS) format.
1552 Evaluate expression by using the compiler and print result.
1556 Explicit commands for enabling and disabling tui mode.
1559 set mpx bound on i386 and amd64
1560 Support for bound table investigation on Intel MPX enabled applications.
1564 Start branch trace recording using Intel Processor Trace format.
1567 Print information about branch tracing internals.
1569 maint btrace packet-history
1570 Print the raw branch tracing data.
1572 maint btrace clear-packet-history
1573 Discard the stored raw branch tracing data.
1576 Discard all branch tracing data. It will be fetched and processed
1577 anew by the next "record" command.
1582 Renamed from "set debug dwarf2-die".
1583 show debug dwarf-die
1584 Renamed from "show debug dwarf2-die".
1586 set debug dwarf-read
1587 Renamed from "set debug dwarf2-read".
1588 show debug dwarf-read
1589 Renamed from "show debug dwarf2-read".
1591 maint set dwarf always-disassemble
1592 Renamed from "maint set dwarf2 always-disassemble".
1593 maint show dwarf always-disassemble
1594 Renamed from "maint show dwarf2 always-disassemble".
1596 maint set dwarf max-cache-age
1597 Renamed from "maint set dwarf2 max-cache-age".
1598 maint show dwarf max-cache-age
1599 Renamed from "maint show dwarf2 max-cache-age".
1601 set debug dwarf-line
1602 show debug dwarf-line
1603 Control display of debugging info regarding DWARF line processing.
1606 show max-completions
1607 Set the maximum number of candidates to be considered during
1608 completion. The default value is 200. This limit allows GDB
1609 to avoid generating large completion lists, the computation of
1610 which can cause the debugger to become temporarily unresponsive.
1612 set history remove-duplicates
1613 show history remove-duplicates
1614 Control the removal of duplicate history entries.
1616 maint set symbol-cache-size
1617 maint show symbol-cache-size
1618 Control the size of the symbol cache.
1620 set|show record btrace bts buffer-size
1621 Set and show the size of the ring buffer used for branch tracing in
1623 The obtained size may differ from the requested size. Use "info
1624 record" to see the obtained buffer size.
1626 set debug linux-namespaces
1627 show debug linux-namespaces
1628 Control display of debugging info regarding Linux namespaces.
1630 set|show record btrace pt buffer-size
1631 Set and show the size of the ring buffer used for branch tracing in
1632 Intel Processor Trace format.
1633 The obtained size may differ from the requested size. Use "info
1634 record" to see the obtained buffer size.
1636 maint set|show btrace pt skip-pad
1637 Set and show whether PAD packets are skipped when computing the
1640 * The command 'thread apply all' can now support new option '-ascending'
1641 to call its specified command for all threads in ascending order.
1643 * Python/Guile scripting
1645 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1646 special section named `.debug_gdb_scripts'.
1648 * New remote packets
1650 qXfer:btrace-conf:read
1651 Return the branch trace configuration for the current thread.
1653 Qbtrace-conf:bts:size
1654 Set the requested ring buffer size for branch tracing in BTS format.
1657 Enable Intel Procesor Trace-based branch tracing for the current
1658 process. The remote stub reports support for this packet to GDB's
1661 Qbtrace-conf:pt:size
1662 Set the requested ring buffer size for branch tracing in Intel Processor
1666 Indicates a memory breakpoint instruction was executed, irrespective
1667 of whether it was GDB that planted the breakpoint or the breakpoint
1668 is hardcoded in the program. This is required for correct non-stop
1672 Indicates the target stopped for a hardware breakpoint. This is
1673 required for correct non-stop mode operation.
1676 Return information about files on the remote system.
1678 qXfer:exec-file:read
1679 Return the full absolute name of the file that was executed to
1680 create a process running on the remote system.
1683 Select the filesystem on which vFile: operations with filename
1684 arguments will operate. This is required for GDB to be able to
1685 access files on remote targets where the remote stub does not
1686 share a common filesystem with the inferior(s).
1689 Indicates that a fork system call was executed.
1692 Indicates that a vfork system call was executed.
1694 vforkdone stop reason
1695 Indicates that a vfork child of the specified process has executed
1696 an exec or exit, allowing the vfork parent to resume execution.
1698 fork-events and vfork-events features in qSupported
1699 The qSupported packet allows GDB to request support for fork and
1700 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1701 and the qSupported response can contain the corresponding
1702 'stubfeatures'. Set and show commands can be used to display
1703 whether these features are enabled.
1705 * Extended-remote fork events
1707 ** GDB now has support for fork events on extended-remote Linux
1708 targets. For targets with Linux kernels 2.5.60 and later, this
1709 enables follow-fork-mode and detach-on-fork for both fork and
1710 vfork, as well as fork and vfork catchpoints.
1712 * The info record command now shows the recording format and the
1713 branch tracing configuration for the current thread when using
1714 the btrace record target.
1715 For the BTS format, it shows the ring buffer size.
1717 * GDB now has support for DTrace USDT (Userland Static Defined
1718 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1720 * GDB now supports access to vector registers on S/390 GNU/Linux
1723 * Removed command line options
1725 -xdb HP-UX XDB compatibility mode.
1727 * Removed targets and native configurations
1729 HP/PA running HP-UX hppa*-*-hpux*
1730 Itanium running HP-UX ia64-*-hpux*
1732 * New configure options
1735 This configure option allows the user to build GDB with support for
1736 Intel Processor Trace (default: auto). This requires libipt.
1738 --with-libipt-prefix=PATH
1739 Specify the path to the version of libipt that GDB should use.
1740 $PATH/include should contain the intel-pt.h header and
1741 $PATH/lib should contain the libipt.so library.
1743 *** Changes in GDB 7.9.1
1747 ** Xmethods can now specify a result type.
1749 *** Changes in GDB 7.9
1751 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1755 ** You can now access frame registers from Python scripts.
1756 ** New attribute 'producer' for gdb.Symtab objects.
1757 ** gdb.Objfile objects have a new attribute "progspace",
1758 which is the gdb.Progspace object of the containing program space.
1759 ** gdb.Objfile objects have a new attribute "owner".
1760 ** gdb.Objfile objects have a new attribute "build_id",
1761 which is the build ID generated when the file was built.
1762 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1763 ** A new event "gdb.clear_objfiles" has been added, triggered when
1764 selecting a new file to debug.
1765 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1766 ** New function gdb.lookup_objfile.
1768 New events which are triggered when GDB modifies the state of the
1771 ** gdb.events.inferior_call_pre: Function call is about to be made.
1772 ** gdb.events.inferior_call_post: Function call has just been made.
1773 ** gdb.events.memory_changed: A memory location has been altered.
1774 ** gdb.events.register_changed: A register has been altered.
1776 * New Python-based convenience functions:
1778 ** $_caller_is(name [, number_of_frames])
1779 ** $_caller_matches(regexp [, number_of_frames])
1780 ** $_any_caller_is(name [, number_of_frames])
1781 ** $_any_caller_matches(regexp [, number_of_frames])
1783 * GDB now supports the compilation and injection of source code into
1784 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1785 to compile the source code to object code, and if successful, inject
1786 and execute that code within the current context of the inferior.
1787 Currently the C language is supported. The commands used to
1788 interface with this new feature are:
1790 compile code [-raw|-r] [--] [source code]
1791 compile file [-raw|-r] filename
1795 demangle [-l language] [--] name
1796 Demangle "name" in the specified language, or the current language
1797 if elided. This command is renamed from the "maint demangle" command.
1798 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1799 as "maint demangler-warning".
1801 queue-signal signal-name-or-number
1802 Queue a signal to be delivered to the thread when it is resumed.
1804 add-auto-load-scripts-directory directory
1805 Add entries to the list of directories from which to load auto-loaded
1808 maint print user-registers
1809 List all currently available "user" registers.
1811 compile code [-r|-raw] [--] [source code]
1812 Compile, inject, and execute in the inferior the executable object
1813 code produced by compiling the provided source code.
1815 compile file [-r|-raw] filename
1816 Compile and inject into the inferior the executable object code
1817 produced by compiling the source code stored in the filename
1820 * On resume, GDB now always passes the signal the program had stopped
1821 for to the thread the signal was sent to, even if the user changed
1822 threads before resuming. Previously GDB would often (but not
1823 always) deliver the signal to the thread that happens to be current
1826 * Conversely, the "signal" command now consistently delivers the
1827 requested signal to the current thread. GDB now asks for
1828 confirmation if the program had stopped for a signal and the user
1829 switched threads meanwhile.
1831 * "breakpoint always-inserted" modes "off" and "auto" merged.
1833 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1834 won't remove breakpoints from the target until all threads stop,
1835 even in non-stop mode. The "auto" mode has been removed, and "off"
1836 is now the default mode.
1840 set debug symbol-lookup
1841 show debug symbol-lookup
1842 Control display of debugging info regarding symbol lookup.
1846 ** The -list-thread-groups command outputs an exit-code field for
1847 inferiors that have exited.
1851 MIPS SDE mips*-sde*-elf*
1855 Support for these obsolete configurations has been removed.
1857 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1858 SGI Irix-5.x mips-*-irix5*
1859 SGI Irix-6.x mips-*-irix6*
1860 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1861 VAX running Ultrix vax-*-ultrix*
1863 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1864 and "assf"), have been removed. Use the "sharedlibrary" command, or
1865 its alias "share", instead.
1867 *** Changes in GDB 7.8
1869 * New command line options
1872 This is an alias for the --data-directory option.
1874 * GDB supports printing and modifying of variable length automatic arrays
1875 as specified in ISO C99.
1877 * The ARM simulator now supports instruction level tracing
1878 with or without disassembly.
1882 GDB now has support for scripting using Guile. Whether this is
1883 available is determined at configure time.
1884 Guile version 2.0 or greater is required.
1885 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1887 * New commands (for set/show, see "New options" below)
1891 Invoke CODE by passing it to the Guile interpreter.
1895 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1897 info auto-load guile-scripts [regexp]
1898 Print the list of automatically loaded Guile scripts.
1900 * The source command is now capable of sourcing Guile scripts.
1901 This feature is dependent on the debugger being built with Guile support.
1905 set print symbol-loading (off|brief|full)
1906 show print symbol-loading
1907 Control whether to print informational messages when loading symbol
1908 information for a file. The default is "full", but when debugging
1909 programs with large numbers of shared libraries the amount of output
1910 becomes less useful.
1912 set guile print-stack (none|message|full)
1913 show guile print-stack
1914 Show a stack trace when an error is encountered in a Guile script.
1916 set auto-load guile-scripts (on|off)
1917 show auto-load guile-scripts
1918 Control auto-loading of Guile script files.
1920 maint ada set ignore-descriptive-types (on|off)
1921 maint ada show ignore-descriptive-types
1922 Control whether the debugger should ignore descriptive types in Ada
1923 programs. The default is not to ignore the descriptive types. See
1924 the user manual for more details on descriptive types and the intended
1925 usage of this option.
1927 set auto-connect-native-target
1929 Control whether GDB is allowed to automatically connect to the
1930 native target for the run, attach, etc. commands when not connected
1931 to any target yet. See also "target native" below.
1933 set record btrace replay-memory-access (read-only|read-write)
1934 show record btrace replay-memory-access
1935 Control what memory accesses are allowed during replay.
1937 maint set target-async (on|off)
1938 maint show target-async
1939 This controls whether GDB targets operate in synchronous or
1940 asynchronous mode. Normally the default is asynchronous, if it is
1941 available; but this can be changed to more easily debug problems
1942 occurring only in synchronous mode.
1944 set mi-async (on|off)
1946 Control whether MI asynchronous mode is preferred. This supersedes
1947 "set target-async" of previous GDB versions.
1949 * "set target-async" is deprecated as a CLI option and is now an alias
1950 for "set mi-async" (only puts MI into async mode).
1952 * Background execution commands (e.g., "c&", "s&", etc.) are now
1953 possible ``out of the box'' if the target supports them. Previously
1954 the user would need to explicitly enable the possibility with the
1955 "set target-async on" command.
1957 * New features in the GDB remote stub, GDBserver
1959 ** New option --debug-format=option1[,option2,...] allows one to add
1960 additional text to each output. At present only timestamps
1961 are supported: --debug-format=timestamps.
1962 Timestamps can also be turned on with the
1963 "monitor set debug-format timestamps" command from GDB.
1965 * The 'record instruction-history' command now starts counting instructions
1966 at one. This also affects the instruction ranges reported by the
1967 'record function-call-history' command when given the /i modifier.
1969 * The command 'record function-call-history' supports a new modifier '/c' to
1970 indent the function names based on their call stack depth.
1971 The fields for the '/i' and '/l' modifier have been reordered.
1972 The source line range is now prefixed with 'at'.
1973 The instruction range is now prefixed with 'inst'.
1974 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1975 "record instruction-history" and "list" commands.
1977 * The ranges given as arguments to the 'record function-call-history' and
1978 'record instruction-history' commands are now inclusive.
1980 * The btrace record target now supports the 'record goto' command.
1981 For locations inside the execution trace, the back trace is computed
1982 based on the information stored in the execution trace.
1984 * The btrace record target supports limited reverse execution and replay.
1985 The target does not record data and therefore does not allow reading
1986 memory or registers.
1988 * The "catch syscall" command now works on s390*-linux* targets.
1990 * The "compare-sections" command is no longer specific to target
1991 remote. It now works with all targets.
1993 * All native targets are now consistently called "native".
1994 Consequently, the "target child", "target GNU", "target djgpp",
1995 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1996 commands have been replaced with "target native". The QNX/NTO port
1997 leaves the "procfs" target in place and adds a "native" target for
1998 consistency with other ports. The impact on users should be minimal
1999 as these commands previously either throwed an error, or were
2000 no-ops. The target's name is visible in the output of the following
2001 commands: "help target", "info target", "info files", "maint print
2004 * The "target native" command now connects to the native target. This
2005 can be used to launch native programs even when "set
2006 auto-connect-native-target" is set to off.
2008 * GDB now supports access to Intel MPX registers on GNU/Linux.
2010 * Support for Intel AVX-512 registers on GNU/Linux.
2011 Support displaying and modifying Intel AVX-512 registers
2012 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2014 * New remote packets
2016 qXfer:btrace:read's annex
2017 The qXfer:btrace:read packet supports a new annex 'delta' to read
2018 branch trace incrementally.
2022 ** Valid Python operations on gdb.Value objects representing
2023 structs/classes invoke the corresponding overloaded operators if
2025 ** New `Xmethods' feature in the Python API. Xmethods are
2026 additional methods or replacements for existing methods of a C++
2027 class. This feature is useful for those cases where a method
2028 defined in C++ source code could be inlined or optimized out by
2029 the compiler, making it unavailable to GDB.
2032 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2034 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2035 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2036 its alias "share", instead.
2038 * The commands "set remotebaud" and "show remotebaud" are no longer
2039 supported. Use "set serial baud" and "show serial baud" (respectively)
2044 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2045 target-async". The latter is left as a deprecated alias of the
2046 former for backward compatibility. If the target supports it,
2047 CLI background execution commands are now always possible by
2048 default, independently of whether the frontend stated a
2049 preference for asynchronous execution with "-gdb-set mi-async".
2050 Previously "-gdb-set target-async off" affected both MI execution
2051 commands and CLI execution commands.
2053 *** Changes in GDB 7.7
2055 * Improved support for process record-replay and reverse debugging on
2056 arm*-linux* targets. Support for thumb32 and syscall instruction
2057 recording has been added.
2059 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2061 * GDB now supports Fission DWP file format version 2.
2062 http://gcc.gnu.org/wiki/DebugFission
2064 * New convenience function "$_isvoid", to check whether an expression
2065 is void. A void expression is an expression where the type of the
2066 result is "void". For example, some convenience variables may be
2067 "void" when evaluated (e.g., "$_exitcode" before the execution of
2068 the program being debugged; or an undefined convenience variable).
2069 Another example, when calling a function whose return type is
2072 * The "maintenance print objfiles" command now takes an optional regexp.
2074 * The "catch syscall" command now works on arm*-linux* targets.
2076 * GDB now consistently shows "<not saved>" when printing values of
2077 registers the debug info indicates have not been saved in the frame
2078 and there's nowhere to retrieve them from
2079 (callee-saved/call-clobbered registers):
2084 (gdb) info registers rax
2087 Before, the former would print "<optimized out>", and the latter
2088 "*value not available*".
2090 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2095 ** Frame filters and frame decorators have been added.
2096 ** Temporary breakpoints are now supported.
2097 ** Line tables representation has been added.
2098 ** New attribute 'parent_type' for gdb.Field objects.
2099 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2100 ** New attribute 'name' for gdb.Type objects.
2104 Nios II ELF nios2*-*-elf
2105 Nios II GNU/Linux nios2*-*-linux
2106 Texas Instruments MSP430 msp430*-*-elf
2108 * Removed native configurations
2110 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2111 been removed. ELF variants of these configurations are kept supported.
2113 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2114 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2115 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2116 i[34567]86-*-openbsd3.[0-3]
2117 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2118 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2119 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2123 Like "catch throw", but catches a re-thrown exception.
2124 maint check-psymtabs
2125 Renamed from old "maint check-symtabs".
2127 Perform consistency checks on symtabs.
2128 maint expand-symtabs
2129 Expand symtabs matching an optional regexp.
2132 Display the details of GDB configure-time options.
2134 maint set|show per-command
2135 maint set|show per-command space
2136 maint set|show per-command time
2137 maint set|show per-command symtab
2138 Enable display of per-command gdb resource usage.
2140 remove-symbol-file FILENAME
2141 remove-symbol-file -a ADDRESS
2142 Remove a symbol file added via add-symbol-file. The file to remove
2143 can be identified by its filename or by an address that lies within
2144 the boundaries of this symbol file in memory.
2147 info exceptions REGEXP
2148 Display the list of Ada exceptions defined in the program being
2149 debugged. If provided, only the exceptions whose names match REGEXP
2154 set debug symfile off|on
2156 Control display of debugging info regarding reading symbol files and
2157 symbol tables within those files
2159 set print raw frame-arguments
2160 show print raw frame-arguments
2161 Set/show whether to print frame arguments in raw mode,
2162 disregarding any defined pretty-printers.
2164 set remote trace-status-packet
2165 show remote trace-status-packet
2166 Set/show the use of remote protocol qTStatus packet.
2170 Control display of debugging messages related to Nios II targets.
2174 Control whether target-assisted range stepping is enabled.
2176 set startup-with-shell
2177 show startup-with-shell
2178 Specifies whether Unix child processes are started via a shell or
2183 Use the target memory cache for accesses to the code segment. This
2184 improves performance of remote debugging (particularly disassembly).
2186 * You can now use a literal value 'unlimited' for options that
2187 interpret 0 or -1 as meaning "unlimited". E.g., "set
2188 trace-buffer-size unlimited" is now an alias for "set
2189 trace-buffer-size -1" and "set height unlimited" is now an alias for
2192 * The "set debug symtab-create" debugging option of GDB has been changed to
2193 accept a verbosity level. 0 means "off", 1 provides basic debugging
2194 output, and values of 2 or greater provides more verbose output.
2196 * New command-line options
2198 Display the details of GDB configure-time options.
2200 * The command 'tsave' can now support new option '-ctf' to save trace
2201 buffer in Common Trace Format.
2203 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2206 * GDB now implements the the C++ 'typeid' operator.
2208 * The new convenience variable $_exception holds the exception being
2209 thrown or caught at an exception-related catchpoint.
2211 * The exception-related catchpoints, like "catch throw", now accept a
2212 regular expression which can be used to filter exceptions by type.
2214 * The new convenience variable $_exitsignal is automatically set to
2215 the terminating signal number when the program being debugged dies
2216 due to an uncaught signal.
2220 ** All MI commands now accept an optional "--language" option.
2221 Support for this feature can be verified by using the "-list-features"
2222 command, which should contain "language-option".
2224 ** The new command -info-gdb-mi-command allows the user to determine
2225 whether a GDB/MI command is supported or not.
2227 ** The "^error" result record returned when trying to execute an undefined
2228 GDB/MI command now provides a variable named "code" whose content is the
2229 "undefined-command" error code. Support for this feature can be verified
2230 by using the "-list-features" command, which should contain
2231 "undefined-command-error-code".
2233 ** The -trace-save MI command can optionally save trace buffer in Common
2236 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2238 ** The command -data-list-register-values now accepts an optional
2239 "--skip-unavailable" option. When used, only the available registers
2242 ** The new command -trace-frame-collected dumps collected variables,
2243 computed expressions, tvars, memory and registers in a traceframe.
2245 ** The commands -stack-list-locals, -stack-list-arguments and
2246 -stack-list-variables now accept an option "--skip-unavailable".
2247 When used, only the available locals or arguments are displayed.
2249 ** The -exec-run command now accepts an optional "--start" option.
2250 When used, the command follows the same semantics as the "start"
2251 command, stopping the program's execution at the start of its
2252 main subprogram. Support for this feature can be verified using
2253 the "-list-features" command, which should contain
2254 "exec-run-start-option".
2256 ** The new commands -catch-assert and -catch-exceptions insert
2257 catchpoints stopping the program when Ada exceptions are raised.
2259 ** The new command -info-ada-exceptions provides the equivalent of
2260 the new "info exceptions" command.
2262 * New system-wide configuration scripts
2263 A GDB installation now provides scripts suitable for use as system-wide
2264 configuration scripts for the following systems:
2268 * GDB now supports target-assigned range stepping with remote targets.
2269 This improves the performance of stepping source lines by reducing
2270 the number of control packets from/to GDB. See "New remote packets"
2273 * GDB now understands the element 'tvar' in the XML traceframe info.
2274 It has the id of the collected trace state variables.
2276 * On S/390 targets that provide the transactional-execution feature,
2277 the program interruption transaction diagnostic block (TDB) is now
2278 represented as a number of additional "registers" in GDB.
2280 * New remote packets
2284 The vCont packet supports a new 'r' action, that tells the remote
2285 stub to step through an address range itself, without GDB
2286 involvemement at each single-step.
2288 qXfer:libraries-svr4:read's annex
2289 The previously unused annex of the qXfer:libraries-svr4:read packet
2290 is now used to support passing an argument list. The remote stub
2291 reports support for this argument list to GDB's qSupported query.
2292 The defined arguments are "start" and "prev", used to reduce work
2293 necessary for library list updating, resulting in significant
2296 * New features in the GDB remote stub, GDBserver
2298 ** GDBserver now supports target-assisted range stepping. Currently
2299 enabled on x86/x86_64 GNU/Linux targets.
2301 ** GDBserver now adds element 'tvar' in the XML in the reply to
2302 'qXfer:traceframe-info:read'. It has the id of the collected
2303 trace state variables.
2305 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2308 * New 'z' formatter for printing and examining memory, this displays the
2309 value as hexadecimal zero padded on the left to the size of the type.
2311 * GDB can now use Windows x64 unwinding data.
2313 * The "set remotebaud" command has been replaced by "set serial baud".
2314 Similarly, "show remotebaud" has been replaced by "show serial baud".
2315 The "set remotebaud" and "show remotebaud" commands are still available
2316 to provide backward compatibility with older versions of GDB.
2318 *** Changes in GDB 7.6
2320 * Target record has been renamed to record-full.
2321 Record/replay is now enabled with the "record full" command.
2322 This also affects settings that are associated with full record/replay
2323 that have been moved from "set/show record" to "set/show record full":
2325 set|show record full insn-number-max
2326 set|show record full stop-at-limit
2327 set|show record full memory-query
2329 * A new record target "record-btrace" has been added. The new target
2330 uses hardware support to record the control-flow of a process. It
2331 does not support replaying the execution, but it implements the
2332 below new commands for investigating the recorded execution log.
2333 This new recording method can be enabled using:
2337 The "record-btrace" target is only available on Intel Atom processors
2338 and requires a Linux kernel 2.6.32 or later.
2340 * Two new commands have been added for record/replay to give information
2341 about the recorded execution without having to replay the execution.
2342 The commands are only supported by "record btrace".
2344 record instruction-history prints the execution history at
2345 instruction granularity
2347 record function-call-history prints the execution history at
2348 function granularity
2350 * New native configurations
2352 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2353 FreeBSD/powerpc powerpc*-*-freebsd
2354 x86_64/Cygwin x86_64-*-cygwin*
2355 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2359 ARM AArch64 aarch64*-*-elf
2360 ARM AArch64 GNU/Linux aarch64*-*-linux
2361 Lynx 178 PowerPC powerpc-*-lynx*178
2362 x86_64/Cygwin x86_64-*-cygwin*
2363 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2365 * If the configured location of system.gdbinit file (as given by the
2366 --with-system-gdbinit option at configure time) is in the
2367 data-directory (as specified by --with-gdb-datadir at configure
2368 time) or in one of its subdirectories, then GDB will look for the
2369 system-wide init file in the directory specified by the
2370 --data-directory command-line option.
2372 * New command line options:
2374 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2375 other initialization files, unlike -nx which disables all of them.
2377 * Removed command line options
2379 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2382 * The 'ptype' and 'whatis' commands now accept an argument to control
2385 * 'info proc' now works on some core files.
2389 ** Vectors can be created with gdb.Type.vector.
2391 ** Python's atexit.register now works in GDB.
2393 ** Types can be pretty-printed via a Python API.
2395 ** Python 3 is now supported (in addition to Python 2.4 or later)
2397 ** New class gdb.Architecture exposes GDB's internal representation
2398 of architecture in the Python API.
2400 ** New method Frame.architecture returns the gdb.Architecture object
2401 corresponding to the frame's architecture.
2403 * New Python-based convenience functions:
2405 ** $_memeq(buf1, buf2, length)
2406 ** $_streq(str1, str2)
2408 ** $_regex(str, regex)
2410 * The 'cd' command now defaults to using '~' (the home directory) if not
2413 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2414 default for GCC since November 2000.
2416 * The command 'forward-search' can now be abbreviated as 'fo'.
2418 * The command 'info tracepoints' can now display 'installed on target'
2419 or 'not installed on target' for each non-pending location of tracepoint.
2421 * New configure options
2423 --enable-libmcheck/--disable-libmcheck
2424 By default, development versions are built with -lmcheck on hosts
2425 that support it, in order to help track memory corruption issues.
2426 Release versions, on the other hand, are built without -lmcheck
2427 by default. The --enable-libmcheck/--disable-libmcheck configure
2428 options allow the user to override that default.
2429 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2430 This configure option allows the user to build GDB with
2431 libbabeltrace using which GDB can read Common Trace Format data.
2433 * New commands (for set/show, see "New options" below)
2436 Catch signals. This is similar to "handle", but allows commands and
2437 conditions to be attached.
2440 List the BFDs known to GDB.
2442 python-interactive [command]
2444 Start a Python interactive prompt, or evaluate the optional command
2445 and print the result of expressions.
2448 "py" is a new alias for "python".
2450 enable type-printer [name]...
2451 disable type-printer [name]...
2452 Enable or disable type printers.
2456 ** For the Renesas Super-H architecture, the "regs" command has been removed
2457 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2462 set print type methods (on|off)
2463 show print type methods
2464 Control whether method declarations are displayed by "ptype".
2465 The default is to show them.
2467 set print type typedefs (on|off)
2468 show print type typedefs
2469 Control whether typedef definitions are displayed by "ptype".
2470 The default is to show them.
2472 set filename-display basename|relative|absolute
2473 show filename-display
2474 Control the way in which filenames is displayed.
2475 The default is "relative", which preserves previous behavior.
2477 set trace-buffer-size
2478 show trace-buffer-size
2479 Request target to change the size of trace buffer.
2481 set remote trace-buffer-size-packet auto|on|off
2482 show remote trace-buffer-size-packet
2483 Control the use of the remote protocol `QTBuffer:size' packet.
2487 Control display of debugging messages related to ARM AArch64.
2490 set debug coff-pe-read
2491 show debug coff-pe-read
2492 Control display of debugging messages related to reading of COFF/PE
2497 Control display of debugging messages related to Mach-O symbols
2500 set debug notification
2501 show debug notification
2502 Control display of debugging info for async remote notification.
2506 ** Command parameter changes are now notified using new async record
2507 "=cmd-param-changed".
2508 ** Trace frame changes caused by command "tfind" are now notified using
2509 new async record "=traceframe-changed".
2510 ** The creation, deletion and modification of trace state variables
2511 are now notified using new async records "=tsv-created",
2512 "=tsv-deleted" and "=tsv-modified".
2513 ** The start and stop of process record are now notified using new
2514 async record "=record-started" and "=record-stopped".
2515 ** Memory changes are now notified using new async record
2517 ** The data-disassemble command response will include a "fullname" field
2518 containing the absolute file name when source has been requested.
2519 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2520 command, to allow pattern filling of memory areas.
2521 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2522 library load/unload events.
2523 ** The response to breakpoint commands and breakpoint async records
2524 includes an "installed" field containing a boolean state about each
2525 non-pending tracepoint location is whether installed on target or not.
2526 ** Output of the "-trace-status" command includes a "trace-file" field
2527 containing the name of the trace file being examined. This field is
2528 optional, and only present when examining a trace file.
2529 ** The "fullname" field is now always present along with the "file" field,
2530 even if the file cannot be found by GDB.
2532 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2533 You must have the LZMA library available when configuring GDB for this
2534 feature to be enabled. For more information, see:
2535 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2537 * New remote packets
2540 Set the size of trace buffer. The remote stub reports support for this
2541 packet to gdb's qSupported query.
2544 Enable Branch Trace Store (BTS)-based branch tracing for the current
2545 thread. The remote stub reports support for this packet to gdb's
2549 Disable branch tracing for the current thread. The remote stub reports
2550 support for this packet to gdb's qSupported query.
2553 Read the traced branches for the current thread. The remote stub
2554 reports support for this packet to gdb's qSupported query.
2556 *** Changes in GDB 7.5
2558 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2559 for more x32 ABI info.
2561 * GDB now supports access to MIPS DSP registers on Linux targets.
2563 * GDB now supports debugging microMIPS binaries.
2565 * The "info os" command on GNU/Linux can now display information on
2566 several new classes of objects managed by the operating system:
2567 "info os procgroups" lists process groups
2568 "info os files" lists file descriptors
2569 "info os sockets" lists internet-domain sockets
2570 "info os shm" lists shared-memory regions
2571 "info os semaphores" lists semaphores
2572 "info os msg" lists message queues
2573 "info os modules" lists loaded kernel modules
2575 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2576 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2577 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2578 options and inspect the probe arguments using the new $_probe_arg family
2579 of convenience variables. You can obtain more information about SystemTap
2580 in <http://sourceware.org/systemtap/>.
2582 * GDB now supports reversible debugging on ARM, it allows you to
2583 debug basic ARM and THUMB instructions, and provides
2584 record/replay support.
2586 * The option "symbol-reloading" has been deleted as it is no longer used.
2590 ** GDB commands implemented in Python can now be put in command class
2593 ** The "maint set python print-stack on|off" is now deleted.
2595 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2596 apply "flag enum"-style pretty-printing to any enum.
2598 ** gdb.lookup_symbol can now work when there is no current frame.
2600 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2601 the source at which the symbol was defined.
2603 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2604 method 'value'. The former indicates whether the symbol needs a
2605 frame in order to compute its value, and the latter computes the
2608 ** A new method 'referenced_value' on gdb.Value objects which can
2609 dereference pointer as well as C++ reference values.
2611 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2612 which return the global and static blocks (as gdb.Block objects),
2613 of the underlying symbol table, respectively.
2615 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2616 object associated with a PC value.
2618 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2619 of the address range occupied by code for the current source line.
2621 * Go language support.
2622 GDB now supports debugging programs written in the Go programming
2625 * GDBserver now supports stdio connections.
2626 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2628 * The binary "gdbtui" can no longer be built or installed.
2629 Use "gdb -tui" instead.
2631 * GDB will now print "flag" enums specially. A flag enum is one where
2632 all the enumerator values have no bits in common when pairwise
2633 "and"ed. When printing a value whose type is a flag enum, GDB will
2634 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2635 (gdb) print (enum E) 3
2638 * The filename part of a linespec will now match trailing components
2639 of a source file name. For example, "break gcc/expr.c:1000" will
2640 now set a breakpoint in build/gcc/expr.c, but not
2641 build/libcpp/expr.c.
2643 * The "info proc" and "generate-core-file" commands will now also
2644 work on remote targets connected to GDBserver on Linux.
2646 * The command "info catch" has been removed. It has been disabled
2647 since December 2007.
2649 * The "catch exception" and "catch assert" commands now accept
2650 a condition at the end of the command, much like the "break"
2651 command does. For instance:
2653 (gdb) catch exception Constraint_Error if Barrier = True
2655 Previously, it was possible to add a condition to such catchpoints,
2656 but it had to be done as a second step, after the catchpoint had been
2657 created, using the "condition" command.
2659 * The "info static-tracepoint-marker" command will now also work on
2660 native Linux targets with in-process agent.
2662 * GDB can now set breakpoints on inlined functions.
2664 * The .gdb_index section has been updated to include symbols for
2665 inlined functions. GDB will ignore older .gdb_index sections by
2666 default, which could cause symbol files to be loaded more slowly
2667 until their .gdb_index sections can be recreated. The new command
2668 "set use-deprecated-index-sections on" will cause GDB to use any older
2669 .gdb_index sections it finds. This will restore performance, but the
2670 ability to set breakpoints on inlined functions will be lost in symbol
2671 files with older .gdb_index sections.
2673 The .gdb_index section has also been updated to record more information
2674 about each symbol. This speeds up the "info variables", "info functions"
2675 and "info types" commands when used with programs having the .gdb_index
2676 section, as well as speeding up debugging with shared libraries using
2677 the .gdb_index section.
2679 * Ada support for GDB/MI Variable Objects has been added.
2681 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2686 ** New command -info-os is the MI equivalent of "info os".
2688 ** Output logs ("set logging" and related) now include MI output.
2692 ** "set use-deprecated-index-sections on|off"
2693 "show use-deprecated-index-sections on|off"
2694 Controls the use of deprecated .gdb_index sections.
2696 ** "catch load" and "catch unload" can be used to stop when a shared
2697 library is loaded or unloaded, respectively.
2699 ** "enable count" can be used to auto-disable a breakpoint after
2702 ** "info vtbl" can be used to show the virtual method tables for
2703 C++ and Java objects.
2705 ** "explore" and its sub commands "explore value" and "explore type"
2706 can be used to recursively explore values and types of
2707 expressions. These commands are available only if GDB is
2708 configured with '--with-python'.
2710 ** "info auto-load" shows status of all kinds of auto-loaded files,
2711 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2712 sequences of commands files, "info auto-load python-scripts"
2713 shows status of auto-loading Python script files,
2714 "info auto-load local-gdbinit" shows status of loading init file
2715 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2716 status of inferior specific thread debugging shared library loading.
2718 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2719 and "show auto-load-scripts" commands have been deprecated, use their
2720 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2721 and "show auto-load python-scripts" counterparts instead.
2723 ** "dprintf location,format,args..." creates a dynamic printf, which
2724 is basically a breakpoint that does a printf and immediately
2725 resumes your program's execution, so it is like a printf that you
2726 can insert dynamically at runtime instead of at compiletime.
2728 ** "set print symbol"
2730 Controls whether GDB attempts to display the symbol, if any,
2731 corresponding to addresses it prints. This defaults to "on", but
2732 you can set it to "off" to restore GDB's previous behavior.
2734 * Deprecated commands
2736 ** For the Renesas Super-H architecture, the "regs" command has been
2737 deprecated, and "info all-registers" should be used instead.
2741 Renesas RL78 rl78-*-elf
2742 HP OpenVMS ia64 ia64-hp-openvms*
2744 * GDBserver supports evaluation of breakpoint conditions. When
2745 support is advertised by GDBserver, GDB may be told to send the
2746 breakpoint conditions in bytecode form to GDBserver. GDBserver
2747 will only report the breakpoint trigger to GDB when its condition
2752 set mips compression
2753 show mips compression
2754 Select the compressed ISA encoding used in functions that have no symbol
2755 information available. The encoding can be set to either of:
2758 and is updated automatically from ELF file flags if available.
2760 set breakpoint condition-evaluation
2761 show breakpoint condition-evaluation
2762 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2763 GDBserver ("target"). Default option "auto" chooses the most efficient
2765 This option can improve debugger efficiency depending on the speed of the
2769 Disable auto-loading globally.
2772 Show auto-loading setting of all kinds of auto-loaded files.
2774 set auto-load gdb-scripts on|off
2775 show auto-load gdb-scripts
2776 Control auto-loading of GDB canned sequences of commands files.
2778 set auto-load python-scripts on|off
2779 show auto-load python-scripts
2780 Control auto-loading of Python script files.
2782 set auto-load local-gdbinit on|off
2783 show auto-load local-gdbinit
2784 Control loading of init file (.gdbinit) from current directory.
2786 set auto-load libthread-db on|off
2787 show auto-load libthread-db
2788 Control auto-loading of inferior specific thread debugging shared library.
2790 set auto-load scripts-directory <dir1>[:<dir2>...]
2791 show auto-load scripts-directory
2792 Set a list of directories from which to load auto-loaded scripts.
2793 Automatically loaded Python scripts and GDB scripts are located in one
2794 of the directories listed by this option.
2795 The delimiter (':' above) may differ according to the host platform.
2797 set auto-load safe-path <dir1>[:<dir2>...]
2798 show auto-load safe-path
2799 Set a list of directories from which it is safe to auto-load files.
2800 The delimiter (':' above) may differ according to the host platform.
2802 set debug auto-load on|off
2803 show debug auto-load
2804 Control display of debugging info for auto-loading the files above.
2806 set dprintf-style gdb|call|agent
2808 Control the way in which a dynamic printf is performed; "gdb"
2809 requests a GDB printf command, while "call" causes dprintf to call a
2810 function in the inferior. "agent" requests that the target agent
2811 (such as GDBserver) do the printing.
2813 set dprintf-function <expr>
2814 show dprintf-function
2815 set dprintf-channel <expr>
2816 show dprintf-channel
2817 Set the function and optional first argument to the call when using
2818 the "call" style of dynamic printf.
2820 set disconnected-dprintf on|off
2821 show disconnected-dprintf
2822 Control whether agent-style dynamic printfs continue to be in effect
2823 after GDB disconnects.
2825 * New configure options
2827 --with-auto-load-dir
2828 Configure default value for the 'set auto-load scripts-directory'
2829 setting above. It defaults to '$debugdir:$datadir/auto-load',
2830 $debugdir representing global debugging info directories (available
2831 via 'show debug-file-directory') and $datadir representing GDB's data
2832 directory (available via 'show data-directory').
2834 --with-auto-load-safe-path
2835 Configure default value for the 'set auto-load safe-path' setting
2836 above. It defaults to the --with-auto-load-dir setting.
2838 --without-auto-load-safe-path
2839 Set 'set auto-load safe-path' to '/', effectively disabling this
2842 * New remote packets
2844 z0/z1 conditional breakpoints extension
2846 The z0/z1 breakpoint insertion packets have been extended to carry
2847 a list of conditional expressions over to the remote stub depending on the
2848 condition evaluation mode. The use of this extension can be controlled
2849 via the "set remote conditional-breakpoints-packet" command.
2853 Specify the signals which the remote stub may pass to the debugged
2854 program without GDB involvement.
2856 * New command line options
2858 --init-command=FILE, -ix Like --command, -x but execute it
2859 before loading inferior.
2860 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2861 execute it before loading inferior.
2863 *** Changes in GDB 7.4
2865 * GDB now handles ambiguous linespecs more consistently; the existing
2866 FILE:LINE support has been expanded to other types of linespecs. A
2867 breakpoint will now be set on all matching locations in all
2868 inferiors, and locations will be added or removed according to
2871 * GDB now allows you to skip uninteresting functions and files when
2872 stepping with the "skip function" and "skip file" commands.
2874 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2875 and "show remote hardware-watchpoint-length-limit". These allows to
2876 set or show the maximum length limit (in bytes) of a remote
2877 target hardware watchpoint.
2879 This allows e.g. to use "unlimited" hardware watchpoints with the
2880 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2881 watchpoints are slower than real hardware watchpoints but are
2882 significantly faster than gdb software watchpoints.
2886 ** The register_pretty_printer function in module gdb.printing now takes
2887 an optional `replace' argument. If True, the new printer replaces any
2890 ** The "maint set python print-stack on|off" command has been
2891 deprecated and will be deleted in GDB 7.5.
2892 A new command: "set python print-stack none|full|message" has
2893 replaced it. Additionally, the default for "print-stack" is
2894 now "message", which just prints the error message without
2897 ** A prompt substitution hook (prompt_hook) is now available to the
2900 ** A new Python module, gdb.prompt has been added to the GDB Python
2901 modules library. This module provides functionality for
2902 escape sequences in prompts (used by set/show
2903 extended-prompt). These escape sequences are replaced by their
2904 corresponding value.
2906 ** Python commands and convenience-functions located in
2907 'data-directory'/python/gdb/command and
2908 'data-directory'/python/gdb/function are now automatically loaded
2911 ** Blocks now provide four new attributes. global_block and
2912 static_block will return the global and static blocks
2913 respectively. is_static and is_global are boolean attributes
2914 that indicate if the block is one of those two types.
2916 ** Symbols now provide the "type" attribute, the type of the symbol.
2918 ** The "gdb.breakpoint" function has been deprecated in favor of
2921 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2922 of a function. This class is based on the "finish" command
2923 available in the CLI.
2925 ** Type objects for struct and union types now allow access to
2926 the fields using standard Python dictionary (mapping) methods.
2927 For example, "some_type['myfield']" now works, as does
2928 "some_type.items()".
2930 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2933 ** A new function, "deep_items" has been added to the gdb.types
2934 module in the GDB Python modules library. This function returns
2935 an iterator over the fields of a struct or union type. Unlike
2936 the standard Python "iteritems" method, it will recursively traverse
2937 any anonymous fields.
2941 ** "*stopped" events can report several new "reason"s, such as
2944 ** Breakpoint changes are now notified using new async records, like
2945 "=breakpoint-modified".
2947 ** New command -ada-task-info.
2949 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2950 $sdir specifies the default system locations of shared libraries.
2951 $pdir specifies the directory where the libpthread used by the application
2954 GDB no longer looks in $sdir and $pdir after it has searched the directories
2955 mentioned in libthread-db-search-path. If you want to search those
2956 directories, they must be specified in libthread-db-search-path.
2957 The default value of libthread-db-search-path on GNU/Linux and Solaris
2958 systems is now "$sdir:$pdir".
2960 $pdir is not supported by gdbserver, it is currently ignored.
2961 $sdir is supported by gdbserver.
2963 * New configure option --with-iconv-bin.
2964 When using the internationalization support like the one in the GNU C
2965 library, GDB will invoke the "iconv" program to get a list of supported
2966 character sets. If this program lives in a non-standard location, one can
2967 use this option to specify where to find it.
2969 * When natively debugging programs on PowerPC BookE processors running
2970 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2971 watchpoints, which specify a mask in addition to an address to watch.
2972 The mask specifies that some bits of an address (the bits which are
2973 reset in the mask) should be ignored when matching the address accessed
2974 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2975 section in the user manual for more details.
2977 * The new option --once causes GDBserver to stop listening for connections once
2978 the first connection is made. The listening port used by GDBserver will
2979 become available after that.
2981 * New commands "info macros" and "alias" have been added.
2983 * New function parameters suffix @entry specifies value of function parameter
2984 at the time the function got called. Entry values are available only since
2990 "!" is now an alias of the "shell" command.
2991 Note that no space is needed between "!" and SHELL COMMAND.
2995 watch EXPRESSION mask MASK_VALUE
2996 The watch command now supports the mask argument which allows creation
2997 of masked watchpoints, if the current architecture supports this feature.
2999 info auto-load-scripts [REGEXP]
3000 This command was formerly named "maintenance print section-scripts".
3001 It is now generally useful and is no longer a maintenance-only command.
3003 info macro [-all] [--] MACRO
3004 The info macro command has new options `-all' and `--'. The first for
3005 printing all definitions of a macro. The second for explicitly specifying
3006 the end of arguments and the beginning of the macro name in case the macro
3007 name starts with a hyphen.
3009 collect[/s] EXPRESSIONS
3010 The tracepoint collect command now takes an optional modifier "/s"
3011 that directs it to dereference pointer-to-character types and
3012 collect the bytes of memory up to a zero byte. The behavior is
3013 similar to what you see when you use the regular print command on a
3014 string. An optional integer following the "/s" sets a bound on the
3015 number of bytes that will be collected.
3018 The trace start command now interprets any supplied arguments as a
3019 note to be recorded with the trace run, with an effect similar to
3020 setting the variable trace-notes.
3023 The trace stop command now interprets any arguments as a note to be
3024 mentioned along with the tstatus report that the trace was stopped
3025 with a command. The effect is similar to setting the variable
3028 * Tracepoints can now be enabled and disabled at any time after a trace
3029 experiment has been started using the standard "enable" and "disable"
3030 commands. It is now possible to start a trace experiment with no enabled
3031 tracepoints; GDB will display a warning, but will allow the experiment to
3032 begin, assuming that tracepoints will be enabled as needed while the trace
3035 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3036 locations with 4-byte instructions, when they were previously
3037 limited to locations with instructions of 5 bytes or longer.
3041 set debug dwarf2-read
3042 show debug dwarf2-read
3043 Turns on or off display of debugging messages related to reading
3044 DWARF debug info. The default is off.
3046 set debug symtab-create
3047 show debug symtab-create
3048 Turns on or off display of debugging messages related to symbol table
3049 creation. The default is off.
3052 show extended-prompt
3053 Set the GDB prompt, and allow escape sequences to be inserted to
3054 display miscellaneous information (see 'help set extended-prompt'
3055 for the list of sequences). This prompt (and any information
3056 accessed through the escape sequences) is updated every time the
3057 prompt is displayed.
3059 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3060 show print entry-values
3061 Set printing of frame argument values at function entry. In some cases
3062 GDB can determine the value of function argument which was passed by the
3063 function caller, even if the value was modified inside the called function.
3065 set debug entry-values
3066 show debug entry-values
3067 Control display of debugging info for determining frame argument values at
3068 function entry and virtual tail call frames.
3070 set basenames-may-differ
3071 show basenames-may-differ
3072 Set whether a source file may have multiple base names.
3073 (A "base name" is the name of a file with the directory part removed.
3074 Example: The base name of "/home/user/hello.c" is "hello.c".)
3075 If set, GDB will canonicalize file names (e.g., expand symlinks)
3076 before comparing them. Canonicalization is an expensive operation,
3077 but it allows the same file be known by more than one base name.
3078 If not set (the default), all source files are assumed to have just
3079 one base name, and gdb will do file name comparisons more efficiently.
3085 Set a user name and notes for the current and any future trace runs.
3086 This is useful for long-running and/or disconnected traces, to
3087 inform others (or yourself) as to who is running the trace, supply
3088 contact information, or otherwise explain what is going on.
3090 set trace-stop-notes
3091 show trace-stop-notes
3092 Set a note attached to the trace run, that is displayed when the
3093 trace has been stopped by a tstop command. This is useful for
3094 instance as an explanation, if you are stopping a trace run that was
3095 started by someone else.
3097 * New remote packets
3101 Dynamically enable a tracepoint in a started trace experiment.
3105 Dynamically disable a tracepoint in a started trace experiment.
3109 Set the user and notes of the trace run.
3113 Query the current status of a tracepoint.
3117 Query the minimum length of instruction at which a fast tracepoint may
3120 * Dcache size (number of lines) and line-size are now runtime-configurable
3121 via "set dcache line" and "set dcache line-size" commands.
3125 Texas Instruments TMS320C6x tic6x-*-*
3129 Renesas RL78 rl78-*-elf
3131 *** Changes in GDB 7.3.1
3133 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3135 *** Changes in GDB 7.3
3137 * GDB has a new command: "thread find [REGEXP]".
3138 It finds the thread id whose name, target id, or thread extra info
3139 matches the given regular expression.
3141 * The "catch syscall" command now works on mips*-linux* targets.
3143 * The -data-disassemble MI command now supports modes 2 and 3 for
3144 dumping the instruction opcodes.
3146 * New command line options
3148 -data-directory DIR Specify DIR as the "data-directory".
3149 This is mostly for testing purposes.
3151 * The "maint set python auto-load on|off" command has been renamed to
3152 "set auto-load-scripts on|off".
3154 * GDB has a new command: "set directories".
3155 It is like the "dir" command except that it replaces the
3156 source path list instead of augmenting it.
3158 * GDB now understands thread names.
3160 On GNU/Linux, "info threads" will display the thread name as set by
3161 prctl or pthread_setname_np.
3163 There is also a new command, "thread name", which can be used to
3164 assign a name internally for GDB to display.
3167 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3168 has been integrated into GDB.
3172 ** The function gdb.Write now accepts an optional keyword 'stream'.
3173 This keyword, when provided, will direct the output to either
3174 stdout, stderr, or GDB's logging output.
3176 ** Parameters can now be be sub-classed in Python, and in particular
3177 you may implement the get_set_doc and get_show_doc functions.
3178 This improves how Parameter set/show documentation is processed
3179 and allows for more dynamic content.
3181 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3182 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3183 have an is_valid method.
3185 ** Breakpoints can now be sub-classed in Python, and in particular
3186 you may implement a 'stop' function that is executed each time
3187 the inferior reaches that breakpoint.
3189 ** New function gdb.lookup_global_symbol looks up a global symbol.
3191 ** GDB values in Python are now callable if the value represents a
3192 function. For example, if 'some_value' represents a function that
3193 takes two integer parameters and returns a value, you can call
3194 that function like so:
3196 result = some_value (10,20)
3198 ** Module gdb.types has been added.
3199 It contains a collection of utilities for working with gdb.Types objects:
3200 get_basic_type, has_field, make_enum_dict.
3202 ** Module gdb.printing has been added.
3203 It contains utilities for writing and registering pretty-printers.
3204 New classes: PrettyPrinter, SubPrettyPrinter,
3205 RegexpCollectionPrettyPrinter.
3206 New function: register_pretty_printer.
3208 ** New commands "info pretty-printers", "enable pretty-printer" and
3209 "disable pretty-printer" have been added.
3211 ** gdb.parameter("directories") is now available.
3213 ** New function gdb.newest_frame returns the newest frame in the
3216 ** The gdb.InferiorThread class has a new "name" attribute. This
3217 holds the thread's name.
3219 ** Python Support for Inferior events.
3220 Python scripts can add observers to be notified of events
3221 occurring in the process being debugged.
3222 The following events are currently supported:
3223 - gdb.events.cont Continue event.
3224 - gdb.events.exited Inferior exited event.
3225 - gdb.events.stop Signal received, and Breakpoint hit events.
3229 ** GDB now puts template parameters in scope when debugging in an
3230 instantiation. For example, if you have:
3232 template<int X> int func (void) { return X; }
3234 then if you step into func<5>, "print X" will show "5". This
3235 feature requires proper debuginfo support from the compiler; it
3236 was added to GCC 4.5.
3238 ** The motion commands "next", "finish", "until", and "advance" now
3239 work better when exceptions are thrown. In particular, GDB will
3240 no longer lose control of the inferior; instead, the GDB will
3241 stop the inferior at the point at which the exception is caught.
3242 This functionality requires a change in the exception handling
3243 code that was introduced in GCC 4.5.
3245 * GDB now follows GCC's rules on accessing volatile objects when
3246 reading or writing target state during expression evaluation.
3247 One notable difference to prior behavior is that "print x = 0"
3248 no longer generates a read of x; the value of the assignment is
3249 now always taken directly from the value being assigned.
3251 * GDB now has some support for using labels in the program's source in
3252 linespecs. For instance, you can use "advance label" to continue
3253 execution to a label.
3255 * GDB now has support for reading and writing a new .gdb_index
3256 section. This section holds a fast index of DWARF debugging
3257 information and can be used to greatly speed up GDB startup and
3258 operation. See the documentation for `save gdb-index' for details.
3260 * The "watch" command now accepts an optional "-location" argument.
3261 When used, this causes GDB to watch the memory referred to by the
3262 expression. Such a watchpoint is never deleted due to it going out
3265 * GDB now supports thread debugging of core dumps on GNU/Linux.
3267 GDB now activates thread debugging using the libthread_db library
3268 when debugging GNU/Linux core dumps, similarly to when debugging
3269 live processes. As a result, when debugging a core dump file, GDB
3270 is now able to display pthread_t ids of threads. For example, "info
3271 threads" shows the same output as when debugging the process when it
3272 was live. In earlier releases, you'd see something like this:
3275 * 1 LWP 6780 main () at main.c:10
3277 While now you see this:
3280 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3282 It is also now possible to inspect TLS variables when debugging core
3285 When debugging a core dump generated on a machine other than the one
3286 used to run GDB, you may need to point GDB at the correct
3287 libthread_db library with the "set libthread-db-search-path"
3288 command. See the user manual for more details on this command.
3290 * When natively debugging programs on PowerPC BookE processors running
3291 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3292 which stop execution of the inferior whenever it executes an instruction
3293 at any address within the specified range. See the "PowerPC Embedded"
3294 section in the user manual for more details.
3296 * New features in the GDB remote stub, GDBserver
3298 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3299 and i686 LynxOS (version 5.x).
3301 ** GDBserver is now supported on Blackfin Linux.
3303 * New native configurations
3305 ia64 HP-UX ia64-*-hpux*
3309 Analog Devices, Inc. Blackfin Processor bfin-*
3311 * Ada task switching is now supported on sparc-elf targets when
3312 debugging a program using the Ravenscar Profile. For more information,
3313 see the "Tasking Support when using the Ravenscar Profile" section
3314 in the GDB user manual.
3316 * Guile support was removed.
3318 * New features in the GNU simulator
3320 ** The --map-info flag lists all known core mappings.
3322 ** CFI flashes may be simulated via the "cfi" device.
3324 *** Changes in GDB 7.2
3326 * Shared library support for remote targets by default
3328 When GDB is configured for a generic, non-OS specific target, like
3329 for example, --target=arm-eabi or one of the many *-*-elf targets,
3330 GDB now queries remote stubs for loaded shared libraries using the
3331 `qXfer:libraries:read' packet. Previously, shared library support
3332 was always disabled for such configurations.
3336 ** Argument Dependent Lookup (ADL)
3338 In C++ ADL lookup directs function search to the namespaces of its
3339 arguments even if the namespace has not been imported.
3349 Here the compiler will search for `foo' in the namespace of 'b'
3350 and find A::foo. GDB now supports this. This construct is commonly
3351 used in the Standard Template Library for operators.
3353 ** Improved User Defined Operator Support
3355 In addition to member operators, GDB now supports lookup of operators
3356 defined in a namespace and imported with a `using' directive, operators
3357 defined in the global scope, operators imported implicitly from an
3358 anonymous namespace, and the ADL operators mentioned in the previous
3360 GDB now also supports proper overload resolution for all the previously
3361 mentioned flavors of operators.
3363 ** static const class members
3365 Printing of static const class members that are initialized in the
3366 class definition has been fixed.
3368 * Windows Thread Information Block access.
3370 On Windows targets, GDB now supports displaying the Windows Thread
3371 Information Block (TIB) structure. This structure is visible either
3372 by using the new command `info w32 thread-information-block' or, by
3373 dereferencing the new convenience variable named `$_tlb', a
3374 thread-specific pointer to the TIB. This feature is also supported
3375 when remote debugging using GDBserver.
3377 * Static tracepoints
3379 Static tracepoints are calls in the user program into a tracing
3380 library. One such library is a port of the LTTng kernel tracer to
3381 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3382 When debugging with GDBserver, GDB now supports combining the GDB
3383 tracepoint machinery with such libraries. For example: the user can
3384 use GDB to probe a static tracepoint marker (a call from the user
3385 program into the tracing library) with the new "strace" command (see
3386 "New commands" below). This creates a "static tracepoint" in the
3387 breakpoint list, that can be manipulated with the same feature set
3388 as fast and regular tracepoints. E.g., collect registers, local and
3389 global variables, collect trace state variables, and define
3390 tracepoint conditions. In addition, the user can collect extra
3391 static tracepoint marker specific data, by collecting the new
3392 $_sdata internal variable. When analyzing the trace buffer, you can
3393 inspect $_sdata like any other variable available to GDB. For more
3394 information, see the "Tracepoints" chapter in GDB user manual. New
3395 remote packets have been defined to support static tracepoints, see
3396 the "New remote packets" section below.
3398 * Better reconstruction of tracepoints after disconnected tracing
3400 GDB will attempt to download the original source form of tracepoint
3401 definitions when starting a trace run, and then will upload these
3402 upon reconnection to the target, resulting in a more accurate
3403 reconstruction of the tracepoints that are in use on the target.
3407 You can now exercise direct control over the ways that GDB can
3408 affect your program. For instance, you can disallow the setting of
3409 breakpoints, so that the program can run continuously (assuming
3410 non-stop mode). In addition, the "observer" variable is available
3411 to switch all of the different controls; in observer mode, GDB
3412 cannot affect the target's behavior at all, which is useful for
3413 tasks like diagnosing live systems in the field.
3415 * The new convenience variable $_thread holds the number of the
3418 * New remote packets
3422 Return the address of the Windows Thread Information Block of a given thread.
3426 In response to several of the tracepoint packets, the target may now
3427 also respond with a number of intermediate `qRelocInsn' request
3428 packets before the final result packet, to have GDB handle
3429 relocating an instruction to execute at a different address. This
3430 is particularly useful for stubs that support fast tracepoints. GDB
3431 reports support for this feature in the qSupported packet.
3435 List static tracepoint markers in the target program.
3439 List static tracepoint markers at a given address in the target
3442 qXfer:statictrace:read
3444 Read the static trace data collected (by a `collect $_sdata'
3445 tracepoint action). The remote stub reports support for this packet
3446 to gdb's qSupported query.
3450 Send the current settings of GDB's permission flags.
3454 Send part of the source (textual) form of a tracepoint definition,
3455 which includes location, conditional, and action list.
3457 * The source command now accepts a -s option to force searching for the
3458 script in the source search path even if the script name specifies
3461 * New features in the GDB remote stub, GDBserver
3463 - GDBserver now support tracepoints (including fast tracepoints, and
3464 static tracepoints). The feature is currently supported by the
3465 i386-linux and amd64-linux builds. See the "Tracepoints support
3466 in gdbserver" section in the manual for more information.
3468 GDBserver JIT compiles the tracepoint's conditional agent
3469 expression bytecode into native code whenever possible for low
3470 overhead dynamic tracepoints conditionals. For such tracepoints,
3471 an expression that examines program state is evaluated when the
3472 tracepoint is reached, in order to determine whether to capture
3473 trace data. If the condition is simple and false, processing the
3474 tracepoint finishes very quickly and no data is gathered.
3476 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3477 for static tracepoints support.
3479 - GDBserver now supports x86_64 Windows 64-bit debugging.
3481 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3482 it understands register description.
3484 * The --batch flag now disables pagination and queries.
3486 * X86 general purpose registers
3488 GDB now supports reading/writing byte, word and double-word x86
3489 general purpose registers directly. This means you can use, say,
3490 $ah or $ax to refer, respectively, to the byte register AH and
3491 16-bit word register AX that are actually portions of the 32-bit
3492 register EAX or 64-bit register RAX.
3494 * The `commands' command now accepts a range of breakpoints to modify.
3495 A plain `commands' following a command that creates multiple
3496 breakpoints affects all the breakpoints set by that command. This
3497 applies to breakpoints set by `rbreak', and also applies when a
3498 single `break' command creates multiple breakpoints (e.g.,
3499 breakpoints on overloaded c++ functions).
3501 * The `rbreak' command now accepts a filename specification as part of
3502 its argument, limiting the functions selected by the regex to those
3503 in the specified file.
3505 * Support for remote debugging Windows and SymbianOS shared libraries
3506 from Unix hosts has been improved. Non Windows GDB builds now can
3507 understand target reported file names that follow MS-DOS based file
3508 system semantics, such as file names that include drive letters and
3509 use the backslash character as directory separator. This makes it
3510 possible to transparently use the "set sysroot" and "set
3511 solib-search-path" on Unix hosts to point as host copies of the
3512 target's shared libraries. See the new command "set
3513 target-file-system-kind" described below, and the "Commands to
3514 specify files" section in the user manual for more information.
3518 eval template, expressions...
3519 Convert the values of one or more expressions under the control
3520 of the string template to a command line, and call it.
3522 set target-file-system-kind unix|dos-based|auto
3523 show target-file-system-kind
3524 Set or show the assumed file system kind for target reported file
3527 save breakpoints <filename>
3528 Save all current breakpoint definitions to a file suitable for use
3529 in a later debugging session. To read the saved breakpoint
3530 definitions, use the `source' command.
3532 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3535 info static-tracepoint-markers
3536 Display information about static tracepoint markers in the target.
3538 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3539 Define a static tracepoint by probing a marker at the given
3540 function, line, address, or marker ID.
3544 Enable and disable observer mode.
3546 set may-write-registers on|off
3547 set may-write-memory on|off
3548 set may-insert-breakpoints on|off
3549 set may-insert-tracepoints on|off
3550 set may-insert-fast-tracepoints on|off
3551 set may-interrupt on|off
3552 Set individual permissions for GDB effects on the target. Note that
3553 some of these settings can have undesirable or surprising
3554 consequences, particularly when changed in the middle of a session.
3555 For instance, disabling the writing of memory can prevent
3556 breakpoints from being inserted, cause single-stepping to fail, or
3557 even crash your program, if you disable after breakpoints have been
3558 inserted. However, GDB should not crash.
3560 set record memory-query on|off
3561 show record memory-query
3562 Control whether to stop the inferior if memory changes caused
3563 by an instruction cannot be recorded.
3568 The disassemble command now supports "start,+length" form of two arguments.
3572 ** GDB now provides a new directory location, called the python directory,
3573 where Python scripts written for GDB can be installed. The location
3574 of that directory is <data-directory>/python, where <data-directory>
3575 is the GDB data directory. For more details, see section `Scripting
3576 GDB using Python' in the manual.
3578 ** The GDB Python API now has access to breakpoints, symbols, symbol
3579 tables, program spaces, inferiors, threads and frame's code blocks.
3580 Additionally, GDB Parameters can now be created from the API, and
3581 manipulated via set/show in the CLI.
3583 ** New functions gdb.target_charset, gdb.target_wide_charset,
3584 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3586 ** New exception gdb.GdbError.
3588 ** Pretty-printers are now also looked up in the current program space.
3590 ** Pretty-printers can now be individually enabled and disabled.
3592 ** GDB now looks for names of Python scripts to auto-load in a
3593 special section named `.debug_gdb_scripts', in addition to looking
3594 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3596 * Tracepoint actions were unified with breakpoint commands. In particular,
3597 there are no longer differences in "info break" output for breakpoints and
3598 tracepoints and the "commands" command can be used for both tracepoints and
3599 regular breakpoints.
3603 ARM Symbian arm*-*-symbianelf*
3605 * D language support.
3606 GDB now supports debugging programs written in the D programming
3609 * GDB now supports the extended ptrace interface for PowerPC which is
3610 available since Linux kernel version 2.6.34. This automatically enables
3611 any hardware breakpoints and additional hardware watchpoints available in
3612 the processor. The old ptrace interface exposes just one hardware
3613 watchpoint and no hardware breakpoints.
3615 * GDB is now able to use the Data Value Compare (DVC) register available on
3616 embedded PowerPC processors to implement in hardware simple watchpoint
3617 conditions of the form:
3619 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3621 This works in native GDB running on Linux kernels with the extended ptrace
3622 interface mentioned above.
3624 *** Changes in GDB 7.1
3628 ** Namespace Support
3630 GDB now supports importing of namespaces in C++. This enables the
3631 user to inspect variables from imported namespaces. Support for
3632 namepace aliasing has also been added. So, if a namespace is
3633 aliased in the current scope (e.g. namepace C=A; ) the user can
3634 print variables using the alias (e.g. (gdb) print C::x).
3638 All known bugs relating to the printing of virtual base class were
3639 fixed. It is now possible to call overloaded static methods using a
3644 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3645 and reinterpret_cast<> are now handled by the C++ expression parser.
3649 Xilinx MicroBlaze microblaze-*-*
3654 Xilinx MicroBlaze microblaze
3657 * Multi-program debugging.
3659 GDB now has support for multi-program (a.k.a. multi-executable or
3660 multi-exec) debugging. This allows for debugging multiple inferiors
3661 simultaneously each running a different program under the same GDB
3662 session. See "Debugging Multiple Inferiors and Programs" in the
3663 manual for more information. This implied some user visible changes
3664 in the multi-inferior support. For example, "info inferiors" now
3665 lists inferiors that are not running yet or that have exited
3666 already. See also "New commands" and "New options" below.
3668 * New tracing features
3670 GDB's tracepoint facility now includes several new features:
3672 ** Trace state variables
3674 GDB tracepoints now include support for trace state variables, which
3675 are variables managed by the target agent during a tracing
3676 experiment. They are useful for tracepoints that trigger each
3677 other, so for instance one tracepoint can count hits in a variable,
3678 and then a second tracepoint has a condition that is true when the
3679 count reaches a particular value. Trace state variables share the
3680 $-syntax of GDB convenience variables, and can appear in both
3681 tracepoint actions and condition expressions. Use the "tvariable"
3682 command to create, and "info tvariables" to view; see "Trace State
3683 Variables" in the manual for more detail.
3687 GDB now includes an option for defining fast tracepoints, which
3688 targets may implement more efficiently, such as by installing a jump
3689 into the target agent rather than a trap instruction. The resulting
3690 speedup can be by two orders of magnitude or more, although the
3691 tradeoff is that some program locations on some target architectures
3692 might not allow fast tracepoint installation, for instance if the
3693 instruction to be replaced is shorter than the jump. To request a
3694 fast tracepoint, use the "ftrace" command, with syntax identical to
3695 the regular trace command.
3697 ** Disconnected tracing
3699 It is now possible to detach GDB from the target while it is running
3700 a trace experiment, then reconnect later to see how the experiment
3701 is going. In addition, a new variable disconnected-tracing lets you
3702 tell the target agent whether to continue running a trace if the
3703 connection is lost unexpectedly.
3707 GDB now has the ability to save the trace buffer into a file, and
3708 then use that file as a target, similarly to you can do with
3709 corefiles. You can select trace frames, print data that was
3710 collected in them, and use tstatus to display the state of the
3711 tracing run at the moment that it was saved. To create a trace
3712 file, use "tsave <filename>", and to use it, do "target tfile
3715 ** Circular trace buffer
3717 You can ask the target agent to handle the trace buffer as a
3718 circular buffer, discarding the oldest trace frames to make room for
3719 newer ones, by setting circular-trace-buffer to on. This feature may
3720 not be available for all target agents.
3725 The disassemble command, when invoked with two arguments, now requires
3726 the arguments to be comma-separated.
3729 The info variables command now displays variable definitions. Files
3730 which only declare a variable are not shown.
3733 The source command is now capable of sourcing Python scripts.
3734 This feature is dependent on the debugger being build with Python
3737 Related to this enhancement is also the introduction of a new command
3738 "set script-extension" (see below).
3740 * New commands (for set/show, see "New options" below)
3742 record save [<FILENAME>]
3743 Save a file (in core file format) containing the process record
3744 execution log for replay debugging at a later time.
3746 record restore <FILENAME>
3747 Restore the process record execution log that was saved at an
3748 earlier time, for replay debugging.
3750 add-inferior [-copies <N>] [-exec <FILENAME>]
3753 clone-inferior [-copies <N>] [ID]
3754 Make a new inferior ready to execute the same program another
3755 inferior has loaded.
3760 maint info program-spaces
3761 List the program spaces loaded into GDB.
3763 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3764 show remote interrupt-sequence
3765 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3766 as the sequence to the remote target in order to interrupt the execution.
3767 Ctrl-C is a default. Some system prefers BREAK which is high level of
3768 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3769 Magic SysRq g. It is BREAK signal and character 'g'.
3771 set remote interrupt-on-connect [on | off]
3772 show remote interrupt-on-connect
3773 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3774 remote target when gdb connects to it. This is needed when you debug
3777 set remotebreak [on | off]
3779 Deprecated. Use "set/show remote interrupt-sequence" instead.
3781 tvariable $NAME [ = EXP ]
3782 Create or modify a trace state variable.
3785 List trace state variables and their values.
3787 delete tvariable $NAME ...
3788 Delete one or more trace state variables.
3791 Evaluate the given expressions without collecting anything into the
3792 trace buffer. (Valid in tracepoint actions only.)
3794 ftrace FN / FILE:LINE / *ADDR
3795 Define a fast tracepoint at the given function, line, or address.
3797 * New expression syntax
3799 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3800 GDB now parses 0b101010 identically with 42.
3804 set follow-exec-mode new|same
3805 show follow-exec-mode
3806 Control whether GDB reuses the same inferior across an exec call or
3807 creates a new one. This is useful to be able to restart the old
3808 executable after the inferior having done an exec call.
3810 set default-collect EXPR, ...
3811 show default-collect
3812 Define a list of expressions to be collected at each tracepoint.
3813 This is a useful way to ensure essential items are not overlooked,
3814 such as registers or a critical global variable.
3816 set disconnected-tracing
3817 show disconnected-tracing
3818 If set to 1, the target is instructed to continue tracing if it
3819 loses its connection to GDB. If 0, the target is to stop tracing
3822 set circular-trace-buffer
3823 show circular-trace-buffer
3824 If set to on, the target is instructed to use a circular trace buffer
3825 and discard the oldest trace frames instead of stopping the trace due
3826 to a full trace buffer. If set to off, the trace stops when the buffer
3827 fills up. Some targets may not support this.
3829 set script-extension off|soft|strict
3830 show script-extension
3831 If set to "off", the debugger does not perform any script language
3832 recognition, and all sourced files are assumed to be GDB scripts.
3833 If set to "soft" (the default), files are sourced according to
3834 filename extension, falling back to GDB scripts if the first
3836 If set to "strict", files are sourced according to filename extension.
3838 set ada trust-PAD-over-XVS on|off
3839 show ada trust-PAD-over-XVS
3840 If off, activate a workaround against a bug in the debugging information
3841 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3842 the GCC sources for more information about the GNAT encoding and
3843 PAD types in particular). It is always safe to set this option to
3844 off, but this introduces a slight performance penalty. The default
3847 * Python API Improvements
3849 ** GDB provides the new class gdb.LazyString. This is useful in
3850 some pretty-printing cases. The new method gdb.Value.lazy_string
3851 provides a simple way to create objects of this type.
3853 ** The fields returned by gdb.Type.fields now have an
3854 `is_base_class' attribute.
3856 ** The new method gdb.Type.range returns the range of an array type.
3858 ** The new method gdb.parse_and_eval can be used to parse and
3859 evaluate an expression.
3861 * New remote packets
3864 Define a trace state variable.
3867 Get the current value of a trace state variable.
3870 Set desired tracing behavior upon disconnection.
3873 Set the trace buffer to be linear or circular.
3876 Get data about the tracepoints currently in use.
3880 Process record now works correctly with hardware watchpoints.
3882 Multiple bug fixes have been made to the mips-irix port, making it
3883 much more reliable. In particular:
3884 - Debugging threaded applications is now possible again. Previously,
3885 GDB would hang while starting the program, or while waiting for
3886 the program to stop at a breakpoint.
3887 - Attaching to a running process no longer hangs.
3888 - An error occurring while loading a core file has been fixed.
3889 - Changing the value of the PC register now works again. This fixes
3890 problems observed when using the "jump" command, or when calling
3891 a function from GDB, or even when assigning a new value to $pc.
3892 - With the "finish" and "return" commands, the return value for functions
3893 returning a small array is now correctly printed.
3894 - It is now possible to break on shared library code which gets executed
3895 during a shared library init phase (code executed while executing
3896 their .init section). Previously, the breakpoint would have no effect.
3897 - GDB is now able to backtrace through the signal handler for
3898 non-threaded programs.
3900 PIE (Position Independent Executable) programs debugging is now supported.
3901 This includes debugging execution of PIC (Position Independent Code) shared
3902 libraries although for that, it should be possible to run such libraries as an
3905 *** Changes in GDB 7.0
3907 * GDB now has an interface for JIT compilation. Applications that
3908 dynamically generate code can create symbol files in memory and register
3909 them with GDB. For users, the feature should work transparently, and
3910 for JIT developers, the interface is documented in the GDB manual in the
3911 "JIT Compilation Interface" chapter.
3913 * Tracepoints may now be conditional. The syntax is as for
3914 breakpoints; either an "if" clause appended to the "trace" command,
3915 or the "condition" command is available. GDB sends the condition to
3916 the target for evaluation using the same bytecode format as is used
3917 for tracepoint actions.
3919 * The disassemble command now supports: an optional /r modifier, print the
3920 raw instructions in hex as well as in symbolic form, and an optional /m
3921 modifier to print mixed source+assembly.
3923 * Process record and replay
3925 In a architecture environment that supports ``process record and
3926 replay'', ``process record and replay'' target can record a log of
3927 the process execution, and replay it with both forward and reverse
3930 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3931 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3932 set execution-direction {forward|reverse}, for targets that support
3935 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3936 feature is available with a native GDB running on kernel version
3939 * GDB now has support for multi-byte and wide character sets on the
3940 target. Strings whose character type is wchar_t, char16_t, or
3941 char32_t are now correctly printed. GDB supports wide- and unicode-
3942 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3943 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3944 `printf'. This feature requires iconv to work properly; if your
3945 system does not have a working iconv, GDB can use GNU libiconv. See
3946 the installation instructions for more information.
3948 * GDB now supports automatic retrieval of shared library files from
3949 remote targets. To use this feature, specify a system root that begins
3950 with the `remote:' prefix, either via the `set sysroot' command or via
3951 the `--with-sysroot' configure-time option.
3953 * "info sharedlibrary" now takes an optional regex of libraries to show,
3954 and it now reports if a shared library has no debugging information.
3956 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3957 now complete on file names.
3959 * When completing in expressions, gdb will attempt to limit
3960 completions to allowable structure or union fields, where appropriate.
3961 For instance, consider:
3963 # struct example { int f1; double f2; };
3964 # struct example variable;
3967 If the user types TAB at the end of this command line, the available
3968 completions will be "f1" and "f2".
3970 * Inlined functions are now supported. They show up in backtraces, and
3971 the "step", "next", and "finish" commands handle them automatically.
3973 * GDB now supports the token-splicing (##) and stringification (#)
3974 operators when expanding macros. It also supports variable-arity
3977 * GDB now supports inspecting extra signal information, exported by
3978 the new $_siginfo convenience variable. The feature is currently
3979 implemented on linux ARM, i386 and amd64.
3981 * GDB can now display the VFP floating point registers and NEON vector
3982 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3983 can provide these registers (requires Linux 2.6.30 or later). Remote
3984 and simulator targets may also provide them.
3986 * New remote packets
3989 Search memory for a sequence of bytes.
3992 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3993 operation over reliable transport links. Use of this packet is
3994 controlled by the `set remote noack-packet' command.
3997 Kill the process with the specified process ID. Use this in preference
3998 to `k' when multiprocess protocol extensions are supported.
4001 Obtains additional operating system information
4005 Read or write additional signal information.
4007 * Removed remote protocol undocumented extension
4009 An undocumented extension to the remote protocol's `S' stop reply
4010 packet that permited the stub to pass a process id was removed.
4011 Remote servers should use the `T' stop reply packet instead.
4013 * GDB now supports multiple function calling conventions according to the
4014 DWARF-2 DW_AT_calling_convention function attribute.
4016 * The SH target utilizes the aforementioned change to distinguish between gcc
4017 and Renesas calling convention. It also adds the new CLI commands
4018 `set/show sh calling-convention'.
4020 * GDB can now read compressed debug sections, as produced by GNU gold
4021 with the --compress-debug-sections=zlib flag.
4023 * 64-bit core files are now supported on AIX.
4025 * Thread switching is now supported on Tru64.
4027 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4028 which will be allocated using malloc later in program execution.
4030 * The qXfer:libraries:read remote procotol packet now allows passing a
4031 list of section offsets.
4033 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4034 conditions handling signals delivered during attach or thread creation
4035 have also been fixed.
4037 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4038 From the user's standpoint, all unqualified instances of True and False
4039 are treated as the standard definitions, regardless of context.
4041 * GDB now parses C++ symbol and type names more flexibly. For
4044 template<typename T> class C { };
4047 GDB will now correctly handle all of:
4049 ptype C<char const *>
4050 ptype C<char const*>
4051 ptype C<const char *>
4052 ptype C<const char*>
4054 * New features in the GDB remote stub, gdbserver
4056 - The "--wrapper" command-line argument tells gdbserver to use a
4057 wrapper program to launch programs for debugging.
4059 - On PowerPC and S/390 targets, it is now possible to use a single
4060 gdbserver executable to debug both 32-bit and 64-bit programs.
4061 (This requires gdbserver itself to be built as a 64-bit executable.)
4063 - gdbserver uses the new noack protocol mode for TCP connections to
4064 reduce communications latency, if also supported and enabled in GDB.
4066 - Support for the sparc64-linux-gnu target is now included in
4069 - The amd64-linux build of gdbserver now supports debugging both
4070 32-bit and 64-bit programs.
4072 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4073 now support hardware watchpoints, and will use them automatically
4078 GDB now has support for scripting using Python. Whether this is
4079 available is determined at configure time.
4081 New GDB commands can now be written in Python.
4083 * Ada tasking support
4085 Ada tasks can now be inspected in GDB. The following commands have
4089 Print the list of Ada tasks.
4091 Print detailed information about task number N.
4093 Print the task number of the current task.
4095 Switch the context of debugging to task number N.
4097 * Support for user-defined prefixed commands. The "define" command can
4098 add new commands to existing prefixes, e.g. "target".
4100 * Multi-inferior, multi-process debugging.
4102 GDB now has generalized support for multi-inferior debugging. See
4103 "Debugging Multiple Inferiors" in the manual for more information.
4104 Although availability still depends on target support, the command
4105 set is more uniform now. The GNU/Linux specific multi-forks support
4106 has been migrated to this new framework. This implied some user
4107 visible changes; see "New commands" and also "Removed commands"
4110 * Target descriptions can now describe the target OS ABI. See the
4111 "Target Description Format" section in the user manual for more
4114 * Target descriptions can now describe "compatible" architectures
4115 to indicate that the target can execute applications for a different
4116 architecture in addition to those for the main target architecture.
4117 See the "Target Description Format" section in the user manual for
4120 * Multi-architecture debugging.
4122 GDB now includes general supports for debugging applications on
4123 hybrid systems that use more than one single processor architecture
4124 at the same time. Each such hybrid architecture still requires
4125 specific support to be added. The only hybrid architecture supported
4126 in this version of GDB is the Cell Broadband Engine.
4128 * GDB now supports integrated debugging of Cell/B.E. applications that
4129 use both the PPU and SPU architectures. To enable support for hybrid
4130 Cell/B.E. debugging, you need to configure GDB to support both the
4131 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4132 --enable-targets configure option.
4134 * Non-stop mode debugging.
4136 For some targets, GDB now supports an optional mode of operation in
4137 which you can examine stopped threads while other threads continue
4138 to execute freely. This is referred to as non-stop mode, with the
4139 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4140 section in the user manual for more information.
4142 To be able to support remote non-stop debugging, a remote stub needs
4143 to implement the non-stop mode remote protocol extensions, as
4144 described in the "Remote Non-Stop" section of the user manual. The
4145 GDB remote stub, gdbserver, has been adjusted to support these
4146 extensions on linux targets.
4148 * New commands (for set/show, see "New options" below)
4150 catch syscall [NAME(S) | NUMBER(S)]
4151 Catch system calls. Arguments, which should be names of system
4152 calls or their numbers, mean catch only those syscalls. Without
4153 arguments, every syscall will be caught. When the inferior issues
4154 any of the specified syscalls, GDB will stop and announce the system
4155 call, both when it is called and when its call returns. This
4156 feature is currently available with a native GDB running on the
4157 Linux Kernel, under the following architectures: x86, x86_64,
4158 PowerPC and PowerPC64.
4160 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4162 Search memory for a sequence of bytes.
4164 maint set python print-stack
4165 maint show python print-stack
4166 Show a stack trace when an error is encountered in a Python script.
4169 Invoke CODE by passing it to the Python interpreter.
4174 These allow macros to be defined, undefined, and listed
4178 Show operating system information about processes.
4181 List the inferiors currently under GDB's control.
4184 Switch focus to inferior number NUM.
4187 Detach from inferior number NUM.
4190 Kill inferior number NUM.
4194 set spu stop-on-load
4195 show spu stop-on-load
4196 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4198 set spu auto-flush-cache
4199 show spu auto-flush-cache
4200 Control whether to automatically flush the software-managed cache
4201 during Cell/B.E. debugging.
4203 set sh calling-convention
4204 show sh calling-convention
4205 Control the calling convention used when calling SH target functions.
4208 show debug timestamp
4209 Control display of timestamps with GDB debugging output.
4211 set disassemble-next-line
4212 show disassemble-next-line
4213 Control display of disassembled source lines or instructions when
4216 set remote noack-packet
4217 show remote noack-packet
4218 Set/show the use of remote protocol QStartNoAckMode packet. See above
4219 under "New remote packets."
4221 set remote query-attached-packet
4222 show remote query-attached-packet
4223 Control use of remote protocol `qAttached' (query-attached) packet.
4225 set remote read-siginfo-object
4226 show remote read-siginfo-object
4227 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4230 set remote write-siginfo-object
4231 show remote write-siginfo-object
4232 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4235 set remote reverse-continue
4236 show remote reverse-continue
4237 Control use of remote protocol 'bc' (reverse-continue) packet.
4239 set remote reverse-step
4240 show remote reverse-step
4241 Control use of remote protocol 'bs' (reverse-step) packet.
4243 set displaced-stepping
4244 show displaced-stepping
4245 Control displaced stepping mode. Displaced stepping is a way to
4246 single-step over breakpoints without removing them from the debuggee.
4247 Also known as "out-of-line single-stepping".
4250 show debug displaced
4251 Control display of debugging info for displaced stepping.
4253 maint set internal-error
4254 maint show internal-error
4255 Control what GDB does when an internal error is detected.
4257 maint set internal-warning
4258 maint show internal-warning
4259 Control what GDB does when an internal warning is detected.
4264 Use a wrapper program to launch programs for debugging.
4266 set multiple-symbols (all|ask|cancel)
4267 show multiple-symbols
4268 The value of this variable can be changed to adjust the debugger behavior
4269 when an expression or a breakpoint location contains an ambiguous symbol
4270 name (an overloaded function name, for instance).
4272 set breakpoint always-inserted
4273 show breakpoint always-inserted
4274 Keep breakpoints always inserted in the target, as opposed to inserting
4275 them when resuming the target, and removing them when the target stops.
4276 This option can improve debugger performance on slow remote targets.
4278 set arm fallback-mode (arm|thumb|auto)
4279 show arm fallback-mode
4280 set arm force-mode (arm|thumb|auto)
4282 These commands control how ARM GDB determines whether instructions
4283 are ARM or Thumb. The default for both settings is auto, which uses
4284 the current CPSR value for instructions without symbols; previous
4285 versions of GDB behaved as if "set arm fallback-mode arm".
4287 set disable-randomization
4288 show disable-randomization
4289 Standalone programs run with the virtual address space randomization enabled
4290 by default on some platforms. This option keeps the addresses stable across
4291 multiple debugging sessions.
4295 Control whether other threads are stopped or not when some thread hits
4300 Requests that asynchronous execution is enabled in the target, if available.
4301 In this case, it's possible to resume target in the background, and interact
4302 with GDB while the target is running. "show target-async" displays the
4303 current state of asynchronous execution of the target.
4305 set target-wide-charset
4306 show target-wide-charset
4307 The target-wide-charset is the name of the character set that GDB
4308 uses when printing characters whose type is wchar_t.
4310 set tcp auto-retry (on|off)
4312 set tcp connect-timeout
4313 show tcp connect-timeout
4314 These commands allow GDB to retry failed TCP connections to a remote stub
4315 with a specified timeout period; this is useful if the stub is launched
4316 in parallel with GDB but may not be ready to accept connections immediately.
4318 set libthread-db-search-path
4319 show libthread-db-search-path
4320 Control list of directories which GDB will search for appropriate
4323 set schedule-multiple (on|off)
4324 show schedule-multiple
4325 Allow GDB to resume all threads of all processes or only threads of
4326 the current process.
4330 Use more aggressive caching for accesses to the stack. This improves
4331 performance of remote debugging (particularly backtraces) without
4332 affecting correctness.
4334 set interactive-mode (on|off|auto)
4335 show interactive-mode
4336 Control whether GDB runs in interactive mode (on) or not (off).
4337 When in interactive mode, GDB waits for the user to answer all
4338 queries. Otherwise, GDB does not wait and assumes the default
4339 answer. When set to auto (the default), GDB determines which
4340 mode to use based on the stdin settings.
4345 For program forks, this is replaced by the new more generic `info
4346 inferiors' command. To list checkpoints, you can still use the
4347 `info checkpoints' command, which was an alias for the `info forks'
4351 Replaced by the new `inferior' command. To switch between
4352 checkpoints, you can still use the `restart' command, which was an
4353 alias for the `fork' command.
4356 This is removed, since some targets don't have a notion of
4357 processes. To switch between processes, you can still use the
4358 `inferior' command using GDB's own inferior number.
4361 For program forks, this is replaced by the new more generic `kill
4362 inferior' command. To delete a checkpoint, you can still use the
4363 `delete checkpoint' command, which was an alias for the `delete
4367 For program forks, this is replaced by the new more generic `detach
4368 inferior' command. To detach a checkpoint, you can still use the
4369 `detach checkpoint' command, which was an alias for the `detach
4372 * New native configurations
4374 x86/x86_64 Darwin i[34567]86-*-darwin*
4376 x86_64 MinGW x86_64-*-mingw*
4380 Lattice Mico32 lm32-*
4381 x86 DICOS i[34567]86-*-dicos*
4382 x86_64 DICOS x86_64-*-dicos*
4385 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4386 (mingw32ce) debugging.
4392 These commands were actually not implemented on any target.
4394 *** Changes in GDB 6.8
4396 * New native configurations
4398 NetBSD/hppa hppa*-*netbsd*
4399 Xtensa GNU/Linux xtensa*-*-linux*
4403 NetBSD/hppa hppa*-*-netbsd*
4404 Xtensa GNU/Lunux xtensa*-*-linux*
4406 * Change in command line behavior -- corefiles vs. process ids.
4408 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4409 attaching to process NUMBER fails, GDB no longer attempts to open a
4410 core file named NUMBER. Attaching to a program using the -c option
4411 is no longer supported. Instead, use the '-p' or '--pid' options.
4413 * GDB can now be built as a native debugger for debugging Windows x86
4414 (mingw32) Portable Executable (PE) programs.
4416 * Pending breakpoints no longer change their number when their address
4419 * GDB now supports breakpoints with multiple locations,
4420 including breakpoints on C++ constructors, inside C++ templates,
4421 and in inlined functions.
4423 * GDB's ability to debug optimized code has been improved. GDB more
4424 accurately identifies function bodies and lexical blocks that occupy
4425 more than one contiguous range of addresses.
4427 * Target descriptions can now describe registers for PowerPC.
4429 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4430 registers on PowerPC targets.
4432 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4433 targets even when the libthread_db library is not available.
4435 * The GDB remote stub, gdbserver, now supports the new file transfer
4436 commands (remote put, remote get, and remote delete).
4438 * The GDB remote stub, gdbserver, now supports run and attach in
4439 extended-remote mode.
4441 * hppa*64*-*-hpux11* target broken
4442 The debugger is unable to start a program and fails with the following
4443 error: "Error trying to get information about dynamic linker".
4444 The gdb-6.7 release is also affected.
4446 * GDB now supports the --enable-targets= configure option to allow
4447 building a single GDB executable that supports multiple remote
4448 target architectures.
4450 * GDB now supports debugging C and C++ programs which use the
4451 Decimal Floating Point extension. In addition, the PowerPC target
4452 now has a set of pseudo-registers to inspect decimal float values
4453 stored in two consecutive float registers.
4455 * The -break-insert MI command can optionally create pending
4458 * Improved support for debugging Ada
4459 Many improvements to the Ada language support have been made. These
4461 - Better support for Ada2005 interface types
4462 - Improved handling of arrays and slices in general
4463 - Better support for Taft-amendment types
4464 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4466 - Improved command completion in Ada
4469 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4474 set print frame-arguments (all|scalars|none)
4475 show print frame-arguments
4476 The value of this variable can be changed to control which argument
4477 values should be printed by the debugger when displaying a frame.
4482 Transfer files to and from a remote target, and delete remote files.
4489 Transfer files to and from a remote target, and delete remote files.
4491 * New remote packets
4498 Open, close, read, write, and delete files on the remote system.
4501 Attach to an existing process on the remote system, in extended-remote
4505 Run a new process on the remote system, in extended-remote mode.
4507 *** Changes in GDB 6.7
4509 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4510 bfd, libiberty and opcodes, as revealed by static analysis donated by
4511 Coverity, Inc. (http://scan.coverity.com).
4513 * When looking up multiply-defined global symbols, GDB will now prefer the
4514 symbol definition in the current shared library if it was built using the
4515 -Bsymbolic linker option.
4517 * When the Text User Interface (TUI) is not configured, GDB will now
4518 recognize the -tui command-line option and print a message that the TUI
4521 * The GDB remote stub, gdbserver, now has lower overhead for high
4522 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4524 * GDB for MIPS targets now autodetects whether a remote target provides
4525 32-bit or 64-bit register values.
4527 * Support for C++ member pointers has been improved.
4529 * GDB now understands XML target descriptions, which specify the
4530 target's overall architecture. GDB can read a description from
4531 a local file or over the remote serial protocol.
4533 * Vectors of single-byte data use a new integer type which is not
4534 automatically displayed as character or string data.
4536 * The /s format now works with the print command. It displays
4537 arrays of single-byte integers and pointers to single-byte integers
4540 * Target descriptions can now describe target-specific registers,
4541 for architectures which have implemented the support (currently
4542 only ARM, M68K, and MIPS).
4544 * GDB and the GDB remote stub, gdbserver, now support the XScale
4547 * The GDB remote stub, gdbserver, has been updated to support
4548 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4549 has been rewritten to use the standard GDB remote protocol.
4551 * GDB can now step into C++ functions which are called through thunks.
4553 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4555 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4556 layout. It also supports a TextSeg= and DataSeg= response when only
4557 segment base addresses (rather than offsets) are available.
4559 * The /i format now outputs any trailing branch delay slot instructions
4560 immediately following the last instruction within the count specified.
4562 * The GDB remote protocol "T" stop reply packet now supports a
4563 "library" response. Combined with the new "qXfer:libraries:read"
4564 packet, this response allows GDB to debug shared libraries on targets
4565 where the operating system manages the list of loaded libraries (e.g.
4566 Windows and SymbianOS).
4568 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4569 (DLLs) on Windows and Windows CE targets.
4571 * GDB now supports a faster verification that a .debug file matches its binary
4572 according to its build-id signature, if the signature is present.
4578 Enable or disable hardware flow control (RTS/CTS) on the serial port
4579 when debugging using remote targets.
4581 set mem inaccessible-by-default
4582 show mem inaccessible-by-default
4583 If the target supplies a memory map, for instance via the remote
4584 protocol's "qXfer:memory-map:read" packet, setting this variable
4585 prevents GDB from accessing memory outside the memory map. This
4586 is useful for targets with memory mapped registers or which react
4587 badly to accesses of unmapped address space.
4589 set breakpoint auto-hw
4590 show breakpoint auto-hw
4591 If the target supplies a memory map, for instance via the remote
4592 protocol's "qXfer:memory-map:read" packet, setting this variable
4593 lets GDB use hardware breakpoints automatically for memory regions
4594 where it can not use software breakpoints. This covers both the
4595 "break" command and internal breakpoints used for other commands
4596 including "next" and "finish".
4599 catch exception unhandled
4600 Stop the program execution when Ada exceptions are raised.
4603 Stop the program execution when an Ada assertion failed.
4607 Set an alternate system root for target files. This is a more
4608 general version of "set solib-absolute-prefix", which is now
4609 an alias to "set sysroot".
4612 Provide extended SPU facility status information. This set of
4613 commands is available only when debugging the Cell/B.E. SPU
4616 * New native configurations
4618 OpenBSD/sh sh*-*openbsd*
4621 unset tdesc filename
4623 Use the specified local file as an XML target description, and do
4624 not query the target for its built-in description.
4628 OpenBSD/sh sh*-*-openbsd*
4629 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4630 Toshiba Media Processor mep-elf
4632 * New remote packets
4635 Ignore the specified signals; pass them directly to the debugged program
4636 without stopping other threads or reporting them to GDB.
4638 qXfer:features:read:
4639 Read an XML target description from the target, which describes its
4644 Read or write contents of an spufs file on the target system. These
4645 packets are available only on the Cell/B.E. SPU architecture.
4647 qXfer:libraries:read:
4648 Report the loaded shared libraries. Combined with new "T" packet
4649 response, this packet allows GDB to debug shared libraries on
4650 targets where the operating system manages the list of loaded
4651 libraries (e.g. Windows and SymbianOS).
4655 Support for these obsolete configurations has been removed.
4663 i[34567]86-*-lynxos*
4664 i[34567]86-*-netware*
4665 i[34567]86-*-sco3.2v5*
4666 i[34567]86-*-sco3.2v4*
4668 i[34567]86-*-sysv4.2*
4671 i[34567]86-*-unixware2*
4672 i[34567]86-*-unixware*
4681 * Other removed features
4688 Various m68k-only ROM monitors.
4695 Various Renesas ROM monitors and debugging interfaces for SH and
4700 Support for a Macraigor serial interface to on-chip debugging.
4701 GDB does not directly support the newer parallel or USB
4706 A debug information format. The predecessor to DWARF 2 and
4707 DWARF 3, which are still supported.
4709 Support for the HP aCC compiler on HP-UX/PA-RISC
4711 SOM-encapsulated symbolic debugging information, automatic
4712 invocation of pxdb, and the aCC custom C++ ABI. This does not
4713 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4714 with aCC can still be debugged on an assembly level.
4716 MIPS ".pdr" sections
4718 A MIPS-specific format used to describe stack frame layout
4719 in debugging information.
4723 GDB could work with an older version of Guile to debug
4724 the interpreter and Scheme programs running in it.
4726 set mips stack-arg-size
4727 set mips saved-gpreg-size
4729 Use "set mips abi" to control parameter passing for MIPS.
4731 *** Changes in GDB 6.6
4736 Cell Broadband Engine SPU spu-elf
4738 * GDB can now be configured as a cross-debugger targeting native Windows
4739 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4740 running on a Windows system over TCP/IP to debug Windows programs.
4742 * The GDB remote stub, gdbserver, has been updated to support Windows and
4743 Cygwin debugging. Both single-threaded and multi-threaded programs are
4746 * The "set trust-readonly-sections" command works again. This command was
4747 broken in GDB 6.3, 6.4, and 6.5.
4749 * The "load" command now supports writing to flash memory, if the remote
4750 stub provides the required support.
4752 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4753 longer requires symbolic debug information (e.g. DWARF-2).
4758 unset substitute-path
4759 show substitute-path
4760 Manage a list of substitution rules that GDB uses to rewrite the name
4761 of the directories where the sources are located. This can be useful
4762 for instance when the sources were moved to a different location
4763 between compilation and debugging.
4767 Print each CLI command as it is executed. Each command is prefixed with
4768 a number of `+' symbols representing the nesting depth.
4769 The source command now has a `-v' option to enable the same feature.
4773 The ARM Demon monitor support (RDP protocol, "target rdp").
4775 Kernel Object Display, an embedded debugging feature which only worked with
4776 an obsolete version of Cisco IOS.
4778 The 'set download-write-size' and 'show download-write-size' commands.
4780 * New remote packets
4783 Tell a stub about GDB client features, and request remote target features.
4784 The first feature implemented is PacketSize, which allows the target to
4785 specify the size of packets it can handle - to minimize the number of
4786 packets required and improve performance when connected to a remote
4790 Fetch an OS auxilliary vector from the remote stub. This packet is a
4791 more efficient replacement for qPart:auxv:read.
4793 qXfer:memory-map:read:
4794 Fetch a memory map from the remote stub, including information about
4795 RAM, ROM, and flash memory devices.
4800 Erase and program a flash memory device.
4802 * Removed remote packets
4805 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4806 used it, and only gdbserver implemented it.
4808 *** Changes in GDB 6.5
4812 Renesas M32C/M16C m32c-elf
4814 Morpho Technologies ms1 ms1-elf
4818 init-if-undefined Initialize a convenience variable, but
4819 only if it doesn't already have a value.
4821 The following commands are presently only implemented for native GNU/Linux:
4823 checkpoint Save a snapshot of the program state.
4825 restart <n> Return the program state to a
4826 previously saved state.
4828 info checkpoints List currently saved checkpoints.
4830 delete-checkpoint <n> Delete a previously saved checkpoint.
4832 set|show detach-on-fork Tell gdb whether to detach from a newly
4833 forked process, or to keep debugging it.
4835 info forks List forks of the user program that
4836 are available to be debugged.
4838 fork <n> Switch to debugging one of several
4839 forks of the user program that are
4840 available to be debugged.
4842 delete-fork <n> Delete a fork from the list of forks
4843 that are available to be debugged (and
4844 kill the forked process).
4846 detach-fork <n> Delete a fork from the list of forks
4847 that are available to be debugged (and
4848 allow the process to continue).
4852 Morpho Technologies ms2 ms1-elf
4854 * Improved Windows host support
4856 GDB now builds as a cross debugger hosted on i686-mingw32, including
4857 native console support, and remote communications using either
4858 network sockets or serial ports.
4860 * Improved Modula-2 language support
4862 GDB can now print most types in the Modula-2 syntax. This includes:
4863 basic types, set types, record types, enumerated types, range types,
4864 pointer types and ARRAY types. Procedure var parameters are correctly
4865 printed and hexadecimal addresses and character constants are also
4866 written in the Modula-2 syntax. Best results can be obtained by using
4867 GNU Modula-2 together with the -gdwarf-2 command line option.
4871 The ARM rdi-share module.
4873 The Netware NLM debug server.
4875 *** Changes in GDB 6.4
4877 * New native configurations
4879 OpenBSD/arm arm*-*-openbsd*
4880 OpenBSD/mips64 mips64-*-openbsd*
4884 Morpho Technologies ms1 ms1-elf
4886 * New command line options
4888 --batch-silent As for --batch, but totally silent.
4889 --return-child-result The debugger will exist with the same value
4890 the child (debugged) program exited with.
4891 --eval-command COMMAND, -ex COMMAND
4892 Execute a single GDB CLI command. This may be
4893 specified multiple times and in conjunction
4894 with the --command (-x) option.
4896 * Deprecated commands removed
4898 The following commands, that were deprecated in 2000, have been
4902 set|show arm disassembly-flavor set|show arm disassembler
4903 othernames set arm disassembler
4904 set|show remotedebug set|show debug remote
4905 set|show archdebug set|show debug arch
4906 set|show eventdebug set|show debug event
4909 * New BSD user-level threads support
4911 It is now possible to debug programs using the user-level threads
4912 library on OpenBSD and FreeBSD. Currently supported (target)
4915 FreeBSD/amd64 x86_64-*-freebsd*
4916 FreeBSD/i386 i386-*-freebsd*
4917 OpenBSD/i386 i386-*-openbsd*
4919 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4920 are not yet supported.
4922 * New support for Matsushita MN10300 w/sim added
4923 (Work in progress). mn10300-elf.
4925 * REMOVED configurations and files
4927 VxWorks and the XDR protocol *-*-vxworks
4928 Motorola MCORE mcore-*-*
4929 National Semiconductor NS32000 ns32k-*-*
4931 * New "set print array-indexes" command
4933 After turning this setting "on", GDB prints the index of each element
4934 when displaying arrays. The default is "off" to preserve the previous
4937 * VAX floating point support
4939 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4941 * User-defined command support
4943 In addition to using $arg0..$arg9 for argument passing, it is now possible
4944 to use $argc to determine now many arguments have been passed. See the
4945 section on user-defined commands in the user manual for more information.
4947 *** Changes in GDB 6.3:
4949 * New command line option
4951 GDB now accepts -l followed by a number to set the timeout for remote
4954 * GDB works with GCC -feliminate-dwarf2-dups
4956 GDB now supports a more compact representation of DWARF-2 debug
4957 information using DW_FORM_ref_addr references. These are produced
4958 by GCC with the option -feliminate-dwarf2-dups and also by some
4959 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4960 to use -feliminate-dwarf2-dups.
4962 * Internationalization
4964 When supported by the host system, GDB will be built with
4965 internationalization (libintl). The task of marking up the sources is
4966 continued, we're looking forward to our first translation.
4970 Initial support for debugging programs compiled with the GNAT
4971 implementation of the Ada programming language has been integrated
4972 into GDB. In this release, support is limited to expression evaluation.
4974 * New native configurations
4976 GNU/Linux/m32r m32r-*-linux-gnu
4980 GDB's remote protocol now includes support for the 'p' packet. This
4981 packet is used to fetch individual registers from a remote inferior.
4983 * END-OF-LIFE registers[] compatibility module
4985 GDB's internal register infrastructure has been completely rewritten.
4986 The new infrastructure making possible the implementation of key new
4987 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4990 GDB 6.3 will be the last release to include the the registers[]
4991 compatibility module that allowed out-of-date configurations to
4992 continue to work. This change directly impacts the following
5002 powerpc bdm protocol
5004 Unless there is activity to revive these configurations, they will be
5005 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5007 * OBSOLETE configurations and files
5009 Configurations that have been declared obsolete in this release have
5010 been commented out. Unless there is activity to revive these
5011 configurations, the next release of GDB will have their sources
5012 permanently REMOVED.
5021 *** Changes in GDB 6.2.1:
5023 * MIPS `break main; run' gave an heuristic-fence-post warning
5025 When attempting to run even a simple program, a warning about
5026 heuristic-fence-post being hit would be reported. This problem has
5029 * MIPS IRIX 'long double' crashed GDB
5031 When examining a long double variable, GDB would get a segmentation
5032 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5033 IRIX long double values).
5037 A bug in the VAX stack code was causing problems with the "next"
5038 command. This problem has been fixed.
5040 *** Changes in GDB 6.2:
5042 * Fix for ``many threads''
5044 On GNU/Linux systems that use the NPTL threads library, a program
5045 rapidly creating and deleting threads would confuse GDB leading to the
5048 ptrace: No such process.
5049 thread_db_get_info: cannot get thread info: generic error
5051 This problem has been fixed.
5053 * "-async" and "-noasync" options removed.
5055 Support for the broken "-noasync" option has been removed (it caused
5058 * New ``start'' command.
5060 This command runs the program until the begining of the main procedure.
5062 * New BSD Kernel Data Access Library (libkvm) interface
5064 Using ``target kvm'' it is now possible to debug kernel core dumps and
5065 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5066 platforms. Currently supported (native-only) configurations are:
5068 FreeBSD/amd64 x86_64-*-freebsd*
5069 FreeBSD/i386 i?86-*-freebsd*
5070 NetBSD/i386 i?86-*-netbsd*
5071 NetBSD/m68k m68*-*-netbsd*
5072 NetBSD/sparc sparc-*-netbsd*
5073 OpenBSD/amd64 x86_64-*-openbsd*
5074 OpenBSD/i386 i?86-*-openbsd*
5075 OpenBSD/m68k m68*-openbsd*
5076 OpenBSD/sparc sparc-*-openbsd*
5078 * Signal trampoline code overhauled
5080 Many generic problems with GDB's signal handling code have been fixed.
5081 These include: backtraces through non-contiguous stacks; recognition
5082 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5083 call; backtrace through a signal trampoline; step into and out of
5084 signal handlers; and single-stepping in the signal trampoline.
5086 Please note that kernel bugs are a limiting factor here. These
5087 features have been shown to work on an s390 GNU/Linux system that
5088 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5090 * Cygwin support for DWARF 2 added.
5092 * New native configurations
5094 GNU/Linux/hppa hppa*-*-linux*
5095 OpenBSD/hppa hppa*-*-openbsd*
5096 OpenBSD/m68k m68*-*-openbsd*
5097 OpenBSD/m88k m88*-*-openbsd*
5098 OpenBSD/powerpc powerpc-*-openbsd*
5099 NetBSD/vax vax-*-netbsd*
5100 OpenBSD/vax vax-*-openbsd*
5102 * END-OF-LIFE frame compatibility module
5104 GDB's internal frame infrastructure has been completely rewritten.
5105 The new infrastructure making it possible to support key new features
5106 including DWARF 2 Call Frame Information. To aid in the task of
5107 migrating old configurations to this new infrastructure, a
5108 compatibility module, that allowed old configurations to continue to
5109 work, was also included.
5111 GDB 6.2 will be the last release to include this frame compatibility
5112 module. This change directly impacts the following configurations:
5122 Unless there is activity to revive these configurations, they will be
5123 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5125 * REMOVED configurations and files
5127 Sun 3, running SunOS 3 m68*-*-sunos3*
5128 Sun 3, running SunOS 4 m68*-*-sunos4*
5129 Sun 2, running SunOS 3 m68000-*-sunos3*
5130 Sun 2, running SunOS 4 m68000-*-sunos4*
5131 Motorola 680x0 running LynxOS m68*-*-lynxos*
5132 AT&T 3b1/Unix pc m68*-att-*
5133 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5134 decstation mips-dec-* mips-little-*
5135 riscos mips-*-riscos* mips-*-sysv*
5136 sonymips mips-sony-*
5137 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5139 *** Changes in GDB 6.1.1:
5141 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5143 The TUI (Text-mode User Interface) is now built as part of a default
5144 GDB configuration. It is enabled by either selecting the TUI with the
5145 command line option "-i=tui" or by running the separate "gdbtui"
5146 program. For more information on the TUI, see the manual "Debugging
5149 * Pending breakpoint support (also included in GDB 6.1)
5151 Support has been added to allow you to specify breakpoints in shared
5152 libraries that have not yet been loaded. If a breakpoint location
5153 cannot be found, and the "breakpoint pending" option is set to auto,
5154 GDB queries you if you wish to make the breakpoint pending on a future
5155 shared-library load. If and when GDB resolves the breakpoint symbol,
5156 the pending breakpoint is removed as one or more regular breakpoints
5159 Pending breakpoints are very useful for GCJ Java debugging.
5161 * Fixed ISO-C build problems
5163 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5164 non ISO-C code that stopped them being built using a more strict ISO-C
5165 compiler (e.g., IBM's C compiler).
5167 * Fixed build problem on IRIX 5
5169 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5170 wasn't able to compile compile on an IRIX 5 system.
5172 * Added execute permission to gdb/gdbserver/configure
5174 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5175 permission. This bug would cause configure to fail on a number of
5176 systems (Solaris, IRIX). Ref: server/519.
5178 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5180 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5181 has been updated to use constant array sizes.
5183 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5185 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5186 its generated DWARF Call Frame Info. This encoding was causing GDB to
5187 panic, that panic has been fixed. Ref: gdb/1628.
5189 * Fixed a problem when examining parameters in shared library code.
5191 When examining parameters in optimized shared library code generated
5192 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5193 not available''. GDB now correctly displays the variable's value.
5195 *** Changes in GDB 6.1:
5197 * Removed --with-mmalloc
5199 Support for the mmalloc memory manager has been removed, as it
5200 conflicted with the internal gdb byte cache.
5202 * Changes in AMD64 configurations
5204 The AMD64 target now includes the %cs and %ss registers. As a result
5205 the AMD64 remote protocol has changed; this affects the floating-point
5206 and SSE registers. If you rely on those registers for your debugging,
5207 you should upgrade gdbserver on the remote side.
5209 * Revised SPARC target
5211 The SPARC target has been completely revised, incorporating the
5212 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5213 support for LynxOS and SunOS 4 has been dropped. Calling functions
5214 from within GDB on operating systems with a non-executable stack
5215 (Solaris, OpenBSD) now works.
5219 GDB has a new C++ demangler which does a better job on the mangled
5220 names generated by current versions of g++. It also runs faster, so
5221 with this and other changes gdb should now start faster on large C++
5224 * DWARF 2 Location Expressions
5226 GDB support for location expressions has been extended to support function
5227 arguments and frame bases. Older versions of GDB could crash when they
5230 * C++ nested types and namespaces
5232 GDB's support for nested types and namespaces in C++ has been
5233 improved, especially if you use the DWARF 2 debugging format. (This
5234 is the default for recent versions of GCC on most platforms.)
5235 Specifically, if you have a class "Inner" defined within a class or
5236 namespace "Outer", then GDB realizes that the class's name is
5237 "Outer::Inner", not simply "Inner". This should greatly reduce the
5238 frequency of complaints about not finding RTTI symbols. In addition,
5239 if you are stopped at inside of a function defined within a namespace,
5240 GDB modifies its name lookup accordingly.
5242 * New native configurations
5244 NetBSD/amd64 x86_64-*-netbsd*
5245 OpenBSD/amd64 x86_64-*-openbsd*
5246 OpenBSD/alpha alpha*-*-openbsd*
5247 OpenBSD/sparc sparc-*-openbsd*
5248 OpenBSD/sparc64 sparc64-*-openbsd*
5250 * New debugging protocols
5252 M32R with SDI protocol m32r-*-elf*
5254 * "set prompt-escape-char" command deleted.
5256 The command "set prompt-escape-char" has been deleted. This command,
5257 and its very obscure effet on GDB's prompt, was never documented,
5258 tested, nor mentioned in the NEWS file.
5260 * OBSOLETE configurations and files
5262 Configurations that have been declared obsolete in this release have
5263 been commented out. Unless there is activity to revive these
5264 configurations, the next release of GDB will have their sources
5265 permanently REMOVED.
5267 Sun 3, running SunOS 3 m68*-*-sunos3*
5268 Sun 3, running SunOS 4 m68*-*-sunos4*
5269 Sun 2, running SunOS 3 m68000-*-sunos3*
5270 Sun 2, running SunOS 4 m68000-*-sunos4*
5271 Motorola 680x0 running LynxOS m68*-*-lynxos*
5272 AT&T 3b1/Unix pc m68*-att-*
5273 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5274 decstation mips-dec-* mips-little-*
5275 riscos mips-*-riscos* mips-*-sysv*
5276 sonymips mips-sony-*
5277 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5279 * REMOVED configurations and files
5281 SGI Irix-4.x mips-sgi-irix4 or iris4
5282 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5283 Z8000 simulator z8k-zilog-none or z8ksim
5284 Matsushita MN10200 w/simulator mn10200-*-*
5285 H8/500 simulator h8500-hitachi-hms or h8500hms
5286 HP/PA running BSD hppa*-*-bsd*
5287 HP/PA running OSF/1 hppa*-*-osf*
5288 HP/PA Pro target hppa*-*-pro*
5289 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5290 386BSD i[3456]86-*-bsd*
5291 Sequent family i[3456]86-sequent-sysv4*
5292 i[3456]86-sequent-sysv*
5293 i[3456]86-sequent-bsd*
5294 SPARC running LynxOS sparc-*-lynxos*
5295 SPARC running SunOS 4 sparc-*-sunos4*
5296 Tsqware Sparclet sparclet-*-*
5297 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5299 *** Changes in GDB 6.0:
5303 Support for debugging the Objective-C programming language has been
5304 integrated into GDB.
5306 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5308 DWARF 2's Call Frame Information makes available compiler generated
5309 information that more exactly describes the program's run-time stack.
5310 By using this information, GDB is able to provide more robust stack
5313 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5314 have been updated to use a new backtrace mechanism which includes
5315 DWARF 2 CFI support.
5319 GDB's remote protocol has been extended to include support for hosted
5320 file I/O (where the remote target uses GDB's file system). See GDB's
5321 remote protocol documentation for details.
5323 * All targets using the new architecture framework.
5325 All of GDB's targets have been updated to use the new internal
5326 architecture framework. The way is now open for future GDB releases
5327 to include cross-architecture native debugging support (i386 on amd64,
5330 * GNU/Linux's Thread Local Storage (TLS)
5332 GDB now includes support for for the GNU/Linux implementation of
5333 per-thread variables.
5335 * GNU/Linux's Native POSIX Thread Library (NPTL)
5337 GDB's thread code has been updated to work with either the new
5338 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5340 * Separate debug info.
5342 GDB, in conjunction with BINUTILS, now supports a mechanism for
5343 automatically loading debug information from a separate file. Instead
5344 of shipping full debug and non-debug versions of system libraries,
5345 system integrators can now instead ship just the stripped libraries
5346 and optional debug files.
5348 * DWARF 2 Location Expressions
5350 DWARF 2 Location Expressions allow the compiler to more completely
5351 describe the location of variables (even in optimized code) to the
5354 GDB now includes preliminary support for location expressions (support
5355 for DW_OP_piece is still missing).
5359 A number of long standing bugs that caused GDB to die while starting a
5360 Java application have been fixed. GDB's Java support is now
5361 considered "useable".
5363 * GNU/Linux support for fork, vfork, and exec.
5365 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5366 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5369 * GDB supports logging output to a file
5371 There are two new commands, "set logging" and "show logging", which can be
5372 used to capture GDB's output to a file.
5374 * The meaning of "detach" has changed for gdbserver
5376 The "detach" command will now resume the application, as documented. To
5377 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5380 * d10v, m68hc11 `regs' command deprecated
5382 The `info registers' command has been updated so that it displays the
5383 registers using a format identical to the old `regs' command.
5387 A new command, "maint set profile on/off", has been added. This command can
5388 be used to enable or disable profiling while running GDB, to profile a
5389 session or a set of commands. In addition there is a new configure switch,
5390 "--enable-profiling", which will cause GDB to be compiled with profiling
5391 data, for more informative profiling results.
5393 * Default MI syntax changed to "mi2".
5395 The default MI (machine interface) syntax, enabled by the command line
5396 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5397 "mi1", can be enabled by specifying the option "-i=mi1".
5399 Support for the original "mi0" syntax (included in GDB 5.0) has been
5402 Fix for gdb/192: removed extraneous space when displaying frame level.
5403 Fix for gdb/672: update changelist is now output in mi list format.
5404 Fix for gdb/702: a -var-assign that updates the value now shows up
5405 in a subsequent -var-update.
5407 * New native configurations.
5409 FreeBSD/amd64 x86_64-*-freebsd*
5411 * Multi-arched targets.
5413 HP/PA HPUX11 hppa*-*-hpux*
5414 Renesas M32R/D w/simulator m32r-*-elf*
5416 * OBSOLETE configurations and files
5418 Configurations that have been declared obsolete in this release have
5419 been commented out. Unless there is activity to revive these
5420 configurations, the next release of GDB will have their sources
5421 permanently REMOVED.
5423 Z8000 simulator z8k-zilog-none or z8ksim
5424 Matsushita MN10200 w/simulator mn10200-*-*
5425 H8/500 simulator h8500-hitachi-hms or h8500hms
5426 HP/PA running BSD hppa*-*-bsd*
5427 HP/PA running OSF/1 hppa*-*-osf*
5428 HP/PA Pro target hppa*-*-pro*
5429 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5430 Sequent family i[3456]86-sequent-sysv4*
5431 i[3456]86-sequent-sysv*
5432 i[3456]86-sequent-bsd*
5433 Tsqware Sparclet sparclet-*-*
5434 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5436 * REMOVED configurations and files
5439 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5440 IBM AIX PS/2 i[3456]86-*-aix
5441 i386 running Mach 3.0 i[3456]86-*-mach3*
5442 i386 running Mach i[3456]86-*-mach*
5443 i386 running OSF/1 i[3456]86-*osf1mk*
5444 HP/Apollo 68k Family m68*-apollo*-sysv*,
5446 m68*-hp-bsd*, m68*-hp-hpux*
5447 Argonaut Risc Chip (ARC) arc-*-*
5448 Mitsubishi D30V d30v-*-*
5449 Fujitsu FR30 fr30-*-elf*
5450 OS/9000 i[34]86-*-os9k
5451 I960 with MON960 i960-*-coff
5453 * MIPS $fp behavior changed
5455 The convenience variable $fp, for the MIPS, now consistently returns
5456 the address of the current frame's base. Previously, depending on the
5457 context, $fp could refer to either $sp or the current frame's base
5458 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5459 The GNU Source-Level Debugger''.
5461 *** Changes in GDB 5.3:
5463 * GNU/Linux shared library multi-threaded performance improved.
5465 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5466 `/proc', in preference to `ptrace' for memory reads. This may result
5467 in an improvement in the start-up time of multi-threaded, shared
5468 library applications when run under GDB. One GDB user writes: ``loads
5469 shared libs like mad''.
5471 * ``gdbserver'' now supports multi-threaded applications on some targets
5473 Support for debugging multi-threaded applications which use
5474 the GNU/Linux LinuxThreads package has been added for
5475 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5476 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5478 * GDB now supports C/C++ preprocessor macros.
5480 GDB now expands preprocessor macro invocations in C/C++ expressions,
5481 and provides various commands for showing macro definitions and how
5484 The new command `macro expand EXPRESSION' expands any macro
5485 invocations in expression, and shows the result.
5487 The new command `show macro MACRO-NAME' shows the definition of the
5488 macro named MACRO-NAME, and where it was defined.
5490 Most compilers don't include information about macros in the debugging
5491 information by default. In GCC 3.1, for example, you need to compile
5492 your program with the options `-gdwarf-2 -g3'. If the macro
5493 information is present in the executable, GDB will read it.
5495 * Multi-arched targets.
5497 DEC Alpha (partial) alpha*-*-*
5498 DEC VAX (partial) vax-*-*
5500 National Semiconductor NS32000 (partial) ns32k-*-*
5501 Motorola 68000 (partial) m68k-*-*
5502 Motorola MCORE mcore-*-*
5506 Fujitsu FRV architecture added by Red Hat frv*-*-*
5509 * New native configurations
5511 Alpha NetBSD alpha*-*-netbsd*
5512 SH NetBSD sh*-*-netbsdelf*
5513 MIPS NetBSD mips*-*-netbsd*
5514 UltraSPARC NetBSD sparc64-*-netbsd*
5516 * OBSOLETE configurations and files
5518 Configurations that have been declared obsolete in this release have
5519 been commented out. Unless there is activity to revive these
5520 configurations, the next release of GDB will have their sources
5521 permanently REMOVED.
5523 Mitsubishi D30V d30v-*-*
5524 OS/9000 i[34]86-*-os9k
5525 IBM AIX PS/2 i[3456]86-*-aix
5526 Fujitsu FR30 fr30-*-elf*
5527 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5528 Argonaut Risc Chip (ARC) arc-*-*
5529 i386 running Mach 3.0 i[3456]86-*-mach3*
5530 i386 running Mach i[3456]86-*-mach*
5531 i386 running OSF/1 i[3456]86-*osf1mk*
5532 HP/Apollo 68k Family m68*-apollo*-sysv*,
5534 m68*-hp-bsd*, m68*-hp-hpux*
5535 I960 with MON960 i960-*-coff
5537 * OBSOLETE languages
5539 CHILL, a Pascal like language used by telecommunications companies.
5541 * REMOVED configurations and files
5543 AMD 29k family via UDI a29k-amd-udi, udi29k
5544 A29K VxWorks a29k-*-vxworks
5545 AMD 29000 embedded, using EBMON a29k-none-none
5546 AMD 29000 embedded with COFF a29k-none-coff
5547 AMD 29000 embedded with a.out a29k-none-aout
5549 testsuite/gdb.hp/gdb.threads-hp/ directory
5551 * New command "set max-user-call-depth <nnn>"
5553 This command allows the user to limit the call depth of user-defined
5554 commands. The default is 1024.
5556 * Changes in FreeBSD/i386 native debugging.
5558 Support for the "generate-core-file" has been added.
5560 * New commands "dump", "append", and "restore".
5562 These commands allow data to be copied from target memory
5563 to a bfd-format or binary file (dump and append), and back
5564 from a file into memory (restore).
5566 * Improved "next/step" support on multi-processor Alpha Tru64.
5568 The previous single-step mechanism could cause unpredictable problems,
5569 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5570 of a software single-step mechanism prevents this.
5572 *** Changes in GDB 5.2.1:
5580 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5581 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5582 Fix, by Joel Brobecker imported from mainline.
5584 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5585 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5586 Fix, by Fred Fish, imported from mainline.
5588 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5589 Surprisingly enough, it works now.
5590 By Michal Ludvig, imported from mainline.
5592 i386 hardware watchpoint support:
5593 avoid misses on second run for some targets.
5594 By Pierre Muller, imported from mainline.
5596 *** Changes in GDB 5.2:
5598 * New command "set trust-readonly-sections on[off]".
5600 This command is a hint that tells gdb that read-only sections
5601 really are read-only (ie. that their contents will not change).
5602 In this mode, gdb will go to the object file rather than the
5603 target to read memory from read-only sections (such as ".text").
5604 This can be a significant performance improvement on some
5605 (notably embedded) targets.
5607 * New command "generate-core-file" (or "gcore").
5609 This new gdb command allows the user to drop a core file of the child
5610 process state at any time. So far it's been implemented only for
5611 GNU/Linux and Solaris, but should be relatively easily ported to other
5612 hosts. Argument is core file name (defaults to core.<pid>).
5614 * New command line option
5616 GDB now accepts --pid or -p followed by a process id.
5618 * Change in command line behavior -- corefiles vs. process ids.
5620 There is a subtle behavior in the way in which GDB handles
5621 command line arguments. The first non-flag argument is always
5622 a program to debug, but the second non-flag argument may either
5623 be a corefile or a process id. Previously, GDB would attempt to
5624 open the second argument as a corefile, and if that failed, would
5625 issue a superfluous error message and then attempt to attach it as
5626 a process. Now, if the second argument begins with a non-digit,
5627 it will be treated as a corefile. If it begins with a digit,
5628 GDB will attempt to attach it as a process, and if no such process
5629 is found, will then attempt to open it as a corefile.
5631 * Changes in ARM configurations.
5633 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5634 configuration is fully multi-arch.
5636 * New native configurations
5638 ARM NetBSD arm*-*-netbsd*
5639 x86 OpenBSD i[3456]86-*-openbsd*
5640 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5641 Sparc64 running FreeBSD sparc64-*-freebsd*
5645 Sanyo XStormy16 xstormy16-elf
5647 * OBSOLETE configurations and files
5649 Configurations that have been declared obsolete in this release have
5650 been commented out. Unless there is activity to revive these
5651 configurations, the next release of GDB will have their sources
5652 permanently REMOVED.
5654 AMD 29k family via UDI a29k-amd-udi, udi29k
5655 A29K VxWorks a29k-*-vxworks
5656 AMD 29000 embedded, using EBMON a29k-none-none
5657 AMD 29000 embedded with COFF a29k-none-coff
5658 AMD 29000 embedded with a.out a29k-none-aout
5660 testsuite/gdb.hp/gdb.threads-hp/ directory
5662 * REMOVED configurations and files
5664 TI TMS320C80 tic80-*-*
5666 PowerPC Solaris powerpcle-*-solaris*
5667 PowerPC Windows NT powerpcle-*-cygwin32
5668 PowerPC Netware powerpc-*-netware*
5669 Harris/CXUX m88k m88*-harris-cxux*
5670 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5671 ns32k-utek-sysv* ns32k-utek-*
5672 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5673 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5674 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5675 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5676 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5678 * Changes to command line processing
5680 The new `--args' feature can be used to specify command-line arguments
5681 for the inferior from gdb's command line.
5683 * Changes to key bindings
5685 There is a new `operate-and-get-next' function bound to `C-o'.
5687 *** Changes in GDB 5.1.1
5689 Fix compile problem on DJGPP.
5691 Fix a problem with floating-point registers on the i386 being
5694 Fix to stop GDB crashing on .debug_str debug info.
5696 Numerous documentation fixes.
5698 Numerous testsuite fixes.
5700 *** Changes in GDB 5.1:
5702 * New native configurations
5704 Alpha FreeBSD alpha*-*-freebsd*
5705 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5706 MIPS GNU/Linux mips*-*-linux*
5707 MIPS SGI Irix 6.x mips*-sgi-irix6*
5708 ia64 AIX ia64-*-aix*
5709 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5713 Motorola 68HC11 and 68HC12 m68hc11-elf
5715 UltraSparc running GNU/Linux sparc64-*-linux*
5717 * OBSOLETE configurations and files
5719 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5720 Harris/CXUX m88k m88*-harris-cxux*
5721 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5722 ns32k-utek-sysv* ns32k-utek-*
5723 TI TMS320C80 tic80-*-*
5725 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5726 PowerPC Solaris powerpcle-*-solaris*
5727 PowerPC Windows NT powerpcle-*-cygwin32
5728 PowerPC Netware powerpc-*-netware*
5729 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5730 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5731 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5732 Apple Macintosh (MPW) host N/A
5734 stuff.c (Program to stuff files into a specially prepared space in kdb)
5735 kdb-start.c (Main loop for the standalone kernel debugger)
5737 Configurations that have been declared obsolete in this release have
5738 been commented out. Unless there is activity to revive these
5739 configurations, the next release of GDB will have their sources
5740 permanently REMOVED.
5742 * REMOVED configurations and files
5744 Altos 3068 m68*-altos-*
5745 Convex c1-*-*, c2-*-*
5747 ARM RISCix arm-*-* (as host)
5751 * GDB has been converted to ISO C.
5753 GDB's source code has been converted to ISO C. In particular, the
5754 sources are fully protoized, and rely on standard headers being
5759 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5761 * The MI enabled by default.
5763 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5764 revised and enabled by default. Packages which use GDB as a debugging
5765 engine behind a UI or another front end are encouraged to switch to
5766 using the GDB/MI interface, instead of the old annotations interface
5767 which is now deprecated.
5769 * Support for debugging Pascal programs.
5771 GDB now includes support for debugging Pascal programs. The following
5772 main features are supported:
5774 - Pascal-specific data types such as sets;
5776 - automatic recognition of Pascal sources based on file-name
5779 - Pascal-style display of data types, variables, and functions;
5781 - a Pascal expression parser.
5783 However, some important features are not yet supported.
5785 - Pascal string operations are not supported at all;
5787 - there are some problems with boolean types;
5789 - Pascal type hexadecimal constants are not supported
5790 because they conflict with the internal variables format;
5792 - support for Pascal objects and classes is not full yet;
5794 - unlike Pascal, GDB is case-sensitive for symbol names.
5796 * Changes in completion.
5798 Commands such as `shell', `run' and `set args', which pass arguments
5799 to inferior programs, now complete on file names, similar to what
5800 users expect at the shell prompt.
5802 Commands which accept locations, such as `disassemble', `print',
5803 `breakpoint', `until', etc. now complete on filenames as well as
5804 program symbols. Thus, if you type "break foob TAB", and the source
5805 files linked into the programs include `foobar.c', that file name will
5806 be one of the candidates for completion. However, file names are not
5807 considered for completion after you typed a colon that delimits a file
5808 name from a name of a function in that file, as in "break foo.c:bar".
5810 `set demangle-style' completes on available demangling styles.
5812 * New platform-independent commands:
5814 It is now possible to define a post-hook for a command as well as a
5815 hook that runs before the command. For more details, see the
5816 documentation of `hookpost' in the GDB manual.
5818 * Changes in GNU/Linux native debugging.
5820 Support for debugging multi-threaded programs has been completely
5821 revised for all platforms except m68k and sparc. You can now debug as
5822 many threads as your system allows you to have.
5824 Attach/detach is supported for multi-threaded programs.
5826 Support for SSE registers was added for x86. This doesn't work for
5827 multi-threaded programs though.
5829 * Changes in MIPS configurations.
5831 Multi-arch support is enabled for all MIPS configurations.
5833 GDB can now be built as native debugger on SGI Irix 6.x systems for
5834 debugging n32 executables. (Debugging 64-bit executables is not yet
5837 * Unified support for hardware watchpoints in all x86 configurations.
5839 Most (if not all) native x86 configurations support hardware-assisted
5840 breakpoints and watchpoints in a unified manner. This support
5841 implements debug register sharing between watchpoints, which allows to
5842 put a virtually infinite number of watchpoints on the same address,
5843 and also supports watching regions up to 16 bytes with several debug
5846 The new maintenance command `maintenance show-debug-regs' toggles
5847 debugging print-outs in functions that insert, remove, and test
5848 watchpoints and hardware breakpoints.
5850 * Changes in the DJGPP native configuration.
5852 New command ``info dos sysinfo'' displays assorted information about
5853 the CPU, OS, memory, and DPMI server.
5855 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5856 display information about segment descriptors stored in GDT, LDT, and
5859 New commands ``info dos pde'' and ``info dos pte'' display entries
5860 from Page Directory and Page Tables (for now works with CWSDPMI only).
5861 New command ``info dos address-pte'' displays the Page Table entry for
5862 a given linear address.
5864 GDB can now pass command lines longer than 126 characters to the
5865 program being debugged (requires an update to the libdbg.a library
5866 which is part of the DJGPP development kit).
5868 DWARF2 debug info is now supported.
5870 It is now possible to `step' and `next' through calls to `longjmp'.
5872 * Changes in documentation.
5874 All GDB documentation was converted to GFDL, the GNU Free
5875 Documentation License.
5877 Tracepoints-related commands are now fully documented in the GDB
5880 TUI, the Text-mode User Interface, is now documented in the manual.
5882 Tracepoints-related commands are now fully documented in the GDB
5885 The "GDB Internals" manual now has an index. It also includes
5886 documentation of `ui_out' functions, GDB coding standards, x86
5887 hardware watchpoints, and memory region attributes.
5889 * GDB's version number moved to ``version.in''
5891 The Makefile variable VERSION has been replaced by the file
5892 ``version.in''. People creating GDB distributions should update the
5893 contents of this file.
5897 GUD support is now a standard part of the EMACS distribution.
5899 *** Changes in GDB 5.0:
5901 * Improved support for debugging FP programs on x86 targets
5903 Unified and much-improved support for debugging floating-point
5904 programs on all x86 targets. In particular, ``info float'' now
5905 displays the FP registers in the same format on all x86 targets, with
5906 greater level of detail.
5908 * Improvements and bugfixes in hardware-assisted watchpoints
5910 It is now possible to watch array elements, struct members, and
5911 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5912 on x86 targets no longer erroneously trigger when the address is
5915 * Improvements in the native DJGPP version of GDB
5917 The distribution now includes all the scripts and auxiliary files
5918 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5919 machines ``out of the box''.
5921 The DJGPP version can now debug programs that use signals. It is
5922 possible to catch signals that happened in the debuggee, deliver
5923 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5924 would kill the program being debugged.) Programs that hook hardware
5925 interrupts (keyboard, timer, etc.) can also be debugged.
5927 It is now possible to debug DJGPP programs that redirect their
5928 standard handles or switch them to raw (as opposed to cooked) mode, or
5929 even close them. The command ``run < foo > bar'' works as expected,
5930 and ``info terminal'' reports useful information about the debuggee's
5931 terminal, including raw/cooked mode, redirection, etc.
5933 The DJGPP version now uses termios functions for console I/O, which
5934 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5937 DOS-style file names with drive letters are now fully supported by
5940 It is now possible to debug DJGPP programs that switch their working
5941 directory. It is also possible to rerun the debuggee any number of
5942 times without restarting GDB; thus, you can use the same setup,
5943 breakpoints, etc. for many debugging sessions.
5945 * New native configurations
5947 ARM GNU/Linux arm*-*-linux*
5948 PowerPC GNU/Linux powerpc-*-linux*
5952 Motorola MCore mcore-*-*
5953 x86 VxWorks i[3456]86-*-vxworks*
5954 PowerPC VxWorks powerpc-*-vxworks*
5955 TI TMS320C80 tic80-*-*
5957 * OBSOLETE configurations
5959 Altos 3068 m68*-altos-*
5960 Convex c1-*-*, c2-*-*
5962 ARM RISCix arm-*-* (as host)
5965 Configurations that have been declared obsolete will be commented out,
5966 but the code will be left in place. If there is no activity to revive
5967 these configurations before the next release of GDB, the sources will
5968 be permanently REMOVED.
5970 * Gould support removed
5972 Support for the Gould PowerNode and NP1 has been removed.
5974 * New features for SVR4
5976 On SVR4 native platforms (such as Solaris), if you attach to a process
5977 without first loading a symbol file, GDB will now attempt to locate and
5978 load symbols from the running process's executable file.
5980 * Many C++ enhancements
5982 C++ support has been greatly improved. Overload resolution now works properly
5983 in almost all cases. RTTI support is on the way.
5985 * Remote targets can connect to a sub-program
5987 A popen(3) style serial-device has been added. This device starts a
5988 sub-process (such as a stand-alone simulator) and then communicates
5989 with that. The sub-program to run is specified using the syntax
5990 ``|<program> <args>'' vis:
5992 (gdb) set remotedebug 1
5993 (gdb) target extended-remote |mn10300-elf-sim program-args
5995 * MIPS 64 remote protocol
5997 A long standing bug in the mips64 remote protocol where by GDB
5998 expected certain 32 bit registers (ex SR) to be transfered as 32
5999 instead of 64 bits has been fixed.
6001 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6002 added to provide backward compatibility with older versions of GDB.
6004 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6006 The command ``set remotebinarydownload'' command has been replaced by
6007 ``set remote X-packet''. Other commands in ``set remote'' family
6008 include ``set remote P-packet''.
6010 * Breakpoint commands accept ranges.
6012 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6013 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6014 ``tracepoint passcount'' also accepts a range of tracepoints.
6016 * ``apropos'' command added.
6018 The ``apropos'' command searches through command names and
6019 documentation strings, printing out matches, making it much easier to
6020 try to find a command that does what you are looking for.
6024 A new machine oriented interface (MI) has been added to GDB. This
6025 interface is designed for debug environments running GDB as a separate
6026 process. This is part of the long term libGDB project. See the
6027 "GDB/MI" chapter of the GDB manual for further information. It can be
6028 enabled by configuring with:
6030 .../configure --enable-gdbmi
6032 *** Changes in GDB-4.18:
6034 * New native configurations
6036 HP-UX 10.20 hppa*-*-hpux10.20
6037 HP-UX 11.x hppa*-*-hpux11.0*
6038 M68K GNU/Linux m68*-*-linux*
6042 Fujitsu FR30 fr30-*-elf*
6043 Intel StrongARM strongarm-*-*
6044 Mitsubishi D30V d30v-*-*
6046 * OBSOLETE configurations
6048 Gould PowerNode, NP1 np1-*-*, pn-*-*
6050 Configurations that have been declared obsolete will be commented out,
6051 but the code will be left in place. If there is no activity to revive
6052 these configurations before the next release of GDB, the sources will
6053 be permanently REMOVED.
6057 As a compatibility experiment, GDB's source files buildsym.h and
6058 buildsym.c have been converted to pure standard C, no longer
6059 containing any K&R compatibility code. We believe that all systems in
6060 use today either come with a standard C compiler, or have a GCC port
6061 available. If this is not true, please report the affected
6062 configuration to bug-gdb@gnu.org immediately. See the README file for
6063 information about getting a standard C compiler if you don't have one
6068 GDB now uses readline 2.2.
6070 * set extension-language
6072 You can now control the mapping between filename extensions and source
6073 languages by using the `set extension-language' command. For instance,
6074 you can ask GDB to treat .c files as C++ by saying
6075 set extension-language .c c++
6076 The command `info extensions' lists all of the recognized extensions
6077 and their associated languages.
6079 * Setting processor type for PowerPC and RS/6000
6081 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6082 you can use the `set processor' command to specify what variant of the
6083 PowerPC family you are debugging. The command
6087 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6088 following PowerPC and RS6000 variants:
6090 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6091 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6093 403GC IBM PowerPC 403GC
6094 505 Motorola PowerPC 505
6095 860 Motorola PowerPC 860 or 850
6096 601 Motorola PowerPC 601
6097 602 Motorola PowerPC 602
6098 603 Motorola/IBM PowerPC 603 or 603e
6099 604 Motorola PowerPC 604 or 604e
6100 750 Motorola/IBM PowerPC 750 or 750
6102 At the moment, this command just tells GDB what to name the
6103 special-purpose processor registers. Since almost all the affected
6104 registers are inaccessible to user-level programs, this command is
6105 only useful for remote debugging in its present form.
6109 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6110 more extensive support for HP-UX. Added features include shared
6111 library support, kernel threads and hardware watchpoints for 11.00,
6112 support for HP's ANSI C and C++ compilers, and a compatibility mode
6113 for xdb and dbx commands.
6117 HP's donation includes the new concept of catchpoints, which is a
6118 generalization of the old catch command. On HP-UX, it is now possible
6119 to catch exec, fork, and vfork, as well as library loading.
6121 This means that the existing catch command has changed; its first
6122 argument now specifies the type of catch to be set up. See the
6123 output of "help catch" for a list of catchpoint types.
6125 * Debugging across forks
6127 On HP-UX, you can choose which process to debug when a fork() happens
6132 HP has donated a curses-based terminal user interface (TUI). To get
6133 it, build with --enable-tui. Although this can be enabled for any
6134 configuration, at present it only works for native HP debugging.
6136 * GDB remote protocol additions
6138 A new protocol packet 'X' that writes binary data is now available.
6139 Default behavior is to try 'X', then drop back to 'M' if the stub
6140 fails to respond. The settable variable `remotebinarydownload'
6141 allows explicit control over the use of 'X'.
6143 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6144 full 64-bit address. The command
6146 set remoteaddresssize 32
6148 can be used to revert to the old behaviour. For existing remote stubs
6149 the change should not be noticed, as the additional address information
6152 In order to assist in debugging stubs, you may use the maintenance
6153 command `packet' to send any text string to the stub. For instance,
6155 maint packet heythere
6157 sends the packet "$heythere#<checksum>". Note that it is very easy to
6158 disrupt a debugging session by sending the wrong packet at the wrong
6161 The compare-sections command allows you to compare section data on the
6162 target to what is in the executable file without uploading or
6163 downloading, by comparing CRC checksums.
6165 * Tracing can collect general expressions
6167 You may now collect general expressions at tracepoints. This requires
6168 further additions to the target-side stub; see tracepoint.c and
6169 doc/agentexpr.texi for further details.
6171 * mask-address variable for Mips
6173 For Mips targets, you may control the zeroing of the upper 32 bits of
6174 a 64-bit address by entering `set mask-address on'. This is mainly
6175 of interest to users of embedded R4xxx and R5xxx processors.
6177 * Higher serial baud rates
6179 GDB's serial code now allows you to specify baud rates 57600, 115200,
6180 230400, and 460800 baud. (Note that your host system may not be able
6181 to achieve all of these rates.)
6185 The i960 configuration now includes an initial implementation of a
6186 builtin simulator, contributed by Jim Wilson.
6189 *** Changes in GDB-4.17:
6191 * New native configurations
6193 Alpha GNU/Linux alpha*-*-linux*
6194 Unixware 2.x i[3456]86-unixware2*
6195 Irix 6.x mips*-sgi-irix6*
6196 PowerPC GNU/Linux powerpc-*-linux*
6197 PowerPC Solaris powerpcle-*-solaris*
6198 Sparc GNU/Linux sparc-*-linux*
6199 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6203 Argonaut Risc Chip (ARC) arc-*-*
6204 Hitachi H8/300S h8300*-*-*
6205 Matsushita MN10200 w/simulator mn10200-*-*
6206 Matsushita MN10300 w/simulator mn10300-*-*
6207 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6208 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6209 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6210 Mitsubishi D10V w/simulator d10v-*-*
6211 Mitsubishi M32R/D w/simulator m32r-*-elf*
6212 Tsqware Sparclet sparclet-*-*
6213 NEC V850 w/simulator v850-*-*
6215 * New debugging protocols
6217 ARM with RDI protocol arm*-*-*
6218 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6219 DDB and LSI variants of PMON protocol mips*-*-*
6220 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6221 PowerPC with SDS protocol powerpc{,le}-*-eabi
6222 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6226 All configurations can now understand and use the DWARF 2 debugging
6227 format. The choice is automatic, if the symbol file contains DWARF 2
6232 GDB now includes basic Java language support. This support is
6233 only useful with Java compilers that produce native machine code.
6235 * solib-absolute-prefix and solib-search-path
6237 For SunOS and SVR4 shared libraries, you may now set the prefix for
6238 loading absolute shared library symbol files, and the search path for
6239 locating non-absolute shared library symbol files.
6241 * Live range splitting
6243 GDB can now effectively debug code for which GCC has performed live
6244 range splitting as part of its optimization. See gdb/doc/LRS for
6245 more details on the expected format of the stabs information.
6249 GDB's support for the GNU Hurd, including thread debugging, has been
6250 updated to work with current versions of the Hurd.
6254 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6255 instruction set. ARM GDB automatically detects when Thumb
6256 instructions are in use, and adjusts disassembly and backtracing
6261 GDB's MIPS target configurations now handle the MIP16 16-bit
6266 GDB now includes support for overlays; if an executable has been
6267 linked such that multiple sections are based at the same address, GDB
6268 will decide which section to use for symbolic info. You can choose to
6269 control the decision manually, using overlay commands, or implement
6270 additional target-side support and use "overlay load-target" to bring
6271 in the overlay mapping. Do "help overlay" for more detail.
6275 The command "info symbol <address>" displays information about
6276 the symbol at the specified address.
6280 The standard remote protocol now includes an extension that allows
6281 asynchronous collection and display of trace data. This requires
6282 extensive support in the target-side debugging stub. Tracing mode
6283 includes a new interaction mode in GDB and new commands: see the
6284 file tracepoint.c for more details.
6288 Configurations for embedded MIPS now include a simulator contributed
6289 by Cygnus Solutions. The simulator supports the instruction sets
6290 of most MIPS variants.
6294 Sparc configurations may now include the ERC32 simulator contributed
6295 by the European Space Agency. The simulator is not built into
6296 Sparc targets by default; configure with --enable-sim to include it.
6300 For target configurations that may include multiple variants of a
6301 basic architecture (such as MIPS and SH), you may now set the
6302 architecture explicitly. "set arch" sets, "info arch" lists
6303 the possible architectures.
6305 *** Changes in GDB-4.16:
6307 * New native configurations
6309 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6310 M68K NetBSD m68k-*-netbsd*
6311 PowerPC AIX 4.x powerpc-*-aix*
6312 PowerPC MacOS powerpc-*-macos*
6313 PowerPC Windows NT powerpcle-*-cygwin32
6314 RS/6000 AIX 4.x rs6000-*-aix4*
6318 ARM with RDP protocol arm-*-*
6319 I960 with MON960 i960-*-coff
6320 MIPS VxWorks mips*-*-vxworks*
6321 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6322 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6324 Matra Sparclet sparclet-*-*
6328 The powerpc-eabi configuration now includes the PSIM simulator,
6329 contributed by Andrew Cagney, with assistance from Mike Meissner.
6330 PSIM is a very elaborate model of the PowerPC, including not only
6331 basic instruction set execution, but also details of execution unit
6332 performance and I/O hardware. See sim/ppc/README for more details.
6336 GDB now works with Solaris 2.5.
6338 * Windows 95/NT native
6340 GDB will now work as a native debugger on Windows 95 and Windows NT.
6341 To build it from source, you must use the "gnu-win32" environment,
6342 which uses a DLL to emulate enough of Unix to run the GNU tools.
6343 Further information, binaries, and sources are available at
6344 ftp.cygnus.com, under pub/gnu-win32.
6346 * dont-repeat command
6348 If a user-defined command includes the command `dont-repeat', then the
6349 command will not be repeated if the user just types return. This is
6350 useful if the command is time-consuming to run, so that accidental
6351 extra keystrokes don't run the same command many times.
6353 * Send break instead of ^C
6355 The standard remote protocol now includes an option to send a break
6356 rather than a ^C to the target in order to interrupt it. By default,
6357 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6359 * Remote protocol timeout
6361 The standard remote protocol includes a new variable `remotetimeout'
6362 that allows you to set the number of seconds before GDB gives up trying
6363 to read from the target. The default value is 2.
6365 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6367 By default GDB will automatically keep track of objects as they are
6368 loaded and unloaded by the dynamic linker. By using the command `set
6369 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6370 when shared library events occur, thus allowing you to set breakpoints
6371 in shared libraries which are explicitly loaded by the inferior.
6373 Note this feature does not work on hpux8. On hpux9 you must link
6374 /usr/lib/end.o into your program. This feature should work
6375 automatically on hpux10.
6377 * Irix 5.x hardware watchpoint support
6379 Irix 5 configurations now support the use of hardware watchpoints.
6381 * Mips protocol "SYN garbage limit"
6383 When debugging a Mips target using the `target mips' protocol, you
6384 may set the number of characters that GDB will ignore by setting
6385 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6386 every character. The default value is 1050.
6388 * Recording and replaying remote debug sessions
6390 If you set `remotelogfile' to the name of a file, gdb will write to it
6391 a recording of a remote debug session. This recording may then be
6392 replayed back to gdb using "gdbreplay". See gdbserver/README for
6393 details. This is useful when you have a problem with GDB while doing
6394 remote debugging; you can make a recording of the session and send it
6395 to someone else, who can then recreate the problem.
6397 * Speedups for remote debugging
6399 GDB includes speedups for downloading and stepping MIPS systems using
6400 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6401 and more efficient S-record downloading.
6403 * Memory use reductions and statistics collection
6405 GDB now uses less memory and reports statistics about memory usage.
6406 Try the `maint print statistics' command, for example.
6408 *** Changes in GDB-4.15:
6410 * Psymtabs for XCOFF
6412 The symbol reader for AIX GDB now uses partial symbol tables. This
6413 can greatly improve startup time, especially for large executables.
6415 * Remote targets use caching
6417 Remote targets now use a data cache to speed up communication with the
6418 remote side. The data cache could lead to incorrect results because
6419 it doesn't know about volatile variables, thus making it impossible to
6420 debug targets which use memory mapped I/O devices. `set remotecache
6421 off' turns the the data cache off.
6423 * Remote targets may have threads
6425 The standard remote protocol now includes support for multiple threads
6426 in the target system, using new protocol commands 'H' and 'T'. See
6427 gdb/remote.c for details.
6431 If GDB is configured with `--enable-netrom', then it will include
6432 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6433 acts as though it is a bank of ROM on the target board, but you can
6434 write into it over the network. GDB's support consists only of
6435 support for fast loading into the emulated ROM; to debug, you must use
6436 another protocol, such as standard remote protocol. The usual
6437 sequence is something like
6439 target nrom <netrom-hostname>
6441 target remote <netrom-hostname>:1235
6445 GDB now includes support for the Apple Macintosh, as a host only. It
6446 may be run as either an MPW tool or as a standalone application, and
6447 it can debug through the serial port. All the usual GDB commands are
6448 available, but to the target command, you must supply "serial" as the
6449 device type instead of "/dev/ttyXX". See mpw-README in the main
6450 directory for more information on how to build. The MPW configuration
6451 scripts */mpw-config.in support only a few targets, and only the
6452 mips-idt-ecoff target has been tested.
6456 GDB configuration now uses autoconf. This is not user-visible,
6457 but does simplify configuration and building.
6461 GDB now supports hpux10.
6463 *** Changes in GDB-4.14:
6465 * New native configurations
6467 x86 FreeBSD i[345]86-*-freebsd
6468 x86 NetBSD i[345]86-*-netbsd
6469 NS32k NetBSD ns32k-*-netbsd
6470 Sparc NetBSD sparc-*-netbsd
6474 A29K VxWorks a29k-*-vxworks
6475 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6476 CPU32 EST-300 emulator m68*-*-est*
6477 PowerPC ELF powerpc-*-elf
6480 * Alpha OSF/1 support for procfs
6482 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6483 possible to attach to running processes. As the mounting of the /proc
6484 filesystem is optional on the Alpha, GDB automatically determines
6485 the availability of /proc during startup. This can lead to problems
6486 if /proc is unmounted after GDB has been started.
6488 * Arguments to user-defined commands
6490 User commands may accept up to 10 arguments separated by whitespace.
6491 Arguments are accessed within the user command via $arg0..$arg9. A
6494 print $arg0 + $arg1 + $arg2
6496 To execute the command use:
6499 Defines the command "adder" which prints the sum of its three arguments.
6500 Note the arguments are text substitutions, so they may reference variables,
6501 use complex expressions, or even perform inferior function calls.
6503 * New `if' and `while' commands
6505 This makes it possible to write more sophisticated user-defined
6506 commands. Both commands take a single argument, which is the
6507 expression to evaluate, and must be followed by the commands to
6508 execute, one per line, if the expression is nonzero, the list being
6509 terminated by the word `end'. The `if' command list may include an
6510 `else' word, which causes the following commands to be executed only
6511 if the expression is zero.
6513 * Fortran source language mode
6515 GDB now includes partial support for Fortran 77. It will recognize
6516 Fortran programs and can evaluate a subset of Fortran expressions, but
6517 variables and functions may not be handled correctly. GDB will work
6518 with G77, but does not yet know much about symbols emitted by other
6521 * Better HPUX support
6523 Most debugging facilities now work on dynamic executables for HPPAs
6524 running hpux9 or later. You can attach to running dynamically linked
6525 processes, but by default the dynamic libraries will be read-only, so
6526 for instance you won't be able to put breakpoints in them. To change
6527 that behavior do the following before running the program:
6533 This will cause the libraries to be mapped private and read-write.
6534 To revert to the normal behavior, do this:
6540 You cannot set breakpoints or examine data in the library until after
6541 the library is loaded if the function/data symbols do not have
6544 GDB can now also read debug symbols produced by the HP C compiler on
6545 HPPAs (sorry, no C++, Fortran or 68k support).
6547 * Target byte order now dynamically selectable
6549 You can choose which byte order to use with a target system, via the
6550 commands "set endian big" and "set endian little", and you can see the
6551 current setting by using "show endian". You can also give the command
6552 "set endian auto", in which case GDB will use the byte order
6553 associated with the executable. Currently, only embedded MIPS
6554 configurations support dynamic selection of target byte order.
6556 * New DOS host serial code
6558 This version uses DPMI interrupts to handle buffered I/O, so you
6559 no longer need to run asynctsr when debugging boards connected to
6562 *** Changes in GDB-4.13:
6564 * New "complete" command
6566 This lists all the possible completions for the rest of the line, if it
6567 were to be given as a command itself. This is intended for use by emacs.
6569 * Trailing space optional in prompt
6571 "set prompt" no longer adds a space for you after the prompt you set. This
6572 allows you to set a prompt which ends in a space or one that does not.
6574 * Breakpoint hit counts
6576 "info break" now displays a count of the number of times the breakpoint
6577 has been hit. This is especially useful in conjunction with "ignore"; you
6578 can ignore a large number of breakpoint hits, look at the breakpoint info
6579 to see how many times the breakpoint was hit, then run again, ignoring one
6580 less than that number, and this will get you quickly to the last hit of
6583 * Ability to stop printing at NULL character
6585 "set print null-stop" will cause GDB to stop printing the characters of
6586 an array when the first NULL is encountered. This is useful when large
6587 arrays actually contain only short strings.
6589 * Shared library breakpoints
6591 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6592 breakpoints in shared libraries before the executable is run.
6594 * Hardware watchpoints
6596 There is a new hardware breakpoint for the watch command for sparclite
6597 targets. See gdb/sparclite/hw_breakpoint.note.
6599 Hardware watchpoints are also now supported under GNU/Linux.
6603 Annotations have been added. These are for use with graphical interfaces,
6604 and are still experimental. Currently only gdba.el uses these.
6606 * Improved Irix 5 support
6608 GDB now works properly with Irix 5.2.
6610 * Improved HPPA support
6612 GDB now works properly with the latest GCC and GAS.
6614 * New native configurations
6616 Sequent PTX4 i[34]86-sequent-ptx4
6617 HPPA running OSF/1 hppa*-*-osf*
6618 Atari TT running SVR4 m68*-*-sysv4*
6619 RS/6000 LynxOS rs6000-*-lynxos*
6623 OS/9000 i[34]86-*-os9k
6624 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6627 * Hitachi SH7000 and E7000-PC ICE support
6629 There is now support for communicating with the Hitachi E7000-PC ICE.
6630 This is available automatically when GDB is configured for the SH.
6634 As usual, a variety of small fixes and improvements, both generic
6635 and configuration-specific. See the ChangeLog for more detail.
6637 *** Changes in GDB-4.12:
6639 * Irix 5 is now supported
6643 GDB-4.12 on the HPPA has a number of changes which make it unable
6644 to debug the output from the currently released versions of GCC and
6645 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6646 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6647 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6650 *** Changes in GDB-4.11:
6652 * User visible changes:
6656 The "set remotedebug" option is now consistent between the mips remote
6657 target, remote targets using the gdb-specific protocol, UDI (AMD's
6658 debug protocol for the 29k) and the 88k bug monitor. It is now an
6659 integer specifying a debug level (normally 0 or 1, but 2 means more
6660 debugging info for the mips target).
6662 * DEC Alpha native support
6664 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6665 debug info, but GDB works fairly well with the DEC compiler and should
6666 work with a future GCC release. See the README file for a few
6667 Alpha-specific notes.
6669 * Preliminary thread implementation
6671 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6673 * LynxOS native and target support for 386
6675 This release has been hosted on LynxOS 2.2, and also can be configured
6676 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6679 * Improvements in C++ mangling/demangling.
6681 This release has much better g++ debugging, specifically in name
6682 mangling/demangling, virtual function calls, print virtual table,
6683 call methods, ...etc.
6685 *** Changes in GDB-4.10:
6687 * User visible changes:
6689 Remote debugging using the GDB-specific (`target remote') protocol now
6690 supports the `load' command. This is only useful if you have some
6691 other way of getting the stub to the target system, and you can put it
6692 somewhere in memory where it won't get clobbered by the download.
6694 Filename completion now works.
6696 When run under emacs mode, the "info line" command now causes the
6697 arrow to point to the line specified. Also, "info line" prints
6698 addresses in symbolic form (as well as hex).
6700 All vxworks based targets now support a user settable option, called
6701 vxworks-timeout. This option represents the number of seconds gdb
6702 should wait for responses to rpc's. You might want to use this if
6703 your vxworks target is, perhaps, a slow software simulator or happens
6704 to be on the far side of a thin network line.
6708 This release contains support for using a DEC alpha as a GDB host for
6709 cross debugging. Native alpha debugging is not supported yet.
6712 *** Changes in GDB-4.9:
6716 This is the first GDB release which is accompanied by a matching testsuite.
6717 The testsuite requires installation of dejagnu, which should be available
6718 via ftp from most sites that carry GNU software.
6722 'Cfront' style demangling has had its name changed to 'ARM' style, to
6723 emphasize that it was written from the specifications in the C++ Annotated
6724 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6725 disclaimers, it still generated too much confusion with users attempting to
6726 use gdb with AT&T cfront.
6730 GDB now uses a standard remote interface to a simulator library.
6731 So far, the library contains simulators for the Zilog Z8001/2, the
6732 Hitachi H8/300, H8/500 and Super-H.
6734 * New targets supported
6736 H8/300 simulator h8300-hitachi-hms or h8300hms
6737 H8/500 simulator h8500-hitachi-hms or h8500hms
6738 SH simulator sh-hitachi-hms or sh
6739 Z8000 simulator z8k-zilog-none or z8ksim
6740 IDT MIPS board over serial line mips-idt-ecoff
6742 Cross-debugging to GO32 targets is supported. It requires a custom
6743 version of the i386-stub.c module which is integrated with the
6744 GO32 memory extender.
6746 * New remote protocols
6748 MIPS remote debugging protocol.
6750 * New source languages supported
6752 This version includes preliminary support for Chill, a Pascal like language
6753 used by telecommunications companies. Chill support is also being integrated
6754 into the GNU compiler, but we don't know when it will be publically available.
6757 *** Changes in GDB-4.8:
6759 * HP Precision Architecture supported
6761 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6762 version of this support was available as a set of patches from the
6763 University of Utah. GDB does not support debugging of programs
6764 compiled with the HP compiler, because HP will not document their file
6765 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6766 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6768 Many problems in the preliminary version have been fixed.
6770 * Faster and better demangling
6772 We have improved template demangling and fixed numerous bugs in the GNU style
6773 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6774 character types (wchar_t) are now supported. Demangling of each symbol is now
6775 only done once, and is cached when the symbol table for a file is read in.
6776 This results in a small increase in memory usage for C programs, a moderate
6777 increase in memory usage for C++ programs, and a fantastic speedup in
6780 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6781 from the specifications in the Annotated Reference Manual, which AT&T's
6782 compiler does not actually implement.
6784 * G++ multiple inheritance compiler problem
6786 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6787 inheritance lattices was reworked to properly discover ambiguities. We
6788 recently found an example which causes this new algorithm to fail in a
6789 very subtle way, producing bad debug information for those classes.
6790 The file 'gcc.patch' (in this directory) can be applied to gcc to
6791 circumvent the problem. A future GCC release will contain a complete
6794 The previous G++ debug info problem (mentioned below for the gdb-4.7
6795 release) is fixed in gcc version 2.3.2.
6797 * Improved configure script
6799 The `configure' script will now attempt to guess your system type if
6800 you don't supply a host system type. The old scheme of supplying a
6801 host system triplet is preferable over using this. All the magic is
6802 done in the new `config.guess' script. Examine it for details.
6804 We have also brought our configure script much more in line with the FSF's
6805 version. It now supports the --with-xxx options. In particular,
6806 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6807 The resulting GDB will not be able to read arbitrary object file formats --
6808 only the format ``expected'' to be used on the configured target system.
6809 We hope to make this the default in a future release.
6811 * Documentation improvements
6813 There's new internal documentation on how to modify GDB, and how to
6814 produce clean changes to the code. We implore people to read it
6815 before submitting changes.
6817 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6818 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6819 `info' files are also provided. To build `info' files from scratch,
6820 you will need the latest `makeinfo' release, which will be available in
6821 a future texinfo-X.Y release.
6823 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6824 We're not sure exactly which versions have this problem, but it has
6825 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6826 or better. If that isn't possible, there is a patch in
6827 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6828 around this problem.
6832 GDB now supports array constants that can be used in expressions typed in by
6833 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6834 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6837 The new directory `gdb/sparclite' contains a program that demonstrates
6838 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6840 * New native hosts supported
6842 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6843 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6845 * New targets supported
6847 AMD 29k family via UDI a29k-amd-udi or udi29k
6849 * New file formats supported
6851 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6852 HPUX core files, and SCO 3.2v2 core files.
6856 Attaching to processes now works again; thanks for the many bug reports.
6858 We have also stomped on a bunch of core dumps caused by
6859 printf_filtered("%s") problems.
6861 We eliminated a copyright problem on the rpc and ptrace header files
6862 for VxWorks, which was discovered at the last minute during the 4.7
6863 release. You should now be able to build a VxWorks GDB.
6865 You can now interrupt gdb while an attached process is running. This
6866 will cause the attached process to stop, and give control back to GDB.
6868 We fixed problems caused by using too many file descriptors
6869 for reading symbols from object files and libraries. This was
6870 especially a problem for programs that used many (~100) shared
6873 The `step' command now only enters a subroutine if there is line number
6874 information for the subroutine. Otherwise it acts like the `next'
6875 command. Previously, `step' would enter subroutines if there was
6876 any debugging information about the routine. This avoids problems
6877 when using `cc -g1' on MIPS machines.
6879 * Internal improvements
6881 GDB's internal interfaces have been improved to make it easier to support
6882 debugging of multiple languages in the future.
6884 GDB now uses a common structure for symbol information internally.
6885 Minimal symbols (derived from linkage symbols in object files), partial
6886 symbols (from a quick scan of debug information), and full symbols
6887 contain a common subset of information, making it easier to write
6888 shared code that handles any of them.
6890 * New command line options
6892 We now accept --silent as an alias for --quiet.
6896 The memory-mapped-malloc library is now licensed under the GNU Library
6897 General Public License.
6899 *** Changes in GDB-4.7:
6901 * Host/native/target split
6903 GDB has had some major internal surgery to untangle the support for
6904 hosts and remote targets. Now, when you configure GDB for a remote
6905 target, it will no longer load in all of the support for debugging
6906 local programs on the host. When fully completed and tested, this will
6907 ensure that arbitrary host/target combinations are possible.
6909 The primary conceptual shift is to separate the non-portable code in
6910 GDB into three categories. Host specific code is required any time GDB
6911 is compiled on that host, regardless of the target. Target specific
6912 code relates to the peculiarities of the target, but can be compiled on
6913 any host. Native specific code is everything else: it can only be
6914 built when the host and target are the same system. Child process
6915 handling and core file support are two common `native' examples.
6917 GDB's use of /proc for controlling Unix child processes is now cleaner.
6918 It has been split out into a single module under the `target_ops' vector,
6919 plus two native-dependent functions for each system that uses /proc.
6921 * New hosts supported
6923 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6924 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6925 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6927 * New targets supported
6929 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6930 68030 and CPU32 m68030-*-*, m68332-*-*
6932 * New native hosts supported
6934 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6935 (386bsd is not well tested yet)
6936 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6938 * New file formats supported
6940 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6941 supports reading of `a.out.adobe' object files, which are an a.out
6942 format extended with minimal information about multiple sections.
6946 `show copying' is the same as the old `info copying'.
6947 `show warranty' is the same as `info warrantee'.
6948 These were renamed for consistency. The old commands continue to work.
6950 `info handle' is a new alias for `info signals'.
6952 You can now define pre-command hooks, which attach arbitrary command
6953 scripts to any command. The commands in the hook will be executed
6954 prior to the user's command. You can also create a hook which will be
6955 executed whenever the program stops. See gdb.texinfo.
6959 We now deal with Cfront style name mangling, and can even extract type
6960 info from mangled symbols. GDB can automatically figure out which
6961 symbol mangling style your C++ compiler uses.
6963 Calling of methods and virtual functions has been improved as well.
6967 The crash that occured when debugging Sun Ansi-C compiled binaries is
6968 fixed. This was due to mishandling of the extra N_SO stabs output
6971 We also finally got Ultrix 4.2 running in house, and fixed core file
6972 support, with help from a dozen people on the net.
6974 John M. Farrell discovered that the reason that single-stepping was so
6975 slow on all of the Mips based platforms (primarily SGI and DEC) was
6976 that we were trying to demangle and lookup a symbol used for internal
6977 purposes on every instruction that was being stepped through. Changing
6978 the name of that symbol so that it couldn't be mistaken for a C++
6979 mangled symbol sped things up a great deal.
6981 Rich Pixley sped up symbol lookups in general by getting much smarter
6982 about when C++ symbol mangling is necessary. This should make symbol
6983 completion (TAB on the command line) much faster. It's not as fast as
6984 we'd like, but it's significantly faster than gdb-4.6.
6988 A new user controllable variable 'call_scratch_address' can
6989 specify the location of a scratch area to be used when GDB
6990 calls a function in the target. This is necessary because the
6991 usual method of putting the scratch area on the stack does not work
6992 in systems that have separate instruction and data spaces.
6994 We integrated changes to support the 29k UDI (Universal Debugger
6995 Interface), but discovered at the last minute that we didn't have all
6996 of the appropriate copyright paperwork. We are working with AMD to
6997 resolve this, and hope to have it available soon.
7001 We have sped up the remote serial line protocol, especially for targets
7002 with lots of registers. It now supports a new `expedited status' ('T')
7003 message which can be used in place of the existing 'S' status message.
7004 This allows the remote stub to send only the registers that GDB
7005 needs to make a quick decision about single-stepping or conditional
7006 breakpoints, eliminating the need to fetch the entire register set for
7007 each instruction being stepped through.
7009 The GDB remote serial protocol now implements a write-through cache for
7010 registers, only re-reading the registers if the target has run.
7012 There is also a new remote serial stub for SPARC processors. You can
7013 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7014 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7015 processor with a serial port.
7019 Configure.in files have become much easier to read and modify. A new
7020 `table driven' format makes it more obvious what configurations are
7021 supported, and what files each one uses.
7025 There is a new opcodes library which will eventually contain all of the
7026 disassembly routines and opcode tables. At present, it only contains
7027 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7028 disassembler (binutils/objdump) to share these routines.
7030 The libiberty library is now copylefted under the GNU Library General
7031 Public License. This allows more liberal use, and was done so libg++
7032 can use it. This makes no difference to GDB, since the Library License
7033 grants all the rights from the General Public License.
7037 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7038 reference to the stabs symbol info used by the debugger. It is (as far
7039 as we know) the only published document on this fascinating topic. We
7040 encourage you to read it, compare it to the stabs information on your
7041 system, and send improvements on the document in general (to
7042 bug-gdb@prep.ai.mit.edu).
7044 And, of course, many bugs have been fixed.
7047 *** Changes in GDB-4.6:
7049 * Better support for C++ function names
7051 GDB now accepts as input the "demangled form" of C++ overloaded function
7052 names and member function names, and can do command completion on such names
7053 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7054 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7055 Make use of command completion, it is your friend.
7057 GDB also now accepts a variety of C++ mangled symbol formats. They are
7058 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7059 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7060 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7061 for the list of formats.
7063 * G++ symbol mangling problem
7065 Recent versions of gcc have a bug in how they emit debugging information for
7066 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7067 directory) can be applied to gcc to fix the problem. Alternatively, if you
7068 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7069 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7070 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7073 * New 'maintenance' command
7075 All of the commands related to hacking GDB internals have been moved out of
7076 the main command set, and now live behind the 'maintenance' command. This
7077 can also be abbreviated as 'mt'. The following changes were made:
7079 dump-me -> maintenance dump-me
7080 info all-breakpoints -> maintenance info breakpoints
7081 printmsyms -> maintenance print msyms
7082 printobjfiles -> maintenance print objfiles
7083 printpsyms -> maintenance print psymbols
7084 printsyms -> maintenance print symbols
7086 The following commands are new:
7088 maintenance demangle Call internal GDB demangler routine to
7089 demangle a C++ link name and prints the result.
7090 maintenance print type Print a type chain for a given symbol
7092 * Change to .gdbinit file processing
7094 We now read the $HOME/.gdbinit file before processing the argv arguments
7095 (e.g. reading symbol files or core files). This allows global parameters to
7096 be set, which will apply during the symbol reading. The ./.gdbinit is still
7097 read after argv processing.
7099 * New hosts supported
7101 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7103 GNU/Linux support i386-unknown-linux or linux
7105 We are also including code to support the HP/PA running BSD and HPUX. This
7106 is almost guaranteed not to work, as we didn't have time to test or build it
7107 for this release. We are including it so that the more adventurous (or
7108 masochistic) of you can play with it. We also had major problems with the
7109 fact that the compiler that we got from HP doesn't support the -g option.
7112 * New targets supported
7114 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7116 * More smarts about finding #include files
7118 GDB now remembers the compilation directory for all include files, and for
7119 all files from which C is generated (like yacc and lex sources). This
7120 greatly improves GDB's ability to find yacc/lex sources, and include files,
7121 especially if you are debugging your program from a directory different from
7122 the one that contains your sources.
7124 We also fixed a bug which caused difficulty with listing and setting
7125 breakpoints in include files which contain C code. (In the past, you had to
7126 try twice in order to list an include file that you hadn't looked at before.)
7128 * Interesting infernals change
7130 GDB now deals with arbitrary numbers of sections, where the symbols for each
7131 section must be relocated relative to that section's landing place in the
7132 target's address space. This work was needed to support ELF with embedded
7133 stabs used by Solaris-2.0.
7135 * Bug fixes (of course!)
7137 There have been loads of fixes for the following things:
7138 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7139 i960, stabs, DOS(GO32), procfs, etc...
7141 See the ChangeLog for details.
7143 *** Changes in GDB-4.5:
7145 * New machines supported (host and target)
7147 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7149 SGI Irix-4.x mips-sgi-irix4 or iris4
7151 * New malloc package
7153 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7154 Mmalloc is capable of handling mutiple heaps of memory. It is also
7155 capable of saving a heap to a file, and then mapping it back in later.
7156 This can be used to greatly speedup the startup of GDB by using a
7157 pre-parsed symbol table which lives in a mmalloc managed heap. For
7158 more details, please read mmalloc/mmalloc.texi.
7162 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7163 'help info proc' for details.
7165 * MIPS ecoff symbol table format
7167 The code that reads MIPS symbol table format is now supported on all hosts.
7168 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7171 * File name changes for MS-DOS
7173 Many files in the config directories have been renamed to make it easier to
7174 support GDB on MS-DOSe systems (which have very restrictive file name
7175 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7176 environment) is close to working but has some remaining problems. Note
7177 that debugging of DOS programs is not supported, due to limitations
7178 in the ``operating system'', but it can be used to host cross-debugging.
7180 * Cross byte order fixes
7182 Many fixes have been made to support cross debugging of Sparc and MIPS
7183 targets from hosts whose byte order differs.
7185 * New -mapped and -readnow options
7187 If memory-mapped files are available on your system through the 'mmap'
7188 system call, you can use the -mapped option on the `file' or
7189 `symbol-file' commands to cause GDB to write the symbols from your
7190 program into a reusable file. If the program you are debugging is
7191 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7192 Future GDB debugging sessions will notice the presence of this file,
7193 and will quickly map in symbol information from it, rather than reading
7194 the symbol table from the executable program. Using the '-mapped'
7195 option in a GDB `file' or `symbol-file' command has the same effect as
7196 starting GDB with the '-mapped' command-line option.
7198 You can cause GDB to read the entire symbol table immediately by using
7199 the '-readnow' option with any of the commands that load symbol table
7200 information (or on the GDB command line). This makes the command
7201 slower, but makes future operations faster.
7203 The -mapped and -readnow options are typically combined in order to
7204 build a `fred.syms' file that contains complete symbol information.
7205 A simple GDB invocation to do nothing but build a `.syms' file for future
7208 gdb -batch -nx -mapped -readnow programname
7210 The `.syms' file is specific to the host machine on which GDB is run.
7211 It holds an exact image of GDB's internal symbol table. It cannot be
7212 shared across multiple host platforms.
7214 * longjmp() handling
7216 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7217 siglongjmp() without losing control. This feature has not yet been ported to
7218 all systems. It currently works on many 386 platforms, all MIPS-based
7219 platforms (SGI, DECstation, etc), and Sun3/4.
7223 Preliminary work has been put in to support the new Solaris OS from Sun. At
7224 this time, it can control and debug processes, but it is not capable of
7229 As always, many many bug fixes. The major areas were with g++, and mipsread.
7230 People using the MIPS-based platforms should experience fewer mysterious
7231 crashes and trashed symbol tables.
7233 *** Changes in GDB-4.4:
7235 * New machines supported (host and target)
7237 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7239 BSD Reno on Vax vax-dec-bsd
7240 Ultrix on Vax vax-dec-ultrix
7242 * New machines supported (target)
7244 AMD 29000 embedded, using EBMON a29k-none-none
7248 GDB continues to improve its handling of C++. `References' work better.
7249 The demangler has also been improved, and now deals with symbols mangled as
7250 per the Annotated C++ Reference Guide.
7252 GDB also now handles `stabs' symbol information embedded in MIPS
7253 `ecoff' symbol tables. Since the ecoff format was not easily
7254 extensible to handle new languages such as C++, this appeared to be a
7255 good way to put C++ debugging info into MIPS binaries. This option
7256 will be supported in the GNU C compiler, version 2, when it is
7259 * New features for SVR4
7261 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7262 shared libraries. Debugging dynamically linked programs should present
7263 only minor differences from debugging statically linked programs.
7265 The `info proc' command will print out information about any process
7266 on an SVR4 system (including the one you are debugging). At the moment,
7267 it prints the address mappings of the process.
7269 If you bring up GDB on another SVR4 system, please send mail to
7270 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7272 * Better dynamic linking support in SunOS
7274 Reading symbols from shared libraries which contain debugging symbols
7275 now works properly. However, there remain issues such as automatic
7276 skipping of `transfer vector' code during function calls, which
7277 make it harder to debug code in a shared library, than to debug the
7278 same code linked statically.
7282 GDB is now using the latest `getopt' routines from the FSF. This
7283 version accepts the -- prefix for options with long names. GDB will
7284 continue to accept the old forms (-option and +option) as well.
7285 Various single letter abbreviations for options have been explicity
7286 added to the option table so that they won't get overshadowed in the
7287 future by other options that begin with the same letter.
7291 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7292 Many assorted bugs have been handled. Many more remain to be handled.
7293 See the various ChangeLog files (primarily in gdb and bfd) for details.
7296 *** Changes in GDB-4.3:
7298 * New machines supported (host and target)
7300 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7301 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7302 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7304 * Almost SCO Unix support
7306 We had hoped to support:
7307 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7308 (except for core file support), but we discovered very late in the release
7309 that it has problems with process groups that render gdb unusable. Sorry
7310 about that. I encourage people to fix it and post the fixes.
7312 * Preliminary ELF and DWARF support
7314 GDB can read ELF object files on System V Release 4, and can handle
7315 debugging records for C, in DWARF format, in ELF files. This support
7316 is preliminary. If you bring up GDB on another SVR4 system, please
7317 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7322 GDB now uses the latest `readline' library. One user-visible change
7323 is that two tabs will list possible command completions, which previously
7324 required typing M-? (meta-question mark, or ESC ?).
7328 The `stepi' bug that many of you noticed has been squashed.
7329 Many bugs in C++ have been handled. Many more remain to be handled.
7330 See the various ChangeLog files (primarily in gdb and bfd) for details.
7332 * State of the MIPS world (in case you wondered):
7334 GDB can understand the symbol tables emitted by the compilers
7335 supplied by most vendors of MIPS-based machines, including DEC. These
7336 symbol tables are in a format that essentially nobody else uses.
7338 Some versions of gcc come with an assembler post-processor called
7339 mips-tfile. This program is required if you want to do source-level
7340 debugging of gcc-compiled programs. I believe FSF does not ship
7341 mips-tfile with gcc version 1, but it will eventually come with gcc
7344 Debugging of g++ output remains a problem. g++ version 1.xx does not
7345 really support it at all. (If you're lucky, you should be able to get
7346 line numbers and stack traces to work, but no parameters or local
7347 variables.) With some work it should be possible to improve the
7350 When gcc version 2 is released, you will have somewhat better luck.
7351 However, even then you will get confusing results for inheritance and
7354 We will eventually provide full debugging of g++ output on
7355 DECstations. This will probably involve some kind of stabs-in-ecoff
7356 encapulation, but the details have not been worked out yet.
7359 *** Changes in GDB-4.2:
7361 * Improved configuration
7363 Only one copy of `configure' exists now, and it is not self-modifying.
7364 Porting BFD is simpler.
7368 The `step' and `next' commands now only stop at the first instruction
7369 of a source line. This prevents the multiple stops that used to occur
7370 in switch statements, for-loops, etc. `Step' continues to stop if a
7371 function that has debugging information is called within the line.
7375 Lots of small bugs fixed. More remain.
7377 * New host supported (not target)
7379 Intel 386 PC clone running Mach i386-none-mach
7382 *** Changes in GDB-4.1:
7384 * Multiple source language support
7386 GDB now has internal scaffolding to handle several source languages.
7387 It determines the type of each source file from its filename extension,
7388 and will switch expression parsing and number formatting to match the
7389 language of the function in the currently selected stack frame.
7390 You can also specifically set the language to be used, with
7391 `set language c' or `set language modula-2'.
7395 GDB now has preliminary support for the GNU Modula-2 compiler,
7396 currently under development at the State University of New York at
7397 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7398 continue through the fall of 1991 and into 1992.
7400 Other Modula-2 compilers are currently not supported, and attempting to
7401 debug programs compiled with them will likely result in an error as the
7402 symbol table is read. Feel free to work on it, though!
7404 There are hooks in GDB for strict type checking and range checking,
7405 in the `Modula-2 philosophy', but they do not currently work.
7409 GDB can now write to executable and core files (e.g. patch
7410 a variable's value). You must turn this switch on, specify
7411 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7412 by assigning a new value to a variable. Modifications take
7415 * Automatic SunOS shared library reading
7417 When you run your program, GDB automatically determines where its
7418 shared libraries (if any) have been loaded, and reads their symbols.
7419 The `share' command is no longer needed. This also works when
7420 examining core files.
7424 You can specify the number of lines that the `list' command shows.
7427 * New machines supported (host and target)
7429 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7430 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7431 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7433 * New hosts supported (not targets)
7435 IBM RT/PC: romp-ibm-aix or rtpc
7437 * New targets supported (not hosts)
7439 AMD 29000 embedded with COFF a29k-none-coff
7440 AMD 29000 embedded with a.out a29k-none-aout
7441 Ultracomputer remote kernel debug a29k-nyu-kern
7443 * New remote interfaces
7449 *** Changes in GDB-4.0:
7453 Wide output is wrapped at good places to make the output more readable.
7455 Gdb now supports cross-debugging from a host machine of one type to a
7456 target machine of another type. Communication with the target system
7457 is over serial lines. The ``target'' command handles connecting to the
7458 remote system; the ``load'' command will download a program into the
7459 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7460 also supports debugging of realtime processes running under VxWorks,
7461 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7462 stub on the target system.
7464 New CPUs supported include the AMD 29000 and Intel 960.
7466 GDB now reads object files and symbol tables via a ``binary file''
7467 library, which allows a single copy of GDB to debug programs of multiple
7468 object file types such as a.out and coff.
7470 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7471 refcard.dvi and refcard.ps are available to format it).
7474 * Control-Variable user interface simplified
7476 All variables that control the operation of the debugger can be set
7477 by the ``set'' command, and displayed by the ``show'' command.
7479 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7480 ``Show prompt'' produces the response:
7481 Gdb's prompt is new-gdb=>.
7483 What follows are the NEW set commands. The command ``help set'' will
7484 print a complete list of old and new set commands. ``help set FOO''
7485 will give a longer description of the variable FOO. ``show'' will show
7486 all of the variable descriptions and their current settings.
7488 confirm on/off: Enables warning questions for operations that are
7489 hard to recover from, e.g. rerunning the program while
7490 it is already running. Default is ON.
7492 editing on/off: Enables EMACS style command line editing
7493 of input. Previous lines can be recalled with
7494 control-P, the current line can be edited with control-B,
7495 you can search for commands with control-R, etc.
7498 history filename NAME: NAME is where the gdb command history
7499 will be stored. The default is .gdb_history,
7500 or the value of the environment variable
7503 history size N: The size, in commands, of the command history. The
7504 default is 256, or the value of the environment variable
7507 history save on/off: If this value is set to ON, the history file will
7508 be saved after exiting gdb. If set to OFF, the
7509 file will not be saved. The default is OFF.
7511 history expansion on/off: If this value is set to ON, then csh-like
7512 history expansion will be performed on
7513 command line input. The default is OFF.
7515 radix N: Sets the default radix for input and output. It can be set
7516 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7517 in the current radix, so "set radix 10" is always a no-op.
7519 height N: This integer value is the number of lines on a page. Default
7520 is 24, the current `stty rows'' setting, or the ``li#''
7521 setting from the termcap entry matching the environment
7524 width N: This integer value is the number of characters on a line.
7525 Default is 80, the current `stty cols'' setting, or the ``co#''
7526 setting from the termcap entry matching the environment
7529 Note: ``set screensize'' is obsolete. Use ``set height'' and
7530 ``set width'' instead.
7532 print address on/off: Print memory addresses in various command displays,
7533 such as stack traces and structure values. Gdb looks
7534 more ``symbolic'' if you turn this off; it looks more
7535 ``machine level'' with it on. Default is ON.
7537 print array on/off: Prettyprint arrays. New convenient format! Default
7540 print demangle on/off: Print C++ symbols in "source" form if on,
7543 print asm-demangle on/off: Same, for assembler level printouts
7546 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7549 * Support for Epoch Environment.
7551 The epoch environment is a version of Emacs v18 with windowing. One
7552 new command, ``inspect'', is identical to ``print'', except that if you
7553 are running in the epoch environment, the value is printed in its own
7557 * Support for Shared Libraries
7559 GDB can now debug programs and core files that use SunOS shared libraries.
7560 Symbols from a shared library cannot be referenced
7561 before the shared library has been linked with the program (this
7562 happens after you type ``run'' and before the function main() is entered).
7563 At any time after this linking (including when examining core files
7564 from dynamically linked programs), gdb reads the symbols from each
7565 shared library when you type the ``sharedlibrary'' command.
7566 It can be abbreviated ``share''.
7568 sharedlibrary REGEXP: Load shared object library symbols for files
7569 matching a unix regular expression. No argument
7570 indicates to load symbols for all shared libraries.
7572 info sharedlibrary: Status of loaded shared libraries.
7577 A watchpoint stops execution of a program whenever the value of an
7578 expression changes. Checking for this slows down execution
7579 tremendously whenever you are in the scope of the expression, but is
7580 quite useful for catching tough ``bit-spreader'' or pointer misuse
7581 problems. Some machines such as the 386 have hardware for doing this
7582 more quickly, and future versions of gdb will use this hardware.
7584 watch EXP: Set a watchpoint (breakpoint) for an expression.
7586 info watchpoints: Information about your watchpoints.
7588 delete N: Deletes watchpoint number N (same as breakpoints).
7589 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7590 enable N: Re-enables watchpoint number N (same as breakpoints).
7593 * C++ multiple inheritance
7595 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7598 * C++ exception handling
7600 Gdb now supports limited C++ exception handling. Besides the existing
7601 ability to breakpoint on an exception handler, gdb can breakpoint on
7602 the raising of an exception (before the stack is peeled back to the
7605 catch FOO: If there is a FOO exception handler in the dynamic scope,
7606 set a breakpoint to catch exceptions which may be raised there.
7607 Multiple exceptions (``catch foo bar baz'') may be caught.
7609 info catch: Lists all exceptions which may be caught in the
7610 current stack frame.
7613 * Minor command changes
7615 The command ``call func (arg, arg, ...)'' now acts like the print
7616 command, except it does not print or save a value if the function's result
7617 is void. This is similar to dbx usage.
7619 The ``up'' and ``down'' commands now always print the frame they end up
7620 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7621 frames without printing.
7623 * New directory command
7625 'dir' now adds directories to the FRONT of the source search path.
7626 The path starts off empty. Source files that contain debug information
7627 about the directory in which they were compiled can be found even
7628 with an empty path; Sun CC and GCC include this information. If GDB can't
7629 find your source file in the current directory, type "dir .".
7631 * Configuring GDB for compilation
7633 For normal use, type ``./configure host''. See README or gdb.texinfo
7636 GDB now handles cross debugging. If you are remotely debugging between
7637 two different machines, type ``./configure host -target=targ''.
7638 Host is the machine where GDB will run; targ is the machine
7639 where the program that you are debugging will run.