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 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
15 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
16 of the GDB settings and the GDB maintenance settings. They are handy
17 for changing the logic of user defined commands depending on the
20 * GDB now supports Thread Local Storage (TLS) variables on several
21 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
22 architectures require kernel changes. TLS is not yet supported for
23 amd64 and i386 process core dumps.
25 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
26 addresses that required unmasking are shown in the backtrace with the
29 * Two new convenience functions $_cimag and $_creal that extract the
30 imaginary and real parts respectively from complex numbers.
32 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
33 provide the exitcode or exit status of the shell commands launched by
34 GDB commands such as "shell", "pipe" and "make".
36 * The RX port now supports XML target descriptions.
38 * GDB now shows the Ada task names at more places, e.g. in task switching
41 * GDB can now be compiled with Python 3 on Windows.
43 * New convenience variable $_ada_exception holds the address of the
44 Ada exception being thrown. This is set by Ada-related catchpoints.
46 * GDB can now place breakpoints on nested functions and subroutines in
47 Fortran code. The '::' operator can be used between parent and
48 child scopes when placing breakpoints, for example:
50 (gdb) break outer_function::inner_function
52 The 'outer_function::' prefix is only needed if 'inner_function' is
53 not visible in the current scope.
55 * In addition to the system-wide gdbinit file, if configured with
56 --with-system-gdbinit-dir, GDB will now also load files in that directory
57 as system gdbinit files, unless the -nx or -n flag is provided. Files
58 with extensions .gdb, .py and .scm are supported as long as GDB was
59 compiled with support for that language.
61 * GDB now supports multithreaded symbol loading for higher performance.
62 This feature is still in testing, so it is disabled by default. You
63 can turn it on using 'maint set worker-threads unlimited'.
67 ** The gdb.Value type has a new method 'format_string' which returns a
68 string representing the value. The formatting is controlled by the
69 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
70 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
71 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
73 ** gdb.Type has a new property 'objfile' which returns the objfile the
76 ** The frame information printed by the python frame filtering code
77 is now consistent with what the 'backtrace' command prints when
78 there are no filters, or when the 'backtrace' '-no-filters' option
81 ** The new function gdb.lookup_static_symbol can be used to look up
82 symbols with static linkage.
84 ** The new function gdb.lookup_static_symbols can be used to look up
85 all static symbols with static linkage.
87 ** gdb.Objfile has new methods 'lookup_global_symbol' and
88 'lookup_static_symbol' to lookup a symbol from this objfile only.
90 ** gdb.Block now supports the dictionary syntax for accessing symbols in
91 this block (e.g. block['local_variable']).
95 | [COMMAND] | SHELL_COMMAND
96 | -d DELIM COMMAND DELIM SHELL_COMMAND
97 pipe [COMMAND] | SHELL_COMMAND
98 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
99 Executes COMMAND and sends its output to SHELL_COMMAND.
100 With no COMMAND, repeat the last executed command
101 and send its output to SHELL_COMMAND.
103 with SETTING [VALUE] [-- COMMAND]
104 w SETTING [VALUE] [-- COMMAND]
105 Temporarily set SETTING, run COMMAND, and restore SETTING.
106 Usage: with SETTING -- COMMAND
107 With no COMMAND, repeats the last executed command.
108 SETTING is any GDB setting you can change with the "set"
109 subcommands. For example, 'with language c -- print someobj'
110 temporarily switches to the C language in order to print someobj.
111 Settings can be combined: 'w lang c -- w print elements unlimited --
112 usercmd' switches to the C language and runs usercmd with no limit
113 of array elements to print.
115 maint with SETTING [VALUE] [-- COMMAND]
116 Like "with", but works with "maintenance set" settings.
118 set may-call-functions [on|off]
119 show may-call-functions
120 This controls whether GDB will attempt to call functions in
121 the program, such as with expressions in the print command. It
122 defaults to on. Calling functions in the program being debugged
123 can have undesired side effects. It is now possible to forbid
124 such function calls. If function calls are forbidden, GDB will throw
125 an error when a command (such as print expression) calls a function
128 set print finish [on|off]
130 This controls whether the `finish' command will display the value
131 that is returned by the current function. When `off', the value is
132 still entered into the value history, but it is not printed. The
137 Allows deeply nested structures to be simplified when printing by
138 replacing deeply nested parts (beyond the max-depth) with ellipses.
139 The default max-depth is 20, but this can be set to unlimited to get
140 the old behavior back.
142 set logging debugredirect [on|off]
143 By default, GDB debug output will go to both the terminal and the logfile.
144 Set if you want debug output to go only to the log file.
146 set style title foreground COLOR
147 set style title background COLOR
148 set style title intensity VALUE
149 Control the styling of titles.
151 set style highlight foreground COLOR
152 set style highlight background COLOR
153 set style highlight intensity VALUE
154 Control the styling of highlightings.
156 maint set worker-threads
157 maint show worker-threads
158 Control the number of worker threads that can be used by GDB. The
159 default is 0. "unlimited" lets GDB choose a number that is
160 reasonable. Currently worker threads are only used when demangling
161 the names of linker symbols.
163 maint set test-settings KIND
164 maint show test-settings KIND
165 A set of commands used by the testsuite for exercising the settings
168 maint set tui-resize-message [on|off]
169 maint show tui-resize-message
170 Control whether GDB prints a message each time the terminal is
171 resized when in TUI mode. This is primarily useful for testing the
174 set print frame-info [short-location|location|location-and-address
175 |source-and-location|source-line|auto]
176 show print frame-info
177 This controls what frame information is printed by the commands printing
178 a frame. This setting will e.g. influence the behaviour of 'backtrace',
179 'frame', 'stepi'. The python frame filtering also respect this setting.
180 The 'backtrace' '-frame-info' option can override this global setting.
182 info modules [-q] [REGEXP]
183 Return a list of Fortran modules matching REGEXP, or all modules if
186 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
187 Return a list of functions within all modules, grouped by module.
188 The list of functions can be restricted with the optional regular
189 expressions. MODULE_REGEXP matches against the module name,
190 TYPE_REGEXP matches against the function type signature, and REGEXP
191 matches against the function name.
193 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
194 Return a list of variables within all modules, grouped by module.
195 The list of variables can be restricted with the optional regular
196 expressions. MODULE_REGEXP matches against the module name,
197 TYPE_REGEXP matches against the variable type, and REGEXP matches
198 against the variable name.
200 set debug remote-packet-max-chars
201 show debug remote-packet-max-chars
202 Controls the number of characters to output in a remote packet when using
204 The default is 512 bytes.
209 The "help" command uses the title style to enhance the
210 readibility of its output by styling the classes and
214 Similarly to "help", the "apropos" command also uses the
215 title style for the command names. "apropos" accepts now
216 a flag "-v" (verbose) to show the full documentation
217 of matching commands and to use the highlight style to mark
218 the documentation parts matching REGEXP.
222 The GDB printf and eval commands can now print C-style and Ada-style
223 string convenience variables without calling functions in the program.
224 This allows to do formatted printing of strings without having
225 a running inferior, or when debugging a core dump.
227 info sources [-dirname | -basename] [--] [REGEXP]
228 This command has now optional arguments to only print the files
229 whose names match REGEXP. The arguments -dirname and -basename
230 allow to restrict matching respectively to the dirname and basename
234 The "show style" and its subcommands are now styling
235 a style name in their output using its own style, to help
236 the user visualize the different styles.
238 set print frame-arguments
239 The new value 'presence' indicates to only indicate the presence of
240 arguments using ..., instead of printing argument names and values.
242 set print raw-frame-arguments
243 show print raw-frame-arguments
245 These commands replace the similarly-named "set/show print raw
246 frame-arguments" commands (now with a dash instead of a space). The
247 old commands are now deprecated and may be removed in a future
250 maint test-options require-delimiter
251 maint test-options unknown-is-error
252 maint test-options unknown-is-operand
253 maint show test-options-completion-result
254 Commands used by the testsuite to validate the command options
257 focus, winheight, +, -, >, <
258 These commands are now case-sensitive.
260 * New command options, command completion
262 GDB now has a standard infrastructure to support dash-style command
263 options ('-OPT'). One benefit is that commands that use it can
264 easily support completion of command line arguments. Try "CMD
265 -[TAB]" or "help CMD" to find options supported by a command. Over
266 time, we intend to migrate most commands to this infrastructure. A
267 number of commands got support for new command options in this
270 ** The "print" and "compile print" commands now support a number of
271 options that allow overriding relevant global print settings as
272 set by "set print" subcommands:
276 -array-indexes [on|off]
277 -elements NUMBER|unlimited
281 -repeats NUMBER|unlimited
282 -static-members [on|off]
287 Note that because the "print"/"compile print" commands accept
288 arbitrary expressions which may look like options (including
289 abbreviations), if you specify any command option, then you must
290 use a double dash ("--") to mark the end of argument processing.
292 ** The "backtrace" command now supports a number of options that
293 allow overriding relevant global print settings as set by "set
294 backtrace" and "set print" subcommands:
296 -entry-values no|only|preferred|if-needed|both|compact|default
297 -frame-arguments all|scalars|none
298 -raw-frame-arguments [on|off]
299 -frame-info auto|source-line|location|source-and-location
300 |location-and-address|short-location
304 In addition, the full/no-filters/hide qualifiers are now also
305 exposed as command options too:
311 ** The "frame apply", "tfaas" and "faas" commands similarly now
312 support the following options:
317 ** The new "info sources" options -dirname and -basename options
318 are using the standard '-OPT' infrastructure.
320 All options above can also be abbreviated. The argument of boolean
321 (on/off) options can be 0/1 too, and also the argument is assumed
322 "on" if omitted. This allows writing compact command invocations,
325 (gdb) p -r -p -o 0 -- *myptr
327 The above is equivalent to:
329 (gdb) print -raw -pretty -object off -- *myptr
331 ** The "info types" command now supports the '-q' flag to disable
332 printing of some header information in a similar fashion to "info
333 variables" and "info functions".
335 ** The "info variables", "info functions", and "whereis" commands
336 now take a '-n' flag that excludes non-debug symbols (symbols
337 from the symbol table, not from the debug info such as DWARF)
340 * Completion improvements
342 ** GDB can now complete the options of the "thread apply all" and
343 "taas" commands, and their "-ascending" option can now be
346 ** GDB can now complete the options of the "info threads", "info
347 functions", "info variables", "info locals", and "info args"
350 ** GDB can now complete the options of the "compile file" and
351 "compile code" commands. The "compile file" command now
352 completes on filenames.
354 ** GDB can now complete the backtrace command's
355 "full/no-filters/hide" qualifiers.
357 * In settings, you can now abbreviate "unlimited".
359 E.g., "set print elements u" is now equivalent to "set print
365 This lists all the possible completions for the rest of the line, if it
366 were to be given as a command itself. This is intended for use by MI
367 frontends in cases when separate CLI and MI channels cannot be used.
369 -catch-throw, -catch-rethrow, and -catch-catch
370 These can be used to catch C++ exceptions in a similar fashion to
371 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
373 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
374 These commands are the MI equivalent of the CLI commands 'info
375 functions', 'info types', and 'info variables' respectively.
377 -symbol-info-modules, this is the MI equivalent of the CLI 'info
382 ** The default version of the MI interpreter is now 3 (-i=mi3).
384 ** The output of information about multi-location breakpoints (which is
385 syntactically incorrect in MI 2) has changed in MI 3. This affects
386 the following commands and events:
390 - =breakpoint-created
391 - =breakpoint-modified
393 The -fix-multi-location-breakpoint-output command can be used to enable
394 this behavior with previous MI versions.
396 ** Backtraces and frames include a new optional field addr_flags which is
397 given after the addr field. On AArch64 this contains PAC if the address
398 has been masked in the frame. On all other targets the field is not
403 The testsuite now creates the files gdb.cmd (containing the arguments
404 used to launch GDB) and gdb.in (containing all the commands sent to
405 GDB) in the output directory for each test script. Multiple invocations
406 are appended with .1, .2, .3 etc.
408 * Building GDB and GDBserver now requires GNU make >= 3.82.
410 Using another implementation of the make program or an earlier version of
411 GNU make to build GDB or GDBserver is not supported.
413 * Building GDB now requires GNU readline >= 7.0.
415 GDB now bundles GNU readline 8.0, but if you choose to use
416 --with-system-readline, only readline >= 7.0 can be used.
418 * The TUI SingleKey keymap is now named "SingleKey". This can be used
419 from .inputrc to bind keys in this keymap. This feature is only
420 available when gdb is built against GNU readline 8.0 or later.
422 * Removed targets and native configurations
424 GDB no longer supports debugging the Cell Broadband Engine. This includes
425 both debugging standalone Cell/B.E. SPU applications and integrated debugging
426 of Cell/B.E. applications that use both the PPU and SPU architectures.
432 * Removed targets and native configurations
434 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
437 *** Changes in GDB 8.3
439 * GDB and GDBserver now support access to additional registers on
440 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
443 * GDB now has experimental support for the compilation and injection of
444 C++ source code into the inferior. This beta release does not include
445 support for several language features, such as templates, constructors,
448 This feature requires GCC 7.1 or higher built with libcp1.so
451 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
452 can be passed using the '[ADDRESS]:PORT' notation, or the regular
453 'ADDRESS:PORT' method.
455 * DWARF index cache: GDB can now automatically save indices of DWARF
456 symbols on disk to speed up further loading of the same binaries.
458 * Ada task switching is now supported on aarch64-elf targets when
459 debugging a program using the Ravenscar Profile. For more information,
460 see the "Tasking Support when using the Ravenscar Profile" section
461 in the GDB user manual.
463 * GDB in batch mode now exits with status 1 if the last command to be
466 * The RISC-V target now supports target descriptions.
468 * System call catchpoints now support system call aliases on FreeBSD.
469 When the ABI of a system call changes in FreeBSD, this is
470 implemented by leaving a compatibility system call using the old ABI
471 at the existing number and allocating a new system call number for
472 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
473 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
474 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
475 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
476 so that a system call catchpoint for the 'kevent' system call will
477 catch invocations of both the 'kevent' and 'freebsd11_kevent'
478 binaries. This ensures that 'kevent' system calls are caught for
479 binaries using either the old or new ABIs.
481 * Terminal styling is now available for the CLI and the TUI. GNU
482 Source Highlight can additionally be used to provide styling of
483 source code snippets. See the "set style" commands, below, for more
486 * Removed support for old demangling styles arm, edg, gnu, hp and
491 set debug compile-cplus-types
492 show debug compile-cplus-types
493 Control the display of debug output about type conversion in the
494 C++ compile feature. Commands have no effect while compiliong
499 Control whether debug output about files/functions skipping is
502 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
503 Apply a command to some frames.
504 FLAG arguments allow to control what output to produce and how to handle
505 errors raised when applying COMMAND to a frame.
508 Apply a command to all threads (ignoring errors and empty output).
509 Shortcut for 'thread apply all -s COMMAND'.
512 Apply a command to all frames (ignoring errors and empty output).
513 Shortcut for 'frame apply all -s COMMAND'.
516 Apply a command to all frames of all threads (ignoring errors and empty
518 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
520 maint set dwarf unwinders (on|off)
521 maint show dwarf unwinders
522 Control whether DWARF unwinders can be used.
525 Display a list of open files for a process.
529 Changes to the "frame", "select-frame", and "info frame" CLI commands.
530 These commands all now take a frame specification which
531 is either a frame level, or one of the keywords 'level', 'address',
532 'function', or 'view' followed by a parameter. Selecting a frame by
533 address, or viewing a frame outside the current backtrace now
534 requires the use of a keyword. Selecting a frame by level is
535 unchanged. The MI comment "-stack-select-frame" is unchanged.
537 target remote FILENAME
538 target extended-remote FILENAME
539 If FILENAME is a Unix domain socket, GDB will attempt to connect
540 to this socket instead of opening FILENAME as a character device.
542 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
543 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
544 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
545 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
546 These commands can now print only the searched entities
547 matching the provided regexp(s), giving a condition
548 on the entity names or entity types. The flag -q disables
549 printing headers or informations messages.
555 These commands now determine the syntax for the shown entities
556 according to the language chosen by `set language'. In particular,
557 `set language auto' means to automatically choose the language of
560 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
561 The 'thread apply' command accepts new FLAG arguments.
562 FLAG arguments allow to control what output to produce and how to handle
563 errors raised when applying COMMAND to a thread.
565 set tui tab-width NCHARS
566 show tui tab-width NCHARS
567 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
569 set style enabled [on|off]
571 Enable or disable terminal styling. Styling is enabled by default
572 on most hosts, but disabled by default when in batch mode.
574 set style sources [on|off]
576 Enable or disable source code styling. Source code styling is
577 enabled by default, but only takes effect if styling in general is
578 enabled, and if GDB was linked with GNU Source Highlight.
580 set style filename foreground COLOR
581 set style filename background COLOR
582 set style filename intensity VALUE
583 Control the styling of file names.
585 set style function foreground COLOR
586 set style function background COLOR
587 set style function intensity VALUE
588 Control the styling of function names.
590 set style variable foreground COLOR
591 set style variable background COLOR
592 set style variable intensity VALUE
593 Control the styling of variable names.
595 set style address foreground COLOR
596 set style address background COLOR
597 set style address intensity VALUE
598 Control the styling of addresses.
602 ** The '-data-disassemble' MI command now accepts an '-a' option to
603 disassemble the whole function surrounding the given program
604 counter value or function name. Support for this feature can be
605 verified by using the "-list-features" command, which should
606 contain "data-disassemble-a-option".
608 ** Command responses and notifications that include a frame now include
609 the frame's architecture in a new "arch" attribute.
611 * New native configurations
613 GNU/Linux/RISC-V riscv*-*-linux*
614 FreeBSD/riscv riscv*-*-freebsd*
618 GNU/Linux/RISC-V riscv*-*-linux*
620 CSKY GNU/LINUX csky*-*-linux
621 FreeBSD/riscv riscv*-*-freebsd*
623 GNU/Linux/OpenRISC or1k*-*-linux*
627 GDB no longer supports native debugging on versions of MS-Windows
632 ** GDB no longer supports Python versions less than 2.6.
634 ** The gdb.Inferior type has a new 'progspace' property, which is the program
635 space associated to that inferior.
637 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
638 of objfiles associated to that program space.
640 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
641 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
644 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
645 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
646 correct and did not work properly.
648 ** The gdb.Value type has a new constructor, which is used to construct a
649 gdb.Value from a Python buffer object and a gdb.Type.
655 Enable or disable the undefined behavior sanitizer. This is
656 disabled by default, but passing --enable-ubsan=yes or
657 --enable-ubsan=auto to configure will enable it. Enabling this can
658 cause a performance penalty. The undefined behavior sanitizer was
659 first introduced in GCC 4.9.
661 *** Changes in GDB 8.2
663 * The 'set disassembler-options' command now supports specifying options
666 * The 'symbol-file' command now accepts an '-o' option to add a relative
667 offset to all sections.
669 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
670 a relative offset to all sections, but it allows to override the load
671 address of individual sections using '-s'.
673 * The 'add-symbol-file' command no longer requires the second argument
674 (address of the text section).
676 * The endianness used with the 'set endian auto' mode in the absence of
677 an executable selected for debugging is now the last endianness chosen
678 either by one of the 'set endian big' and 'set endian little' commands
679 or by inferring from the last executable used, rather than the startup
682 * The pager now allows a "c" response, meaning to disable the pager
683 for the rest of the current command.
685 * The commands 'info variables/functions/types' now show the source line
686 numbers of symbol definitions when available.
688 * 'info proc' now works on running processes on FreeBSD systems and core
689 files created on FreeBSD systems.
691 * C expressions can now use _Alignof, and C++ expressions can now use
694 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
695 the vector length while the process is running.
701 Control display of debugging info regarding the FreeBSD native target.
703 set|show varsize-limit
704 This new setting allows the user to control the maximum size of Ada
705 objects being printed when those objects have a variable type,
706 instead of that maximum size being hardcoded to 65536 bytes.
708 set|show record btrace cpu
709 Controls the processor to be used for enabling errata workarounds for
712 maint check libthread-db
713 Run integrity checks on the current inferior's thread debugging
716 maint set check-libthread-db (on|off)
717 maint show check-libthread-db
718 Control whether to run integrity checks on inferior specific thread
719 debugging libraries as they are loaded. The default is not to
724 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
726 ** The commands attached to a breakpoint can be set by assigning to
727 the breakpoint's "commands" field.
729 ** gdb.execute can now execute multi-line gdb commands.
731 ** The new functions gdb.convenience_variable and
732 gdb.set_convenience_variable can be used to get and set the value
733 of convenience variables.
735 ** A gdb.Parameter will no longer print the "set" help text on an
736 ordinary "set"; instead by default a "set" will be silent unless
737 the get_set_string method returns a non-empty string.
741 RiscV ELF riscv*-*-elf
743 * Removed targets and native configurations
745 m88k running OpenBSD m88*-*-openbsd*
746 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
747 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
748 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
750 * Aarch64/Linux hardware watchpoints improvements
752 Hardware watchpoints on unaligned addresses are now properly
753 supported when running Linux kernel 4.10 or higher: read and access
754 watchpoints are no longer spuriously missed, and all watchpoints
755 lengths between 1 and 8 bytes are supported. On older kernels,
756 watchpoints set on unaligned addresses are no longer missed, with
757 the tradeoff that there is a possibility of false hits being
762 --enable-codesign=CERT
763 This can be used to invoke "codesign -s CERT" after building gdb.
764 This option is useful on macOS, where code signing is required for
765 gdb to work properly.
767 --disable-gdbcli has been removed
768 This is now silently accepted, but does nothing.
770 *** Changes in GDB 8.1
772 * GDB now supports dynamically creating arbitrary register groups specified
773 in XML target descriptions. This allows for finer grain grouping of
774 registers on systems with a large amount of registers.
776 * The 'ptype' command now accepts a '/o' flag, which prints the
777 offsets and sizes of fields in a struct, like the pahole(1) tool.
779 * New "--readnever" command line option instructs GDB to not read each
780 symbol file's symbolic debug information. This makes startup faster
781 but at the expense of not being able to perform symbolic debugging.
782 This option is intended for use cases where symbolic debugging will
783 not be used, e.g., when you only need to dump the debuggee's core.
785 * GDB now uses the GNU MPFR library, if available, to emulate target
786 floating-point arithmetic during expression evaluation when the target
787 uses different floating-point formats than the host. At least version
788 3.1 of GNU MPFR is required.
790 * GDB now supports access to the guarded-storage-control registers and the
791 software-based guarded-storage broadcast control registers on IBM z14.
793 * On Unix systems, GDB now supports transmitting environment variables
794 that are to be set or unset to GDBserver. These variables will
795 affect the environment to be passed to the remote inferior.
797 To inform GDB of environment variables that are to be transmitted to
798 GDBserver, use the "set environment" command. Only user set
799 environment variables are sent to GDBserver.
801 To inform GDB of environment variables that are to be unset before
802 the remote inferior is started by the GDBserver, use the "unset
803 environment" command.
805 * Completion improvements
807 ** GDB can now complete function parameters in linespecs and
808 explicit locations without quoting. When setting breakpoints,
809 quoting around functions names to help with TAB-completion is
810 generally no longer necessary. For example, this now completes
813 (gdb) b function(in[TAB]
814 (gdb) b function(int)
816 Related, GDB is no longer confused with completing functions in
817 C++ anonymous namespaces:
820 (gdb) b (anonymous namespace)::[TAB][TAB]
821 (anonymous namespace)::a_function()
822 (anonymous namespace)::b_function()
824 ** GDB now has much improved linespec and explicit locations TAB
825 completion support, that better understands what you're
826 completing and offers better suggestions. For example, GDB no
827 longer offers data symbols as possible completions when you're
828 setting a breakpoint.
830 ** GDB now TAB-completes label symbol names.
832 ** The "complete" command now mimics TAB completion accurately.
834 * New command line options (gcore)
837 Dump all memory mappings.
839 * Breakpoints on C++ functions are now set on all scopes by default
841 By default, breakpoints on functions/methods are now interpreted as
842 specifying all functions with the given name ignoring missing
843 leading scopes (namespaces and classes).
845 For example, assuming a C++ program with symbols named:
850 both commands "break func()" and "break B::func()" set a breakpoint
853 You can use the new flag "-qualified" to override this. This makes
854 GDB interpret the specified function name as a complete
855 fully-qualified name instead. For example, using the same C++
856 program, the "break -q B::func" command sets a breakpoint on
857 "B::func", only. A parameter has been added to the Python
858 gdb.Breakpoint constructor to achieve the same result when creating
859 a breakpoint from Python.
861 * Breakpoints on functions marked with C++ ABI tags
863 GDB can now set breakpoints on functions marked with C++ ABI tags
864 (e.g., [abi:cxx11]). See here for a description of ABI tags:
865 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
867 Functions with a C++11 abi tag are demangled/displayed like this:
869 function[abi:cxx11](int)
872 You can now set a breakpoint on such functions simply as if they had
875 (gdb) b function(int)
877 Or if you need to disambiguate between tags, like:
879 (gdb) b function[abi:other_tag](int)
881 Tab completion was adjusted accordingly as well.
885 ** New events gdb.new_inferior, gdb.inferior_deleted, and
886 gdb.new_thread are emitted. See the manual for further
887 description of these.
889 ** A new function, "gdb.rbreak" has been added to the Python API.
890 This function allows the setting of a large number of breakpoints
891 via a regex pattern in Python. See the manual for further details.
893 ** Python breakpoints can now accept explicit locations. See the
894 manual for a further description of this feature.
897 * New features in the GDB remote stub, GDBserver
899 ** GDBserver is now able to start inferior processes with a
900 specified initial working directory.
902 The user can set the desired working directory to be used from
903 GDB using the new "set cwd" command.
905 ** New "--selftest" command line option runs some GDBserver self
906 tests. These self tests are disabled in releases.
908 ** On Unix systems, GDBserver now does globbing expansion and variable
909 substitution in inferior command line arguments.
911 This is done by starting inferiors using a shell, like GDB does.
912 See "set startup-with-shell" in the user manual for how to disable
913 this from GDB when using "target extended-remote". When using
914 "target remote", you can disable the startup with shell by using the
915 new "--no-startup-with-shell" GDBserver command line option.
917 ** On Unix systems, GDBserver now supports receiving environment
918 variables that are to be set or unset from GDB. These variables
919 will affect the environment to be passed to the inferior.
921 * When catching an Ada exception raised with a message, GDB now prints
922 the message in the catchpoint hit notification. In GDB/MI mode, that
923 information is provided as an extra field named "exception-message"
924 in the *stopped notification.
926 * Trait objects can now be inspected When debugging Rust code. This
927 requires compiler support which will appear in Rust 1.24.
931 QEnvironmentHexEncoded
932 Inform GDBserver of an environment variable that is to be passed to
933 the inferior when starting it.
936 Inform GDBserver of an environment variable that is to be unset
937 before starting the remote inferior.
940 Inform GDBserver that the environment should be reset (i.e.,
941 user-set environment variables should be unset).
944 Indicates whether the inferior must be started with a shell or not.
947 Tell GDBserver that the inferior to be started should use a specific
950 * The "maintenance print c-tdesc" command now takes an optional
951 argument which is the file name of XML target description.
953 * The "maintenance selftest" command now takes an optional argument to
954 filter the tests to be run.
956 * The "enable", and "disable" commands now accept a range of
957 breakpoint locations, e.g. "enable 1.3-5".
962 Set and show the current working directory for the inferior.
965 Set and show compilation command used for compiling and injecting code
966 with the 'compile' commands.
968 set debug separate-debug-file
969 show debug separate-debug-file
970 Control the display of debug output about separate debug file search.
972 set dump-excluded-mappings
973 show dump-excluded-mappings
974 Control whether mappings marked with the VM_DONTDUMP flag should be
975 dumped when generating a core file.
978 List the registered selftests.
981 Start the debugged program stopping at the first instruction.
984 Control display of debugging messages related to OpenRISC targets.
986 set|show print type nested-type-limit
987 Set and show the limit of nesting level for nested types that the
988 type printer will show.
990 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
993 * Safer/improved support for debugging with no debug info
995 GDB no longer assumes functions with no debug information return
998 This means that GDB now refuses to call such functions unless you
999 tell it the function's type, by either casting the call to the
1000 declared return type, or by casting the function to a function
1001 pointer of the right type, and calling that:
1003 (gdb) p getenv ("PATH")
1004 'getenv' has unknown return type; cast the call to its declared return type
1005 (gdb) p (char *) getenv ("PATH")
1006 $1 = 0x7fffffffe "/usr/local/bin:/"...
1007 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1008 $2 = 0x7fffffffe "/usr/local/bin:/"...
1010 Similarly, GDB no longer assumes that global variables with no debug
1011 info have type 'int', and refuses to print the variable's value
1012 unless you tell it the variable's type:
1015 'var' has unknown type; cast it to its declared type
1019 * New native configurations
1021 FreeBSD/aarch64 aarch64*-*-freebsd*
1022 FreeBSD/arm arm*-*-freebsd*
1026 FreeBSD/aarch64 aarch64*-*-freebsd*
1027 FreeBSD/arm arm*-*-freebsd*
1028 OpenRISC ELF or1k*-*-elf
1030 * Removed targets and native configurations
1032 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1034 *** Changes in GDB 8.0
1036 * GDB now supports access to the PKU register on GNU/Linux. The register is
1037 added by the Memory Protection Keys for Userspace feature which will be
1038 available in future Intel CPUs.
1040 * GDB now supports C++11 rvalue references.
1044 ** New functions to start, stop and access a running btrace recording.
1045 ** Rvalue references are now supported in gdb.Type.
1047 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1050 * Building GDB and GDBserver now requires a C++11 compiler.
1052 For example, GCC 4.8 or later.
1054 It is no longer possible to build GDB or GDBserver with a C
1055 compiler. The --disable-build-with-cxx configure option has been
1058 * Building GDB and GDBserver now requires GNU make >= 3.81.
1060 It is no longer supported to build GDB or GDBserver with another
1061 implementation of the make program or an earlier version of GNU make.
1063 * Native debugging on MS-Windows supports command-line redirection
1065 Command-line arguments used for starting programs on MS-Windows can
1066 now include redirection symbols supported by native Windows shells,
1067 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1068 as "run", "start", and "set args", as well as the corresponding MI
1071 * Support for thread names on MS-Windows.
1073 GDB now catches and handles the special exception that programs
1074 running on MS-Windows use to assign names to threads in the
1077 * Support for Java programs compiled with gcj has been removed.
1079 * User commands now accept an unlimited number of arguments.
1080 Previously, only up to 10 was accepted.
1082 * The "eval" command now expands user-defined command arguments.
1084 This makes it easier to process a variable number of arguments:
1089 eval "print $arg%d", $i
1094 * Target descriptions can now describe registers for sparc32 and sparc64.
1096 * GDB now supports DWARF version 5 (debug information format).
1097 Its .debug_names index is not yet supported.
1099 * New native configurations
1101 FreeBSD/mips mips*-*-freebsd
1105 Synopsys ARC arc*-*-elf32
1106 FreeBSD/mips mips*-*-freebsd
1108 * Removed targets and native configurations
1110 Alpha running FreeBSD alpha*-*-freebsd*
1111 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1116 Erases all the flash memory regions reported by the target.
1118 maint print arc arc-instruction address
1119 Print internal disassembler information about instruction at a given address.
1123 set disassembler-options
1124 show disassembler-options
1125 Controls the passing of target specific information to the disassembler.
1126 If it is necessary to specify more than one disassembler option then
1127 multiple options can be placed together into a comma separated list.
1128 The default value is the empty string. Currently, the only supported
1129 targets are ARM, PowerPC and S/390.
1134 Erases all the flash memory regions reported by the target. This is
1135 equivalent to the CLI command flash-erase.
1137 -file-list-shared-libraries
1138 List the shared libraries in the program. This is
1139 equivalent to the CLI command "info shared".
1142 Catchpoints stopping the program when Ada exceptions are
1143 handled. This is equivalent to the CLI command "catch handlers".
1145 *** Changes in GDB 7.12
1147 * GDB and GDBserver now build with a C++ compiler by default.
1149 The --enable-build-with-cxx configure option is now enabled by
1150 default. One must now explicitly configure with
1151 --disable-build-with-cxx in order to build with a C compiler. This
1152 option will be removed in a future release.
1154 * GDBserver now supports recording btrace without maintaining an active
1157 * GDB now supports a negative repeat count in the 'x' command to examine
1158 memory backward from the given address. For example:
1161 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1162 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1163 (gdb) x/-5i 0x0000000000400580
1164 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1165 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1166 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1167 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1168 0x40057b <main(int, char**)+25>:
1169 callq 0x400536 <Func1(int, char const*)>
1171 * Fortran: Support structures with fields of dynamic types and
1172 arrays of dynamic types.
1174 * The symbol dumping maintenance commands have new syntax.
1175 maint print symbols [-pc address] [--] [filename]
1176 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1177 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1178 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1179 maint print msymbols [-objfile objfile] [--] [filename]
1181 * GDB now supports multibit bitfields and enums in target register
1184 * New Python-based convenience function $_as_string(val), which returns
1185 the textual representation of a value. This function is especially
1186 useful to obtain the text label of an enum value.
1188 * Intel MPX bound violation handling.
1190 Segmentation faults caused by a Intel MPX boundary violation
1191 now display the kind of violation (upper or lower), the memory
1192 address accessed and the memory bounds, along with the usual
1193 signal received and code location.
1197 Program received signal SIGSEGV, Segmentation fault
1198 Upper bound violation while accessing address 0x7fffffffc3b3
1199 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1200 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1202 * Rust language support.
1203 GDB now supports debugging programs written in the Rust programming
1204 language. See https://www.rust-lang.org/ for more information about
1207 * Support for running interpreters on specified input/output devices
1209 GDB now supports a new mechanism that allows frontends to provide
1210 fully featured GDB console views, as a better alternative to
1211 building such views on top of the "-interpreter-exec console"
1212 command. See the new "new-ui" command below. With that command,
1213 frontends can now start GDB in the traditional command-line mode
1214 running in an embedded terminal emulator widget, and create a
1215 separate MI interpreter running on a specified i/o device. In this
1216 way, GDB handles line editing, history, tab completion, etc. in the
1217 console all by itself, and the GUI uses the separate MI interpreter
1218 for its own control and synchronization, invisible to the command
1221 * The "catch syscall" command catches groups of related syscalls.
1223 The "catch syscall" command now supports catching a group of related
1224 syscalls using the 'group:' or 'g:' prefix.
1229 skip -gfile file-glob-pattern
1230 skip -function function
1231 skip -rfunction regular-expression
1232 A generalized form of the skip command, with new support for
1233 glob-style file names and regular expressions for function names.
1234 Additionally, a file spec and a function spec may now be combined.
1236 maint info line-table REGEXP
1237 Display the contents of GDB's internal line table data struture.
1240 Run any GDB unit tests that were compiled in.
1243 Start a new user interface instance running INTERP as interpreter,
1244 using the TTY file for input/output.
1248 ** gdb.Breakpoint objects have a new attribute "pending", which
1249 indicates whether the breakpoint is pending.
1250 ** Three new breakpoint-related events have been added:
1251 gdb.breakpoint_created, gdb.breakpoint_modified, and
1252 gdb.breakpoint_deleted.
1254 signal-event EVENTID
1255 Signal ("set") the given MS-Windows event object. This is used in
1256 conjunction with the Windows JIT debugging (AeDebug) support, where
1257 the OS suspends a crashing process until a debugger can attach to
1258 it. Resuming the crashing process, in order to debug it, is done by
1259 signalling an event.
1261 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1262 was added in GDBserver, including JIT compiling fast tracepoint's
1263 conditional expression bytecode into native code.
1265 * Support for various remote target protocols and ROM monitors has
1268 target m32rsdi Remote M32R debugging over SDI
1269 target mips MIPS remote debugging protocol
1270 target pmon PMON ROM monitor
1271 target ddb NEC's DDB variant of PMON for Vr4300
1272 target rockhopper NEC RockHopper variant of PMON
1273 target lsi LSI variant of PMO
1275 * Support for tracepoints and fast tracepoints on powerpc-linux,
1276 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1277 including JIT compiling fast tracepoint's conditional expression
1278 bytecode into native code.
1280 * MI async record =record-started now includes the method and format used for
1281 recording. For example:
1283 =record-started,thread-group="i1",method="btrace",format="bts"
1285 * MI async record =thread-selected now includes the frame field. For example:
1287 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1291 Andes NDS32 nds32*-*-elf
1293 *** Changes in GDB 7.11
1295 * GDB now supports debugging kernel-based threads on FreeBSD.
1297 * Per-inferior thread numbers
1299 Thread numbers are now per inferior instead of global. If you're
1300 debugging multiple inferiors, GDB displays thread IDs using a
1301 qualified INF_NUM.THR_NUM form. For example:
1305 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1306 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1307 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1308 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1310 As consequence, thread numbers as visible in the $_thread
1311 convenience variable and in Python's InferiorThread.num attribute
1312 are no longer unique between inferiors.
1314 GDB now maintains a second thread ID per thread, referred to as the
1315 global thread ID, which is the new equivalent of thread numbers in
1316 previous releases. See also $_gthread below.
1318 For backwards compatibility, MI's thread IDs always refer to global
1321 * Commands that accept thread IDs now accept the qualified
1322 INF_NUM.THR_NUM form as well. For example:
1325 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1328 * In commands that accept a list of thread IDs, you can now refer to
1329 all threads of an inferior using a star wildcard. GDB accepts
1330 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1331 refer to all threads of the current inferior. For example, "info
1334 * You can use "info threads -gid" to display the global thread ID of
1337 * The new convenience variable $_gthread holds the global number of
1340 * The new convenience variable $_inferior holds the number of the
1343 * GDB now displays the ID and name of the thread that hit a breakpoint
1344 or received a signal, if your program is multi-threaded. For
1347 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1348 Thread 1 "main" received signal SIGINT, Interrupt.
1350 * Record btrace now supports non-stop mode.
1352 * Support for tracepoints on aarch64-linux was added in GDBserver.
1354 * The 'record instruction-history' command now indicates speculative execution
1355 when using the Intel Processor Trace recording format.
1357 * GDB now allows users to specify explicit locations, bypassing
1358 the linespec parser. This feature is also available to GDB/MI
1361 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1362 GDB now is able to debug both AArch64 applications and ARM applications
1365 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1366 including JIT compiling fast tracepoint's conditional expression bytecode
1369 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1371 * "info threads", "info inferiors", "info display", "info checkpoints"
1372 and "maint info program-spaces" now list the corresponding items in
1373 ascending ID order, for consistency with all other "info" commands.
1375 * In Ada, the overloads selection menu has been enhanced to display the
1376 parameter types and the return types for the matching overloaded subprograms.
1380 maint set target-non-stop (on|off|auto)
1381 maint show target-non-stop
1382 Control whether GDB targets always operate in non-stop mode even if
1383 "set non-stop" is "off". The default is "auto", meaning non-stop
1384 mode is enabled if supported by the target.
1386 maint set bfd-sharing
1387 maint show bfd-sharing
1388 Control the reuse of bfd objects.
1391 show debug bfd-cache
1392 Control display of debugging info regarding bfd caching.
1396 Control display of debugging info regarding FreeBSD threads.
1398 set remote multiprocess-extensions-packet
1399 show remote multiprocess-extensions-packet
1400 Set/show the use of the remote protocol multiprocess extensions.
1402 set remote thread-events
1403 show remote thread-events
1404 Set/show the use of thread create/exit events.
1406 set ada print-signatures on|off
1407 show ada print-signatures"
1408 Control whether parameter types and return types are displayed in overloads
1409 selection menus. It is activaled (@code{on}) by default.
1413 Controls the maximum size of memory, in bytes, that GDB will
1414 allocate for value contents. Prevents incorrect programs from
1415 causing GDB to allocate overly large buffers. Default is 64k.
1417 * The "disassemble" command accepts a new modifier: /s.
1418 It prints mixed source+disassembly like /m with two differences:
1419 - disassembled instructions are now printed in program order, and
1420 - and source for all relevant files is now printed.
1421 The "/m" option is now considered deprecated: its "source-centric"
1422 output hasn't proved useful in practice.
1424 * The "record instruction-history" command accepts a new modifier: /s.
1425 It behaves exactly like /m and prints mixed source+disassembly.
1427 * The "set scheduler-locking" command supports a new mode "replay".
1428 It behaves like "off" in record mode and like "on" in replay mode.
1430 * Support for various ROM monitors has been removed:
1432 target dbug dBUG ROM monitor for Motorola ColdFire
1433 target picobug Motorola picobug monitor
1434 target dink32 DINK32 ROM monitor for PowerPC
1435 target m32r Renesas M32R/D ROM monitor
1436 target mon2000 mon2000 ROM monitor
1437 target ppcbug PPCBUG ROM monitor for PowerPC
1439 * Support for reading/writing memory and extracting values on architectures
1440 whose memory is addressable in units of any integral multiple of 8 bits.
1443 Allows to break when an Ada exception is handled.
1445 * New remote packets
1448 Indicates that an exec system call was executed.
1450 exec-events feature in qSupported
1451 The qSupported packet allows GDB to request support for exec
1452 events using the new 'gdbfeature' exec-event, and the qSupported
1453 response can contain the corresponding 'stubfeature'. Set and
1454 show commands can be used to display whether these features are enabled.
1457 Equivalent to interrupting with the ^C character, but works in
1460 thread created stop reason (T05 create:...)
1461 Indicates that the thread was just created and is stopped at entry.
1463 thread exit stop reply (w exitcode;tid)
1464 Indicates that the thread has terminated.
1467 Enables/disables thread create and exit event reporting. For
1468 example, this is used in non-stop mode when GDB stops a set of
1469 threads and synchronously waits for the their corresponding stop
1470 replies. Without exit events, if one of the threads exits, GDB
1471 would hang forever not knowing that it should no longer expect a
1472 stop for that same thread.
1475 Indicates that there are no resumed threads left in the target (all
1476 threads are stopped). The remote stub reports support for this stop
1477 reply to GDB's qSupported query.
1480 Enables/disables catching syscalls from the inferior process.
1481 The remote stub reports support for this packet to GDB's qSupported query.
1483 syscall_entry stop reason
1484 Indicates that a syscall was just called.
1486 syscall_return stop reason
1487 Indicates that a syscall just returned.
1489 * Extended-remote exec events
1491 ** GDB now has support for exec events on extended-remote Linux targets.
1492 For such targets with Linux kernels 2.5.46 and later, this enables
1493 follow-exec-mode and exec catchpoints.
1495 set remote exec-event-feature-packet
1496 show remote exec-event-feature-packet
1497 Set/show the use of the remote exec event feature.
1499 * Thread names in remote protocol
1501 The reply to qXfer:threads:read may now include a name attribute for each
1504 * Target remote mode fork and exec events
1506 ** GDB now has support for fork and exec events on target remote mode
1507 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1508 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1509 fork and exec catchpoints.
1511 * Remote syscall events
1513 ** GDB now has support for catch syscall on remote Linux targets,
1514 currently enabled on x86/x86_64 architectures.
1516 set remote catch-syscall-packet
1517 show remote catch-syscall-packet
1518 Set/show the use of the remote catch syscall feature.
1522 ** The -var-set-format command now accepts the zero-hexadecimal
1523 format. It outputs data in hexadecimal format with zero-padding on the
1528 ** gdb.InferiorThread objects have a new attribute "global_num",
1529 which refers to the thread's global thread ID. The existing
1530 "num" attribute now refers to the thread's per-inferior number.
1531 See "Per-inferior thread numbers" above.
1532 ** gdb.InferiorThread objects have a new attribute "inferior", which
1533 is the Inferior object the thread belongs to.
1535 *** Changes in GDB 7.10
1537 * Support for process record-replay and reverse debugging on aarch64*-linux*
1538 targets has been added. GDB now supports recording of A64 instruction set
1539 including advance SIMD instructions.
1541 * Support for Sun's version of the "stabs" debug file format has been removed.
1543 * GDB now honors the content of the file /proc/PID/coredump_filter
1544 (PID is the process ID) on GNU/Linux systems. This file can be used
1545 to specify the types of memory mappings that will be included in a
1546 corefile. For more information, please refer to the manual page of
1547 "core(5)". GDB also has a new command: "set use-coredump-filter
1548 on|off". It allows to set whether GDB will read the content of the
1549 /proc/PID/coredump_filter file when generating a corefile.
1551 * The "info os" command on GNU/Linux can now display information on
1553 "info os cpus" Listing of all cpus/cores on the system
1555 * GDB has two new commands: "set serial parity odd|even|none" and
1556 "show serial parity". These allows to set or show parity for the
1559 * The "info source" command now displays the producer string if it was
1560 present in the debug info. This typically includes the compiler version
1561 and may include things like its command line arguments.
1563 * The "info dll", an alias of the "info sharedlibrary" command,
1564 is now available on all platforms.
1566 * Directory names supplied to the "set sysroot" commands may be
1567 prefixed with "target:" to tell GDB to access shared libraries from
1568 the target system, be it local or remote. This replaces the prefix
1569 "remote:". The default sysroot has been changed from "" to
1570 "target:". "remote:" is automatically converted to "target:" for
1571 backward compatibility.
1573 * The system root specified by "set sysroot" will be prepended to the
1574 filename of the main executable (if reported to GDB as absolute by
1575 the operating system) when starting processes remotely, and when
1576 attaching to already-running local or remote processes.
1578 * GDB now supports automatic location and retrieval of executable
1579 files from remote targets. Remote debugging can now be initiated
1580 using only a "target remote" or "target extended-remote" command
1581 (no "set sysroot" or "file" commands are required). See "New remote
1584 * The "dump" command now supports verilog hex format.
1586 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1588 * On GNU/Linux, GDB and gdbserver are now able to access executable
1589 and shared library files without a "set sysroot" command when
1590 attaching to processes running in different mount namespaces from
1591 the debugger. This makes it possible to attach to processes in
1592 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1593 See "New remote packets" below.
1595 * The "tui reg" command now provides completion for all of the
1596 available register groups, including target specific groups.
1598 * The HISTSIZE environment variable is no longer read when determining
1599 the size of GDB's command history. GDB now instead reads the dedicated
1600 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1601 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1606 ** Memory ports can now be unbuffered.
1610 ** gdb.Objfile objects have a new attribute "username",
1611 which is the name of the objfile as specified by the user,
1612 without, for example, resolving symlinks.
1613 ** You can now write frame unwinders in Python.
1614 ** gdb.Type objects have a new method "optimized_out",
1615 returning optimized out gdb.Value instance of this type.
1616 ** gdb.Value objects have new methods "reference_value" and
1617 "const_value" which return a reference to the value and a
1618 "const" version of the value respectively.
1622 maint print symbol-cache
1623 Print the contents of the symbol cache.
1625 maint print symbol-cache-statistics
1626 Print statistics of symbol cache usage.
1628 maint flush-symbol-cache
1629 Flush the contents of the symbol cache.
1633 Start branch trace recording using Branch Trace Store (BTS) format.
1636 Evaluate expression by using the compiler and print result.
1640 Explicit commands for enabling and disabling tui mode.
1643 set mpx bound on i386 and amd64
1644 Support for bound table investigation on Intel MPX enabled applications.
1648 Start branch trace recording using Intel Processor Trace format.
1651 Print information about branch tracing internals.
1653 maint btrace packet-history
1654 Print the raw branch tracing data.
1656 maint btrace clear-packet-history
1657 Discard the stored raw branch tracing data.
1660 Discard all branch tracing data. It will be fetched and processed
1661 anew by the next "record" command.
1666 Renamed from "set debug dwarf2-die".
1667 show debug dwarf-die
1668 Renamed from "show debug dwarf2-die".
1670 set debug dwarf-read
1671 Renamed from "set debug dwarf2-read".
1672 show debug dwarf-read
1673 Renamed from "show debug dwarf2-read".
1675 maint set dwarf always-disassemble
1676 Renamed from "maint set dwarf2 always-disassemble".
1677 maint show dwarf always-disassemble
1678 Renamed from "maint show dwarf2 always-disassemble".
1680 maint set dwarf max-cache-age
1681 Renamed from "maint set dwarf2 max-cache-age".
1682 maint show dwarf max-cache-age
1683 Renamed from "maint show dwarf2 max-cache-age".
1685 set debug dwarf-line
1686 show debug dwarf-line
1687 Control display of debugging info regarding DWARF line processing.
1690 show max-completions
1691 Set the maximum number of candidates to be considered during
1692 completion. The default value is 200. This limit allows GDB
1693 to avoid generating large completion lists, the computation of
1694 which can cause the debugger to become temporarily unresponsive.
1696 set history remove-duplicates
1697 show history remove-duplicates
1698 Control the removal of duplicate history entries.
1700 maint set symbol-cache-size
1701 maint show symbol-cache-size
1702 Control the size of the symbol cache.
1704 set|show record btrace bts buffer-size
1705 Set and show the size of the ring buffer used for branch tracing in
1707 The obtained size may differ from the requested size. Use "info
1708 record" to see the obtained buffer size.
1710 set debug linux-namespaces
1711 show debug linux-namespaces
1712 Control display of debugging info regarding Linux namespaces.
1714 set|show record btrace pt buffer-size
1715 Set and show the size of the ring buffer used for branch tracing in
1716 Intel Processor Trace format.
1717 The obtained size may differ from the requested size. Use "info
1718 record" to see the obtained buffer size.
1720 maint set|show btrace pt skip-pad
1721 Set and show whether PAD packets are skipped when computing the
1724 * The command 'thread apply all' can now support new option '-ascending'
1725 to call its specified command for all threads in ascending order.
1727 * Python/Guile scripting
1729 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1730 special section named `.debug_gdb_scripts'.
1732 * New remote packets
1734 qXfer:btrace-conf:read
1735 Return the branch trace configuration for the current thread.
1737 Qbtrace-conf:bts:size
1738 Set the requested ring buffer size for branch tracing in BTS format.
1741 Enable Intel Procesor Trace-based branch tracing for the current
1742 process. The remote stub reports support for this packet to GDB's
1745 Qbtrace-conf:pt:size
1746 Set the requested ring buffer size for branch tracing in Intel Processor
1750 Indicates a memory breakpoint instruction was executed, irrespective
1751 of whether it was GDB that planted the breakpoint or the breakpoint
1752 is hardcoded in the program. This is required for correct non-stop
1756 Indicates the target stopped for a hardware breakpoint. This is
1757 required for correct non-stop mode operation.
1760 Return information about files on the remote system.
1762 qXfer:exec-file:read
1763 Return the full absolute name of the file that was executed to
1764 create a process running on the remote system.
1767 Select the filesystem on which vFile: operations with filename
1768 arguments will operate. This is required for GDB to be able to
1769 access files on remote targets where the remote stub does not
1770 share a common filesystem with the inferior(s).
1773 Indicates that a fork system call was executed.
1776 Indicates that a vfork system call was executed.
1778 vforkdone stop reason
1779 Indicates that a vfork child of the specified process has executed
1780 an exec or exit, allowing the vfork parent to resume execution.
1782 fork-events and vfork-events features in qSupported
1783 The qSupported packet allows GDB to request support for fork and
1784 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1785 and the qSupported response can contain the corresponding
1786 'stubfeatures'. Set and show commands can be used to display
1787 whether these features are enabled.
1789 * Extended-remote fork events
1791 ** GDB now has support for fork events on extended-remote Linux
1792 targets. For targets with Linux kernels 2.5.60 and later, this
1793 enables follow-fork-mode and detach-on-fork for both fork and
1794 vfork, as well as fork and vfork catchpoints.
1796 * The info record command now shows the recording format and the
1797 branch tracing configuration for the current thread when using
1798 the btrace record target.
1799 For the BTS format, it shows the ring buffer size.
1801 * GDB now has support for DTrace USDT (Userland Static Defined
1802 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1804 * GDB now supports access to vector registers on S/390 GNU/Linux
1807 * Removed command line options
1809 -xdb HP-UX XDB compatibility mode.
1811 * Removed targets and native configurations
1813 HP/PA running HP-UX hppa*-*-hpux*
1814 Itanium running HP-UX ia64-*-hpux*
1816 * New configure options
1819 This configure option allows the user to build GDB with support for
1820 Intel Processor Trace (default: auto). This requires libipt.
1822 --with-libipt-prefix=PATH
1823 Specify the path to the version of libipt that GDB should use.
1824 $PATH/include should contain the intel-pt.h header and
1825 $PATH/lib should contain the libipt.so library.
1827 *** Changes in GDB 7.9.1
1831 ** Xmethods can now specify a result type.
1833 *** Changes in GDB 7.9
1835 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1839 ** You can now access frame registers from Python scripts.
1840 ** New attribute 'producer' for gdb.Symtab objects.
1841 ** gdb.Objfile objects have a new attribute "progspace",
1842 which is the gdb.Progspace object of the containing program space.
1843 ** gdb.Objfile objects have a new attribute "owner".
1844 ** gdb.Objfile objects have a new attribute "build_id",
1845 which is the build ID generated when the file was built.
1846 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1847 ** A new event "gdb.clear_objfiles" has been added, triggered when
1848 selecting a new file to debug.
1849 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1850 ** New function gdb.lookup_objfile.
1852 New events which are triggered when GDB modifies the state of the
1855 ** gdb.events.inferior_call_pre: Function call is about to be made.
1856 ** gdb.events.inferior_call_post: Function call has just been made.
1857 ** gdb.events.memory_changed: A memory location has been altered.
1858 ** gdb.events.register_changed: A register has been altered.
1860 * New Python-based convenience functions:
1862 ** $_caller_is(name [, number_of_frames])
1863 ** $_caller_matches(regexp [, number_of_frames])
1864 ** $_any_caller_is(name [, number_of_frames])
1865 ** $_any_caller_matches(regexp [, number_of_frames])
1867 * GDB now supports the compilation and injection of source code into
1868 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1869 to compile the source code to object code, and if successful, inject
1870 and execute that code within the current context of the inferior.
1871 Currently the C language is supported. The commands used to
1872 interface with this new feature are:
1874 compile code [-raw|-r] [--] [source code]
1875 compile file [-raw|-r] filename
1879 demangle [-l language] [--] name
1880 Demangle "name" in the specified language, or the current language
1881 if elided. This command is renamed from the "maint demangle" command.
1882 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1883 as "maint demangler-warning".
1885 queue-signal signal-name-or-number
1886 Queue a signal to be delivered to the thread when it is resumed.
1888 add-auto-load-scripts-directory directory
1889 Add entries to the list of directories from which to load auto-loaded
1892 maint print user-registers
1893 List all currently available "user" registers.
1895 compile code [-r|-raw] [--] [source code]
1896 Compile, inject, and execute in the inferior the executable object
1897 code produced by compiling the provided source code.
1899 compile file [-r|-raw] filename
1900 Compile and inject into the inferior the executable object code
1901 produced by compiling the source code stored in the filename
1904 * On resume, GDB now always passes the signal the program had stopped
1905 for to the thread the signal was sent to, even if the user changed
1906 threads before resuming. Previously GDB would often (but not
1907 always) deliver the signal to the thread that happens to be current
1910 * Conversely, the "signal" command now consistently delivers the
1911 requested signal to the current thread. GDB now asks for
1912 confirmation if the program had stopped for a signal and the user
1913 switched threads meanwhile.
1915 * "breakpoint always-inserted" modes "off" and "auto" merged.
1917 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1918 won't remove breakpoints from the target until all threads stop,
1919 even in non-stop mode. The "auto" mode has been removed, and "off"
1920 is now the default mode.
1924 set debug symbol-lookup
1925 show debug symbol-lookup
1926 Control display of debugging info regarding symbol lookup.
1930 ** The -list-thread-groups command outputs an exit-code field for
1931 inferiors that have exited.
1935 MIPS SDE mips*-sde*-elf*
1939 Support for these obsolete configurations has been removed.
1941 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1942 SGI Irix-5.x mips-*-irix5*
1943 SGI Irix-6.x mips-*-irix6*
1944 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1945 VAX running Ultrix vax-*-ultrix*
1947 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1948 and "assf"), have been removed. Use the "sharedlibrary" command, or
1949 its alias "share", instead.
1951 *** Changes in GDB 7.8
1953 * New command line options
1956 This is an alias for the --data-directory option.
1958 * GDB supports printing and modifying of variable length automatic arrays
1959 as specified in ISO C99.
1961 * The ARM simulator now supports instruction level tracing
1962 with or without disassembly.
1966 GDB now has support for scripting using Guile. Whether this is
1967 available is determined at configure time.
1968 Guile version 2.0 or greater is required.
1969 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1971 * New commands (for set/show, see "New options" below)
1975 Invoke CODE by passing it to the Guile interpreter.
1979 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1981 info auto-load guile-scripts [regexp]
1982 Print the list of automatically loaded Guile scripts.
1984 * The source command is now capable of sourcing Guile scripts.
1985 This feature is dependent on the debugger being built with Guile support.
1989 set print symbol-loading (off|brief|full)
1990 show print symbol-loading
1991 Control whether to print informational messages when loading symbol
1992 information for a file. The default is "full", but when debugging
1993 programs with large numbers of shared libraries the amount of output
1994 becomes less useful.
1996 set guile print-stack (none|message|full)
1997 show guile print-stack
1998 Show a stack trace when an error is encountered in a Guile script.
2000 set auto-load guile-scripts (on|off)
2001 show auto-load guile-scripts
2002 Control auto-loading of Guile script files.
2004 maint ada set ignore-descriptive-types (on|off)
2005 maint ada show ignore-descriptive-types
2006 Control whether the debugger should ignore descriptive types in Ada
2007 programs. The default is not to ignore the descriptive types. See
2008 the user manual for more details on descriptive types and the intended
2009 usage of this option.
2011 set auto-connect-native-target
2013 Control whether GDB is allowed to automatically connect to the
2014 native target for the run, attach, etc. commands when not connected
2015 to any target yet. See also "target native" below.
2017 set record btrace replay-memory-access (read-only|read-write)
2018 show record btrace replay-memory-access
2019 Control what memory accesses are allowed during replay.
2021 maint set target-async (on|off)
2022 maint show target-async
2023 This controls whether GDB targets operate in synchronous or
2024 asynchronous mode. Normally the default is asynchronous, if it is
2025 available; but this can be changed to more easily debug problems
2026 occurring only in synchronous mode.
2028 set mi-async (on|off)
2030 Control whether MI asynchronous mode is preferred. This supersedes
2031 "set target-async" of previous GDB versions.
2033 * "set target-async" is deprecated as a CLI option and is now an alias
2034 for "set mi-async" (only puts MI into async mode).
2036 * Background execution commands (e.g., "c&", "s&", etc.) are now
2037 possible ``out of the box'' if the target supports them. Previously
2038 the user would need to explicitly enable the possibility with the
2039 "set target-async on" command.
2041 * New features in the GDB remote stub, GDBserver
2043 ** New option --debug-format=option1[,option2,...] allows one to add
2044 additional text to each output. At present only timestamps
2045 are supported: --debug-format=timestamps.
2046 Timestamps can also be turned on with the
2047 "monitor set debug-format timestamps" command from GDB.
2049 * The 'record instruction-history' command now starts counting instructions
2050 at one. This also affects the instruction ranges reported by the
2051 'record function-call-history' command when given the /i modifier.
2053 * The command 'record function-call-history' supports a new modifier '/c' to
2054 indent the function names based on their call stack depth.
2055 The fields for the '/i' and '/l' modifier have been reordered.
2056 The source line range is now prefixed with 'at'.
2057 The instruction range is now prefixed with 'inst'.
2058 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2059 "record instruction-history" and "list" commands.
2061 * The ranges given as arguments to the 'record function-call-history' and
2062 'record instruction-history' commands are now inclusive.
2064 * The btrace record target now supports the 'record goto' command.
2065 For locations inside the execution trace, the back trace is computed
2066 based on the information stored in the execution trace.
2068 * The btrace record target supports limited reverse execution and replay.
2069 The target does not record data and therefore does not allow reading
2070 memory or registers.
2072 * The "catch syscall" command now works on s390*-linux* targets.
2074 * The "compare-sections" command is no longer specific to target
2075 remote. It now works with all targets.
2077 * All native targets are now consistently called "native".
2078 Consequently, the "target child", "target GNU", "target djgpp",
2079 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2080 commands have been replaced with "target native". The QNX/NTO port
2081 leaves the "procfs" target in place and adds a "native" target for
2082 consistency with other ports. The impact on users should be minimal
2083 as these commands previously either throwed an error, or were
2084 no-ops. The target's name is visible in the output of the following
2085 commands: "help target", "info target", "info files", "maint print
2088 * The "target native" command now connects to the native target. This
2089 can be used to launch native programs even when "set
2090 auto-connect-native-target" is set to off.
2092 * GDB now supports access to Intel MPX registers on GNU/Linux.
2094 * Support for Intel AVX-512 registers on GNU/Linux.
2095 Support displaying and modifying Intel AVX-512 registers
2096 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2098 * New remote packets
2100 qXfer:btrace:read's annex
2101 The qXfer:btrace:read packet supports a new annex 'delta' to read
2102 branch trace incrementally.
2106 ** Valid Python operations on gdb.Value objects representing
2107 structs/classes invoke the corresponding overloaded operators if
2109 ** New `Xmethods' feature in the Python API. Xmethods are
2110 additional methods or replacements for existing methods of a C++
2111 class. This feature is useful for those cases where a method
2112 defined in C++ source code could be inlined or optimized out by
2113 the compiler, making it unavailable to GDB.
2116 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2118 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2119 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2120 its alias "share", instead.
2122 * The commands "set remotebaud" and "show remotebaud" are no longer
2123 supported. Use "set serial baud" and "show serial baud" (respectively)
2128 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2129 target-async". The latter is left as a deprecated alias of the
2130 former for backward compatibility. If the target supports it,
2131 CLI background execution commands are now always possible by
2132 default, independently of whether the frontend stated a
2133 preference for asynchronous execution with "-gdb-set mi-async".
2134 Previously "-gdb-set target-async off" affected both MI execution
2135 commands and CLI execution commands.
2137 *** Changes in GDB 7.7
2139 * Improved support for process record-replay and reverse debugging on
2140 arm*-linux* targets. Support for thumb32 and syscall instruction
2141 recording has been added.
2143 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2145 * GDB now supports Fission DWP file format version 2.
2146 http://gcc.gnu.org/wiki/DebugFission
2148 * New convenience function "$_isvoid", to check whether an expression
2149 is void. A void expression is an expression where the type of the
2150 result is "void". For example, some convenience variables may be
2151 "void" when evaluated (e.g., "$_exitcode" before the execution of
2152 the program being debugged; or an undefined convenience variable).
2153 Another example, when calling a function whose return type is
2156 * The "maintenance print objfiles" command now takes an optional regexp.
2158 * The "catch syscall" command now works on arm*-linux* targets.
2160 * GDB now consistently shows "<not saved>" when printing values of
2161 registers the debug info indicates have not been saved in the frame
2162 and there's nowhere to retrieve them from
2163 (callee-saved/call-clobbered registers):
2168 (gdb) info registers rax
2171 Before, the former would print "<optimized out>", and the latter
2172 "*value not available*".
2174 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2179 ** Frame filters and frame decorators have been added.
2180 ** Temporary breakpoints are now supported.
2181 ** Line tables representation has been added.
2182 ** New attribute 'parent_type' for gdb.Field objects.
2183 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2184 ** New attribute 'name' for gdb.Type objects.
2188 Nios II ELF nios2*-*-elf
2189 Nios II GNU/Linux nios2*-*-linux
2190 Texas Instruments MSP430 msp430*-*-elf
2192 * Removed native configurations
2194 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2195 been removed. ELF variants of these configurations are kept supported.
2197 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2198 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2199 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2200 i[34567]86-*-openbsd3.[0-3]
2201 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2202 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2203 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2207 Like "catch throw", but catches a re-thrown exception.
2208 maint check-psymtabs
2209 Renamed from old "maint check-symtabs".
2211 Perform consistency checks on symtabs.
2212 maint expand-symtabs
2213 Expand symtabs matching an optional regexp.
2216 Display the details of GDB configure-time options.
2218 maint set|show per-command
2219 maint set|show per-command space
2220 maint set|show per-command time
2221 maint set|show per-command symtab
2222 Enable display of per-command gdb resource usage.
2224 remove-symbol-file FILENAME
2225 remove-symbol-file -a ADDRESS
2226 Remove a symbol file added via add-symbol-file. The file to remove
2227 can be identified by its filename or by an address that lies within
2228 the boundaries of this symbol file in memory.
2231 info exceptions REGEXP
2232 Display the list of Ada exceptions defined in the program being
2233 debugged. If provided, only the exceptions whose names match REGEXP
2238 set debug symfile off|on
2240 Control display of debugging info regarding reading symbol files and
2241 symbol tables within those files
2243 set print raw frame-arguments
2244 show print raw frame-arguments
2245 Set/show whether to print frame arguments in raw mode,
2246 disregarding any defined pretty-printers.
2248 set remote trace-status-packet
2249 show remote trace-status-packet
2250 Set/show the use of remote protocol qTStatus packet.
2254 Control display of debugging messages related to Nios II targets.
2258 Control whether target-assisted range stepping is enabled.
2260 set startup-with-shell
2261 show startup-with-shell
2262 Specifies whether Unix child processes are started via a shell or
2267 Use the target memory cache for accesses to the code segment. This
2268 improves performance of remote debugging (particularly disassembly).
2270 * You can now use a literal value 'unlimited' for options that
2271 interpret 0 or -1 as meaning "unlimited". E.g., "set
2272 trace-buffer-size unlimited" is now an alias for "set
2273 trace-buffer-size -1" and "set height unlimited" is now an alias for
2276 * The "set debug symtab-create" debugging option of GDB has been changed to
2277 accept a verbosity level. 0 means "off", 1 provides basic debugging
2278 output, and values of 2 or greater provides more verbose output.
2280 * New command-line options
2282 Display the details of GDB configure-time options.
2284 * The command 'tsave' can now support new option '-ctf' to save trace
2285 buffer in Common Trace Format.
2287 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2290 * GDB now implements the the C++ 'typeid' operator.
2292 * The new convenience variable $_exception holds the exception being
2293 thrown or caught at an exception-related catchpoint.
2295 * The exception-related catchpoints, like "catch throw", now accept a
2296 regular expression which can be used to filter exceptions by type.
2298 * The new convenience variable $_exitsignal is automatically set to
2299 the terminating signal number when the program being debugged dies
2300 due to an uncaught signal.
2304 ** All MI commands now accept an optional "--language" option.
2305 Support for this feature can be verified by using the "-list-features"
2306 command, which should contain "language-option".
2308 ** The new command -info-gdb-mi-command allows the user to determine
2309 whether a GDB/MI command is supported or not.
2311 ** The "^error" result record returned when trying to execute an undefined
2312 GDB/MI command now provides a variable named "code" whose content is the
2313 "undefined-command" error code. Support for this feature can be verified
2314 by using the "-list-features" command, which should contain
2315 "undefined-command-error-code".
2317 ** The -trace-save MI command can optionally save trace buffer in Common
2320 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2322 ** The command -data-list-register-values now accepts an optional
2323 "--skip-unavailable" option. When used, only the available registers
2326 ** The new command -trace-frame-collected dumps collected variables,
2327 computed expressions, tvars, memory and registers in a traceframe.
2329 ** The commands -stack-list-locals, -stack-list-arguments and
2330 -stack-list-variables now accept an option "--skip-unavailable".
2331 When used, only the available locals or arguments are displayed.
2333 ** The -exec-run command now accepts an optional "--start" option.
2334 When used, the command follows the same semantics as the "start"
2335 command, stopping the program's execution at the start of its
2336 main subprogram. Support for this feature can be verified using
2337 the "-list-features" command, which should contain
2338 "exec-run-start-option".
2340 ** The new commands -catch-assert and -catch-exceptions insert
2341 catchpoints stopping the program when Ada exceptions are raised.
2343 ** The new command -info-ada-exceptions provides the equivalent of
2344 the new "info exceptions" command.
2346 * New system-wide configuration scripts
2347 A GDB installation now provides scripts suitable for use as system-wide
2348 configuration scripts for the following systems:
2352 * GDB now supports target-assigned range stepping with remote targets.
2353 This improves the performance of stepping source lines by reducing
2354 the number of control packets from/to GDB. See "New remote packets"
2357 * GDB now understands the element 'tvar' in the XML traceframe info.
2358 It has the id of the collected trace state variables.
2360 * On S/390 targets that provide the transactional-execution feature,
2361 the program interruption transaction diagnostic block (TDB) is now
2362 represented as a number of additional "registers" in GDB.
2364 * New remote packets
2368 The vCont packet supports a new 'r' action, that tells the remote
2369 stub to step through an address range itself, without GDB
2370 involvemement at each single-step.
2372 qXfer:libraries-svr4:read's annex
2373 The previously unused annex of the qXfer:libraries-svr4:read packet
2374 is now used to support passing an argument list. The remote stub
2375 reports support for this argument list to GDB's qSupported query.
2376 The defined arguments are "start" and "prev", used to reduce work
2377 necessary for library list updating, resulting in significant
2380 * New features in the GDB remote stub, GDBserver
2382 ** GDBserver now supports target-assisted range stepping. Currently
2383 enabled on x86/x86_64 GNU/Linux targets.
2385 ** GDBserver now adds element 'tvar' in the XML in the reply to
2386 'qXfer:traceframe-info:read'. It has the id of the collected
2387 trace state variables.
2389 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2392 * New 'z' formatter for printing and examining memory, this displays the
2393 value as hexadecimal zero padded on the left to the size of the type.
2395 * GDB can now use Windows x64 unwinding data.
2397 * The "set remotebaud" command has been replaced by "set serial baud".
2398 Similarly, "show remotebaud" has been replaced by "show serial baud".
2399 The "set remotebaud" and "show remotebaud" commands are still available
2400 to provide backward compatibility with older versions of GDB.
2402 *** Changes in GDB 7.6
2404 * Target record has been renamed to record-full.
2405 Record/replay is now enabled with the "record full" command.
2406 This also affects settings that are associated with full record/replay
2407 that have been moved from "set/show record" to "set/show record full":
2409 set|show record full insn-number-max
2410 set|show record full stop-at-limit
2411 set|show record full memory-query
2413 * A new record target "record-btrace" has been added. The new target
2414 uses hardware support to record the control-flow of a process. It
2415 does not support replaying the execution, but it implements the
2416 below new commands for investigating the recorded execution log.
2417 This new recording method can be enabled using:
2421 The "record-btrace" target is only available on Intel Atom processors
2422 and requires a Linux kernel 2.6.32 or later.
2424 * Two new commands have been added for record/replay to give information
2425 about the recorded execution without having to replay the execution.
2426 The commands are only supported by "record btrace".
2428 record instruction-history prints the execution history at
2429 instruction granularity
2431 record function-call-history prints the execution history at
2432 function granularity
2434 * New native configurations
2436 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2437 FreeBSD/powerpc powerpc*-*-freebsd
2438 x86_64/Cygwin x86_64-*-cygwin*
2439 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2443 ARM AArch64 aarch64*-*-elf
2444 ARM AArch64 GNU/Linux aarch64*-*-linux
2445 Lynx 178 PowerPC powerpc-*-lynx*178
2446 x86_64/Cygwin x86_64-*-cygwin*
2447 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2449 * If the configured location of system.gdbinit file (as given by the
2450 --with-system-gdbinit option at configure time) is in the
2451 data-directory (as specified by --with-gdb-datadir at configure
2452 time) or in one of its subdirectories, then GDB will look for the
2453 system-wide init file in the directory specified by the
2454 --data-directory command-line option.
2456 * New command line options:
2458 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2459 other initialization files, unlike -nx which disables all of them.
2461 * Removed command line options
2463 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2466 * The 'ptype' and 'whatis' commands now accept an argument to control
2469 * 'info proc' now works on some core files.
2473 ** Vectors can be created with gdb.Type.vector.
2475 ** Python's atexit.register now works in GDB.
2477 ** Types can be pretty-printed via a Python API.
2479 ** Python 3 is now supported (in addition to Python 2.4 or later)
2481 ** New class gdb.Architecture exposes GDB's internal representation
2482 of architecture in the Python API.
2484 ** New method Frame.architecture returns the gdb.Architecture object
2485 corresponding to the frame's architecture.
2487 * New Python-based convenience functions:
2489 ** $_memeq(buf1, buf2, length)
2490 ** $_streq(str1, str2)
2492 ** $_regex(str, regex)
2494 * The 'cd' command now defaults to using '~' (the home directory) if not
2497 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2498 default for GCC since November 2000.
2500 * The command 'forward-search' can now be abbreviated as 'fo'.
2502 * The command 'info tracepoints' can now display 'installed on target'
2503 or 'not installed on target' for each non-pending location of tracepoint.
2505 * New configure options
2507 --enable-libmcheck/--disable-libmcheck
2508 By default, development versions are built with -lmcheck on hosts
2509 that support it, in order to help track memory corruption issues.
2510 Release versions, on the other hand, are built without -lmcheck
2511 by default. The --enable-libmcheck/--disable-libmcheck configure
2512 options allow the user to override that default.
2513 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2514 This configure option allows the user to build GDB with
2515 libbabeltrace using which GDB can read Common Trace Format data.
2517 * New commands (for set/show, see "New options" below)
2520 Catch signals. This is similar to "handle", but allows commands and
2521 conditions to be attached.
2524 List the BFDs known to GDB.
2526 python-interactive [command]
2528 Start a Python interactive prompt, or evaluate the optional command
2529 and print the result of expressions.
2532 "py" is a new alias for "python".
2534 enable type-printer [name]...
2535 disable type-printer [name]...
2536 Enable or disable type printers.
2540 ** For the Renesas Super-H architecture, the "regs" command has been removed
2541 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2546 set print type methods (on|off)
2547 show print type methods
2548 Control whether method declarations are displayed by "ptype".
2549 The default is to show them.
2551 set print type typedefs (on|off)
2552 show print type typedefs
2553 Control whether typedef definitions are displayed by "ptype".
2554 The default is to show them.
2556 set filename-display basename|relative|absolute
2557 show filename-display
2558 Control the way in which filenames is displayed.
2559 The default is "relative", which preserves previous behavior.
2561 set trace-buffer-size
2562 show trace-buffer-size
2563 Request target to change the size of trace buffer.
2565 set remote trace-buffer-size-packet auto|on|off
2566 show remote trace-buffer-size-packet
2567 Control the use of the remote protocol `QTBuffer:size' packet.
2571 Control display of debugging messages related to ARM AArch64.
2574 set debug coff-pe-read
2575 show debug coff-pe-read
2576 Control display of debugging messages related to reading of COFF/PE
2581 Control display of debugging messages related to Mach-O symbols
2584 set debug notification
2585 show debug notification
2586 Control display of debugging info for async remote notification.
2590 ** Command parameter changes are now notified using new async record
2591 "=cmd-param-changed".
2592 ** Trace frame changes caused by command "tfind" are now notified using
2593 new async record "=traceframe-changed".
2594 ** The creation, deletion and modification of trace state variables
2595 are now notified using new async records "=tsv-created",
2596 "=tsv-deleted" and "=tsv-modified".
2597 ** The start and stop of process record are now notified using new
2598 async record "=record-started" and "=record-stopped".
2599 ** Memory changes are now notified using new async record
2601 ** The data-disassemble command response will include a "fullname" field
2602 containing the absolute file name when source has been requested.
2603 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2604 command, to allow pattern filling of memory areas.
2605 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2606 library load/unload events.
2607 ** The response to breakpoint commands and breakpoint async records
2608 includes an "installed" field containing a boolean state about each
2609 non-pending tracepoint location is whether installed on target or not.
2610 ** Output of the "-trace-status" command includes a "trace-file" field
2611 containing the name of the trace file being examined. This field is
2612 optional, and only present when examining a trace file.
2613 ** The "fullname" field is now always present along with the "file" field,
2614 even if the file cannot be found by GDB.
2616 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2617 You must have the LZMA library available when configuring GDB for this
2618 feature to be enabled. For more information, see:
2619 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2621 * New remote packets
2624 Set the size of trace buffer. The remote stub reports support for this
2625 packet to gdb's qSupported query.
2628 Enable Branch Trace Store (BTS)-based branch tracing for the current
2629 thread. The remote stub reports support for this packet to gdb's
2633 Disable branch tracing for the current thread. The remote stub reports
2634 support for this packet to gdb's qSupported query.
2637 Read the traced branches for the current thread. The remote stub
2638 reports support for this packet to gdb's qSupported query.
2640 *** Changes in GDB 7.5
2642 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2643 for more x32 ABI info.
2645 * GDB now supports access to MIPS DSP registers on Linux targets.
2647 * GDB now supports debugging microMIPS binaries.
2649 * The "info os" command on GNU/Linux can now display information on
2650 several new classes of objects managed by the operating system:
2651 "info os procgroups" lists process groups
2652 "info os files" lists file descriptors
2653 "info os sockets" lists internet-domain sockets
2654 "info os shm" lists shared-memory regions
2655 "info os semaphores" lists semaphores
2656 "info os msg" lists message queues
2657 "info os modules" lists loaded kernel modules
2659 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2660 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2661 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2662 options and inspect the probe arguments using the new $_probe_arg family
2663 of convenience variables. You can obtain more information about SystemTap
2664 in <http://sourceware.org/systemtap/>.
2666 * GDB now supports reversible debugging on ARM, it allows you to
2667 debug basic ARM and THUMB instructions, and provides
2668 record/replay support.
2670 * The option "symbol-reloading" has been deleted as it is no longer used.
2674 ** GDB commands implemented in Python can now be put in command class
2677 ** The "maint set python print-stack on|off" is now deleted.
2679 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2680 apply "flag enum"-style pretty-printing to any enum.
2682 ** gdb.lookup_symbol can now work when there is no current frame.
2684 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2685 the source at which the symbol was defined.
2687 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2688 method 'value'. The former indicates whether the symbol needs a
2689 frame in order to compute its value, and the latter computes the
2692 ** A new method 'referenced_value' on gdb.Value objects which can
2693 dereference pointer as well as C++ reference values.
2695 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2696 which return the global and static blocks (as gdb.Block objects),
2697 of the underlying symbol table, respectively.
2699 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2700 object associated with a PC value.
2702 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2703 of the address range occupied by code for the current source line.
2705 * Go language support.
2706 GDB now supports debugging programs written in the Go programming
2709 * GDBserver now supports stdio connections.
2710 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2712 * The binary "gdbtui" can no longer be built or installed.
2713 Use "gdb -tui" instead.
2715 * GDB will now print "flag" enums specially. A flag enum is one where
2716 all the enumerator values have no bits in common when pairwise
2717 "and"ed. When printing a value whose type is a flag enum, GDB will
2718 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2719 (gdb) print (enum E) 3
2722 * The filename part of a linespec will now match trailing components
2723 of a source file name. For example, "break gcc/expr.c:1000" will
2724 now set a breakpoint in build/gcc/expr.c, but not
2725 build/libcpp/expr.c.
2727 * The "info proc" and "generate-core-file" commands will now also
2728 work on remote targets connected to GDBserver on Linux.
2730 * The command "info catch" has been removed. It has been disabled
2731 since December 2007.
2733 * The "catch exception" and "catch assert" commands now accept
2734 a condition at the end of the command, much like the "break"
2735 command does. For instance:
2737 (gdb) catch exception Constraint_Error if Barrier = True
2739 Previously, it was possible to add a condition to such catchpoints,
2740 but it had to be done as a second step, after the catchpoint had been
2741 created, using the "condition" command.
2743 * The "info static-tracepoint-marker" command will now also work on
2744 native Linux targets with in-process agent.
2746 * GDB can now set breakpoints on inlined functions.
2748 * The .gdb_index section has been updated to include symbols for
2749 inlined functions. GDB will ignore older .gdb_index sections by
2750 default, which could cause symbol files to be loaded more slowly
2751 until their .gdb_index sections can be recreated. The new command
2752 "set use-deprecated-index-sections on" will cause GDB to use any older
2753 .gdb_index sections it finds. This will restore performance, but the
2754 ability to set breakpoints on inlined functions will be lost in symbol
2755 files with older .gdb_index sections.
2757 The .gdb_index section has also been updated to record more information
2758 about each symbol. This speeds up the "info variables", "info functions"
2759 and "info types" commands when used with programs having the .gdb_index
2760 section, as well as speeding up debugging with shared libraries using
2761 the .gdb_index section.
2763 * Ada support for GDB/MI Variable Objects has been added.
2765 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2770 ** New command -info-os is the MI equivalent of "info os".
2772 ** Output logs ("set logging" and related) now include MI output.
2776 ** "set use-deprecated-index-sections on|off"
2777 "show use-deprecated-index-sections on|off"
2778 Controls the use of deprecated .gdb_index sections.
2780 ** "catch load" and "catch unload" can be used to stop when a shared
2781 library is loaded or unloaded, respectively.
2783 ** "enable count" can be used to auto-disable a breakpoint after
2786 ** "info vtbl" can be used to show the virtual method tables for
2787 C++ and Java objects.
2789 ** "explore" and its sub commands "explore value" and "explore type"
2790 can be used to recursively explore values and types of
2791 expressions. These commands are available only if GDB is
2792 configured with '--with-python'.
2794 ** "info auto-load" shows status of all kinds of auto-loaded files,
2795 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2796 sequences of commands files, "info auto-load python-scripts"
2797 shows status of auto-loading Python script files,
2798 "info auto-load local-gdbinit" shows status of loading init file
2799 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2800 status of inferior specific thread debugging shared library loading.
2802 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2803 and "show auto-load-scripts" commands have been deprecated, use their
2804 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2805 and "show auto-load python-scripts" counterparts instead.
2807 ** "dprintf location,format,args..." creates a dynamic printf, which
2808 is basically a breakpoint that does a printf and immediately
2809 resumes your program's execution, so it is like a printf that you
2810 can insert dynamically at runtime instead of at compiletime.
2812 ** "set print symbol"
2814 Controls whether GDB attempts to display the symbol, if any,
2815 corresponding to addresses it prints. This defaults to "on", but
2816 you can set it to "off" to restore GDB's previous behavior.
2818 * Deprecated commands
2820 ** For the Renesas Super-H architecture, the "regs" command has been
2821 deprecated, and "info all-registers" should be used instead.
2825 Renesas RL78 rl78-*-elf
2826 HP OpenVMS ia64 ia64-hp-openvms*
2828 * GDBserver supports evaluation of breakpoint conditions. When
2829 support is advertised by GDBserver, GDB may be told to send the
2830 breakpoint conditions in bytecode form to GDBserver. GDBserver
2831 will only report the breakpoint trigger to GDB when its condition
2836 set mips compression
2837 show mips compression
2838 Select the compressed ISA encoding used in functions that have no symbol
2839 information available. The encoding can be set to either of:
2842 and is updated automatically from ELF file flags if available.
2844 set breakpoint condition-evaluation
2845 show breakpoint condition-evaluation
2846 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2847 GDBserver ("target"). Default option "auto" chooses the most efficient
2849 This option can improve debugger efficiency depending on the speed of the
2853 Disable auto-loading globally.
2856 Show auto-loading setting of all kinds of auto-loaded files.
2858 set auto-load gdb-scripts on|off
2859 show auto-load gdb-scripts
2860 Control auto-loading of GDB canned sequences of commands files.
2862 set auto-load python-scripts on|off
2863 show auto-load python-scripts
2864 Control auto-loading of Python script files.
2866 set auto-load local-gdbinit on|off
2867 show auto-load local-gdbinit
2868 Control loading of init file (.gdbinit) from current directory.
2870 set auto-load libthread-db on|off
2871 show auto-load libthread-db
2872 Control auto-loading of inferior specific thread debugging shared library.
2874 set auto-load scripts-directory <dir1>[:<dir2>...]
2875 show auto-load scripts-directory
2876 Set a list of directories from which to load auto-loaded scripts.
2877 Automatically loaded Python scripts and GDB scripts are located in one
2878 of the directories listed by this option.
2879 The delimiter (':' above) may differ according to the host platform.
2881 set auto-load safe-path <dir1>[:<dir2>...]
2882 show auto-load safe-path
2883 Set a list of directories from which it is safe to auto-load files.
2884 The delimiter (':' above) may differ according to the host platform.
2886 set debug auto-load on|off
2887 show debug auto-load
2888 Control display of debugging info for auto-loading the files above.
2890 set dprintf-style gdb|call|agent
2892 Control the way in which a dynamic printf is performed; "gdb"
2893 requests a GDB printf command, while "call" causes dprintf to call a
2894 function in the inferior. "agent" requests that the target agent
2895 (such as GDBserver) do the printing.
2897 set dprintf-function <expr>
2898 show dprintf-function
2899 set dprintf-channel <expr>
2900 show dprintf-channel
2901 Set the function and optional first argument to the call when using
2902 the "call" style of dynamic printf.
2904 set disconnected-dprintf on|off
2905 show disconnected-dprintf
2906 Control whether agent-style dynamic printfs continue to be in effect
2907 after GDB disconnects.
2909 * New configure options
2911 --with-auto-load-dir
2912 Configure default value for the 'set auto-load scripts-directory'
2913 setting above. It defaults to '$debugdir:$datadir/auto-load',
2914 $debugdir representing global debugging info directories (available
2915 via 'show debug-file-directory') and $datadir representing GDB's data
2916 directory (available via 'show data-directory').
2918 --with-auto-load-safe-path
2919 Configure default value for the 'set auto-load safe-path' setting
2920 above. It defaults to the --with-auto-load-dir setting.
2922 --without-auto-load-safe-path
2923 Set 'set auto-load safe-path' to '/', effectively disabling this
2926 * New remote packets
2928 z0/z1 conditional breakpoints extension
2930 The z0/z1 breakpoint insertion packets have been extended to carry
2931 a list of conditional expressions over to the remote stub depending on the
2932 condition evaluation mode. The use of this extension can be controlled
2933 via the "set remote conditional-breakpoints-packet" command.
2937 Specify the signals which the remote stub may pass to the debugged
2938 program without GDB involvement.
2940 * New command line options
2942 --init-command=FILE, -ix Like --command, -x but execute it
2943 before loading inferior.
2944 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2945 execute it before loading inferior.
2947 *** Changes in GDB 7.4
2949 * GDB now handles ambiguous linespecs more consistently; the existing
2950 FILE:LINE support has been expanded to other types of linespecs. A
2951 breakpoint will now be set on all matching locations in all
2952 inferiors, and locations will be added or removed according to
2955 * GDB now allows you to skip uninteresting functions and files when
2956 stepping with the "skip function" and "skip file" commands.
2958 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2959 and "show remote hardware-watchpoint-length-limit". These allows to
2960 set or show the maximum length limit (in bytes) of a remote
2961 target hardware watchpoint.
2963 This allows e.g. to use "unlimited" hardware watchpoints with the
2964 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2965 watchpoints are slower than real hardware watchpoints but are
2966 significantly faster than gdb software watchpoints.
2970 ** The register_pretty_printer function in module gdb.printing now takes
2971 an optional `replace' argument. If True, the new printer replaces any
2974 ** The "maint set python print-stack on|off" command has been
2975 deprecated and will be deleted in GDB 7.5.
2976 A new command: "set python print-stack none|full|message" has
2977 replaced it. Additionally, the default for "print-stack" is
2978 now "message", which just prints the error message without
2981 ** A prompt substitution hook (prompt_hook) is now available to the
2984 ** A new Python module, gdb.prompt has been added to the GDB Python
2985 modules library. This module provides functionality for
2986 escape sequences in prompts (used by set/show
2987 extended-prompt). These escape sequences are replaced by their
2988 corresponding value.
2990 ** Python commands and convenience-functions located in
2991 'data-directory'/python/gdb/command and
2992 'data-directory'/python/gdb/function are now automatically loaded
2995 ** Blocks now provide four new attributes. global_block and
2996 static_block will return the global and static blocks
2997 respectively. is_static and is_global are boolean attributes
2998 that indicate if the block is one of those two types.
3000 ** Symbols now provide the "type" attribute, the type of the symbol.
3002 ** The "gdb.breakpoint" function has been deprecated in favor of
3005 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3006 of a function. This class is based on the "finish" command
3007 available in the CLI.
3009 ** Type objects for struct and union types now allow access to
3010 the fields using standard Python dictionary (mapping) methods.
3011 For example, "some_type['myfield']" now works, as does
3012 "some_type.items()".
3014 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3017 ** A new function, "deep_items" has been added to the gdb.types
3018 module in the GDB Python modules library. This function returns
3019 an iterator over the fields of a struct or union type. Unlike
3020 the standard Python "iteritems" method, it will recursively traverse
3021 any anonymous fields.
3025 ** "*stopped" events can report several new "reason"s, such as
3028 ** Breakpoint changes are now notified using new async records, like
3029 "=breakpoint-modified".
3031 ** New command -ada-task-info.
3033 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3034 $sdir specifies the default system locations of shared libraries.
3035 $pdir specifies the directory where the libpthread used by the application
3038 GDB no longer looks in $sdir and $pdir after it has searched the directories
3039 mentioned in libthread-db-search-path. If you want to search those
3040 directories, they must be specified in libthread-db-search-path.
3041 The default value of libthread-db-search-path on GNU/Linux and Solaris
3042 systems is now "$sdir:$pdir".
3044 $pdir is not supported by gdbserver, it is currently ignored.
3045 $sdir is supported by gdbserver.
3047 * New configure option --with-iconv-bin.
3048 When using the internationalization support like the one in the GNU C
3049 library, GDB will invoke the "iconv" program to get a list of supported
3050 character sets. If this program lives in a non-standard location, one can
3051 use this option to specify where to find it.
3053 * When natively debugging programs on PowerPC BookE processors running
3054 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3055 watchpoints, which specify a mask in addition to an address to watch.
3056 The mask specifies that some bits of an address (the bits which are
3057 reset in the mask) should be ignored when matching the address accessed
3058 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3059 section in the user manual for more details.
3061 * The new option --once causes GDBserver to stop listening for connections once
3062 the first connection is made. The listening port used by GDBserver will
3063 become available after that.
3065 * New commands "info macros" and "alias" have been added.
3067 * New function parameters suffix @entry specifies value of function parameter
3068 at the time the function got called. Entry values are available only since
3074 "!" is now an alias of the "shell" command.
3075 Note that no space is needed between "!" and SHELL COMMAND.
3079 watch EXPRESSION mask MASK_VALUE
3080 The watch command now supports the mask argument which allows creation
3081 of masked watchpoints, if the current architecture supports this feature.
3083 info auto-load-scripts [REGEXP]
3084 This command was formerly named "maintenance print section-scripts".
3085 It is now generally useful and is no longer a maintenance-only command.
3087 info macro [-all] [--] MACRO
3088 The info macro command has new options `-all' and `--'. The first for
3089 printing all definitions of a macro. The second for explicitly specifying
3090 the end of arguments and the beginning of the macro name in case the macro
3091 name starts with a hyphen.
3093 collect[/s] EXPRESSIONS
3094 The tracepoint collect command now takes an optional modifier "/s"
3095 that directs it to dereference pointer-to-character types and
3096 collect the bytes of memory up to a zero byte. The behavior is
3097 similar to what you see when you use the regular print command on a
3098 string. An optional integer following the "/s" sets a bound on the
3099 number of bytes that will be collected.
3102 The trace start command now interprets any supplied arguments as a
3103 note to be recorded with the trace run, with an effect similar to
3104 setting the variable trace-notes.
3107 The trace stop command now interprets any arguments as a note to be
3108 mentioned along with the tstatus report that the trace was stopped
3109 with a command. The effect is similar to setting the variable
3112 * Tracepoints can now be enabled and disabled at any time after a trace
3113 experiment has been started using the standard "enable" and "disable"
3114 commands. It is now possible to start a trace experiment with no enabled
3115 tracepoints; GDB will display a warning, but will allow the experiment to
3116 begin, assuming that tracepoints will be enabled as needed while the trace
3119 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3120 locations with 4-byte instructions, when they were previously
3121 limited to locations with instructions of 5 bytes or longer.
3125 set debug dwarf2-read
3126 show debug dwarf2-read
3127 Turns on or off display of debugging messages related to reading
3128 DWARF debug info. The default is off.
3130 set debug symtab-create
3131 show debug symtab-create
3132 Turns on or off display of debugging messages related to symbol table
3133 creation. The default is off.
3136 show extended-prompt
3137 Set the GDB prompt, and allow escape sequences to be inserted to
3138 display miscellaneous information (see 'help set extended-prompt'
3139 for the list of sequences). This prompt (and any information
3140 accessed through the escape sequences) is updated every time the
3141 prompt is displayed.
3143 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3144 show print entry-values
3145 Set printing of frame argument values at function entry. In some cases
3146 GDB can determine the value of function argument which was passed by the
3147 function caller, even if the value was modified inside the called function.
3149 set debug entry-values
3150 show debug entry-values
3151 Control display of debugging info for determining frame argument values at
3152 function entry and virtual tail call frames.
3154 set basenames-may-differ
3155 show basenames-may-differ
3156 Set whether a source file may have multiple base names.
3157 (A "base name" is the name of a file with the directory part removed.
3158 Example: The base name of "/home/user/hello.c" is "hello.c".)
3159 If set, GDB will canonicalize file names (e.g., expand symlinks)
3160 before comparing them. Canonicalization is an expensive operation,
3161 but it allows the same file be known by more than one base name.
3162 If not set (the default), all source files are assumed to have just
3163 one base name, and gdb will do file name comparisons more efficiently.
3169 Set a user name and notes for the current and any future trace runs.
3170 This is useful for long-running and/or disconnected traces, to
3171 inform others (or yourself) as to who is running the trace, supply
3172 contact information, or otherwise explain what is going on.
3174 set trace-stop-notes
3175 show trace-stop-notes
3176 Set a note attached to the trace run, that is displayed when the
3177 trace has been stopped by a tstop command. This is useful for
3178 instance as an explanation, if you are stopping a trace run that was
3179 started by someone else.
3181 * New remote packets
3185 Dynamically enable a tracepoint in a started trace experiment.
3189 Dynamically disable a tracepoint in a started trace experiment.
3193 Set the user and notes of the trace run.
3197 Query the current status of a tracepoint.
3201 Query the minimum length of instruction at which a fast tracepoint may
3204 * Dcache size (number of lines) and line-size are now runtime-configurable
3205 via "set dcache line" and "set dcache line-size" commands.
3209 Texas Instruments TMS320C6x tic6x-*-*
3213 Renesas RL78 rl78-*-elf
3215 *** Changes in GDB 7.3.1
3217 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3219 *** Changes in GDB 7.3
3221 * GDB has a new command: "thread find [REGEXP]".
3222 It finds the thread id whose name, target id, or thread extra info
3223 matches the given regular expression.
3225 * The "catch syscall" command now works on mips*-linux* targets.
3227 * The -data-disassemble MI command now supports modes 2 and 3 for
3228 dumping the instruction opcodes.
3230 * New command line options
3232 -data-directory DIR Specify DIR as the "data-directory".
3233 This is mostly for testing purposes.
3235 * The "maint set python auto-load on|off" command has been renamed to
3236 "set auto-load-scripts on|off".
3238 * GDB has a new command: "set directories".
3239 It is like the "dir" command except that it replaces the
3240 source path list instead of augmenting it.
3242 * GDB now understands thread names.
3244 On GNU/Linux, "info threads" will display the thread name as set by
3245 prctl or pthread_setname_np.
3247 There is also a new command, "thread name", which can be used to
3248 assign a name internally for GDB to display.
3251 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3252 has been integrated into GDB.
3256 ** The function gdb.Write now accepts an optional keyword 'stream'.
3257 This keyword, when provided, will direct the output to either
3258 stdout, stderr, or GDB's logging output.
3260 ** Parameters can now be be sub-classed in Python, and in particular
3261 you may implement the get_set_doc and get_show_doc functions.
3262 This improves how Parameter set/show documentation is processed
3263 and allows for more dynamic content.
3265 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3266 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3267 have an is_valid method.
3269 ** Breakpoints can now be sub-classed in Python, and in particular
3270 you may implement a 'stop' function that is executed each time
3271 the inferior reaches that breakpoint.
3273 ** New function gdb.lookup_global_symbol looks up a global symbol.
3275 ** GDB values in Python are now callable if the value represents a
3276 function. For example, if 'some_value' represents a function that
3277 takes two integer parameters and returns a value, you can call
3278 that function like so:
3280 result = some_value (10,20)
3282 ** Module gdb.types has been added.
3283 It contains a collection of utilities for working with gdb.Types objects:
3284 get_basic_type, has_field, make_enum_dict.
3286 ** Module gdb.printing has been added.
3287 It contains utilities for writing and registering pretty-printers.
3288 New classes: PrettyPrinter, SubPrettyPrinter,
3289 RegexpCollectionPrettyPrinter.
3290 New function: register_pretty_printer.
3292 ** New commands "info pretty-printers", "enable pretty-printer" and
3293 "disable pretty-printer" have been added.
3295 ** gdb.parameter("directories") is now available.
3297 ** New function gdb.newest_frame returns the newest frame in the
3300 ** The gdb.InferiorThread class has a new "name" attribute. This
3301 holds the thread's name.
3303 ** Python Support for Inferior events.
3304 Python scripts can add observers to be notified of events
3305 occurring in the process being debugged.
3306 The following events are currently supported:
3307 - gdb.events.cont Continue event.
3308 - gdb.events.exited Inferior exited event.
3309 - gdb.events.stop Signal received, and Breakpoint hit events.
3313 ** GDB now puts template parameters in scope when debugging in an
3314 instantiation. For example, if you have:
3316 template<int X> int func (void) { return X; }
3318 then if you step into func<5>, "print X" will show "5". This
3319 feature requires proper debuginfo support from the compiler; it
3320 was added to GCC 4.5.
3322 ** The motion commands "next", "finish", "until", and "advance" now
3323 work better when exceptions are thrown. In particular, GDB will
3324 no longer lose control of the inferior; instead, the GDB will
3325 stop the inferior at the point at which the exception is caught.
3326 This functionality requires a change in the exception handling
3327 code that was introduced in GCC 4.5.
3329 * GDB now follows GCC's rules on accessing volatile objects when
3330 reading or writing target state during expression evaluation.
3331 One notable difference to prior behavior is that "print x = 0"
3332 no longer generates a read of x; the value of the assignment is
3333 now always taken directly from the value being assigned.
3335 * GDB now has some support for using labels in the program's source in
3336 linespecs. For instance, you can use "advance label" to continue
3337 execution to a label.
3339 * GDB now has support for reading and writing a new .gdb_index
3340 section. This section holds a fast index of DWARF debugging
3341 information and can be used to greatly speed up GDB startup and
3342 operation. See the documentation for `save gdb-index' for details.
3344 * The "watch" command now accepts an optional "-location" argument.
3345 When used, this causes GDB to watch the memory referred to by the
3346 expression. Such a watchpoint is never deleted due to it going out
3349 * GDB now supports thread debugging of core dumps on GNU/Linux.
3351 GDB now activates thread debugging using the libthread_db library
3352 when debugging GNU/Linux core dumps, similarly to when debugging
3353 live processes. As a result, when debugging a core dump file, GDB
3354 is now able to display pthread_t ids of threads. For example, "info
3355 threads" shows the same output as when debugging the process when it
3356 was live. In earlier releases, you'd see something like this:
3359 * 1 LWP 6780 main () at main.c:10
3361 While now you see this:
3364 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3366 It is also now possible to inspect TLS variables when debugging core
3369 When debugging a core dump generated on a machine other than the one
3370 used to run GDB, you may need to point GDB at the correct
3371 libthread_db library with the "set libthread-db-search-path"
3372 command. See the user manual for more details on this command.
3374 * When natively debugging programs on PowerPC BookE processors running
3375 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3376 which stop execution of the inferior whenever it executes an instruction
3377 at any address within the specified range. See the "PowerPC Embedded"
3378 section in the user manual for more details.
3380 * New features in the GDB remote stub, GDBserver
3382 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3383 and i686 LynxOS (version 5.x).
3385 ** GDBserver is now supported on Blackfin Linux.
3387 * New native configurations
3389 ia64 HP-UX ia64-*-hpux*
3393 Analog Devices, Inc. Blackfin Processor bfin-*
3395 * Ada task switching is now supported on sparc-elf targets when
3396 debugging a program using the Ravenscar Profile. For more information,
3397 see the "Tasking Support when using the Ravenscar Profile" section
3398 in the GDB user manual.
3400 * Guile support was removed.
3402 * New features in the GNU simulator
3404 ** The --map-info flag lists all known core mappings.
3406 ** CFI flashes may be simulated via the "cfi" device.
3408 *** Changes in GDB 7.2
3410 * Shared library support for remote targets by default
3412 When GDB is configured for a generic, non-OS specific target, like
3413 for example, --target=arm-eabi or one of the many *-*-elf targets,
3414 GDB now queries remote stubs for loaded shared libraries using the
3415 `qXfer:libraries:read' packet. Previously, shared library support
3416 was always disabled for such configurations.
3420 ** Argument Dependent Lookup (ADL)
3422 In C++ ADL lookup directs function search to the namespaces of its
3423 arguments even if the namespace has not been imported.
3433 Here the compiler will search for `foo' in the namespace of 'b'
3434 and find A::foo. GDB now supports this. This construct is commonly
3435 used in the Standard Template Library for operators.
3437 ** Improved User Defined Operator Support
3439 In addition to member operators, GDB now supports lookup of operators
3440 defined in a namespace and imported with a `using' directive, operators
3441 defined in the global scope, operators imported implicitly from an
3442 anonymous namespace, and the ADL operators mentioned in the previous
3444 GDB now also supports proper overload resolution for all the previously
3445 mentioned flavors of operators.
3447 ** static const class members
3449 Printing of static const class members that are initialized in the
3450 class definition has been fixed.
3452 * Windows Thread Information Block access.
3454 On Windows targets, GDB now supports displaying the Windows Thread
3455 Information Block (TIB) structure. This structure is visible either
3456 by using the new command `info w32 thread-information-block' or, by
3457 dereferencing the new convenience variable named `$_tlb', a
3458 thread-specific pointer to the TIB. This feature is also supported
3459 when remote debugging using GDBserver.
3461 * Static tracepoints
3463 Static tracepoints are calls in the user program into a tracing
3464 library. One such library is a port of the LTTng kernel tracer to
3465 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3466 When debugging with GDBserver, GDB now supports combining the GDB
3467 tracepoint machinery with such libraries. For example: the user can
3468 use GDB to probe a static tracepoint marker (a call from the user
3469 program into the tracing library) with the new "strace" command (see
3470 "New commands" below). This creates a "static tracepoint" in the
3471 breakpoint list, that can be manipulated with the same feature set
3472 as fast and regular tracepoints. E.g., collect registers, local and
3473 global variables, collect trace state variables, and define
3474 tracepoint conditions. In addition, the user can collect extra
3475 static tracepoint marker specific data, by collecting the new
3476 $_sdata internal variable. When analyzing the trace buffer, you can
3477 inspect $_sdata like any other variable available to GDB. For more
3478 information, see the "Tracepoints" chapter in GDB user manual. New
3479 remote packets have been defined to support static tracepoints, see
3480 the "New remote packets" section below.
3482 * Better reconstruction of tracepoints after disconnected tracing
3484 GDB will attempt to download the original source form of tracepoint
3485 definitions when starting a trace run, and then will upload these
3486 upon reconnection to the target, resulting in a more accurate
3487 reconstruction of the tracepoints that are in use on the target.
3491 You can now exercise direct control over the ways that GDB can
3492 affect your program. For instance, you can disallow the setting of
3493 breakpoints, so that the program can run continuously (assuming
3494 non-stop mode). In addition, the "observer" variable is available
3495 to switch all of the different controls; in observer mode, GDB
3496 cannot affect the target's behavior at all, which is useful for
3497 tasks like diagnosing live systems in the field.
3499 * The new convenience variable $_thread holds the number of the
3502 * New remote packets
3506 Return the address of the Windows Thread Information Block of a given thread.
3510 In response to several of the tracepoint packets, the target may now
3511 also respond with a number of intermediate `qRelocInsn' request
3512 packets before the final result packet, to have GDB handle
3513 relocating an instruction to execute at a different address. This
3514 is particularly useful for stubs that support fast tracepoints. GDB
3515 reports support for this feature in the qSupported packet.
3519 List static tracepoint markers in the target program.
3523 List static tracepoint markers at a given address in the target
3526 qXfer:statictrace:read
3528 Read the static trace data collected (by a `collect $_sdata'
3529 tracepoint action). The remote stub reports support for this packet
3530 to gdb's qSupported query.
3534 Send the current settings of GDB's permission flags.
3538 Send part of the source (textual) form of a tracepoint definition,
3539 which includes location, conditional, and action list.
3541 * The source command now accepts a -s option to force searching for the
3542 script in the source search path even if the script name specifies
3545 * New features in the GDB remote stub, GDBserver
3547 - GDBserver now support tracepoints (including fast tracepoints, and
3548 static tracepoints). The feature is currently supported by the
3549 i386-linux and amd64-linux builds. See the "Tracepoints support
3550 in gdbserver" section in the manual for more information.
3552 GDBserver JIT compiles the tracepoint's conditional agent
3553 expression bytecode into native code whenever possible for low
3554 overhead dynamic tracepoints conditionals. For such tracepoints,
3555 an expression that examines program state is evaluated when the
3556 tracepoint is reached, in order to determine whether to capture
3557 trace data. If the condition is simple and false, processing the
3558 tracepoint finishes very quickly and no data is gathered.
3560 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3561 for static tracepoints support.
3563 - GDBserver now supports x86_64 Windows 64-bit debugging.
3565 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3566 it understands register description.
3568 * The --batch flag now disables pagination and queries.
3570 * X86 general purpose registers
3572 GDB now supports reading/writing byte, word and double-word x86
3573 general purpose registers directly. This means you can use, say,
3574 $ah or $ax to refer, respectively, to the byte register AH and
3575 16-bit word register AX that are actually portions of the 32-bit
3576 register EAX or 64-bit register RAX.
3578 * The `commands' command now accepts a range of breakpoints to modify.
3579 A plain `commands' following a command that creates multiple
3580 breakpoints affects all the breakpoints set by that command. This
3581 applies to breakpoints set by `rbreak', and also applies when a
3582 single `break' command creates multiple breakpoints (e.g.,
3583 breakpoints on overloaded c++ functions).
3585 * The `rbreak' command now accepts a filename specification as part of
3586 its argument, limiting the functions selected by the regex to those
3587 in the specified file.
3589 * Support for remote debugging Windows and SymbianOS shared libraries
3590 from Unix hosts has been improved. Non Windows GDB builds now can
3591 understand target reported file names that follow MS-DOS based file
3592 system semantics, such as file names that include drive letters and
3593 use the backslash character as directory separator. This makes it
3594 possible to transparently use the "set sysroot" and "set
3595 solib-search-path" on Unix hosts to point as host copies of the
3596 target's shared libraries. See the new command "set
3597 target-file-system-kind" described below, and the "Commands to
3598 specify files" section in the user manual for more information.
3602 eval template, expressions...
3603 Convert the values of one or more expressions under the control
3604 of the string template to a command line, and call it.
3606 set target-file-system-kind unix|dos-based|auto
3607 show target-file-system-kind
3608 Set or show the assumed file system kind for target reported file
3611 save breakpoints <filename>
3612 Save all current breakpoint definitions to a file suitable for use
3613 in a later debugging session. To read the saved breakpoint
3614 definitions, use the `source' command.
3616 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3619 info static-tracepoint-markers
3620 Display information about static tracepoint markers in the target.
3622 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3623 Define a static tracepoint by probing a marker at the given
3624 function, line, address, or marker ID.
3628 Enable and disable observer mode.
3630 set may-write-registers on|off
3631 set may-write-memory on|off
3632 set may-insert-breakpoints on|off
3633 set may-insert-tracepoints on|off
3634 set may-insert-fast-tracepoints on|off
3635 set may-interrupt on|off
3636 Set individual permissions for GDB effects on the target. Note that
3637 some of these settings can have undesirable or surprising
3638 consequences, particularly when changed in the middle of a session.
3639 For instance, disabling the writing of memory can prevent
3640 breakpoints from being inserted, cause single-stepping to fail, or
3641 even crash your program, if you disable after breakpoints have been
3642 inserted. However, GDB should not crash.
3644 set record memory-query on|off
3645 show record memory-query
3646 Control whether to stop the inferior if memory changes caused
3647 by an instruction cannot be recorded.
3652 The disassemble command now supports "start,+length" form of two arguments.
3656 ** GDB now provides a new directory location, called the python directory,
3657 where Python scripts written for GDB can be installed. The location
3658 of that directory is <data-directory>/python, where <data-directory>
3659 is the GDB data directory. For more details, see section `Scripting
3660 GDB using Python' in the manual.
3662 ** The GDB Python API now has access to breakpoints, symbols, symbol
3663 tables, program spaces, inferiors, threads and frame's code blocks.
3664 Additionally, GDB Parameters can now be created from the API, and
3665 manipulated via set/show in the CLI.
3667 ** New functions gdb.target_charset, gdb.target_wide_charset,
3668 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3670 ** New exception gdb.GdbError.
3672 ** Pretty-printers are now also looked up in the current program space.
3674 ** Pretty-printers can now be individually enabled and disabled.
3676 ** GDB now looks for names of Python scripts to auto-load in a
3677 special section named `.debug_gdb_scripts', in addition to looking
3678 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3680 * Tracepoint actions were unified with breakpoint commands. In particular,
3681 there are no longer differences in "info break" output for breakpoints and
3682 tracepoints and the "commands" command can be used for both tracepoints and
3683 regular breakpoints.
3687 ARM Symbian arm*-*-symbianelf*
3689 * D language support.
3690 GDB now supports debugging programs written in the D programming
3693 * GDB now supports the extended ptrace interface for PowerPC which is
3694 available since Linux kernel version 2.6.34. This automatically enables
3695 any hardware breakpoints and additional hardware watchpoints available in
3696 the processor. The old ptrace interface exposes just one hardware
3697 watchpoint and no hardware breakpoints.
3699 * GDB is now able to use the Data Value Compare (DVC) register available on
3700 embedded PowerPC processors to implement in hardware simple watchpoint
3701 conditions of the form:
3703 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3705 This works in native GDB running on Linux kernels with the extended ptrace
3706 interface mentioned above.
3708 *** Changes in GDB 7.1
3712 ** Namespace Support
3714 GDB now supports importing of namespaces in C++. This enables the
3715 user to inspect variables from imported namespaces. Support for
3716 namepace aliasing has also been added. So, if a namespace is
3717 aliased in the current scope (e.g. namepace C=A; ) the user can
3718 print variables using the alias (e.g. (gdb) print C::x).
3722 All known bugs relating to the printing of virtual base class were
3723 fixed. It is now possible to call overloaded static methods using a
3728 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3729 and reinterpret_cast<> are now handled by the C++ expression parser.
3733 Xilinx MicroBlaze microblaze-*-*
3738 Xilinx MicroBlaze microblaze
3741 * Multi-program debugging.
3743 GDB now has support for multi-program (a.k.a. multi-executable or
3744 multi-exec) debugging. This allows for debugging multiple inferiors
3745 simultaneously each running a different program under the same GDB
3746 session. See "Debugging Multiple Inferiors and Programs" in the
3747 manual for more information. This implied some user visible changes
3748 in the multi-inferior support. For example, "info inferiors" now
3749 lists inferiors that are not running yet or that have exited
3750 already. See also "New commands" and "New options" below.
3752 * New tracing features
3754 GDB's tracepoint facility now includes several new features:
3756 ** Trace state variables
3758 GDB tracepoints now include support for trace state variables, which
3759 are variables managed by the target agent during a tracing
3760 experiment. They are useful for tracepoints that trigger each
3761 other, so for instance one tracepoint can count hits in a variable,
3762 and then a second tracepoint has a condition that is true when the
3763 count reaches a particular value. Trace state variables share the
3764 $-syntax of GDB convenience variables, and can appear in both
3765 tracepoint actions and condition expressions. Use the "tvariable"
3766 command to create, and "info tvariables" to view; see "Trace State
3767 Variables" in the manual for more detail.
3771 GDB now includes an option for defining fast tracepoints, which
3772 targets may implement more efficiently, such as by installing a jump
3773 into the target agent rather than a trap instruction. The resulting
3774 speedup can be by two orders of magnitude or more, although the
3775 tradeoff is that some program locations on some target architectures
3776 might not allow fast tracepoint installation, for instance if the
3777 instruction to be replaced is shorter than the jump. To request a
3778 fast tracepoint, use the "ftrace" command, with syntax identical to
3779 the regular trace command.
3781 ** Disconnected tracing
3783 It is now possible to detach GDB from the target while it is running
3784 a trace experiment, then reconnect later to see how the experiment
3785 is going. In addition, a new variable disconnected-tracing lets you
3786 tell the target agent whether to continue running a trace if the
3787 connection is lost unexpectedly.
3791 GDB now has the ability to save the trace buffer into a file, and
3792 then use that file as a target, similarly to you can do with
3793 corefiles. You can select trace frames, print data that was
3794 collected in them, and use tstatus to display the state of the
3795 tracing run at the moment that it was saved. To create a trace
3796 file, use "tsave <filename>", and to use it, do "target tfile
3799 ** Circular trace buffer
3801 You can ask the target agent to handle the trace buffer as a
3802 circular buffer, discarding the oldest trace frames to make room for
3803 newer ones, by setting circular-trace-buffer to on. This feature may
3804 not be available for all target agents.
3809 The disassemble command, when invoked with two arguments, now requires
3810 the arguments to be comma-separated.
3813 The info variables command now displays variable definitions. Files
3814 which only declare a variable are not shown.
3817 The source command is now capable of sourcing Python scripts.
3818 This feature is dependent on the debugger being build with Python
3821 Related to this enhancement is also the introduction of a new command
3822 "set script-extension" (see below).
3824 * New commands (for set/show, see "New options" below)
3826 record save [<FILENAME>]
3827 Save a file (in core file format) containing the process record
3828 execution log for replay debugging at a later time.
3830 record restore <FILENAME>
3831 Restore the process record execution log that was saved at an
3832 earlier time, for replay debugging.
3834 add-inferior [-copies <N>] [-exec <FILENAME>]
3837 clone-inferior [-copies <N>] [ID]
3838 Make a new inferior ready to execute the same program another
3839 inferior has loaded.
3844 maint info program-spaces
3845 List the program spaces loaded into GDB.
3847 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3848 show remote interrupt-sequence
3849 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3850 as the sequence to the remote target in order to interrupt the execution.
3851 Ctrl-C is a default. Some system prefers BREAK which is high level of
3852 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3853 Magic SysRq g. It is BREAK signal and character 'g'.
3855 set remote interrupt-on-connect [on | off]
3856 show remote interrupt-on-connect
3857 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3858 remote target when gdb connects to it. This is needed when you debug
3861 set remotebreak [on | off]
3863 Deprecated. Use "set/show remote interrupt-sequence" instead.
3865 tvariable $NAME [ = EXP ]
3866 Create or modify a trace state variable.
3869 List trace state variables and their values.
3871 delete tvariable $NAME ...
3872 Delete one or more trace state variables.
3875 Evaluate the given expressions without collecting anything into the
3876 trace buffer. (Valid in tracepoint actions only.)
3878 ftrace FN / FILE:LINE / *ADDR
3879 Define a fast tracepoint at the given function, line, or address.
3881 * New expression syntax
3883 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3884 GDB now parses 0b101010 identically with 42.
3888 set follow-exec-mode new|same
3889 show follow-exec-mode
3890 Control whether GDB reuses the same inferior across an exec call or
3891 creates a new one. This is useful to be able to restart the old
3892 executable after the inferior having done an exec call.
3894 set default-collect EXPR, ...
3895 show default-collect
3896 Define a list of expressions to be collected at each tracepoint.
3897 This is a useful way to ensure essential items are not overlooked,
3898 such as registers or a critical global variable.
3900 set disconnected-tracing
3901 show disconnected-tracing
3902 If set to 1, the target is instructed to continue tracing if it
3903 loses its connection to GDB. If 0, the target is to stop tracing
3906 set circular-trace-buffer
3907 show circular-trace-buffer
3908 If set to on, the target is instructed to use a circular trace buffer
3909 and discard the oldest trace frames instead of stopping the trace due
3910 to a full trace buffer. If set to off, the trace stops when the buffer
3911 fills up. Some targets may not support this.
3913 set script-extension off|soft|strict
3914 show script-extension
3915 If set to "off", the debugger does not perform any script language
3916 recognition, and all sourced files are assumed to be GDB scripts.
3917 If set to "soft" (the default), files are sourced according to
3918 filename extension, falling back to GDB scripts if the first
3920 If set to "strict", files are sourced according to filename extension.
3922 set ada trust-PAD-over-XVS on|off
3923 show ada trust-PAD-over-XVS
3924 If off, activate a workaround against a bug in the debugging information
3925 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3926 the GCC sources for more information about the GNAT encoding and
3927 PAD types in particular). It is always safe to set this option to
3928 off, but this introduces a slight performance penalty. The default
3931 * Python API Improvements
3933 ** GDB provides the new class gdb.LazyString. This is useful in
3934 some pretty-printing cases. The new method gdb.Value.lazy_string
3935 provides a simple way to create objects of this type.
3937 ** The fields returned by gdb.Type.fields now have an
3938 `is_base_class' attribute.
3940 ** The new method gdb.Type.range returns the range of an array type.
3942 ** The new method gdb.parse_and_eval can be used to parse and
3943 evaluate an expression.
3945 * New remote packets
3948 Define a trace state variable.
3951 Get the current value of a trace state variable.
3954 Set desired tracing behavior upon disconnection.
3957 Set the trace buffer to be linear or circular.
3960 Get data about the tracepoints currently in use.
3964 Process record now works correctly with hardware watchpoints.
3966 Multiple bug fixes have been made to the mips-irix port, making it
3967 much more reliable. In particular:
3968 - Debugging threaded applications is now possible again. Previously,
3969 GDB would hang while starting the program, or while waiting for
3970 the program to stop at a breakpoint.
3971 - Attaching to a running process no longer hangs.
3972 - An error occurring while loading a core file has been fixed.
3973 - Changing the value of the PC register now works again. This fixes
3974 problems observed when using the "jump" command, or when calling
3975 a function from GDB, or even when assigning a new value to $pc.
3976 - With the "finish" and "return" commands, the return value for functions
3977 returning a small array is now correctly printed.
3978 - It is now possible to break on shared library code which gets executed
3979 during a shared library init phase (code executed while executing
3980 their .init section). Previously, the breakpoint would have no effect.
3981 - GDB is now able to backtrace through the signal handler for
3982 non-threaded programs.
3984 PIE (Position Independent Executable) programs debugging is now supported.
3985 This includes debugging execution of PIC (Position Independent Code) shared
3986 libraries although for that, it should be possible to run such libraries as an
3989 *** Changes in GDB 7.0
3991 * GDB now has an interface for JIT compilation. Applications that
3992 dynamically generate code can create symbol files in memory and register
3993 them with GDB. For users, the feature should work transparently, and
3994 for JIT developers, the interface is documented in the GDB manual in the
3995 "JIT Compilation Interface" chapter.
3997 * Tracepoints may now be conditional. The syntax is as for
3998 breakpoints; either an "if" clause appended to the "trace" command,
3999 or the "condition" command is available. GDB sends the condition to
4000 the target for evaluation using the same bytecode format as is used
4001 for tracepoint actions.
4003 * The disassemble command now supports: an optional /r modifier, print the
4004 raw instructions in hex as well as in symbolic form, and an optional /m
4005 modifier to print mixed source+assembly.
4007 * Process record and replay
4009 In a architecture environment that supports ``process record and
4010 replay'', ``process record and replay'' target can record a log of
4011 the process execution, and replay it with both forward and reverse
4014 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4015 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4016 set execution-direction {forward|reverse}, for targets that support
4019 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4020 feature is available with a native GDB running on kernel version
4023 * GDB now has support for multi-byte and wide character sets on the
4024 target. Strings whose character type is wchar_t, char16_t, or
4025 char32_t are now correctly printed. GDB supports wide- and unicode-
4026 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4027 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4028 `printf'. This feature requires iconv to work properly; if your
4029 system does not have a working iconv, GDB can use GNU libiconv. See
4030 the installation instructions for more information.
4032 * GDB now supports automatic retrieval of shared library files from
4033 remote targets. To use this feature, specify a system root that begins
4034 with the `remote:' prefix, either via the `set sysroot' command or via
4035 the `--with-sysroot' configure-time option.
4037 * "info sharedlibrary" now takes an optional regex of libraries to show,
4038 and it now reports if a shared library has no debugging information.
4040 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4041 now complete on file names.
4043 * When completing in expressions, gdb will attempt to limit
4044 completions to allowable structure or union fields, where appropriate.
4045 For instance, consider:
4047 # struct example { int f1; double f2; };
4048 # struct example variable;
4051 If the user types TAB at the end of this command line, the available
4052 completions will be "f1" and "f2".
4054 * Inlined functions are now supported. They show up in backtraces, and
4055 the "step", "next", and "finish" commands handle them automatically.
4057 * GDB now supports the token-splicing (##) and stringification (#)
4058 operators when expanding macros. It also supports variable-arity
4061 * GDB now supports inspecting extra signal information, exported by
4062 the new $_siginfo convenience variable. The feature is currently
4063 implemented on linux ARM, i386 and amd64.
4065 * GDB can now display the VFP floating point registers and NEON vector
4066 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4067 can provide these registers (requires Linux 2.6.30 or later). Remote
4068 and simulator targets may also provide them.
4070 * New remote packets
4073 Search memory for a sequence of bytes.
4076 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4077 operation over reliable transport links. Use of this packet is
4078 controlled by the `set remote noack-packet' command.
4081 Kill the process with the specified process ID. Use this in preference
4082 to `k' when multiprocess protocol extensions are supported.
4085 Obtains additional operating system information
4089 Read or write additional signal information.
4091 * Removed remote protocol undocumented extension
4093 An undocumented extension to the remote protocol's `S' stop reply
4094 packet that permited the stub to pass a process id was removed.
4095 Remote servers should use the `T' stop reply packet instead.
4097 * GDB now supports multiple function calling conventions according to the
4098 DWARF-2 DW_AT_calling_convention function attribute.
4100 * The SH target utilizes the aforementioned change to distinguish between gcc
4101 and Renesas calling convention. It also adds the new CLI commands
4102 `set/show sh calling-convention'.
4104 * GDB can now read compressed debug sections, as produced by GNU gold
4105 with the --compress-debug-sections=zlib flag.
4107 * 64-bit core files are now supported on AIX.
4109 * Thread switching is now supported on Tru64.
4111 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4112 which will be allocated using malloc later in program execution.
4114 * The qXfer:libraries:read remote procotol packet now allows passing a
4115 list of section offsets.
4117 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4118 conditions handling signals delivered during attach or thread creation
4119 have also been fixed.
4121 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4122 From the user's standpoint, all unqualified instances of True and False
4123 are treated as the standard definitions, regardless of context.
4125 * GDB now parses C++ symbol and type names more flexibly. For
4128 template<typename T> class C { };
4131 GDB will now correctly handle all of:
4133 ptype C<char const *>
4134 ptype C<char const*>
4135 ptype C<const char *>
4136 ptype C<const char*>
4138 * New features in the GDB remote stub, gdbserver
4140 - The "--wrapper" command-line argument tells gdbserver to use a
4141 wrapper program to launch programs for debugging.
4143 - On PowerPC and S/390 targets, it is now possible to use a single
4144 gdbserver executable to debug both 32-bit and 64-bit programs.
4145 (This requires gdbserver itself to be built as a 64-bit executable.)
4147 - gdbserver uses the new noack protocol mode for TCP connections to
4148 reduce communications latency, if also supported and enabled in GDB.
4150 - Support for the sparc64-linux-gnu target is now included in
4153 - The amd64-linux build of gdbserver now supports debugging both
4154 32-bit and 64-bit programs.
4156 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4157 now support hardware watchpoints, and will use them automatically
4162 GDB now has support for scripting using Python. Whether this is
4163 available is determined at configure time.
4165 New GDB commands can now be written in Python.
4167 * Ada tasking support
4169 Ada tasks can now be inspected in GDB. The following commands have
4173 Print the list of Ada tasks.
4175 Print detailed information about task number N.
4177 Print the task number of the current task.
4179 Switch the context of debugging to task number N.
4181 * Support for user-defined prefixed commands. The "define" command can
4182 add new commands to existing prefixes, e.g. "target".
4184 * Multi-inferior, multi-process debugging.
4186 GDB now has generalized support for multi-inferior debugging. See
4187 "Debugging Multiple Inferiors" in the manual for more information.
4188 Although availability still depends on target support, the command
4189 set is more uniform now. The GNU/Linux specific multi-forks support
4190 has been migrated to this new framework. This implied some user
4191 visible changes; see "New commands" and also "Removed commands"
4194 * Target descriptions can now describe the target OS ABI. See the
4195 "Target Description Format" section in the user manual for more
4198 * Target descriptions can now describe "compatible" architectures
4199 to indicate that the target can execute applications for a different
4200 architecture in addition to those for the main target architecture.
4201 See the "Target Description Format" section in the user manual for
4204 * Multi-architecture debugging.
4206 GDB now includes general supports for debugging applications on
4207 hybrid systems that use more than one single processor architecture
4208 at the same time. Each such hybrid architecture still requires
4209 specific support to be added. The only hybrid architecture supported
4210 in this version of GDB is the Cell Broadband Engine.
4212 * GDB now supports integrated debugging of Cell/B.E. applications that
4213 use both the PPU and SPU architectures. To enable support for hybrid
4214 Cell/B.E. debugging, you need to configure GDB to support both the
4215 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4216 --enable-targets configure option.
4218 * Non-stop mode debugging.
4220 For some targets, GDB now supports an optional mode of operation in
4221 which you can examine stopped threads while other threads continue
4222 to execute freely. This is referred to as non-stop mode, with the
4223 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4224 section in the user manual for more information.
4226 To be able to support remote non-stop debugging, a remote stub needs
4227 to implement the non-stop mode remote protocol extensions, as
4228 described in the "Remote Non-Stop" section of the user manual. The
4229 GDB remote stub, gdbserver, has been adjusted to support these
4230 extensions on linux targets.
4232 * New commands (for set/show, see "New options" below)
4234 catch syscall [NAME(S) | NUMBER(S)]
4235 Catch system calls. Arguments, which should be names of system
4236 calls or their numbers, mean catch only those syscalls. Without
4237 arguments, every syscall will be caught. When the inferior issues
4238 any of the specified syscalls, GDB will stop and announce the system
4239 call, both when it is called and when its call returns. This
4240 feature is currently available with a native GDB running on the
4241 Linux Kernel, under the following architectures: x86, x86_64,
4242 PowerPC and PowerPC64.
4244 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4246 Search memory for a sequence of bytes.
4248 maint set python print-stack
4249 maint show python print-stack
4250 Show a stack trace when an error is encountered in a Python script.
4253 Invoke CODE by passing it to the Python interpreter.
4258 These allow macros to be defined, undefined, and listed
4262 Show operating system information about processes.
4265 List the inferiors currently under GDB's control.
4268 Switch focus to inferior number NUM.
4271 Detach from inferior number NUM.
4274 Kill inferior number NUM.
4278 set spu stop-on-load
4279 show spu stop-on-load
4280 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4282 set spu auto-flush-cache
4283 show spu auto-flush-cache
4284 Control whether to automatically flush the software-managed cache
4285 during Cell/B.E. debugging.
4287 set sh calling-convention
4288 show sh calling-convention
4289 Control the calling convention used when calling SH target functions.
4292 show debug timestamp
4293 Control display of timestamps with GDB debugging output.
4295 set disassemble-next-line
4296 show disassemble-next-line
4297 Control display of disassembled source lines or instructions when
4300 set remote noack-packet
4301 show remote noack-packet
4302 Set/show the use of remote protocol QStartNoAckMode packet. See above
4303 under "New remote packets."
4305 set remote query-attached-packet
4306 show remote query-attached-packet
4307 Control use of remote protocol `qAttached' (query-attached) packet.
4309 set remote read-siginfo-object
4310 show remote read-siginfo-object
4311 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4314 set remote write-siginfo-object
4315 show remote write-siginfo-object
4316 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4319 set remote reverse-continue
4320 show remote reverse-continue
4321 Control use of remote protocol 'bc' (reverse-continue) packet.
4323 set remote reverse-step
4324 show remote reverse-step
4325 Control use of remote protocol 'bs' (reverse-step) packet.
4327 set displaced-stepping
4328 show displaced-stepping
4329 Control displaced stepping mode. Displaced stepping is a way to
4330 single-step over breakpoints without removing them from the debuggee.
4331 Also known as "out-of-line single-stepping".
4334 show debug displaced
4335 Control display of debugging info for displaced stepping.
4337 maint set internal-error
4338 maint show internal-error
4339 Control what GDB does when an internal error is detected.
4341 maint set internal-warning
4342 maint show internal-warning
4343 Control what GDB does when an internal warning is detected.
4348 Use a wrapper program to launch programs for debugging.
4350 set multiple-symbols (all|ask|cancel)
4351 show multiple-symbols
4352 The value of this variable can be changed to adjust the debugger behavior
4353 when an expression or a breakpoint location contains an ambiguous symbol
4354 name (an overloaded function name, for instance).
4356 set breakpoint always-inserted
4357 show breakpoint always-inserted
4358 Keep breakpoints always inserted in the target, as opposed to inserting
4359 them when resuming the target, and removing them when the target stops.
4360 This option can improve debugger performance on slow remote targets.
4362 set arm fallback-mode (arm|thumb|auto)
4363 show arm fallback-mode
4364 set arm force-mode (arm|thumb|auto)
4366 These commands control how ARM GDB determines whether instructions
4367 are ARM or Thumb. The default for both settings is auto, which uses
4368 the current CPSR value for instructions without symbols; previous
4369 versions of GDB behaved as if "set arm fallback-mode arm".
4371 set disable-randomization
4372 show disable-randomization
4373 Standalone programs run with the virtual address space randomization enabled
4374 by default on some platforms. This option keeps the addresses stable across
4375 multiple debugging sessions.
4379 Control whether other threads are stopped or not when some thread hits
4384 Requests that asynchronous execution is enabled in the target, if available.
4385 In this case, it's possible to resume target in the background, and interact
4386 with GDB while the target is running. "show target-async" displays the
4387 current state of asynchronous execution of the target.
4389 set target-wide-charset
4390 show target-wide-charset
4391 The target-wide-charset is the name of the character set that GDB
4392 uses when printing characters whose type is wchar_t.
4394 set tcp auto-retry (on|off)
4396 set tcp connect-timeout
4397 show tcp connect-timeout
4398 These commands allow GDB to retry failed TCP connections to a remote stub
4399 with a specified timeout period; this is useful if the stub is launched
4400 in parallel with GDB but may not be ready to accept connections immediately.
4402 set libthread-db-search-path
4403 show libthread-db-search-path
4404 Control list of directories which GDB will search for appropriate
4407 set schedule-multiple (on|off)
4408 show schedule-multiple
4409 Allow GDB to resume all threads of all processes or only threads of
4410 the current process.
4414 Use more aggressive caching for accesses to the stack. This improves
4415 performance of remote debugging (particularly backtraces) without
4416 affecting correctness.
4418 set interactive-mode (on|off|auto)
4419 show interactive-mode
4420 Control whether GDB runs in interactive mode (on) or not (off).
4421 When in interactive mode, GDB waits for the user to answer all
4422 queries. Otherwise, GDB does not wait and assumes the default
4423 answer. When set to auto (the default), GDB determines which
4424 mode to use based on the stdin settings.
4429 For program forks, this is replaced by the new more generic `info
4430 inferiors' command. To list checkpoints, you can still use the
4431 `info checkpoints' command, which was an alias for the `info forks'
4435 Replaced by the new `inferior' command. To switch between
4436 checkpoints, you can still use the `restart' command, which was an
4437 alias for the `fork' command.
4440 This is removed, since some targets don't have a notion of
4441 processes. To switch between processes, you can still use the
4442 `inferior' command using GDB's own inferior number.
4445 For program forks, this is replaced by the new more generic `kill
4446 inferior' command. To delete a checkpoint, you can still use the
4447 `delete checkpoint' command, which was an alias for the `delete
4451 For program forks, this is replaced by the new more generic `detach
4452 inferior' command. To detach a checkpoint, you can still use the
4453 `detach checkpoint' command, which was an alias for the `detach
4456 * New native configurations
4458 x86/x86_64 Darwin i[34567]86-*-darwin*
4460 x86_64 MinGW x86_64-*-mingw*
4464 Lattice Mico32 lm32-*
4465 x86 DICOS i[34567]86-*-dicos*
4466 x86_64 DICOS x86_64-*-dicos*
4469 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4470 (mingw32ce) debugging.
4476 These commands were actually not implemented on any target.
4478 *** Changes in GDB 6.8
4480 * New native configurations
4482 NetBSD/hppa hppa*-*netbsd*
4483 Xtensa GNU/Linux xtensa*-*-linux*
4487 NetBSD/hppa hppa*-*-netbsd*
4488 Xtensa GNU/Lunux xtensa*-*-linux*
4490 * Change in command line behavior -- corefiles vs. process ids.
4492 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4493 attaching to process NUMBER fails, GDB no longer attempts to open a
4494 core file named NUMBER. Attaching to a program using the -c option
4495 is no longer supported. Instead, use the '-p' or '--pid' options.
4497 * GDB can now be built as a native debugger for debugging Windows x86
4498 (mingw32) Portable Executable (PE) programs.
4500 * Pending breakpoints no longer change their number when their address
4503 * GDB now supports breakpoints with multiple locations,
4504 including breakpoints on C++ constructors, inside C++ templates,
4505 and in inlined functions.
4507 * GDB's ability to debug optimized code has been improved. GDB more
4508 accurately identifies function bodies and lexical blocks that occupy
4509 more than one contiguous range of addresses.
4511 * Target descriptions can now describe registers for PowerPC.
4513 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4514 registers on PowerPC targets.
4516 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4517 targets even when the libthread_db library is not available.
4519 * The GDB remote stub, gdbserver, now supports the new file transfer
4520 commands (remote put, remote get, and remote delete).
4522 * The GDB remote stub, gdbserver, now supports run and attach in
4523 extended-remote mode.
4525 * hppa*64*-*-hpux11* target broken
4526 The debugger is unable to start a program and fails with the following
4527 error: "Error trying to get information about dynamic linker".
4528 The gdb-6.7 release is also affected.
4530 * GDB now supports the --enable-targets= configure option to allow
4531 building a single GDB executable that supports multiple remote
4532 target architectures.
4534 * GDB now supports debugging C and C++ programs which use the
4535 Decimal Floating Point extension. In addition, the PowerPC target
4536 now has a set of pseudo-registers to inspect decimal float values
4537 stored in two consecutive float registers.
4539 * The -break-insert MI command can optionally create pending
4542 * Improved support for debugging Ada
4543 Many improvements to the Ada language support have been made. These
4545 - Better support for Ada2005 interface types
4546 - Improved handling of arrays and slices in general
4547 - Better support for Taft-amendment types
4548 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4550 - Improved command completion in Ada
4553 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4558 set print frame-arguments (all|scalars|none)
4559 show print frame-arguments
4560 The value of this variable can be changed to control which argument
4561 values should be printed by the debugger when displaying a frame.
4566 Transfer files to and from a remote target, and delete remote files.
4573 Transfer files to and from a remote target, and delete remote files.
4575 * New remote packets
4582 Open, close, read, write, and delete files on the remote system.
4585 Attach to an existing process on the remote system, in extended-remote
4589 Run a new process on the remote system, in extended-remote mode.
4591 *** Changes in GDB 6.7
4593 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4594 bfd, libiberty and opcodes, as revealed by static analysis donated by
4595 Coverity, Inc. (http://scan.coverity.com).
4597 * When looking up multiply-defined global symbols, GDB will now prefer the
4598 symbol definition in the current shared library if it was built using the
4599 -Bsymbolic linker option.
4601 * When the Text User Interface (TUI) is not configured, GDB will now
4602 recognize the -tui command-line option and print a message that the TUI
4605 * The GDB remote stub, gdbserver, now has lower overhead for high
4606 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4608 * GDB for MIPS targets now autodetects whether a remote target provides
4609 32-bit or 64-bit register values.
4611 * Support for C++ member pointers has been improved.
4613 * GDB now understands XML target descriptions, which specify the
4614 target's overall architecture. GDB can read a description from
4615 a local file or over the remote serial protocol.
4617 * Vectors of single-byte data use a new integer type which is not
4618 automatically displayed as character or string data.
4620 * The /s format now works with the print command. It displays
4621 arrays of single-byte integers and pointers to single-byte integers
4624 * Target descriptions can now describe target-specific registers,
4625 for architectures which have implemented the support (currently
4626 only ARM, M68K, and MIPS).
4628 * GDB and the GDB remote stub, gdbserver, now support the XScale
4631 * The GDB remote stub, gdbserver, has been updated to support
4632 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4633 has been rewritten to use the standard GDB remote protocol.
4635 * GDB can now step into C++ functions which are called through thunks.
4637 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4639 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4640 layout. It also supports a TextSeg= and DataSeg= response when only
4641 segment base addresses (rather than offsets) are available.
4643 * The /i format now outputs any trailing branch delay slot instructions
4644 immediately following the last instruction within the count specified.
4646 * The GDB remote protocol "T" stop reply packet now supports a
4647 "library" response. Combined with the new "qXfer:libraries:read"
4648 packet, this response allows GDB to debug shared libraries on targets
4649 where the operating system manages the list of loaded libraries (e.g.
4650 Windows and SymbianOS).
4652 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4653 (DLLs) on Windows and Windows CE targets.
4655 * GDB now supports a faster verification that a .debug file matches its binary
4656 according to its build-id signature, if the signature is present.
4662 Enable or disable hardware flow control (RTS/CTS) on the serial port
4663 when debugging using remote targets.
4665 set mem inaccessible-by-default
4666 show mem inaccessible-by-default
4667 If the target supplies a memory map, for instance via the remote
4668 protocol's "qXfer:memory-map:read" packet, setting this variable
4669 prevents GDB from accessing memory outside the memory map. This
4670 is useful for targets with memory mapped registers or which react
4671 badly to accesses of unmapped address space.
4673 set breakpoint auto-hw
4674 show breakpoint auto-hw
4675 If the target supplies a memory map, for instance via the remote
4676 protocol's "qXfer:memory-map:read" packet, setting this variable
4677 lets GDB use hardware breakpoints automatically for memory regions
4678 where it can not use software breakpoints. This covers both the
4679 "break" command and internal breakpoints used for other commands
4680 including "next" and "finish".
4683 catch exception unhandled
4684 Stop the program execution when Ada exceptions are raised.
4687 Stop the program execution when an Ada assertion failed.
4691 Set an alternate system root for target files. This is a more
4692 general version of "set solib-absolute-prefix", which is now
4693 an alias to "set sysroot".
4696 Provide extended SPU facility status information. This set of
4697 commands is available only when debugging the Cell/B.E. SPU
4700 * New native configurations
4702 OpenBSD/sh sh*-*openbsd*
4705 unset tdesc filename
4707 Use the specified local file as an XML target description, and do
4708 not query the target for its built-in description.
4712 OpenBSD/sh sh*-*-openbsd*
4713 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4714 Toshiba Media Processor mep-elf
4716 * New remote packets
4719 Ignore the specified signals; pass them directly to the debugged program
4720 without stopping other threads or reporting them to GDB.
4722 qXfer:features:read:
4723 Read an XML target description from the target, which describes its
4728 Read or write contents of an spufs file on the target system. These
4729 packets are available only on the Cell/B.E. SPU architecture.
4731 qXfer:libraries:read:
4732 Report the loaded shared libraries. Combined with new "T" packet
4733 response, this packet allows GDB to debug shared libraries on
4734 targets where the operating system manages the list of loaded
4735 libraries (e.g. Windows and SymbianOS).
4739 Support for these obsolete configurations has been removed.
4747 i[34567]86-*-lynxos*
4748 i[34567]86-*-netware*
4749 i[34567]86-*-sco3.2v5*
4750 i[34567]86-*-sco3.2v4*
4752 i[34567]86-*-sysv4.2*
4755 i[34567]86-*-unixware2*
4756 i[34567]86-*-unixware*
4765 * Other removed features
4772 Various m68k-only ROM monitors.
4779 Various Renesas ROM monitors and debugging interfaces for SH and
4784 Support for a Macraigor serial interface to on-chip debugging.
4785 GDB does not directly support the newer parallel or USB
4790 A debug information format. The predecessor to DWARF 2 and
4791 DWARF 3, which are still supported.
4793 Support for the HP aCC compiler on HP-UX/PA-RISC
4795 SOM-encapsulated symbolic debugging information, automatic
4796 invocation of pxdb, and the aCC custom C++ ABI. This does not
4797 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4798 with aCC can still be debugged on an assembly level.
4800 MIPS ".pdr" sections
4802 A MIPS-specific format used to describe stack frame layout
4803 in debugging information.
4807 GDB could work with an older version of Guile to debug
4808 the interpreter and Scheme programs running in it.
4810 set mips stack-arg-size
4811 set mips saved-gpreg-size
4813 Use "set mips abi" to control parameter passing for MIPS.
4815 *** Changes in GDB 6.6
4820 Cell Broadband Engine SPU spu-elf
4822 * GDB can now be configured as a cross-debugger targeting native Windows
4823 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4824 running on a Windows system over TCP/IP to debug Windows programs.
4826 * The GDB remote stub, gdbserver, has been updated to support Windows and
4827 Cygwin debugging. Both single-threaded and multi-threaded programs are
4830 * The "set trust-readonly-sections" command works again. This command was
4831 broken in GDB 6.3, 6.4, and 6.5.
4833 * The "load" command now supports writing to flash memory, if the remote
4834 stub provides the required support.
4836 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4837 longer requires symbolic debug information (e.g. DWARF-2).
4842 unset substitute-path
4843 show substitute-path
4844 Manage a list of substitution rules that GDB uses to rewrite the name
4845 of the directories where the sources are located. This can be useful
4846 for instance when the sources were moved to a different location
4847 between compilation and debugging.
4851 Print each CLI command as it is executed. Each command is prefixed with
4852 a number of `+' symbols representing the nesting depth.
4853 The source command now has a `-v' option to enable the same feature.
4857 The ARM Demon monitor support (RDP protocol, "target rdp").
4859 Kernel Object Display, an embedded debugging feature which only worked with
4860 an obsolete version of Cisco IOS.
4862 The 'set download-write-size' and 'show download-write-size' commands.
4864 * New remote packets
4867 Tell a stub about GDB client features, and request remote target features.
4868 The first feature implemented is PacketSize, which allows the target to
4869 specify the size of packets it can handle - to minimize the number of
4870 packets required and improve performance when connected to a remote
4874 Fetch an OS auxilliary vector from the remote stub. This packet is a
4875 more efficient replacement for qPart:auxv:read.
4877 qXfer:memory-map:read:
4878 Fetch a memory map from the remote stub, including information about
4879 RAM, ROM, and flash memory devices.
4884 Erase and program a flash memory device.
4886 * Removed remote packets
4889 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4890 used it, and only gdbserver implemented it.
4892 *** Changes in GDB 6.5
4896 Renesas M32C/M16C m32c-elf
4898 Morpho Technologies ms1 ms1-elf
4902 init-if-undefined Initialize a convenience variable, but
4903 only if it doesn't already have a value.
4905 The following commands are presently only implemented for native GNU/Linux:
4907 checkpoint Save a snapshot of the program state.
4909 restart <n> Return the program state to a
4910 previously saved state.
4912 info checkpoints List currently saved checkpoints.
4914 delete-checkpoint <n> Delete a previously saved checkpoint.
4916 set|show detach-on-fork Tell gdb whether to detach from a newly
4917 forked process, or to keep debugging it.
4919 info forks List forks of the user program that
4920 are available to be debugged.
4922 fork <n> Switch to debugging one of several
4923 forks of the user program that are
4924 available to be debugged.
4926 delete-fork <n> Delete a fork from the list of forks
4927 that are available to be debugged (and
4928 kill the forked process).
4930 detach-fork <n> Delete a fork from the list of forks
4931 that are available to be debugged (and
4932 allow the process to continue).
4936 Morpho Technologies ms2 ms1-elf
4938 * Improved Windows host support
4940 GDB now builds as a cross debugger hosted on i686-mingw32, including
4941 native console support, and remote communications using either
4942 network sockets or serial ports.
4944 * Improved Modula-2 language support
4946 GDB can now print most types in the Modula-2 syntax. This includes:
4947 basic types, set types, record types, enumerated types, range types,
4948 pointer types and ARRAY types. Procedure var parameters are correctly
4949 printed and hexadecimal addresses and character constants are also
4950 written in the Modula-2 syntax. Best results can be obtained by using
4951 GNU Modula-2 together with the -gdwarf-2 command line option.
4955 The ARM rdi-share module.
4957 The Netware NLM debug server.
4959 *** Changes in GDB 6.4
4961 * New native configurations
4963 OpenBSD/arm arm*-*-openbsd*
4964 OpenBSD/mips64 mips64-*-openbsd*
4968 Morpho Technologies ms1 ms1-elf
4970 * New command line options
4972 --batch-silent As for --batch, but totally silent.
4973 --return-child-result The debugger will exist with the same value
4974 the child (debugged) program exited with.
4975 --eval-command COMMAND, -ex COMMAND
4976 Execute a single GDB CLI command. This may be
4977 specified multiple times and in conjunction
4978 with the --command (-x) option.
4980 * Deprecated commands removed
4982 The following commands, that were deprecated in 2000, have been
4986 set|show arm disassembly-flavor set|show arm disassembler
4987 othernames set arm disassembler
4988 set|show remotedebug set|show debug remote
4989 set|show archdebug set|show debug arch
4990 set|show eventdebug set|show debug event
4993 * New BSD user-level threads support
4995 It is now possible to debug programs using the user-level threads
4996 library on OpenBSD and FreeBSD. Currently supported (target)
4999 FreeBSD/amd64 x86_64-*-freebsd*
5000 FreeBSD/i386 i386-*-freebsd*
5001 OpenBSD/i386 i386-*-openbsd*
5003 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5004 are not yet supported.
5006 * New support for Matsushita MN10300 w/sim added
5007 (Work in progress). mn10300-elf.
5009 * REMOVED configurations and files
5011 VxWorks and the XDR protocol *-*-vxworks
5012 Motorola MCORE mcore-*-*
5013 National Semiconductor NS32000 ns32k-*-*
5015 * New "set print array-indexes" command
5017 After turning this setting "on", GDB prints the index of each element
5018 when displaying arrays. The default is "off" to preserve the previous
5021 * VAX floating point support
5023 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5025 * User-defined command support
5027 In addition to using $arg0..$arg9 for argument passing, it is now possible
5028 to use $argc to determine now many arguments have been passed. See the
5029 section on user-defined commands in the user manual for more information.
5031 *** Changes in GDB 6.3:
5033 * New command line option
5035 GDB now accepts -l followed by a number to set the timeout for remote
5038 * GDB works with GCC -feliminate-dwarf2-dups
5040 GDB now supports a more compact representation of DWARF-2 debug
5041 information using DW_FORM_ref_addr references. These are produced
5042 by GCC with the option -feliminate-dwarf2-dups and also by some
5043 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5044 to use -feliminate-dwarf2-dups.
5046 * Internationalization
5048 When supported by the host system, GDB will be built with
5049 internationalization (libintl). The task of marking up the sources is
5050 continued, we're looking forward to our first translation.
5054 Initial support for debugging programs compiled with the GNAT
5055 implementation of the Ada programming language has been integrated
5056 into GDB. In this release, support is limited to expression evaluation.
5058 * New native configurations
5060 GNU/Linux/m32r m32r-*-linux-gnu
5064 GDB's remote protocol now includes support for the 'p' packet. This
5065 packet is used to fetch individual registers from a remote inferior.
5067 * END-OF-LIFE registers[] compatibility module
5069 GDB's internal register infrastructure has been completely rewritten.
5070 The new infrastructure making possible the implementation of key new
5071 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5074 GDB 6.3 will be the last release to include the the registers[]
5075 compatibility module that allowed out-of-date configurations to
5076 continue to work. This change directly impacts the following
5086 powerpc bdm protocol
5088 Unless there is activity to revive these configurations, they will be
5089 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5091 * OBSOLETE configurations and files
5093 Configurations that have been declared obsolete in this release have
5094 been commented out. Unless there is activity to revive these
5095 configurations, the next release of GDB will have their sources
5096 permanently REMOVED.
5105 *** Changes in GDB 6.2.1:
5107 * MIPS `break main; run' gave an heuristic-fence-post warning
5109 When attempting to run even a simple program, a warning about
5110 heuristic-fence-post being hit would be reported. This problem has
5113 * MIPS IRIX 'long double' crashed GDB
5115 When examining a long double variable, GDB would get a segmentation
5116 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5117 IRIX long double values).
5121 A bug in the VAX stack code was causing problems with the "next"
5122 command. This problem has been fixed.
5124 *** Changes in GDB 6.2:
5126 * Fix for ``many threads''
5128 On GNU/Linux systems that use the NPTL threads library, a program
5129 rapidly creating and deleting threads would confuse GDB leading to the
5132 ptrace: No such process.
5133 thread_db_get_info: cannot get thread info: generic error
5135 This problem has been fixed.
5137 * "-async" and "-noasync" options removed.
5139 Support for the broken "-noasync" option has been removed (it caused
5142 * New ``start'' command.
5144 This command runs the program until the begining of the main procedure.
5146 * New BSD Kernel Data Access Library (libkvm) interface
5148 Using ``target kvm'' it is now possible to debug kernel core dumps and
5149 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5150 platforms. Currently supported (native-only) configurations are:
5152 FreeBSD/amd64 x86_64-*-freebsd*
5153 FreeBSD/i386 i?86-*-freebsd*
5154 NetBSD/i386 i?86-*-netbsd*
5155 NetBSD/m68k m68*-*-netbsd*
5156 NetBSD/sparc sparc-*-netbsd*
5157 OpenBSD/amd64 x86_64-*-openbsd*
5158 OpenBSD/i386 i?86-*-openbsd*
5159 OpenBSD/m68k m68*-openbsd*
5160 OpenBSD/sparc sparc-*-openbsd*
5162 * Signal trampoline code overhauled
5164 Many generic problems with GDB's signal handling code have been fixed.
5165 These include: backtraces through non-contiguous stacks; recognition
5166 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5167 call; backtrace through a signal trampoline; step into and out of
5168 signal handlers; and single-stepping in the signal trampoline.
5170 Please note that kernel bugs are a limiting factor here. These
5171 features have been shown to work on an s390 GNU/Linux system that
5172 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5174 * Cygwin support for DWARF 2 added.
5176 * New native configurations
5178 GNU/Linux/hppa hppa*-*-linux*
5179 OpenBSD/hppa hppa*-*-openbsd*
5180 OpenBSD/m68k m68*-*-openbsd*
5181 OpenBSD/m88k m88*-*-openbsd*
5182 OpenBSD/powerpc powerpc-*-openbsd*
5183 NetBSD/vax vax-*-netbsd*
5184 OpenBSD/vax vax-*-openbsd*
5186 * END-OF-LIFE frame compatibility module
5188 GDB's internal frame infrastructure has been completely rewritten.
5189 The new infrastructure making it possible to support key new features
5190 including DWARF 2 Call Frame Information. To aid in the task of
5191 migrating old configurations to this new infrastructure, a
5192 compatibility module, that allowed old configurations to continue to
5193 work, was also included.
5195 GDB 6.2 will be the last release to include this frame compatibility
5196 module. This change directly impacts the following configurations:
5206 Unless there is activity to revive these configurations, they will be
5207 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5209 * REMOVED configurations and files
5211 Sun 3, running SunOS 3 m68*-*-sunos3*
5212 Sun 3, running SunOS 4 m68*-*-sunos4*
5213 Sun 2, running SunOS 3 m68000-*-sunos3*
5214 Sun 2, running SunOS 4 m68000-*-sunos4*
5215 Motorola 680x0 running LynxOS m68*-*-lynxos*
5216 AT&T 3b1/Unix pc m68*-att-*
5217 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5218 decstation mips-dec-* mips-little-*
5219 riscos mips-*-riscos* mips-*-sysv*
5220 sonymips mips-sony-*
5221 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5223 *** Changes in GDB 6.1.1:
5225 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5227 The TUI (Text-mode User Interface) is now built as part of a default
5228 GDB configuration. It is enabled by either selecting the TUI with the
5229 command line option "-i=tui" or by running the separate "gdbtui"
5230 program. For more information on the TUI, see the manual "Debugging
5233 * Pending breakpoint support (also included in GDB 6.1)
5235 Support has been added to allow you to specify breakpoints in shared
5236 libraries that have not yet been loaded. If a breakpoint location
5237 cannot be found, and the "breakpoint pending" option is set to auto,
5238 GDB queries you if you wish to make the breakpoint pending on a future
5239 shared-library load. If and when GDB resolves the breakpoint symbol,
5240 the pending breakpoint is removed as one or more regular breakpoints
5243 Pending breakpoints are very useful for GCJ Java debugging.
5245 * Fixed ISO-C build problems
5247 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5248 non ISO-C code that stopped them being built using a more strict ISO-C
5249 compiler (e.g., IBM's C compiler).
5251 * Fixed build problem on IRIX 5
5253 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5254 wasn't able to compile compile on an IRIX 5 system.
5256 * Added execute permission to gdb/gdbserver/configure
5258 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5259 permission. This bug would cause configure to fail on a number of
5260 systems (Solaris, IRIX). Ref: server/519.
5262 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5264 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5265 has been updated to use constant array sizes.
5267 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5269 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5270 its generated DWARF Call Frame Info. This encoding was causing GDB to
5271 panic, that panic has been fixed. Ref: gdb/1628.
5273 * Fixed a problem when examining parameters in shared library code.
5275 When examining parameters in optimized shared library code generated
5276 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5277 not available''. GDB now correctly displays the variable's value.
5279 *** Changes in GDB 6.1:
5281 * Removed --with-mmalloc
5283 Support for the mmalloc memory manager has been removed, as it
5284 conflicted with the internal gdb byte cache.
5286 * Changes in AMD64 configurations
5288 The AMD64 target now includes the %cs and %ss registers. As a result
5289 the AMD64 remote protocol has changed; this affects the floating-point
5290 and SSE registers. If you rely on those registers for your debugging,
5291 you should upgrade gdbserver on the remote side.
5293 * Revised SPARC target
5295 The SPARC target has been completely revised, incorporating the
5296 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5297 support for LynxOS and SunOS 4 has been dropped. Calling functions
5298 from within GDB on operating systems with a non-executable stack
5299 (Solaris, OpenBSD) now works.
5303 GDB has a new C++ demangler which does a better job on the mangled
5304 names generated by current versions of g++. It also runs faster, so
5305 with this and other changes gdb should now start faster on large C++
5308 * DWARF 2 Location Expressions
5310 GDB support for location expressions has been extended to support function
5311 arguments and frame bases. Older versions of GDB could crash when they
5314 * C++ nested types and namespaces
5316 GDB's support for nested types and namespaces in C++ has been
5317 improved, especially if you use the DWARF 2 debugging format. (This
5318 is the default for recent versions of GCC on most platforms.)
5319 Specifically, if you have a class "Inner" defined within a class or
5320 namespace "Outer", then GDB realizes that the class's name is
5321 "Outer::Inner", not simply "Inner". This should greatly reduce the
5322 frequency of complaints about not finding RTTI symbols. In addition,
5323 if you are stopped at inside of a function defined within a namespace,
5324 GDB modifies its name lookup accordingly.
5326 * New native configurations
5328 NetBSD/amd64 x86_64-*-netbsd*
5329 OpenBSD/amd64 x86_64-*-openbsd*
5330 OpenBSD/alpha alpha*-*-openbsd*
5331 OpenBSD/sparc sparc-*-openbsd*
5332 OpenBSD/sparc64 sparc64-*-openbsd*
5334 * New debugging protocols
5336 M32R with SDI protocol m32r-*-elf*
5338 * "set prompt-escape-char" command deleted.
5340 The command "set prompt-escape-char" has been deleted. This command,
5341 and its very obscure effet on GDB's prompt, was never documented,
5342 tested, nor mentioned in the NEWS file.
5344 * OBSOLETE configurations and files
5346 Configurations that have been declared obsolete in this release have
5347 been commented out. Unless there is activity to revive these
5348 configurations, the next release of GDB will have their sources
5349 permanently REMOVED.
5351 Sun 3, running SunOS 3 m68*-*-sunos3*
5352 Sun 3, running SunOS 4 m68*-*-sunos4*
5353 Sun 2, running SunOS 3 m68000-*-sunos3*
5354 Sun 2, running SunOS 4 m68000-*-sunos4*
5355 Motorola 680x0 running LynxOS m68*-*-lynxos*
5356 AT&T 3b1/Unix pc m68*-att-*
5357 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5358 decstation mips-dec-* mips-little-*
5359 riscos mips-*-riscos* mips-*-sysv*
5360 sonymips mips-sony-*
5361 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5363 * REMOVED configurations and files
5365 SGI Irix-4.x mips-sgi-irix4 or iris4
5366 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5367 Z8000 simulator z8k-zilog-none or z8ksim
5368 Matsushita MN10200 w/simulator mn10200-*-*
5369 H8/500 simulator h8500-hitachi-hms or h8500hms
5370 HP/PA running BSD hppa*-*-bsd*
5371 HP/PA running OSF/1 hppa*-*-osf*
5372 HP/PA Pro target hppa*-*-pro*
5373 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5374 386BSD i[3456]86-*-bsd*
5375 Sequent family i[3456]86-sequent-sysv4*
5376 i[3456]86-sequent-sysv*
5377 i[3456]86-sequent-bsd*
5378 SPARC running LynxOS sparc-*-lynxos*
5379 SPARC running SunOS 4 sparc-*-sunos4*
5380 Tsqware Sparclet sparclet-*-*
5381 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5383 *** Changes in GDB 6.0:
5387 Support for debugging the Objective-C programming language has been
5388 integrated into GDB.
5390 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5392 DWARF 2's Call Frame Information makes available compiler generated
5393 information that more exactly describes the program's run-time stack.
5394 By using this information, GDB is able to provide more robust stack
5397 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5398 have been updated to use a new backtrace mechanism which includes
5399 DWARF 2 CFI support.
5403 GDB's remote protocol has been extended to include support for hosted
5404 file I/O (where the remote target uses GDB's file system). See GDB's
5405 remote protocol documentation for details.
5407 * All targets using the new architecture framework.
5409 All of GDB's targets have been updated to use the new internal
5410 architecture framework. The way is now open for future GDB releases
5411 to include cross-architecture native debugging support (i386 on amd64,
5414 * GNU/Linux's Thread Local Storage (TLS)
5416 GDB now includes support for for the GNU/Linux implementation of
5417 per-thread variables.
5419 * GNU/Linux's Native POSIX Thread Library (NPTL)
5421 GDB's thread code has been updated to work with either the new
5422 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5424 * Separate debug info.
5426 GDB, in conjunction with BINUTILS, now supports a mechanism for
5427 automatically loading debug information from a separate file. Instead
5428 of shipping full debug and non-debug versions of system libraries,
5429 system integrators can now instead ship just the stripped libraries
5430 and optional debug files.
5432 * DWARF 2 Location Expressions
5434 DWARF 2 Location Expressions allow the compiler to more completely
5435 describe the location of variables (even in optimized code) to the
5438 GDB now includes preliminary support for location expressions (support
5439 for DW_OP_piece is still missing).
5443 A number of long standing bugs that caused GDB to die while starting a
5444 Java application have been fixed. GDB's Java support is now
5445 considered "useable".
5447 * GNU/Linux support for fork, vfork, and exec.
5449 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5450 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5453 * GDB supports logging output to a file
5455 There are two new commands, "set logging" and "show logging", which can be
5456 used to capture GDB's output to a file.
5458 * The meaning of "detach" has changed for gdbserver
5460 The "detach" command will now resume the application, as documented. To
5461 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5464 * d10v, m68hc11 `regs' command deprecated
5466 The `info registers' command has been updated so that it displays the
5467 registers using a format identical to the old `regs' command.
5471 A new command, "maint set profile on/off", has been added. This command can
5472 be used to enable or disable profiling while running GDB, to profile a
5473 session or a set of commands. In addition there is a new configure switch,
5474 "--enable-profiling", which will cause GDB to be compiled with profiling
5475 data, for more informative profiling results.
5477 * Default MI syntax changed to "mi2".
5479 The default MI (machine interface) syntax, enabled by the command line
5480 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5481 "mi1", can be enabled by specifying the option "-i=mi1".
5483 Support for the original "mi0" syntax (included in GDB 5.0) has been
5486 Fix for gdb/192: removed extraneous space when displaying frame level.
5487 Fix for gdb/672: update changelist is now output in mi list format.
5488 Fix for gdb/702: a -var-assign that updates the value now shows up
5489 in a subsequent -var-update.
5491 * New native configurations.
5493 FreeBSD/amd64 x86_64-*-freebsd*
5495 * Multi-arched targets.
5497 HP/PA HPUX11 hppa*-*-hpux*
5498 Renesas M32R/D w/simulator m32r-*-elf*
5500 * OBSOLETE configurations and files
5502 Configurations that have been declared obsolete in this release have
5503 been commented out. Unless there is activity to revive these
5504 configurations, the next release of GDB will have their sources
5505 permanently REMOVED.
5507 Z8000 simulator z8k-zilog-none or z8ksim
5508 Matsushita MN10200 w/simulator mn10200-*-*
5509 H8/500 simulator h8500-hitachi-hms or h8500hms
5510 HP/PA running BSD hppa*-*-bsd*
5511 HP/PA running OSF/1 hppa*-*-osf*
5512 HP/PA Pro target hppa*-*-pro*
5513 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5514 Sequent family i[3456]86-sequent-sysv4*
5515 i[3456]86-sequent-sysv*
5516 i[3456]86-sequent-bsd*
5517 Tsqware Sparclet sparclet-*-*
5518 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5520 * REMOVED configurations and files
5523 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5524 IBM AIX PS/2 i[3456]86-*-aix
5525 i386 running Mach 3.0 i[3456]86-*-mach3*
5526 i386 running Mach i[3456]86-*-mach*
5527 i386 running OSF/1 i[3456]86-*osf1mk*
5528 HP/Apollo 68k Family m68*-apollo*-sysv*,
5530 m68*-hp-bsd*, m68*-hp-hpux*
5531 Argonaut Risc Chip (ARC) arc-*-*
5532 Mitsubishi D30V d30v-*-*
5533 Fujitsu FR30 fr30-*-elf*
5534 OS/9000 i[34]86-*-os9k
5535 I960 with MON960 i960-*-coff
5537 * MIPS $fp behavior changed
5539 The convenience variable $fp, for the MIPS, now consistently returns
5540 the address of the current frame's base. Previously, depending on the
5541 context, $fp could refer to either $sp or the current frame's base
5542 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5543 The GNU Source-Level Debugger''.
5545 *** Changes in GDB 5.3:
5547 * GNU/Linux shared library multi-threaded performance improved.
5549 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5550 `/proc', in preference to `ptrace' for memory reads. This may result
5551 in an improvement in the start-up time of multi-threaded, shared
5552 library applications when run under GDB. One GDB user writes: ``loads
5553 shared libs like mad''.
5555 * ``gdbserver'' now supports multi-threaded applications on some targets
5557 Support for debugging multi-threaded applications which use
5558 the GNU/Linux LinuxThreads package has been added for
5559 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5560 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5562 * GDB now supports C/C++ preprocessor macros.
5564 GDB now expands preprocessor macro invocations in C/C++ expressions,
5565 and provides various commands for showing macro definitions and how
5568 The new command `macro expand EXPRESSION' expands any macro
5569 invocations in expression, and shows the result.
5571 The new command `show macro MACRO-NAME' shows the definition of the
5572 macro named MACRO-NAME, and where it was defined.
5574 Most compilers don't include information about macros in the debugging
5575 information by default. In GCC 3.1, for example, you need to compile
5576 your program with the options `-gdwarf-2 -g3'. If the macro
5577 information is present in the executable, GDB will read it.
5579 * Multi-arched targets.
5581 DEC Alpha (partial) alpha*-*-*
5582 DEC VAX (partial) vax-*-*
5584 National Semiconductor NS32000 (partial) ns32k-*-*
5585 Motorola 68000 (partial) m68k-*-*
5586 Motorola MCORE mcore-*-*
5590 Fujitsu FRV architecture added by Red Hat frv*-*-*
5593 * New native configurations
5595 Alpha NetBSD alpha*-*-netbsd*
5596 SH NetBSD sh*-*-netbsdelf*
5597 MIPS NetBSD mips*-*-netbsd*
5598 UltraSPARC NetBSD sparc64-*-netbsd*
5600 * OBSOLETE configurations and files
5602 Configurations that have been declared obsolete in this release have
5603 been commented out. Unless there is activity to revive these
5604 configurations, the next release of GDB will have their sources
5605 permanently REMOVED.
5607 Mitsubishi D30V d30v-*-*
5608 OS/9000 i[34]86-*-os9k
5609 IBM AIX PS/2 i[3456]86-*-aix
5610 Fujitsu FR30 fr30-*-elf*
5611 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5612 Argonaut Risc Chip (ARC) arc-*-*
5613 i386 running Mach 3.0 i[3456]86-*-mach3*
5614 i386 running Mach i[3456]86-*-mach*
5615 i386 running OSF/1 i[3456]86-*osf1mk*
5616 HP/Apollo 68k Family m68*-apollo*-sysv*,
5618 m68*-hp-bsd*, m68*-hp-hpux*
5619 I960 with MON960 i960-*-coff
5621 * OBSOLETE languages
5623 CHILL, a Pascal like language used by telecommunications companies.
5625 * REMOVED configurations and files
5627 AMD 29k family via UDI a29k-amd-udi, udi29k
5628 A29K VxWorks a29k-*-vxworks
5629 AMD 29000 embedded, using EBMON a29k-none-none
5630 AMD 29000 embedded with COFF a29k-none-coff
5631 AMD 29000 embedded with a.out a29k-none-aout
5633 testsuite/gdb.hp/gdb.threads-hp/ directory
5635 * New command "set max-user-call-depth <nnn>"
5637 This command allows the user to limit the call depth of user-defined
5638 commands. The default is 1024.
5640 * Changes in FreeBSD/i386 native debugging.
5642 Support for the "generate-core-file" has been added.
5644 * New commands "dump", "append", and "restore".
5646 These commands allow data to be copied from target memory
5647 to a bfd-format or binary file (dump and append), and back
5648 from a file into memory (restore).
5650 * Improved "next/step" support on multi-processor Alpha Tru64.
5652 The previous single-step mechanism could cause unpredictable problems,
5653 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5654 of a software single-step mechanism prevents this.
5656 *** Changes in GDB 5.2.1:
5664 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5665 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5666 Fix, by Joel Brobecker imported from mainline.
5668 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5669 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5670 Fix, by Fred Fish, imported from mainline.
5672 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5673 Surprisingly enough, it works now.
5674 By Michal Ludvig, imported from mainline.
5676 i386 hardware watchpoint support:
5677 avoid misses on second run for some targets.
5678 By Pierre Muller, imported from mainline.
5680 *** Changes in GDB 5.2:
5682 * New command "set trust-readonly-sections on[off]".
5684 This command is a hint that tells gdb that read-only sections
5685 really are read-only (ie. that their contents will not change).
5686 In this mode, gdb will go to the object file rather than the
5687 target to read memory from read-only sections (such as ".text").
5688 This can be a significant performance improvement on some
5689 (notably embedded) targets.
5691 * New command "generate-core-file" (or "gcore").
5693 This new gdb command allows the user to drop a core file of the child
5694 process state at any time. So far it's been implemented only for
5695 GNU/Linux and Solaris, but should be relatively easily ported to other
5696 hosts. Argument is core file name (defaults to core.<pid>).
5698 * New command line option
5700 GDB now accepts --pid or -p followed by a process id.
5702 * Change in command line behavior -- corefiles vs. process ids.
5704 There is a subtle behavior in the way in which GDB handles
5705 command line arguments. The first non-flag argument is always
5706 a program to debug, but the second non-flag argument may either
5707 be a corefile or a process id. Previously, GDB would attempt to
5708 open the second argument as a corefile, and if that failed, would
5709 issue a superfluous error message and then attempt to attach it as
5710 a process. Now, if the second argument begins with a non-digit,
5711 it will be treated as a corefile. If it begins with a digit,
5712 GDB will attempt to attach it as a process, and if no such process
5713 is found, will then attempt to open it as a corefile.
5715 * Changes in ARM configurations.
5717 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5718 configuration is fully multi-arch.
5720 * New native configurations
5722 ARM NetBSD arm*-*-netbsd*
5723 x86 OpenBSD i[3456]86-*-openbsd*
5724 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5725 Sparc64 running FreeBSD sparc64-*-freebsd*
5729 Sanyo XStormy16 xstormy16-elf
5731 * OBSOLETE configurations and files
5733 Configurations that have been declared obsolete in this release have
5734 been commented out. Unless there is activity to revive these
5735 configurations, the next release of GDB will have their sources
5736 permanently REMOVED.
5738 AMD 29k family via UDI a29k-amd-udi, udi29k
5739 A29K VxWorks a29k-*-vxworks
5740 AMD 29000 embedded, using EBMON a29k-none-none
5741 AMD 29000 embedded with COFF a29k-none-coff
5742 AMD 29000 embedded with a.out a29k-none-aout
5744 testsuite/gdb.hp/gdb.threads-hp/ directory
5746 * REMOVED configurations and files
5748 TI TMS320C80 tic80-*-*
5750 PowerPC Solaris powerpcle-*-solaris*
5751 PowerPC Windows NT powerpcle-*-cygwin32
5752 PowerPC Netware powerpc-*-netware*
5753 Harris/CXUX m88k m88*-harris-cxux*
5754 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5755 ns32k-utek-sysv* ns32k-utek-*
5756 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5757 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5758 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5759 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5760 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5762 * Changes to command line processing
5764 The new `--args' feature can be used to specify command-line arguments
5765 for the inferior from gdb's command line.
5767 * Changes to key bindings
5769 There is a new `operate-and-get-next' function bound to `C-o'.
5771 *** Changes in GDB 5.1.1
5773 Fix compile problem on DJGPP.
5775 Fix a problem with floating-point registers on the i386 being
5778 Fix to stop GDB crashing on .debug_str debug info.
5780 Numerous documentation fixes.
5782 Numerous testsuite fixes.
5784 *** Changes in GDB 5.1:
5786 * New native configurations
5788 Alpha FreeBSD alpha*-*-freebsd*
5789 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5790 MIPS GNU/Linux mips*-*-linux*
5791 MIPS SGI Irix 6.x mips*-sgi-irix6*
5792 ia64 AIX ia64-*-aix*
5793 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5797 Motorola 68HC11 and 68HC12 m68hc11-elf
5799 UltraSparc running GNU/Linux sparc64-*-linux*
5801 * OBSOLETE configurations and files
5803 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5804 Harris/CXUX m88k m88*-harris-cxux*
5805 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5806 ns32k-utek-sysv* ns32k-utek-*
5807 TI TMS320C80 tic80-*-*
5809 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5810 PowerPC Solaris powerpcle-*-solaris*
5811 PowerPC Windows NT powerpcle-*-cygwin32
5812 PowerPC Netware powerpc-*-netware*
5813 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5814 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5815 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5816 Apple Macintosh (MPW) host N/A
5818 stuff.c (Program to stuff files into a specially prepared space in kdb)
5819 kdb-start.c (Main loop for the standalone kernel debugger)
5821 Configurations that have been declared obsolete in this release have
5822 been commented out. Unless there is activity to revive these
5823 configurations, the next release of GDB will have their sources
5824 permanently REMOVED.
5826 * REMOVED configurations and files
5828 Altos 3068 m68*-altos-*
5829 Convex c1-*-*, c2-*-*
5831 ARM RISCix arm-*-* (as host)
5835 * GDB has been converted to ISO C.
5837 GDB's source code has been converted to ISO C. In particular, the
5838 sources are fully protoized, and rely on standard headers being
5843 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5845 * The MI enabled by default.
5847 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5848 revised and enabled by default. Packages which use GDB as a debugging
5849 engine behind a UI or another front end are encouraged to switch to
5850 using the GDB/MI interface, instead of the old annotations interface
5851 which is now deprecated.
5853 * Support for debugging Pascal programs.
5855 GDB now includes support for debugging Pascal programs. The following
5856 main features are supported:
5858 - Pascal-specific data types such as sets;
5860 - automatic recognition of Pascal sources based on file-name
5863 - Pascal-style display of data types, variables, and functions;
5865 - a Pascal expression parser.
5867 However, some important features are not yet supported.
5869 - Pascal string operations are not supported at all;
5871 - there are some problems with boolean types;
5873 - Pascal type hexadecimal constants are not supported
5874 because they conflict with the internal variables format;
5876 - support for Pascal objects and classes is not full yet;
5878 - unlike Pascal, GDB is case-sensitive for symbol names.
5880 * Changes in completion.
5882 Commands such as `shell', `run' and `set args', which pass arguments
5883 to inferior programs, now complete on file names, similar to what
5884 users expect at the shell prompt.
5886 Commands which accept locations, such as `disassemble', `print',
5887 `breakpoint', `until', etc. now complete on filenames as well as
5888 program symbols. Thus, if you type "break foob TAB", and the source
5889 files linked into the programs include `foobar.c', that file name will
5890 be one of the candidates for completion. However, file names are not
5891 considered for completion after you typed a colon that delimits a file
5892 name from a name of a function in that file, as in "break foo.c:bar".
5894 `set demangle-style' completes on available demangling styles.
5896 * New platform-independent commands:
5898 It is now possible to define a post-hook for a command as well as a
5899 hook that runs before the command. For more details, see the
5900 documentation of `hookpost' in the GDB manual.
5902 * Changes in GNU/Linux native debugging.
5904 Support for debugging multi-threaded programs has been completely
5905 revised for all platforms except m68k and sparc. You can now debug as
5906 many threads as your system allows you to have.
5908 Attach/detach is supported for multi-threaded programs.
5910 Support for SSE registers was added for x86. This doesn't work for
5911 multi-threaded programs though.
5913 * Changes in MIPS configurations.
5915 Multi-arch support is enabled for all MIPS configurations.
5917 GDB can now be built as native debugger on SGI Irix 6.x systems for
5918 debugging n32 executables. (Debugging 64-bit executables is not yet
5921 * Unified support for hardware watchpoints in all x86 configurations.
5923 Most (if not all) native x86 configurations support hardware-assisted
5924 breakpoints and watchpoints in a unified manner. This support
5925 implements debug register sharing between watchpoints, which allows to
5926 put a virtually infinite number of watchpoints on the same address,
5927 and also supports watching regions up to 16 bytes with several debug
5930 The new maintenance command `maintenance show-debug-regs' toggles
5931 debugging print-outs in functions that insert, remove, and test
5932 watchpoints and hardware breakpoints.
5934 * Changes in the DJGPP native configuration.
5936 New command ``info dos sysinfo'' displays assorted information about
5937 the CPU, OS, memory, and DPMI server.
5939 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5940 display information about segment descriptors stored in GDT, LDT, and
5943 New commands ``info dos pde'' and ``info dos pte'' display entries
5944 from Page Directory and Page Tables (for now works with CWSDPMI only).
5945 New command ``info dos address-pte'' displays the Page Table entry for
5946 a given linear address.
5948 GDB can now pass command lines longer than 126 characters to the
5949 program being debugged (requires an update to the libdbg.a library
5950 which is part of the DJGPP development kit).
5952 DWARF2 debug info is now supported.
5954 It is now possible to `step' and `next' through calls to `longjmp'.
5956 * Changes in documentation.
5958 All GDB documentation was converted to GFDL, the GNU Free
5959 Documentation License.
5961 Tracepoints-related commands are now fully documented in the GDB
5964 TUI, the Text-mode User Interface, is now documented in the manual.
5966 Tracepoints-related commands are now fully documented in the GDB
5969 The "GDB Internals" manual now has an index. It also includes
5970 documentation of `ui_out' functions, GDB coding standards, x86
5971 hardware watchpoints, and memory region attributes.
5973 * GDB's version number moved to ``version.in''
5975 The Makefile variable VERSION has been replaced by the file
5976 ``version.in''. People creating GDB distributions should update the
5977 contents of this file.
5981 GUD support is now a standard part of the EMACS distribution.
5983 *** Changes in GDB 5.0:
5985 * Improved support for debugging FP programs on x86 targets
5987 Unified and much-improved support for debugging floating-point
5988 programs on all x86 targets. In particular, ``info float'' now
5989 displays the FP registers in the same format on all x86 targets, with
5990 greater level of detail.
5992 * Improvements and bugfixes in hardware-assisted watchpoints
5994 It is now possible to watch array elements, struct members, and
5995 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5996 on x86 targets no longer erroneously trigger when the address is
5999 * Improvements in the native DJGPP version of GDB
6001 The distribution now includes all the scripts and auxiliary files
6002 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6003 machines ``out of the box''.
6005 The DJGPP version can now debug programs that use signals. It is
6006 possible to catch signals that happened in the debuggee, deliver
6007 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6008 would kill the program being debugged.) Programs that hook hardware
6009 interrupts (keyboard, timer, etc.) can also be debugged.
6011 It is now possible to debug DJGPP programs that redirect their
6012 standard handles or switch them to raw (as opposed to cooked) mode, or
6013 even close them. The command ``run < foo > bar'' works as expected,
6014 and ``info terminal'' reports useful information about the debuggee's
6015 terminal, including raw/cooked mode, redirection, etc.
6017 The DJGPP version now uses termios functions for console I/O, which
6018 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6021 DOS-style file names with drive letters are now fully supported by
6024 It is now possible to debug DJGPP programs that switch their working
6025 directory. It is also possible to rerun the debuggee any number of
6026 times without restarting GDB; thus, you can use the same setup,
6027 breakpoints, etc. for many debugging sessions.
6029 * New native configurations
6031 ARM GNU/Linux arm*-*-linux*
6032 PowerPC GNU/Linux powerpc-*-linux*
6036 Motorola MCore mcore-*-*
6037 x86 VxWorks i[3456]86-*-vxworks*
6038 PowerPC VxWorks powerpc-*-vxworks*
6039 TI TMS320C80 tic80-*-*
6041 * OBSOLETE configurations
6043 Altos 3068 m68*-altos-*
6044 Convex c1-*-*, c2-*-*
6046 ARM RISCix arm-*-* (as host)
6049 Configurations that have been declared obsolete will be commented out,
6050 but the code will be left in place. If there is no activity to revive
6051 these configurations before the next release of GDB, the sources will
6052 be permanently REMOVED.
6054 * Gould support removed
6056 Support for the Gould PowerNode and NP1 has been removed.
6058 * New features for SVR4
6060 On SVR4 native platforms (such as Solaris), if you attach to a process
6061 without first loading a symbol file, GDB will now attempt to locate and
6062 load symbols from the running process's executable file.
6064 * Many C++ enhancements
6066 C++ support has been greatly improved. Overload resolution now works properly
6067 in almost all cases. RTTI support is on the way.
6069 * Remote targets can connect to a sub-program
6071 A popen(3) style serial-device has been added. This device starts a
6072 sub-process (such as a stand-alone simulator) and then communicates
6073 with that. The sub-program to run is specified using the syntax
6074 ``|<program> <args>'' vis:
6076 (gdb) set remotedebug 1
6077 (gdb) target extended-remote |mn10300-elf-sim program-args
6079 * MIPS 64 remote protocol
6081 A long standing bug in the mips64 remote protocol where by GDB
6082 expected certain 32 bit registers (ex SR) to be transfered as 32
6083 instead of 64 bits has been fixed.
6085 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6086 added to provide backward compatibility with older versions of GDB.
6088 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6090 The command ``set remotebinarydownload'' command has been replaced by
6091 ``set remote X-packet''. Other commands in ``set remote'' family
6092 include ``set remote P-packet''.
6094 * Breakpoint commands accept ranges.
6096 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6097 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6098 ``tracepoint passcount'' also accepts a range of tracepoints.
6100 * ``apropos'' command added.
6102 The ``apropos'' command searches through command names and
6103 documentation strings, printing out matches, making it much easier to
6104 try to find a command that does what you are looking for.
6108 A new machine oriented interface (MI) has been added to GDB. This
6109 interface is designed for debug environments running GDB as a separate
6110 process. This is part of the long term libGDB project. See the
6111 "GDB/MI" chapter of the GDB manual for further information. It can be
6112 enabled by configuring with:
6114 .../configure --enable-gdbmi
6116 *** Changes in GDB-4.18:
6118 * New native configurations
6120 HP-UX 10.20 hppa*-*-hpux10.20
6121 HP-UX 11.x hppa*-*-hpux11.0*
6122 M68K GNU/Linux m68*-*-linux*
6126 Fujitsu FR30 fr30-*-elf*
6127 Intel StrongARM strongarm-*-*
6128 Mitsubishi D30V d30v-*-*
6130 * OBSOLETE configurations
6132 Gould PowerNode, NP1 np1-*-*, pn-*-*
6134 Configurations that have been declared obsolete will be commented out,
6135 but the code will be left in place. If there is no activity to revive
6136 these configurations before the next release of GDB, the sources will
6137 be permanently REMOVED.
6141 As a compatibility experiment, GDB's source files buildsym.h and
6142 buildsym.c have been converted to pure standard C, no longer
6143 containing any K&R compatibility code. We believe that all systems in
6144 use today either come with a standard C compiler, or have a GCC port
6145 available. If this is not true, please report the affected
6146 configuration to bug-gdb@gnu.org immediately. See the README file for
6147 information about getting a standard C compiler if you don't have one
6152 GDB now uses readline 2.2.
6154 * set extension-language
6156 You can now control the mapping between filename extensions and source
6157 languages by using the `set extension-language' command. For instance,
6158 you can ask GDB to treat .c files as C++ by saying
6159 set extension-language .c c++
6160 The command `info extensions' lists all of the recognized extensions
6161 and their associated languages.
6163 * Setting processor type for PowerPC and RS/6000
6165 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6166 you can use the `set processor' command to specify what variant of the
6167 PowerPC family you are debugging. The command
6171 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6172 following PowerPC and RS6000 variants:
6174 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6175 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6177 403GC IBM PowerPC 403GC
6178 505 Motorola PowerPC 505
6179 860 Motorola PowerPC 860 or 850
6180 601 Motorola PowerPC 601
6181 602 Motorola PowerPC 602
6182 603 Motorola/IBM PowerPC 603 or 603e
6183 604 Motorola PowerPC 604 or 604e
6184 750 Motorola/IBM PowerPC 750 or 750
6186 At the moment, this command just tells GDB what to name the
6187 special-purpose processor registers. Since almost all the affected
6188 registers are inaccessible to user-level programs, this command is
6189 only useful for remote debugging in its present form.
6193 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6194 more extensive support for HP-UX. Added features include shared
6195 library support, kernel threads and hardware watchpoints for 11.00,
6196 support for HP's ANSI C and C++ compilers, and a compatibility mode
6197 for xdb and dbx commands.
6201 HP's donation includes the new concept of catchpoints, which is a
6202 generalization of the old catch command. On HP-UX, it is now possible
6203 to catch exec, fork, and vfork, as well as library loading.
6205 This means that the existing catch command has changed; its first
6206 argument now specifies the type of catch to be set up. See the
6207 output of "help catch" for a list of catchpoint types.
6209 * Debugging across forks
6211 On HP-UX, you can choose which process to debug when a fork() happens
6216 HP has donated a curses-based terminal user interface (TUI). To get
6217 it, build with --enable-tui. Although this can be enabled for any
6218 configuration, at present it only works for native HP debugging.
6220 * GDB remote protocol additions
6222 A new protocol packet 'X' that writes binary data is now available.
6223 Default behavior is to try 'X', then drop back to 'M' if the stub
6224 fails to respond. The settable variable `remotebinarydownload'
6225 allows explicit control over the use of 'X'.
6227 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6228 full 64-bit address. The command
6230 set remoteaddresssize 32
6232 can be used to revert to the old behaviour. For existing remote stubs
6233 the change should not be noticed, as the additional address information
6236 In order to assist in debugging stubs, you may use the maintenance
6237 command `packet' to send any text string to the stub. For instance,
6239 maint packet heythere
6241 sends the packet "$heythere#<checksum>". Note that it is very easy to
6242 disrupt a debugging session by sending the wrong packet at the wrong
6245 The compare-sections command allows you to compare section data on the
6246 target to what is in the executable file without uploading or
6247 downloading, by comparing CRC checksums.
6249 * Tracing can collect general expressions
6251 You may now collect general expressions at tracepoints. This requires
6252 further additions to the target-side stub; see tracepoint.c and
6253 doc/agentexpr.texi for further details.
6255 * mask-address variable for Mips
6257 For Mips targets, you may control the zeroing of the upper 32 bits of
6258 a 64-bit address by entering `set mask-address on'. This is mainly
6259 of interest to users of embedded R4xxx and R5xxx processors.
6261 * Higher serial baud rates
6263 GDB's serial code now allows you to specify baud rates 57600, 115200,
6264 230400, and 460800 baud. (Note that your host system may not be able
6265 to achieve all of these rates.)
6269 The i960 configuration now includes an initial implementation of a
6270 builtin simulator, contributed by Jim Wilson.
6273 *** Changes in GDB-4.17:
6275 * New native configurations
6277 Alpha GNU/Linux alpha*-*-linux*
6278 Unixware 2.x i[3456]86-unixware2*
6279 Irix 6.x mips*-sgi-irix6*
6280 PowerPC GNU/Linux powerpc-*-linux*
6281 PowerPC Solaris powerpcle-*-solaris*
6282 Sparc GNU/Linux sparc-*-linux*
6283 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6287 Argonaut Risc Chip (ARC) arc-*-*
6288 Hitachi H8/300S h8300*-*-*
6289 Matsushita MN10200 w/simulator mn10200-*-*
6290 Matsushita MN10300 w/simulator mn10300-*-*
6291 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6292 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6293 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6294 Mitsubishi D10V w/simulator d10v-*-*
6295 Mitsubishi M32R/D w/simulator m32r-*-elf*
6296 Tsqware Sparclet sparclet-*-*
6297 NEC V850 w/simulator v850-*-*
6299 * New debugging protocols
6301 ARM with RDI protocol arm*-*-*
6302 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6303 DDB and LSI variants of PMON protocol mips*-*-*
6304 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6305 PowerPC with SDS protocol powerpc{,le}-*-eabi
6306 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6310 All configurations can now understand and use the DWARF 2 debugging
6311 format. The choice is automatic, if the symbol file contains DWARF 2
6316 GDB now includes basic Java language support. This support is
6317 only useful with Java compilers that produce native machine code.
6319 * solib-absolute-prefix and solib-search-path
6321 For SunOS and SVR4 shared libraries, you may now set the prefix for
6322 loading absolute shared library symbol files, and the search path for
6323 locating non-absolute shared library symbol files.
6325 * Live range splitting
6327 GDB can now effectively debug code for which GCC has performed live
6328 range splitting as part of its optimization. See gdb/doc/LRS for
6329 more details on the expected format of the stabs information.
6333 GDB's support for the GNU Hurd, including thread debugging, has been
6334 updated to work with current versions of the Hurd.
6338 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6339 instruction set. ARM GDB automatically detects when Thumb
6340 instructions are in use, and adjusts disassembly and backtracing
6345 GDB's MIPS target configurations now handle the MIP16 16-bit
6350 GDB now includes support for overlays; if an executable has been
6351 linked such that multiple sections are based at the same address, GDB
6352 will decide which section to use for symbolic info. You can choose to
6353 control the decision manually, using overlay commands, or implement
6354 additional target-side support and use "overlay load-target" to bring
6355 in the overlay mapping. Do "help overlay" for more detail.
6359 The command "info symbol <address>" displays information about
6360 the symbol at the specified address.
6364 The standard remote protocol now includes an extension that allows
6365 asynchronous collection and display of trace data. This requires
6366 extensive support in the target-side debugging stub. Tracing mode
6367 includes a new interaction mode in GDB and new commands: see the
6368 file tracepoint.c for more details.
6372 Configurations for embedded MIPS now include a simulator contributed
6373 by Cygnus Solutions. The simulator supports the instruction sets
6374 of most MIPS variants.
6378 Sparc configurations may now include the ERC32 simulator contributed
6379 by the European Space Agency. The simulator is not built into
6380 Sparc targets by default; configure with --enable-sim to include it.
6384 For target configurations that may include multiple variants of a
6385 basic architecture (such as MIPS and SH), you may now set the
6386 architecture explicitly. "set arch" sets, "info arch" lists
6387 the possible architectures.
6389 *** Changes in GDB-4.16:
6391 * New native configurations
6393 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6394 M68K NetBSD m68k-*-netbsd*
6395 PowerPC AIX 4.x powerpc-*-aix*
6396 PowerPC MacOS powerpc-*-macos*
6397 PowerPC Windows NT powerpcle-*-cygwin32
6398 RS/6000 AIX 4.x rs6000-*-aix4*
6402 ARM with RDP protocol arm-*-*
6403 I960 with MON960 i960-*-coff
6404 MIPS VxWorks mips*-*-vxworks*
6405 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6406 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6408 Matra Sparclet sparclet-*-*
6412 The powerpc-eabi configuration now includes the PSIM simulator,
6413 contributed by Andrew Cagney, with assistance from Mike Meissner.
6414 PSIM is a very elaborate model of the PowerPC, including not only
6415 basic instruction set execution, but also details of execution unit
6416 performance and I/O hardware. See sim/ppc/README for more details.
6420 GDB now works with Solaris 2.5.
6422 * Windows 95/NT native
6424 GDB will now work as a native debugger on Windows 95 and Windows NT.
6425 To build it from source, you must use the "gnu-win32" environment,
6426 which uses a DLL to emulate enough of Unix to run the GNU tools.
6427 Further information, binaries, and sources are available at
6428 ftp.cygnus.com, under pub/gnu-win32.
6430 * dont-repeat command
6432 If a user-defined command includes the command `dont-repeat', then the
6433 command will not be repeated if the user just types return. This is
6434 useful if the command is time-consuming to run, so that accidental
6435 extra keystrokes don't run the same command many times.
6437 * Send break instead of ^C
6439 The standard remote protocol now includes an option to send a break
6440 rather than a ^C to the target in order to interrupt it. By default,
6441 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6443 * Remote protocol timeout
6445 The standard remote protocol includes a new variable `remotetimeout'
6446 that allows you to set the number of seconds before GDB gives up trying
6447 to read from the target. The default value is 2.
6449 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6451 By default GDB will automatically keep track of objects as they are
6452 loaded and unloaded by the dynamic linker. By using the command `set
6453 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6454 when shared library events occur, thus allowing you to set breakpoints
6455 in shared libraries which are explicitly loaded by the inferior.
6457 Note this feature does not work on hpux8. On hpux9 you must link
6458 /usr/lib/end.o into your program. This feature should work
6459 automatically on hpux10.
6461 * Irix 5.x hardware watchpoint support
6463 Irix 5 configurations now support the use of hardware watchpoints.
6465 * Mips protocol "SYN garbage limit"
6467 When debugging a Mips target using the `target mips' protocol, you
6468 may set the number of characters that GDB will ignore by setting
6469 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6470 every character. The default value is 1050.
6472 * Recording and replaying remote debug sessions
6474 If you set `remotelogfile' to the name of a file, gdb will write to it
6475 a recording of a remote debug session. This recording may then be
6476 replayed back to gdb using "gdbreplay". See gdbserver/README for
6477 details. This is useful when you have a problem with GDB while doing
6478 remote debugging; you can make a recording of the session and send it
6479 to someone else, who can then recreate the problem.
6481 * Speedups for remote debugging
6483 GDB includes speedups for downloading and stepping MIPS systems using
6484 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6485 and more efficient S-record downloading.
6487 * Memory use reductions and statistics collection
6489 GDB now uses less memory and reports statistics about memory usage.
6490 Try the `maint print statistics' command, for example.
6492 *** Changes in GDB-4.15:
6494 * Psymtabs for XCOFF
6496 The symbol reader for AIX GDB now uses partial symbol tables. This
6497 can greatly improve startup time, especially for large executables.
6499 * Remote targets use caching
6501 Remote targets now use a data cache to speed up communication with the
6502 remote side. The data cache could lead to incorrect results because
6503 it doesn't know about volatile variables, thus making it impossible to
6504 debug targets which use memory mapped I/O devices. `set remotecache
6505 off' turns the the data cache off.
6507 * Remote targets may have threads
6509 The standard remote protocol now includes support for multiple threads
6510 in the target system, using new protocol commands 'H' and 'T'. See
6511 gdb/remote.c for details.
6515 If GDB is configured with `--enable-netrom', then it will include
6516 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6517 acts as though it is a bank of ROM on the target board, but you can
6518 write into it over the network. GDB's support consists only of
6519 support for fast loading into the emulated ROM; to debug, you must use
6520 another protocol, such as standard remote protocol. The usual
6521 sequence is something like
6523 target nrom <netrom-hostname>
6525 target remote <netrom-hostname>:1235
6529 GDB now includes support for the Apple Macintosh, as a host only. It
6530 may be run as either an MPW tool or as a standalone application, and
6531 it can debug through the serial port. All the usual GDB commands are
6532 available, but to the target command, you must supply "serial" as the
6533 device type instead of "/dev/ttyXX". See mpw-README in the main
6534 directory for more information on how to build. The MPW configuration
6535 scripts */mpw-config.in support only a few targets, and only the
6536 mips-idt-ecoff target has been tested.
6540 GDB configuration now uses autoconf. This is not user-visible,
6541 but does simplify configuration and building.
6545 GDB now supports hpux10.
6547 *** Changes in GDB-4.14:
6549 * New native configurations
6551 x86 FreeBSD i[345]86-*-freebsd
6552 x86 NetBSD i[345]86-*-netbsd
6553 NS32k NetBSD ns32k-*-netbsd
6554 Sparc NetBSD sparc-*-netbsd
6558 A29K VxWorks a29k-*-vxworks
6559 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6560 CPU32 EST-300 emulator m68*-*-est*
6561 PowerPC ELF powerpc-*-elf
6564 * Alpha OSF/1 support for procfs
6566 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6567 possible to attach to running processes. As the mounting of the /proc
6568 filesystem is optional on the Alpha, GDB automatically determines
6569 the availability of /proc during startup. This can lead to problems
6570 if /proc is unmounted after GDB has been started.
6572 * Arguments to user-defined commands
6574 User commands may accept up to 10 arguments separated by whitespace.
6575 Arguments are accessed within the user command via $arg0..$arg9. A
6578 print $arg0 + $arg1 + $arg2
6580 To execute the command use:
6583 Defines the command "adder" which prints the sum of its three arguments.
6584 Note the arguments are text substitutions, so they may reference variables,
6585 use complex expressions, or even perform inferior function calls.
6587 * New `if' and `while' commands
6589 This makes it possible to write more sophisticated user-defined
6590 commands. Both commands take a single argument, which is the
6591 expression to evaluate, and must be followed by the commands to
6592 execute, one per line, if the expression is nonzero, the list being
6593 terminated by the word `end'. The `if' command list may include an
6594 `else' word, which causes the following commands to be executed only
6595 if the expression is zero.
6597 * Fortran source language mode
6599 GDB now includes partial support for Fortran 77. It will recognize
6600 Fortran programs and can evaluate a subset of Fortran expressions, but
6601 variables and functions may not be handled correctly. GDB will work
6602 with G77, but does not yet know much about symbols emitted by other
6605 * Better HPUX support
6607 Most debugging facilities now work on dynamic executables for HPPAs
6608 running hpux9 or later. You can attach to running dynamically linked
6609 processes, but by default the dynamic libraries will be read-only, so
6610 for instance you won't be able to put breakpoints in them. To change
6611 that behavior do the following before running the program:
6617 This will cause the libraries to be mapped private and read-write.
6618 To revert to the normal behavior, do this:
6624 You cannot set breakpoints or examine data in the library until after
6625 the library is loaded if the function/data symbols do not have
6628 GDB can now also read debug symbols produced by the HP C compiler on
6629 HPPAs (sorry, no C++, Fortran or 68k support).
6631 * Target byte order now dynamically selectable
6633 You can choose which byte order to use with a target system, via the
6634 commands "set endian big" and "set endian little", and you can see the
6635 current setting by using "show endian". You can also give the command
6636 "set endian auto", in which case GDB will use the byte order
6637 associated with the executable. Currently, only embedded MIPS
6638 configurations support dynamic selection of target byte order.
6640 * New DOS host serial code
6642 This version uses DPMI interrupts to handle buffered I/O, so you
6643 no longer need to run asynctsr when debugging boards connected to
6646 *** Changes in GDB-4.13:
6648 * New "complete" command
6650 This lists all the possible completions for the rest of the line, if it
6651 were to be given as a command itself. This is intended for use by emacs.
6653 * Trailing space optional in prompt
6655 "set prompt" no longer adds a space for you after the prompt you set. This
6656 allows you to set a prompt which ends in a space or one that does not.
6658 * Breakpoint hit counts
6660 "info break" now displays a count of the number of times the breakpoint
6661 has been hit. This is especially useful in conjunction with "ignore"; you
6662 can ignore a large number of breakpoint hits, look at the breakpoint info
6663 to see how many times the breakpoint was hit, then run again, ignoring one
6664 less than that number, and this will get you quickly to the last hit of
6667 * Ability to stop printing at NULL character
6669 "set print null-stop" will cause GDB to stop printing the characters of
6670 an array when the first NULL is encountered. This is useful when large
6671 arrays actually contain only short strings.
6673 * Shared library breakpoints
6675 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6676 breakpoints in shared libraries before the executable is run.
6678 * Hardware watchpoints
6680 There is a new hardware breakpoint for the watch command for sparclite
6681 targets. See gdb/sparclite/hw_breakpoint.note.
6683 Hardware watchpoints are also now supported under GNU/Linux.
6687 Annotations have been added. These are for use with graphical interfaces,
6688 and are still experimental. Currently only gdba.el uses these.
6690 * Improved Irix 5 support
6692 GDB now works properly with Irix 5.2.
6694 * Improved HPPA support
6696 GDB now works properly with the latest GCC and GAS.
6698 * New native configurations
6700 Sequent PTX4 i[34]86-sequent-ptx4
6701 HPPA running OSF/1 hppa*-*-osf*
6702 Atari TT running SVR4 m68*-*-sysv4*
6703 RS/6000 LynxOS rs6000-*-lynxos*
6707 OS/9000 i[34]86-*-os9k
6708 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6711 * Hitachi SH7000 and E7000-PC ICE support
6713 There is now support for communicating with the Hitachi E7000-PC ICE.
6714 This is available automatically when GDB is configured for the SH.
6718 As usual, a variety of small fixes and improvements, both generic
6719 and configuration-specific. See the ChangeLog for more detail.
6721 *** Changes in GDB-4.12:
6723 * Irix 5 is now supported
6727 GDB-4.12 on the HPPA has a number of changes which make it unable
6728 to debug the output from the currently released versions of GCC and
6729 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6730 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6731 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6734 *** Changes in GDB-4.11:
6736 * User visible changes:
6740 The "set remotedebug" option is now consistent between the mips remote
6741 target, remote targets using the gdb-specific protocol, UDI (AMD's
6742 debug protocol for the 29k) and the 88k bug monitor. It is now an
6743 integer specifying a debug level (normally 0 or 1, but 2 means more
6744 debugging info for the mips target).
6746 * DEC Alpha native support
6748 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6749 debug info, but GDB works fairly well with the DEC compiler and should
6750 work with a future GCC release. See the README file for a few
6751 Alpha-specific notes.
6753 * Preliminary thread implementation
6755 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6757 * LynxOS native and target support for 386
6759 This release has been hosted on LynxOS 2.2, and also can be configured
6760 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6763 * Improvements in C++ mangling/demangling.
6765 This release has much better g++ debugging, specifically in name
6766 mangling/demangling, virtual function calls, print virtual table,
6767 call methods, ...etc.
6769 *** Changes in GDB-4.10:
6771 * User visible changes:
6773 Remote debugging using the GDB-specific (`target remote') protocol now
6774 supports the `load' command. This is only useful if you have some
6775 other way of getting the stub to the target system, and you can put it
6776 somewhere in memory where it won't get clobbered by the download.
6778 Filename completion now works.
6780 When run under emacs mode, the "info line" command now causes the
6781 arrow to point to the line specified. Also, "info line" prints
6782 addresses in symbolic form (as well as hex).
6784 All vxworks based targets now support a user settable option, called
6785 vxworks-timeout. This option represents the number of seconds gdb
6786 should wait for responses to rpc's. You might want to use this if
6787 your vxworks target is, perhaps, a slow software simulator or happens
6788 to be on the far side of a thin network line.
6792 This release contains support for using a DEC alpha as a GDB host for
6793 cross debugging. Native alpha debugging is not supported yet.
6796 *** Changes in GDB-4.9:
6800 This is the first GDB release which is accompanied by a matching testsuite.
6801 The testsuite requires installation of dejagnu, which should be available
6802 via ftp from most sites that carry GNU software.
6806 'Cfront' style demangling has had its name changed to 'ARM' style, to
6807 emphasize that it was written from the specifications in the C++ Annotated
6808 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6809 disclaimers, it still generated too much confusion with users attempting to
6810 use gdb with AT&T cfront.
6814 GDB now uses a standard remote interface to a simulator library.
6815 So far, the library contains simulators for the Zilog Z8001/2, the
6816 Hitachi H8/300, H8/500 and Super-H.
6818 * New targets supported
6820 H8/300 simulator h8300-hitachi-hms or h8300hms
6821 H8/500 simulator h8500-hitachi-hms or h8500hms
6822 SH simulator sh-hitachi-hms or sh
6823 Z8000 simulator z8k-zilog-none or z8ksim
6824 IDT MIPS board over serial line mips-idt-ecoff
6826 Cross-debugging to GO32 targets is supported. It requires a custom
6827 version of the i386-stub.c module which is integrated with the
6828 GO32 memory extender.
6830 * New remote protocols
6832 MIPS remote debugging protocol.
6834 * New source languages supported
6836 This version includes preliminary support for Chill, a Pascal like language
6837 used by telecommunications companies. Chill support is also being integrated
6838 into the GNU compiler, but we don't know when it will be publically available.
6841 *** Changes in GDB-4.8:
6843 * HP Precision Architecture supported
6845 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6846 version of this support was available as a set of patches from the
6847 University of Utah. GDB does not support debugging of programs
6848 compiled with the HP compiler, because HP will not document their file
6849 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6850 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6852 Many problems in the preliminary version have been fixed.
6854 * Faster and better demangling
6856 We have improved template demangling and fixed numerous bugs in the GNU style
6857 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6858 character types (wchar_t) are now supported. Demangling of each symbol is now
6859 only done once, and is cached when the symbol table for a file is read in.
6860 This results in a small increase in memory usage for C programs, a moderate
6861 increase in memory usage for C++ programs, and a fantastic speedup in
6864 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6865 from the specifications in the Annotated Reference Manual, which AT&T's
6866 compiler does not actually implement.
6868 * G++ multiple inheritance compiler problem
6870 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6871 inheritance lattices was reworked to properly discover ambiguities. We
6872 recently found an example which causes this new algorithm to fail in a
6873 very subtle way, producing bad debug information for those classes.
6874 The file 'gcc.patch' (in this directory) can be applied to gcc to
6875 circumvent the problem. A future GCC release will contain a complete
6878 The previous G++ debug info problem (mentioned below for the gdb-4.7
6879 release) is fixed in gcc version 2.3.2.
6881 * Improved configure script
6883 The `configure' script will now attempt to guess your system type if
6884 you don't supply a host system type. The old scheme of supplying a
6885 host system triplet is preferable over using this. All the magic is
6886 done in the new `config.guess' script. Examine it for details.
6888 We have also brought our configure script much more in line with the FSF's
6889 version. It now supports the --with-xxx options. In particular,
6890 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6891 The resulting GDB will not be able to read arbitrary object file formats --
6892 only the format ``expected'' to be used on the configured target system.
6893 We hope to make this the default in a future release.
6895 * Documentation improvements
6897 There's new internal documentation on how to modify GDB, and how to
6898 produce clean changes to the code. We implore people to read it
6899 before submitting changes.
6901 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6902 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6903 `info' files are also provided. To build `info' files from scratch,
6904 you will need the latest `makeinfo' release, which will be available in
6905 a future texinfo-X.Y release.
6907 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6908 We're not sure exactly which versions have this problem, but it has
6909 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6910 or better. If that isn't possible, there is a patch in
6911 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6912 around this problem.
6916 GDB now supports array constants that can be used in expressions typed in by
6917 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6918 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6921 The new directory `gdb/sparclite' contains a program that demonstrates
6922 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6924 * New native hosts supported
6926 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6927 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6929 * New targets supported
6931 AMD 29k family via UDI a29k-amd-udi or udi29k
6933 * New file formats supported
6935 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6936 HPUX core files, and SCO 3.2v2 core files.
6940 Attaching to processes now works again; thanks for the many bug reports.
6942 We have also stomped on a bunch of core dumps caused by
6943 printf_filtered("%s") problems.
6945 We eliminated a copyright problem on the rpc and ptrace header files
6946 for VxWorks, which was discovered at the last minute during the 4.7
6947 release. You should now be able to build a VxWorks GDB.
6949 You can now interrupt gdb while an attached process is running. This
6950 will cause the attached process to stop, and give control back to GDB.
6952 We fixed problems caused by using too many file descriptors
6953 for reading symbols from object files and libraries. This was
6954 especially a problem for programs that used many (~100) shared
6957 The `step' command now only enters a subroutine if there is line number
6958 information for the subroutine. Otherwise it acts like the `next'
6959 command. Previously, `step' would enter subroutines if there was
6960 any debugging information about the routine. This avoids problems
6961 when using `cc -g1' on MIPS machines.
6963 * Internal improvements
6965 GDB's internal interfaces have been improved to make it easier to support
6966 debugging of multiple languages in the future.
6968 GDB now uses a common structure for symbol information internally.
6969 Minimal symbols (derived from linkage symbols in object files), partial
6970 symbols (from a quick scan of debug information), and full symbols
6971 contain a common subset of information, making it easier to write
6972 shared code that handles any of them.
6974 * New command line options
6976 We now accept --silent as an alias for --quiet.
6980 The memory-mapped-malloc library is now licensed under the GNU Library
6981 General Public License.
6983 *** Changes in GDB-4.7:
6985 * Host/native/target split
6987 GDB has had some major internal surgery to untangle the support for
6988 hosts and remote targets. Now, when you configure GDB for a remote
6989 target, it will no longer load in all of the support for debugging
6990 local programs on the host. When fully completed and tested, this will
6991 ensure that arbitrary host/target combinations are possible.
6993 The primary conceptual shift is to separate the non-portable code in
6994 GDB into three categories. Host specific code is required any time GDB
6995 is compiled on that host, regardless of the target. Target specific
6996 code relates to the peculiarities of the target, but can be compiled on
6997 any host. Native specific code is everything else: it can only be
6998 built when the host and target are the same system. Child process
6999 handling and core file support are two common `native' examples.
7001 GDB's use of /proc for controlling Unix child processes is now cleaner.
7002 It has been split out into a single module under the `target_ops' vector,
7003 plus two native-dependent functions for each system that uses /proc.
7005 * New hosts supported
7007 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7008 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7009 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7011 * New targets supported
7013 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7014 68030 and CPU32 m68030-*-*, m68332-*-*
7016 * New native hosts supported
7018 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7019 (386bsd is not well tested yet)
7020 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7022 * New file formats supported
7024 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7025 supports reading of `a.out.adobe' object files, which are an a.out
7026 format extended with minimal information about multiple sections.
7030 `show copying' is the same as the old `info copying'.
7031 `show warranty' is the same as `info warrantee'.
7032 These were renamed for consistency. The old commands continue to work.
7034 `info handle' is a new alias for `info signals'.
7036 You can now define pre-command hooks, which attach arbitrary command
7037 scripts to any command. The commands in the hook will be executed
7038 prior to the user's command. You can also create a hook which will be
7039 executed whenever the program stops. See gdb.texinfo.
7043 We now deal with Cfront style name mangling, and can even extract type
7044 info from mangled symbols. GDB can automatically figure out which
7045 symbol mangling style your C++ compiler uses.
7047 Calling of methods and virtual functions has been improved as well.
7051 The crash that occured when debugging Sun Ansi-C compiled binaries is
7052 fixed. This was due to mishandling of the extra N_SO stabs output
7055 We also finally got Ultrix 4.2 running in house, and fixed core file
7056 support, with help from a dozen people on the net.
7058 John M. Farrell discovered that the reason that single-stepping was so
7059 slow on all of the Mips based platforms (primarily SGI and DEC) was
7060 that we were trying to demangle and lookup a symbol used for internal
7061 purposes on every instruction that was being stepped through. Changing
7062 the name of that symbol so that it couldn't be mistaken for a C++
7063 mangled symbol sped things up a great deal.
7065 Rich Pixley sped up symbol lookups in general by getting much smarter
7066 about when C++ symbol mangling is necessary. This should make symbol
7067 completion (TAB on the command line) much faster. It's not as fast as
7068 we'd like, but it's significantly faster than gdb-4.6.
7072 A new user controllable variable 'call_scratch_address' can
7073 specify the location of a scratch area to be used when GDB
7074 calls a function in the target. This is necessary because the
7075 usual method of putting the scratch area on the stack does not work
7076 in systems that have separate instruction and data spaces.
7078 We integrated changes to support the 29k UDI (Universal Debugger
7079 Interface), but discovered at the last minute that we didn't have all
7080 of the appropriate copyright paperwork. We are working with AMD to
7081 resolve this, and hope to have it available soon.
7085 We have sped up the remote serial line protocol, especially for targets
7086 with lots of registers. It now supports a new `expedited status' ('T')
7087 message which can be used in place of the existing 'S' status message.
7088 This allows the remote stub to send only the registers that GDB
7089 needs to make a quick decision about single-stepping or conditional
7090 breakpoints, eliminating the need to fetch the entire register set for
7091 each instruction being stepped through.
7093 The GDB remote serial protocol now implements a write-through cache for
7094 registers, only re-reading the registers if the target has run.
7096 There is also a new remote serial stub for SPARC processors. You can
7097 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7098 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7099 processor with a serial port.
7103 Configure.in files have become much easier to read and modify. A new
7104 `table driven' format makes it more obvious what configurations are
7105 supported, and what files each one uses.
7109 There is a new opcodes library which will eventually contain all of the
7110 disassembly routines and opcode tables. At present, it only contains
7111 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7112 disassembler (binutils/objdump) to share these routines.
7114 The libiberty library is now copylefted under the GNU Library General
7115 Public License. This allows more liberal use, and was done so libg++
7116 can use it. This makes no difference to GDB, since the Library License
7117 grants all the rights from the General Public License.
7121 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7122 reference to the stabs symbol info used by the debugger. It is (as far
7123 as we know) the only published document on this fascinating topic. We
7124 encourage you to read it, compare it to the stabs information on your
7125 system, and send improvements on the document in general (to
7126 bug-gdb@prep.ai.mit.edu).
7128 And, of course, many bugs have been fixed.
7131 *** Changes in GDB-4.6:
7133 * Better support for C++ function names
7135 GDB now accepts as input the "demangled form" of C++ overloaded function
7136 names and member function names, and can do command completion on such names
7137 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7138 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7139 Make use of command completion, it is your friend.
7141 GDB also now accepts a variety of C++ mangled symbol formats. They are
7142 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7143 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7144 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7145 for the list of formats.
7147 * G++ symbol mangling problem
7149 Recent versions of gcc have a bug in how they emit debugging information for
7150 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7151 directory) can be applied to gcc to fix the problem. Alternatively, if you
7152 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7153 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7154 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7157 * New 'maintenance' command
7159 All of the commands related to hacking GDB internals have been moved out of
7160 the main command set, and now live behind the 'maintenance' command. This
7161 can also be abbreviated as 'mt'. The following changes were made:
7163 dump-me -> maintenance dump-me
7164 info all-breakpoints -> maintenance info breakpoints
7165 printmsyms -> maintenance print msyms
7166 printobjfiles -> maintenance print objfiles
7167 printpsyms -> maintenance print psymbols
7168 printsyms -> maintenance print symbols
7170 The following commands are new:
7172 maintenance demangle Call internal GDB demangler routine to
7173 demangle a C++ link name and prints the result.
7174 maintenance print type Print a type chain for a given symbol
7176 * Change to .gdbinit file processing
7178 We now read the $HOME/.gdbinit file before processing the argv arguments
7179 (e.g. reading symbol files or core files). This allows global parameters to
7180 be set, which will apply during the symbol reading. The ./.gdbinit is still
7181 read after argv processing.
7183 * New hosts supported
7185 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7187 GNU/Linux support i386-unknown-linux or linux
7189 We are also including code to support the HP/PA running BSD and HPUX. This
7190 is almost guaranteed not to work, as we didn't have time to test or build it
7191 for this release. We are including it so that the more adventurous (or
7192 masochistic) of you can play with it. We also had major problems with the
7193 fact that the compiler that we got from HP doesn't support the -g option.
7196 * New targets supported
7198 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7200 * More smarts about finding #include files
7202 GDB now remembers the compilation directory for all include files, and for
7203 all files from which C is generated (like yacc and lex sources). This
7204 greatly improves GDB's ability to find yacc/lex sources, and include files,
7205 especially if you are debugging your program from a directory different from
7206 the one that contains your sources.
7208 We also fixed a bug which caused difficulty with listing and setting
7209 breakpoints in include files which contain C code. (In the past, you had to
7210 try twice in order to list an include file that you hadn't looked at before.)
7212 * Interesting infernals change
7214 GDB now deals with arbitrary numbers of sections, where the symbols for each
7215 section must be relocated relative to that section's landing place in the
7216 target's address space. This work was needed to support ELF with embedded
7217 stabs used by Solaris-2.0.
7219 * Bug fixes (of course!)
7221 There have been loads of fixes for the following things:
7222 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7223 i960, stabs, DOS(GO32), procfs, etc...
7225 See the ChangeLog for details.
7227 *** Changes in GDB-4.5:
7229 * New machines supported (host and target)
7231 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7233 SGI Irix-4.x mips-sgi-irix4 or iris4
7235 * New malloc package
7237 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7238 Mmalloc is capable of handling mutiple heaps of memory. It is also
7239 capable of saving a heap to a file, and then mapping it back in later.
7240 This can be used to greatly speedup the startup of GDB by using a
7241 pre-parsed symbol table which lives in a mmalloc managed heap. For
7242 more details, please read mmalloc/mmalloc.texi.
7246 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7247 'help info proc' for details.
7249 * MIPS ecoff symbol table format
7251 The code that reads MIPS symbol table format is now supported on all hosts.
7252 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7255 * File name changes for MS-DOS
7257 Many files in the config directories have been renamed to make it easier to
7258 support GDB on MS-DOSe systems (which have very restrictive file name
7259 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7260 environment) is close to working but has some remaining problems. Note
7261 that debugging of DOS programs is not supported, due to limitations
7262 in the ``operating system'', but it can be used to host cross-debugging.
7264 * Cross byte order fixes
7266 Many fixes have been made to support cross debugging of Sparc and MIPS
7267 targets from hosts whose byte order differs.
7269 * New -mapped and -readnow options
7271 If memory-mapped files are available on your system through the 'mmap'
7272 system call, you can use the -mapped option on the `file' or
7273 `symbol-file' commands to cause GDB to write the symbols from your
7274 program into a reusable file. If the program you are debugging is
7275 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7276 Future GDB debugging sessions will notice the presence of this file,
7277 and will quickly map in symbol information from it, rather than reading
7278 the symbol table from the executable program. Using the '-mapped'
7279 option in a GDB `file' or `symbol-file' command has the same effect as
7280 starting GDB with the '-mapped' command-line option.
7282 You can cause GDB to read the entire symbol table immediately by using
7283 the '-readnow' option with any of the commands that load symbol table
7284 information (or on the GDB command line). This makes the command
7285 slower, but makes future operations faster.
7287 The -mapped and -readnow options are typically combined in order to
7288 build a `fred.syms' file that contains complete symbol information.
7289 A simple GDB invocation to do nothing but build a `.syms' file for future
7292 gdb -batch -nx -mapped -readnow programname
7294 The `.syms' file is specific to the host machine on which GDB is run.
7295 It holds an exact image of GDB's internal symbol table. It cannot be
7296 shared across multiple host platforms.
7298 * longjmp() handling
7300 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7301 siglongjmp() without losing control. This feature has not yet been ported to
7302 all systems. It currently works on many 386 platforms, all MIPS-based
7303 platforms (SGI, DECstation, etc), and Sun3/4.
7307 Preliminary work has been put in to support the new Solaris OS from Sun. At
7308 this time, it can control and debug processes, but it is not capable of
7313 As always, many many bug fixes. The major areas were with g++, and mipsread.
7314 People using the MIPS-based platforms should experience fewer mysterious
7315 crashes and trashed symbol tables.
7317 *** Changes in GDB-4.4:
7319 * New machines supported (host and target)
7321 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7323 BSD Reno on Vax vax-dec-bsd
7324 Ultrix on Vax vax-dec-ultrix
7326 * New machines supported (target)
7328 AMD 29000 embedded, using EBMON a29k-none-none
7332 GDB continues to improve its handling of C++. `References' work better.
7333 The demangler has also been improved, and now deals with symbols mangled as
7334 per the Annotated C++ Reference Guide.
7336 GDB also now handles `stabs' symbol information embedded in MIPS
7337 `ecoff' symbol tables. Since the ecoff format was not easily
7338 extensible to handle new languages such as C++, this appeared to be a
7339 good way to put C++ debugging info into MIPS binaries. This option
7340 will be supported in the GNU C compiler, version 2, when it is
7343 * New features for SVR4
7345 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7346 shared libraries. Debugging dynamically linked programs should present
7347 only minor differences from debugging statically linked programs.
7349 The `info proc' command will print out information about any process
7350 on an SVR4 system (including the one you are debugging). At the moment,
7351 it prints the address mappings of the process.
7353 If you bring up GDB on another SVR4 system, please send mail to
7354 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7356 * Better dynamic linking support in SunOS
7358 Reading symbols from shared libraries which contain debugging symbols
7359 now works properly. However, there remain issues such as automatic
7360 skipping of `transfer vector' code during function calls, which
7361 make it harder to debug code in a shared library, than to debug the
7362 same code linked statically.
7366 GDB is now using the latest `getopt' routines from the FSF. This
7367 version accepts the -- prefix for options with long names. GDB will
7368 continue to accept the old forms (-option and +option) as well.
7369 Various single letter abbreviations for options have been explicity
7370 added to the option table so that they won't get overshadowed in the
7371 future by other options that begin with the same letter.
7375 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7376 Many assorted bugs have been handled. Many more remain to be handled.
7377 See the various ChangeLog files (primarily in gdb and bfd) for details.
7380 *** Changes in GDB-4.3:
7382 * New machines supported (host and target)
7384 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7385 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7386 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7388 * Almost SCO Unix support
7390 We had hoped to support:
7391 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7392 (except for core file support), but we discovered very late in the release
7393 that it has problems with process groups that render gdb unusable. Sorry
7394 about that. I encourage people to fix it and post the fixes.
7396 * Preliminary ELF and DWARF support
7398 GDB can read ELF object files on System V Release 4, and can handle
7399 debugging records for C, in DWARF format, in ELF files. This support
7400 is preliminary. If you bring up GDB on another SVR4 system, please
7401 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7406 GDB now uses the latest `readline' library. One user-visible change
7407 is that two tabs will list possible command completions, which previously
7408 required typing M-? (meta-question mark, or ESC ?).
7412 The `stepi' bug that many of you noticed has been squashed.
7413 Many bugs in C++ have been handled. Many more remain to be handled.
7414 See the various ChangeLog files (primarily in gdb and bfd) for details.
7416 * State of the MIPS world (in case you wondered):
7418 GDB can understand the symbol tables emitted by the compilers
7419 supplied by most vendors of MIPS-based machines, including DEC. These
7420 symbol tables are in a format that essentially nobody else uses.
7422 Some versions of gcc come with an assembler post-processor called
7423 mips-tfile. This program is required if you want to do source-level
7424 debugging of gcc-compiled programs. I believe FSF does not ship
7425 mips-tfile with gcc version 1, but it will eventually come with gcc
7428 Debugging of g++ output remains a problem. g++ version 1.xx does not
7429 really support it at all. (If you're lucky, you should be able to get
7430 line numbers and stack traces to work, but no parameters or local
7431 variables.) With some work it should be possible to improve the
7434 When gcc version 2 is released, you will have somewhat better luck.
7435 However, even then you will get confusing results for inheritance and
7438 We will eventually provide full debugging of g++ output on
7439 DECstations. This will probably involve some kind of stabs-in-ecoff
7440 encapulation, but the details have not been worked out yet.
7443 *** Changes in GDB-4.2:
7445 * Improved configuration
7447 Only one copy of `configure' exists now, and it is not self-modifying.
7448 Porting BFD is simpler.
7452 The `step' and `next' commands now only stop at the first instruction
7453 of a source line. This prevents the multiple stops that used to occur
7454 in switch statements, for-loops, etc. `Step' continues to stop if a
7455 function that has debugging information is called within the line.
7459 Lots of small bugs fixed. More remain.
7461 * New host supported (not target)
7463 Intel 386 PC clone running Mach i386-none-mach
7466 *** Changes in GDB-4.1:
7468 * Multiple source language support
7470 GDB now has internal scaffolding to handle several source languages.
7471 It determines the type of each source file from its filename extension,
7472 and will switch expression parsing and number formatting to match the
7473 language of the function in the currently selected stack frame.
7474 You can also specifically set the language to be used, with
7475 `set language c' or `set language modula-2'.
7479 GDB now has preliminary support for the GNU Modula-2 compiler,
7480 currently under development at the State University of New York at
7481 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7482 continue through the fall of 1991 and into 1992.
7484 Other Modula-2 compilers are currently not supported, and attempting to
7485 debug programs compiled with them will likely result in an error as the
7486 symbol table is read. Feel free to work on it, though!
7488 There are hooks in GDB for strict type checking and range checking,
7489 in the `Modula-2 philosophy', but they do not currently work.
7493 GDB can now write to executable and core files (e.g. patch
7494 a variable's value). You must turn this switch on, specify
7495 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7496 by assigning a new value to a variable. Modifications take
7499 * Automatic SunOS shared library reading
7501 When you run your program, GDB automatically determines where its
7502 shared libraries (if any) have been loaded, and reads their symbols.
7503 The `share' command is no longer needed. This also works when
7504 examining core files.
7508 You can specify the number of lines that the `list' command shows.
7511 * New machines supported (host and target)
7513 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7514 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7515 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7517 * New hosts supported (not targets)
7519 IBM RT/PC: romp-ibm-aix or rtpc
7521 * New targets supported (not hosts)
7523 AMD 29000 embedded with COFF a29k-none-coff
7524 AMD 29000 embedded with a.out a29k-none-aout
7525 Ultracomputer remote kernel debug a29k-nyu-kern
7527 * New remote interfaces
7533 *** Changes in GDB-4.0:
7537 Wide output is wrapped at good places to make the output more readable.
7539 Gdb now supports cross-debugging from a host machine of one type to a
7540 target machine of another type. Communication with the target system
7541 is over serial lines. The ``target'' command handles connecting to the
7542 remote system; the ``load'' command will download a program into the
7543 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7544 also supports debugging of realtime processes running under VxWorks,
7545 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7546 stub on the target system.
7548 New CPUs supported include the AMD 29000 and Intel 960.
7550 GDB now reads object files and symbol tables via a ``binary file''
7551 library, which allows a single copy of GDB to debug programs of multiple
7552 object file types such as a.out and coff.
7554 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7555 refcard.dvi and refcard.ps are available to format it).
7558 * Control-Variable user interface simplified
7560 All variables that control the operation of the debugger can be set
7561 by the ``set'' command, and displayed by the ``show'' command.
7563 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7564 ``Show prompt'' produces the response:
7565 Gdb's prompt is new-gdb=>.
7567 What follows are the NEW set commands. The command ``help set'' will
7568 print a complete list of old and new set commands. ``help set FOO''
7569 will give a longer description of the variable FOO. ``show'' will show
7570 all of the variable descriptions and their current settings.
7572 confirm on/off: Enables warning questions for operations that are
7573 hard to recover from, e.g. rerunning the program while
7574 it is already running. Default is ON.
7576 editing on/off: Enables EMACS style command line editing
7577 of input. Previous lines can be recalled with
7578 control-P, the current line can be edited with control-B,
7579 you can search for commands with control-R, etc.
7582 history filename NAME: NAME is where the gdb command history
7583 will be stored. The default is .gdb_history,
7584 or the value of the environment variable
7587 history size N: The size, in commands, of the command history. The
7588 default is 256, or the value of the environment variable
7591 history save on/off: If this value is set to ON, the history file will
7592 be saved after exiting gdb. If set to OFF, the
7593 file will not be saved. The default is OFF.
7595 history expansion on/off: If this value is set to ON, then csh-like
7596 history expansion will be performed on
7597 command line input. The default is OFF.
7599 radix N: Sets the default radix for input and output. It can be set
7600 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7601 in the current radix, so "set radix 10" is always a no-op.
7603 height N: This integer value is the number of lines on a page. Default
7604 is 24, the current `stty rows'' setting, or the ``li#''
7605 setting from the termcap entry matching the environment
7608 width N: This integer value is the number of characters on a line.
7609 Default is 80, the current `stty cols'' setting, or the ``co#''
7610 setting from the termcap entry matching the environment
7613 Note: ``set screensize'' is obsolete. Use ``set height'' and
7614 ``set width'' instead.
7616 print address on/off: Print memory addresses in various command displays,
7617 such as stack traces and structure values. Gdb looks
7618 more ``symbolic'' if you turn this off; it looks more
7619 ``machine level'' with it on. Default is ON.
7621 print array on/off: Prettyprint arrays. New convenient format! Default
7624 print demangle on/off: Print C++ symbols in "source" form if on,
7627 print asm-demangle on/off: Same, for assembler level printouts
7630 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7633 * Support for Epoch Environment.
7635 The epoch environment is a version of Emacs v18 with windowing. One
7636 new command, ``inspect'', is identical to ``print'', except that if you
7637 are running in the epoch environment, the value is printed in its own
7641 * Support for Shared Libraries
7643 GDB can now debug programs and core files that use SunOS shared libraries.
7644 Symbols from a shared library cannot be referenced
7645 before the shared library has been linked with the program (this
7646 happens after you type ``run'' and before the function main() is entered).
7647 At any time after this linking (including when examining core files
7648 from dynamically linked programs), gdb reads the symbols from each
7649 shared library when you type the ``sharedlibrary'' command.
7650 It can be abbreviated ``share''.
7652 sharedlibrary REGEXP: Load shared object library symbols for files
7653 matching a unix regular expression. No argument
7654 indicates to load symbols for all shared libraries.
7656 info sharedlibrary: Status of loaded shared libraries.
7661 A watchpoint stops execution of a program whenever the value of an
7662 expression changes. Checking for this slows down execution
7663 tremendously whenever you are in the scope of the expression, but is
7664 quite useful for catching tough ``bit-spreader'' or pointer misuse
7665 problems. Some machines such as the 386 have hardware for doing this
7666 more quickly, and future versions of gdb will use this hardware.
7668 watch EXP: Set a watchpoint (breakpoint) for an expression.
7670 info watchpoints: Information about your watchpoints.
7672 delete N: Deletes watchpoint number N (same as breakpoints).
7673 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7674 enable N: Re-enables watchpoint number N (same as breakpoints).
7677 * C++ multiple inheritance
7679 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7682 * C++ exception handling
7684 Gdb now supports limited C++ exception handling. Besides the existing
7685 ability to breakpoint on an exception handler, gdb can breakpoint on
7686 the raising of an exception (before the stack is peeled back to the
7689 catch FOO: If there is a FOO exception handler in the dynamic scope,
7690 set a breakpoint to catch exceptions which may be raised there.
7691 Multiple exceptions (``catch foo bar baz'') may be caught.
7693 info catch: Lists all exceptions which may be caught in the
7694 current stack frame.
7697 * Minor command changes
7699 The command ``call func (arg, arg, ...)'' now acts like the print
7700 command, except it does not print or save a value if the function's result
7701 is void. This is similar to dbx usage.
7703 The ``up'' and ``down'' commands now always print the frame they end up
7704 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7705 frames without printing.
7707 * New directory command
7709 'dir' now adds directories to the FRONT of the source search path.
7710 The path starts off empty. Source files that contain debug information
7711 about the directory in which they were compiled can be found even
7712 with an empty path; Sun CC and GCC include this information. If GDB can't
7713 find your source file in the current directory, type "dir .".
7715 * Configuring GDB for compilation
7717 For normal use, type ``./configure host''. See README or gdb.texinfo
7720 GDB now handles cross debugging. If you are remotely debugging between
7721 two different machines, type ``./configure host -target=targ''.
7722 Host is the machine where GDB will run; targ is the machine
7723 where the program that you are debugging will run.