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.
37 * New convenience variable $_ada_exception holds the address of the
38 Ada exception being thrown. This is set by Ada-related catchpoints.
42 ** The gdb.Value type has a new method 'format_string' which returns a
43 string representing the value. The formatting is controlled by the
44 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
45 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
46 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
48 ** gdb.Type has a new property 'objfile' which returns the objfile the
51 ** The frame information printed by the python frame filtering code
52 is now consistent with what the 'backtrace' command prints when
53 there are no filters, or when the 'backtrace' '-no-filters' option
56 ** The new function gdb.lookup_static_symbol can be used to look up
57 symbols with static linkage.
59 ** gdb.Objfile has new methods 'lookup_global_symbol' and
60 'lookup_static_symbol' to lookup a symbol from this objfile only.
62 ** gdb.Block now supports the dictionary syntax for accessing symbols in
63 this block (e.g. block['local_variable']).
67 | [COMMAND] | SHELL_COMMAND
68 | -d DELIM COMMAND DELIM SHELL_COMMAND
69 pipe [COMMAND] | SHELL_COMMAND
70 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
71 Executes COMMAND and sends its output to SHELL_COMMAND.
72 With no COMMAND, repeat the last executed command
73 and send its output to SHELL_COMMAND.
75 with SETTING [VALUE] [-- COMMAND]
76 w SETTING [VALUE] [-- COMMAND]
77 Temporarily set SETTING, run COMMAND, and restore SETTING.
78 Usage: with SETTING -- COMMAND
79 With no COMMAND, repeats the last executed command.
80 SETTING is any GDB setting you can change with the "set"
81 subcommands. For example, 'with language c -- print someobj'
82 temporarily switches to the C language in order to print someobj.
83 Settings can be combined: 'w lang c -- w print elements unlimited --
84 usercmd' switches to the C language and runs usercmd with no limit
85 of array elements to print.
87 maint with SETTING [VALUE] [-- COMMAND]
88 Like "with", but works with "maintenance set" settings.
90 set may-call-functions [on|off]
91 show may-call-functions
92 This controls whether GDB will attempt to call functions in
93 the program, such as with expressions in the print command. It
94 defaults to on. Calling functions in the program being debugged
95 can have undesired side effects. It is now possible to forbid
96 such function calls. If function calls are forbidden, GDB will throw
97 an error when a command (such as print expression) calls a function
100 set print finish [on|off]
102 This controls whether the `finish' command will display the value
103 that is returned by the current function. When `off', the value is
104 still entered into the value history, but it is not printed. The
109 Allows deeply nested structures to be simplified when printing by
110 replacing deeply nested parts (beyond the max-depth) with ellipses.
111 The default max-depth is 20, but this can be set to unlimited to get
112 the old behavior back.
114 set logging debugredirect [on|off]
115 By default, GDB debug output will go to both the terminal and the logfile.
116 Set if you want debug output to go only to the log file.
118 set style title foreground COLOR
119 set style title background COLOR
120 set style title intensity VALUE
121 Control the styling of titles.
123 set style highlight foreground COLOR
124 set style highlight background COLOR
125 set style highlight intensity VALUE
126 Control the styling of highlightings.
128 maint set test-settings KIND
129 maint show test-settings KIND
130 A set of commands used by the testsuite for exercising the settings
133 set print frame-info [short-location|location|location-and-address
134 |source-and-location|source-line|auto]
135 show print frame-info
136 This controls what frame information is printed by the commands printing
137 a frame. This setting will e.g. influence the behaviour of 'backtrace',
138 'frame', 'stepi'. The python frame filtering also respect this setting.
139 The 'backtrace' '-frame-info' option can override this global setting.
144 The "help" command uses the title style to enhance the
145 readibility of its output by styling the classes and
149 Similarly to "help", the "apropos" command also uses the
150 title style for the command names. "apropos" accepts now
151 a flag "-v" (verbose) to show the full documentation
152 of matching commands and to use the highlight style to mark
153 the documentation parts matching REGEXP.
157 The GDB printf and eval commands can now print C-style and Ada-style
158 string convenience variables without calling functions in the program.
159 This allows to do formatted printing of strings without having
160 a running inferior, or when debugging a core dump.
162 info sources [-dirname | -basename] [--] [REGEXP]
163 This command has now optional arguments to only print the files
164 whose names match REGEXP. The arguments -dirname and -basename
165 allow to restrict matching respectively to the dirname and basename
169 The "show style" and its subcommands are now styling
170 a style name in their output using its own style, to help
171 the user visualize the different styles.
173 set print frame-arguments
174 The new value 'presence' indicates to only indicate the presence of
175 arguments using ..., instead of printing argument names and values.
177 set print raw-frame-arguments
178 show print raw-frame-arguments
180 These commands replace the similarly-named "set/show print raw
181 frame-arguments" commands (now with a dash instead of a space). The
182 old commands are now deprecated and may be removed in a future
185 maint test-options require-delimiter
186 maint test-options unknown-is-error
187 maint test-options unknown-is-operand
188 maint show test-options-completion-result
189 Commands used by the testsuite to validate the command options
192 focus, winheight, +, -, >, <
193 These commands are now case-sensitive.
195 * New command options, command completion
197 GDB now has a standard infrastructure to support dash-style command
198 options ('-OPT'). One benefit is that commands that use it can
199 easily support completion of command line arguments. Try "CMD
200 -[TAB]" or "help CMD" to find options supported by a command. Over
201 time, we intend to migrate most commands to this infrastructure. A
202 number of commands got support for new command options in this
205 ** The "print" and "compile print" commands now support a number of
206 options that allow overriding relevant global print settings as
207 set by "set print" subcommands:
211 -array-indexes [on|off]
212 -elements NUMBER|unlimited
216 -repeats NUMBER|unlimited
217 -static-members [on|off]
222 Note that because the "print"/"compile print" commands accept
223 arbitrary expressions which may look like options (including
224 abbreviations), if you specify any command option, then you must
225 use a double dash ("--") to mark the end of argument processing.
227 ** The "backtrace" command now supports a number of options that
228 allow overriding relevant global print settings as set by "set
229 backtrace" and "set print" subcommands:
231 -entry-values no|only|preferred|if-needed|both|compact|default
232 -frame-arguments all|scalars|none
233 -raw-frame-arguments [on|off]
234 -frame-info auto|source-line|location|source-and-location
235 |location-and-address|short-location
239 In addition, the full/no-filters/hide qualifiers are now also
240 exposed as command options too:
246 ** The "frame apply", "tfaas" and "faas" commands similarly now
247 support the following options:
252 ** The new "info sources" options -dirname and -basename options
253 are using the standard '-OPT' infrastructure.
255 All options above can also be abbreviated. The argument of boolean
256 (on/off) options can be 0/1 too, and also the argument is assumed
257 "on" if omitted. This allows writing compact command invocations,
260 (gdb) p -r -p -o 0 -- *myptr
262 The above is equivalent to:
264 (gdb) print -raw -pretty -object off -- *myptr
266 ** The "info types" command now supports the '-q' flag to disable
267 printing of some header information in a similar fashion to "info
268 variables" and "info functions".
270 ** The "info variables", "info functions", and "whereis" commands
271 now take a '-n' flag that excludes non-debug symbols (symbols
272 from the symbol table, not from the debug info such as DWARF)
275 * Completion improvements
277 ** GDB can now complete the options of the "thread apply all" and
278 "taas" commands, and their "-ascending" option can now be
281 ** GDB can now complete the options of the "info threads", "info
282 functions", "info variables", "info locals", and "info args"
285 ** GDB can now complete the options of the "compile file" and
286 "compile code" commands. The "compile file" command now
287 completes on filenames.
289 ** GDB can now complete the backtrace command's
290 "full/no-filters/hide" qualifiers.
292 * In settings, you can now abbreviate "unlimited".
294 E.g., "set print elements u" is now equivalent to "set print
300 This lists all the possible completions for the rest of the line, if it
301 were to be given as a command itself. This is intended for use by MI
302 frontends in cases when separate CLI and MI channels cannot be used.
304 -catch-throw, -catch-rethrow, and -catch-catch
305 These can be used to catch C++ exceptions in a similar fashion to
306 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
310 ** The default version of the MI interpreter is now 3 (-i=mi3).
312 ** The output of information about multi-location breakpoints (which is
313 syntactically incorrect in MI 2) has changed in MI 3. This affects
314 the following commands and events:
318 - =breakpoint-created
319 - =breakpoint-modified
321 The -fix-multi-location-breakpoint-output command can be used to enable
322 this behavior with previous MI versions.
324 ** Backtraces and frames include a new optional field addr_flags which is
325 given after the addr field. On AArch64 this contains PAC if the address
326 has been masked in the frame. On all other targets the field is not
331 The testsuite now creates the files gdb.cmd (containing the arguments
332 used to launch GDB) and gdb.in (containing all the commands sent to
333 GDB) in the output directory for each test script. Multiple invocations
334 are appended with .1, .2, .3 etc.
336 * Building GDB and GDBserver now requires GNU make >= 3.82.
338 Using another implementation of the make program or an earlier version of
339 GNU make to build GDB or GDBserver is not supported.
341 * Building GDB now requires GNU readline >= 7.0.
343 GDB now bundles GNU readline 8.0, but if you choose to use
344 --with-system-readline, only readline >= 7.0 can be used.
346 * The TUI SingleKey keymap is now named "SingleKey". This can be used
347 from .inputrc to bind keys in this keymap. This feature is only
348 available when gdb is built against GNU readline 8.0 or later.
350 * Removed targets and native configurations
352 GDB no longer supports debugging the Cell Broadband Engine. This includes
353 both debugging standalone Cell/B.E. SPU applications and integrated debugging
354 of Cell/B.E. applications that use both the PPU and SPU architectures.
360 *** Changes in GDB 8.3
362 * GDB and GDBserver now support access to additional registers on
363 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
366 * GDB now has experimental support for the compilation and injection of
367 C++ source code into the inferior. This beta release does not include
368 support for several language features, such as templates, constructors,
371 This feature requires GCC 7.1 or higher built with libcp1.so
374 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
375 can be passed using the '[ADDRESS]:PORT' notation, or the regular
376 'ADDRESS:PORT' method.
378 * DWARF index cache: GDB can now automatically save indices of DWARF
379 symbols on disk to speed up further loading of the same binaries.
381 * Ada task switching is now supported on aarch64-elf targets when
382 debugging a program using the Ravenscar Profile. For more information,
383 see the "Tasking Support when using the Ravenscar Profile" section
384 in the GDB user manual.
386 * GDB in batch mode now exits with status 1 if the last command to be
389 * The RISC-V target now supports target descriptions.
391 * System call catchpoints now support system call aliases on FreeBSD.
392 When the ABI of a system call changes in FreeBSD, this is
393 implemented by leaving a compatibility system call using the old ABI
394 at the existing number and allocating a new system call number for
395 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
396 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
397 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
398 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
399 so that a system call catchpoint for the 'kevent' system call will
400 catch invocations of both the 'kevent' and 'freebsd11_kevent'
401 binaries. This ensures that 'kevent' system calls are caught for
402 binaries using either the old or new ABIs.
404 * Terminal styling is now available for the CLI and the TUI. GNU
405 Source Highlight can additionally be used to provide styling of
406 source code snippets. See the "set style" commands, below, for more
409 * Removed support for old demangling styles arm, edg, gnu, hp and
414 set debug compile-cplus-types
415 show debug compile-cplus-types
416 Control the display of debug output about type conversion in the
417 C++ compile feature. Commands have no effect while compiliong
422 Control whether debug output about files/functions skipping is
425 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
426 Apply a command to some frames.
427 FLAG arguments allow to control what output to produce and how to handle
428 errors raised when applying COMMAND to a frame.
431 Apply a command to all threads (ignoring errors and empty output).
432 Shortcut for 'thread apply all -s COMMAND'.
435 Apply a command to all frames (ignoring errors and empty output).
436 Shortcut for 'frame apply all -s COMMAND'.
439 Apply a command to all frames of all threads (ignoring errors and empty
441 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
443 maint set dwarf unwinders (on|off)
444 maint show dwarf unwinders
445 Control whether DWARF unwinders can be used.
448 Display a list of open files for a process.
452 Changes to the "frame", "select-frame", and "info frame" CLI commands.
453 These commands all now take a frame specification which
454 is either a frame level, or one of the keywords 'level', 'address',
455 'function', or 'view' followed by a parameter. Selecting a frame by
456 address, or viewing a frame outside the current backtrace now
457 requires the use of a keyword. Selecting a frame by level is
458 unchanged. The MI comment "-stack-select-frame" is unchanged.
460 target remote FILENAME
461 target extended-remote FILENAME
462 If FILENAME is a Unix domain socket, GDB will attempt to connect
463 to this socket instead of opening FILENAME as a character device.
465 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
466 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
467 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
468 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
469 These commands can now print only the searched entities
470 matching the provided regexp(s), giving a condition
471 on the entity names or entity types. The flag -q disables
472 printing headers or informations messages.
478 These commands now determine the syntax for the shown entities
479 according to the language chosen by `set language'. In particular,
480 `set language auto' means to automatically choose the language of
483 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
484 The 'thread apply' command accepts new FLAG arguments.
485 FLAG arguments allow to control what output to produce and how to handle
486 errors raised when applying COMMAND to a thread.
488 set tui tab-width NCHARS
489 show tui tab-width NCHARS
490 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
492 set style enabled [on|off]
494 Enable or disable terminal styling. Styling is enabled by default
495 on most hosts, but disabled by default when in batch mode.
497 set style sources [on|off]
499 Enable or disable source code styling. Source code styling is
500 enabled by default, but only takes effect if styling in general is
501 enabled, and if GDB was linked with GNU Source Highlight.
503 set style filename foreground COLOR
504 set style filename background COLOR
505 set style filename intensity VALUE
506 Control the styling of file names.
508 set style function foreground COLOR
509 set style function background COLOR
510 set style function intensity VALUE
511 Control the styling of function names.
513 set style variable foreground COLOR
514 set style variable background COLOR
515 set style variable intensity VALUE
516 Control the styling of variable names.
518 set style address foreground COLOR
519 set style address background COLOR
520 set style address intensity VALUE
521 Control the styling of addresses.
525 ** The '-data-disassemble' MI command now accepts an '-a' option to
526 disassemble the whole function surrounding the given program
527 counter value or function name. Support for this feature can be
528 verified by using the "-list-features" command, which should
529 contain "data-disassemble-a-option".
531 ** Command responses and notifications that include a frame now include
532 the frame's architecture in a new "arch" attribute.
534 * New native configurations
536 GNU/Linux/RISC-V riscv*-*-linux*
537 FreeBSD/riscv riscv*-*-freebsd*
541 GNU/Linux/RISC-V riscv*-*-linux*
543 CSKY GNU/LINUX csky*-*-linux
544 FreeBSD/riscv riscv*-*-freebsd*
546 GNU/Linux/OpenRISC or1k*-*-linux*
550 GDB no longer supports native debugging on versions of MS-Windows
555 ** GDB no longer supports Python versions less than 2.6.
557 ** The gdb.Inferior type has a new 'progspace' property, which is the program
558 space associated to that inferior.
560 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
561 of objfiles associated to that program space.
563 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
564 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
567 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
568 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
569 correct and did not work properly.
571 ** The gdb.Value type has a new constructor, which is used to construct a
572 gdb.Value from a Python buffer object and a gdb.Type.
578 Enable or disable the undefined behavior sanitizer. This is
579 disabled by default, but passing --enable-ubsan=yes or
580 --enable-ubsan=auto to configure will enable it. Enabling this can
581 cause a performance penalty. The undefined behavior sanitizer was
582 first introduced in GCC 4.9.
584 *** Changes in GDB 8.2
586 * The 'set disassembler-options' command now supports specifying options
589 * The 'symbol-file' command now accepts an '-o' option to add a relative
590 offset to all sections.
592 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
593 a relative offset to all sections, but it allows to override the load
594 address of individual sections using '-s'.
596 * The 'add-symbol-file' command no longer requires the second argument
597 (address of the text section).
599 * The endianness used with the 'set endian auto' mode in the absence of
600 an executable selected for debugging is now the last endianness chosen
601 either by one of the 'set endian big' and 'set endian little' commands
602 or by inferring from the last executable used, rather than the startup
605 * The pager now allows a "c" response, meaning to disable the pager
606 for the rest of the current command.
608 * The commands 'info variables/functions/types' now show the source line
609 numbers of symbol definitions when available.
611 * 'info proc' now works on running processes on FreeBSD systems and core
612 files created on FreeBSD systems.
614 * C expressions can now use _Alignof, and C++ expressions can now use
617 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
618 the vector length while the process is running.
624 Control display of debugging info regarding the FreeBSD native target.
626 set|show varsize-limit
627 This new setting allows the user to control the maximum size of Ada
628 objects being printed when those objects have a variable type,
629 instead of that maximum size being hardcoded to 65536 bytes.
631 set|show record btrace cpu
632 Controls the processor to be used for enabling errata workarounds for
635 maint check libthread-db
636 Run integrity checks on the current inferior's thread debugging
639 maint set check-libthread-db (on|off)
640 maint show check-libthread-db
641 Control whether to run integrity checks on inferior specific thread
642 debugging libraries as they are loaded. The default is not to
647 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
649 ** The commands attached to a breakpoint can be set by assigning to
650 the breakpoint's "commands" field.
652 ** gdb.execute can now execute multi-line gdb commands.
654 ** The new functions gdb.convenience_variable and
655 gdb.set_convenience_variable can be used to get and set the value
656 of convenience variables.
658 ** A gdb.Parameter will no longer print the "set" help text on an
659 ordinary "set"; instead by default a "set" will be silent unless
660 the get_set_string method returns a non-empty string.
664 RiscV ELF riscv*-*-elf
666 * Removed targets and native configurations
668 m88k running OpenBSD m88*-*-openbsd*
669 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
670 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
671 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
673 * Aarch64/Linux hardware watchpoints improvements
675 Hardware watchpoints on unaligned addresses are now properly
676 supported when running Linux kernel 4.10 or higher: read and access
677 watchpoints are no longer spuriously missed, and all watchpoints
678 lengths between 1 and 8 bytes are supported. On older kernels,
679 watchpoints set on unaligned addresses are no longer missed, with
680 the tradeoff that there is a possibility of false hits being
685 --enable-codesign=CERT
686 This can be used to invoke "codesign -s CERT" after building gdb.
687 This option is useful on macOS, where code signing is required for
688 gdb to work properly.
690 --disable-gdbcli has been removed
691 This is now silently accepted, but does nothing.
693 *** Changes in GDB 8.1
695 * GDB now supports dynamically creating arbitrary register groups specified
696 in XML target descriptions. This allows for finer grain grouping of
697 registers on systems with a large amount of registers.
699 * The 'ptype' command now accepts a '/o' flag, which prints the
700 offsets and sizes of fields in a struct, like the pahole(1) tool.
702 * New "--readnever" command line option instructs GDB to not read each
703 symbol file's symbolic debug information. This makes startup faster
704 but at the expense of not being able to perform symbolic debugging.
705 This option is intended for use cases where symbolic debugging will
706 not be used, e.g., when you only need to dump the debuggee's core.
708 * GDB now uses the GNU MPFR library, if available, to emulate target
709 floating-point arithmetic during expression evaluation when the target
710 uses different floating-point formats than the host. At least version
711 3.1 of GNU MPFR is required.
713 * GDB now supports access to the guarded-storage-control registers and the
714 software-based guarded-storage broadcast control registers on IBM z14.
716 * On Unix systems, GDB now supports transmitting environment variables
717 that are to be set or unset to GDBserver. These variables will
718 affect the environment to be passed to the remote inferior.
720 To inform GDB of environment variables that are to be transmitted to
721 GDBserver, use the "set environment" command. Only user set
722 environment variables are sent to GDBserver.
724 To inform GDB of environment variables that are to be unset before
725 the remote inferior is started by the GDBserver, use the "unset
726 environment" command.
728 * Completion improvements
730 ** GDB can now complete function parameters in linespecs and
731 explicit locations without quoting. When setting breakpoints,
732 quoting around functions names to help with TAB-completion is
733 generally no longer necessary. For example, this now completes
736 (gdb) b function(in[TAB]
737 (gdb) b function(int)
739 Related, GDB is no longer confused with completing functions in
740 C++ anonymous namespaces:
743 (gdb) b (anonymous namespace)::[TAB][TAB]
744 (anonymous namespace)::a_function()
745 (anonymous namespace)::b_function()
747 ** GDB now has much improved linespec and explicit locations TAB
748 completion support, that better understands what you're
749 completing and offers better suggestions. For example, GDB no
750 longer offers data symbols as possible completions when you're
751 setting a breakpoint.
753 ** GDB now TAB-completes label symbol names.
755 ** The "complete" command now mimics TAB completion accurately.
757 * New command line options (gcore)
760 Dump all memory mappings.
762 * Breakpoints on C++ functions are now set on all scopes by default
764 By default, breakpoints on functions/methods are now interpreted as
765 specifying all functions with the given name ignoring missing
766 leading scopes (namespaces and classes).
768 For example, assuming a C++ program with symbols named:
773 both commands "break func()" and "break B::func()" set a breakpoint
776 You can use the new flag "-qualified" to override this. This makes
777 GDB interpret the specified function name as a complete
778 fully-qualified name instead. For example, using the same C++
779 program, the "break -q B::func" command sets a breakpoint on
780 "B::func", only. A parameter has been added to the Python
781 gdb.Breakpoint constructor to achieve the same result when creating
782 a breakpoint from Python.
784 * Breakpoints on functions marked with C++ ABI tags
786 GDB can now set breakpoints on functions marked with C++ ABI tags
787 (e.g., [abi:cxx11]). See here for a description of ABI tags:
788 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
790 Functions with a C++11 abi tag are demangled/displayed like this:
792 function[abi:cxx11](int)
795 You can now set a breakpoint on such functions simply as if they had
798 (gdb) b function(int)
800 Or if you need to disambiguate between tags, like:
802 (gdb) b function[abi:other_tag](int)
804 Tab completion was adjusted accordingly as well.
808 ** New events gdb.new_inferior, gdb.inferior_deleted, and
809 gdb.new_thread are emitted. See the manual for further
810 description of these.
812 ** A new function, "gdb.rbreak" has been added to the Python API.
813 This function allows the setting of a large number of breakpoints
814 via a regex pattern in Python. See the manual for further details.
816 ** Python breakpoints can now accept explicit locations. See the
817 manual for a further description of this feature.
820 * New features in the GDB remote stub, GDBserver
822 ** GDBserver is now able to start inferior processes with a
823 specified initial working directory.
825 The user can set the desired working directory to be used from
826 GDB using the new "set cwd" command.
828 ** New "--selftest" command line option runs some GDBserver self
829 tests. These self tests are disabled in releases.
831 ** On Unix systems, GDBserver now does globbing expansion and variable
832 substitution in inferior command line arguments.
834 This is done by starting inferiors using a shell, like GDB does.
835 See "set startup-with-shell" in the user manual for how to disable
836 this from GDB when using "target extended-remote". When using
837 "target remote", you can disable the startup with shell by using the
838 new "--no-startup-with-shell" GDBserver command line option.
840 ** On Unix systems, GDBserver now supports receiving environment
841 variables that are to be set or unset from GDB. These variables
842 will affect the environment to be passed to the inferior.
844 * When catching an Ada exception raised with a message, GDB now prints
845 the message in the catchpoint hit notification. In GDB/MI mode, that
846 information is provided as an extra field named "exception-message"
847 in the *stopped notification.
849 * Trait objects can now be inspected When debugging Rust code. This
850 requires compiler support which will appear in Rust 1.24.
854 QEnvironmentHexEncoded
855 Inform GDBserver of an environment variable that is to be passed to
856 the inferior when starting it.
859 Inform GDBserver of an environment variable that is to be unset
860 before starting the remote inferior.
863 Inform GDBserver that the environment should be reset (i.e.,
864 user-set environment variables should be unset).
867 Indicates whether the inferior must be started with a shell or not.
870 Tell GDBserver that the inferior to be started should use a specific
873 * The "maintenance print c-tdesc" command now takes an optional
874 argument which is the file name of XML target description.
876 * The "maintenance selftest" command now takes an optional argument to
877 filter the tests to be run.
879 * The "enable", and "disable" commands now accept a range of
880 breakpoint locations, e.g. "enable 1.3-5".
885 Set and show the current working directory for the inferior.
888 Set and show compilation command used for compiling and injecting code
889 with the 'compile' commands.
891 set debug separate-debug-file
892 show debug separate-debug-file
893 Control the display of debug output about separate debug file search.
895 set dump-excluded-mappings
896 show dump-excluded-mappings
897 Control whether mappings marked with the VM_DONTDUMP flag should be
898 dumped when generating a core file.
901 List the registered selftests.
904 Start the debugged program stopping at the first instruction.
907 Control display of debugging messages related to OpenRISC targets.
909 set|show print type nested-type-limit
910 Set and show the limit of nesting level for nested types that the
911 type printer will show.
913 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
916 * Safer/improved support for debugging with no debug info
918 GDB no longer assumes functions with no debug information return
921 This means that GDB now refuses to call such functions unless you
922 tell it the function's type, by either casting the call to the
923 declared return type, or by casting the function to a function
924 pointer of the right type, and calling that:
926 (gdb) p getenv ("PATH")
927 'getenv' has unknown return type; cast the call to its declared return type
928 (gdb) p (char *) getenv ("PATH")
929 $1 = 0x7fffffffe "/usr/local/bin:/"...
930 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
931 $2 = 0x7fffffffe "/usr/local/bin:/"...
933 Similarly, GDB no longer assumes that global variables with no debug
934 info have type 'int', and refuses to print the variable's value
935 unless you tell it the variable's type:
938 'var' has unknown type; cast it to its declared type
942 * New native configurations
944 FreeBSD/aarch64 aarch64*-*-freebsd*
945 FreeBSD/arm arm*-*-freebsd*
949 FreeBSD/aarch64 aarch64*-*-freebsd*
950 FreeBSD/arm arm*-*-freebsd*
951 OpenRISC ELF or1k*-*-elf
953 * Removed targets and native configurations
955 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
957 *** Changes in GDB 8.0
959 * GDB now supports access to the PKU register on GNU/Linux. The register is
960 added by the Memory Protection Keys for Userspace feature which will be
961 available in future Intel CPUs.
963 * GDB now supports C++11 rvalue references.
967 ** New functions to start, stop and access a running btrace recording.
968 ** Rvalue references are now supported in gdb.Type.
970 * GDB now supports recording and replaying rdrand and rdseed Intel 64
973 * Building GDB and GDBserver now requires a C++11 compiler.
975 For example, GCC 4.8 or later.
977 It is no longer possible to build GDB or GDBserver with a C
978 compiler. The --disable-build-with-cxx configure option has been
981 * Building GDB and GDBserver now requires GNU make >= 3.81.
983 It is no longer supported to build GDB or GDBserver with another
984 implementation of the make program or an earlier version of GNU make.
986 * Native debugging on MS-Windows supports command-line redirection
988 Command-line arguments used for starting programs on MS-Windows can
989 now include redirection symbols supported by native Windows shells,
990 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
991 as "run", "start", and "set args", as well as the corresponding MI
994 * Support for thread names on MS-Windows.
996 GDB now catches and handles the special exception that programs
997 running on MS-Windows use to assign names to threads in the
1000 * Support for Java programs compiled with gcj has been removed.
1002 * User commands now accept an unlimited number of arguments.
1003 Previously, only up to 10 was accepted.
1005 * The "eval" command now expands user-defined command arguments.
1007 This makes it easier to process a variable number of arguments:
1012 eval "print $arg%d", $i
1017 * Target descriptions can now describe registers for sparc32 and sparc64.
1019 * GDB now supports DWARF version 5 (debug information format).
1020 Its .debug_names index is not yet supported.
1022 * New native configurations
1024 FreeBSD/mips mips*-*-freebsd
1028 Synopsys ARC arc*-*-elf32
1029 FreeBSD/mips mips*-*-freebsd
1031 * Removed targets and native configurations
1033 Alpha running FreeBSD alpha*-*-freebsd*
1034 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1039 Erases all the flash memory regions reported by the target.
1041 maint print arc arc-instruction address
1042 Print internal disassembler information about instruction at a given address.
1046 set disassembler-options
1047 show disassembler-options
1048 Controls the passing of target specific information to the disassembler.
1049 If it is necessary to specify more than one disassembler option then
1050 multiple options can be placed together into a comma separated list.
1051 The default value is the empty string. Currently, the only supported
1052 targets are ARM, PowerPC and S/390.
1057 Erases all the flash memory regions reported by the target. This is
1058 equivalent to the CLI command flash-erase.
1060 -file-list-shared-libraries
1061 List the shared libraries in the program. This is
1062 equivalent to the CLI command "info shared".
1065 Catchpoints stopping the program when Ada exceptions are
1066 handled. This is equivalent to the CLI command "catch handlers".
1068 *** Changes in GDB 7.12
1070 * GDB and GDBserver now build with a C++ compiler by default.
1072 The --enable-build-with-cxx configure option is now enabled by
1073 default. One must now explicitly configure with
1074 --disable-build-with-cxx in order to build with a C compiler. This
1075 option will be removed in a future release.
1077 * GDBserver now supports recording btrace without maintaining an active
1080 * GDB now supports a negative repeat count in the 'x' command to examine
1081 memory backward from the given address. For example:
1084 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1085 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1086 (gdb) x/-5i 0x0000000000400580
1087 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1088 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1089 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1090 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1091 0x40057b <main(int, char**)+25>:
1092 callq 0x400536 <Func1(int, char const*)>
1094 * Fortran: Support structures with fields of dynamic types and
1095 arrays of dynamic types.
1097 * The symbol dumping maintenance commands have new syntax.
1098 maint print symbols [-pc address] [--] [filename]
1099 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1100 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1101 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1102 maint print msymbols [-objfile objfile] [--] [filename]
1104 * GDB now supports multibit bitfields and enums in target register
1107 * New Python-based convenience function $_as_string(val), which returns
1108 the textual representation of a value. This function is especially
1109 useful to obtain the text label of an enum value.
1111 * Intel MPX bound violation handling.
1113 Segmentation faults caused by a Intel MPX boundary violation
1114 now display the kind of violation (upper or lower), the memory
1115 address accessed and the memory bounds, along with the usual
1116 signal received and code location.
1120 Program received signal SIGSEGV, Segmentation fault
1121 Upper bound violation while accessing address 0x7fffffffc3b3
1122 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1123 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1125 * Rust language support.
1126 GDB now supports debugging programs written in the Rust programming
1127 language. See https://www.rust-lang.org/ for more information about
1130 * Support for running interpreters on specified input/output devices
1132 GDB now supports a new mechanism that allows frontends to provide
1133 fully featured GDB console views, as a better alternative to
1134 building such views on top of the "-interpreter-exec console"
1135 command. See the new "new-ui" command below. With that command,
1136 frontends can now start GDB in the traditional command-line mode
1137 running in an embedded terminal emulator widget, and create a
1138 separate MI interpreter running on a specified i/o device. In this
1139 way, GDB handles line editing, history, tab completion, etc. in the
1140 console all by itself, and the GUI uses the separate MI interpreter
1141 for its own control and synchronization, invisible to the command
1144 * The "catch syscall" command catches groups of related syscalls.
1146 The "catch syscall" command now supports catching a group of related
1147 syscalls using the 'group:' or 'g:' prefix.
1152 skip -gfile file-glob-pattern
1153 skip -function function
1154 skip -rfunction regular-expression
1155 A generalized form of the skip command, with new support for
1156 glob-style file names and regular expressions for function names.
1157 Additionally, a file spec and a function spec may now be combined.
1159 maint info line-table REGEXP
1160 Display the contents of GDB's internal line table data struture.
1163 Run any GDB unit tests that were compiled in.
1166 Start a new user interface instance running INTERP as interpreter,
1167 using the TTY file for input/output.
1171 ** gdb.Breakpoint objects have a new attribute "pending", which
1172 indicates whether the breakpoint is pending.
1173 ** Three new breakpoint-related events have been added:
1174 gdb.breakpoint_created, gdb.breakpoint_modified, and
1175 gdb.breakpoint_deleted.
1177 signal-event EVENTID
1178 Signal ("set") the given MS-Windows event object. This is used in
1179 conjunction with the Windows JIT debugging (AeDebug) support, where
1180 the OS suspends a crashing process until a debugger can attach to
1181 it. Resuming the crashing process, in order to debug it, is done by
1182 signalling an event.
1184 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1185 was added in GDBserver, including JIT compiling fast tracepoint's
1186 conditional expression bytecode into native code.
1188 * Support for various remote target protocols and ROM monitors has
1191 target m32rsdi Remote M32R debugging over SDI
1192 target mips MIPS remote debugging protocol
1193 target pmon PMON ROM monitor
1194 target ddb NEC's DDB variant of PMON for Vr4300
1195 target rockhopper NEC RockHopper variant of PMON
1196 target lsi LSI variant of PMO
1198 * Support for tracepoints and fast tracepoints on powerpc-linux,
1199 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1200 including JIT compiling fast tracepoint's conditional expression
1201 bytecode into native code.
1203 * MI async record =record-started now includes the method and format used for
1204 recording. For example:
1206 =record-started,thread-group="i1",method="btrace",format="bts"
1208 * MI async record =thread-selected now includes the frame field. For example:
1210 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1214 Andes NDS32 nds32*-*-elf
1216 *** Changes in GDB 7.11
1218 * GDB now supports debugging kernel-based threads on FreeBSD.
1220 * Per-inferior thread numbers
1222 Thread numbers are now per inferior instead of global. If you're
1223 debugging multiple inferiors, GDB displays thread IDs using a
1224 qualified INF_NUM.THR_NUM form. For example:
1228 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1229 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1230 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1231 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1233 As consequence, thread numbers as visible in the $_thread
1234 convenience variable and in Python's InferiorThread.num attribute
1235 are no longer unique between inferiors.
1237 GDB now maintains a second thread ID per thread, referred to as the
1238 global thread ID, which is the new equivalent of thread numbers in
1239 previous releases. See also $_gthread below.
1241 For backwards compatibility, MI's thread IDs always refer to global
1244 * Commands that accept thread IDs now accept the qualified
1245 INF_NUM.THR_NUM form as well. For example:
1248 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1251 * In commands that accept a list of thread IDs, you can now refer to
1252 all threads of an inferior using a star wildcard. GDB accepts
1253 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1254 refer to all threads of the current inferior. For example, "info
1257 * You can use "info threads -gid" to display the global thread ID of
1260 * The new convenience variable $_gthread holds the global number of
1263 * The new convenience variable $_inferior holds the number of the
1266 * GDB now displays the ID and name of the thread that hit a breakpoint
1267 or received a signal, if your program is multi-threaded. For
1270 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1271 Thread 1 "main" received signal SIGINT, Interrupt.
1273 * Record btrace now supports non-stop mode.
1275 * Support for tracepoints on aarch64-linux was added in GDBserver.
1277 * The 'record instruction-history' command now indicates speculative execution
1278 when using the Intel Processor Trace recording format.
1280 * GDB now allows users to specify explicit locations, bypassing
1281 the linespec parser. This feature is also available to GDB/MI
1284 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1285 GDB now is able to debug both AArch64 applications and ARM applications
1288 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1289 including JIT compiling fast tracepoint's conditional expression bytecode
1292 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1294 * "info threads", "info inferiors", "info display", "info checkpoints"
1295 and "maint info program-spaces" now list the corresponding items in
1296 ascending ID order, for consistency with all other "info" commands.
1298 * In Ada, the overloads selection menu has been enhanced to display the
1299 parameter types and the return types for the matching overloaded subprograms.
1303 maint set target-non-stop (on|off|auto)
1304 maint show target-non-stop
1305 Control whether GDB targets always operate in non-stop mode even if
1306 "set non-stop" is "off". The default is "auto", meaning non-stop
1307 mode is enabled if supported by the target.
1309 maint set bfd-sharing
1310 maint show bfd-sharing
1311 Control the reuse of bfd objects.
1314 show debug bfd-cache
1315 Control display of debugging info regarding bfd caching.
1319 Control display of debugging info regarding FreeBSD threads.
1321 set remote multiprocess-extensions-packet
1322 show remote multiprocess-extensions-packet
1323 Set/show the use of the remote protocol multiprocess extensions.
1325 set remote thread-events
1326 show remote thread-events
1327 Set/show the use of thread create/exit events.
1329 set ada print-signatures on|off
1330 show ada print-signatures"
1331 Control whether parameter types and return types are displayed in overloads
1332 selection menus. It is activaled (@code{on}) by default.
1336 Controls the maximum size of memory, in bytes, that GDB will
1337 allocate for value contents. Prevents incorrect programs from
1338 causing GDB to allocate overly large buffers. Default is 64k.
1340 * The "disassemble" command accepts a new modifier: /s.
1341 It prints mixed source+disassembly like /m with two differences:
1342 - disassembled instructions are now printed in program order, and
1343 - and source for all relevant files is now printed.
1344 The "/m" option is now considered deprecated: its "source-centric"
1345 output hasn't proved useful in practice.
1347 * The "record instruction-history" command accepts a new modifier: /s.
1348 It behaves exactly like /m and prints mixed source+disassembly.
1350 * The "set scheduler-locking" command supports a new mode "replay".
1351 It behaves like "off" in record mode and like "on" in replay mode.
1353 * Support for various ROM monitors has been removed:
1355 target dbug dBUG ROM monitor for Motorola ColdFire
1356 target picobug Motorola picobug monitor
1357 target dink32 DINK32 ROM monitor for PowerPC
1358 target m32r Renesas M32R/D ROM monitor
1359 target mon2000 mon2000 ROM monitor
1360 target ppcbug PPCBUG ROM monitor for PowerPC
1362 * Support for reading/writing memory and extracting values on architectures
1363 whose memory is addressable in units of any integral multiple of 8 bits.
1366 Allows to break when an Ada exception is handled.
1368 * New remote packets
1371 Indicates that an exec system call was executed.
1373 exec-events feature in qSupported
1374 The qSupported packet allows GDB to request support for exec
1375 events using the new 'gdbfeature' exec-event, and the qSupported
1376 response can contain the corresponding 'stubfeature'. Set and
1377 show commands can be used to display whether these features are enabled.
1380 Equivalent to interrupting with the ^C character, but works in
1383 thread created stop reason (T05 create:...)
1384 Indicates that the thread was just created and is stopped at entry.
1386 thread exit stop reply (w exitcode;tid)
1387 Indicates that the thread has terminated.
1390 Enables/disables thread create and exit event reporting. For
1391 example, this is used in non-stop mode when GDB stops a set of
1392 threads and synchronously waits for the their corresponding stop
1393 replies. Without exit events, if one of the threads exits, GDB
1394 would hang forever not knowing that it should no longer expect a
1395 stop for that same thread.
1398 Indicates that there are no resumed threads left in the target (all
1399 threads are stopped). The remote stub reports support for this stop
1400 reply to GDB's qSupported query.
1403 Enables/disables catching syscalls from the inferior process.
1404 The remote stub reports support for this packet to GDB's qSupported query.
1406 syscall_entry stop reason
1407 Indicates that a syscall was just called.
1409 syscall_return stop reason
1410 Indicates that a syscall just returned.
1412 * Extended-remote exec events
1414 ** GDB now has support for exec events on extended-remote Linux targets.
1415 For such targets with Linux kernels 2.5.46 and later, this enables
1416 follow-exec-mode and exec catchpoints.
1418 set remote exec-event-feature-packet
1419 show remote exec-event-feature-packet
1420 Set/show the use of the remote exec event feature.
1422 * Thread names in remote protocol
1424 The reply to qXfer:threads:read may now include a name attribute for each
1427 * Target remote mode fork and exec events
1429 ** GDB now has support for fork and exec events on target remote mode
1430 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1431 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1432 fork and exec catchpoints.
1434 * Remote syscall events
1436 ** GDB now has support for catch syscall on remote Linux targets,
1437 currently enabled on x86/x86_64 architectures.
1439 set remote catch-syscall-packet
1440 show remote catch-syscall-packet
1441 Set/show the use of the remote catch syscall feature.
1445 ** The -var-set-format command now accepts the zero-hexadecimal
1446 format. It outputs data in hexadecimal format with zero-padding on the
1451 ** gdb.InferiorThread objects have a new attribute "global_num",
1452 which refers to the thread's global thread ID. The existing
1453 "num" attribute now refers to the thread's per-inferior number.
1454 See "Per-inferior thread numbers" above.
1455 ** gdb.InferiorThread objects have a new attribute "inferior", which
1456 is the Inferior object the thread belongs to.
1458 *** Changes in GDB 7.10
1460 * Support for process record-replay and reverse debugging on aarch64*-linux*
1461 targets has been added. GDB now supports recording of A64 instruction set
1462 including advance SIMD instructions.
1464 * Support for Sun's version of the "stabs" debug file format has been removed.
1466 * GDB now honors the content of the file /proc/PID/coredump_filter
1467 (PID is the process ID) on GNU/Linux systems. This file can be used
1468 to specify the types of memory mappings that will be included in a
1469 corefile. For more information, please refer to the manual page of
1470 "core(5)". GDB also has a new command: "set use-coredump-filter
1471 on|off". It allows to set whether GDB will read the content of the
1472 /proc/PID/coredump_filter file when generating a corefile.
1474 * The "info os" command on GNU/Linux can now display information on
1476 "info os cpus" Listing of all cpus/cores on the system
1478 * GDB has two new commands: "set serial parity odd|even|none" and
1479 "show serial parity". These allows to set or show parity for the
1482 * The "info source" command now displays the producer string if it was
1483 present in the debug info. This typically includes the compiler version
1484 and may include things like its command line arguments.
1486 * The "info dll", an alias of the "info sharedlibrary" command,
1487 is now available on all platforms.
1489 * Directory names supplied to the "set sysroot" commands may be
1490 prefixed with "target:" to tell GDB to access shared libraries from
1491 the target system, be it local or remote. This replaces the prefix
1492 "remote:". The default sysroot has been changed from "" to
1493 "target:". "remote:" is automatically converted to "target:" for
1494 backward compatibility.
1496 * The system root specified by "set sysroot" will be prepended to the
1497 filename of the main executable (if reported to GDB as absolute by
1498 the operating system) when starting processes remotely, and when
1499 attaching to already-running local or remote processes.
1501 * GDB now supports automatic location and retrieval of executable
1502 files from remote targets. Remote debugging can now be initiated
1503 using only a "target remote" or "target extended-remote" command
1504 (no "set sysroot" or "file" commands are required). See "New remote
1507 * The "dump" command now supports verilog hex format.
1509 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1511 * On GNU/Linux, GDB and gdbserver are now able to access executable
1512 and shared library files without a "set sysroot" command when
1513 attaching to processes running in different mount namespaces from
1514 the debugger. This makes it possible to attach to processes in
1515 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1516 See "New remote packets" below.
1518 * The "tui reg" command now provides completion for all of the
1519 available register groups, including target specific groups.
1521 * The HISTSIZE environment variable is no longer read when determining
1522 the size of GDB's command history. GDB now instead reads the dedicated
1523 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1524 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1529 ** Memory ports can now be unbuffered.
1533 ** gdb.Objfile objects have a new attribute "username",
1534 which is the name of the objfile as specified by the user,
1535 without, for example, resolving symlinks.
1536 ** You can now write frame unwinders in Python.
1537 ** gdb.Type objects have a new method "optimized_out",
1538 returning optimized out gdb.Value instance of this type.
1539 ** gdb.Value objects have new methods "reference_value" and
1540 "const_value" which return a reference to the value and a
1541 "const" version of the value respectively.
1545 maint print symbol-cache
1546 Print the contents of the symbol cache.
1548 maint print symbol-cache-statistics
1549 Print statistics of symbol cache usage.
1551 maint flush-symbol-cache
1552 Flush the contents of the symbol cache.
1556 Start branch trace recording using Branch Trace Store (BTS) format.
1559 Evaluate expression by using the compiler and print result.
1563 Explicit commands for enabling and disabling tui mode.
1566 set mpx bound on i386 and amd64
1567 Support for bound table investigation on Intel MPX enabled applications.
1571 Start branch trace recording using Intel Processor Trace format.
1574 Print information about branch tracing internals.
1576 maint btrace packet-history
1577 Print the raw branch tracing data.
1579 maint btrace clear-packet-history
1580 Discard the stored raw branch tracing data.
1583 Discard all branch tracing data. It will be fetched and processed
1584 anew by the next "record" command.
1589 Renamed from "set debug dwarf2-die".
1590 show debug dwarf-die
1591 Renamed from "show debug dwarf2-die".
1593 set debug dwarf-read
1594 Renamed from "set debug dwarf2-read".
1595 show debug dwarf-read
1596 Renamed from "show debug dwarf2-read".
1598 maint set dwarf always-disassemble
1599 Renamed from "maint set dwarf2 always-disassemble".
1600 maint show dwarf always-disassemble
1601 Renamed from "maint show dwarf2 always-disassemble".
1603 maint set dwarf max-cache-age
1604 Renamed from "maint set dwarf2 max-cache-age".
1605 maint show dwarf max-cache-age
1606 Renamed from "maint show dwarf2 max-cache-age".
1608 set debug dwarf-line
1609 show debug dwarf-line
1610 Control display of debugging info regarding DWARF line processing.
1613 show max-completions
1614 Set the maximum number of candidates to be considered during
1615 completion. The default value is 200. This limit allows GDB
1616 to avoid generating large completion lists, the computation of
1617 which can cause the debugger to become temporarily unresponsive.
1619 set history remove-duplicates
1620 show history remove-duplicates
1621 Control the removal of duplicate history entries.
1623 maint set symbol-cache-size
1624 maint show symbol-cache-size
1625 Control the size of the symbol cache.
1627 set|show record btrace bts buffer-size
1628 Set and show the size of the ring buffer used for branch tracing in
1630 The obtained size may differ from the requested size. Use "info
1631 record" to see the obtained buffer size.
1633 set debug linux-namespaces
1634 show debug linux-namespaces
1635 Control display of debugging info regarding Linux namespaces.
1637 set|show record btrace pt buffer-size
1638 Set and show the size of the ring buffer used for branch tracing in
1639 Intel Processor Trace format.
1640 The obtained size may differ from the requested size. Use "info
1641 record" to see the obtained buffer size.
1643 maint set|show btrace pt skip-pad
1644 Set and show whether PAD packets are skipped when computing the
1647 * The command 'thread apply all' can now support new option '-ascending'
1648 to call its specified command for all threads in ascending order.
1650 * Python/Guile scripting
1652 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1653 special section named `.debug_gdb_scripts'.
1655 * New remote packets
1657 qXfer:btrace-conf:read
1658 Return the branch trace configuration for the current thread.
1660 Qbtrace-conf:bts:size
1661 Set the requested ring buffer size for branch tracing in BTS format.
1664 Enable Intel Procesor Trace-based branch tracing for the current
1665 process. The remote stub reports support for this packet to GDB's
1668 Qbtrace-conf:pt:size
1669 Set the requested ring buffer size for branch tracing in Intel Processor
1673 Indicates a memory breakpoint instruction was executed, irrespective
1674 of whether it was GDB that planted the breakpoint or the breakpoint
1675 is hardcoded in the program. This is required for correct non-stop
1679 Indicates the target stopped for a hardware breakpoint. This is
1680 required for correct non-stop mode operation.
1683 Return information about files on the remote system.
1685 qXfer:exec-file:read
1686 Return the full absolute name of the file that was executed to
1687 create a process running on the remote system.
1690 Select the filesystem on which vFile: operations with filename
1691 arguments will operate. This is required for GDB to be able to
1692 access files on remote targets where the remote stub does not
1693 share a common filesystem with the inferior(s).
1696 Indicates that a fork system call was executed.
1699 Indicates that a vfork system call was executed.
1701 vforkdone stop reason
1702 Indicates that a vfork child of the specified process has executed
1703 an exec or exit, allowing the vfork parent to resume execution.
1705 fork-events and vfork-events features in qSupported
1706 The qSupported packet allows GDB to request support for fork and
1707 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1708 and the qSupported response can contain the corresponding
1709 'stubfeatures'. Set and show commands can be used to display
1710 whether these features are enabled.
1712 * Extended-remote fork events
1714 ** GDB now has support for fork events on extended-remote Linux
1715 targets. For targets with Linux kernels 2.5.60 and later, this
1716 enables follow-fork-mode and detach-on-fork for both fork and
1717 vfork, as well as fork and vfork catchpoints.
1719 * The info record command now shows the recording format and the
1720 branch tracing configuration for the current thread when using
1721 the btrace record target.
1722 For the BTS format, it shows the ring buffer size.
1724 * GDB now has support for DTrace USDT (Userland Static Defined
1725 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1727 * GDB now supports access to vector registers on S/390 GNU/Linux
1730 * Removed command line options
1732 -xdb HP-UX XDB compatibility mode.
1734 * Removed targets and native configurations
1736 HP/PA running HP-UX hppa*-*-hpux*
1737 Itanium running HP-UX ia64-*-hpux*
1739 * New configure options
1742 This configure option allows the user to build GDB with support for
1743 Intel Processor Trace (default: auto). This requires libipt.
1745 --with-libipt-prefix=PATH
1746 Specify the path to the version of libipt that GDB should use.
1747 $PATH/include should contain the intel-pt.h header and
1748 $PATH/lib should contain the libipt.so library.
1750 *** Changes in GDB 7.9.1
1754 ** Xmethods can now specify a result type.
1756 *** Changes in GDB 7.9
1758 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1762 ** You can now access frame registers from Python scripts.
1763 ** New attribute 'producer' for gdb.Symtab objects.
1764 ** gdb.Objfile objects have a new attribute "progspace",
1765 which is the gdb.Progspace object of the containing program space.
1766 ** gdb.Objfile objects have a new attribute "owner".
1767 ** gdb.Objfile objects have a new attribute "build_id",
1768 which is the build ID generated when the file was built.
1769 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1770 ** A new event "gdb.clear_objfiles" has been added, triggered when
1771 selecting a new file to debug.
1772 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1773 ** New function gdb.lookup_objfile.
1775 New events which are triggered when GDB modifies the state of the
1778 ** gdb.events.inferior_call_pre: Function call is about to be made.
1779 ** gdb.events.inferior_call_post: Function call has just been made.
1780 ** gdb.events.memory_changed: A memory location has been altered.
1781 ** gdb.events.register_changed: A register has been altered.
1783 * New Python-based convenience functions:
1785 ** $_caller_is(name [, number_of_frames])
1786 ** $_caller_matches(regexp [, number_of_frames])
1787 ** $_any_caller_is(name [, number_of_frames])
1788 ** $_any_caller_matches(regexp [, number_of_frames])
1790 * GDB now supports the compilation and injection of source code into
1791 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1792 to compile the source code to object code, and if successful, inject
1793 and execute that code within the current context of the inferior.
1794 Currently the C language is supported. The commands used to
1795 interface with this new feature are:
1797 compile code [-raw|-r] [--] [source code]
1798 compile file [-raw|-r] filename
1802 demangle [-l language] [--] name
1803 Demangle "name" in the specified language, or the current language
1804 if elided. This command is renamed from the "maint demangle" command.
1805 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1806 as "maint demangler-warning".
1808 queue-signal signal-name-or-number
1809 Queue a signal to be delivered to the thread when it is resumed.
1811 add-auto-load-scripts-directory directory
1812 Add entries to the list of directories from which to load auto-loaded
1815 maint print user-registers
1816 List all currently available "user" registers.
1818 compile code [-r|-raw] [--] [source code]
1819 Compile, inject, and execute in the inferior the executable object
1820 code produced by compiling the provided source code.
1822 compile file [-r|-raw] filename
1823 Compile and inject into the inferior the executable object code
1824 produced by compiling the source code stored in the filename
1827 * On resume, GDB now always passes the signal the program had stopped
1828 for to the thread the signal was sent to, even if the user changed
1829 threads before resuming. Previously GDB would often (but not
1830 always) deliver the signal to the thread that happens to be current
1833 * Conversely, the "signal" command now consistently delivers the
1834 requested signal to the current thread. GDB now asks for
1835 confirmation if the program had stopped for a signal and the user
1836 switched threads meanwhile.
1838 * "breakpoint always-inserted" modes "off" and "auto" merged.
1840 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1841 won't remove breakpoints from the target until all threads stop,
1842 even in non-stop mode. The "auto" mode has been removed, and "off"
1843 is now the default mode.
1847 set debug symbol-lookup
1848 show debug symbol-lookup
1849 Control display of debugging info regarding symbol lookup.
1853 ** The -list-thread-groups command outputs an exit-code field for
1854 inferiors that have exited.
1858 MIPS SDE mips*-sde*-elf*
1862 Support for these obsolete configurations has been removed.
1864 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1865 SGI Irix-5.x mips-*-irix5*
1866 SGI Irix-6.x mips-*-irix6*
1867 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1868 VAX running Ultrix vax-*-ultrix*
1870 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1871 and "assf"), have been removed. Use the "sharedlibrary" command, or
1872 its alias "share", instead.
1874 *** Changes in GDB 7.8
1876 * New command line options
1879 This is an alias for the --data-directory option.
1881 * GDB supports printing and modifying of variable length automatic arrays
1882 as specified in ISO C99.
1884 * The ARM simulator now supports instruction level tracing
1885 with or without disassembly.
1889 GDB now has support for scripting using Guile. Whether this is
1890 available is determined at configure time.
1891 Guile version 2.0 or greater is required.
1892 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1894 * New commands (for set/show, see "New options" below)
1898 Invoke CODE by passing it to the Guile interpreter.
1902 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1904 info auto-load guile-scripts [regexp]
1905 Print the list of automatically loaded Guile scripts.
1907 * The source command is now capable of sourcing Guile scripts.
1908 This feature is dependent on the debugger being built with Guile support.
1912 set print symbol-loading (off|brief|full)
1913 show print symbol-loading
1914 Control whether to print informational messages when loading symbol
1915 information for a file. The default is "full", but when debugging
1916 programs with large numbers of shared libraries the amount of output
1917 becomes less useful.
1919 set guile print-stack (none|message|full)
1920 show guile print-stack
1921 Show a stack trace when an error is encountered in a Guile script.
1923 set auto-load guile-scripts (on|off)
1924 show auto-load guile-scripts
1925 Control auto-loading of Guile script files.
1927 maint ada set ignore-descriptive-types (on|off)
1928 maint ada show ignore-descriptive-types
1929 Control whether the debugger should ignore descriptive types in Ada
1930 programs. The default is not to ignore the descriptive types. See
1931 the user manual for more details on descriptive types and the intended
1932 usage of this option.
1934 set auto-connect-native-target
1936 Control whether GDB is allowed to automatically connect to the
1937 native target for the run, attach, etc. commands when not connected
1938 to any target yet. See also "target native" below.
1940 set record btrace replay-memory-access (read-only|read-write)
1941 show record btrace replay-memory-access
1942 Control what memory accesses are allowed during replay.
1944 maint set target-async (on|off)
1945 maint show target-async
1946 This controls whether GDB targets operate in synchronous or
1947 asynchronous mode. Normally the default is asynchronous, if it is
1948 available; but this can be changed to more easily debug problems
1949 occurring only in synchronous mode.
1951 set mi-async (on|off)
1953 Control whether MI asynchronous mode is preferred. This supersedes
1954 "set target-async" of previous GDB versions.
1956 * "set target-async" is deprecated as a CLI option and is now an alias
1957 for "set mi-async" (only puts MI into async mode).
1959 * Background execution commands (e.g., "c&", "s&", etc.) are now
1960 possible ``out of the box'' if the target supports them. Previously
1961 the user would need to explicitly enable the possibility with the
1962 "set target-async on" command.
1964 * New features in the GDB remote stub, GDBserver
1966 ** New option --debug-format=option1[,option2,...] allows one to add
1967 additional text to each output. At present only timestamps
1968 are supported: --debug-format=timestamps.
1969 Timestamps can also be turned on with the
1970 "monitor set debug-format timestamps" command from GDB.
1972 * The 'record instruction-history' command now starts counting instructions
1973 at one. This also affects the instruction ranges reported by the
1974 'record function-call-history' command when given the /i modifier.
1976 * The command 'record function-call-history' supports a new modifier '/c' to
1977 indent the function names based on their call stack depth.
1978 The fields for the '/i' and '/l' modifier have been reordered.
1979 The source line range is now prefixed with 'at'.
1980 The instruction range is now prefixed with 'inst'.
1981 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1982 "record instruction-history" and "list" commands.
1984 * The ranges given as arguments to the 'record function-call-history' and
1985 'record instruction-history' commands are now inclusive.
1987 * The btrace record target now supports the 'record goto' command.
1988 For locations inside the execution trace, the back trace is computed
1989 based on the information stored in the execution trace.
1991 * The btrace record target supports limited reverse execution and replay.
1992 The target does not record data and therefore does not allow reading
1993 memory or registers.
1995 * The "catch syscall" command now works on s390*-linux* targets.
1997 * The "compare-sections" command is no longer specific to target
1998 remote. It now works with all targets.
2000 * All native targets are now consistently called "native".
2001 Consequently, the "target child", "target GNU", "target djgpp",
2002 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2003 commands have been replaced with "target native". The QNX/NTO port
2004 leaves the "procfs" target in place and adds a "native" target for
2005 consistency with other ports. The impact on users should be minimal
2006 as these commands previously either throwed an error, or were
2007 no-ops. The target's name is visible in the output of the following
2008 commands: "help target", "info target", "info files", "maint print
2011 * The "target native" command now connects to the native target. This
2012 can be used to launch native programs even when "set
2013 auto-connect-native-target" is set to off.
2015 * GDB now supports access to Intel MPX registers on GNU/Linux.
2017 * Support for Intel AVX-512 registers on GNU/Linux.
2018 Support displaying and modifying Intel AVX-512 registers
2019 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2021 * New remote packets
2023 qXfer:btrace:read's annex
2024 The qXfer:btrace:read packet supports a new annex 'delta' to read
2025 branch trace incrementally.
2029 ** Valid Python operations on gdb.Value objects representing
2030 structs/classes invoke the corresponding overloaded operators if
2032 ** New `Xmethods' feature in the Python API. Xmethods are
2033 additional methods or replacements for existing methods of a C++
2034 class. This feature is useful for those cases where a method
2035 defined in C++ source code could be inlined or optimized out by
2036 the compiler, making it unavailable to GDB.
2039 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2041 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2042 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2043 its alias "share", instead.
2045 * The commands "set remotebaud" and "show remotebaud" are no longer
2046 supported. Use "set serial baud" and "show serial baud" (respectively)
2051 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2052 target-async". The latter is left as a deprecated alias of the
2053 former for backward compatibility. If the target supports it,
2054 CLI background execution commands are now always possible by
2055 default, independently of whether the frontend stated a
2056 preference for asynchronous execution with "-gdb-set mi-async".
2057 Previously "-gdb-set target-async off" affected both MI execution
2058 commands and CLI execution commands.
2060 *** Changes in GDB 7.7
2062 * Improved support for process record-replay and reverse debugging on
2063 arm*-linux* targets. Support for thumb32 and syscall instruction
2064 recording has been added.
2066 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2068 * GDB now supports Fission DWP file format version 2.
2069 http://gcc.gnu.org/wiki/DebugFission
2071 * New convenience function "$_isvoid", to check whether an expression
2072 is void. A void expression is an expression where the type of the
2073 result is "void". For example, some convenience variables may be
2074 "void" when evaluated (e.g., "$_exitcode" before the execution of
2075 the program being debugged; or an undefined convenience variable).
2076 Another example, when calling a function whose return type is
2079 * The "maintenance print objfiles" command now takes an optional regexp.
2081 * The "catch syscall" command now works on arm*-linux* targets.
2083 * GDB now consistently shows "<not saved>" when printing values of
2084 registers the debug info indicates have not been saved in the frame
2085 and there's nowhere to retrieve them from
2086 (callee-saved/call-clobbered registers):
2091 (gdb) info registers rax
2094 Before, the former would print "<optimized out>", and the latter
2095 "*value not available*".
2097 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2102 ** Frame filters and frame decorators have been added.
2103 ** Temporary breakpoints are now supported.
2104 ** Line tables representation has been added.
2105 ** New attribute 'parent_type' for gdb.Field objects.
2106 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2107 ** New attribute 'name' for gdb.Type objects.
2111 Nios II ELF nios2*-*-elf
2112 Nios II GNU/Linux nios2*-*-linux
2113 Texas Instruments MSP430 msp430*-*-elf
2115 * Removed native configurations
2117 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2118 been removed. ELF variants of these configurations are kept supported.
2120 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2121 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2122 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2123 i[34567]86-*-openbsd3.[0-3]
2124 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2125 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2126 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2130 Like "catch throw", but catches a re-thrown exception.
2131 maint check-psymtabs
2132 Renamed from old "maint check-symtabs".
2134 Perform consistency checks on symtabs.
2135 maint expand-symtabs
2136 Expand symtabs matching an optional regexp.
2139 Display the details of GDB configure-time options.
2141 maint set|show per-command
2142 maint set|show per-command space
2143 maint set|show per-command time
2144 maint set|show per-command symtab
2145 Enable display of per-command gdb resource usage.
2147 remove-symbol-file FILENAME
2148 remove-symbol-file -a ADDRESS
2149 Remove a symbol file added via add-symbol-file. The file to remove
2150 can be identified by its filename or by an address that lies within
2151 the boundaries of this symbol file in memory.
2154 info exceptions REGEXP
2155 Display the list of Ada exceptions defined in the program being
2156 debugged. If provided, only the exceptions whose names match REGEXP
2161 set debug symfile off|on
2163 Control display of debugging info regarding reading symbol files and
2164 symbol tables within those files
2166 set print raw frame-arguments
2167 show print raw frame-arguments
2168 Set/show whether to print frame arguments in raw mode,
2169 disregarding any defined pretty-printers.
2171 set remote trace-status-packet
2172 show remote trace-status-packet
2173 Set/show the use of remote protocol qTStatus packet.
2177 Control display of debugging messages related to Nios II targets.
2181 Control whether target-assisted range stepping is enabled.
2183 set startup-with-shell
2184 show startup-with-shell
2185 Specifies whether Unix child processes are started via a shell or
2190 Use the target memory cache for accesses to the code segment. This
2191 improves performance of remote debugging (particularly disassembly).
2193 * You can now use a literal value 'unlimited' for options that
2194 interpret 0 or -1 as meaning "unlimited". E.g., "set
2195 trace-buffer-size unlimited" is now an alias for "set
2196 trace-buffer-size -1" and "set height unlimited" is now an alias for
2199 * The "set debug symtab-create" debugging option of GDB has been changed to
2200 accept a verbosity level. 0 means "off", 1 provides basic debugging
2201 output, and values of 2 or greater provides more verbose output.
2203 * New command-line options
2205 Display the details of GDB configure-time options.
2207 * The command 'tsave' can now support new option '-ctf' to save trace
2208 buffer in Common Trace Format.
2210 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2213 * GDB now implements the the C++ 'typeid' operator.
2215 * The new convenience variable $_exception holds the exception being
2216 thrown or caught at an exception-related catchpoint.
2218 * The exception-related catchpoints, like "catch throw", now accept a
2219 regular expression which can be used to filter exceptions by type.
2221 * The new convenience variable $_exitsignal is automatically set to
2222 the terminating signal number when the program being debugged dies
2223 due to an uncaught signal.
2227 ** All MI commands now accept an optional "--language" option.
2228 Support for this feature can be verified by using the "-list-features"
2229 command, which should contain "language-option".
2231 ** The new command -info-gdb-mi-command allows the user to determine
2232 whether a GDB/MI command is supported or not.
2234 ** The "^error" result record returned when trying to execute an undefined
2235 GDB/MI command now provides a variable named "code" whose content is the
2236 "undefined-command" error code. Support for this feature can be verified
2237 by using the "-list-features" command, which should contain
2238 "undefined-command-error-code".
2240 ** The -trace-save MI command can optionally save trace buffer in Common
2243 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2245 ** The command -data-list-register-values now accepts an optional
2246 "--skip-unavailable" option. When used, only the available registers
2249 ** The new command -trace-frame-collected dumps collected variables,
2250 computed expressions, tvars, memory and registers in a traceframe.
2252 ** The commands -stack-list-locals, -stack-list-arguments and
2253 -stack-list-variables now accept an option "--skip-unavailable".
2254 When used, only the available locals or arguments are displayed.
2256 ** The -exec-run command now accepts an optional "--start" option.
2257 When used, the command follows the same semantics as the "start"
2258 command, stopping the program's execution at the start of its
2259 main subprogram. Support for this feature can be verified using
2260 the "-list-features" command, which should contain
2261 "exec-run-start-option".
2263 ** The new commands -catch-assert and -catch-exceptions insert
2264 catchpoints stopping the program when Ada exceptions are raised.
2266 ** The new command -info-ada-exceptions provides the equivalent of
2267 the new "info exceptions" command.
2269 * New system-wide configuration scripts
2270 A GDB installation now provides scripts suitable for use as system-wide
2271 configuration scripts for the following systems:
2275 * GDB now supports target-assigned range stepping with remote targets.
2276 This improves the performance of stepping source lines by reducing
2277 the number of control packets from/to GDB. See "New remote packets"
2280 * GDB now understands the element 'tvar' in the XML traceframe info.
2281 It has the id of the collected trace state variables.
2283 * On S/390 targets that provide the transactional-execution feature,
2284 the program interruption transaction diagnostic block (TDB) is now
2285 represented as a number of additional "registers" in GDB.
2287 * New remote packets
2291 The vCont packet supports a new 'r' action, that tells the remote
2292 stub to step through an address range itself, without GDB
2293 involvemement at each single-step.
2295 qXfer:libraries-svr4:read's annex
2296 The previously unused annex of the qXfer:libraries-svr4:read packet
2297 is now used to support passing an argument list. The remote stub
2298 reports support for this argument list to GDB's qSupported query.
2299 The defined arguments are "start" and "prev", used to reduce work
2300 necessary for library list updating, resulting in significant
2303 * New features in the GDB remote stub, GDBserver
2305 ** GDBserver now supports target-assisted range stepping. Currently
2306 enabled on x86/x86_64 GNU/Linux targets.
2308 ** GDBserver now adds element 'tvar' in the XML in the reply to
2309 'qXfer:traceframe-info:read'. It has the id of the collected
2310 trace state variables.
2312 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2315 * New 'z' formatter for printing and examining memory, this displays the
2316 value as hexadecimal zero padded on the left to the size of the type.
2318 * GDB can now use Windows x64 unwinding data.
2320 * The "set remotebaud" command has been replaced by "set serial baud".
2321 Similarly, "show remotebaud" has been replaced by "show serial baud".
2322 The "set remotebaud" and "show remotebaud" commands are still available
2323 to provide backward compatibility with older versions of GDB.
2325 *** Changes in GDB 7.6
2327 * Target record has been renamed to record-full.
2328 Record/replay is now enabled with the "record full" command.
2329 This also affects settings that are associated with full record/replay
2330 that have been moved from "set/show record" to "set/show record full":
2332 set|show record full insn-number-max
2333 set|show record full stop-at-limit
2334 set|show record full memory-query
2336 * A new record target "record-btrace" has been added. The new target
2337 uses hardware support to record the control-flow of a process. It
2338 does not support replaying the execution, but it implements the
2339 below new commands for investigating the recorded execution log.
2340 This new recording method can be enabled using:
2344 The "record-btrace" target is only available on Intel Atom processors
2345 and requires a Linux kernel 2.6.32 or later.
2347 * Two new commands have been added for record/replay to give information
2348 about the recorded execution without having to replay the execution.
2349 The commands are only supported by "record btrace".
2351 record instruction-history prints the execution history at
2352 instruction granularity
2354 record function-call-history prints the execution history at
2355 function granularity
2357 * New native configurations
2359 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2360 FreeBSD/powerpc powerpc*-*-freebsd
2361 x86_64/Cygwin x86_64-*-cygwin*
2362 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2366 ARM AArch64 aarch64*-*-elf
2367 ARM AArch64 GNU/Linux aarch64*-*-linux
2368 Lynx 178 PowerPC powerpc-*-lynx*178
2369 x86_64/Cygwin x86_64-*-cygwin*
2370 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2372 * If the configured location of system.gdbinit file (as given by the
2373 --with-system-gdbinit option at configure time) is in the
2374 data-directory (as specified by --with-gdb-datadir at configure
2375 time) or in one of its subdirectories, then GDB will look for the
2376 system-wide init file in the directory specified by the
2377 --data-directory command-line option.
2379 * New command line options:
2381 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2382 other initialization files, unlike -nx which disables all of them.
2384 * Removed command line options
2386 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2389 * The 'ptype' and 'whatis' commands now accept an argument to control
2392 * 'info proc' now works on some core files.
2396 ** Vectors can be created with gdb.Type.vector.
2398 ** Python's atexit.register now works in GDB.
2400 ** Types can be pretty-printed via a Python API.
2402 ** Python 3 is now supported (in addition to Python 2.4 or later)
2404 ** New class gdb.Architecture exposes GDB's internal representation
2405 of architecture in the Python API.
2407 ** New method Frame.architecture returns the gdb.Architecture object
2408 corresponding to the frame's architecture.
2410 * New Python-based convenience functions:
2412 ** $_memeq(buf1, buf2, length)
2413 ** $_streq(str1, str2)
2415 ** $_regex(str, regex)
2417 * The 'cd' command now defaults to using '~' (the home directory) if not
2420 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2421 default for GCC since November 2000.
2423 * The command 'forward-search' can now be abbreviated as 'fo'.
2425 * The command 'info tracepoints' can now display 'installed on target'
2426 or 'not installed on target' for each non-pending location of tracepoint.
2428 * New configure options
2430 --enable-libmcheck/--disable-libmcheck
2431 By default, development versions are built with -lmcheck on hosts
2432 that support it, in order to help track memory corruption issues.
2433 Release versions, on the other hand, are built without -lmcheck
2434 by default. The --enable-libmcheck/--disable-libmcheck configure
2435 options allow the user to override that default.
2436 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2437 This configure option allows the user to build GDB with
2438 libbabeltrace using which GDB can read Common Trace Format data.
2440 * New commands (for set/show, see "New options" below)
2443 Catch signals. This is similar to "handle", but allows commands and
2444 conditions to be attached.
2447 List the BFDs known to GDB.
2449 python-interactive [command]
2451 Start a Python interactive prompt, or evaluate the optional command
2452 and print the result of expressions.
2455 "py" is a new alias for "python".
2457 enable type-printer [name]...
2458 disable type-printer [name]...
2459 Enable or disable type printers.
2463 ** For the Renesas Super-H architecture, the "regs" command has been removed
2464 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2469 set print type methods (on|off)
2470 show print type methods
2471 Control whether method declarations are displayed by "ptype".
2472 The default is to show them.
2474 set print type typedefs (on|off)
2475 show print type typedefs
2476 Control whether typedef definitions are displayed by "ptype".
2477 The default is to show them.
2479 set filename-display basename|relative|absolute
2480 show filename-display
2481 Control the way in which filenames is displayed.
2482 The default is "relative", which preserves previous behavior.
2484 set trace-buffer-size
2485 show trace-buffer-size
2486 Request target to change the size of trace buffer.
2488 set remote trace-buffer-size-packet auto|on|off
2489 show remote trace-buffer-size-packet
2490 Control the use of the remote protocol `QTBuffer:size' packet.
2494 Control display of debugging messages related to ARM AArch64.
2497 set debug coff-pe-read
2498 show debug coff-pe-read
2499 Control display of debugging messages related to reading of COFF/PE
2504 Control display of debugging messages related to Mach-O symbols
2507 set debug notification
2508 show debug notification
2509 Control display of debugging info for async remote notification.
2513 ** Command parameter changes are now notified using new async record
2514 "=cmd-param-changed".
2515 ** Trace frame changes caused by command "tfind" are now notified using
2516 new async record "=traceframe-changed".
2517 ** The creation, deletion and modification of trace state variables
2518 are now notified using new async records "=tsv-created",
2519 "=tsv-deleted" and "=tsv-modified".
2520 ** The start and stop of process record are now notified using new
2521 async record "=record-started" and "=record-stopped".
2522 ** Memory changes are now notified using new async record
2524 ** The data-disassemble command response will include a "fullname" field
2525 containing the absolute file name when source has been requested.
2526 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2527 command, to allow pattern filling of memory areas.
2528 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2529 library load/unload events.
2530 ** The response to breakpoint commands and breakpoint async records
2531 includes an "installed" field containing a boolean state about each
2532 non-pending tracepoint location is whether installed on target or not.
2533 ** Output of the "-trace-status" command includes a "trace-file" field
2534 containing the name of the trace file being examined. This field is
2535 optional, and only present when examining a trace file.
2536 ** The "fullname" field is now always present along with the "file" field,
2537 even if the file cannot be found by GDB.
2539 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2540 You must have the LZMA library available when configuring GDB for this
2541 feature to be enabled. For more information, see:
2542 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2544 * New remote packets
2547 Set the size of trace buffer. The remote stub reports support for this
2548 packet to gdb's qSupported query.
2551 Enable Branch Trace Store (BTS)-based branch tracing for the current
2552 thread. The remote stub reports support for this packet to gdb's
2556 Disable branch tracing for the current thread. The remote stub reports
2557 support for this packet to gdb's qSupported query.
2560 Read the traced branches for the current thread. The remote stub
2561 reports support for this packet to gdb's qSupported query.
2563 *** Changes in GDB 7.5
2565 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2566 for more x32 ABI info.
2568 * GDB now supports access to MIPS DSP registers on Linux targets.
2570 * GDB now supports debugging microMIPS binaries.
2572 * The "info os" command on GNU/Linux can now display information on
2573 several new classes of objects managed by the operating system:
2574 "info os procgroups" lists process groups
2575 "info os files" lists file descriptors
2576 "info os sockets" lists internet-domain sockets
2577 "info os shm" lists shared-memory regions
2578 "info os semaphores" lists semaphores
2579 "info os msg" lists message queues
2580 "info os modules" lists loaded kernel modules
2582 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2583 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2584 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2585 options and inspect the probe arguments using the new $_probe_arg family
2586 of convenience variables. You can obtain more information about SystemTap
2587 in <http://sourceware.org/systemtap/>.
2589 * GDB now supports reversible debugging on ARM, it allows you to
2590 debug basic ARM and THUMB instructions, and provides
2591 record/replay support.
2593 * The option "symbol-reloading" has been deleted as it is no longer used.
2597 ** GDB commands implemented in Python can now be put in command class
2600 ** The "maint set python print-stack on|off" is now deleted.
2602 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2603 apply "flag enum"-style pretty-printing to any enum.
2605 ** gdb.lookup_symbol can now work when there is no current frame.
2607 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2608 the source at which the symbol was defined.
2610 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2611 method 'value'. The former indicates whether the symbol needs a
2612 frame in order to compute its value, and the latter computes the
2615 ** A new method 'referenced_value' on gdb.Value objects which can
2616 dereference pointer as well as C++ reference values.
2618 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2619 which return the global and static blocks (as gdb.Block objects),
2620 of the underlying symbol table, respectively.
2622 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2623 object associated with a PC value.
2625 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2626 of the address range occupied by code for the current source line.
2628 * Go language support.
2629 GDB now supports debugging programs written in the Go programming
2632 * GDBserver now supports stdio connections.
2633 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2635 * The binary "gdbtui" can no longer be built or installed.
2636 Use "gdb -tui" instead.
2638 * GDB will now print "flag" enums specially. A flag enum is one where
2639 all the enumerator values have no bits in common when pairwise
2640 "and"ed. When printing a value whose type is a flag enum, GDB will
2641 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2642 (gdb) print (enum E) 3
2645 * The filename part of a linespec will now match trailing components
2646 of a source file name. For example, "break gcc/expr.c:1000" will
2647 now set a breakpoint in build/gcc/expr.c, but not
2648 build/libcpp/expr.c.
2650 * The "info proc" and "generate-core-file" commands will now also
2651 work on remote targets connected to GDBserver on Linux.
2653 * The command "info catch" has been removed. It has been disabled
2654 since December 2007.
2656 * The "catch exception" and "catch assert" commands now accept
2657 a condition at the end of the command, much like the "break"
2658 command does. For instance:
2660 (gdb) catch exception Constraint_Error if Barrier = True
2662 Previously, it was possible to add a condition to such catchpoints,
2663 but it had to be done as a second step, after the catchpoint had been
2664 created, using the "condition" command.
2666 * The "info static-tracepoint-marker" command will now also work on
2667 native Linux targets with in-process agent.
2669 * GDB can now set breakpoints on inlined functions.
2671 * The .gdb_index section has been updated to include symbols for
2672 inlined functions. GDB will ignore older .gdb_index sections by
2673 default, which could cause symbol files to be loaded more slowly
2674 until their .gdb_index sections can be recreated. The new command
2675 "set use-deprecated-index-sections on" will cause GDB to use any older
2676 .gdb_index sections it finds. This will restore performance, but the
2677 ability to set breakpoints on inlined functions will be lost in symbol
2678 files with older .gdb_index sections.
2680 The .gdb_index section has also been updated to record more information
2681 about each symbol. This speeds up the "info variables", "info functions"
2682 and "info types" commands when used with programs having the .gdb_index
2683 section, as well as speeding up debugging with shared libraries using
2684 the .gdb_index section.
2686 * Ada support for GDB/MI Variable Objects has been added.
2688 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2693 ** New command -info-os is the MI equivalent of "info os".
2695 ** Output logs ("set logging" and related) now include MI output.
2699 ** "set use-deprecated-index-sections on|off"
2700 "show use-deprecated-index-sections on|off"
2701 Controls the use of deprecated .gdb_index sections.
2703 ** "catch load" and "catch unload" can be used to stop when a shared
2704 library is loaded or unloaded, respectively.
2706 ** "enable count" can be used to auto-disable a breakpoint after
2709 ** "info vtbl" can be used to show the virtual method tables for
2710 C++ and Java objects.
2712 ** "explore" and its sub commands "explore value" and "explore type"
2713 can be used to recursively explore values and types of
2714 expressions. These commands are available only if GDB is
2715 configured with '--with-python'.
2717 ** "info auto-load" shows status of all kinds of auto-loaded files,
2718 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2719 sequences of commands files, "info auto-load python-scripts"
2720 shows status of auto-loading Python script files,
2721 "info auto-load local-gdbinit" shows status of loading init file
2722 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2723 status of inferior specific thread debugging shared library loading.
2725 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2726 and "show auto-load-scripts" commands have been deprecated, use their
2727 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2728 and "show auto-load python-scripts" counterparts instead.
2730 ** "dprintf location,format,args..." creates a dynamic printf, which
2731 is basically a breakpoint that does a printf and immediately
2732 resumes your program's execution, so it is like a printf that you
2733 can insert dynamically at runtime instead of at compiletime.
2735 ** "set print symbol"
2737 Controls whether GDB attempts to display the symbol, if any,
2738 corresponding to addresses it prints. This defaults to "on", but
2739 you can set it to "off" to restore GDB's previous behavior.
2741 * Deprecated commands
2743 ** For the Renesas Super-H architecture, the "regs" command has been
2744 deprecated, and "info all-registers" should be used instead.
2748 Renesas RL78 rl78-*-elf
2749 HP OpenVMS ia64 ia64-hp-openvms*
2751 * GDBserver supports evaluation of breakpoint conditions. When
2752 support is advertised by GDBserver, GDB may be told to send the
2753 breakpoint conditions in bytecode form to GDBserver. GDBserver
2754 will only report the breakpoint trigger to GDB when its condition
2759 set mips compression
2760 show mips compression
2761 Select the compressed ISA encoding used in functions that have no symbol
2762 information available. The encoding can be set to either of:
2765 and is updated automatically from ELF file flags if available.
2767 set breakpoint condition-evaluation
2768 show breakpoint condition-evaluation
2769 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2770 GDBserver ("target"). Default option "auto" chooses the most efficient
2772 This option can improve debugger efficiency depending on the speed of the
2776 Disable auto-loading globally.
2779 Show auto-loading setting of all kinds of auto-loaded files.
2781 set auto-load gdb-scripts on|off
2782 show auto-load gdb-scripts
2783 Control auto-loading of GDB canned sequences of commands files.
2785 set auto-load python-scripts on|off
2786 show auto-load python-scripts
2787 Control auto-loading of Python script files.
2789 set auto-load local-gdbinit on|off
2790 show auto-load local-gdbinit
2791 Control loading of init file (.gdbinit) from current directory.
2793 set auto-load libthread-db on|off
2794 show auto-load libthread-db
2795 Control auto-loading of inferior specific thread debugging shared library.
2797 set auto-load scripts-directory <dir1>[:<dir2>...]
2798 show auto-load scripts-directory
2799 Set a list of directories from which to load auto-loaded scripts.
2800 Automatically loaded Python scripts and GDB scripts are located in one
2801 of the directories listed by this option.
2802 The delimiter (':' above) may differ according to the host platform.
2804 set auto-load safe-path <dir1>[:<dir2>...]
2805 show auto-load safe-path
2806 Set a list of directories from which it is safe to auto-load files.
2807 The delimiter (':' above) may differ according to the host platform.
2809 set debug auto-load on|off
2810 show debug auto-load
2811 Control display of debugging info for auto-loading the files above.
2813 set dprintf-style gdb|call|agent
2815 Control the way in which a dynamic printf is performed; "gdb"
2816 requests a GDB printf command, while "call" causes dprintf to call a
2817 function in the inferior. "agent" requests that the target agent
2818 (such as GDBserver) do the printing.
2820 set dprintf-function <expr>
2821 show dprintf-function
2822 set dprintf-channel <expr>
2823 show dprintf-channel
2824 Set the function and optional first argument to the call when using
2825 the "call" style of dynamic printf.
2827 set disconnected-dprintf on|off
2828 show disconnected-dprintf
2829 Control whether agent-style dynamic printfs continue to be in effect
2830 after GDB disconnects.
2832 * New configure options
2834 --with-auto-load-dir
2835 Configure default value for the 'set auto-load scripts-directory'
2836 setting above. It defaults to '$debugdir:$datadir/auto-load',
2837 $debugdir representing global debugging info directories (available
2838 via 'show debug-file-directory') and $datadir representing GDB's data
2839 directory (available via 'show data-directory').
2841 --with-auto-load-safe-path
2842 Configure default value for the 'set auto-load safe-path' setting
2843 above. It defaults to the --with-auto-load-dir setting.
2845 --without-auto-load-safe-path
2846 Set 'set auto-load safe-path' to '/', effectively disabling this
2849 * New remote packets
2851 z0/z1 conditional breakpoints extension
2853 The z0/z1 breakpoint insertion packets have been extended to carry
2854 a list of conditional expressions over to the remote stub depending on the
2855 condition evaluation mode. The use of this extension can be controlled
2856 via the "set remote conditional-breakpoints-packet" command.
2860 Specify the signals which the remote stub may pass to the debugged
2861 program without GDB involvement.
2863 * New command line options
2865 --init-command=FILE, -ix Like --command, -x but execute it
2866 before loading inferior.
2867 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2868 execute it before loading inferior.
2870 *** Changes in GDB 7.4
2872 * GDB now handles ambiguous linespecs more consistently; the existing
2873 FILE:LINE support has been expanded to other types of linespecs. A
2874 breakpoint will now be set on all matching locations in all
2875 inferiors, and locations will be added or removed according to
2878 * GDB now allows you to skip uninteresting functions and files when
2879 stepping with the "skip function" and "skip file" commands.
2881 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2882 and "show remote hardware-watchpoint-length-limit". These allows to
2883 set or show the maximum length limit (in bytes) of a remote
2884 target hardware watchpoint.
2886 This allows e.g. to use "unlimited" hardware watchpoints with the
2887 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2888 watchpoints are slower than real hardware watchpoints but are
2889 significantly faster than gdb software watchpoints.
2893 ** The register_pretty_printer function in module gdb.printing now takes
2894 an optional `replace' argument. If True, the new printer replaces any
2897 ** The "maint set python print-stack on|off" command has been
2898 deprecated and will be deleted in GDB 7.5.
2899 A new command: "set python print-stack none|full|message" has
2900 replaced it. Additionally, the default for "print-stack" is
2901 now "message", which just prints the error message without
2904 ** A prompt substitution hook (prompt_hook) is now available to the
2907 ** A new Python module, gdb.prompt has been added to the GDB Python
2908 modules library. This module provides functionality for
2909 escape sequences in prompts (used by set/show
2910 extended-prompt). These escape sequences are replaced by their
2911 corresponding value.
2913 ** Python commands and convenience-functions located in
2914 'data-directory'/python/gdb/command and
2915 'data-directory'/python/gdb/function are now automatically loaded
2918 ** Blocks now provide four new attributes. global_block and
2919 static_block will return the global and static blocks
2920 respectively. is_static and is_global are boolean attributes
2921 that indicate if the block is one of those two types.
2923 ** Symbols now provide the "type" attribute, the type of the symbol.
2925 ** The "gdb.breakpoint" function has been deprecated in favor of
2928 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2929 of a function. This class is based on the "finish" command
2930 available in the CLI.
2932 ** Type objects for struct and union types now allow access to
2933 the fields using standard Python dictionary (mapping) methods.
2934 For example, "some_type['myfield']" now works, as does
2935 "some_type.items()".
2937 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2940 ** A new function, "deep_items" has been added to the gdb.types
2941 module in the GDB Python modules library. This function returns
2942 an iterator over the fields of a struct or union type. Unlike
2943 the standard Python "iteritems" method, it will recursively traverse
2944 any anonymous fields.
2948 ** "*stopped" events can report several new "reason"s, such as
2951 ** Breakpoint changes are now notified using new async records, like
2952 "=breakpoint-modified".
2954 ** New command -ada-task-info.
2956 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2957 $sdir specifies the default system locations of shared libraries.
2958 $pdir specifies the directory where the libpthread used by the application
2961 GDB no longer looks in $sdir and $pdir after it has searched the directories
2962 mentioned in libthread-db-search-path. If you want to search those
2963 directories, they must be specified in libthread-db-search-path.
2964 The default value of libthread-db-search-path on GNU/Linux and Solaris
2965 systems is now "$sdir:$pdir".
2967 $pdir is not supported by gdbserver, it is currently ignored.
2968 $sdir is supported by gdbserver.
2970 * New configure option --with-iconv-bin.
2971 When using the internationalization support like the one in the GNU C
2972 library, GDB will invoke the "iconv" program to get a list of supported
2973 character sets. If this program lives in a non-standard location, one can
2974 use this option to specify where to find it.
2976 * When natively debugging programs on PowerPC BookE processors running
2977 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2978 watchpoints, which specify a mask in addition to an address to watch.
2979 The mask specifies that some bits of an address (the bits which are
2980 reset in the mask) should be ignored when matching the address accessed
2981 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2982 section in the user manual for more details.
2984 * The new option --once causes GDBserver to stop listening for connections once
2985 the first connection is made. The listening port used by GDBserver will
2986 become available after that.
2988 * New commands "info macros" and "alias" have been added.
2990 * New function parameters suffix @entry specifies value of function parameter
2991 at the time the function got called. Entry values are available only since
2997 "!" is now an alias of the "shell" command.
2998 Note that no space is needed between "!" and SHELL COMMAND.
3002 watch EXPRESSION mask MASK_VALUE
3003 The watch command now supports the mask argument which allows creation
3004 of masked watchpoints, if the current architecture supports this feature.
3006 info auto-load-scripts [REGEXP]
3007 This command was formerly named "maintenance print section-scripts".
3008 It is now generally useful and is no longer a maintenance-only command.
3010 info macro [-all] [--] MACRO
3011 The info macro command has new options `-all' and `--'. The first for
3012 printing all definitions of a macro. The second for explicitly specifying
3013 the end of arguments and the beginning of the macro name in case the macro
3014 name starts with a hyphen.
3016 collect[/s] EXPRESSIONS
3017 The tracepoint collect command now takes an optional modifier "/s"
3018 that directs it to dereference pointer-to-character types and
3019 collect the bytes of memory up to a zero byte. The behavior is
3020 similar to what you see when you use the regular print command on a
3021 string. An optional integer following the "/s" sets a bound on the
3022 number of bytes that will be collected.
3025 The trace start command now interprets any supplied arguments as a
3026 note to be recorded with the trace run, with an effect similar to
3027 setting the variable trace-notes.
3030 The trace stop command now interprets any arguments as a note to be
3031 mentioned along with the tstatus report that the trace was stopped
3032 with a command. The effect is similar to setting the variable
3035 * Tracepoints can now be enabled and disabled at any time after a trace
3036 experiment has been started using the standard "enable" and "disable"
3037 commands. It is now possible to start a trace experiment with no enabled
3038 tracepoints; GDB will display a warning, but will allow the experiment to
3039 begin, assuming that tracepoints will be enabled as needed while the trace
3042 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3043 locations with 4-byte instructions, when they were previously
3044 limited to locations with instructions of 5 bytes or longer.
3048 set debug dwarf2-read
3049 show debug dwarf2-read
3050 Turns on or off display of debugging messages related to reading
3051 DWARF debug info. The default is off.
3053 set debug symtab-create
3054 show debug symtab-create
3055 Turns on or off display of debugging messages related to symbol table
3056 creation. The default is off.
3059 show extended-prompt
3060 Set the GDB prompt, and allow escape sequences to be inserted to
3061 display miscellaneous information (see 'help set extended-prompt'
3062 for the list of sequences). This prompt (and any information
3063 accessed through the escape sequences) is updated every time the
3064 prompt is displayed.
3066 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3067 show print entry-values
3068 Set printing of frame argument values at function entry. In some cases
3069 GDB can determine the value of function argument which was passed by the
3070 function caller, even if the value was modified inside the called function.
3072 set debug entry-values
3073 show debug entry-values
3074 Control display of debugging info for determining frame argument values at
3075 function entry and virtual tail call frames.
3077 set basenames-may-differ
3078 show basenames-may-differ
3079 Set whether a source file may have multiple base names.
3080 (A "base name" is the name of a file with the directory part removed.
3081 Example: The base name of "/home/user/hello.c" is "hello.c".)
3082 If set, GDB will canonicalize file names (e.g., expand symlinks)
3083 before comparing them. Canonicalization is an expensive operation,
3084 but it allows the same file be known by more than one base name.
3085 If not set (the default), all source files are assumed to have just
3086 one base name, and gdb will do file name comparisons more efficiently.
3092 Set a user name and notes for the current and any future trace runs.
3093 This is useful for long-running and/or disconnected traces, to
3094 inform others (or yourself) as to who is running the trace, supply
3095 contact information, or otherwise explain what is going on.
3097 set trace-stop-notes
3098 show trace-stop-notes
3099 Set a note attached to the trace run, that is displayed when the
3100 trace has been stopped by a tstop command. This is useful for
3101 instance as an explanation, if you are stopping a trace run that was
3102 started by someone else.
3104 * New remote packets
3108 Dynamically enable a tracepoint in a started trace experiment.
3112 Dynamically disable a tracepoint in a started trace experiment.
3116 Set the user and notes of the trace run.
3120 Query the current status of a tracepoint.
3124 Query the minimum length of instruction at which a fast tracepoint may
3127 * Dcache size (number of lines) and line-size are now runtime-configurable
3128 via "set dcache line" and "set dcache line-size" commands.
3132 Texas Instruments TMS320C6x tic6x-*-*
3136 Renesas RL78 rl78-*-elf
3138 *** Changes in GDB 7.3.1
3140 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3142 *** Changes in GDB 7.3
3144 * GDB has a new command: "thread find [REGEXP]".
3145 It finds the thread id whose name, target id, or thread extra info
3146 matches the given regular expression.
3148 * The "catch syscall" command now works on mips*-linux* targets.
3150 * The -data-disassemble MI command now supports modes 2 and 3 for
3151 dumping the instruction opcodes.
3153 * New command line options
3155 -data-directory DIR Specify DIR as the "data-directory".
3156 This is mostly for testing purposes.
3158 * The "maint set python auto-load on|off" command has been renamed to
3159 "set auto-load-scripts on|off".
3161 * GDB has a new command: "set directories".
3162 It is like the "dir" command except that it replaces the
3163 source path list instead of augmenting it.
3165 * GDB now understands thread names.
3167 On GNU/Linux, "info threads" will display the thread name as set by
3168 prctl or pthread_setname_np.
3170 There is also a new command, "thread name", which can be used to
3171 assign a name internally for GDB to display.
3174 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3175 has been integrated into GDB.
3179 ** The function gdb.Write now accepts an optional keyword 'stream'.
3180 This keyword, when provided, will direct the output to either
3181 stdout, stderr, or GDB's logging output.
3183 ** Parameters can now be be sub-classed in Python, and in particular
3184 you may implement the get_set_doc and get_show_doc functions.
3185 This improves how Parameter set/show documentation is processed
3186 and allows for more dynamic content.
3188 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3189 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3190 have an is_valid method.
3192 ** Breakpoints can now be sub-classed in Python, and in particular
3193 you may implement a 'stop' function that is executed each time
3194 the inferior reaches that breakpoint.
3196 ** New function gdb.lookup_global_symbol looks up a global symbol.
3198 ** GDB values in Python are now callable if the value represents a
3199 function. For example, if 'some_value' represents a function that
3200 takes two integer parameters and returns a value, you can call
3201 that function like so:
3203 result = some_value (10,20)
3205 ** Module gdb.types has been added.
3206 It contains a collection of utilities for working with gdb.Types objects:
3207 get_basic_type, has_field, make_enum_dict.
3209 ** Module gdb.printing has been added.
3210 It contains utilities for writing and registering pretty-printers.
3211 New classes: PrettyPrinter, SubPrettyPrinter,
3212 RegexpCollectionPrettyPrinter.
3213 New function: register_pretty_printer.
3215 ** New commands "info pretty-printers", "enable pretty-printer" and
3216 "disable pretty-printer" have been added.
3218 ** gdb.parameter("directories") is now available.
3220 ** New function gdb.newest_frame returns the newest frame in the
3223 ** The gdb.InferiorThread class has a new "name" attribute. This
3224 holds the thread's name.
3226 ** Python Support for Inferior events.
3227 Python scripts can add observers to be notified of events
3228 occurring in the process being debugged.
3229 The following events are currently supported:
3230 - gdb.events.cont Continue event.
3231 - gdb.events.exited Inferior exited event.
3232 - gdb.events.stop Signal received, and Breakpoint hit events.
3236 ** GDB now puts template parameters in scope when debugging in an
3237 instantiation. For example, if you have:
3239 template<int X> int func (void) { return X; }
3241 then if you step into func<5>, "print X" will show "5". This
3242 feature requires proper debuginfo support from the compiler; it
3243 was added to GCC 4.5.
3245 ** The motion commands "next", "finish", "until", and "advance" now
3246 work better when exceptions are thrown. In particular, GDB will
3247 no longer lose control of the inferior; instead, the GDB will
3248 stop the inferior at the point at which the exception is caught.
3249 This functionality requires a change in the exception handling
3250 code that was introduced in GCC 4.5.
3252 * GDB now follows GCC's rules on accessing volatile objects when
3253 reading or writing target state during expression evaluation.
3254 One notable difference to prior behavior is that "print x = 0"
3255 no longer generates a read of x; the value of the assignment is
3256 now always taken directly from the value being assigned.
3258 * GDB now has some support for using labels in the program's source in
3259 linespecs. For instance, you can use "advance label" to continue
3260 execution to a label.
3262 * GDB now has support for reading and writing a new .gdb_index
3263 section. This section holds a fast index of DWARF debugging
3264 information and can be used to greatly speed up GDB startup and
3265 operation. See the documentation for `save gdb-index' for details.
3267 * The "watch" command now accepts an optional "-location" argument.
3268 When used, this causes GDB to watch the memory referred to by the
3269 expression. Such a watchpoint is never deleted due to it going out
3272 * GDB now supports thread debugging of core dumps on GNU/Linux.
3274 GDB now activates thread debugging using the libthread_db library
3275 when debugging GNU/Linux core dumps, similarly to when debugging
3276 live processes. As a result, when debugging a core dump file, GDB
3277 is now able to display pthread_t ids of threads. For example, "info
3278 threads" shows the same output as when debugging the process when it
3279 was live. In earlier releases, you'd see something like this:
3282 * 1 LWP 6780 main () at main.c:10
3284 While now you see this:
3287 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3289 It is also now possible to inspect TLS variables when debugging core
3292 When debugging a core dump generated on a machine other than the one
3293 used to run GDB, you may need to point GDB at the correct
3294 libthread_db library with the "set libthread-db-search-path"
3295 command. See the user manual for more details on this command.
3297 * When natively debugging programs on PowerPC BookE processors running
3298 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3299 which stop execution of the inferior whenever it executes an instruction
3300 at any address within the specified range. See the "PowerPC Embedded"
3301 section in the user manual for more details.
3303 * New features in the GDB remote stub, GDBserver
3305 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3306 and i686 LynxOS (version 5.x).
3308 ** GDBserver is now supported on Blackfin Linux.
3310 * New native configurations
3312 ia64 HP-UX ia64-*-hpux*
3316 Analog Devices, Inc. Blackfin Processor bfin-*
3318 * Ada task switching is now supported on sparc-elf targets when
3319 debugging a program using the Ravenscar Profile. For more information,
3320 see the "Tasking Support when using the Ravenscar Profile" section
3321 in the GDB user manual.
3323 * Guile support was removed.
3325 * New features in the GNU simulator
3327 ** The --map-info flag lists all known core mappings.
3329 ** CFI flashes may be simulated via the "cfi" device.
3331 *** Changes in GDB 7.2
3333 * Shared library support for remote targets by default
3335 When GDB is configured for a generic, non-OS specific target, like
3336 for example, --target=arm-eabi or one of the many *-*-elf targets,
3337 GDB now queries remote stubs for loaded shared libraries using the
3338 `qXfer:libraries:read' packet. Previously, shared library support
3339 was always disabled for such configurations.
3343 ** Argument Dependent Lookup (ADL)
3345 In C++ ADL lookup directs function search to the namespaces of its
3346 arguments even if the namespace has not been imported.
3356 Here the compiler will search for `foo' in the namespace of 'b'
3357 and find A::foo. GDB now supports this. This construct is commonly
3358 used in the Standard Template Library for operators.
3360 ** Improved User Defined Operator Support
3362 In addition to member operators, GDB now supports lookup of operators
3363 defined in a namespace and imported with a `using' directive, operators
3364 defined in the global scope, operators imported implicitly from an
3365 anonymous namespace, and the ADL operators mentioned in the previous
3367 GDB now also supports proper overload resolution for all the previously
3368 mentioned flavors of operators.
3370 ** static const class members
3372 Printing of static const class members that are initialized in the
3373 class definition has been fixed.
3375 * Windows Thread Information Block access.
3377 On Windows targets, GDB now supports displaying the Windows Thread
3378 Information Block (TIB) structure. This structure is visible either
3379 by using the new command `info w32 thread-information-block' or, by
3380 dereferencing the new convenience variable named `$_tlb', a
3381 thread-specific pointer to the TIB. This feature is also supported
3382 when remote debugging using GDBserver.
3384 * Static tracepoints
3386 Static tracepoints are calls in the user program into a tracing
3387 library. One such library is a port of the LTTng kernel tracer to
3388 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3389 When debugging with GDBserver, GDB now supports combining the GDB
3390 tracepoint machinery with such libraries. For example: the user can
3391 use GDB to probe a static tracepoint marker (a call from the user
3392 program into the tracing library) with the new "strace" command (see
3393 "New commands" below). This creates a "static tracepoint" in the
3394 breakpoint list, that can be manipulated with the same feature set
3395 as fast and regular tracepoints. E.g., collect registers, local and
3396 global variables, collect trace state variables, and define
3397 tracepoint conditions. In addition, the user can collect extra
3398 static tracepoint marker specific data, by collecting the new
3399 $_sdata internal variable. When analyzing the trace buffer, you can
3400 inspect $_sdata like any other variable available to GDB. For more
3401 information, see the "Tracepoints" chapter in GDB user manual. New
3402 remote packets have been defined to support static tracepoints, see
3403 the "New remote packets" section below.
3405 * Better reconstruction of tracepoints after disconnected tracing
3407 GDB will attempt to download the original source form of tracepoint
3408 definitions when starting a trace run, and then will upload these
3409 upon reconnection to the target, resulting in a more accurate
3410 reconstruction of the tracepoints that are in use on the target.
3414 You can now exercise direct control over the ways that GDB can
3415 affect your program. For instance, you can disallow the setting of
3416 breakpoints, so that the program can run continuously (assuming
3417 non-stop mode). In addition, the "observer" variable is available
3418 to switch all of the different controls; in observer mode, GDB
3419 cannot affect the target's behavior at all, which is useful for
3420 tasks like diagnosing live systems in the field.
3422 * The new convenience variable $_thread holds the number of the
3425 * New remote packets
3429 Return the address of the Windows Thread Information Block of a given thread.
3433 In response to several of the tracepoint packets, the target may now
3434 also respond with a number of intermediate `qRelocInsn' request
3435 packets before the final result packet, to have GDB handle
3436 relocating an instruction to execute at a different address. This
3437 is particularly useful for stubs that support fast tracepoints. GDB
3438 reports support for this feature in the qSupported packet.
3442 List static tracepoint markers in the target program.
3446 List static tracepoint markers at a given address in the target
3449 qXfer:statictrace:read
3451 Read the static trace data collected (by a `collect $_sdata'
3452 tracepoint action). The remote stub reports support for this packet
3453 to gdb's qSupported query.
3457 Send the current settings of GDB's permission flags.
3461 Send part of the source (textual) form of a tracepoint definition,
3462 which includes location, conditional, and action list.
3464 * The source command now accepts a -s option to force searching for the
3465 script in the source search path even if the script name specifies
3468 * New features in the GDB remote stub, GDBserver
3470 - GDBserver now support tracepoints (including fast tracepoints, and
3471 static tracepoints). The feature is currently supported by the
3472 i386-linux and amd64-linux builds. See the "Tracepoints support
3473 in gdbserver" section in the manual for more information.
3475 GDBserver JIT compiles the tracepoint's conditional agent
3476 expression bytecode into native code whenever possible for low
3477 overhead dynamic tracepoints conditionals. For such tracepoints,
3478 an expression that examines program state is evaluated when the
3479 tracepoint is reached, in order to determine whether to capture
3480 trace data. If the condition is simple and false, processing the
3481 tracepoint finishes very quickly and no data is gathered.
3483 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3484 for static tracepoints support.
3486 - GDBserver now supports x86_64 Windows 64-bit debugging.
3488 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3489 it understands register description.
3491 * The --batch flag now disables pagination and queries.
3493 * X86 general purpose registers
3495 GDB now supports reading/writing byte, word and double-word x86
3496 general purpose registers directly. This means you can use, say,
3497 $ah or $ax to refer, respectively, to the byte register AH and
3498 16-bit word register AX that are actually portions of the 32-bit
3499 register EAX or 64-bit register RAX.
3501 * The `commands' command now accepts a range of breakpoints to modify.
3502 A plain `commands' following a command that creates multiple
3503 breakpoints affects all the breakpoints set by that command. This
3504 applies to breakpoints set by `rbreak', and also applies when a
3505 single `break' command creates multiple breakpoints (e.g.,
3506 breakpoints on overloaded c++ functions).
3508 * The `rbreak' command now accepts a filename specification as part of
3509 its argument, limiting the functions selected by the regex to those
3510 in the specified file.
3512 * Support for remote debugging Windows and SymbianOS shared libraries
3513 from Unix hosts has been improved. Non Windows GDB builds now can
3514 understand target reported file names that follow MS-DOS based file
3515 system semantics, such as file names that include drive letters and
3516 use the backslash character as directory separator. This makes it
3517 possible to transparently use the "set sysroot" and "set
3518 solib-search-path" on Unix hosts to point as host copies of the
3519 target's shared libraries. See the new command "set
3520 target-file-system-kind" described below, and the "Commands to
3521 specify files" section in the user manual for more information.
3525 eval template, expressions...
3526 Convert the values of one or more expressions under the control
3527 of the string template to a command line, and call it.
3529 set target-file-system-kind unix|dos-based|auto
3530 show target-file-system-kind
3531 Set or show the assumed file system kind for target reported file
3534 save breakpoints <filename>
3535 Save all current breakpoint definitions to a file suitable for use
3536 in a later debugging session. To read the saved breakpoint
3537 definitions, use the `source' command.
3539 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3542 info static-tracepoint-markers
3543 Display information about static tracepoint markers in the target.
3545 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3546 Define a static tracepoint by probing a marker at the given
3547 function, line, address, or marker ID.
3551 Enable and disable observer mode.
3553 set may-write-registers on|off
3554 set may-write-memory on|off
3555 set may-insert-breakpoints on|off
3556 set may-insert-tracepoints on|off
3557 set may-insert-fast-tracepoints on|off
3558 set may-interrupt on|off
3559 Set individual permissions for GDB effects on the target. Note that
3560 some of these settings can have undesirable or surprising
3561 consequences, particularly when changed in the middle of a session.
3562 For instance, disabling the writing of memory can prevent
3563 breakpoints from being inserted, cause single-stepping to fail, or
3564 even crash your program, if you disable after breakpoints have been
3565 inserted. However, GDB should not crash.
3567 set record memory-query on|off
3568 show record memory-query
3569 Control whether to stop the inferior if memory changes caused
3570 by an instruction cannot be recorded.
3575 The disassemble command now supports "start,+length" form of two arguments.
3579 ** GDB now provides a new directory location, called the python directory,
3580 where Python scripts written for GDB can be installed. The location
3581 of that directory is <data-directory>/python, where <data-directory>
3582 is the GDB data directory. For more details, see section `Scripting
3583 GDB using Python' in the manual.
3585 ** The GDB Python API now has access to breakpoints, symbols, symbol
3586 tables, program spaces, inferiors, threads and frame's code blocks.
3587 Additionally, GDB Parameters can now be created from the API, and
3588 manipulated via set/show in the CLI.
3590 ** New functions gdb.target_charset, gdb.target_wide_charset,
3591 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3593 ** New exception gdb.GdbError.
3595 ** Pretty-printers are now also looked up in the current program space.
3597 ** Pretty-printers can now be individually enabled and disabled.
3599 ** GDB now looks for names of Python scripts to auto-load in a
3600 special section named `.debug_gdb_scripts', in addition to looking
3601 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3603 * Tracepoint actions were unified with breakpoint commands. In particular,
3604 there are no longer differences in "info break" output for breakpoints and
3605 tracepoints and the "commands" command can be used for both tracepoints and
3606 regular breakpoints.
3610 ARM Symbian arm*-*-symbianelf*
3612 * D language support.
3613 GDB now supports debugging programs written in the D programming
3616 * GDB now supports the extended ptrace interface for PowerPC which is
3617 available since Linux kernel version 2.6.34. This automatically enables
3618 any hardware breakpoints and additional hardware watchpoints available in
3619 the processor. The old ptrace interface exposes just one hardware
3620 watchpoint and no hardware breakpoints.
3622 * GDB is now able to use the Data Value Compare (DVC) register available on
3623 embedded PowerPC processors to implement in hardware simple watchpoint
3624 conditions of the form:
3626 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3628 This works in native GDB running on Linux kernels with the extended ptrace
3629 interface mentioned above.
3631 *** Changes in GDB 7.1
3635 ** Namespace Support
3637 GDB now supports importing of namespaces in C++. This enables the
3638 user to inspect variables from imported namespaces. Support for
3639 namepace aliasing has also been added. So, if a namespace is
3640 aliased in the current scope (e.g. namepace C=A; ) the user can
3641 print variables using the alias (e.g. (gdb) print C::x).
3645 All known bugs relating to the printing of virtual base class were
3646 fixed. It is now possible to call overloaded static methods using a
3651 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3652 and reinterpret_cast<> are now handled by the C++ expression parser.
3656 Xilinx MicroBlaze microblaze-*-*
3661 Xilinx MicroBlaze microblaze
3664 * Multi-program debugging.
3666 GDB now has support for multi-program (a.k.a. multi-executable or
3667 multi-exec) debugging. This allows for debugging multiple inferiors
3668 simultaneously each running a different program under the same GDB
3669 session. See "Debugging Multiple Inferiors and Programs" in the
3670 manual for more information. This implied some user visible changes
3671 in the multi-inferior support. For example, "info inferiors" now
3672 lists inferiors that are not running yet or that have exited
3673 already. See also "New commands" and "New options" below.
3675 * New tracing features
3677 GDB's tracepoint facility now includes several new features:
3679 ** Trace state variables
3681 GDB tracepoints now include support for trace state variables, which
3682 are variables managed by the target agent during a tracing
3683 experiment. They are useful for tracepoints that trigger each
3684 other, so for instance one tracepoint can count hits in a variable,
3685 and then a second tracepoint has a condition that is true when the
3686 count reaches a particular value. Trace state variables share the
3687 $-syntax of GDB convenience variables, and can appear in both
3688 tracepoint actions and condition expressions. Use the "tvariable"
3689 command to create, and "info tvariables" to view; see "Trace State
3690 Variables" in the manual for more detail.
3694 GDB now includes an option for defining fast tracepoints, which
3695 targets may implement more efficiently, such as by installing a jump
3696 into the target agent rather than a trap instruction. The resulting
3697 speedup can be by two orders of magnitude or more, although the
3698 tradeoff is that some program locations on some target architectures
3699 might not allow fast tracepoint installation, for instance if the
3700 instruction to be replaced is shorter than the jump. To request a
3701 fast tracepoint, use the "ftrace" command, with syntax identical to
3702 the regular trace command.
3704 ** Disconnected tracing
3706 It is now possible to detach GDB from the target while it is running
3707 a trace experiment, then reconnect later to see how the experiment
3708 is going. In addition, a new variable disconnected-tracing lets you
3709 tell the target agent whether to continue running a trace if the
3710 connection is lost unexpectedly.
3714 GDB now has the ability to save the trace buffer into a file, and
3715 then use that file as a target, similarly to you can do with
3716 corefiles. You can select trace frames, print data that was
3717 collected in them, and use tstatus to display the state of the
3718 tracing run at the moment that it was saved. To create a trace
3719 file, use "tsave <filename>", and to use it, do "target tfile
3722 ** Circular trace buffer
3724 You can ask the target agent to handle the trace buffer as a
3725 circular buffer, discarding the oldest trace frames to make room for
3726 newer ones, by setting circular-trace-buffer to on. This feature may
3727 not be available for all target agents.
3732 The disassemble command, when invoked with two arguments, now requires
3733 the arguments to be comma-separated.
3736 The info variables command now displays variable definitions. Files
3737 which only declare a variable are not shown.
3740 The source command is now capable of sourcing Python scripts.
3741 This feature is dependent on the debugger being build with Python
3744 Related to this enhancement is also the introduction of a new command
3745 "set script-extension" (see below).
3747 * New commands (for set/show, see "New options" below)
3749 record save [<FILENAME>]
3750 Save a file (in core file format) containing the process record
3751 execution log for replay debugging at a later time.
3753 record restore <FILENAME>
3754 Restore the process record execution log that was saved at an
3755 earlier time, for replay debugging.
3757 add-inferior [-copies <N>] [-exec <FILENAME>]
3760 clone-inferior [-copies <N>] [ID]
3761 Make a new inferior ready to execute the same program another
3762 inferior has loaded.
3767 maint info program-spaces
3768 List the program spaces loaded into GDB.
3770 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3771 show remote interrupt-sequence
3772 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3773 as the sequence to the remote target in order to interrupt the execution.
3774 Ctrl-C is a default. Some system prefers BREAK which is high level of
3775 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3776 Magic SysRq g. It is BREAK signal and character 'g'.
3778 set remote interrupt-on-connect [on | off]
3779 show remote interrupt-on-connect
3780 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3781 remote target when gdb connects to it. This is needed when you debug
3784 set remotebreak [on | off]
3786 Deprecated. Use "set/show remote interrupt-sequence" instead.
3788 tvariable $NAME [ = EXP ]
3789 Create or modify a trace state variable.
3792 List trace state variables and their values.
3794 delete tvariable $NAME ...
3795 Delete one or more trace state variables.
3798 Evaluate the given expressions without collecting anything into the
3799 trace buffer. (Valid in tracepoint actions only.)
3801 ftrace FN / FILE:LINE / *ADDR
3802 Define a fast tracepoint at the given function, line, or address.
3804 * New expression syntax
3806 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3807 GDB now parses 0b101010 identically with 42.
3811 set follow-exec-mode new|same
3812 show follow-exec-mode
3813 Control whether GDB reuses the same inferior across an exec call or
3814 creates a new one. This is useful to be able to restart the old
3815 executable after the inferior having done an exec call.
3817 set default-collect EXPR, ...
3818 show default-collect
3819 Define a list of expressions to be collected at each tracepoint.
3820 This is a useful way to ensure essential items are not overlooked,
3821 such as registers or a critical global variable.
3823 set disconnected-tracing
3824 show disconnected-tracing
3825 If set to 1, the target is instructed to continue tracing if it
3826 loses its connection to GDB. If 0, the target is to stop tracing
3829 set circular-trace-buffer
3830 show circular-trace-buffer
3831 If set to on, the target is instructed to use a circular trace buffer
3832 and discard the oldest trace frames instead of stopping the trace due
3833 to a full trace buffer. If set to off, the trace stops when the buffer
3834 fills up. Some targets may not support this.
3836 set script-extension off|soft|strict
3837 show script-extension
3838 If set to "off", the debugger does not perform any script language
3839 recognition, and all sourced files are assumed to be GDB scripts.
3840 If set to "soft" (the default), files are sourced according to
3841 filename extension, falling back to GDB scripts if the first
3843 If set to "strict", files are sourced according to filename extension.
3845 set ada trust-PAD-over-XVS on|off
3846 show ada trust-PAD-over-XVS
3847 If off, activate a workaround against a bug in the debugging information
3848 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3849 the GCC sources for more information about the GNAT encoding and
3850 PAD types in particular). It is always safe to set this option to
3851 off, but this introduces a slight performance penalty. The default
3854 * Python API Improvements
3856 ** GDB provides the new class gdb.LazyString. This is useful in
3857 some pretty-printing cases. The new method gdb.Value.lazy_string
3858 provides a simple way to create objects of this type.
3860 ** The fields returned by gdb.Type.fields now have an
3861 `is_base_class' attribute.
3863 ** The new method gdb.Type.range returns the range of an array type.
3865 ** The new method gdb.parse_and_eval can be used to parse and
3866 evaluate an expression.
3868 * New remote packets
3871 Define a trace state variable.
3874 Get the current value of a trace state variable.
3877 Set desired tracing behavior upon disconnection.
3880 Set the trace buffer to be linear or circular.
3883 Get data about the tracepoints currently in use.
3887 Process record now works correctly with hardware watchpoints.
3889 Multiple bug fixes have been made to the mips-irix port, making it
3890 much more reliable. In particular:
3891 - Debugging threaded applications is now possible again. Previously,
3892 GDB would hang while starting the program, or while waiting for
3893 the program to stop at a breakpoint.
3894 - Attaching to a running process no longer hangs.
3895 - An error occurring while loading a core file has been fixed.
3896 - Changing the value of the PC register now works again. This fixes
3897 problems observed when using the "jump" command, or when calling
3898 a function from GDB, or even when assigning a new value to $pc.
3899 - With the "finish" and "return" commands, the return value for functions
3900 returning a small array is now correctly printed.
3901 - It is now possible to break on shared library code which gets executed
3902 during a shared library init phase (code executed while executing
3903 their .init section). Previously, the breakpoint would have no effect.
3904 - GDB is now able to backtrace through the signal handler for
3905 non-threaded programs.
3907 PIE (Position Independent Executable) programs debugging is now supported.
3908 This includes debugging execution of PIC (Position Independent Code) shared
3909 libraries although for that, it should be possible to run such libraries as an
3912 *** Changes in GDB 7.0
3914 * GDB now has an interface for JIT compilation. Applications that
3915 dynamically generate code can create symbol files in memory and register
3916 them with GDB. For users, the feature should work transparently, and
3917 for JIT developers, the interface is documented in the GDB manual in the
3918 "JIT Compilation Interface" chapter.
3920 * Tracepoints may now be conditional. The syntax is as for
3921 breakpoints; either an "if" clause appended to the "trace" command,
3922 or the "condition" command is available. GDB sends the condition to
3923 the target for evaluation using the same bytecode format as is used
3924 for tracepoint actions.
3926 * The disassemble command now supports: an optional /r modifier, print the
3927 raw instructions in hex as well as in symbolic form, and an optional /m
3928 modifier to print mixed source+assembly.
3930 * Process record and replay
3932 In a architecture environment that supports ``process record and
3933 replay'', ``process record and replay'' target can record a log of
3934 the process execution, and replay it with both forward and reverse
3937 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3938 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3939 set execution-direction {forward|reverse}, for targets that support
3942 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3943 feature is available with a native GDB running on kernel version
3946 * GDB now has support for multi-byte and wide character sets on the
3947 target. Strings whose character type is wchar_t, char16_t, or
3948 char32_t are now correctly printed. GDB supports wide- and unicode-
3949 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3950 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3951 `printf'. This feature requires iconv to work properly; if your
3952 system does not have a working iconv, GDB can use GNU libiconv. See
3953 the installation instructions for more information.
3955 * GDB now supports automatic retrieval of shared library files from
3956 remote targets. To use this feature, specify a system root that begins
3957 with the `remote:' prefix, either via the `set sysroot' command or via
3958 the `--with-sysroot' configure-time option.
3960 * "info sharedlibrary" now takes an optional regex of libraries to show,
3961 and it now reports if a shared library has no debugging information.
3963 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3964 now complete on file names.
3966 * When completing in expressions, gdb will attempt to limit
3967 completions to allowable structure or union fields, where appropriate.
3968 For instance, consider:
3970 # struct example { int f1; double f2; };
3971 # struct example variable;
3974 If the user types TAB at the end of this command line, the available
3975 completions will be "f1" and "f2".
3977 * Inlined functions are now supported. They show up in backtraces, and
3978 the "step", "next", and "finish" commands handle them automatically.
3980 * GDB now supports the token-splicing (##) and stringification (#)
3981 operators when expanding macros. It also supports variable-arity
3984 * GDB now supports inspecting extra signal information, exported by
3985 the new $_siginfo convenience variable. The feature is currently
3986 implemented on linux ARM, i386 and amd64.
3988 * GDB can now display the VFP floating point registers and NEON vector
3989 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3990 can provide these registers (requires Linux 2.6.30 or later). Remote
3991 and simulator targets may also provide them.
3993 * New remote packets
3996 Search memory for a sequence of bytes.
3999 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4000 operation over reliable transport links. Use of this packet is
4001 controlled by the `set remote noack-packet' command.
4004 Kill the process with the specified process ID. Use this in preference
4005 to `k' when multiprocess protocol extensions are supported.
4008 Obtains additional operating system information
4012 Read or write additional signal information.
4014 * Removed remote protocol undocumented extension
4016 An undocumented extension to the remote protocol's `S' stop reply
4017 packet that permited the stub to pass a process id was removed.
4018 Remote servers should use the `T' stop reply packet instead.
4020 * GDB now supports multiple function calling conventions according to the
4021 DWARF-2 DW_AT_calling_convention function attribute.
4023 * The SH target utilizes the aforementioned change to distinguish between gcc
4024 and Renesas calling convention. It also adds the new CLI commands
4025 `set/show sh calling-convention'.
4027 * GDB can now read compressed debug sections, as produced by GNU gold
4028 with the --compress-debug-sections=zlib flag.
4030 * 64-bit core files are now supported on AIX.
4032 * Thread switching is now supported on Tru64.
4034 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4035 which will be allocated using malloc later in program execution.
4037 * The qXfer:libraries:read remote procotol packet now allows passing a
4038 list of section offsets.
4040 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4041 conditions handling signals delivered during attach or thread creation
4042 have also been fixed.
4044 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4045 From the user's standpoint, all unqualified instances of True and False
4046 are treated as the standard definitions, regardless of context.
4048 * GDB now parses C++ symbol and type names more flexibly. For
4051 template<typename T> class C { };
4054 GDB will now correctly handle all of:
4056 ptype C<char const *>
4057 ptype C<char const*>
4058 ptype C<const char *>
4059 ptype C<const char*>
4061 * New features in the GDB remote stub, gdbserver
4063 - The "--wrapper" command-line argument tells gdbserver to use a
4064 wrapper program to launch programs for debugging.
4066 - On PowerPC and S/390 targets, it is now possible to use a single
4067 gdbserver executable to debug both 32-bit and 64-bit programs.
4068 (This requires gdbserver itself to be built as a 64-bit executable.)
4070 - gdbserver uses the new noack protocol mode for TCP connections to
4071 reduce communications latency, if also supported and enabled in GDB.
4073 - Support for the sparc64-linux-gnu target is now included in
4076 - The amd64-linux build of gdbserver now supports debugging both
4077 32-bit and 64-bit programs.
4079 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4080 now support hardware watchpoints, and will use them automatically
4085 GDB now has support for scripting using Python. Whether this is
4086 available is determined at configure time.
4088 New GDB commands can now be written in Python.
4090 * Ada tasking support
4092 Ada tasks can now be inspected in GDB. The following commands have
4096 Print the list of Ada tasks.
4098 Print detailed information about task number N.
4100 Print the task number of the current task.
4102 Switch the context of debugging to task number N.
4104 * Support for user-defined prefixed commands. The "define" command can
4105 add new commands to existing prefixes, e.g. "target".
4107 * Multi-inferior, multi-process debugging.
4109 GDB now has generalized support for multi-inferior debugging. See
4110 "Debugging Multiple Inferiors" in the manual for more information.
4111 Although availability still depends on target support, the command
4112 set is more uniform now. The GNU/Linux specific multi-forks support
4113 has been migrated to this new framework. This implied some user
4114 visible changes; see "New commands" and also "Removed commands"
4117 * Target descriptions can now describe the target OS ABI. See the
4118 "Target Description Format" section in the user manual for more
4121 * Target descriptions can now describe "compatible" architectures
4122 to indicate that the target can execute applications for a different
4123 architecture in addition to those for the main target architecture.
4124 See the "Target Description Format" section in the user manual for
4127 * Multi-architecture debugging.
4129 GDB now includes general supports for debugging applications on
4130 hybrid systems that use more than one single processor architecture
4131 at the same time. Each such hybrid architecture still requires
4132 specific support to be added. The only hybrid architecture supported
4133 in this version of GDB is the Cell Broadband Engine.
4135 * GDB now supports integrated debugging of Cell/B.E. applications that
4136 use both the PPU and SPU architectures. To enable support for hybrid
4137 Cell/B.E. debugging, you need to configure GDB to support both the
4138 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4139 --enable-targets configure option.
4141 * Non-stop mode debugging.
4143 For some targets, GDB now supports an optional mode of operation in
4144 which you can examine stopped threads while other threads continue
4145 to execute freely. This is referred to as non-stop mode, with the
4146 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4147 section in the user manual for more information.
4149 To be able to support remote non-stop debugging, a remote stub needs
4150 to implement the non-stop mode remote protocol extensions, as
4151 described in the "Remote Non-Stop" section of the user manual. The
4152 GDB remote stub, gdbserver, has been adjusted to support these
4153 extensions on linux targets.
4155 * New commands (for set/show, see "New options" below)
4157 catch syscall [NAME(S) | NUMBER(S)]
4158 Catch system calls. Arguments, which should be names of system
4159 calls or their numbers, mean catch only those syscalls. Without
4160 arguments, every syscall will be caught. When the inferior issues
4161 any of the specified syscalls, GDB will stop and announce the system
4162 call, both when it is called and when its call returns. This
4163 feature is currently available with a native GDB running on the
4164 Linux Kernel, under the following architectures: x86, x86_64,
4165 PowerPC and PowerPC64.
4167 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4169 Search memory for a sequence of bytes.
4171 maint set python print-stack
4172 maint show python print-stack
4173 Show a stack trace when an error is encountered in a Python script.
4176 Invoke CODE by passing it to the Python interpreter.
4181 These allow macros to be defined, undefined, and listed
4185 Show operating system information about processes.
4188 List the inferiors currently under GDB's control.
4191 Switch focus to inferior number NUM.
4194 Detach from inferior number NUM.
4197 Kill inferior number NUM.
4201 set spu stop-on-load
4202 show spu stop-on-load
4203 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4205 set spu auto-flush-cache
4206 show spu auto-flush-cache
4207 Control whether to automatically flush the software-managed cache
4208 during Cell/B.E. debugging.
4210 set sh calling-convention
4211 show sh calling-convention
4212 Control the calling convention used when calling SH target functions.
4215 show debug timestamp
4216 Control display of timestamps with GDB debugging output.
4218 set disassemble-next-line
4219 show disassemble-next-line
4220 Control display of disassembled source lines or instructions when
4223 set remote noack-packet
4224 show remote noack-packet
4225 Set/show the use of remote protocol QStartNoAckMode packet. See above
4226 under "New remote packets."
4228 set remote query-attached-packet
4229 show remote query-attached-packet
4230 Control use of remote protocol `qAttached' (query-attached) packet.
4232 set remote read-siginfo-object
4233 show remote read-siginfo-object
4234 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4237 set remote write-siginfo-object
4238 show remote write-siginfo-object
4239 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4242 set remote reverse-continue
4243 show remote reverse-continue
4244 Control use of remote protocol 'bc' (reverse-continue) packet.
4246 set remote reverse-step
4247 show remote reverse-step
4248 Control use of remote protocol 'bs' (reverse-step) packet.
4250 set displaced-stepping
4251 show displaced-stepping
4252 Control displaced stepping mode. Displaced stepping is a way to
4253 single-step over breakpoints without removing them from the debuggee.
4254 Also known as "out-of-line single-stepping".
4257 show debug displaced
4258 Control display of debugging info for displaced stepping.
4260 maint set internal-error
4261 maint show internal-error
4262 Control what GDB does when an internal error is detected.
4264 maint set internal-warning
4265 maint show internal-warning
4266 Control what GDB does when an internal warning is detected.
4271 Use a wrapper program to launch programs for debugging.
4273 set multiple-symbols (all|ask|cancel)
4274 show multiple-symbols
4275 The value of this variable can be changed to adjust the debugger behavior
4276 when an expression or a breakpoint location contains an ambiguous symbol
4277 name (an overloaded function name, for instance).
4279 set breakpoint always-inserted
4280 show breakpoint always-inserted
4281 Keep breakpoints always inserted in the target, as opposed to inserting
4282 them when resuming the target, and removing them when the target stops.
4283 This option can improve debugger performance on slow remote targets.
4285 set arm fallback-mode (arm|thumb|auto)
4286 show arm fallback-mode
4287 set arm force-mode (arm|thumb|auto)
4289 These commands control how ARM GDB determines whether instructions
4290 are ARM or Thumb. The default for both settings is auto, which uses
4291 the current CPSR value for instructions without symbols; previous
4292 versions of GDB behaved as if "set arm fallback-mode arm".
4294 set disable-randomization
4295 show disable-randomization
4296 Standalone programs run with the virtual address space randomization enabled
4297 by default on some platforms. This option keeps the addresses stable across
4298 multiple debugging sessions.
4302 Control whether other threads are stopped or not when some thread hits
4307 Requests that asynchronous execution is enabled in the target, if available.
4308 In this case, it's possible to resume target in the background, and interact
4309 with GDB while the target is running. "show target-async" displays the
4310 current state of asynchronous execution of the target.
4312 set target-wide-charset
4313 show target-wide-charset
4314 The target-wide-charset is the name of the character set that GDB
4315 uses when printing characters whose type is wchar_t.
4317 set tcp auto-retry (on|off)
4319 set tcp connect-timeout
4320 show tcp connect-timeout
4321 These commands allow GDB to retry failed TCP connections to a remote stub
4322 with a specified timeout period; this is useful if the stub is launched
4323 in parallel with GDB but may not be ready to accept connections immediately.
4325 set libthread-db-search-path
4326 show libthread-db-search-path
4327 Control list of directories which GDB will search for appropriate
4330 set schedule-multiple (on|off)
4331 show schedule-multiple
4332 Allow GDB to resume all threads of all processes or only threads of
4333 the current process.
4337 Use more aggressive caching for accesses to the stack. This improves
4338 performance of remote debugging (particularly backtraces) without
4339 affecting correctness.
4341 set interactive-mode (on|off|auto)
4342 show interactive-mode
4343 Control whether GDB runs in interactive mode (on) or not (off).
4344 When in interactive mode, GDB waits for the user to answer all
4345 queries. Otherwise, GDB does not wait and assumes the default
4346 answer. When set to auto (the default), GDB determines which
4347 mode to use based on the stdin settings.
4352 For program forks, this is replaced by the new more generic `info
4353 inferiors' command. To list checkpoints, you can still use the
4354 `info checkpoints' command, which was an alias for the `info forks'
4358 Replaced by the new `inferior' command. To switch between
4359 checkpoints, you can still use the `restart' command, which was an
4360 alias for the `fork' command.
4363 This is removed, since some targets don't have a notion of
4364 processes. To switch between processes, you can still use the
4365 `inferior' command using GDB's own inferior number.
4368 For program forks, this is replaced by the new more generic `kill
4369 inferior' command. To delete a checkpoint, you can still use the
4370 `delete checkpoint' command, which was an alias for the `delete
4374 For program forks, this is replaced by the new more generic `detach
4375 inferior' command. To detach a checkpoint, you can still use the
4376 `detach checkpoint' command, which was an alias for the `detach
4379 * New native configurations
4381 x86/x86_64 Darwin i[34567]86-*-darwin*
4383 x86_64 MinGW x86_64-*-mingw*
4387 Lattice Mico32 lm32-*
4388 x86 DICOS i[34567]86-*-dicos*
4389 x86_64 DICOS x86_64-*-dicos*
4392 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4393 (mingw32ce) debugging.
4399 These commands were actually not implemented on any target.
4401 *** Changes in GDB 6.8
4403 * New native configurations
4405 NetBSD/hppa hppa*-*netbsd*
4406 Xtensa GNU/Linux xtensa*-*-linux*
4410 NetBSD/hppa hppa*-*-netbsd*
4411 Xtensa GNU/Lunux xtensa*-*-linux*
4413 * Change in command line behavior -- corefiles vs. process ids.
4415 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4416 attaching to process NUMBER fails, GDB no longer attempts to open a
4417 core file named NUMBER. Attaching to a program using the -c option
4418 is no longer supported. Instead, use the '-p' or '--pid' options.
4420 * GDB can now be built as a native debugger for debugging Windows x86
4421 (mingw32) Portable Executable (PE) programs.
4423 * Pending breakpoints no longer change their number when their address
4426 * GDB now supports breakpoints with multiple locations,
4427 including breakpoints on C++ constructors, inside C++ templates,
4428 and in inlined functions.
4430 * GDB's ability to debug optimized code has been improved. GDB more
4431 accurately identifies function bodies and lexical blocks that occupy
4432 more than one contiguous range of addresses.
4434 * Target descriptions can now describe registers for PowerPC.
4436 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4437 registers on PowerPC targets.
4439 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4440 targets even when the libthread_db library is not available.
4442 * The GDB remote stub, gdbserver, now supports the new file transfer
4443 commands (remote put, remote get, and remote delete).
4445 * The GDB remote stub, gdbserver, now supports run and attach in
4446 extended-remote mode.
4448 * hppa*64*-*-hpux11* target broken
4449 The debugger is unable to start a program and fails with the following
4450 error: "Error trying to get information about dynamic linker".
4451 The gdb-6.7 release is also affected.
4453 * GDB now supports the --enable-targets= configure option to allow
4454 building a single GDB executable that supports multiple remote
4455 target architectures.
4457 * GDB now supports debugging C and C++ programs which use the
4458 Decimal Floating Point extension. In addition, the PowerPC target
4459 now has a set of pseudo-registers to inspect decimal float values
4460 stored in two consecutive float registers.
4462 * The -break-insert MI command can optionally create pending
4465 * Improved support for debugging Ada
4466 Many improvements to the Ada language support have been made. These
4468 - Better support for Ada2005 interface types
4469 - Improved handling of arrays and slices in general
4470 - Better support for Taft-amendment types
4471 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4473 - Improved command completion in Ada
4476 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4481 set print frame-arguments (all|scalars|none)
4482 show print frame-arguments
4483 The value of this variable can be changed to control which argument
4484 values should be printed by the debugger when displaying a frame.
4489 Transfer files to and from a remote target, and delete remote files.
4496 Transfer files to and from a remote target, and delete remote files.
4498 * New remote packets
4505 Open, close, read, write, and delete files on the remote system.
4508 Attach to an existing process on the remote system, in extended-remote
4512 Run a new process on the remote system, in extended-remote mode.
4514 *** Changes in GDB 6.7
4516 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4517 bfd, libiberty and opcodes, as revealed by static analysis donated by
4518 Coverity, Inc. (http://scan.coverity.com).
4520 * When looking up multiply-defined global symbols, GDB will now prefer the
4521 symbol definition in the current shared library if it was built using the
4522 -Bsymbolic linker option.
4524 * When the Text User Interface (TUI) is not configured, GDB will now
4525 recognize the -tui command-line option and print a message that the TUI
4528 * The GDB remote stub, gdbserver, now has lower overhead for high
4529 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4531 * GDB for MIPS targets now autodetects whether a remote target provides
4532 32-bit or 64-bit register values.
4534 * Support for C++ member pointers has been improved.
4536 * GDB now understands XML target descriptions, which specify the
4537 target's overall architecture. GDB can read a description from
4538 a local file or over the remote serial protocol.
4540 * Vectors of single-byte data use a new integer type which is not
4541 automatically displayed as character or string data.
4543 * The /s format now works with the print command. It displays
4544 arrays of single-byte integers and pointers to single-byte integers
4547 * Target descriptions can now describe target-specific registers,
4548 for architectures which have implemented the support (currently
4549 only ARM, M68K, and MIPS).
4551 * GDB and the GDB remote stub, gdbserver, now support the XScale
4554 * The GDB remote stub, gdbserver, has been updated to support
4555 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4556 has been rewritten to use the standard GDB remote protocol.
4558 * GDB can now step into C++ functions which are called through thunks.
4560 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4562 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4563 layout. It also supports a TextSeg= and DataSeg= response when only
4564 segment base addresses (rather than offsets) are available.
4566 * The /i format now outputs any trailing branch delay slot instructions
4567 immediately following the last instruction within the count specified.
4569 * The GDB remote protocol "T" stop reply packet now supports a
4570 "library" response. Combined with the new "qXfer:libraries:read"
4571 packet, this response allows GDB to debug shared libraries on targets
4572 where the operating system manages the list of loaded libraries (e.g.
4573 Windows and SymbianOS).
4575 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4576 (DLLs) on Windows and Windows CE targets.
4578 * GDB now supports a faster verification that a .debug file matches its binary
4579 according to its build-id signature, if the signature is present.
4585 Enable or disable hardware flow control (RTS/CTS) on the serial port
4586 when debugging using remote targets.
4588 set mem inaccessible-by-default
4589 show mem inaccessible-by-default
4590 If the target supplies a memory map, for instance via the remote
4591 protocol's "qXfer:memory-map:read" packet, setting this variable
4592 prevents GDB from accessing memory outside the memory map. This
4593 is useful for targets with memory mapped registers or which react
4594 badly to accesses of unmapped address space.
4596 set breakpoint auto-hw
4597 show breakpoint auto-hw
4598 If the target supplies a memory map, for instance via the remote
4599 protocol's "qXfer:memory-map:read" packet, setting this variable
4600 lets GDB use hardware breakpoints automatically for memory regions
4601 where it can not use software breakpoints. This covers both the
4602 "break" command and internal breakpoints used for other commands
4603 including "next" and "finish".
4606 catch exception unhandled
4607 Stop the program execution when Ada exceptions are raised.
4610 Stop the program execution when an Ada assertion failed.
4614 Set an alternate system root for target files. This is a more
4615 general version of "set solib-absolute-prefix", which is now
4616 an alias to "set sysroot".
4619 Provide extended SPU facility status information. This set of
4620 commands is available only when debugging the Cell/B.E. SPU
4623 * New native configurations
4625 OpenBSD/sh sh*-*openbsd*
4628 unset tdesc filename
4630 Use the specified local file as an XML target description, and do
4631 not query the target for its built-in description.
4635 OpenBSD/sh sh*-*-openbsd*
4636 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4637 Toshiba Media Processor mep-elf
4639 * New remote packets
4642 Ignore the specified signals; pass them directly to the debugged program
4643 without stopping other threads or reporting them to GDB.
4645 qXfer:features:read:
4646 Read an XML target description from the target, which describes its
4651 Read or write contents of an spufs file on the target system. These
4652 packets are available only on the Cell/B.E. SPU architecture.
4654 qXfer:libraries:read:
4655 Report the loaded shared libraries. Combined with new "T" packet
4656 response, this packet allows GDB to debug shared libraries on
4657 targets where the operating system manages the list of loaded
4658 libraries (e.g. Windows and SymbianOS).
4662 Support for these obsolete configurations has been removed.
4670 i[34567]86-*-lynxos*
4671 i[34567]86-*-netware*
4672 i[34567]86-*-sco3.2v5*
4673 i[34567]86-*-sco3.2v4*
4675 i[34567]86-*-sysv4.2*
4678 i[34567]86-*-unixware2*
4679 i[34567]86-*-unixware*
4688 * Other removed features
4695 Various m68k-only ROM monitors.
4702 Various Renesas ROM monitors and debugging interfaces for SH and
4707 Support for a Macraigor serial interface to on-chip debugging.
4708 GDB does not directly support the newer parallel or USB
4713 A debug information format. The predecessor to DWARF 2 and
4714 DWARF 3, which are still supported.
4716 Support for the HP aCC compiler on HP-UX/PA-RISC
4718 SOM-encapsulated symbolic debugging information, automatic
4719 invocation of pxdb, and the aCC custom C++ ABI. This does not
4720 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4721 with aCC can still be debugged on an assembly level.
4723 MIPS ".pdr" sections
4725 A MIPS-specific format used to describe stack frame layout
4726 in debugging information.
4730 GDB could work with an older version of Guile to debug
4731 the interpreter and Scheme programs running in it.
4733 set mips stack-arg-size
4734 set mips saved-gpreg-size
4736 Use "set mips abi" to control parameter passing for MIPS.
4738 *** Changes in GDB 6.6
4743 Cell Broadband Engine SPU spu-elf
4745 * GDB can now be configured as a cross-debugger targeting native Windows
4746 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4747 running on a Windows system over TCP/IP to debug Windows programs.
4749 * The GDB remote stub, gdbserver, has been updated to support Windows and
4750 Cygwin debugging. Both single-threaded and multi-threaded programs are
4753 * The "set trust-readonly-sections" command works again. This command was
4754 broken in GDB 6.3, 6.4, and 6.5.
4756 * The "load" command now supports writing to flash memory, if the remote
4757 stub provides the required support.
4759 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4760 longer requires symbolic debug information (e.g. DWARF-2).
4765 unset substitute-path
4766 show substitute-path
4767 Manage a list of substitution rules that GDB uses to rewrite the name
4768 of the directories where the sources are located. This can be useful
4769 for instance when the sources were moved to a different location
4770 between compilation and debugging.
4774 Print each CLI command as it is executed. Each command is prefixed with
4775 a number of `+' symbols representing the nesting depth.
4776 The source command now has a `-v' option to enable the same feature.
4780 The ARM Demon monitor support (RDP protocol, "target rdp").
4782 Kernel Object Display, an embedded debugging feature which only worked with
4783 an obsolete version of Cisco IOS.
4785 The 'set download-write-size' and 'show download-write-size' commands.
4787 * New remote packets
4790 Tell a stub about GDB client features, and request remote target features.
4791 The first feature implemented is PacketSize, which allows the target to
4792 specify the size of packets it can handle - to minimize the number of
4793 packets required and improve performance when connected to a remote
4797 Fetch an OS auxilliary vector from the remote stub. This packet is a
4798 more efficient replacement for qPart:auxv:read.
4800 qXfer:memory-map:read:
4801 Fetch a memory map from the remote stub, including information about
4802 RAM, ROM, and flash memory devices.
4807 Erase and program a flash memory device.
4809 * Removed remote packets
4812 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4813 used it, and only gdbserver implemented it.
4815 *** Changes in GDB 6.5
4819 Renesas M32C/M16C m32c-elf
4821 Morpho Technologies ms1 ms1-elf
4825 init-if-undefined Initialize a convenience variable, but
4826 only if it doesn't already have a value.
4828 The following commands are presently only implemented for native GNU/Linux:
4830 checkpoint Save a snapshot of the program state.
4832 restart <n> Return the program state to a
4833 previously saved state.
4835 info checkpoints List currently saved checkpoints.
4837 delete-checkpoint <n> Delete a previously saved checkpoint.
4839 set|show detach-on-fork Tell gdb whether to detach from a newly
4840 forked process, or to keep debugging it.
4842 info forks List forks of the user program that
4843 are available to be debugged.
4845 fork <n> Switch to debugging one of several
4846 forks of the user program that are
4847 available to be debugged.
4849 delete-fork <n> Delete a fork from the list of forks
4850 that are available to be debugged (and
4851 kill the forked process).
4853 detach-fork <n> Delete a fork from the list of forks
4854 that are available to be debugged (and
4855 allow the process to continue).
4859 Morpho Technologies ms2 ms1-elf
4861 * Improved Windows host support
4863 GDB now builds as a cross debugger hosted on i686-mingw32, including
4864 native console support, and remote communications using either
4865 network sockets or serial ports.
4867 * Improved Modula-2 language support
4869 GDB can now print most types in the Modula-2 syntax. This includes:
4870 basic types, set types, record types, enumerated types, range types,
4871 pointer types and ARRAY types. Procedure var parameters are correctly
4872 printed and hexadecimal addresses and character constants are also
4873 written in the Modula-2 syntax. Best results can be obtained by using
4874 GNU Modula-2 together with the -gdwarf-2 command line option.
4878 The ARM rdi-share module.
4880 The Netware NLM debug server.
4882 *** Changes in GDB 6.4
4884 * New native configurations
4886 OpenBSD/arm arm*-*-openbsd*
4887 OpenBSD/mips64 mips64-*-openbsd*
4891 Morpho Technologies ms1 ms1-elf
4893 * New command line options
4895 --batch-silent As for --batch, but totally silent.
4896 --return-child-result The debugger will exist with the same value
4897 the child (debugged) program exited with.
4898 --eval-command COMMAND, -ex COMMAND
4899 Execute a single GDB CLI command. This may be
4900 specified multiple times and in conjunction
4901 with the --command (-x) option.
4903 * Deprecated commands removed
4905 The following commands, that were deprecated in 2000, have been
4909 set|show arm disassembly-flavor set|show arm disassembler
4910 othernames set arm disassembler
4911 set|show remotedebug set|show debug remote
4912 set|show archdebug set|show debug arch
4913 set|show eventdebug set|show debug event
4916 * New BSD user-level threads support
4918 It is now possible to debug programs using the user-level threads
4919 library on OpenBSD and FreeBSD. Currently supported (target)
4922 FreeBSD/amd64 x86_64-*-freebsd*
4923 FreeBSD/i386 i386-*-freebsd*
4924 OpenBSD/i386 i386-*-openbsd*
4926 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4927 are not yet supported.
4929 * New support for Matsushita MN10300 w/sim added
4930 (Work in progress). mn10300-elf.
4932 * REMOVED configurations and files
4934 VxWorks and the XDR protocol *-*-vxworks
4935 Motorola MCORE mcore-*-*
4936 National Semiconductor NS32000 ns32k-*-*
4938 * New "set print array-indexes" command
4940 After turning this setting "on", GDB prints the index of each element
4941 when displaying arrays. The default is "off" to preserve the previous
4944 * VAX floating point support
4946 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4948 * User-defined command support
4950 In addition to using $arg0..$arg9 for argument passing, it is now possible
4951 to use $argc to determine now many arguments have been passed. See the
4952 section on user-defined commands in the user manual for more information.
4954 *** Changes in GDB 6.3:
4956 * New command line option
4958 GDB now accepts -l followed by a number to set the timeout for remote
4961 * GDB works with GCC -feliminate-dwarf2-dups
4963 GDB now supports a more compact representation of DWARF-2 debug
4964 information using DW_FORM_ref_addr references. These are produced
4965 by GCC with the option -feliminate-dwarf2-dups and also by some
4966 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4967 to use -feliminate-dwarf2-dups.
4969 * Internationalization
4971 When supported by the host system, GDB will be built with
4972 internationalization (libintl). The task of marking up the sources is
4973 continued, we're looking forward to our first translation.
4977 Initial support for debugging programs compiled with the GNAT
4978 implementation of the Ada programming language has been integrated
4979 into GDB. In this release, support is limited to expression evaluation.
4981 * New native configurations
4983 GNU/Linux/m32r m32r-*-linux-gnu
4987 GDB's remote protocol now includes support for the 'p' packet. This
4988 packet is used to fetch individual registers from a remote inferior.
4990 * END-OF-LIFE registers[] compatibility module
4992 GDB's internal register infrastructure has been completely rewritten.
4993 The new infrastructure making possible the implementation of key new
4994 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4997 GDB 6.3 will be the last release to include the the registers[]
4998 compatibility module that allowed out-of-date configurations to
4999 continue to work. This change directly impacts the following
5009 powerpc bdm protocol
5011 Unless there is activity to revive these configurations, they will be
5012 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5014 * OBSOLETE configurations and files
5016 Configurations that have been declared obsolete in this release have
5017 been commented out. Unless there is activity to revive these
5018 configurations, the next release of GDB will have their sources
5019 permanently REMOVED.
5028 *** Changes in GDB 6.2.1:
5030 * MIPS `break main; run' gave an heuristic-fence-post warning
5032 When attempting to run even a simple program, a warning about
5033 heuristic-fence-post being hit would be reported. This problem has
5036 * MIPS IRIX 'long double' crashed GDB
5038 When examining a long double variable, GDB would get a segmentation
5039 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5040 IRIX long double values).
5044 A bug in the VAX stack code was causing problems with the "next"
5045 command. This problem has been fixed.
5047 *** Changes in GDB 6.2:
5049 * Fix for ``many threads''
5051 On GNU/Linux systems that use the NPTL threads library, a program
5052 rapidly creating and deleting threads would confuse GDB leading to the
5055 ptrace: No such process.
5056 thread_db_get_info: cannot get thread info: generic error
5058 This problem has been fixed.
5060 * "-async" and "-noasync" options removed.
5062 Support for the broken "-noasync" option has been removed (it caused
5065 * New ``start'' command.
5067 This command runs the program until the begining of the main procedure.
5069 * New BSD Kernel Data Access Library (libkvm) interface
5071 Using ``target kvm'' it is now possible to debug kernel core dumps and
5072 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5073 platforms. Currently supported (native-only) configurations are:
5075 FreeBSD/amd64 x86_64-*-freebsd*
5076 FreeBSD/i386 i?86-*-freebsd*
5077 NetBSD/i386 i?86-*-netbsd*
5078 NetBSD/m68k m68*-*-netbsd*
5079 NetBSD/sparc sparc-*-netbsd*
5080 OpenBSD/amd64 x86_64-*-openbsd*
5081 OpenBSD/i386 i?86-*-openbsd*
5082 OpenBSD/m68k m68*-openbsd*
5083 OpenBSD/sparc sparc-*-openbsd*
5085 * Signal trampoline code overhauled
5087 Many generic problems with GDB's signal handling code have been fixed.
5088 These include: backtraces through non-contiguous stacks; recognition
5089 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5090 call; backtrace through a signal trampoline; step into and out of
5091 signal handlers; and single-stepping in the signal trampoline.
5093 Please note that kernel bugs are a limiting factor here. These
5094 features have been shown to work on an s390 GNU/Linux system that
5095 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5097 * Cygwin support for DWARF 2 added.
5099 * New native configurations
5101 GNU/Linux/hppa hppa*-*-linux*
5102 OpenBSD/hppa hppa*-*-openbsd*
5103 OpenBSD/m68k m68*-*-openbsd*
5104 OpenBSD/m88k m88*-*-openbsd*
5105 OpenBSD/powerpc powerpc-*-openbsd*
5106 NetBSD/vax vax-*-netbsd*
5107 OpenBSD/vax vax-*-openbsd*
5109 * END-OF-LIFE frame compatibility module
5111 GDB's internal frame infrastructure has been completely rewritten.
5112 The new infrastructure making it possible to support key new features
5113 including DWARF 2 Call Frame Information. To aid in the task of
5114 migrating old configurations to this new infrastructure, a
5115 compatibility module, that allowed old configurations to continue to
5116 work, was also included.
5118 GDB 6.2 will be the last release to include this frame compatibility
5119 module. This change directly impacts the following configurations:
5129 Unless there is activity to revive these configurations, they will be
5130 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5132 * REMOVED configurations and files
5134 Sun 3, running SunOS 3 m68*-*-sunos3*
5135 Sun 3, running SunOS 4 m68*-*-sunos4*
5136 Sun 2, running SunOS 3 m68000-*-sunos3*
5137 Sun 2, running SunOS 4 m68000-*-sunos4*
5138 Motorola 680x0 running LynxOS m68*-*-lynxos*
5139 AT&T 3b1/Unix pc m68*-att-*
5140 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5141 decstation mips-dec-* mips-little-*
5142 riscos mips-*-riscos* mips-*-sysv*
5143 sonymips mips-sony-*
5144 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5146 *** Changes in GDB 6.1.1:
5148 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5150 The TUI (Text-mode User Interface) is now built as part of a default
5151 GDB configuration. It is enabled by either selecting the TUI with the
5152 command line option "-i=tui" or by running the separate "gdbtui"
5153 program. For more information on the TUI, see the manual "Debugging
5156 * Pending breakpoint support (also included in GDB 6.1)
5158 Support has been added to allow you to specify breakpoints in shared
5159 libraries that have not yet been loaded. If a breakpoint location
5160 cannot be found, and the "breakpoint pending" option is set to auto,
5161 GDB queries you if you wish to make the breakpoint pending on a future
5162 shared-library load. If and when GDB resolves the breakpoint symbol,
5163 the pending breakpoint is removed as one or more regular breakpoints
5166 Pending breakpoints are very useful for GCJ Java debugging.
5168 * Fixed ISO-C build problems
5170 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5171 non ISO-C code that stopped them being built using a more strict ISO-C
5172 compiler (e.g., IBM's C compiler).
5174 * Fixed build problem on IRIX 5
5176 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5177 wasn't able to compile compile on an IRIX 5 system.
5179 * Added execute permission to gdb/gdbserver/configure
5181 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5182 permission. This bug would cause configure to fail on a number of
5183 systems (Solaris, IRIX). Ref: server/519.
5185 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5187 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5188 has been updated to use constant array sizes.
5190 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5192 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5193 its generated DWARF Call Frame Info. This encoding was causing GDB to
5194 panic, that panic has been fixed. Ref: gdb/1628.
5196 * Fixed a problem when examining parameters in shared library code.
5198 When examining parameters in optimized shared library code generated
5199 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5200 not available''. GDB now correctly displays the variable's value.
5202 *** Changes in GDB 6.1:
5204 * Removed --with-mmalloc
5206 Support for the mmalloc memory manager has been removed, as it
5207 conflicted with the internal gdb byte cache.
5209 * Changes in AMD64 configurations
5211 The AMD64 target now includes the %cs and %ss registers. As a result
5212 the AMD64 remote protocol has changed; this affects the floating-point
5213 and SSE registers. If you rely on those registers for your debugging,
5214 you should upgrade gdbserver on the remote side.
5216 * Revised SPARC target
5218 The SPARC target has been completely revised, incorporating the
5219 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5220 support for LynxOS and SunOS 4 has been dropped. Calling functions
5221 from within GDB on operating systems with a non-executable stack
5222 (Solaris, OpenBSD) now works.
5226 GDB has a new C++ demangler which does a better job on the mangled
5227 names generated by current versions of g++. It also runs faster, so
5228 with this and other changes gdb should now start faster on large C++
5231 * DWARF 2 Location Expressions
5233 GDB support for location expressions has been extended to support function
5234 arguments and frame bases. Older versions of GDB could crash when they
5237 * C++ nested types and namespaces
5239 GDB's support for nested types and namespaces in C++ has been
5240 improved, especially if you use the DWARF 2 debugging format. (This
5241 is the default for recent versions of GCC on most platforms.)
5242 Specifically, if you have a class "Inner" defined within a class or
5243 namespace "Outer", then GDB realizes that the class's name is
5244 "Outer::Inner", not simply "Inner". This should greatly reduce the
5245 frequency of complaints about not finding RTTI symbols. In addition,
5246 if you are stopped at inside of a function defined within a namespace,
5247 GDB modifies its name lookup accordingly.
5249 * New native configurations
5251 NetBSD/amd64 x86_64-*-netbsd*
5252 OpenBSD/amd64 x86_64-*-openbsd*
5253 OpenBSD/alpha alpha*-*-openbsd*
5254 OpenBSD/sparc sparc-*-openbsd*
5255 OpenBSD/sparc64 sparc64-*-openbsd*
5257 * New debugging protocols
5259 M32R with SDI protocol m32r-*-elf*
5261 * "set prompt-escape-char" command deleted.
5263 The command "set prompt-escape-char" has been deleted. This command,
5264 and its very obscure effet on GDB's prompt, was never documented,
5265 tested, nor mentioned in the NEWS file.
5267 * OBSOLETE configurations and files
5269 Configurations that have been declared obsolete in this release have
5270 been commented out. Unless there is activity to revive these
5271 configurations, the next release of GDB will have their sources
5272 permanently REMOVED.
5274 Sun 3, running SunOS 3 m68*-*-sunos3*
5275 Sun 3, running SunOS 4 m68*-*-sunos4*
5276 Sun 2, running SunOS 3 m68000-*-sunos3*
5277 Sun 2, running SunOS 4 m68000-*-sunos4*
5278 Motorola 680x0 running LynxOS m68*-*-lynxos*
5279 AT&T 3b1/Unix pc m68*-att-*
5280 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5281 decstation mips-dec-* mips-little-*
5282 riscos mips-*-riscos* mips-*-sysv*
5283 sonymips mips-sony-*
5284 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5286 * REMOVED configurations and files
5288 SGI Irix-4.x mips-sgi-irix4 or iris4
5289 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5290 Z8000 simulator z8k-zilog-none or z8ksim
5291 Matsushita MN10200 w/simulator mn10200-*-*
5292 H8/500 simulator h8500-hitachi-hms or h8500hms
5293 HP/PA running BSD hppa*-*-bsd*
5294 HP/PA running OSF/1 hppa*-*-osf*
5295 HP/PA Pro target hppa*-*-pro*
5296 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5297 386BSD i[3456]86-*-bsd*
5298 Sequent family i[3456]86-sequent-sysv4*
5299 i[3456]86-sequent-sysv*
5300 i[3456]86-sequent-bsd*
5301 SPARC running LynxOS sparc-*-lynxos*
5302 SPARC running SunOS 4 sparc-*-sunos4*
5303 Tsqware Sparclet sparclet-*-*
5304 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5306 *** Changes in GDB 6.0:
5310 Support for debugging the Objective-C programming language has been
5311 integrated into GDB.
5313 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5315 DWARF 2's Call Frame Information makes available compiler generated
5316 information that more exactly describes the program's run-time stack.
5317 By using this information, GDB is able to provide more robust stack
5320 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5321 have been updated to use a new backtrace mechanism which includes
5322 DWARF 2 CFI support.
5326 GDB's remote protocol has been extended to include support for hosted
5327 file I/O (where the remote target uses GDB's file system). See GDB's
5328 remote protocol documentation for details.
5330 * All targets using the new architecture framework.
5332 All of GDB's targets have been updated to use the new internal
5333 architecture framework. The way is now open for future GDB releases
5334 to include cross-architecture native debugging support (i386 on amd64,
5337 * GNU/Linux's Thread Local Storage (TLS)
5339 GDB now includes support for for the GNU/Linux implementation of
5340 per-thread variables.
5342 * GNU/Linux's Native POSIX Thread Library (NPTL)
5344 GDB's thread code has been updated to work with either the new
5345 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5347 * Separate debug info.
5349 GDB, in conjunction with BINUTILS, now supports a mechanism for
5350 automatically loading debug information from a separate file. Instead
5351 of shipping full debug and non-debug versions of system libraries,
5352 system integrators can now instead ship just the stripped libraries
5353 and optional debug files.
5355 * DWARF 2 Location Expressions
5357 DWARF 2 Location Expressions allow the compiler to more completely
5358 describe the location of variables (even in optimized code) to the
5361 GDB now includes preliminary support for location expressions (support
5362 for DW_OP_piece is still missing).
5366 A number of long standing bugs that caused GDB to die while starting a
5367 Java application have been fixed. GDB's Java support is now
5368 considered "useable".
5370 * GNU/Linux support for fork, vfork, and exec.
5372 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5373 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5376 * GDB supports logging output to a file
5378 There are two new commands, "set logging" and "show logging", which can be
5379 used to capture GDB's output to a file.
5381 * The meaning of "detach" has changed for gdbserver
5383 The "detach" command will now resume the application, as documented. To
5384 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5387 * d10v, m68hc11 `regs' command deprecated
5389 The `info registers' command has been updated so that it displays the
5390 registers using a format identical to the old `regs' command.
5394 A new command, "maint set profile on/off", has been added. This command can
5395 be used to enable or disable profiling while running GDB, to profile a
5396 session or a set of commands. In addition there is a new configure switch,
5397 "--enable-profiling", which will cause GDB to be compiled with profiling
5398 data, for more informative profiling results.
5400 * Default MI syntax changed to "mi2".
5402 The default MI (machine interface) syntax, enabled by the command line
5403 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5404 "mi1", can be enabled by specifying the option "-i=mi1".
5406 Support for the original "mi0" syntax (included in GDB 5.0) has been
5409 Fix for gdb/192: removed extraneous space when displaying frame level.
5410 Fix for gdb/672: update changelist is now output in mi list format.
5411 Fix for gdb/702: a -var-assign that updates the value now shows up
5412 in a subsequent -var-update.
5414 * New native configurations.
5416 FreeBSD/amd64 x86_64-*-freebsd*
5418 * Multi-arched targets.
5420 HP/PA HPUX11 hppa*-*-hpux*
5421 Renesas M32R/D w/simulator m32r-*-elf*
5423 * OBSOLETE configurations and files
5425 Configurations that have been declared obsolete in this release have
5426 been commented out. Unless there is activity to revive these
5427 configurations, the next release of GDB will have their sources
5428 permanently REMOVED.
5430 Z8000 simulator z8k-zilog-none or z8ksim
5431 Matsushita MN10200 w/simulator mn10200-*-*
5432 H8/500 simulator h8500-hitachi-hms or h8500hms
5433 HP/PA running BSD hppa*-*-bsd*
5434 HP/PA running OSF/1 hppa*-*-osf*
5435 HP/PA Pro target hppa*-*-pro*
5436 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5437 Sequent family i[3456]86-sequent-sysv4*
5438 i[3456]86-sequent-sysv*
5439 i[3456]86-sequent-bsd*
5440 Tsqware Sparclet sparclet-*-*
5441 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5443 * REMOVED configurations and files
5446 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5447 IBM AIX PS/2 i[3456]86-*-aix
5448 i386 running Mach 3.0 i[3456]86-*-mach3*
5449 i386 running Mach i[3456]86-*-mach*
5450 i386 running OSF/1 i[3456]86-*osf1mk*
5451 HP/Apollo 68k Family m68*-apollo*-sysv*,
5453 m68*-hp-bsd*, m68*-hp-hpux*
5454 Argonaut Risc Chip (ARC) arc-*-*
5455 Mitsubishi D30V d30v-*-*
5456 Fujitsu FR30 fr30-*-elf*
5457 OS/9000 i[34]86-*-os9k
5458 I960 with MON960 i960-*-coff
5460 * MIPS $fp behavior changed
5462 The convenience variable $fp, for the MIPS, now consistently returns
5463 the address of the current frame's base. Previously, depending on the
5464 context, $fp could refer to either $sp or the current frame's base
5465 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5466 The GNU Source-Level Debugger''.
5468 *** Changes in GDB 5.3:
5470 * GNU/Linux shared library multi-threaded performance improved.
5472 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5473 `/proc', in preference to `ptrace' for memory reads. This may result
5474 in an improvement in the start-up time of multi-threaded, shared
5475 library applications when run under GDB. One GDB user writes: ``loads
5476 shared libs like mad''.
5478 * ``gdbserver'' now supports multi-threaded applications on some targets
5480 Support for debugging multi-threaded applications which use
5481 the GNU/Linux LinuxThreads package has been added for
5482 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5483 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5485 * GDB now supports C/C++ preprocessor macros.
5487 GDB now expands preprocessor macro invocations in C/C++ expressions,
5488 and provides various commands for showing macro definitions and how
5491 The new command `macro expand EXPRESSION' expands any macro
5492 invocations in expression, and shows the result.
5494 The new command `show macro MACRO-NAME' shows the definition of the
5495 macro named MACRO-NAME, and where it was defined.
5497 Most compilers don't include information about macros in the debugging
5498 information by default. In GCC 3.1, for example, you need to compile
5499 your program with the options `-gdwarf-2 -g3'. If the macro
5500 information is present in the executable, GDB will read it.
5502 * Multi-arched targets.
5504 DEC Alpha (partial) alpha*-*-*
5505 DEC VAX (partial) vax-*-*
5507 National Semiconductor NS32000 (partial) ns32k-*-*
5508 Motorola 68000 (partial) m68k-*-*
5509 Motorola MCORE mcore-*-*
5513 Fujitsu FRV architecture added by Red Hat frv*-*-*
5516 * New native configurations
5518 Alpha NetBSD alpha*-*-netbsd*
5519 SH NetBSD sh*-*-netbsdelf*
5520 MIPS NetBSD mips*-*-netbsd*
5521 UltraSPARC NetBSD sparc64-*-netbsd*
5523 * OBSOLETE configurations and files
5525 Configurations that have been declared obsolete in this release have
5526 been commented out. Unless there is activity to revive these
5527 configurations, the next release of GDB will have their sources
5528 permanently REMOVED.
5530 Mitsubishi D30V d30v-*-*
5531 OS/9000 i[34]86-*-os9k
5532 IBM AIX PS/2 i[3456]86-*-aix
5533 Fujitsu FR30 fr30-*-elf*
5534 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5535 Argonaut Risc Chip (ARC) arc-*-*
5536 i386 running Mach 3.0 i[3456]86-*-mach3*
5537 i386 running Mach i[3456]86-*-mach*
5538 i386 running OSF/1 i[3456]86-*osf1mk*
5539 HP/Apollo 68k Family m68*-apollo*-sysv*,
5541 m68*-hp-bsd*, m68*-hp-hpux*
5542 I960 with MON960 i960-*-coff
5544 * OBSOLETE languages
5546 CHILL, a Pascal like language used by telecommunications companies.
5548 * REMOVED configurations and files
5550 AMD 29k family via UDI a29k-amd-udi, udi29k
5551 A29K VxWorks a29k-*-vxworks
5552 AMD 29000 embedded, using EBMON a29k-none-none
5553 AMD 29000 embedded with COFF a29k-none-coff
5554 AMD 29000 embedded with a.out a29k-none-aout
5556 testsuite/gdb.hp/gdb.threads-hp/ directory
5558 * New command "set max-user-call-depth <nnn>"
5560 This command allows the user to limit the call depth of user-defined
5561 commands. The default is 1024.
5563 * Changes in FreeBSD/i386 native debugging.
5565 Support for the "generate-core-file" has been added.
5567 * New commands "dump", "append", and "restore".
5569 These commands allow data to be copied from target memory
5570 to a bfd-format or binary file (dump and append), and back
5571 from a file into memory (restore).
5573 * Improved "next/step" support on multi-processor Alpha Tru64.
5575 The previous single-step mechanism could cause unpredictable problems,
5576 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5577 of a software single-step mechanism prevents this.
5579 *** Changes in GDB 5.2.1:
5587 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5588 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5589 Fix, by Joel Brobecker imported from mainline.
5591 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5592 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5593 Fix, by Fred Fish, imported from mainline.
5595 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5596 Surprisingly enough, it works now.
5597 By Michal Ludvig, imported from mainline.
5599 i386 hardware watchpoint support:
5600 avoid misses on second run for some targets.
5601 By Pierre Muller, imported from mainline.
5603 *** Changes in GDB 5.2:
5605 * New command "set trust-readonly-sections on[off]".
5607 This command is a hint that tells gdb that read-only sections
5608 really are read-only (ie. that their contents will not change).
5609 In this mode, gdb will go to the object file rather than the
5610 target to read memory from read-only sections (such as ".text").
5611 This can be a significant performance improvement on some
5612 (notably embedded) targets.
5614 * New command "generate-core-file" (or "gcore").
5616 This new gdb command allows the user to drop a core file of the child
5617 process state at any time. So far it's been implemented only for
5618 GNU/Linux and Solaris, but should be relatively easily ported to other
5619 hosts. Argument is core file name (defaults to core.<pid>).
5621 * New command line option
5623 GDB now accepts --pid or -p followed by a process id.
5625 * Change in command line behavior -- corefiles vs. process ids.
5627 There is a subtle behavior in the way in which GDB handles
5628 command line arguments. The first non-flag argument is always
5629 a program to debug, but the second non-flag argument may either
5630 be a corefile or a process id. Previously, GDB would attempt to
5631 open the second argument as a corefile, and if that failed, would
5632 issue a superfluous error message and then attempt to attach it as
5633 a process. Now, if the second argument begins with a non-digit,
5634 it will be treated as a corefile. If it begins with a digit,
5635 GDB will attempt to attach it as a process, and if no such process
5636 is found, will then attempt to open it as a corefile.
5638 * Changes in ARM configurations.
5640 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5641 configuration is fully multi-arch.
5643 * New native configurations
5645 ARM NetBSD arm*-*-netbsd*
5646 x86 OpenBSD i[3456]86-*-openbsd*
5647 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5648 Sparc64 running FreeBSD sparc64-*-freebsd*
5652 Sanyo XStormy16 xstormy16-elf
5654 * OBSOLETE configurations and files
5656 Configurations that have been declared obsolete in this release have
5657 been commented out. Unless there is activity to revive these
5658 configurations, the next release of GDB will have their sources
5659 permanently REMOVED.
5661 AMD 29k family via UDI a29k-amd-udi, udi29k
5662 A29K VxWorks a29k-*-vxworks
5663 AMD 29000 embedded, using EBMON a29k-none-none
5664 AMD 29000 embedded with COFF a29k-none-coff
5665 AMD 29000 embedded with a.out a29k-none-aout
5667 testsuite/gdb.hp/gdb.threads-hp/ directory
5669 * REMOVED configurations and files
5671 TI TMS320C80 tic80-*-*
5673 PowerPC Solaris powerpcle-*-solaris*
5674 PowerPC Windows NT powerpcle-*-cygwin32
5675 PowerPC Netware powerpc-*-netware*
5676 Harris/CXUX m88k m88*-harris-cxux*
5677 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5678 ns32k-utek-sysv* ns32k-utek-*
5679 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5680 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5681 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5682 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5683 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5685 * Changes to command line processing
5687 The new `--args' feature can be used to specify command-line arguments
5688 for the inferior from gdb's command line.
5690 * Changes to key bindings
5692 There is a new `operate-and-get-next' function bound to `C-o'.
5694 *** Changes in GDB 5.1.1
5696 Fix compile problem on DJGPP.
5698 Fix a problem with floating-point registers on the i386 being
5701 Fix to stop GDB crashing on .debug_str debug info.
5703 Numerous documentation fixes.
5705 Numerous testsuite fixes.
5707 *** Changes in GDB 5.1:
5709 * New native configurations
5711 Alpha FreeBSD alpha*-*-freebsd*
5712 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5713 MIPS GNU/Linux mips*-*-linux*
5714 MIPS SGI Irix 6.x mips*-sgi-irix6*
5715 ia64 AIX ia64-*-aix*
5716 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5720 Motorola 68HC11 and 68HC12 m68hc11-elf
5722 UltraSparc running GNU/Linux sparc64-*-linux*
5724 * OBSOLETE configurations and files
5726 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5727 Harris/CXUX m88k m88*-harris-cxux*
5728 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5729 ns32k-utek-sysv* ns32k-utek-*
5730 TI TMS320C80 tic80-*-*
5732 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5733 PowerPC Solaris powerpcle-*-solaris*
5734 PowerPC Windows NT powerpcle-*-cygwin32
5735 PowerPC Netware powerpc-*-netware*
5736 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5737 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5738 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5739 Apple Macintosh (MPW) host N/A
5741 stuff.c (Program to stuff files into a specially prepared space in kdb)
5742 kdb-start.c (Main loop for the standalone kernel debugger)
5744 Configurations that have been declared obsolete in this release have
5745 been commented out. Unless there is activity to revive these
5746 configurations, the next release of GDB will have their sources
5747 permanently REMOVED.
5749 * REMOVED configurations and files
5751 Altos 3068 m68*-altos-*
5752 Convex c1-*-*, c2-*-*
5754 ARM RISCix arm-*-* (as host)
5758 * GDB has been converted to ISO C.
5760 GDB's source code has been converted to ISO C. In particular, the
5761 sources are fully protoized, and rely on standard headers being
5766 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5768 * The MI enabled by default.
5770 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5771 revised and enabled by default. Packages which use GDB as a debugging
5772 engine behind a UI or another front end are encouraged to switch to
5773 using the GDB/MI interface, instead of the old annotations interface
5774 which is now deprecated.
5776 * Support for debugging Pascal programs.
5778 GDB now includes support for debugging Pascal programs. The following
5779 main features are supported:
5781 - Pascal-specific data types such as sets;
5783 - automatic recognition of Pascal sources based on file-name
5786 - Pascal-style display of data types, variables, and functions;
5788 - a Pascal expression parser.
5790 However, some important features are not yet supported.
5792 - Pascal string operations are not supported at all;
5794 - there are some problems with boolean types;
5796 - Pascal type hexadecimal constants are not supported
5797 because they conflict with the internal variables format;
5799 - support for Pascal objects and classes is not full yet;
5801 - unlike Pascal, GDB is case-sensitive for symbol names.
5803 * Changes in completion.
5805 Commands such as `shell', `run' and `set args', which pass arguments
5806 to inferior programs, now complete on file names, similar to what
5807 users expect at the shell prompt.
5809 Commands which accept locations, such as `disassemble', `print',
5810 `breakpoint', `until', etc. now complete on filenames as well as
5811 program symbols. Thus, if you type "break foob TAB", and the source
5812 files linked into the programs include `foobar.c', that file name will
5813 be one of the candidates for completion. However, file names are not
5814 considered for completion after you typed a colon that delimits a file
5815 name from a name of a function in that file, as in "break foo.c:bar".
5817 `set demangle-style' completes on available demangling styles.
5819 * New platform-independent commands:
5821 It is now possible to define a post-hook for a command as well as a
5822 hook that runs before the command. For more details, see the
5823 documentation of `hookpost' in the GDB manual.
5825 * Changes in GNU/Linux native debugging.
5827 Support for debugging multi-threaded programs has been completely
5828 revised for all platforms except m68k and sparc. You can now debug as
5829 many threads as your system allows you to have.
5831 Attach/detach is supported for multi-threaded programs.
5833 Support for SSE registers was added for x86. This doesn't work for
5834 multi-threaded programs though.
5836 * Changes in MIPS configurations.
5838 Multi-arch support is enabled for all MIPS configurations.
5840 GDB can now be built as native debugger on SGI Irix 6.x systems for
5841 debugging n32 executables. (Debugging 64-bit executables is not yet
5844 * Unified support for hardware watchpoints in all x86 configurations.
5846 Most (if not all) native x86 configurations support hardware-assisted
5847 breakpoints and watchpoints in a unified manner. This support
5848 implements debug register sharing between watchpoints, which allows to
5849 put a virtually infinite number of watchpoints on the same address,
5850 and also supports watching regions up to 16 bytes with several debug
5853 The new maintenance command `maintenance show-debug-regs' toggles
5854 debugging print-outs in functions that insert, remove, and test
5855 watchpoints and hardware breakpoints.
5857 * Changes in the DJGPP native configuration.
5859 New command ``info dos sysinfo'' displays assorted information about
5860 the CPU, OS, memory, and DPMI server.
5862 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5863 display information about segment descriptors stored in GDT, LDT, and
5866 New commands ``info dos pde'' and ``info dos pte'' display entries
5867 from Page Directory and Page Tables (for now works with CWSDPMI only).
5868 New command ``info dos address-pte'' displays the Page Table entry for
5869 a given linear address.
5871 GDB can now pass command lines longer than 126 characters to the
5872 program being debugged (requires an update to the libdbg.a library
5873 which is part of the DJGPP development kit).
5875 DWARF2 debug info is now supported.
5877 It is now possible to `step' and `next' through calls to `longjmp'.
5879 * Changes in documentation.
5881 All GDB documentation was converted to GFDL, the GNU Free
5882 Documentation License.
5884 Tracepoints-related commands are now fully documented in the GDB
5887 TUI, the Text-mode User Interface, is now documented in the manual.
5889 Tracepoints-related commands are now fully documented in the GDB
5892 The "GDB Internals" manual now has an index. It also includes
5893 documentation of `ui_out' functions, GDB coding standards, x86
5894 hardware watchpoints, and memory region attributes.
5896 * GDB's version number moved to ``version.in''
5898 The Makefile variable VERSION has been replaced by the file
5899 ``version.in''. People creating GDB distributions should update the
5900 contents of this file.
5904 GUD support is now a standard part of the EMACS distribution.
5906 *** Changes in GDB 5.0:
5908 * Improved support for debugging FP programs on x86 targets
5910 Unified and much-improved support for debugging floating-point
5911 programs on all x86 targets. In particular, ``info float'' now
5912 displays the FP registers in the same format on all x86 targets, with
5913 greater level of detail.
5915 * Improvements and bugfixes in hardware-assisted watchpoints
5917 It is now possible to watch array elements, struct members, and
5918 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5919 on x86 targets no longer erroneously trigger when the address is
5922 * Improvements in the native DJGPP version of GDB
5924 The distribution now includes all the scripts and auxiliary files
5925 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5926 machines ``out of the box''.
5928 The DJGPP version can now debug programs that use signals. It is
5929 possible to catch signals that happened in the debuggee, deliver
5930 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5931 would kill the program being debugged.) Programs that hook hardware
5932 interrupts (keyboard, timer, etc.) can also be debugged.
5934 It is now possible to debug DJGPP programs that redirect their
5935 standard handles or switch them to raw (as opposed to cooked) mode, or
5936 even close them. The command ``run < foo > bar'' works as expected,
5937 and ``info terminal'' reports useful information about the debuggee's
5938 terminal, including raw/cooked mode, redirection, etc.
5940 The DJGPP version now uses termios functions for console I/O, which
5941 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5944 DOS-style file names with drive letters are now fully supported by
5947 It is now possible to debug DJGPP programs that switch their working
5948 directory. It is also possible to rerun the debuggee any number of
5949 times without restarting GDB; thus, you can use the same setup,
5950 breakpoints, etc. for many debugging sessions.
5952 * New native configurations
5954 ARM GNU/Linux arm*-*-linux*
5955 PowerPC GNU/Linux powerpc-*-linux*
5959 Motorola MCore mcore-*-*
5960 x86 VxWorks i[3456]86-*-vxworks*
5961 PowerPC VxWorks powerpc-*-vxworks*
5962 TI TMS320C80 tic80-*-*
5964 * OBSOLETE configurations
5966 Altos 3068 m68*-altos-*
5967 Convex c1-*-*, c2-*-*
5969 ARM RISCix arm-*-* (as host)
5972 Configurations that have been declared obsolete will be commented out,
5973 but the code will be left in place. If there is no activity to revive
5974 these configurations before the next release of GDB, the sources will
5975 be permanently REMOVED.
5977 * Gould support removed
5979 Support for the Gould PowerNode and NP1 has been removed.
5981 * New features for SVR4
5983 On SVR4 native platforms (such as Solaris), if you attach to a process
5984 without first loading a symbol file, GDB will now attempt to locate and
5985 load symbols from the running process's executable file.
5987 * Many C++ enhancements
5989 C++ support has been greatly improved. Overload resolution now works properly
5990 in almost all cases. RTTI support is on the way.
5992 * Remote targets can connect to a sub-program
5994 A popen(3) style serial-device has been added. This device starts a
5995 sub-process (such as a stand-alone simulator) and then communicates
5996 with that. The sub-program to run is specified using the syntax
5997 ``|<program> <args>'' vis:
5999 (gdb) set remotedebug 1
6000 (gdb) target extended-remote |mn10300-elf-sim program-args
6002 * MIPS 64 remote protocol
6004 A long standing bug in the mips64 remote protocol where by GDB
6005 expected certain 32 bit registers (ex SR) to be transfered as 32
6006 instead of 64 bits has been fixed.
6008 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6009 added to provide backward compatibility with older versions of GDB.
6011 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6013 The command ``set remotebinarydownload'' command has been replaced by
6014 ``set remote X-packet''. Other commands in ``set remote'' family
6015 include ``set remote P-packet''.
6017 * Breakpoint commands accept ranges.
6019 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6020 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6021 ``tracepoint passcount'' also accepts a range of tracepoints.
6023 * ``apropos'' command added.
6025 The ``apropos'' command searches through command names and
6026 documentation strings, printing out matches, making it much easier to
6027 try to find a command that does what you are looking for.
6031 A new machine oriented interface (MI) has been added to GDB. This
6032 interface is designed for debug environments running GDB as a separate
6033 process. This is part of the long term libGDB project. See the
6034 "GDB/MI" chapter of the GDB manual for further information. It can be
6035 enabled by configuring with:
6037 .../configure --enable-gdbmi
6039 *** Changes in GDB-4.18:
6041 * New native configurations
6043 HP-UX 10.20 hppa*-*-hpux10.20
6044 HP-UX 11.x hppa*-*-hpux11.0*
6045 M68K GNU/Linux m68*-*-linux*
6049 Fujitsu FR30 fr30-*-elf*
6050 Intel StrongARM strongarm-*-*
6051 Mitsubishi D30V d30v-*-*
6053 * OBSOLETE configurations
6055 Gould PowerNode, NP1 np1-*-*, pn-*-*
6057 Configurations that have been declared obsolete will be commented out,
6058 but the code will be left in place. If there is no activity to revive
6059 these configurations before the next release of GDB, the sources will
6060 be permanently REMOVED.
6064 As a compatibility experiment, GDB's source files buildsym.h and
6065 buildsym.c have been converted to pure standard C, no longer
6066 containing any K&R compatibility code. We believe that all systems in
6067 use today either come with a standard C compiler, or have a GCC port
6068 available. If this is not true, please report the affected
6069 configuration to bug-gdb@gnu.org immediately. See the README file for
6070 information about getting a standard C compiler if you don't have one
6075 GDB now uses readline 2.2.
6077 * set extension-language
6079 You can now control the mapping between filename extensions and source
6080 languages by using the `set extension-language' command. For instance,
6081 you can ask GDB to treat .c files as C++ by saying
6082 set extension-language .c c++
6083 The command `info extensions' lists all of the recognized extensions
6084 and their associated languages.
6086 * Setting processor type for PowerPC and RS/6000
6088 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6089 you can use the `set processor' command to specify what variant of the
6090 PowerPC family you are debugging. The command
6094 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6095 following PowerPC and RS6000 variants:
6097 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6098 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6100 403GC IBM PowerPC 403GC
6101 505 Motorola PowerPC 505
6102 860 Motorola PowerPC 860 or 850
6103 601 Motorola PowerPC 601
6104 602 Motorola PowerPC 602
6105 603 Motorola/IBM PowerPC 603 or 603e
6106 604 Motorola PowerPC 604 or 604e
6107 750 Motorola/IBM PowerPC 750 or 750
6109 At the moment, this command just tells GDB what to name the
6110 special-purpose processor registers. Since almost all the affected
6111 registers are inaccessible to user-level programs, this command is
6112 only useful for remote debugging in its present form.
6116 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6117 more extensive support for HP-UX. Added features include shared
6118 library support, kernel threads and hardware watchpoints for 11.00,
6119 support for HP's ANSI C and C++ compilers, and a compatibility mode
6120 for xdb and dbx commands.
6124 HP's donation includes the new concept of catchpoints, which is a
6125 generalization of the old catch command. On HP-UX, it is now possible
6126 to catch exec, fork, and vfork, as well as library loading.
6128 This means that the existing catch command has changed; its first
6129 argument now specifies the type of catch to be set up. See the
6130 output of "help catch" for a list of catchpoint types.
6132 * Debugging across forks
6134 On HP-UX, you can choose which process to debug when a fork() happens
6139 HP has donated a curses-based terminal user interface (TUI). To get
6140 it, build with --enable-tui. Although this can be enabled for any
6141 configuration, at present it only works for native HP debugging.
6143 * GDB remote protocol additions
6145 A new protocol packet 'X' that writes binary data is now available.
6146 Default behavior is to try 'X', then drop back to 'M' if the stub
6147 fails to respond. The settable variable `remotebinarydownload'
6148 allows explicit control over the use of 'X'.
6150 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6151 full 64-bit address. The command
6153 set remoteaddresssize 32
6155 can be used to revert to the old behaviour. For existing remote stubs
6156 the change should not be noticed, as the additional address information
6159 In order to assist in debugging stubs, you may use the maintenance
6160 command `packet' to send any text string to the stub. For instance,
6162 maint packet heythere
6164 sends the packet "$heythere#<checksum>". Note that it is very easy to
6165 disrupt a debugging session by sending the wrong packet at the wrong
6168 The compare-sections command allows you to compare section data on the
6169 target to what is in the executable file without uploading or
6170 downloading, by comparing CRC checksums.
6172 * Tracing can collect general expressions
6174 You may now collect general expressions at tracepoints. This requires
6175 further additions to the target-side stub; see tracepoint.c and
6176 doc/agentexpr.texi for further details.
6178 * mask-address variable for Mips
6180 For Mips targets, you may control the zeroing of the upper 32 bits of
6181 a 64-bit address by entering `set mask-address on'. This is mainly
6182 of interest to users of embedded R4xxx and R5xxx processors.
6184 * Higher serial baud rates
6186 GDB's serial code now allows you to specify baud rates 57600, 115200,
6187 230400, and 460800 baud. (Note that your host system may not be able
6188 to achieve all of these rates.)
6192 The i960 configuration now includes an initial implementation of a
6193 builtin simulator, contributed by Jim Wilson.
6196 *** Changes in GDB-4.17:
6198 * New native configurations
6200 Alpha GNU/Linux alpha*-*-linux*
6201 Unixware 2.x i[3456]86-unixware2*
6202 Irix 6.x mips*-sgi-irix6*
6203 PowerPC GNU/Linux powerpc-*-linux*
6204 PowerPC Solaris powerpcle-*-solaris*
6205 Sparc GNU/Linux sparc-*-linux*
6206 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6210 Argonaut Risc Chip (ARC) arc-*-*
6211 Hitachi H8/300S h8300*-*-*
6212 Matsushita MN10200 w/simulator mn10200-*-*
6213 Matsushita MN10300 w/simulator mn10300-*-*
6214 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6215 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6216 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6217 Mitsubishi D10V w/simulator d10v-*-*
6218 Mitsubishi M32R/D w/simulator m32r-*-elf*
6219 Tsqware Sparclet sparclet-*-*
6220 NEC V850 w/simulator v850-*-*
6222 * New debugging protocols
6224 ARM with RDI protocol arm*-*-*
6225 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6226 DDB and LSI variants of PMON protocol mips*-*-*
6227 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6228 PowerPC with SDS protocol powerpc{,le}-*-eabi
6229 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6233 All configurations can now understand and use the DWARF 2 debugging
6234 format. The choice is automatic, if the symbol file contains DWARF 2
6239 GDB now includes basic Java language support. This support is
6240 only useful with Java compilers that produce native machine code.
6242 * solib-absolute-prefix and solib-search-path
6244 For SunOS and SVR4 shared libraries, you may now set the prefix for
6245 loading absolute shared library symbol files, and the search path for
6246 locating non-absolute shared library symbol files.
6248 * Live range splitting
6250 GDB can now effectively debug code for which GCC has performed live
6251 range splitting as part of its optimization. See gdb/doc/LRS for
6252 more details on the expected format of the stabs information.
6256 GDB's support for the GNU Hurd, including thread debugging, has been
6257 updated to work with current versions of the Hurd.
6261 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6262 instruction set. ARM GDB automatically detects when Thumb
6263 instructions are in use, and adjusts disassembly and backtracing
6268 GDB's MIPS target configurations now handle the MIP16 16-bit
6273 GDB now includes support for overlays; if an executable has been
6274 linked such that multiple sections are based at the same address, GDB
6275 will decide which section to use for symbolic info. You can choose to
6276 control the decision manually, using overlay commands, or implement
6277 additional target-side support and use "overlay load-target" to bring
6278 in the overlay mapping. Do "help overlay" for more detail.
6282 The command "info symbol <address>" displays information about
6283 the symbol at the specified address.
6287 The standard remote protocol now includes an extension that allows
6288 asynchronous collection and display of trace data. This requires
6289 extensive support in the target-side debugging stub. Tracing mode
6290 includes a new interaction mode in GDB and new commands: see the
6291 file tracepoint.c for more details.
6295 Configurations for embedded MIPS now include a simulator contributed
6296 by Cygnus Solutions. The simulator supports the instruction sets
6297 of most MIPS variants.
6301 Sparc configurations may now include the ERC32 simulator contributed
6302 by the European Space Agency. The simulator is not built into
6303 Sparc targets by default; configure with --enable-sim to include it.
6307 For target configurations that may include multiple variants of a
6308 basic architecture (such as MIPS and SH), you may now set the
6309 architecture explicitly. "set arch" sets, "info arch" lists
6310 the possible architectures.
6312 *** Changes in GDB-4.16:
6314 * New native configurations
6316 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6317 M68K NetBSD m68k-*-netbsd*
6318 PowerPC AIX 4.x powerpc-*-aix*
6319 PowerPC MacOS powerpc-*-macos*
6320 PowerPC Windows NT powerpcle-*-cygwin32
6321 RS/6000 AIX 4.x rs6000-*-aix4*
6325 ARM with RDP protocol arm-*-*
6326 I960 with MON960 i960-*-coff
6327 MIPS VxWorks mips*-*-vxworks*
6328 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6329 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6331 Matra Sparclet sparclet-*-*
6335 The powerpc-eabi configuration now includes the PSIM simulator,
6336 contributed by Andrew Cagney, with assistance from Mike Meissner.
6337 PSIM is a very elaborate model of the PowerPC, including not only
6338 basic instruction set execution, but also details of execution unit
6339 performance and I/O hardware. See sim/ppc/README for more details.
6343 GDB now works with Solaris 2.5.
6345 * Windows 95/NT native
6347 GDB will now work as a native debugger on Windows 95 and Windows NT.
6348 To build it from source, you must use the "gnu-win32" environment,
6349 which uses a DLL to emulate enough of Unix to run the GNU tools.
6350 Further information, binaries, and sources are available at
6351 ftp.cygnus.com, under pub/gnu-win32.
6353 * dont-repeat command
6355 If a user-defined command includes the command `dont-repeat', then the
6356 command will not be repeated if the user just types return. This is
6357 useful if the command is time-consuming to run, so that accidental
6358 extra keystrokes don't run the same command many times.
6360 * Send break instead of ^C
6362 The standard remote protocol now includes an option to send a break
6363 rather than a ^C to the target in order to interrupt it. By default,
6364 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6366 * Remote protocol timeout
6368 The standard remote protocol includes a new variable `remotetimeout'
6369 that allows you to set the number of seconds before GDB gives up trying
6370 to read from the target. The default value is 2.
6372 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6374 By default GDB will automatically keep track of objects as they are
6375 loaded and unloaded by the dynamic linker. By using the command `set
6376 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6377 when shared library events occur, thus allowing you to set breakpoints
6378 in shared libraries which are explicitly loaded by the inferior.
6380 Note this feature does not work on hpux8. On hpux9 you must link
6381 /usr/lib/end.o into your program. This feature should work
6382 automatically on hpux10.
6384 * Irix 5.x hardware watchpoint support
6386 Irix 5 configurations now support the use of hardware watchpoints.
6388 * Mips protocol "SYN garbage limit"
6390 When debugging a Mips target using the `target mips' protocol, you
6391 may set the number of characters that GDB will ignore by setting
6392 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6393 every character. The default value is 1050.
6395 * Recording and replaying remote debug sessions
6397 If you set `remotelogfile' to the name of a file, gdb will write to it
6398 a recording of a remote debug session. This recording may then be
6399 replayed back to gdb using "gdbreplay". See gdbserver/README for
6400 details. This is useful when you have a problem with GDB while doing
6401 remote debugging; you can make a recording of the session and send it
6402 to someone else, who can then recreate the problem.
6404 * Speedups for remote debugging
6406 GDB includes speedups for downloading and stepping MIPS systems using
6407 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6408 and more efficient S-record downloading.
6410 * Memory use reductions and statistics collection
6412 GDB now uses less memory and reports statistics about memory usage.
6413 Try the `maint print statistics' command, for example.
6415 *** Changes in GDB-4.15:
6417 * Psymtabs for XCOFF
6419 The symbol reader for AIX GDB now uses partial symbol tables. This
6420 can greatly improve startup time, especially for large executables.
6422 * Remote targets use caching
6424 Remote targets now use a data cache to speed up communication with the
6425 remote side. The data cache could lead to incorrect results because
6426 it doesn't know about volatile variables, thus making it impossible to
6427 debug targets which use memory mapped I/O devices. `set remotecache
6428 off' turns the the data cache off.
6430 * Remote targets may have threads
6432 The standard remote protocol now includes support for multiple threads
6433 in the target system, using new protocol commands 'H' and 'T'. See
6434 gdb/remote.c for details.
6438 If GDB is configured with `--enable-netrom', then it will include
6439 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6440 acts as though it is a bank of ROM on the target board, but you can
6441 write into it over the network. GDB's support consists only of
6442 support for fast loading into the emulated ROM; to debug, you must use
6443 another protocol, such as standard remote protocol. The usual
6444 sequence is something like
6446 target nrom <netrom-hostname>
6448 target remote <netrom-hostname>:1235
6452 GDB now includes support for the Apple Macintosh, as a host only. It
6453 may be run as either an MPW tool or as a standalone application, and
6454 it can debug through the serial port. All the usual GDB commands are
6455 available, but to the target command, you must supply "serial" as the
6456 device type instead of "/dev/ttyXX". See mpw-README in the main
6457 directory for more information on how to build. The MPW configuration
6458 scripts */mpw-config.in support only a few targets, and only the
6459 mips-idt-ecoff target has been tested.
6463 GDB configuration now uses autoconf. This is not user-visible,
6464 but does simplify configuration and building.
6468 GDB now supports hpux10.
6470 *** Changes in GDB-4.14:
6472 * New native configurations
6474 x86 FreeBSD i[345]86-*-freebsd
6475 x86 NetBSD i[345]86-*-netbsd
6476 NS32k NetBSD ns32k-*-netbsd
6477 Sparc NetBSD sparc-*-netbsd
6481 A29K VxWorks a29k-*-vxworks
6482 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6483 CPU32 EST-300 emulator m68*-*-est*
6484 PowerPC ELF powerpc-*-elf
6487 * Alpha OSF/1 support for procfs
6489 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6490 possible to attach to running processes. As the mounting of the /proc
6491 filesystem is optional on the Alpha, GDB automatically determines
6492 the availability of /proc during startup. This can lead to problems
6493 if /proc is unmounted after GDB has been started.
6495 * Arguments to user-defined commands
6497 User commands may accept up to 10 arguments separated by whitespace.
6498 Arguments are accessed within the user command via $arg0..$arg9. A
6501 print $arg0 + $arg1 + $arg2
6503 To execute the command use:
6506 Defines the command "adder" which prints the sum of its three arguments.
6507 Note the arguments are text substitutions, so they may reference variables,
6508 use complex expressions, or even perform inferior function calls.
6510 * New `if' and `while' commands
6512 This makes it possible to write more sophisticated user-defined
6513 commands. Both commands take a single argument, which is the
6514 expression to evaluate, and must be followed by the commands to
6515 execute, one per line, if the expression is nonzero, the list being
6516 terminated by the word `end'. The `if' command list may include an
6517 `else' word, which causes the following commands to be executed only
6518 if the expression is zero.
6520 * Fortran source language mode
6522 GDB now includes partial support for Fortran 77. It will recognize
6523 Fortran programs and can evaluate a subset of Fortran expressions, but
6524 variables and functions may not be handled correctly. GDB will work
6525 with G77, but does not yet know much about symbols emitted by other
6528 * Better HPUX support
6530 Most debugging facilities now work on dynamic executables for HPPAs
6531 running hpux9 or later. You can attach to running dynamically linked
6532 processes, but by default the dynamic libraries will be read-only, so
6533 for instance you won't be able to put breakpoints in them. To change
6534 that behavior do the following before running the program:
6540 This will cause the libraries to be mapped private and read-write.
6541 To revert to the normal behavior, do this:
6547 You cannot set breakpoints or examine data in the library until after
6548 the library is loaded if the function/data symbols do not have
6551 GDB can now also read debug symbols produced by the HP C compiler on
6552 HPPAs (sorry, no C++, Fortran or 68k support).
6554 * Target byte order now dynamically selectable
6556 You can choose which byte order to use with a target system, via the
6557 commands "set endian big" and "set endian little", and you can see the
6558 current setting by using "show endian". You can also give the command
6559 "set endian auto", in which case GDB will use the byte order
6560 associated with the executable. Currently, only embedded MIPS
6561 configurations support dynamic selection of target byte order.
6563 * New DOS host serial code
6565 This version uses DPMI interrupts to handle buffered I/O, so you
6566 no longer need to run asynctsr when debugging boards connected to
6569 *** Changes in GDB-4.13:
6571 * New "complete" command
6573 This lists all the possible completions for the rest of the line, if it
6574 were to be given as a command itself. This is intended for use by emacs.
6576 * Trailing space optional in prompt
6578 "set prompt" no longer adds a space for you after the prompt you set. This
6579 allows you to set a prompt which ends in a space or one that does not.
6581 * Breakpoint hit counts
6583 "info break" now displays a count of the number of times the breakpoint
6584 has been hit. This is especially useful in conjunction with "ignore"; you
6585 can ignore a large number of breakpoint hits, look at the breakpoint info
6586 to see how many times the breakpoint was hit, then run again, ignoring one
6587 less than that number, and this will get you quickly to the last hit of
6590 * Ability to stop printing at NULL character
6592 "set print null-stop" will cause GDB to stop printing the characters of
6593 an array when the first NULL is encountered. This is useful when large
6594 arrays actually contain only short strings.
6596 * Shared library breakpoints
6598 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6599 breakpoints in shared libraries before the executable is run.
6601 * Hardware watchpoints
6603 There is a new hardware breakpoint for the watch command for sparclite
6604 targets. See gdb/sparclite/hw_breakpoint.note.
6606 Hardware watchpoints are also now supported under GNU/Linux.
6610 Annotations have been added. These are for use with graphical interfaces,
6611 and are still experimental. Currently only gdba.el uses these.
6613 * Improved Irix 5 support
6615 GDB now works properly with Irix 5.2.
6617 * Improved HPPA support
6619 GDB now works properly with the latest GCC and GAS.
6621 * New native configurations
6623 Sequent PTX4 i[34]86-sequent-ptx4
6624 HPPA running OSF/1 hppa*-*-osf*
6625 Atari TT running SVR4 m68*-*-sysv4*
6626 RS/6000 LynxOS rs6000-*-lynxos*
6630 OS/9000 i[34]86-*-os9k
6631 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6634 * Hitachi SH7000 and E7000-PC ICE support
6636 There is now support for communicating with the Hitachi E7000-PC ICE.
6637 This is available automatically when GDB is configured for the SH.
6641 As usual, a variety of small fixes and improvements, both generic
6642 and configuration-specific. See the ChangeLog for more detail.
6644 *** Changes in GDB-4.12:
6646 * Irix 5 is now supported
6650 GDB-4.12 on the HPPA has a number of changes which make it unable
6651 to debug the output from the currently released versions of GCC and
6652 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6653 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6654 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6657 *** Changes in GDB-4.11:
6659 * User visible changes:
6663 The "set remotedebug" option is now consistent between the mips remote
6664 target, remote targets using the gdb-specific protocol, UDI (AMD's
6665 debug protocol for the 29k) and the 88k bug monitor. It is now an
6666 integer specifying a debug level (normally 0 or 1, but 2 means more
6667 debugging info for the mips target).
6669 * DEC Alpha native support
6671 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6672 debug info, but GDB works fairly well with the DEC compiler and should
6673 work with a future GCC release. See the README file for a few
6674 Alpha-specific notes.
6676 * Preliminary thread implementation
6678 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6680 * LynxOS native and target support for 386
6682 This release has been hosted on LynxOS 2.2, and also can be configured
6683 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6686 * Improvements in C++ mangling/demangling.
6688 This release has much better g++ debugging, specifically in name
6689 mangling/demangling, virtual function calls, print virtual table,
6690 call methods, ...etc.
6692 *** Changes in GDB-4.10:
6694 * User visible changes:
6696 Remote debugging using the GDB-specific (`target remote') protocol now
6697 supports the `load' command. This is only useful if you have some
6698 other way of getting the stub to the target system, and you can put it
6699 somewhere in memory where it won't get clobbered by the download.
6701 Filename completion now works.
6703 When run under emacs mode, the "info line" command now causes the
6704 arrow to point to the line specified. Also, "info line" prints
6705 addresses in symbolic form (as well as hex).
6707 All vxworks based targets now support a user settable option, called
6708 vxworks-timeout. This option represents the number of seconds gdb
6709 should wait for responses to rpc's. You might want to use this if
6710 your vxworks target is, perhaps, a slow software simulator or happens
6711 to be on the far side of a thin network line.
6715 This release contains support for using a DEC alpha as a GDB host for
6716 cross debugging. Native alpha debugging is not supported yet.
6719 *** Changes in GDB-4.9:
6723 This is the first GDB release which is accompanied by a matching testsuite.
6724 The testsuite requires installation of dejagnu, which should be available
6725 via ftp from most sites that carry GNU software.
6729 'Cfront' style demangling has had its name changed to 'ARM' style, to
6730 emphasize that it was written from the specifications in the C++ Annotated
6731 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6732 disclaimers, it still generated too much confusion with users attempting to
6733 use gdb with AT&T cfront.
6737 GDB now uses a standard remote interface to a simulator library.
6738 So far, the library contains simulators for the Zilog Z8001/2, the
6739 Hitachi H8/300, H8/500 and Super-H.
6741 * New targets supported
6743 H8/300 simulator h8300-hitachi-hms or h8300hms
6744 H8/500 simulator h8500-hitachi-hms or h8500hms
6745 SH simulator sh-hitachi-hms or sh
6746 Z8000 simulator z8k-zilog-none or z8ksim
6747 IDT MIPS board over serial line mips-idt-ecoff
6749 Cross-debugging to GO32 targets is supported. It requires a custom
6750 version of the i386-stub.c module which is integrated with the
6751 GO32 memory extender.
6753 * New remote protocols
6755 MIPS remote debugging protocol.
6757 * New source languages supported
6759 This version includes preliminary support for Chill, a Pascal like language
6760 used by telecommunications companies. Chill support is also being integrated
6761 into the GNU compiler, but we don't know when it will be publically available.
6764 *** Changes in GDB-4.8:
6766 * HP Precision Architecture supported
6768 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6769 version of this support was available as a set of patches from the
6770 University of Utah. GDB does not support debugging of programs
6771 compiled with the HP compiler, because HP will not document their file
6772 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6773 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6775 Many problems in the preliminary version have been fixed.
6777 * Faster and better demangling
6779 We have improved template demangling and fixed numerous bugs in the GNU style
6780 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6781 character types (wchar_t) are now supported. Demangling of each symbol is now
6782 only done once, and is cached when the symbol table for a file is read in.
6783 This results in a small increase in memory usage for C programs, a moderate
6784 increase in memory usage for C++ programs, and a fantastic speedup in
6787 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6788 from the specifications in the Annotated Reference Manual, which AT&T's
6789 compiler does not actually implement.
6791 * G++ multiple inheritance compiler problem
6793 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6794 inheritance lattices was reworked to properly discover ambiguities. We
6795 recently found an example which causes this new algorithm to fail in a
6796 very subtle way, producing bad debug information for those classes.
6797 The file 'gcc.patch' (in this directory) can be applied to gcc to
6798 circumvent the problem. A future GCC release will contain a complete
6801 The previous G++ debug info problem (mentioned below for the gdb-4.7
6802 release) is fixed in gcc version 2.3.2.
6804 * Improved configure script
6806 The `configure' script will now attempt to guess your system type if
6807 you don't supply a host system type. The old scheme of supplying a
6808 host system triplet is preferable over using this. All the magic is
6809 done in the new `config.guess' script. Examine it for details.
6811 We have also brought our configure script much more in line with the FSF's
6812 version. It now supports the --with-xxx options. In particular,
6813 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6814 The resulting GDB will not be able to read arbitrary object file formats --
6815 only the format ``expected'' to be used on the configured target system.
6816 We hope to make this the default in a future release.
6818 * Documentation improvements
6820 There's new internal documentation on how to modify GDB, and how to
6821 produce clean changes to the code. We implore people to read it
6822 before submitting changes.
6824 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6825 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6826 `info' files are also provided. To build `info' files from scratch,
6827 you will need the latest `makeinfo' release, which will be available in
6828 a future texinfo-X.Y release.
6830 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6831 We're not sure exactly which versions have this problem, but it has
6832 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6833 or better. If that isn't possible, there is a patch in
6834 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6835 around this problem.
6839 GDB now supports array constants that can be used in expressions typed in by
6840 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6841 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6844 The new directory `gdb/sparclite' contains a program that demonstrates
6845 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6847 * New native hosts supported
6849 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6850 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6852 * New targets supported
6854 AMD 29k family via UDI a29k-amd-udi or udi29k
6856 * New file formats supported
6858 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6859 HPUX core files, and SCO 3.2v2 core files.
6863 Attaching to processes now works again; thanks for the many bug reports.
6865 We have also stomped on a bunch of core dumps caused by
6866 printf_filtered("%s") problems.
6868 We eliminated a copyright problem on the rpc and ptrace header files
6869 for VxWorks, which was discovered at the last minute during the 4.7
6870 release. You should now be able to build a VxWorks GDB.
6872 You can now interrupt gdb while an attached process is running. This
6873 will cause the attached process to stop, and give control back to GDB.
6875 We fixed problems caused by using too many file descriptors
6876 for reading symbols from object files and libraries. This was
6877 especially a problem for programs that used many (~100) shared
6880 The `step' command now only enters a subroutine if there is line number
6881 information for the subroutine. Otherwise it acts like the `next'
6882 command. Previously, `step' would enter subroutines if there was
6883 any debugging information about the routine. This avoids problems
6884 when using `cc -g1' on MIPS machines.
6886 * Internal improvements
6888 GDB's internal interfaces have been improved to make it easier to support
6889 debugging of multiple languages in the future.
6891 GDB now uses a common structure for symbol information internally.
6892 Minimal symbols (derived from linkage symbols in object files), partial
6893 symbols (from a quick scan of debug information), and full symbols
6894 contain a common subset of information, making it easier to write
6895 shared code that handles any of them.
6897 * New command line options
6899 We now accept --silent as an alias for --quiet.
6903 The memory-mapped-malloc library is now licensed under the GNU Library
6904 General Public License.
6906 *** Changes in GDB-4.7:
6908 * Host/native/target split
6910 GDB has had some major internal surgery to untangle the support for
6911 hosts and remote targets. Now, when you configure GDB for a remote
6912 target, it will no longer load in all of the support for debugging
6913 local programs on the host. When fully completed and tested, this will
6914 ensure that arbitrary host/target combinations are possible.
6916 The primary conceptual shift is to separate the non-portable code in
6917 GDB into three categories. Host specific code is required any time GDB
6918 is compiled on that host, regardless of the target. Target specific
6919 code relates to the peculiarities of the target, but can be compiled on
6920 any host. Native specific code is everything else: it can only be
6921 built when the host and target are the same system. Child process
6922 handling and core file support are two common `native' examples.
6924 GDB's use of /proc for controlling Unix child processes is now cleaner.
6925 It has been split out into a single module under the `target_ops' vector,
6926 plus two native-dependent functions for each system that uses /proc.
6928 * New hosts supported
6930 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6931 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6932 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6934 * New targets supported
6936 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6937 68030 and CPU32 m68030-*-*, m68332-*-*
6939 * New native hosts supported
6941 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6942 (386bsd is not well tested yet)
6943 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6945 * New file formats supported
6947 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6948 supports reading of `a.out.adobe' object files, which are an a.out
6949 format extended with minimal information about multiple sections.
6953 `show copying' is the same as the old `info copying'.
6954 `show warranty' is the same as `info warrantee'.
6955 These were renamed for consistency. The old commands continue to work.
6957 `info handle' is a new alias for `info signals'.
6959 You can now define pre-command hooks, which attach arbitrary command
6960 scripts to any command. The commands in the hook will be executed
6961 prior to the user's command. You can also create a hook which will be
6962 executed whenever the program stops. See gdb.texinfo.
6966 We now deal with Cfront style name mangling, and can even extract type
6967 info from mangled symbols. GDB can automatically figure out which
6968 symbol mangling style your C++ compiler uses.
6970 Calling of methods and virtual functions has been improved as well.
6974 The crash that occured when debugging Sun Ansi-C compiled binaries is
6975 fixed. This was due to mishandling of the extra N_SO stabs output
6978 We also finally got Ultrix 4.2 running in house, and fixed core file
6979 support, with help from a dozen people on the net.
6981 John M. Farrell discovered that the reason that single-stepping was so
6982 slow on all of the Mips based platforms (primarily SGI and DEC) was
6983 that we were trying to demangle and lookup a symbol used for internal
6984 purposes on every instruction that was being stepped through. Changing
6985 the name of that symbol so that it couldn't be mistaken for a C++
6986 mangled symbol sped things up a great deal.
6988 Rich Pixley sped up symbol lookups in general by getting much smarter
6989 about when C++ symbol mangling is necessary. This should make symbol
6990 completion (TAB on the command line) much faster. It's not as fast as
6991 we'd like, but it's significantly faster than gdb-4.6.
6995 A new user controllable variable 'call_scratch_address' can
6996 specify the location of a scratch area to be used when GDB
6997 calls a function in the target. This is necessary because the
6998 usual method of putting the scratch area on the stack does not work
6999 in systems that have separate instruction and data spaces.
7001 We integrated changes to support the 29k UDI (Universal Debugger
7002 Interface), but discovered at the last minute that we didn't have all
7003 of the appropriate copyright paperwork. We are working with AMD to
7004 resolve this, and hope to have it available soon.
7008 We have sped up the remote serial line protocol, especially for targets
7009 with lots of registers. It now supports a new `expedited status' ('T')
7010 message which can be used in place of the existing 'S' status message.
7011 This allows the remote stub to send only the registers that GDB
7012 needs to make a quick decision about single-stepping or conditional
7013 breakpoints, eliminating the need to fetch the entire register set for
7014 each instruction being stepped through.
7016 The GDB remote serial protocol now implements a write-through cache for
7017 registers, only re-reading the registers if the target has run.
7019 There is also a new remote serial stub for SPARC processors. You can
7020 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7021 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7022 processor with a serial port.
7026 Configure.in files have become much easier to read and modify. A new
7027 `table driven' format makes it more obvious what configurations are
7028 supported, and what files each one uses.
7032 There is a new opcodes library which will eventually contain all of the
7033 disassembly routines and opcode tables. At present, it only contains
7034 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7035 disassembler (binutils/objdump) to share these routines.
7037 The libiberty library is now copylefted under the GNU Library General
7038 Public License. This allows more liberal use, and was done so libg++
7039 can use it. This makes no difference to GDB, since the Library License
7040 grants all the rights from the General Public License.
7044 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7045 reference to the stabs symbol info used by the debugger. It is (as far
7046 as we know) the only published document on this fascinating topic. We
7047 encourage you to read it, compare it to the stabs information on your
7048 system, and send improvements on the document in general (to
7049 bug-gdb@prep.ai.mit.edu).
7051 And, of course, many bugs have been fixed.
7054 *** Changes in GDB-4.6:
7056 * Better support for C++ function names
7058 GDB now accepts as input the "demangled form" of C++ overloaded function
7059 names and member function names, and can do command completion on such names
7060 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7061 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7062 Make use of command completion, it is your friend.
7064 GDB also now accepts a variety of C++ mangled symbol formats. They are
7065 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7066 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7067 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7068 for the list of formats.
7070 * G++ symbol mangling problem
7072 Recent versions of gcc have a bug in how they emit debugging information for
7073 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7074 directory) can be applied to gcc to fix the problem. Alternatively, if you
7075 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7076 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7077 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7080 * New 'maintenance' command
7082 All of the commands related to hacking GDB internals have been moved out of
7083 the main command set, and now live behind the 'maintenance' command. This
7084 can also be abbreviated as 'mt'. The following changes were made:
7086 dump-me -> maintenance dump-me
7087 info all-breakpoints -> maintenance info breakpoints
7088 printmsyms -> maintenance print msyms
7089 printobjfiles -> maintenance print objfiles
7090 printpsyms -> maintenance print psymbols
7091 printsyms -> maintenance print symbols
7093 The following commands are new:
7095 maintenance demangle Call internal GDB demangler routine to
7096 demangle a C++ link name and prints the result.
7097 maintenance print type Print a type chain for a given symbol
7099 * Change to .gdbinit file processing
7101 We now read the $HOME/.gdbinit file before processing the argv arguments
7102 (e.g. reading symbol files or core files). This allows global parameters to
7103 be set, which will apply during the symbol reading. The ./.gdbinit is still
7104 read after argv processing.
7106 * New hosts supported
7108 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7110 GNU/Linux support i386-unknown-linux or linux
7112 We are also including code to support the HP/PA running BSD and HPUX. This
7113 is almost guaranteed not to work, as we didn't have time to test or build it
7114 for this release. We are including it so that the more adventurous (or
7115 masochistic) of you can play with it. We also had major problems with the
7116 fact that the compiler that we got from HP doesn't support the -g option.
7119 * New targets supported
7121 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7123 * More smarts about finding #include files
7125 GDB now remembers the compilation directory for all include files, and for
7126 all files from which C is generated (like yacc and lex sources). This
7127 greatly improves GDB's ability to find yacc/lex sources, and include files,
7128 especially if you are debugging your program from a directory different from
7129 the one that contains your sources.
7131 We also fixed a bug which caused difficulty with listing and setting
7132 breakpoints in include files which contain C code. (In the past, you had to
7133 try twice in order to list an include file that you hadn't looked at before.)
7135 * Interesting infernals change
7137 GDB now deals with arbitrary numbers of sections, where the symbols for each
7138 section must be relocated relative to that section's landing place in the
7139 target's address space. This work was needed to support ELF with embedded
7140 stabs used by Solaris-2.0.
7142 * Bug fixes (of course!)
7144 There have been loads of fixes for the following things:
7145 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7146 i960, stabs, DOS(GO32), procfs, etc...
7148 See the ChangeLog for details.
7150 *** Changes in GDB-4.5:
7152 * New machines supported (host and target)
7154 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7156 SGI Irix-4.x mips-sgi-irix4 or iris4
7158 * New malloc package
7160 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7161 Mmalloc is capable of handling mutiple heaps of memory. It is also
7162 capable of saving a heap to a file, and then mapping it back in later.
7163 This can be used to greatly speedup the startup of GDB by using a
7164 pre-parsed symbol table which lives in a mmalloc managed heap. For
7165 more details, please read mmalloc/mmalloc.texi.
7169 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7170 'help info proc' for details.
7172 * MIPS ecoff symbol table format
7174 The code that reads MIPS symbol table format is now supported on all hosts.
7175 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7178 * File name changes for MS-DOS
7180 Many files in the config directories have been renamed to make it easier to
7181 support GDB on MS-DOSe systems (which have very restrictive file name
7182 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7183 environment) is close to working but has some remaining problems. Note
7184 that debugging of DOS programs is not supported, due to limitations
7185 in the ``operating system'', but it can be used to host cross-debugging.
7187 * Cross byte order fixes
7189 Many fixes have been made to support cross debugging of Sparc and MIPS
7190 targets from hosts whose byte order differs.
7192 * New -mapped and -readnow options
7194 If memory-mapped files are available on your system through the 'mmap'
7195 system call, you can use the -mapped option on the `file' or
7196 `symbol-file' commands to cause GDB to write the symbols from your
7197 program into a reusable file. If the program you are debugging is
7198 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7199 Future GDB debugging sessions will notice the presence of this file,
7200 and will quickly map in symbol information from it, rather than reading
7201 the symbol table from the executable program. Using the '-mapped'
7202 option in a GDB `file' or `symbol-file' command has the same effect as
7203 starting GDB with the '-mapped' command-line option.
7205 You can cause GDB to read the entire symbol table immediately by using
7206 the '-readnow' option with any of the commands that load symbol table
7207 information (or on the GDB command line). This makes the command
7208 slower, but makes future operations faster.
7210 The -mapped and -readnow options are typically combined in order to
7211 build a `fred.syms' file that contains complete symbol information.
7212 A simple GDB invocation to do nothing but build a `.syms' file for future
7215 gdb -batch -nx -mapped -readnow programname
7217 The `.syms' file is specific to the host machine on which GDB is run.
7218 It holds an exact image of GDB's internal symbol table. It cannot be
7219 shared across multiple host platforms.
7221 * longjmp() handling
7223 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7224 siglongjmp() without losing control. This feature has not yet been ported to
7225 all systems. It currently works on many 386 platforms, all MIPS-based
7226 platforms (SGI, DECstation, etc), and Sun3/4.
7230 Preliminary work has been put in to support the new Solaris OS from Sun. At
7231 this time, it can control and debug processes, but it is not capable of
7236 As always, many many bug fixes. The major areas were with g++, and mipsread.
7237 People using the MIPS-based platforms should experience fewer mysterious
7238 crashes and trashed symbol tables.
7240 *** Changes in GDB-4.4:
7242 * New machines supported (host and target)
7244 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7246 BSD Reno on Vax vax-dec-bsd
7247 Ultrix on Vax vax-dec-ultrix
7249 * New machines supported (target)
7251 AMD 29000 embedded, using EBMON a29k-none-none
7255 GDB continues to improve its handling of C++. `References' work better.
7256 The demangler has also been improved, and now deals with symbols mangled as
7257 per the Annotated C++ Reference Guide.
7259 GDB also now handles `stabs' symbol information embedded in MIPS
7260 `ecoff' symbol tables. Since the ecoff format was not easily
7261 extensible to handle new languages such as C++, this appeared to be a
7262 good way to put C++ debugging info into MIPS binaries. This option
7263 will be supported in the GNU C compiler, version 2, when it is
7266 * New features for SVR4
7268 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7269 shared libraries. Debugging dynamically linked programs should present
7270 only minor differences from debugging statically linked programs.
7272 The `info proc' command will print out information about any process
7273 on an SVR4 system (including the one you are debugging). At the moment,
7274 it prints the address mappings of the process.
7276 If you bring up GDB on another SVR4 system, please send mail to
7277 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7279 * Better dynamic linking support in SunOS
7281 Reading symbols from shared libraries which contain debugging symbols
7282 now works properly. However, there remain issues such as automatic
7283 skipping of `transfer vector' code during function calls, which
7284 make it harder to debug code in a shared library, than to debug the
7285 same code linked statically.
7289 GDB is now using the latest `getopt' routines from the FSF. This
7290 version accepts the -- prefix for options with long names. GDB will
7291 continue to accept the old forms (-option and +option) as well.
7292 Various single letter abbreviations for options have been explicity
7293 added to the option table so that they won't get overshadowed in the
7294 future by other options that begin with the same letter.
7298 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7299 Many assorted bugs have been handled. Many more remain to be handled.
7300 See the various ChangeLog files (primarily in gdb and bfd) for details.
7303 *** Changes in GDB-4.3:
7305 * New machines supported (host and target)
7307 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7308 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7309 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7311 * Almost SCO Unix support
7313 We had hoped to support:
7314 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7315 (except for core file support), but we discovered very late in the release
7316 that it has problems with process groups that render gdb unusable. Sorry
7317 about that. I encourage people to fix it and post the fixes.
7319 * Preliminary ELF and DWARF support
7321 GDB can read ELF object files on System V Release 4, and can handle
7322 debugging records for C, in DWARF format, in ELF files. This support
7323 is preliminary. If you bring up GDB on another SVR4 system, please
7324 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7329 GDB now uses the latest `readline' library. One user-visible change
7330 is that two tabs will list possible command completions, which previously
7331 required typing M-? (meta-question mark, or ESC ?).
7335 The `stepi' bug that many of you noticed has been squashed.
7336 Many bugs in C++ have been handled. Many more remain to be handled.
7337 See the various ChangeLog files (primarily in gdb and bfd) for details.
7339 * State of the MIPS world (in case you wondered):
7341 GDB can understand the symbol tables emitted by the compilers
7342 supplied by most vendors of MIPS-based machines, including DEC. These
7343 symbol tables are in a format that essentially nobody else uses.
7345 Some versions of gcc come with an assembler post-processor called
7346 mips-tfile. This program is required if you want to do source-level
7347 debugging of gcc-compiled programs. I believe FSF does not ship
7348 mips-tfile with gcc version 1, but it will eventually come with gcc
7351 Debugging of g++ output remains a problem. g++ version 1.xx does not
7352 really support it at all. (If you're lucky, you should be able to get
7353 line numbers and stack traces to work, but no parameters or local
7354 variables.) With some work it should be possible to improve the
7357 When gcc version 2 is released, you will have somewhat better luck.
7358 However, even then you will get confusing results for inheritance and
7361 We will eventually provide full debugging of g++ output on
7362 DECstations. This will probably involve some kind of stabs-in-ecoff
7363 encapulation, but the details have not been worked out yet.
7366 *** Changes in GDB-4.2:
7368 * Improved configuration
7370 Only one copy of `configure' exists now, and it is not self-modifying.
7371 Porting BFD is simpler.
7375 The `step' and `next' commands now only stop at the first instruction
7376 of a source line. This prevents the multiple stops that used to occur
7377 in switch statements, for-loops, etc. `Step' continues to stop if a
7378 function that has debugging information is called within the line.
7382 Lots of small bugs fixed. More remain.
7384 * New host supported (not target)
7386 Intel 386 PC clone running Mach i386-none-mach
7389 *** Changes in GDB-4.1:
7391 * Multiple source language support
7393 GDB now has internal scaffolding to handle several source languages.
7394 It determines the type of each source file from its filename extension,
7395 and will switch expression parsing and number formatting to match the
7396 language of the function in the currently selected stack frame.
7397 You can also specifically set the language to be used, with
7398 `set language c' or `set language modula-2'.
7402 GDB now has preliminary support for the GNU Modula-2 compiler,
7403 currently under development at the State University of New York at
7404 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7405 continue through the fall of 1991 and into 1992.
7407 Other Modula-2 compilers are currently not supported, and attempting to
7408 debug programs compiled with them will likely result in an error as the
7409 symbol table is read. Feel free to work on it, though!
7411 There are hooks in GDB for strict type checking and range checking,
7412 in the `Modula-2 philosophy', but they do not currently work.
7416 GDB can now write to executable and core files (e.g. patch
7417 a variable's value). You must turn this switch on, specify
7418 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7419 by assigning a new value to a variable. Modifications take
7422 * Automatic SunOS shared library reading
7424 When you run your program, GDB automatically determines where its
7425 shared libraries (if any) have been loaded, and reads their symbols.
7426 The `share' command is no longer needed. This also works when
7427 examining core files.
7431 You can specify the number of lines that the `list' command shows.
7434 * New machines supported (host and target)
7436 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7437 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7438 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7440 * New hosts supported (not targets)
7442 IBM RT/PC: romp-ibm-aix or rtpc
7444 * New targets supported (not hosts)
7446 AMD 29000 embedded with COFF a29k-none-coff
7447 AMD 29000 embedded with a.out a29k-none-aout
7448 Ultracomputer remote kernel debug a29k-nyu-kern
7450 * New remote interfaces
7456 *** Changes in GDB-4.0:
7460 Wide output is wrapped at good places to make the output more readable.
7462 Gdb now supports cross-debugging from a host machine of one type to a
7463 target machine of another type. Communication with the target system
7464 is over serial lines. The ``target'' command handles connecting to the
7465 remote system; the ``load'' command will download a program into the
7466 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7467 also supports debugging of realtime processes running under VxWorks,
7468 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7469 stub on the target system.
7471 New CPUs supported include the AMD 29000 and Intel 960.
7473 GDB now reads object files and symbol tables via a ``binary file''
7474 library, which allows a single copy of GDB to debug programs of multiple
7475 object file types such as a.out and coff.
7477 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7478 refcard.dvi and refcard.ps are available to format it).
7481 * Control-Variable user interface simplified
7483 All variables that control the operation of the debugger can be set
7484 by the ``set'' command, and displayed by the ``show'' command.
7486 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7487 ``Show prompt'' produces the response:
7488 Gdb's prompt is new-gdb=>.
7490 What follows are the NEW set commands. The command ``help set'' will
7491 print a complete list of old and new set commands. ``help set FOO''
7492 will give a longer description of the variable FOO. ``show'' will show
7493 all of the variable descriptions and their current settings.
7495 confirm on/off: Enables warning questions for operations that are
7496 hard to recover from, e.g. rerunning the program while
7497 it is already running. Default is ON.
7499 editing on/off: Enables EMACS style command line editing
7500 of input. Previous lines can be recalled with
7501 control-P, the current line can be edited with control-B,
7502 you can search for commands with control-R, etc.
7505 history filename NAME: NAME is where the gdb command history
7506 will be stored. The default is .gdb_history,
7507 or the value of the environment variable
7510 history size N: The size, in commands, of the command history. The
7511 default is 256, or the value of the environment variable
7514 history save on/off: If this value is set to ON, the history file will
7515 be saved after exiting gdb. If set to OFF, the
7516 file will not be saved. The default is OFF.
7518 history expansion on/off: If this value is set to ON, then csh-like
7519 history expansion will be performed on
7520 command line input. The default is OFF.
7522 radix N: Sets the default radix for input and output. It can be set
7523 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7524 in the current radix, so "set radix 10" is always a no-op.
7526 height N: This integer value is the number of lines on a page. Default
7527 is 24, the current `stty rows'' setting, or the ``li#''
7528 setting from the termcap entry matching the environment
7531 width N: This integer value is the number of characters on a line.
7532 Default is 80, the current `stty cols'' setting, or the ``co#''
7533 setting from the termcap entry matching the environment
7536 Note: ``set screensize'' is obsolete. Use ``set height'' and
7537 ``set width'' instead.
7539 print address on/off: Print memory addresses in various command displays,
7540 such as stack traces and structure values. Gdb looks
7541 more ``symbolic'' if you turn this off; it looks more
7542 ``machine level'' with it on. Default is ON.
7544 print array on/off: Prettyprint arrays. New convenient format! Default
7547 print demangle on/off: Print C++ symbols in "source" form if on,
7550 print asm-demangle on/off: Same, for assembler level printouts
7553 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7556 * Support for Epoch Environment.
7558 The epoch environment is a version of Emacs v18 with windowing. One
7559 new command, ``inspect'', is identical to ``print'', except that if you
7560 are running in the epoch environment, the value is printed in its own
7564 * Support for Shared Libraries
7566 GDB can now debug programs and core files that use SunOS shared libraries.
7567 Symbols from a shared library cannot be referenced
7568 before the shared library has been linked with the program (this
7569 happens after you type ``run'' and before the function main() is entered).
7570 At any time after this linking (including when examining core files
7571 from dynamically linked programs), gdb reads the symbols from each
7572 shared library when you type the ``sharedlibrary'' command.
7573 It can be abbreviated ``share''.
7575 sharedlibrary REGEXP: Load shared object library symbols for files
7576 matching a unix regular expression. No argument
7577 indicates to load symbols for all shared libraries.
7579 info sharedlibrary: Status of loaded shared libraries.
7584 A watchpoint stops execution of a program whenever the value of an
7585 expression changes. Checking for this slows down execution
7586 tremendously whenever you are in the scope of the expression, but is
7587 quite useful for catching tough ``bit-spreader'' or pointer misuse
7588 problems. Some machines such as the 386 have hardware for doing this
7589 more quickly, and future versions of gdb will use this hardware.
7591 watch EXP: Set a watchpoint (breakpoint) for an expression.
7593 info watchpoints: Information about your watchpoints.
7595 delete N: Deletes watchpoint number N (same as breakpoints).
7596 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7597 enable N: Re-enables watchpoint number N (same as breakpoints).
7600 * C++ multiple inheritance
7602 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7605 * C++ exception handling
7607 Gdb now supports limited C++ exception handling. Besides the existing
7608 ability to breakpoint on an exception handler, gdb can breakpoint on
7609 the raising of an exception (before the stack is peeled back to the
7612 catch FOO: If there is a FOO exception handler in the dynamic scope,
7613 set a breakpoint to catch exceptions which may be raised there.
7614 Multiple exceptions (``catch foo bar baz'') may be caught.
7616 info catch: Lists all exceptions which may be caught in the
7617 current stack frame.
7620 * Minor command changes
7622 The command ``call func (arg, arg, ...)'' now acts like the print
7623 command, except it does not print or save a value if the function's result
7624 is void. This is similar to dbx usage.
7626 The ``up'' and ``down'' commands now always print the frame they end up
7627 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7628 frames without printing.
7630 * New directory command
7632 'dir' now adds directories to the FRONT of the source search path.
7633 The path starts off empty. Source files that contain debug information
7634 about the directory in which they were compiled can be found even
7635 with an empty path; Sun CC and GCC include this information. If GDB can't
7636 find your source file in the current directory, type "dir .".
7638 * Configuring GDB for compilation
7640 For normal use, type ``./configure host''. See README or gdb.texinfo
7643 GDB now handles cross debugging. If you are remotely debugging between
7644 two different machines, type ``./configure host -target=targ''.
7645 Host is the machine where GDB will run; targ is the machine
7646 where the program that you are debugging will run.