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.
63 ** The gdb.Value type has a new method 'format_string' which returns a
64 string representing the value. The formatting is controlled by the
65 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
66 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
67 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
69 ** gdb.Type has a new property 'objfile' which returns the objfile the
72 ** The frame information printed by the python frame filtering code
73 is now consistent with what the 'backtrace' command prints when
74 there are no filters, or when the 'backtrace' '-no-filters' option
77 ** The new function gdb.lookup_static_symbol can be used to look up
78 symbols with static linkage.
80 ** The new function gdb.lookup_static_symbols can be used to look up
81 all static symbols with static linkage.
83 ** gdb.Objfile has new methods 'lookup_global_symbol' and
84 'lookup_static_symbol' to lookup a symbol from this objfile only.
86 ** gdb.Block now supports the dictionary syntax for accessing symbols in
87 this block (e.g. block['local_variable']).
91 | [COMMAND] | SHELL_COMMAND
92 | -d DELIM COMMAND DELIM SHELL_COMMAND
93 pipe [COMMAND] | SHELL_COMMAND
94 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
95 Executes COMMAND and sends its output to SHELL_COMMAND.
96 With no COMMAND, repeat the last executed command
97 and send its output to SHELL_COMMAND.
99 with SETTING [VALUE] [-- COMMAND]
100 w SETTING [VALUE] [-- COMMAND]
101 Temporarily set SETTING, run COMMAND, and restore SETTING.
102 Usage: with SETTING -- COMMAND
103 With no COMMAND, repeats the last executed command.
104 SETTING is any GDB setting you can change with the "set"
105 subcommands. For example, 'with language c -- print someobj'
106 temporarily switches to the C language in order to print someobj.
107 Settings can be combined: 'w lang c -- w print elements unlimited --
108 usercmd' switches to the C language and runs usercmd with no limit
109 of array elements to print.
111 maint with SETTING [VALUE] [-- COMMAND]
112 Like "with", but works with "maintenance set" settings.
114 set may-call-functions [on|off]
115 show may-call-functions
116 This controls whether GDB will attempt to call functions in
117 the program, such as with expressions in the print command. It
118 defaults to on. Calling functions in the program being debugged
119 can have undesired side effects. It is now possible to forbid
120 such function calls. If function calls are forbidden, GDB will throw
121 an error when a command (such as print expression) calls a function
124 set print finish [on|off]
126 This controls whether the `finish' command will display the value
127 that is returned by the current function. When `off', the value is
128 still entered into the value history, but it is not printed. The
133 Allows deeply nested structures to be simplified when printing by
134 replacing deeply nested parts (beyond the max-depth) with ellipses.
135 The default max-depth is 20, but this can be set to unlimited to get
136 the old behavior back.
138 set logging debugredirect [on|off]
139 By default, GDB debug output will go to both the terminal and the logfile.
140 Set if you want debug output to go only to the log file.
142 set style title foreground COLOR
143 set style title background COLOR
144 set style title intensity VALUE
145 Control the styling of titles.
147 set style highlight foreground COLOR
148 set style highlight background COLOR
149 set style highlight intensity VALUE
150 Control the styling of highlightings.
152 maint set worker-threads
153 maint show worker-threads
154 Control the number of worker threads that can be used by GDB. The
155 default is "unlimited", which lets GDB choose a number that is
156 reasonable. Currently worker threads are only used when demangling
157 the names of linker symbols.
159 maint set test-settings KIND
160 maint show test-settings KIND
161 A set of commands used by the testsuite for exercising the settings
164 maint set tui-resize-message [on|off]
165 maint show tui-resize-message
166 Control whether GDB prints a message each time the terminal is
167 resized when in TUI mode. This is primarily useful for testing the
170 set print frame-info [short-location|location|location-and-address
171 |source-and-location|source-line|auto]
172 show print frame-info
173 This controls what frame information is printed by the commands printing
174 a frame. This setting will e.g. influence the behaviour of 'backtrace',
175 'frame', 'stepi'. The python frame filtering also respect this setting.
176 The 'backtrace' '-frame-info' option can override this global setting.
178 info modules [-q] [REGEXP]
179 Return a list of Fortran modules matching REGEXP, or all modules if
182 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
183 Return a list of functions within all modules, grouped by module.
184 The list of functions can be restricted with the optional regular
185 expressions. MODULE_REGEXP matches against the module name,
186 TYPE_REGEXP matches against the function type signature, and REGEXP
187 matches against the function name.
189 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
190 Return a list of variables within all modules, grouped by module.
191 The list of variables can be restricted with the optional regular
192 expressions. MODULE_REGEXP matches against the module name,
193 TYPE_REGEXP matches against the variable type, and REGEXP matches
194 against the variable name.
196 set debug remote-packet-max-chars
197 show debug remote-packet-max-chars
198 Controls the number of characters to output in a remote packet when using
200 The default is 512 bytes.
205 The "help" command uses the title style to enhance the
206 readibility of its output by styling the classes and
210 Similarly to "help", the "apropos" command also uses the
211 title style for the command names. "apropos" accepts now
212 a flag "-v" (verbose) to show the full documentation
213 of matching commands and to use the highlight style to mark
214 the documentation parts matching REGEXP.
218 The GDB printf and eval commands can now print C-style and Ada-style
219 string convenience variables without calling functions in the program.
220 This allows to do formatted printing of strings without having
221 a running inferior, or when debugging a core dump.
223 info sources [-dirname | -basename] [--] [REGEXP]
224 This command has now optional arguments to only print the files
225 whose names match REGEXP. The arguments -dirname and -basename
226 allow to restrict matching respectively to the dirname and basename
230 The "show style" and its subcommands are now styling
231 a style name in their output using its own style, to help
232 the user visualize the different styles.
234 set print frame-arguments
235 The new value 'presence' indicates to only indicate the presence of
236 arguments using ..., instead of printing argument names and values.
238 set print raw-frame-arguments
239 show print raw-frame-arguments
241 These commands replace the similarly-named "set/show print raw
242 frame-arguments" commands (now with a dash instead of a space). The
243 old commands are now deprecated and may be removed in a future
246 maint test-options require-delimiter
247 maint test-options unknown-is-error
248 maint test-options unknown-is-operand
249 maint show test-options-completion-result
250 Commands used by the testsuite to validate the command options
253 focus, winheight, +, -, >, <
254 These commands are now case-sensitive.
256 * New command options, command completion
258 GDB now has a standard infrastructure to support dash-style command
259 options ('-OPT'). One benefit is that commands that use it can
260 easily support completion of command line arguments. Try "CMD
261 -[TAB]" or "help CMD" to find options supported by a command. Over
262 time, we intend to migrate most commands to this infrastructure. A
263 number of commands got support for new command options in this
266 ** The "print" and "compile print" commands now support a number of
267 options that allow overriding relevant global print settings as
268 set by "set print" subcommands:
272 -array-indexes [on|off]
273 -elements NUMBER|unlimited
277 -repeats NUMBER|unlimited
278 -static-members [on|off]
283 Note that because the "print"/"compile print" commands accept
284 arbitrary expressions which may look like options (including
285 abbreviations), if you specify any command option, then you must
286 use a double dash ("--") to mark the end of argument processing.
288 ** The "backtrace" command now supports a number of options that
289 allow overriding relevant global print settings as set by "set
290 backtrace" and "set print" subcommands:
292 -entry-values no|only|preferred|if-needed|both|compact|default
293 -frame-arguments all|scalars|none
294 -raw-frame-arguments [on|off]
295 -frame-info auto|source-line|location|source-and-location
296 |location-and-address|short-location
300 In addition, the full/no-filters/hide qualifiers are now also
301 exposed as command options too:
307 ** The "frame apply", "tfaas" and "faas" commands similarly now
308 support the following options:
313 ** The new "info sources" options -dirname and -basename options
314 are using the standard '-OPT' infrastructure.
316 All options above can also be abbreviated. The argument of boolean
317 (on/off) options can be 0/1 too, and also the argument is assumed
318 "on" if omitted. This allows writing compact command invocations,
321 (gdb) p -r -p -o 0 -- *myptr
323 The above is equivalent to:
325 (gdb) print -raw -pretty -object off -- *myptr
327 ** The "info types" command now supports the '-q' flag to disable
328 printing of some header information in a similar fashion to "info
329 variables" and "info functions".
331 ** The "info variables", "info functions", and "whereis" commands
332 now take a '-n' flag that excludes non-debug symbols (symbols
333 from the symbol table, not from the debug info such as DWARF)
336 * Completion improvements
338 ** GDB can now complete the options of the "thread apply all" and
339 "taas" commands, and their "-ascending" option can now be
342 ** GDB can now complete the options of the "info threads", "info
343 functions", "info variables", "info locals", and "info args"
346 ** GDB can now complete the options of the "compile file" and
347 "compile code" commands. The "compile file" command now
348 completes on filenames.
350 ** GDB can now complete the backtrace command's
351 "full/no-filters/hide" qualifiers.
353 * In settings, you can now abbreviate "unlimited".
355 E.g., "set print elements u" is now equivalent to "set print
361 This lists all the possible completions for the rest of the line, if it
362 were to be given as a command itself. This is intended for use by MI
363 frontends in cases when separate CLI and MI channels cannot be used.
365 -catch-throw, -catch-rethrow, and -catch-catch
366 These can be used to catch C++ exceptions in a similar fashion to
367 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
371 ** The default version of the MI interpreter is now 3 (-i=mi3).
373 ** The output of information about multi-location breakpoints (which is
374 syntactically incorrect in MI 2) has changed in MI 3. This affects
375 the following commands and events:
379 - =breakpoint-created
380 - =breakpoint-modified
382 The -fix-multi-location-breakpoint-output command can be used to enable
383 this behavior with previous MI versions.
385 ** Backtraces and frames include a new optional field addr_flags which is
386 given after the addr field. On AArch64 this contains PAC if the address
387 has been masked in the frame. On all other targets the field is not
392 The testsuite now creates the files gdb.cmd (containing the arguments
393 used to launch GDB) and gdb.in (containing all the commands sent to
394 GDB) in the output directory for each test script. Multiple invocations
395 are appended with .1, .2, .3 etc.
397 * Building GDB and GDBserver now requires GNU make >= 3.82.
399 Using another implementation of the make program or an earlier version of
400 GNU make to build GDB or GDBserver is not supported.
402 * Building GDB now requires GNU readline >= 7.0.
404 GDB now bundles GNU readline 8.0, but if you choose to use
405 --with-system-readline, only readline >= 7.0 can be used.
407 * The TUI SingleKey keymap is now named "SingleKey". This can be used
408 from .inputrc to bind keys in this keymap. This feature is only
409 available when gdb is built against GNU readline 8.0 or later.
411 * Removed targets and native configurations
413 GDB no longer supports debugging the Cell Broadband Engine. This includes
414 both debugging standalone Cell/B.E. SPU applications and integrated debugging
415 of Cell/B.E. applications that use both the PPU and SPU architectures.
421 * Removed targets and native configurations
423 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
426 *** Changes in GDB 8.3
428 * GDB and GDBserver now support access to additional registers on
429 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
432 * GDB now has experimental support for the compilation and injection of
433 C++ source code into the inferior. This beta release does not include
434 support for several language features, such as templates, constructors,
437 This feature requires GCC 7.1 or higher built with libcp1.so
440 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
441 can be passed using the '[ADDRESS]:PORT' notation, or the regular
442 'ADDRESS:PORT' method.
444 * DWARF index cache: GDB can now automatically save indices of DWARF
445 symbols on disk to speed up further loading of the same binaries.
447 * Ada task switching is now supported on aarch64-elf targets when
448 debugging a program using the Ravenscar Profile. For more information,
449 see the "Tasking Support when using the Ravenscar Profile" section
450 in the GDB user manual.
452 * GDB in batch mode now exits with status 1 if the last command to be
455 * The RISC-V target now supports target descriptions.
457 * System call catchpoints now support system call aliases on FreeBSD.
458 When the ABI of a system call changes in FreeBSD, this is
459 implemented by leaving a compatibility system call using the old ABI
460 at the existing number and allocating a new system call number for
461 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
462 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
463 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
464 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
465 so that a system call catchpoint for the 'kevent' system call will
466 catch invocations of both the 'kevent' and 'freebsd11_kevent'
467 binaries. This ensures that 'kevent' system calls are caught for
468 binaries using either the old or new ABIs.
470 * Terminal styling is now available for the CLI and the TUI. GNU
471 Source Highlight can additionally be used to provide styling of
472 source code snippets. See the "set style" commands, below, for more
475 * Removed support for old demangling styles arm, edg, gnu, hp and
480 set debug compile-cplus-types
481 show debug compile-cplus-types
482 Control the display of debug output about type conversion in the
483 C++ compile feature. Commands have no effect while compiliong
488 Control whether debug output about files/functions skipping is
491 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
492 Apply a command to some frames.
493 FLAG arguments allow to control what output to produce and how to handle
494 errors raised when applying COMMAND to a frame.
497 Apply a command to all threads (ignoring errors and empty output).
498 Shortcut for 'thread apply all -s COMMAND'.
501 Apply a command to all frames (ignoring errors and empty output).
502 Shortcut for 'frame apply all -s COMMAND'.
505 Apply a command to all frames of all threads (ignoring errors and empty
507 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
509 maint set dwarf unwinders (on|off)
510 maint show dwarf unwinders
511 Control whether DWARF unwinders can be used.
514 Display a list of open files for a process.
518 Changes to the "frame", "select-frame", and "info frame" CLI commands.
519 These commands all now take a frame specification which
520 is either a frame level, or one of the keywords 'level', 'address',
521 'function', or 'view' followed by a parameter. Selecting a frame by
522 address, or viewing a frame outside the current backtrace now
523 requires the use of a keyword. Selecting a frame by level is
524 unchanged. The MI comment "-stack-select-frame" is unchanged.
526 target remote FILENAME
527 target extended-remote FILENAME
528 If FILENAME is a Unix domain socket, GDB will attempt to connect
529 to this socket instead of opening FILENAME as a character device.
531 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
532 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
533 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
534 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
535 These commands can now print only the searched entities
536 matching the provided regexp(s), giving a condition
537 on the entity names or entity types. The flag -q disables
538 printing headers or informations messages.
544 These commands now determine the syntax for the shown entities
545 according to the language chosen by `set language'. In particular,
546 `set language auto' means to automatically choose the language of
549 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
550 The 'thread apply' command accepts new FLAG arguments.
551 FLAG arguments allow to control what output to produce and how to handle
552 errors raised when applying COMMAND to a thread.
554 set tui tab-width NCHARS
555 show tui tab-width NCHARS
556 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
558 set style enabled [on|off]
560 Enable or disable terminal styling. Styling is enabled by default
561 on most hosts, but disabled by default when in batch mode.
563 set style sources [on|off]
565 Enable or disable source code styling. Source code styling is
566 enabled by default, but only takes effect if styling in general is
567 enabled, and if GDB was linked with GNU Source Highlight.
569 set style filename foreground COLOR
570 set style filename background COLOR
571 set style filename intensity VALUE
572 Control the styling of file names.
574 set style function foreground COLOR
575 set style function background COLOR
576 set style function intensity VALUE
577 Control the styling of function names.
579 set style variable foreground COLOR
580 set style variable background COLOR
581 set style variable intensity VALUE
582 Control the styling of variable names.
584 set style address foreground COLOR
585 set style address background COLOR
586 set style address intensity VALUE
587 Control the styling of addresses.
591 ** The '-data-disassemble' MI command now accepts an '-a' option to
592 disassemble the whole function surrounding the given program
593 counter value or function name. Support for this feature can be
594 verified by using the "-list-features" command, which should
595 contain "data-disassemble-a-option".
597 ** Command responses and notifications that include a frame now include
598 the frame's architecture in a new "arch" attribute.
600 * New native configurations
602 GNU/Linux/RISC-V riscv*-*-linux*
603 FreeBSD/riscv riscv*-*-freebsd*
607 GNU/Linux/RISC-V riscv*-*-linux*
609 CSKY GNU/LINUX csky*-*-linux
610 FreeBSD/riscv riscv*-*-freebsd*
612 GNU/Linux/OpenRISC or1k*-*-linux*
616 GDB no longer supports native debugging on versions of MS-Windows
621 ** GDB no longer supports Python versions less than 2.6.
623 ** The gdb.Inferior type has a new 'progspace' property, which is the program
624 space associated to that inferior.
626 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
627 of objfiles associated to that program space.
629 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
630 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
633 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
634 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
635 correct and did not work properly.
637 ** The gdb.Value type has a new constructor, which is used to construct a
638 gdb.Value from a Python buffer object and a gdb.Type.
644 Enable or disable the undefined behavior sanitizer. This is
645 disabled by default, but passing --enable-ubsan=yes or
646 --enable-ubsan=auto to configure will enable it. Enabling this can
647 cause a performance penalty. The undefined behavior sanitizer was
648 first introduced in GCC 4.9.
650 *** Changes in GDB 8.2
652 * The 'set disassembler-options' command now supports specifying options
655 * The 'symbol-file' command now accepts an '-o' option to add a relative
656 offset to all sections.
658 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
659 a relative offset to all sections, but it allows to override the load
660 address of individual sections using '-s'.
662 * The 'add-symbol-file' command no longer requires the second argument
663 (address of the text section).
665 * The endianness used with the 'set endian auto' mode in the absence of
666 an executable selected for debugging is now the last endianness chosen
667 either by one of the 'set endian big' and 'set endian little' commands
668 or by inferring from the last executable used, rather than the startup
671 * The pager now allows a "c" response, meaning to disable the pager
672 for the rest of the current command.
674 * The commands 'info variables/functions/types' now show the source line
675 numbers of symbol definitions when available.
677 * 'info proc' now works on running processes on FreeBSD systems and core
678 files created on FreeBSD systems.
680 * C expressions can now use _Alignof, and C++ expressions can now use
683 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
684 the vector length while the process is running.
690 Control display of debugging info regarding the FreeBSD native target.
692 set|show varsize-limit
693 This new setting allows the user to control the maximum size of Ada
694 objects being printed when those objects have a variable type,
695 instead of that maximum size being hardcoded to 65536 bytes.
697 set|show record btrace cpu
698 Controls the processor to be used for enabling errata workarounds for
701 maint check libthread-db
702 Run integrity checks on the current inferior's thread debugging
705 maint set check-libthread-db (on|off)
706 maint show check-libthread-db
707 Control whether to run integrity checks on inferior specific thread
708 debugging libraries as they are loaded. The default is not to
713 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
715 ** The commands attached to a breakpoint can be set by assigning to
716 the breakpoint's "commands" field.
718 ** gdb.execute can now execute multi-line gdb commands.
720 ** The new functions gdb.convenience_variable and
721 gdb.set_convenience_variable can be used to get and set the value
722 of convenience variables.
724 ** A gdb.Parameter will no longer print the "set" help text on an
725 ordinary "set"; instead by default a "set" will be silent unless
726 the get_set_string method returns a non-empty string.
730 RiscV ELF riscv*-*-elf
732 * Removed targets and native configurations
734 m88k running OpenBSD m88*-*-openbsd*
735 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
736 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
737 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
739 * Aarch64/Linux hardware watchpoints improvements
741 Hardware watchpoints on unaligned addresses are now properly
742 supported when running Linux kernel 4.10 or higher: read and access
743 watchpoints are no longer spuriously missed, and all watchpoints
744 lengths between 1 and 8 bytes are supported. On older kernels,
745 watchpoints set on unaligned addresses are no longer missed, with
746 the tradeoff that there is a possibility of false hits being
751 --enable-codesign=CERT
752 This can be used to invoke "codesign -s CERT" after building gdb.
753 This option is useful on macOS, where code signing is required for
754 gdb to work properly.
756 --disable-gdbcli has been removed
757 This is now silently accepted, but does nothing.
759 *** Changes in GDB 8.1
761 * GDB now supports dynamically creating arbitrary register groups specified
762 in XML target descriptions. This allows for finer grain grouping of
763 registers on systems with a large amount of registers.
765 * The 'ptype' command now accepts a '/o' flag, which prints the
766 offsets and sizes of fields in a struct, like the pahole(1) tool.
768 * New "--readnever" command line option instructs GDB to not read each
769 symbol file's symbolic debug information. This makes startup faster
770 but at the expense of not being able to perform symbolic debugging.
771 This option is intended for use cases where symbolic debugging will
772 not be used, e.g., when you only need to dump the debuggee's core.
774 * GDB now uses the GNU MPFR library, if available, to emulate target
775 floating-point arithmetic during expression evaluation when the target
776 uses different floating-point formats than the host. At least version
777 3.1 of GNU MPFR is required.
779 * GDB now supports access to the guarded-storage-control registers and the
780 software-based guarded-storage broadcast control registers on IBM z14.
782 * On Unix systems, GDB now supports transmitting environment variables
783 that are to be set or unset to GDBserver. These variables will
784 affect the environment to be passed to the remote inferior.
786 To inform GDB of environment variables that are to be transmitted to
787 GDBserver, use the "set environment" command. Only user set
788 environment variables are sent to GDBserver.
790 To inform GDB of environment variables that are to be unset before
791 the remote inferior is started by the GDBserver, use the "unset
792 environment" command.
794 * Completion improvements
796 ** GDB can now complete function parameters in linespecs and
797 explicit locations without quoting. When setting breakpoints,
798 quoting around functions names to help with TAB-completion is
799 generally no longer necessary. For example, this now completes
802 (gdb) b function(in[TAB]
803 (gdb) b function(int)
805 Related, GDB is no longer confused with completing functions in
806 C++ anonymous namespaces:
809 (gdb) b (anonymous namespace)::[TAB][TAB]
810 (anonymous namespace)::a_function()
811 (anonymous namespace)::b_function()
813 ** GDB now has much improved linespec and explicit locations TAB
814 completion support, that better understands what you're
815 completing and offers better suggestions. For example, GDB no
816 longer offers data symbols as possible completions when you're
817 setting a breakpoint.
819 ** GDB now TAB-completes label symbol names.
821 ** The "complete" command now mimics TAB completion accurately.
823 * New command line options (gcore)
826 Dump all memory mappings.
828 * Breakpoints on C++ functions are now set on all scopes by default
830 By default, breakpoints on functions/methods are now interpreted as
831 specifying all functions with the given name ignoring missing
832 leading scopes (namespaces and classes).
834 For example, assuming a C++ program with symbols named:
839 both commands "break func()" and "break B::func()" set a breakpoint
842 You can use the new flag "-qualified" to override this. This makes
843 GDB interpret the specified function name as a complete
844 fully-qualified name instead. For example, using the same C++
845 program, the "break -q B::func" command sets a breakpoint on
846 "B::func", only. A parameter has been added to the Python
847 gdb.Breakpoint constructor to achieve the same result when creating
848 a breakpoint from Python.
850 * Breakpoints on functions marked with C++ ABI tags
852 GDB can now set breakpoints on functions marked with C++ ABI tags
853 (e.g., [abi:cxx11]). See here for a description of ABI tags:
854 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
856 Functions with a C++11 abi tag are demangled/displayed like this:
858 function[abi:cxx11](int)
861 You can now set a breakpoint on such functions simply as if they had
864 (gdb) b function(int)
866 Or if you need to disambiguate between tags, like:
868 (gdb) b function[abi:other_tag](int)
870 Tab completion was adjusted accordingly as well.
874 ** New events gdb.new_inferior, gdb.inferior_deleted, and
875 gdb.new_thread are emitted. See the manual for further
876 description of these.
878 ** A new function, "gdb.rbreak" has been added to the Python API.
879 This function allows the setting of a large number of breakpoints
880 via a regex pattern in Python. See the manual for further details.
882 ** Python breakpoints can now accept explicit locations. See the
883 manual for a further description of this feature.
886 * New features in the GDB remote stub, GDBserver
888 ** GDBserver is now able to start inferior processes with a
889 specified initial working directory.
891 The user can set the desired working directory to be used from
892 GDB using the new "set cwd" command.
894 ** New "--selftest" command line option runs some GDBserver self
895 tests. These self tests are disabled in releases.
897 ** On Unix systems, GDBserver now does globbing expansion and variable
898 substitution in inferior command line arguments.
900 This is done by starting inferiors using a shell, like GDB does.
901 See "set startup-with-shell" in the user manual for how to disable
902 this from GDB when using "target extended-remote". When using
903 "target remote", you can disable the startup with shell by using the
904 new "--no-startup-with-shell" GDBserver command line option.
906 ** On Unix systems, GDBserver now supports receiving environment
907 variables that are to be set or unset from GDB. These variables
908 will affect the environment to be passed to the inferior.
910 * When catching an Ada exception raised with a message, GDB now prints
911 the message in the catchpoint hit notification. In GDB/MI mode, that
912 information is provided as an extra field named "exception-message"
913 in the *stopped notification.
915 * Trait objects can now be inspected When debugging Rust code. This
916 requires compiler support which will appear in Rust 1.24.
920 QEnvironmentHexEncoded
921 Inform GDBserver of an environment variable that is to be passed to
922 the inferior when starting it.
925 Inform GDBserver of an environment variable that is to be unset
926 before starting the remote inferior.
929 Inform GDBserver that the environment should be reset (i.e.,
930 user-set environment variables should be unset).
933 Indicates whether the inferior must be started with a shell or not.
936 Tell GDBserver that the inferior to be started should use a specific
939 * The "maintenance print c-tdesc" command now takes an optional
940 argument which is the file name of XML target description.
942 * The "maintenance selftest" command now takes an optional argument to
943 filter the tests to be run.
945 * The "enable", and "disable" commands now accept a range of
946 breakpoint locations, e.g. "enable 1.3-5".
951 Set and show the current working directory for the inferior.
954 Set and show compilation command used for compiling and injecting code
955 with the 'compile' commands.
957 set debug separate-debug-file
958 show debug separate-debug-file
959 Control the display of debug output about separate debug file search.
961 set dump-excluded-mappings
962 show dump-excluded-mappings
963 Control whether mappings marked with the VM_DONTDUMP flag should be
964 dumped when generating a core file.
967 List the registered selftests.
970 Start the debugged program stopping at the first instruction.
973 Control display of debugging messages related to OpenRISC targets.
975 set|show print type nested-type-limit
976 Set and show the limit of nesting level for nested types that the
977 type printer will show.
979 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
982 * Safer/improved support for debugging with no debug info
984 GDB no longer assumes functions with no debug information return
987 This means that GDB now refuses to call such functions unless you
988 tell it the function's type, by either casting the call to the
989 declared return type, or by casting the function to a function
990 pointer of the right type, and calling that:
992 (gdb) p getenv ("PATH")
993 'getenv' has unknown return type; cast the call to its declared return type
994 (gdb) p (char *) getenv ("PATH")
995 $1 = 0x7fffffffe "/usr/local/bin:/"...
996 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
997 $2 = 0x7fffffffe "/usr/local/bin:/"...
999 Similarly, GDB no longer assumes that global variables with no debug
1000 info have type 'int', and refuses to print the variable's value
1001 unless you tell it the variable's type:
1004 'var' has unknown type; cast it to its declared type
1008 * New native configurations
1010 FreeBSD/aarch64 aarch64*-*-freebsd*
1011 FreeBSD/arm arm*-*-freebsd*
1015 FreeBSD/aarch64 aarch64*-*-freebsd*
1016 FreeBSD/arm arm*-*-freebsd*
1017 OpenRISC ELF or1k*-*-elf
1019 * Removed targets and native configurations
1021 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1023 *** Changes in GDB 8.0
1025 * GDB now supports access to the PKU register on GNU/Linux. The register is
1026 added by the Memory Protection Keys for Userspace feature which will be
1027 available in future Intel CPUs.
1029 * GDB now supports C++11 rvalue references.
1033 ** New functions to start, stop and access a running btrace recording.
1034 ** Rvalue references are now supported in gdb.Type.
1036 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1039 * Building GDB and GDBserver now requires a C++11 compiler.
1041 For example, GCC 4.8 or later.
1043 It is no longer possible to build GDB or GDBserver with a C
1044 compiler. The --disable-build-with-cxx configure option has been
1047 * Building GDB and GDBserver now requires GNU make >= 3.81.
1049 It is no longer supported to build GDB or GDBserver with another
1050 implementation of the make program or an earlier version of GNU make.
1052 * Native debugging on MS-Windows supports command-line redirection
1054 Command-line arguments used for starting programs on MS-Windows can
1055 now include redirection symbols supported by native Windows shells,
1056 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1057 as "run", "start", and "set args", as well as the corresponding MI
1060 * Support for thread names on MS-Windows.
1062 GDB now catches and handles the special exception that programs
1063 running on MS-Windows use to assign names to threads in the
1066 * Support for Java programs compiled with gcj has been removed.
1068 * User commands now accept an unlimited number of arguments.
1069 Previously, only up to 10 was accepted.
1071 * The "eval" command now expands user-defined command arguments.
1073 This makes it easier to process a variable number of arguments:
1078 eval "print $arg%d", $i
1083 * Target descriptions can now describe registers for sparc32 and sparc64.
1085 * GDB now supports DWARF version 5 (debug information format).
1086 Its .debug_names index is not yet supported.
1088 * New native configurations
1090 FreeBSD/mips mips*-*-freebsd
1094 Synopsys ARC arc*-*-elf32
1095 FreeBSD/mips mips*-*-freebsd
1097 * Removed targets and native configurations
1099 Alpha running FreeBSD alpha*-*-freebsd*
1100 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1105 Erases all the flash memory regions reported by the target.
1107 maint print arc arc-instruction address
1108 Print internal disassembler information about instruction at a given address.
1112 set disassembler-options
1113 show disassembler-options
1114 Controls the passing of target specific information to the disassembler.
1115 If it is necessary to specify more than one disassembler option then
1116 multiple options can be placed together into a comma separated list.
1117 The default value is the empty string. Currently, the only supported
1118 targets are ARM, PowerPC and S/390.
1123 Erases all the flash memory regions reported by the target. This is
1124 equivalent to the CLI command flash-erase.
1126 -file-list-shared-libraries
1127 List the shared libraries in the program. This is
1128 equivalent to the CLI command "info shared".
1131 Catchpoints stopping the program when Ada exceptions are
1132 handled. This is equivalent to the CLI command "catch handlers".
1134 *** Changes in GDB 7.12
1136 * GDB and GDBserver now build with a C++ compiler by default.
1138 The --enable-build-with-cxx configure option is now enabled by
1139 default. One must now explicitly configure with
1140 --disable-build-with-cxx in order to build with a C compiler. This
1141 option will be removed in a future release.
1143 * GDBserver now supports recording btrace without maintaining an active
1146 * GDB now supports a negative repeat count in the 'x' command to examine
1147 memory backward from the given address. For example:
1150 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1151 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1152 (gdb) x/-5i 0x0000000000400580
1153 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1154 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1155 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1156 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1157 0x40057b <main(int, char**)+25>:
1158 callq 0x400536 <Func1(int, char const*)>
1160 * Fortran: Support structures with fields of dynamic types and
1161 arrays of dynamic types.
1163 * The symbol dumping maintenance commands have new syntax.
1164 maint print symbols [-pc address] [--] [filename]
1165 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1166 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1167 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1168 maint print msymbols [-objfile objfile] [--] [filename]
1170 * GDB now supports multibit bitfields and enums in target register
1173 * New Python-based convenience function $_as_string(val), which returns
1174 the textual representation of a value. This function is especially
1175 useful to obtain the text label of an enum value.
1177 * Intel MPX bound violation handling.
1179 Segmentation faults caused by a Intel MPX boundary violation
1180 now display the kind of violation (upper or lower), the memory
1181 address accessed and the memory bounds, along with the usual
1182 signal received and code location.
1186 Program received signal SIGSEGV, Segmentation fault
1187 Upper bound violation while accessing address 0x7fffffffc3b3
1188 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1189 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1191 * Rust language support.
1192 GDB now supports debugging programs written in the Rust programming
1193 language. See https://www.rust-lang.org/ for more information about
1196 * Support for running interpreters on specified input/output devices
1198 GDB now supports a new mechanism that allows frontends to provide
1199 fully featured GDB console views, as a better alternative to
1200 building such views on top of the "-interpreter-exec console"
1201 command. See the new "new-ui" command below. With that command,
1202 frontends can now start GDB in the traditional command-line mode
1203 running in an embedded terminal emulator widget, and create a
1204 separate MI interpreter running on a specified i/o device. In this
1205 way, GDB handles line editing, history, tab completion, etc. in the
1206 console all by itself, and the GUI uses the separate MI interpreter
1207 for its own control and synchronization, invisible to the command
1210 * The "catch syscall" command catches groups of related syscalls.
1212 The "catch syscall" command now supports catching a group of related
1213 syscalls using the 'group:' or 'g:' prefix.
1218 skip -gfile file-glob-pattern
1219 skip -function function
1220 skip -rfunction regular-expression
1221 A generalized form of the skip command, with new support for
1222 glob-style file names and regular expressions for function names.
1223 Additionally, a file spec and a function spec may now be combined.
1225 maint info line-table REGEXP
1226 Display the contents of GDB's internal line table data struture.
1229 Run any GDB unit tests that were compiled in.
1232 Start a new user interface instance running INTERP as interpreter,
1233 using the TTY file for input/output.
1237 ** gdb.Breakpoint objects have a new attribute "pending", which
1238 indicates whether the breakpoint is pending.
1239 ** Three new breakpoint-related events have been added:
1240 gdb.breakpoint_created, gdb.breakpoint_modified, and
1241 gdb.breakpoint_deleted.
1243 signal-event EVENTID
1244 Signal ("set") the given MS-Windows event object. This is used in
1245 conjunction with the Windows JIT debugging (AeDebug) support, where
1246 the OS suspends a crashing process until a debugger can attach to
1247 it. Resuming the crashing process, in order to debug it, is done by
1248 signalling an event.
1250 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1251 was added in GDBserver, including JIT compiling fast tracepoint's
1252 conditional expression bytecode into native code.
1254 * Support for various remote target protocols and ROM monitors has
1257 target m32rsdi Remote M32R debugging over SDI
1258 target mips MIPS remote debugging protocol
1259 target pmon PMON ROM monitor
1260 target ddb NEC's DDB variant of PMON for Vr4300
1261 target rockhopper NEC RockHopper variant of PMON
1262 target lsi LSI variant of PMO
1264 * Support for tracepoints and fast tracepoints on powerpc-linux,
1265 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1266 including JIT compiling fast tracepoint's conditional expression
1267 bytecode into native code.
1269 * MI async record =record-started now includes the method and format used for
1270 recording. For example:
1272 =record-started,thread-group="i1",method="btrace",format="bts"
1274 * MI async record =thread-selected now includes the frame field. For example:
1276 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1280 Andes NDS32 nds32*-*-elf
1282 *** Changes in GDB 7.11
1284 * GDB now supports debugging kernel-based threads on FreeBSD.
1286 * Per-inferior thread numbers
1288 Thread numbers are now per inferior instead of global. If you're
1289 debugging multiple inferiors, GDB displays thread IDs using a
1290 qualified INF_NUM.THR_NUM form. For example:
1294 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1295 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1296 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1297 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1299 As consequence, thread numbers as visible in the $_thread
1300 convenience variable and in Python's InferiorThread.num attribute
1301 are no longer unique between inferiors.
1303 GDB now maintains a second thread ID per thread, referred to as the
1304 global thread ID, which is the new equivalent of thread numbers in
1305 previous releases. See also $_gthread below.
1307 For backwards compatibility, MI's thread IDs always refer to global
1310 * Commands that accept thread IDs now accept the qualified
1311 INF_NUM.THR_NUM form as well. For example:
1314 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1317 * In commands that accept a list of thread IDs, you can now refer to
1318 all threads of an inferior using a star wildcard. GDB accepts
1319 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1320 refer to all threads of the current inferior. For example, "info
1323 * You can use "info threads -gid" to display the global thread ID of
1326 * The new convenience variable $_gthread holds the global number of
1329 * The new convenience variable $_inferior holds the number of the
1332 * GDB now displays the ID and name of the thread that hit a breakpoint
1333 or received a signal, if your program is multi-threaded. For
1336 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1337 Thread 1 "main" received signal SIGINT, Interrupt.
1339 * Record btrace now supports non-stop mode.
1341 * Support for tracepoints on aarch64-linux was added in GDBserver.
1343 * The 'record instruction-history' command now indicates speculative execution
1344 when using the Intel Processor Trace recording format.
1346 * GDB now allows users to specify explicit locations, bypassing
1347 the linespec parser. This feature is also available to GDB/MI
1350 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1351 GDB now is able to debug both AArch64 applications and ARM applications
1354 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1355 including JIT compiling fast tracepoint's conditional expression bytecode
1358 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1360 * "info threads", "info inferiors", "info display", "info checkpoints"
1361 and "maint info program-spaces" now list the corresponding items in
1362 ascending ID order, for consistency with all other "info" commands.
1364 * In Ada, the overloads selection menu has been enhanced to display the
1365 parameter types and the return types for the matching overloaded subprograms.
1369 maint set target-non-stop (on|off|auto)
1370 maint show target-non-stop
1371 Control whether GDB targets always operate in non-stop mode even if
1372 "set non-stop" is "off". The default is "auto", meaning non-stop
1373 mode is enabled if supported by the target.
1375 maint set bfd-sharing
1376 maint show bfd-sharing
1377 Control the reuse of bfd objects.
1380 show debug bfd-cache
1381 Control display of debugging info regarding bfd caching.
1385 Control display of debugging info regarding FreeBSD threads.
1387 set remote multiprocess-extensions-packet
1388 show remote multiprocess-extensions-packet
1389 Set/show the use of the remote protocol multiprocess extensions.
1391 set remote thread-events
1392 show remote thread-events
1393 Set/show the use of thread create/exit events.
1395 set ada print-signatures on|off
1396 show ada print-signatures"
1397 Control whether parameter types and return types are displayed in overloads
1398 selection menus. It is activaled (@code{on}) by default.
1402 Controls the maximum size of memory, in bytes, that GDB will
1403 allocate for value contents. Prevents incorrect programs from
1404 causing GDB to allocate overly large buffers. Default is 64k.
1406 * The "disassemble" command accepts a new modifier: /s.
1407 It prints mixed source+disassembly like /m with two differences:
1408 - disassembled instructions are now printed in program order, and
1409 - and source for all relevant files is now printed.
1410 The "/m" option is now considered deprecated: its "source-centric"
1411 output hasn't proved useful in practice.
1413 * The "record instruction-history" command accepts a new modifier: /s.
1414 It behaves exactly like /m and prints mixed source+disassembly.
1416 * The "set scheduler-locking" command supports a new mode "replay".
1417 It behaves like "off" in record mode and like "on" in replay mode.
1419 * Support for various ROM monitors has been removed:
1421 target dbug dBUG ROM monitor for Motorola ColdFire
1422 target picobug Motorola picobug monitor
1423 target dink32 DINK32 ROM monitor for PowerPC
1424 target m32r Renesas M32R/D ROM monitor
1425 target mon2000 mon2000 ROM monitor
1426 target ppcbug PPCBUG ROM monitor for PowerPC
1428 * Support for reading/writing memory and extracting values on architectures
1429 whose memory is addressable in units of any integral multiple of 8 bits.
1432 Allows to break when an Ada exception is handled.
1434 * New remote packets
1437 Indicates that an exec system call was executed.
1439 exec-events feature in qSupported
1440 The qSupported packet allows GDB to request support for exec
1441 events using the new 'gdbfeature' exec-event, and the qSupported
1442 response can contain the corresponding 'stubfeature'. Set and
1443 show commands can be used to display whether these features are enabled.
1446 Equivalent to interrupting with the ^C character, but works in
1449 thread created stop reason (T05 create:...)
1450 Indicates that the thread was just created and is stopped at entry.
1452 thread exit stop reply (w exitcode;tid)
1453 Indicates that the thread has terminated.
1456 Enables/disables thread create and exit event reporting. For
1457 example, this is used in non-stop mode when GDB stops a set of
1458 threads and synchronously waits for the their corresponding stop
1459 replies. Without exit events, if one of the threads exits, GDB
1460 would hang forever not knowing that it should no longer expect a
1461 stop for that same thread.
1464 Indicates that there are no resumed threads left in the target (all
1465 threads are stopped). The remote stub reports support for this stop
1466 reply to GDB's qSupported query.
1469 Enables/disables catching syscalls from the inferior process.
1470 The remote stub reports support for this packet to GDB's qSupported query.
1472 syscall_entry stop reason
1473 Indicates that a syscall was just called.
1475 syscall_return stop reason
1476 Indicates that a syscall just returned.
1478 * Extended-remote exec events
1480 ** GDB now has support for exec events on extended-remote Linux targets.
1481 For such targets with Linux kernels 2.5.46 and later, this enables
1482 follow-exec-mode and exec catchpoints.
1484 set remote exec-event-feature-packet
1485 show remote exec-event-feature-packet
1486 Set/show the use of the remote exec event feature.
1488 * Thread names in remote protocol
1490 The reply to qXfer:threads:read may now include a name attribute for each
1493 * Target remote mode fork and exec events
1495 ** GDB now has support for fork and exec events on target remote mode
1496 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1497 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1498 fork and exec catchpoints.
1500 * Remote syscall events
1502 ** GDB now has support for catch syscall on remote Linux targets,
1503 currently enabled on x86/x86_64 architectures.
1505 set remote catch-syscall-packet
1506 show remote catch-syscall-packet
1507 Set/show the use of the remote catch syscall feature.
1511 ** The -var-set-format command now accepts the zero-hexadecimal
1512 format. It outputs data in hexadecimal format with zero-padding on the
1517 ** gdb.InferiorThread objects have a new attribute "global_num",
1518 which refers to the thread's global thread ID. The existing
1519 "num" attribute now refers to the thread's per-inferior number.
1520 See "Per-inferior thread numbers" above.
1521 ** gdb.InferiorThread objects have a new attribute "inferior", which
1522 is the Inferior object the thread belongs to.
1524 *** Changes in GDB 7.10
1526 * Support for process record-replay and reverse debugging on aarch64*-linux*
1527 targets has been added. GDB now supports recording of A64 instruction set
1528 including advance SIMD instructions.
1530 * Support for Sun's version of the "stabs" debug file format has been removed.
1532 * GDB now honors the content of the file /proc/PID/coredump_filter
1533 (PID is the process ID) on GNU/Linux systems. This file can be used
1534 to specify the types of memory mappings that will be included in a
1535 corefile. For more information, please refer to the manual page of
1536 "core(5)". GDB also has a new command: "set use-coredump-filter
1537 on|off". It allows to set whether GDB will read the content of the
1538 /proc/PID/coredump_filter file when generating a corefile.
1540 * The "info os" command on GNU/Linux can now display information on
1542 "info os cpus" Listing of all cpus/cores on the system
1544 * GDB has two new commands: "set serial parity odd|even|none" and
1545 "show serial parity". These allows to set or show parity for the
1548 * The "info source" command now displays the producer string if it was
1549 present in the debug info. This typically includes the compiler version
1550 and may include things like its command line arguments.
1552 * The "info dll", an alias of the "info sharedlibrary" command,
1553 is now available on all platforms.
1555 * Directory names supplied to the "set sysroot" commands may be
1556 prefixed with "target:" to tell GDB to access shared libraries from
1557 the target system, be it local or remote. This replaces the prefix
1558 "remote:". The default sysroot has been changed from "" to
1559 "target:". "remote:" is automatically converted to "target:" for
1560 backward compatibility.
1562 * The system root specified by "set sysroot" will be prepended to the
1563 filename of the main executable (if reported to GDB as absolute by
1564 the operating system) when starting processes remotely, and when
1565 attaching to already-running local or remote processes.
1567 * GDB now supports automatic location and retrieval of executable
1568 files from remote targets. Remote debugging can now be initiated
1569 using only a "target remote" or "target extended-remote" command
1570 (no "set sysroot" or "file" commands are required). See "New remote
1573 * The "dump" command now supports verilog hex format.
1575 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1577 * On GNU/Linux, GDB and gdbserver are now able to access executable
1578 and shared library files without a "set sysroot" command when
1579 attaching to processes running in different mount namespaces from
1580 the debugger. This makes it possible to attach to processes in
1581 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1582 See "New remote packets" below.
1584 * The "tui reg" command now provides completion for all of the
1585 available register groups, including target specific groups.
1587 * The HISTSIZE environment variable is no longer read when determining
1588 the size of GDB's command history. GDB now instead reads the dedicated
1589 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1590 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1595 ** Memory ports can now be unbuffered.
1599 ** gdb.Objfile objects have a new attribute "username",
1600 which is the name of the objfile as specified by the user,
1601 without, for example, resolving symlinks.
1602 ** You can now write frame unwinders in Python.
1603 ** gdb.Type objects have a new method "optimized_out",
1604 returning optimized out gdb.Value instance of this type.
1605 ** gdb.Value objects have new methods "reference_value" and
1606 "const_value" which return a reference to the value and a
1607 "const" version of the value respectively.
1611 maint print symbol-cache
1612 Print the contents of the symbol cache.
1614 maint print symbol-cache-statistics
1615 Print statistics of symbol cache usage.
1617 maint flush-symbol-cache
1618 Flush the contents of the symbol cache.
1622 Start branch trace recording using Branch Trace Store (BTS) format.
1625 Evaluate expression by using the compiler and print result.
1629 Explicit commands for enabling and disabling tui mode.
1632 set mpx bound on i386 and amd64
1633 Support for bound table investigation on Intel MPX enabled applications.
1637 Start branch trace recording using Intel Processor Trace format.
1640 Print information about branch tracing internals.
1642 maint btrace packet-history
1643 Print the raw branch tracing data.
1645 maint btrace clear-packet-history
1646 Discard the stored raw branch tracing data.
1649 Discard all branch tracing data. It will be fetched and processed
1650 anew by the next "record" command.
1655 Renamed from "set debug dwarf2-die".
1656 show debug dwarf-die
1657 Renamed from "show debug dwarf2-die".
1659 set debug dwarf-read
1660 Renamed from "set debug dwarf2-read".
1661 show debug dwarf-read
1662 Renamed from "show debug dwarf2-read".
1664 maint set dwarf always-disassemble
1665 Renamed from "maint set dwarf2 always-disassemble".
1666 maint show dwarf always-disassemble
1667 Renamed from "maint show dwarf2 always-disassemble".
1669 maint set dwarf max-cache-age
1670 Renamed from "maint set dwarf2 max-cache-age".
1671 maint show dwarf max-cache-age
1672 Renamed from "maint show dwarf2 max-cache-age".
1674 set debug dwarf-line
1675 show debug dwarf-line
1676 Control display of debugging info regarding DWARF line processing.
1679 show max-completions
1680 Set the maximum number of candidates to be considered during
1681 completion. The default value is 200. This limit allows GDB
1682 to avoid generating large completion lists, the computation of
1683 which can cause the debugger to become temporarily unresponsive.
1685 set history remove-duplicates
1686 show history remove-duplicates
1687 Control the removal of duplicate history entries.
1689 maint set symbol-cache-size
1690 maint show symbol-cache-size
1691 Control the size of the symbol cache.
1693 set|show record btrace bts buffer-size
1694 Set and show the size of the ring buffer used for branch tracing in
1696 The obtained size may differ from the requested size. Use "info
1697 record" to see the obtained buffer size.
1699 set debug linux-namespaces
1700 show debug linux-namespaces
1701 Control display of debugging info regarding Linux namespaces.
1703 set|show record btrace pt buffer-size
1704 Set and show the size of the ring buffer used for branch tracing in
1705 Intel Processor Trace format.
1706 The obtained size may differ from the requested size. Use "info
1707 record" to see the obtained buffer size.
1709 maint set|show btrace pt skip-pad
1710 Set and show whether PAD packets are skipped when computing the
1713 * The command 'thread apply all' can now support new option '-ascending'
1714 to call its specified command for all threads in ascending order.
1716 * Python/Guile scripting
1718 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1719 special section named `.debug_gdb_scripts'.
1721 * New remote packets
1723 qXfer:btrace-conf:read
1724 Return the branch trace configuration for the current thread.
1726 Qbtrace-conf:bts:size
1727 Set the requested ring buffer size for branch tracing in BTS format.
1730 Enable Intel Procesor Trace-based branch tracing for the current
1731 process. The remote stub reports support for this packet to GDB's
1734 Qbtrace-conf:pt:size
1735 Set the requested ring buffer size for branch tracing in Intel Processor
1739 Indicates a memory breakpoint instruction was executed, irrespective
1740 of whether it was GDB that planted the breakpoint or the breakpoint
1741 is hardcoded in the program. This is required for correct non-stop
1745 Indicates the target stopped for a hardware breakpoint. This is
1746 required for correct non-stop mode operation.
1749 Return information about files on the remote system.
1751 qXfer:exec-file:read
1752 Return the full absolute name of the file that was executed to
1753 create a process running on the remote system.
1756 Select the filesystem on which vFile: operations with filename
1757 arguments will operate. This is required for GDB to be able to
1758 access files on remote targets where the remote stub does not
1759 share a common filesystem with the inferior(s).
1762 Indicates that a fork system call was executed.
1765 Indicates that a vfork system call was executed.
1767 vforkdone stop reason
1768 Indicates that a vfork child of the specified process has executed
1769 an exec or exit, allowing the vfork parent to resume execution.
1771 fork-events and vfork-events features in qSupported
1772 The qSupported packet allows GDB to request support for fork and
1773 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1774 and the qSupported response can contain the corresponding
1775 'stubfeatures'. Set and show commands can be used to display
1776 whether these features are enabled.
1778 * Extended-remote fork events
1780 ** GDB now has support for fork events on extended-remote Linux
1781 targets. For targets with Linux kernels 2.5.60 and later, this
1782 enables follow-fork-mode and detach-on-fork for both fork and
1783 vfork, as well as fork and vfork catchpoints.
1785 * The info record command now shows the recording format and the
1786 branch tracing configuration for the current thread when using
1787 the btrace record target.
1788 For the BTS format, it shows the ring buffer size.
1790 * GDB now has support for DTrace USDT (Userland Static Defined
1791 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1793 * GDB now supports access to vector registers on S/390 GNU/Linux
1796 * Removed command line options
1798 -xdb HP-UX XDB compatibility mode.
1800 * Removed targets and native configurations
1802 HP/PA running HP-UX hppa*-*-hpux*
1803 Itanium running HP-UX ia64-*-hpux*
1805 * New configure options
1808 This configure option allows the user to build GDB with support for
1809 Intel Processor Trace (default: auto). This requires libipt.
1811 --with-libipt-prefix=PATH
1812 Specify the path to the version of libipt that GDB should use.
1813 $PATH/include should contain the intel-pt.h header and
1814 $PATH/lib should contain the libipt.so library.
1816 *** Changes in GDB 7.9.1
1820 ** Xmethods can now specify a result type.
1822 *** Changes in GDB 7.9
1824 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1828 ** You can now access frame registers from Python scripts.
1829 ** New attribute 'producer' for gdb.Symtab objects.
1830 ** gdb.Objfile objects have a new attribute "progspace",
1831 which is the gdb.Progspace object of the containing program space.
1832 ** gdb.Objfile objects have a new attribute "owner".
1833 ** gdb.Objfile objects have a new attribute "build_id",
1834 which is the build ID generated when the file was built.
1835 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1836 ** A new event "gdb.clear_objfiles" has been added, triggered when
1837 selecting a new file to debug.
1838 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1839 ** New function gdb.lookup_objfile.
1841 New events which are triggered when GDB modifies the state of the
1844 ** gdb.events.inferior_call_pre: Function call is about to be made.
1845 ** gdb.events.inferior_call_post: Function call has just been made.
1846 ** gdb.events.memory_changed: A memory location has been altered.
1847 ** gdb.events.register_changed: A register has been altered.
1849 * New Python-based convenience functions:
1851 ** $_caller_is(name [, number_of_frames])
1852 ** $_caller_matches(regexp [, number_of_frames])
1853 ** $_any_caller_is(name [, number_of_frames])
1854 ** $_any_caller_matches(regexp [, number_of_frames])
1856 * GDB now supports the compilation and injection of source code into
1857 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1858 to compile the source code to object code, and if successful, inject
1859 and execute that code within the current context of the inferior.
1860 Currently the C language is supported. The commands used to
1861 interface with this new feature are:
1863 compile code [-raw|-r] [--] [source code]
1864 compile file [-raw|-r] filename
1868 demangle [-l language] [--] name
1869 Demangle "name" in the specified language, or the current language
1870 if elided. This command is renamed from the "maint demangle" command.
1871 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1872 as "maint demangler-warning".
1874 queue-signal signal-name-or-number
1875 Queue a signal to be delivered to the thread when it is resumed.
1877 add-auto-load-scripts-directory directory
1878 Add entries to the list of directories from which to load auto-loaded
1881 maint print user-registers
1882 List all currently available "user" registers.
1884 compile code [-r|-raw] [--] [source code]
1885 Compile, inject, and execute in the inferior the executable object
1886 code produced by compiling the provided source code.
1888 compile file [-r|-raw] filename
1889 Compile and inject into the inferior the executable object code
1890 produced by compiling the source code stored in the filename
1893 * On resume, GDB now always passes the signal the program had stopped
1894 for to the thread the signal was sent to, even if the user changed
1895 threads before resuming. Previously GDB would often (but not
1896 always) deliver the signal to the thread that happens to be current
1899 * Conversely, the "signal" command now consistently delivers the
1900 requested signal to the current thread. GDB now asks for
1901 confirmation if the program had stopped for a signal and the user
1902 switched threads meanwhile.
1904 * "breakpoint always-inserted" modes "off" and "auto" merged.
1906 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1907 won't remove breakpoints from the target until all threads stop,
1908 even in non-stop mode. The "auto" mode has been removed, and "off"
1909 is now the default mode.
1913 set debug symbol-lookup
1914 show debug symbol-lookup
1915 Control display of debugging info regarding symbol lookup.
1919 ** The -list-thread-groups command outputs an exit-code field for
1920 inferiors that have exited.
1924 MIPS SDE mips*-sde*-elf*
1928 Support for these obsolete configurations has been removed.
1930 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1931 SGI Irix-5.x mips-*-irix5*
1932 SGI Irix-6.x mips-*-irix6*
1933 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1934 VAX running Ultrix vax-*-ultrix*
1936 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1937 and "assf"), have been removed. Use the "sharedlibrary" command, or
1938 its alias "share", instead.
1940 *** Changes in GDB 7.8
1942 * New command line options
1945 This is an alias for the --data-directory option.
1947 * GDB supports printing and modifying of variable length automatic arrays
1948 as specified in ISO C99.
1950 * The ARM simulator now supports instruction level tracing
1951 with or without disassembly.
1955 GDB now has support for scripting using Guile. Whether this is
1956 available is determined at configure time.
1957 Guile version 2.0 or greater is required.
1958 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1960 * New commands (for set/show, see "New options" below)
1964 Invoke CODE by passing it to the Guile interpreter.
1968 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1970 info auto-load guile-scripts [regexp]
1971 Print the list of automatically loaded Guile scripts.
1973 * The source command is now capable of sourcing Guile scripts.
1974 This feature is dependent on the debugger being built with Guile support.
1978 set print symbol-loading (off|brief|full)
1979 show print symbol-loading
1980 Control whether to print informational messages when loading symbol
1981 information for a file. The default is "full", but when debugging
1982 programs with large numbers of shared libraries the amount of output
1983 becomes less useful.
1985 set guile print-stack (none|message|full)
1986 show guile print-stack
1987 Show a stack trace when an error is encountered in a Guile script.
1989 set auto-load guile-scripts (on|off)
1990 show auto-load guile-scripts
1991 Control auto-loading of Guile script files.
1993 maint ada set ignore-descriptive-types (on|off)
1994 maint ada show ignore-descriptive-types
1995 Control whether the debugger should ignore descriptive types in Ada
1996 programs. The default is not to ignore the descriptive types. See
1997 the user manual for more details on descriptive types and the intended
1998 usage of this option.
2000 set auto-connect-native-target
2002 Control whether GDB is allowed to automatically connect to the
2003 native target for the run, attach, etc. commands when not connected
2004 to any target yet. See also "target native" below.
2006 set record btrace replay-memory-access (read-only|read-write)
2007 show record btrace replay-memory-access
2008 Control what memory accesses are allowed during replay.
2010 maint set target-async (on|off)
2011 maint show target-async
2012 This controls whether GDB targets operate in synchronous or
2013 asynchronous mode. Normally the default is asynchronous, if it is
2014 available; but this can be changed to more easily debug problems
2015 occurring only in synchronous mode.
2017 set mi-async (on|off)
2019 Control whether MI asynchronous mode is preferred. This supersedes
2020 "set target-async" of previous GDB versions.
2022 * "set target-async" is deprecated as a CLI option and is now an alias
2023 for "set mi-async" (only puts MI into async mode).
2025 * Background execution commands (e.g., "c&", "s&", etc.) are now
2026 possible ``out of the box'' if the target supports them. Previously
2027 the user would need to explicitly enable the possibility with the
2028 "set target-async on" command.
2030 * New features in the GDB remote stub, GDBserver
2032 ** New option --debug-format=option1[,option2,...] allows one to add
2033 additional text to each output. At present only timestamps
2034 are supported: --debug-format=timestamps.
2035 Timestamps can also be turned on with the
2036 "monitor set debug-format timestamps" command from GDB.
2038 * The 'record instruction-history' command now starts counting instructions
2039 at one. This also affects the instruction ranges reported by the
2040 'record function-call-history' command when given the /i modifier.
2042 * The command 'record function-call-history' supports a new modifier '/c' to
2043 indent the function names based on their call stack depth.
2044 The fields for the '/i' and '/l' modifier have been reordered.
2045 The source line range is now prefixed with 'at'.
2046 The instruction range is now prefixed with 'inst'.
2047 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2048 "record instruction-history" and "list" commands.
2050 * The ranges given as arguments to the 'record function-call-history' and
2051 'record instruction-history' commands are now inclusive.
2053 * The btrace record target now supports the 'record goto' command.
2054 For locations inside the execution trace, the back trace is computed
2055 based on the information stored in the execution trace.
2057 * The btrace record target supports limited reverse execution and replay.
2058 The target does not record data and therefore does not allow reading
2059 memory or registers.
2061 * The "catch syscall" command now works on s390*-linux* targets.
2063 * The "compare-sections" command is no longer specific to target
2064 remote. It now works with all targets.
2066 * All native targets are now consistently called "native".
2067 Consequently, the "target child", "target GNU", "target djgpp",
2068 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2069 commands have been replaced with "target native". The QNX/NTO port
2070 leaves the "procfs" target in place and adds a "native" target for
2071 consistency with other ports. The impact on users should be minimal
2072 as these commands previously either throwed an error, or were
2073 no-ops. The target's name is visible in the output of the following
2074 commands: "help target", "info target", "info files", "maint print
2077 * The "target native" command now connects to the native target. This
2078 can be used to launch native programs even when "set
2079 auto-connect-native-target" is set to off.
2081 * GDB now supports access to Intel MPX registers on GNU/Linux.
2083 * Support for Intel AVX-512 registers on GNU/Linux.
2084 Support displaying and modifying Intel AVX-512 registers
2085 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2087 * New remote packets
2089 qXfer:btrace:read's annex
2090 The qXfer:btrace:read packet supports a new annex 'delta' to read
2091 branch trace incrementally.
2095 ** Valid Python operations on gdb.Value objects representing
2096 structs/classes invoke the corresponding overloaded operators if
2098 ** New `Xmethods' feature in the Python API. Xmethods are
2099 additional methods or replacements for existing methods of a C++
2100 class. This feature is useful for those cases where a method
2101 defined in C++ source code could be inlined or optimized out by
2102 the compiler, making it unavailable to GDB.
2105 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2107 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2108 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2109 its alias "share", instead.
2111 * The commands "set remotebaud" and "show remotebaud" are no longer
2112 supported. Use "set serial baud" and "show serial baud" (respectively)
2117 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2118 target-async". The latter is left as a deprecated alias of the
2119 former for backward compatibility. If the target supports it,
2120 CLI background execution commands are now always possible by
2121 default, independently of whether the frontend stated a
2122 preference for asynchronous execution with "-gdb-set mi-async".
2123 Previously "-gdb-set target-async off" affected both MI execution
2124 commands and CLI execution commands.
2126 *** Changes in GDB 7.7
2128 * Improved support for process record-replay and reverse debugging on
2129 arm*-linux* targets. Support for thumb32 and syscall instruction
2130 recording has been added.
2132 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2134 * GDB now supports Fission DWP file format version 2.
2135 http://gcc.gnu.org/wiki/DebugFission
2137 * New convenience function "$_isvoid", to check whether an expression
2138 is void. A void expression is an expression where the type of the
2139 result is "void". For example, some convenience variables may be
2140 "void" when evaluated (e.g., "$_exitcode" before the execution of
2141 the program being debugged; or an undefined convenience variable).
2142 Another example, when calling a function whose return type is
2145 * The "maintenance print objfiles" command now takes an optional regexp.
2147 * The "catch syscall" command now works on arm*-linux* targets.
2149 * GDB now consistently shows "<not saved>" when printing values of
2150 registers the debug info indicates have not been saved in the frame
2151 and there's nowhere to retrieve them from
2152 (callee-saved/call-clobbered registers):
2157 (gdb) info registers rax
2160 Before, the former would print "<optimized out>", and the latter
2161 "*value not available*".
2163 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2168 ** Frame filters and frame decorators have been added.
2169 ** Temporary breakpoints are now supported.
2170 ** Line tables representation has been added.
2171 ** New attribute 'parent_type' for gdb.Field objects.
2172 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2173 ** New attribute 'name' for gdb.Type objects.
2177 Nios II ELF nios2*-*-elf
2178 Nios II GNU/Linux nios2*-*-linux
2179 Texas Instruments MSP430 msp430*-*-elf
2181 * Removed native configurations
2183 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2184 been removed. ELF variants of these configurations are kept supported.
2186 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2187 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2188 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2189 i[34567]86-*-openbsd3.[0-3]
2190 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2191 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2192 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2196 Like "catch throw", but catches a re-thrown exception.
2197 maint check-psymtabs
2198 Renamed from old "maint check-symtabs".
2200 Perform consistency checks on symtabs.
2201 maint expand-symtabs
2202 Expand symtabs matching an optional regexp.
2205 Display the details of GDB configure-time options.
2207 maint set|show per-command
2208 maint set|show per-command space
2209 maint set|show per-command time
2210 maint set|show per-command symtab
2211 Enable display of per-command gdb resource usage.
2213 remove-symbol-file FILENAME
2214 remove-symbol-file -a ADDRESS
2215 Remove a symbol file added via add-symbol-file. The file to remove
2216 can be identified by its filename or by an address that lies within
2217 the boundaries of this symbol file in memory.
2220 info exceptions REGEXP
2221 Display the list of Ada exceptions defined in the program being
2222 debugged. If provided, only the exceptions whose names match REGEXP
2227 set debug symfile off|on
2229 Control display of debugging info regarding reading symbol files and
2230 symbol tables within those files
2232 set print raw frame-arguments
2233 show print raw frame-arguments
2234 Set/show whether to print frame arguments in raw mode,
2235 disregarding any defined pretty-printers.
2237 set remote trace-status-packet
2238 show remote trace-status-packet
2239 Set/show the use of remote protocol qTStatus packet.
2243 Control display of debugging messages related to Nios II targets.
2247 Control whether target-assisted range stepping is enabled.
2249 set startup-with-shell
2250 show startup-with-shell
2251 Specifies whether Unix child processes are started via a shell or
2256 Use the target memory cache for accesses to the code segment. This
2257 improves performance of remote debugging (particularly disassembly).
2259 * You can now use a literal value 'unlimited' for options that
2260 interpret 0 or -1 as meaning "unlimited". E.g., "set
2261 trace-buffer-size unlimited" is now an alias for "set
2262 trace-buffer-size -1" and "set height unlimited" is now an alias for
2265 * The "set debug symtab-create" debugging option of GDB has been changed to
2266 accept a verbosity level. 0 means "off", 1 provides basic debugging
2267 output, and values of 2 or greater provides more verbose output.
2269 * New command-line options
2271 Display the details of GDB configure-time options.
2273 * The command 'tsave' can now support new option '-ctf' to save trace
2274 buffer in Common Trace Format.
2276 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2279 * GDB now implements the the C++ 'typeid' operator.
2281 * The new convenience variable $_exception holds the exception being
2282 thrown or caught at an exception-related catchpoint.
2284 * The exception-related catchpoints, like "catch throw", now accept a
2285 regular expression which can be used to filter exceptions by type.
2287 * The new convenience variable $_exitsignal is automatically set to
2288 the terminating signal number when the program being debugged dies
2289 due to an uncaught signal.
2293 ** All MI commands now accept an optional "--language" option.
2294 Support for this feature can be verified by using the "-list-features"
2295 command, which should contain "language-option".
2297 ** The new command -info-gdb-mi-command allows the user to determine
2298 whether a GDB/MI command is supported or not.
2300 ** The "^error" result record returned when trying to execute an undefined
2301 GDB/MI command now provides a variable named "code" whose content is the
2302 "undefined-command" error code. Support for this feature can be verified
2303 by using the "-list-features" command, which should contain
2304 "undefined-command-error-code".
2306 ** The -trace-save MI command can optionally save trace buffer in Common
2309 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2311 ** The command -data-list-register-values now accepts an optional
2312 "--skip-unavailable" option. When used, only the available registers
2315 ** The new command -trace-frame-collected dumps collected variables,
2316 computed expressions, tvars, memory and registers in a traceframe.
2318 ** The commands -stack-list-locals, -stack-list-arguments and
2319 -stack-list-variables now accept an option "--skip-unavailable".
2320 When used, only the available locals or arguments are displayed.
2322 ** The -exec-run command now accepts an optional "--start" option.
2323 When used, the command follows the same semantics as the "start"
2324 command, stopping the program's execution at the start of its
2325 main subprogram. Support for this feature can be verified using
2326 the "-list-features" command, which should contain
2327 "exec-run-start-option".
2329 ** The new commands -catch-assert and -catch-exceptions insert
2330 catchpoints stopping the program when Ada exceptions are raised.
2332 ** The new command -info-ada-exceptions provides the equivalent of
2333 the new "info exceptions" command.
2335 * New system-wide configuration scripts
2336 A GDB installation now provides scripts suitable for use as system-wide
2337 configuration scripts for the following systems:
2341 * GDB now supports target-assigned range stepping with remote targets.
2342 This improves the performance of stepping source lines by reducing
2343 the number of control packets from/to GDB. See "New remote packets"
2346 * GDB now understands the element 'tvar' in the XML traceframe info.
2347 It has the id of the collected trace state variables.
2349 * On S/390 targets that provide the transactional-execution feature,
2350 the program interruption transaction diagnostic block (TDB) is now
2351 represented as a number of additional "registers" in GDB.
2353 * New remote packets
2357 The vCont packet supports a new 'r' action, that tells the remote
2358 stub to step through an address range itself, without GDB
2359 involvemement at each single-step.
2361 qXfer:libraries-svr4:read's annex
2362 The previously unused annex of the qXfer:libraries-svr4:read packet
2363 is now used to support passing an argument list. The remote stub
2364 reports support for this argument list to GDB's qSupported query.
2365 The defined arguments are "start" and "prev", used to reduce work
2366 necessary for library list updating, resulting in significant
2369 * New features in the GDB remote stub, GDBserver
2371 ** GDBserver now supports target-assisted range stepping. Currently
2372 enabled on x86/x86_64 GNU/Linux targets.
2374 ** GDBserver now adds element 'tvar' in the XML in the reply to
2375 'qXfer:traceframe-info:read'. It has the id of the collected
2376 trace state variables.
2378 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2381 * New 'z' formatter for printing and examining memory, this displays the
2382 value as hexadecimal zero padded on the left to the size of the type.
2384 * GDB can now use Windows x64 unwinding data.
2386 * The "set remotebaud" command has been replaced by "set serial baud".
2387 Similarly, "show remotebaud" has been replaced by "show serial baud".
2388 The "set remotebaud" and "show remotebaud" commands are still available
2389 to provide backward compatibility with older versions of GDB.
2391 *** Changes in GDB 7.6
2393 * Target record has been renamed to record-full.
2394 Record/replay is now enabled with the "record full" command.
2395 This also affects settings that are associated with full record/replay
2396 that have been moved from "set/show record" to "set/show record full":
2398 set|show record full insn-number-max
2399 set|show record full stop-at-limit
2400 set|show record full memory-query
2402 * A new record target "record-btrace" has been added. The new target
2403 uses hardware support to record the control-flow of a process. It
2404 does not support replaying the execution, but it implements the
2405 below new commands for investigating the recorded execution log.
2406 This new recording method can be enabled using:
2410 The "record-btrace" target is only available on Intel Atom processors
2411 and requires a Linux kernel 2.6.32 or later.
2413 * Two new commands have been added for record/replay to give information
2414 about the recorded execution without having to replay the execution.
2415 The commands are only supported by "record btrace".
2417 record instruction-history prints the execution history at
2418 instruction granularity
2420 record function-call-history prints the execution history at
2421 function granularity
2423 * New native configurations
2425 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2426 FreeBSD/powerpc powerpc*-*-freebsd
2427 x86_64/Cygwin x86_64-*-cygwin*
2428 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2432 ARM AArch64 aarch64*-*-elf
2433 ARM AArch64 GNU/Linux aarch64*-*-linux
2434 Lynx 178 PowerPC powerpc-*-lynx*178
2435 x86_64/Cygwin x86_64-*-cygwin*
2436 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2438 * If the configured location of system.gdbinit file (as given by the
2439 --with-system-gdbinit option at configure time) is in the
2440 data-directory (as specified by --with-gdb-datadir at configure
2441 time) or in one of its subdirectories, then GDB will look for the
2442 system-wide init file in the directory specified by the
2443 --data-directory command-line option.
2445 * New command line options:
2447 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2448 other initialization files, unlike -nx which disables all of them.
2450 * Removed command line options
2452 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2455 * The 'ptype' and 'whatis' commands now accept an argument to control
2458 * 'info proc' now works on some core files.
2462 ** Vectors can be created with gdb.Type.vector.
2464 ** Python's atexit.register now works in GDB.
2466 ** Types can be pretty-printed via a Python API.
2468 ** Python 3 is now supported (in addition to Python 2.4 or later)
2470 ** New class gdb.Architecture exposes GDB's internal representation
2471 of architecture in the Python API.
2473 ** New method Frame.architecture returns the gdb.Architecture object
2474 corresponding to the frame's architecture.
2476 * New Python-based convenience functions:
2478 ** $_memeq(buf1, buf2, length)
2479 ** $_streq(str1, str2)
2481 ** $_regex(str, regex)
2483 * The 'cd' command now defaults to using '~' (the home directory) if not
2486 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2487 default for GCC since November 2000.
2489 * The command 'forward-search' can now be abbreviated as 'fo'.
2491 * The command 'info tracepoints' can now display 'installed on target'
2492 or 'not installed on target' for each non-pending location of tracepoint.
2494 * New configure options
2496 --enable-libmcheck/--disable-libmcheck
2497 By default, development versions are built with -lmcheck on hosts
2498 that support it, in order to help track memory corruption issues.
2499 Release versions, on the other hand, are built without -lmcheck
2500 by default. The --enable-libmcheck/--disable-libmcheck configure
2501 options allow the user to override that default.
2502 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2503 This configure option allows the user to build GDB with
2504 libbabeltrace using which GDB can read Common Trace Format data.
2506 * New commands (for set/show, see "New options" below)
2509 Catch signals. This is similar to "handle", but allows commands and
2510 conditions to be attached.
2513 List the BFDs known to GDB.
2515 python-interactive [command]
2517 Start a Python interactive prompt, or evaluate the optional command
2518 and print the result of expressions.
2521 "py" is a new alias for "python".
2523 enable type-printer [name]...
2524 disable type-printer [name]...
2525 Enable or disable type printers.
2529 ** For the Renesas Super-H architecture, the "regs" command has been removed
2530 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2535 set print type methods (on|off)
2536 show print type methods
2537 Control whether method declarations are displayed by "ptype".
2538 The default is to show them.
2540 set print type typedefs (on|off)
2541 show print type typedefs
2542 Control whether typedef definitions are displayed by "ptype".
2543 The default is to show them.
2545 set filename-display basename|relative|absolute
2546 show filename-display
2547 Control the way in which filenames is displayed.
2548 The default is "relative", which preserves previous behavior.
2550 set trace-buffer-size
2551 show trace-buffer-size
2552 Request target to change the size of trace buffer.
2554 set remote trace-buffer-size-packet auto|on|off
2555 show remote trace-buffer-size-packet
2556 Control the use of the remote protocol `QTBuffer:size' packet.
2560 Control display of debugging messages related to ARM AArch64.
2563 set debug coff-pe-read
2564 show debug coff-pe-read
2565 Control display of debugging messages related to reading of COFF/PE
2570 Control display of debugging messages related to Mach-O symbols
2573 set debug notification
2574 show debug notification
2575 Control display of debugging info for async remote notification.
2579 ** Command parameter changes are now notified using new async record
2580 "=cmd-param-changed".
2581 ** Trace frame changes caused by command "tfind" are now notified using
2582 new async record "=traceframe-changed".
2583 ** The creation, deletion and modification of trace state variables
2584 are now notified using new async records "=tsv-created",
2585 "=tsv-deleted" and "=tsv-modified".
2586 ** The start and stop of process record are now notified using new
2587 async record "=record-started" and "=record-stopped".
2588 ** Memory changes are now notified using new async record
2590 ** The data-disassemble command response will include a "fullname" field
2591 containing the absolute file name when source has been requested.
2592 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2593 command, to allow pattern filling of memory areas.
2594 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2595 library load/unload events.
2596 ** The response to breakpoint commands and breakpoint async records
2597 includes an "installed" field containing a boolean state about each
2598 non-pending tracepoint location is whether installed on target or not.
2599 ** Output of the "-trace-status" command includes a "trace-file" field
2600 containing the name of the trace file being examined. This field is
2601 optional, and only present when examining a trace file.
2602 ** The "fullname" field is now always present along with the "file" field,
2603 even if the file cannot be found by GDB.
2605 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2606 You must have the LZMA library available when configuring GDB for this
2607 feature to be enabled. For more information, see:
2608 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2610 * New remote packets
2613 Set the size of trace buffer. The remote stub reports support for this
2614 packet to gdb's qSupported query.
2617 Enable Branch Trace Store (BTS)-based branch tracing for the current
2618 thread. The remote stub reports support for this packet to gdb's
2622 Disable branch tracing for the current thread. The remote stub reports
2623 support for this packet to gdb's qSupported query.
2626 Read the traced branches for the current thread. The remote stub
2627 reports support for this packet to gdb's qSupported query.
2629 *** Changes in GDB 7.5
2631 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2632 for more x32 ABI info.
2634 * GDB now supports access to MIPS DSP registers on Linux targets.
2636 * GDB now supports debugging microMIPS binaries.
2638 * The "info os" command on GNU/Linux can now display information on
2639 several new classes of objects managed by the operating system:
2640 "info os procgroups" lists process groups
2641 "info os files" lists file descriptors
2642 "info os sockets" lists internet-domain sockets
2643 "info os shm" lists shared-memory regions
2644 "info os semaphores" lists semaphores
2645 "info os msg" lists message queues
2646 "info os modules" lists loaded kernel modules
2648 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2649 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2650 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2651 options and inspect the probe arguments using the new $_probe_arg family
2652 of convenience variables. You can obtain more information about SystemTap
2653 in <http://sourceware.org/systemtap/>.
2655 * GDB now supports reversible debugging on ARM, it allows you to
2656 debug basic ARM and THUMB instructions, and provides
2657 record/replay support.
2659 * The option "symbol-reloading" has been deleted as it is no longer used.
2663 ** GDB commands implemented in Python can now be put in command class
2666 ** The "maint set python print-stack on|off" is now deleted.
2668 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2669 apply "flag enum"-style pretty-printing to any enum.
2671 ** gdb.lookup_symbol can now work when there is no current frame.
2673 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2674 the source at which the symbol was defined.
2676 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2677 method 'value'. The former indicates whether the symbol needs a
2678 frame in order to compute its value, and the latter computes the
2681 ** A new method 'referenced_value' on gdb.Value objects which can
2682 dereference pointer as well as C++ reference values.
2684 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2685 which return the global and static blocks (as gdb.Block objects),
2686 of the underlying symbol table, respectively.
2688 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2689 object associated with a PC value.
2691 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2692 of the address range occupied by code for the current source line.
2694 * Go language support.
2695 GDB now supports debugging programs written in the Go programming
2698 * GDBserver now supports stdio connections.
2699 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2701 * The binary "gdbtui" can no longer be built or installed.
2702 Use "gdb -tui" instead.
2704 * GDB will now print "flag" enums specially. A flag enum is one where
2705 all the enumerator values have no bits in common when pairwise
2706 "and"ed. When printing a value whose type is a flag enum, GDB will
2707 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2708 (gdb) print (enum E) 3
2711 * The filename part of a linespec will now match trailing components
2712 of a source file name. For example, "break gcc/expr.c:1000" will
2713 now set a breakpoint in build/gcc/expr.c, but not
2714 build/libcpp/expr.c.
2716 * The "info proc" and "generate-core-file" commands will now also
2717 work on remote targets connected to GDBserver on Linux.
2719 * The command "info catch" has been removed. It has been disabled
2720 since December 2007.
2722 * The "catch exception" and "catch assert" commands now accept
2723 a condition at the end of the command, much like the "break"
2724 command does. For instance:
2726 (gdb) catch exception Constraint_Error if Barrier = True
2728 Previously, it was possible to add a condition to such catchpoints,
2729 but it had to be done as a second step, after the catchpoint had been
2730 created, using the "condition" command.
2732 * The "info static-tracepoint-marker" command will now also work on
2733 native Linux targets with in-process agent.
2735 * GDB can now set breakpoints on inlined functions.
2737 * The .gdb_index section has been updated to include symbols for
2738 inlined functions. GDB will ignore older .gdb_index sections by
2739 default, which could cause symbol files to be loaded more slowly
2740 until their .gdb_index sections can be recreated. The new command
2741 "set use-deprecated-index-sections on" will cause GDB to use any older
2742 .gdb_index sections it finds. This will restore performance, but the
2743 ability to set breakpoints on inlined functions will be lost in symbol
2744 files with older .gdb_index sections.
2746 The .gdb_index section has also been updated to record more information
2747 about each symbol. This speeds up the "info variables", "info functions"
2748 and "info types" commands when used with programs having the .gdb_index
2749 section, as well as speeding up debugging with shared libraries using
2750 the .gdb_index section.
2752 * Ada support for GDB/MI Variable Objects has been added.
2754 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2759 ** New command -info-os is the MI equivalent of "info os".
2761 ** Output logs ("set logging" and related) now include MI output.
2765 ** "set use-deprecated-index-sections on|off"
2766 "show use-deprecated-index-sections on|off"
2767 Controls the use of deprecated .gdb_index sections.
2769 ** "catch load" and "catch unload" can be used to stop when a shared
2770 library is loaded or unloaded, respectively.
2772 ** "enable count" can be used to auto-disable a breakpoint after
2775 ** "info vtbl" can be used to show the virtual method tables for
2776 C++ and Java objects.
2778 ** "explore" and its sub commands "explore value" and "explore type"
2779 can be used to recursively explore values and types of
2780 expressions. These commands are available only if GDB is
2781 configured with '--with-python'.
2783 ** "info auto-load" shows status of all kinds of auto-loaded files,
2784 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2785 sequences of commands files, "info auto-load python-scripts"
2786 shows status of auto-loading Python script files,
2787 "info auto-load local-gdbinit" shows status of loading init file
2788 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2789 status of inferior specific thread debugging shared library loading.
2791 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2792 and "show auto-load-scripts" commands have been deprecated, use their
2793 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2794 and "show auto-load python-scripts" counterparts instead.
2796 ** "dprintf location,format,args..." creates a dynamic printf, which
2797 is basically a breakpoint that does a printf and immediately
2798 resumes your program's execution, so it is like a printf that you
2799 can insert dynamically at runtime instead of at compiletime.
2801 ** "set print symbol"
2803 Controls whether GDB attempts to display the symbol, if any,
2804 corresponding to addresses it prints. This defaults to "on", but
2805 you can set it to "off" to restore GDB's previous behavior.
2807 * Deprecated commands
2809 ** For the Renesas Super-H architecture, the "regs" command has been
2810 deprecated, and "info all-registers" should be used instead.
2814 Renesas RL78 rl78-*-elf
2815 HP OpenVMS ia64 ia64-hp-openvms*
2817 * GDBserver supports evaluation of breakpoint conditions. When
2818 support is advertised by GDBserver, GDB may be told to send the
2819 breakpoint conditions in bytecode form to GDBserver. GDBserver
2820 will only report the breakpoint trigger to GDB when its condition
2825 set mips compression
2826 show mips compression
2827 Select the compressed ISA encoding used in functions that have no symbol
2828 information available. The encoding can be set to either of:
2831 and is updated automatically from ELF file flags if available.
2833 set breakpoint condition-evaluation
2834 show breakpoint condition-evaluation
2835 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2836 GDBserver ("target"). Default option "auto" chooses the most efficient
2838 This option can improve debugger efficiency depending on the speed of the
2842 Disable auto-loading globally.
2845 Show auto-loading setting of all kinds of auto-loaded files.
2847 set auto-load gdb-scripts on|off
2848 show auto-load gdb-scripts
2849 Control auto-loading of GDB canned sequences of commands files.
2851 set auto-load python-scripts on|off
2852 show auto-load python-scripts
2853 Control auto-loading of Python script files.
2855 set auto-load local-gdbinit on|off
2856 show auto-load local-gdbinit
2857 Control loading of init file (.gdbinit) from current directory.
2859 set auto-load libthread-db on|off
2860 show auto-load libthread-db
2861 Control auto-loading of inferior specific thread debugging shared library.
2863 set auto-load scripts-directory <dir1>[:<dir2>...]
2864 show auto-load scripts-directory
2865 Set a list of directories from which to load auto-loaded scripts.
2866 Automatically loaded Python scripts and GDB scripts are located in one
2867 of the directories listed by this option.
2868 The delimiter (':' above) may differ according to the host platform.
2870 set auto-load safe-path <dir1>[:<dir2>...]
2871 show auto-load safe-path
2872 Set a list of directories from which it is safe to auto-load files.
2873 The delimiter (':' above) may differ according to the host platform.
2875 set debug auto-load on|off
2876 show debug auto-load
2877 Control display of debugging info for auto-loading the files above.
2879 set dprintf-style gdb|call|agent
2881 Control the way in which a dynamic printf is performed; "gdb"
2882 requests a GDB printf command, while "call" causes dprintf to call a
2883 function in the inferior. "agent" requests that the target agent
2884 (such as GDBserver) do the printing.
2886 set dprintf-function <expr>
2887 show dprintf-function
2888 set dprintf-channel <expr>
2889 show dprintf-channel
2890 Set the function and optional first argument to the call when using
2891 the "call" style of dynamic printf.
2893 set disconnected-dprintf on|off
2894 show disconnected-dprintf
2895 Control whether agent-style dynamic printfs continue to be in effect
2896 after GDB disconnects.
2898 * New configure options
2900 --with-auto-load-dir
2901 Configure default value for the 'set auto-load scripts-directory'
2902 setting above. It defaults to '$debugdir:$datadir/auto-load',
2903 $debugdir representing global debugging info directories (available
2904 via 'show debug-file-directory') and $datadir representing GDB's data
2905 directory (available via 'show data-directory').
2907 --with-auto-load-safe-path
2908 Configure default value for the 'set auto-load safe-path' setting
2909 above. It defaults to the --with-auto-load-dir setting.
2911 --without-auto-load-safe-path
2912 Set 'set auto-load safe-path' to '/', effectively disabling this
2915 * New remote packets
2917 z0/z1 conditional breakpoints extension
2919 The z0/z1 breakpoint insertion packets have been extended to carry
2920 a list of conditional expressions over to the remote stub depending on the
2921 condition evaluation mode. The use of this extension can be controlled
2922 via the "set remote conditional-breakpoints-packet" command.
2926 Specify the signals which the remote stub may pass to the debugged
2927 program without GDB involvement.
2929 * New command line options
2931 --init-command=FILE, -ix Like --command, -x but execute it
2932 before loading inferior.
2933 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2934 execute it before loading inferior.
2936 *** Changes in GDB 7.4
2938 * GDB now handles ambiguous linespecs more consistently; the existing
2939 FILE:LINE support has been expanded to other types of linespecs. A
2940 breakpoint will now be set on all matching locations in all
2941 inferiors, and locations will be added or removed according to
2944 * GDB now allows you to skip uninteresting functions and files when
2945 stepping with the "skip function" and "skip file" commands.
2947 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2948 and "show remote hardware-watchpoint-length-limit". These allows to
2949 set or show the maximum length limit (in bytes) of a remote
2950 target hardware watchpoint.
2952 This allows e.g. to use "unlimited" hardware watchpoints with the
2953 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2954 watchpoints are slower than real hardware watchpoints but are
2955 significantly faster than gdb software watchpoints.
2959 ** The register_pretty_printer function in module gdb.printing now takes
2960 an optional `replace' argument. If True, the new printer replaces any
2963 ** The "maint set python print-stack on|off" command has been
2964 deprecated and will be deleted in GDB 7.5.
2965 A new command: "set python print-stack none|full|message" has
2966 replaced it. Additionally, the default for "print-stack" is
2967 now "message", which just prints the error message without
2970 ** A prompt substitution hook (prompt_hook) is now available to the
2973 ** A new Python module, gdb.prompt has been added to the GDB Python
2974 modules library. This module provides functionality for
2975 escape sequences in prompts (used by set/show
2976 extended-prompt). These escape sequences are replaced by their
2977 corresponding value.
2979 ** Python commands and convenience-functions located in
2980 'data-directory'/python/gdb/command and
2981 'data-directory'/python/gdb/function are now automatically loaded
2984 ** Blocks now provide four new attributes. global_block and
2985 static_block will return the global and static blocks
2986 respectively. is_static and is_global are boolean attributes
2987 that indicate if the block is one of those two types.
2989 ** Symbols now provide the "type" attribute, the type of the symbol.
2991 ** The "gdb.breakpoint" function has been deprecated in favor of
2994 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2995 of a function. This class is based on the "finish" command
2996 available in the CLI.
2998 ** Type objects for struct and union types now allow access to
2999 the fields using standard Python dictionary (mapping) methods.
3000 For example, "some_type['myfield']" now works, as does
3001 "some_type.items()".
3003 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3006 ** A new function, "deep_items" has been added to the gdb.types
3007 module in the GDB Python modules library. This function returns
3008 an iterator over the fields of a struct or union type. Unlike
3009 the standard Python "iteritems" method, it will recursively traverse
3010 any anonymous fields.
3014 ** "*stopped" events can report several new "reason"s, such as
3017 ** Breakpoint changes are now notified using new async records, like
3018 "=breakpoint-modified".
3020 ** New command -ada-task-info.
3022 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3023 $sdir specifies the default system locations of shared libraries.
3024 $pdir specifies the directory where the libpthread used by the application
3027 GDB no longer looks in $sdir and $pdir after it has searched the directories
3028 mentioned in libthread-db-search-path. If you want to search those
3029 directories, they must be specified in libthread-db-search-path.
3030 The default value of libthread-db-search-path on GNU/Linux and Solaris
3031 systems is now "$sdir:$pdir".
3033 $pdir is not supported by gdbserver, it is currently ignored.
3034 $sdir is supported by gdbserver.
3036 * New configure option --with-iconv-bin.
3037 When using the internationalization support like the one in the GNU C
3038 library, GDB will invoke the "iconv" program to get a list of supported
3039 character sets. If this program lives in a non-standard location, one can
3040 use this option to specify where to find it.
3042 * When natively debugging programs on PowerPC BookE processors running
3043 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3044 watchpoints, which specify a mask in addition to an address to watch.
3045 The mask specifies that some bits of an address (the bits which are
3046 reset in the mask) should be ignored when matching the address accessed
3047 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3048 section in the user manual for more details.
3050 * The new option --once causes GDBserver to stop listening for connections once
3051 the first connection is made. The listening port used by GDBserver will
3052 become available after that.
3054 * New commands "info macros" and "alias" have been added.
3056 * New function parameters suffix @entry specifies value of function parameter
3057 at the time the function got called. Entry values are available only since
3063 "!" is now an alias of the "shell" command.
3064 Note that no space is needed between "!" and SHELL COMMAND.
3068 watch EXPRESSION mask MASK_VALUE
3069 The watch command now supports the mask argument which allows creation
3070 of masked watchpoints, if the current architecture supports this feature.
3072 info auto-load-scripts [REGEXP]
3073 This command was formerly named "maintenance print section-scripts".
3074 It is now generally useful and is no longer a maintenance-only command.
3076 info macro [-all] [--] MACRO
3077 The info macro command has new options `-all' and `--'. The first for
3078 printing all definitions of a macro. The second for explicitly specifying
3079 the end of arguments and the beginning of the macro name in case the macro
3080 name starts with a hyphen.
3082 collect[/s] EXPRESSIONS
3083 The tracepoint collect command now takes an optional modifier "/s"
3084 that directs it to dereference pointer-to-character types and
3085 collect the bytes of memory up to a zero byte. The behavior is
3086 similar to what you see when you use the regular print command on a
3087 string. An optional integer following the "/s" sets a bound on the
3088 number of bytes that will be collected.
3091 The trace start command now interprets any supplied arguments as a
3092 note to be recorded with the trace run, with an effect similar to
3093 setting the variable trace-notes.
3096 The trace stop command now interprets any arguments as a note to be
3097 mentioned along with the tstatus report that the trace was stopped
3098 with a command. The effect is similar to setting the variable
3101 * Tracepoints can now be enabled and disabled at any time after a trace
3102 experiment has been started using the standard "enable" and "disable"
3103 commands. It is now possible to start a trace experiment with no enabled
3104 tracepoints; GDB will display a warning, but will allow the experiment to
3105 begin, assuming that tracepoints will be enabled as needed while the trace
3108 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3109 locations with 4-byte instructions, when they were previously
3110 limited to locations with instructions of 5 bytes or longer.
3114 set debug dwarf2-read
3115 show debug dwarf2-read
3116 Turns on or off display of debugging messages related to reading
3117 DWARF debug info. The default is off.
3119 set debug symtab-create
3120 show debug symtab-create
3121 Turns on or off display of debugging messages related to symbol table
3122 creation. The default is off.
3125 show extended-prompt
3126 Set the GDB prompt, and allow escape sequences to be inserted to
3127 display miscellaneous information (see 'help set extended-prompt'
3128 for the list of sequences). This prompt (and any information
3129 accessed through the escape sequences) is updated every time the
3130 prompt is displayed.
3132 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3133 show print entry-values
3134 Set printing of frame argument values at function entry. In some cases
3135 GDB can determine the value of function argument which was passed by the
3136 function caller, even if the value was modified inside the called function.
3138 set debug entry-values
3139 show debug entry-values
3140 Control display of debugging info for determining frame argument values at
3141 function entry and virtual tail call frames.
3143 set basenames-may-differ
3144 show basenames-may-differ
3145 Set whether a source file may have multiple base names.
3146 (A "base name" is the name of a file with the directory part removed.
3147 Example: The base name of "/home/user/hello.c" is "hello.c".)
3148 If set, GDB will canonicalize file names (e.g., expand symlinks)
3149 before comparing them. Canonicalization is an expensive operation,
3150 but it allows the same file be known by more than one base name.
3151 If not set (the default), all source files are assumed to have just
3152 one base name, and gdb will do file name comparisons more efficiently.
3158 Set a user name and notes for the current and any future trace runs.
3159 This is useful for long-running and/or disconnected traces, to
3160 inform others (or yourself) as to who is running the trace, supply
3161 contact information, or otherwise explain what is going on.
3163 set trace-stop-notes
3164 show trace-stop-notes
3165 Set a note attached to the trace run, that is displayed when the
3166 trace has been stopped by a tstop command. This is useful for
3167 instance as an explanation, if you are stopping a trace run that was
3168 started by someone else.
3170 * New remote packets
3174 Dynamically enable a tracepoint in a started trace experiment.
3178 Dynamically disable a tracepoint in a started trace experiment.
3182 Set the user and notes of the trace run.
3186 Query the current status of a tracepoint.
3190 Query the minimum length of instruction at which a fast tracepoint may
3193 * Dcache size (number of lines) and line-size are now runtime-configurable
3194 via "set dcache line" and "set dcache line-size" commands.
3198 Texas Instruments TMS320C6x tic6x-*-*
3202 Renesas RL78 rl78-*-elf
3204 *** Changes in GDB 7.3.1
3206 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3208 *** Changes in GDB 7.3
3210 * GDB has a new command: "thread find [REGEXP]".
3211 It finds the thread id whose name, target id, or thread extra info
3212 matches the given regular expression.
3214 * The "catch syscall" command now works on mips*-linux* targets.
3216 * The -data-disassemble MI command now supports modes 2 and 3 for
3217 dumping the instruction opcodes.
3219 * New command line options
3221 -data-directory DIR Specify DIR as the "data-directory".
3222 This is mostly for testing purposes.
3224 * The "maint set python auto-load on|off" command has been renamed to
3225 "set auto-load-scripts on|off".
3227 * GDB has a new command: "set directories".
3228 It is like the "dir" command except that it replaces the
3229 source path list instead of augmenting it.
3231 * GDB now understands thread names.
3233 On GNU/Linux, "info threads" will display the thread name as set by
3234 prctl or pthread_setname_np.
3236 There is also a new command, "thread name", which can be used to
3237 assign a name internally for GDB to display.
3240 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3241 has been integrated into GDB.
3245 ** The function gdb.Write now accepts an optional keyword 'stream'.
3246 This keyword, when provided, will direct the output to either
3247 stdout, stderr, or GDB's logging output.
3249 ** Parameters can now be be sub-classed in Python, and in particular
3250 you may implement the get_set_doc and get_show_doc functions.
3251 This improves how Parameter set/show documentation is processed
3252 and allows for more dynamic content.
3254 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3255 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3256 have an is_valid method.
3258 ** Breakpoints can now be sub-classed in Python, and in particular
3259 you may implement a 'stop' function that is executed each time
3260 the inferior reaches that breakpoint.
3262 ** New function gdb.lookup_global_symbol looks up a global symbol.
3264 ** GDB values in Python are now callable if the value represents a
3265 function. For example, if 'some_value' represents a function that
3266 takes two integer parameters and returns a value, you can call
3267 that function like so:
3269 result = some_value (10,20)
3271 ** Module gdb.types has been added.
3272 It contains a collection of utilities for working with gdb.Types objects:
3273 get_basic_type, has_field, make_enum_dict.
3275 ** Module gdb.printing has been added.
3276 It contains utilities for writing and registering pretty-printers.
3277 New classes: PrettyPrinter, SubPrettyPrinter,
3278 RegexpCollectionPrettyPrinter.
3279 New function: register_pretty_printer.
3281 ** New commands "info pretty-printers", "enable pretty-printer" and
3282 "disable pretty-printer" have been added.
3284 ** gdb.parameter("directories") is now available.
3286 ** New function gdb.newest_frame returns the newest frame in the
3289 ** The gdb.InferiorThread class has a new "name" attribute. This
3290 holds the thread's name.
3292 ** Python Support for Inferior events.
3293 Python scripts can add observers to be notified of events
3294 occurring in the process being debugged.
3295 The following events are currently supported:
3296 - gdb.events.cont Continue event.
3297 - gdb.events.exited Inferior exited event.
3298 - gdb.events.stop Signal received, and Breakpoint hit events.
3302 ** GDB now puts template parameters in scope when debugging in an
3303 instantiation. For example, if you have:
3305 template<int X> int func (void) { return X; }
3307 then if you step into func<5>, "print X" will show "5". This
3308 feature requires proper debuginfo support from the compiler; it
3309 was added to GCC 4.5.
3311 ** The motion commands "next", "finish", "until", and "advance" now
3312 work better when exceptions are thrown. In particular, GDB will
3313 no longer lose control of the inferior; instead, the GDB will
3314 stop the inferior at the point at which the exception is caught.
3315 This functionality requires a change in the exception handling
3316 code that was introduced in GCC 4.5.
3318 * GDB now follows GCC's rules on accessing volatile objects when
3319 reading or writing target state during expression evaluation.
3320 One notable difference to prior behavior is that "print x = 0"
3321 no longer generates a read of x; the value of the assignment is
3322 now always taken directly from the value being assigned.
3324 * GDB now has some support for using labels in the program's source in
3325 linespecs. For instance, you can use "advance label" to continue
3326 execution to a label.
3328 * GDB now has support for reading and writing a new .gdb_index
3329 section. This section holds a fast index of DWARF debugging
3330 information and can be used to greatly speed up GDB startup and
3331 operation. See the documentation for `save gdb-index' for details.
3333 * The "watch" command now accepts an optional "-location" argument.
3334 When used, this causes GDB to watch the memory referred to by the
3335 expression. Such a watchpoint is never deleted due to it going out
3338 * GDB now supports thread debugging of core dumps on GNU/Linux.
3340 GDB now activates thread debugging using the libthread_db library
3341 when debugging GNU/Linux core dumps, similarly to when debugging
3342 live processes. As a result, when debugging a core dump file, GDB
3343 is now able to display pthread_t ids of threads. For example, "info
3344 threads" shows the same output as when debugging the process when it
3345 was live. In earlier releases, you'd see something like this:
3348 * 1 LWP 6780 main () at main.c:10
3350 While now you see this:
3353 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3355 It is also now possible to inspect TLS variables when debugging core
3358 When debugging a core dump generated on a machine other than the one
3359 used to run GDB, you may need to point GDB at the correct
3360 libthread_db library with the "set libthread-db-search-path"
3361 command. See the user manual for more details on this command.
3363 * When natively debugging programs on PowerPC BookE processors running
3364 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3365 which stop execution of the inferior whenever it executes an instruction
3366 at any address within the specified range. See the "PowerPC Embedded"
3367 section in the user manual for more details.
3369 * New features in the GDB remote stub, GDBserver
3371 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3372 and i686 LynxOS (version 5.x).
3374 ** GDBserver is now supported on Blackfin Linux.
3376 * New native configurations
3378 ia64 HP-UX ia64-*-hpux*
3382 Analog Devices, Inc. Blackfin Processor bfin-*
3384 * Ada task switching is now supported on sparc-elf targets when
3385 debugging a program using the Ravenscar Profile. For more information,
3386 see the "Tasking Support when using the Ravenscar Profile" section
3387 in the GDB user manual.
3389 * Guile support was removed.
3391 * New features in the GNU simulator
3393 ** The --map-info flag lists all known core mappings.
3395 ** CFI flashes may be simulated via the "cfi" device.
3397 *** Changes in GDB 7.2
3399 * Shared library support for remote targets by default
3401 When GDB is configured for a generic, non-OS specific target, like
3402 for example, --target=arm-eabi or one of the many *-*-elf targets,
3403 GDB now queries remote stubs for loaded shared libraries using the
3404 `qXfer:libraries:read' packet. Previously, shared library support
3405 was always disabled for such configurations.
3409 ** Argument Dependent Lookup (ADL)
3411 In C++ ADL lookup directs function search to the namespaces of its
3412 arguments even if the namespace has not been imported.
3422 Here the compiler will search for `foo' in the namespace of 'b'
3423 and find A::foo. GDB now supports this. This construct is commonly
3424 used in the Standard Template Library for operators.
3426 ** Improved User Defined Operator Support
3428 In addition to member operators, GDB now supports lookup of operators
3429 defined in a namespace and imported with a `using' directive, operators
3430 defined in the global scope, operators imported implicitly from an
3431 anonymous namespace, and the ADL operators mentioned in the previous
3433 GDB now also supports proper overload resolution for all the previously
3434 mentioned flavors of operators.
3436 ** static const class members
3438 Printing of static const class members that are initialized in the
3439 class definition has been fixed.
3441 * Windows Thread Information Block access.
3443 On Windows targets, GDB now supports displaying the Windows Thread
3444 Information Block (TIB) structure. This structure is visible either
3445 by using the new command `info w32 thread-information-block' or, by
3446 dereferencing the new convenience variable named `$_tlb', a
3447 thread-specific pointer to the TIB. This feature is also supported
3448 when remote debugging using GDBserver.
3450 * Static tracepoints
3452 Static tracepoints are calls in the user program into a tracing
3453 library. One such library is a port of the LTTng kernel tracer to
3454 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3455 When debugging with GDBserver, GDB now supports combining the GDB
3456 tracepoint machinery with such libraries. For example: the user can
3457 use GDB to probe a static tracepoint marker (a call from the user
3458 program into the tracing library) with the new "strace" command (see
3459 "New commands" below). This creates a "static tracepoint" in the
3460 breakpoint list, that can be manipulated with the same feature set
3461 as fast and regular tracepoints. E.g., collect registers, local and
3462 global variables, collect trace state variables, and define
3463 tracepoint conditions. In addition, the user can collect extra
3464 static tracepoint marker specific data, by collecting the new
3465 $_sdata internal variable. When analyzing the trace buffer, you can
3466 inspect $_sdata like any other variable available to GDB. For more
3467 information, see the "Tracepoints" chapter in GDB user manual. New
3468 remote packets have been defined to support static tracepoints, see
3469 the "New remote packets" section below.
3471 * Better reconstruction of tracepoints after disconnected tracing
3473 GDB will attempt to download the original source form of tracepoint
3474 definitions when starting a trace run, and then will upload these
3475 upon reconnection to the target, resulting in a more accurate
3476 reconstruction of the tracepoints that are in use on the target.
3480 You can now exercise direct control over the ways that GDB can
3481 affect your program. For instance, you can disallow the setting of
3482 breakpoints, so that the program can run continuously (assuming
3483 non-stop mode). In addition, the "observer" variable is available
3484 to switch all of the different controls; in observer mode, GDB
3485 cannot affect the target's behavior at all, which is useful for
3486 tasks like diagnosing live systems in the field.
3488 * The new convenience variable $_thread holds the number of the
3491 * New remote packets
3495 Return the address of the Windows Thread Information Block of a given thread.
3499 In response to several of the tracepoint packets, the target may now
3500 also respond with a number of intermediate `qRelocInsn' request
3501 packets before the final result packet, to have GDB handle
3502 relocating an instruction to execute at a different address. This
3503 is particularly useful for stubs that support fast tracepoints. GDB
3504 reports support for this feature in the qSupported packet.
3508 List static tracepoint markers in the target program.
3512 List static tracepoint markers at a given address in the target
3515 qXfer:statictrace:read
3517 Read the static trace data collected (by a `collect $_sdata'
3518 tracepoint action). The remote stub reports support for this packet
3519 to gdb's qSupported query.
3523 Send the current settings of GDB's permission flags.
3527 Send part of the source (textual) form of a tracepoint definition,
3528 which includes location, conditional, and action list.
3530 * The source command now accepts a -s option to force searching for the
3531 script in the source search path even if the script name specifies
3534 * New features in the GDB remote stub, GDBserver
3536 - GDBserver now support tracepoints (including fast tracepoints, and
3537 static tracepoints). The feature is currently supported by the
3538 i386-linux and amd64-linux builds. See the "Tracepoints support
3539 in gdbserver" section in the manual for more information.
3541 GDBserver JIT compiles the tracepoint's conditional agent
3542 expression bytecode into native code whenever possible for low
3543 overhead dynamic tracepoints conditionals. For such tracepoints,
3544 an expression that examines program state is evaluated when the
3545 tracepoint is reached, in order to determine whether to capture
3546 trace data. If the condition is simple and false, processing the
3547 tracepoint finishes very quickly and no data is gathered.
3549 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3550 for static tracepoints support.
3552 - GDBserver now supports x86_64 Windows 64-bit debugging.
3554 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3555 it understands register description.
3557 * The --batch flag now disables pagination and queries.
3559 * X86 general purpose registers
3561 GDB now supports reading/writing byte, word and double-word x86
3562 general purpose registers directly. This means you can use, say,
3563 $ah or $ax to refer, respectively, to the byte register AH and
3564 16-bit word register AX that are actually portions of the 32-bit
3565 register EAX or 64-bit register RAX.
3567 * The `commands' command now accepts a range of breakpoints to modify.
3568 A plain `commands' following a command that creates multiple
3569 breakpoints affects all the breakpoints set by that command. This
3570 applies to breakpoints set by `rbreak', and also applies when a
3571 single `break' command creates multiple breakpoints (e.g.,
3572 breakpoints on overloaded c++ functions).
3574 * The `rbreak' command now accepts a filename specification as part of
3575 its argument, limiting the functions selected by the regex to those
3576 in the specified file.
3578 * Support for remote debugging Windows and SymbianOS shared libraries
3579 from Unix hosts has been improved. Non Windows GDB builds now can
3580 understand target reported file names that follow MS-DOS based file
3581 system semantics, such as file names that include drive letters and
3582 use the backslash character as directory separator. This makes it
3583 possible to transparently use the "set sysroot" and "set
3584 solib-search-path" on Unix hosts to point as host copies of the
3585 target's shared libraries. See the new command "set
3586 target-file-system-kind" described below, and the "Commands to
3587 specify files" section in the user manual for more information.
3591 eval template, expressions...
3592 Convert the values of one or more expressions under the control
3593 of the string template to a command line, and call it.
3595 set target-file-system-kind unix|dos-based|auto
3596 show target-file-system-kind
3597 Set or show the assumed file system kind for target reported file
3600 save breakpoints <filename>
3601 Save all current breakpoint definitions to a file suitable for use
3602 in a later debugging session. To read the saved breakpoint
3603 definitions, use the `source' command.
3605 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3608 info static-tracepoint-markers
3609 Display information about static tracepoint markers in the target.
3611 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3612 Define a static tracepoint by probing a marker at the given
3613 function, line, address, or marker ID.
3617 Enable and disable observer mode.
3619 set may-write-registers on|off
3620 set may-write-memory on|off
3621 set may-insert-breakpoints on|off
3622 set may-insert-tracepoints on|off
3623 set may-insert-fast-tracepoints on|off
3624 set may-interrupt on|off
3625 Set individual permissions for GDB effects on the target. Note that
3626 some of these settings can have undesirable or surprising
3627 consequences, particularly when changed in the middle of a session.
3628 For instance, disabling the writing of memory can prevent
3629 breakpoints from being inserted, cause single-stepping to fail, or
3630 even crash your program, if you disable after breakpoints have been
3631 inserted. However, GDB should not crash.
3633 set record memory-query on|off
3634 show record memory-query
3635 Control whether to stop the inferior if memory changes caused
3636 by an instruction cannot be recorded.
3641 The disassemble command now supports "start,+length" form of two arguments.
3645 ** GDB now provides a new directory location, called the python directory,
3646 where Python scripts written for GDB can be installed. The location
3647 of that directory is <data-directory>/python, where <data-directory>
3648 is the GDB data directory. For more details, see section `Scripting
3649 GDB using Python' in the manual.
3651 ** The GDB Python API now has access to breakpoints, symbols, symbol
3652 tables, program spaces, inferiors, threads and frame's code blocks.
3653 Additionally, GDB Parameters can now be created from the API, and
3654 manipulated via set/show in the CLI.
3656 ** New functions gdb.target_charset, gdb.target_wide_charset,
3657 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3659 ** New exception gdb.GdbError.
3661 ** Pretty-printers are now also looked up in the current program space.
3663 ** Pretty-printers can now be individually enabled and disabled.
3665 ** GDB now looks for names of Python scripts to auto-load in a
3666 special section named `.debug_gdb_scripts', in addition to looking
3667 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3669 * Tracepoint actions were unified with breakpoint commands. In particular,
3670 there are no longer differences in "info break" output for breakpoints and
3671 tracepoints and the "commands" command can be used for both tracepoints and
3672 regular breakpoints.
3676 ARM Symbian arm*-*-symbianelf*
3678 * D language support.
3679 GDB now supports debugging programs written in the D programming
3682 * GDB now supports the extended ptrace interface for PowerPC which is
3683 available since Linux kernel version 2.6.34. This automatically enables
3684 any hardware breakpoints and additional hardware watchpoints available in
3685 the processor. The old ptrace interface exposes just one hardware
3686 watchpoint and no hardware breakpoints.
3688 * GDB is now able to use the Data Value Compare (DVC) register available on
3689 embedded PowerPC processors to implement in hardware simple watchpoint
3690 conditions of the form:
3692 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3694 This works in native GDB running on Linux kernels with the extended ptrace
3695 interface mentioned above.
3697 *** Changes in GDB 7.1
3701 ** Namespace Support
3703 GDB now supports importing of namespaces in C++. This enables the
3704 user to inspect variables from imported namespaces. Support for
3705 namepace aliasing has also been added. So, if a namespace is
3706 aliased in the current scope (e.g. namepace C=A; ) the user can
3707 print variables using the alias (e.g. (gdb) print C::x).
3711 All known bugs relating to the printing of virtual base class were
3712 fixed. It is now possible to call overloaded static methods using a
3717 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3718 and reinterpret_cast<> are now handled by the C++ expression parser.
3722 Xilinx MicroBlaze microblaze-*-*
3727 Xilinx MicroBlaze microblaze
3730 * Multi-program debugging.
3732 GDB now has support for multi-program (a.k.a. multi-executable or
3733 multi-exec) debugging. This allows for debugging multiple inferiors
3734 simultaneously each running a different program under the same GDB
3735 session. See "Debugging Multiple Inferiors and Programs" in the
3736 manual for more information. This implied some user visible changes
3737 in the multi-inferior support. For example, "info inferiors" now
3738 lists inferiors that are not running yet or that have exited
3739 already. See also "New commands" and "New options" below.
3741 * New tracing features
3743 GDB's tracepoint facility now includes several new features:
3745 ** Trace state variables
3747 GDB tracepoints now include support for trace state variables, which
3748 are variables managed by the target agent during a tracing
3749 experiment. They are useful for tracepoints that trigger each
3750 other, so for instance one tracepoint can count hits in a variable,
3751 and then a second tracepoint has a condition that is true when the
3752 count reaches a particular value. Trace state variables share the
3753 $-syntax of GDB convenience variables, and can appear in both
3754 tracepoint actions and condition expressions. Use the "tvariable"
3755 command to create, and "info tvariables" to view; see "Trace State
3756 Variables" in the manual for more detail.
3760 GDB now includes an option for defining fast tracepoints, which
3761 targets may implement more efficiently, such as by installing a jump
3762 into the target agent rather than a trap instruction. The resulting
3763 speedup can be by two orders of magnitude or more, although the
3764 tradeoff is that some program locations on some target architectures
3765 might not allow fast tracepoint installation, for instance if the
3766 instruction to be replaced is shorter than the jump. To request a
3767 fast tracepoint, use the "ftrace" command, with syntax identical to
3768 the regular trace command.
3770 ** Disconnected tracing
3772 It is now possible to detach GDB from the target while it is running
3773 a trace experiment, then reconnect later to see how the experiment
3774 is going. In addition, a new variable disconnected-tracing lets you
3775 tell the target agent whether to continue running a trace if the
3776 connection is lost unexpectedly.
3780 GDB now has the ability to save the trace buffer into a file, and
3781 then use that file as a target, similarly to you can do with
3782 corefiles. You can select trace frames, print data that was
3783 collected in them, and use tstatus to display the state of the
3784 tracing run at the moment that it was saved. To create a trace
3785 file, use "tsave <filename>", and to use it, do "target tfile
3788 ** Circular trace buffer
3790 You can ask the target agent to handle the trace buffer as a
3791 circular buffer, discarding the oldest trace frames to make room for
3792 newer ones, by setting circular-trace-buffer to on. This feature may
3793 not be available for all target agents.
3798 The disassemble command, when invoked with two arguments, now requires
3799 the arguments to be comma-separated.
3802 The info variables command now displays variable definitions. Files
3803 which only declare a variable are not shown.
3806 The source command is now capable of sourcing Python scripts.
3807 This feature is dependent on the debugger being build with Python
3810 Related to this enhancement is also the introduction of a new command
3811 "set script-extension" (see below).
3813 * New commands (for set/show, see "New options" below)
3815 record save [<FILENAME>]
3816 Save a file (in core file format) containing the process record
3817 execution log for replay debugging at a later time.
3819 record restore <FILENAME>
3820 Restore the process record execution log that was saved at an
3821 earlier time, for replay debugging.
3823 add-inferior [-copies <N>] [-exec <FILENAME>]
3826 clone-inferior [-copies <N>] [ID]
3827 Make a new inferior ready to execute the same program another
3828 inferior has loaded.
3833 maint info program-spaces
3834 List the program spaces loaded into GDB.
3836 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3837 show remote interrupt-sequence
3838 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3839 as the sequence to the remote target in order to interrupt the execution.
3840 Ctrl-C is a default. Some system prefers BREAK which is high level of
3841 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3842 Magic SysRq g. It is BREAK signal and character 'g'.
3844 set remote interrupt-on-connect [on | off]
3845 show remote interrupt-on-connect
3846 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3847 remote target when gdb connects to it. This is needed when you debug
3850 set remotebreak [on | off]
3852 Deprecated. Use "set/show remote interrupt-sequence" instead.
3854 tvariable $NAME [ = EXP ]
3855 Create or modify a trace state variable.
3858 List trace state variables and their values.
3860 delete tvariable $NAME ...
3861 Delete one or more trace state variables.
3864 Evaluate the given expressions without collecting anything into the
3865 trace buffer. (Valid in tracepoint actions only.)
3867 ftrace FN / FILE:LINE / *ADDR
3868 Define a fast tracepoint at the given function, line, or address.
3870 * New expression syntax
3872 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3873 GDB now parses 0b101010 identically with 42.
3877 set follow-exec-mode new|same
3878 show follow-exec-mode
3879 Control whether GDB reuses the same inferior across an exec call or
3880 creates a new one. This is useful to be able to restart the old
3881 executable after the inferior having done an exec call.
3883 set default-collect EXPR, ...
3884 show default-collect
3885 Define a list of expressions to be collected at each tracepoint.
3886 This is a useful way to ensure essential items are not overlooked,
3887 such as registers or a critical global variable.
3889 set disconnected-tracing
3890 show disconnected-tracing
3891 If set to 1, the target is instructed to continue tracing if it
3892 loses its connection to GDB. If 0, the target is to stop tracing
3895 set circular-trace-buffer
3896 show circular-trace-buffer
3897 If set to on, the target is instructed to use a circular trace buffer
3898 and discard the oldest trace frames instead of stopping the trace due
3899 to a full trace buffer. If set to off, the trace stops when the buffer
3900 fills up. Some targets may not support this.
3902 set script-extension off|soft|strict
3903 show script-extension
3904 If set to "off", the debugger does not perform any script language
3905 recognition, and all sourced files are assumed to be GDB scripts.
3906 If set to "soft" (the default), files are sourced according to
3907 filename extension, falling back to GDB scripts if the first
3909 If set to "strict", files are sourced according to filename extension.
3911 set ada trust-PAD-over-XVS on|off
3912 show ada trust-PAD-over-XVS
3913 If off, activate a workaround against a bug in the debugging information
3914 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3915 the GCC sources for more information about the GNAT encoding and
3916 PAD types in particular). It is always safe to set this option to
3917 off, but this introduces a slight performance penalty. The default
3920 * Python API Improvements
3922 ** GDB provides the new class gdb.LazyString. This is useful in
3923 some pretty-printing cases. The new method gdb.Value.lazy_string
3924 provides a simple way to create objects of this type.
3926 ** The fields returned by gdb.Type.fields now have an
3927 `is_base_class' attribute.
3929 ** The new method gdb.Type.range returns the range of an array type.
3931 ** The new method gdb.parse_and_eval can be used to parse and
3932 evaluate an expression.
3934 * New remote packets
3937 Define a trace state variable.
3940 Get the current value of a trace state variable.
3943 Set desired tracing behavior upon disconnection.
3946 Set the trace buffer to be linear or circular.
3949 Get data about the tracepoints currently in use.
3953 Process record now works correctly with hardware watchpoints.
3955 Multiple bug fixes have been made to the mips-irix port, making it
3956 much more reliable. In particular:
3957 - Debugging threaded applications is now possible again. Previously,
3958 GDB would hang while starting the program, or while waiting for
3959 the program to stop at a breakpoint.
3960 - Attaching to a running process no longer hangs.
3961 - An error occurring while loading a core file has been fixed.
3962 - Changing the value of the PC register now works again. This fixes
3963 problems observed when using the "jump" command, or when calling
3964 a function from GDB, or even when assigning a new value to $pc.
3965 - With the "finish" and "return" commands, the return value for functions
3966 returning a small array is now correctly printed.
3967 - It is now possible to break on shared library code which gets executed
3968 during a shared library init phase (code executed while executing
3969 their .init section). Previously, the breakpoint would have no effect.
3970 - GDB is now able to backtrace through the signal handler for
3971 non-threaded programs.
3973 PIE (Position Independent Executable) programs debugging is now supported.
3974 This includes debugging execution of PIC (Position Independent Code) shared
3975 libraries although for that, it should be possible to run such libraries as an
3978 *** Changes in GDB 7.0
3980 * GDB now has an interface for JIT compilation. Applications that
3981 dynamically generate code can create symbol files in memory and register
3982 them with GDB. For users, the feature should work transparently, and
3983 for JIT developers, the interface is documented in the GDB manual in the
3984 "JIT Compilation Interface" chapter.
3986 * Tracepoints may now be conditional. The syntax is as for
3987 breakpoints; either an "if" clause appended to the "trace" command,
3988 or the "condition" command is available. GDB sends the condition to
3989 the target for evaluation using the same bytecode format as is used
3990 for tracepoint actions.
3992 * The disassemble command now supports: an optional /r modifier, print the
3993 raw instructions in hex as well as in symbolic form, and an optional /m
3994 modifier to print mixed source+assembly.
3996 * Process record and replay
3998 In a architecture environment that supports ``process record and
3999 replay'', ``process record and replay'' target can record a log of
4000 the process execution, and replay it with both forward and reverse
4003 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4004 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4005 set execution-direction {forward|reverse}, for targets that support
4008 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4009 feature is available with a native GDB running on kernel version
4012 * GDB now has support for multi-byte and wide character sets on the
4013 target. Strings whose character type is wchar_t, char16_t, or
4014 char32_t are now correctly printed. GDB supports wide- and unicode-
4015 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4016 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4017 `printf'. This feature requires iconv to work properly; if your
4018 system does not have a working iconv, GDB can use GNU libiconv. See
4019 the installation instructions for more information.
4021 * GDB now supports automatic retrieval of shared library files from
4022 remote targets. To use this feature, specify a system root that begins
4023 with the `remote:' prefix, either via the `set sysroot' command or via
4024 the `--with-sysroot' configure-time option.
4026 * "info sharedlibrary" now takes an optional regex of libraries to show,
4027 and it now reports if a shared library has no debugging information.
4029 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4030 now complete on file names.
4032 * When completing in expressions, gdb will attempt to limit
4033 completions to allowable structure or union fields, where appropriate.
4034 For instance, consider:
4036 # struct example { int f1; double f2; };
4037 # struct example variable;
4040 If the user types TAB at the end of this command line, the available
4041 completions will be "f1" and "f2".
4043 * Inlined functions are now supported. They show up in backtraces, and
4044 the "step", "next", and "finish" commands handle them automatically.
4046 * GDB now supports the token-splicing (##) and stringification (#)
4047 operators when expanding macros. It also supports variable-arity
4050 * GDB now supports inspecting extra signal information, exported by
4051 the new $_siginfo convenience variable. The feature is currently
4052 implemented on linux ARM, i386 and amd64.
4054 * GDB can now display the VFP floating point registers and NEON vector
4055 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4056 can provide these registers (requires Linux 2.6.30 or later). Remote
4057 and simulator targets may also provide them.
4059 * New remote packets
4062 Search memory for a sequence of bytes.
4065 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4066 operation over reliable transport links. Use of this packet is
4067 controlled by the `set remote noack-packet' command.
4070 Kill the process with the specified process ID. Use this in preference
4071 to `k' when multiprocess protocol extensions are supported.
4074 Obtains additional operating system information
4078 Read or write additional signal information.
4080 * Removed remote protocol undocumented extension
4082 An undocumented extension to the remote protocol's `S' stop reply
4083 packet that permited the stub to pass a process id was removed.
4084 Remote servers should use the `T' stop reply packet instead.
4086 * GDB now supports multiple function calling conventions according to the
4087 DWARF-2 DW_AT_calling_convention function attribute.
4089 * The SH target utilizes the aforementioned change to distinguish between gcc
4090 and Renesas calling convention. It also adds the new CLI commands
4091 `set/show sh calling-convention'.
4093 * GDB can now read compressed debug sections, as produced by GNU gold
4094 with the --compress-debug-sections=zlib flag.
4096 * 64-bit core files are now supported on AIX.
4098 * Thread switching is now supported on Tru64.
4100 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4101 which will be allocated using malloc later in program execution.
4103 * The qXfer:libraries:read remote procotol packet now allows passing a
4104 list of section offsets.
4106 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4107 conditions handling signals delivered during attach or thread creation
4108 have also been fixed.
4110 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4111 From the user's standpoint, all unqualified instances of True and False
4112 are treated as the standard definitions, regardless of context.
4114 * GDB now parses C++ symbol and type names more flexibly. For
4117 template<typename T> class C { };
4120 GDB will now correctly handle all of:
4122 ptype C<char const *>
4123 ptype C<char const*>
4124 ptype C<const char *>
4125 ptype C<const char*>
4127 * New features in the GDB remote stub, gdbserver
4129 - The "--wrapper" command-line argument tells gdbserver to use a
4130 wrapper program to launch programs for debugging.
4132 - On PowerPC and S/390 targets, it is now possible to use a single
4133 gdbserver executable to debug both 32-bit and 64-bit programs.
4134 (This requires gdbserver itself to be built as a 64-bit executable.)
4136 - gdbserver uses the new noack protocol mode for TCP connections to
4137 reduce communications latency, if also supported and enabled in GDB.
4139 - Support for the sparc64-linux-gnu target is now included in
4142 - The amd64-linux build of gdbserver now supports debugging both
4143 32-bit and 64-bit programs.
4145 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4146 now support hardware watchpoints, and will use them automatically
4151 GDB now has support for scripting using Python. Whether this is
4152 available is determined at configure time.
4154 New GDB commands can now be written in Python.
4156 * Ada tasking support
4158 Ada tasks can now be inspected in GDB. The following commands have
4162 Print the list of Ada tasks.
4164 Print detailed information about task number N.
4166 Print the task number of the current task.
4168 Switch the context of debugging to task number N.
4170 * Support for user-defined prefixed commands. The "define" command can
4171 add new commands to existing prefixes, e.g. "target".
4173 * Multi-inferior, multi-process debugging.
4175 GDB now has generalized support for multi-inferior debugging. See
4176 "Debugging Multiple Inferiors" in the manual for more information.
4177 Although availability still depends on target support, the command
4178 set is more uniform now. The GNU/Linux specific multi-forks support
4179 has been migrated to this new framework. This implied some user
4180 visible changes; see "New commands" and also "Removed commands"
4183 * Target descriptions can now describe the target OS ABI. See the
4184 "Target Description Format" section in the user manual for more
4187 * Target descriptions can now describe "compatible" architectures
4188 to indicate that the target can execute applications for a different
4189 architecture in addition to those for the main target architecture.
4190 See the "Target Description Format" section in the user manual for
4193 * Multi-architecture debugging.
4195 GDB now includes general supports for debugging applications on
4196 hybrid systems that use more than one single processor architecture
4197 at the same time. Each such hybrid architecture still requires
4198 specific support to be added. The only hybrid architecture supported
4199 in this version of GDB is the Cell Broadband Engine.
4201 * GDB now supports integrated debugging of Cell/B.E. applications that
4202 use both the PPU and SPU architectures. To enable support for hybrid
4203 Cell/B.E. debugging, you need to configure GDB to support both the
4204 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4205 --enable-targets configure option.
4207 * Non-stop mode debugging.
4209 For some targets, GDB now supports an optional mode of operation in
4210 which you can examine stopped threads while other threads continue
4211 to execute freely. This is referred to as non-stop mode, with the
4212 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4213 section in the user manual for more information.
4215 To be able to support remote non-stop debugging, a remote stub needs
4216 to implement the non-stop mode remote protocol extensions, as
4217 described in the "Remote Non-Stop" section of the user manual. The
4218 GDB remote stub, gdbserver, has been adjusted to support these
4219 extensions on linux targets.
4221 * New commands (for set/show, see "New options" below)
4223 catch syscall [NAME(S) | NUMBER(S)]
4224 Catch system calls. Arguments, which should be names of system
4225 calls or their numbers, mean catch only those syscalls. Without
4226 arguments, every syscall will be caught. When the inferior issues
4227 any of the specified syscalls, GDB will stop and announce the system
4228 call, both when it is called and when its call returns. This
4229 feature is currently available with a native GDB running on the
4230 Linux Kernel, under the following architectures: x86, x86_64,
4231 PowerPC and PowerPC64.
4233 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4235 Search memory for a sequence of bytes.
4237 maint set python print-stack
4238 maint show python print-stack
4239 Show a stack trace when an error is encountered in a Python script.
4242 Invoke CODE by passing it to the Python interpreter.
4247 These allow macros to be defined, undefined, and listed
4251 Show operating system information about processes.
4254 List the inferiors currently under GDB's control.
4257 Switch focus to inferior number NUM.
4260 Detach from inferior number NUM.
4263 Kill inferior number NUM.
4267 set spu stop-on-load
4268 show spu stop-on-load
4269 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4271 set spu auto-flush-cache
4272 show spu auto-flush-cache
4273 Control whether to automatically flush the software-managed cache
4274 during Cell/B.E. debugging.
4276 set sh calling-convention
4277 show sh calling-convention
4278 Control the calling convention used when calling SH target functions.
4281 show debug timestamp
4282 Control display of timestamps with GDB debugging output.
4284 set disassemble-next-line
4285 show disassemble-next-line
4286 Control display of disassembled source lines or instructions when
4289 set remote noack-packet
4290 show remote noack-packet
4291 Set/show the use of remote protocol QStartNoAckMode packet. See above
4292 under "New remote packets."
4294 set remote query-attached-packet
4295 show remote query-attached-packet
4296 Control use of remote protocol `qAttached' (query-attached) packet.
4298 set remote read-siginfo-object
4299 show remote read-siginfo-object
4300 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4303 set remote write-siginfo-object
4304 show remote write-siginfo-object
4305 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4308 set remote reverse-continue
4309 show remote reverse-continue
4310 Control use of remote protocol 'bc' (reverse-continue) packet.
4312 set remote reverse-step
4313 show remote reverse-step
4314 Control use of remote protocol 'bs' (reverse-step) packet.
4316 set displaced-stepping
4317 show displaced-stepping
4318 Control displaced stepping mode. Displaced stepping is a way to
4319 single-step over breakpoints without removing them from the debuggee.
4320 Also known as "out-of-line single-stepping".
4323 show debug displaced
4324 Control display of debugging info for displaced stepping.
4326 maint set internal-error
4327 maint show internal-error
4328 Control what GDB does when an internal error is detected.
4330 maint set internal-warning
4331 maint show internal-warning
4332 Control what GDB does when an internal warning is detected.
4337 Use a wrapper program to launch programs for debugging.
4339 set multiple-symbols (all|ask|cancel)
4340 show multiple-symbols
4341 The value of this variable can be changed to adjust the debugger behavior
4342 when an expression or a breakpoint location contains an ambiguous symbol
4343 name (an overloaded function name, for instance).
4345 set breakpoint always-inserted
4346 show breakpoint always-inserted
4347 Keep breakpoints always inserted in the target, as opposed to inserting
4348 them when resuming the target, and removing them when the target stops.
4349 This option can improve debugger performance on slow remote targets.
4351 set arm fallback-mode (arm|thumb|auto)
4352 show arm fallback-mode
4353 set arm force-mode (arm|thumb|auto)
4355 These commands control how ARM GDB determines whether instructions
4356 are ARM or Thumb. The default for both settings is auto, which uses
4357 the current CPSR value for instructions without symbols; previous
4358 versions of GDB behaved as if "set arm fallback-mode arm".
4360 set disable-randomization
4361 show disable-randomization
4362 Standalone programs run with the virtual address space randomization enabled
4363 by default on some platforms. This option keeps the addresses stable across
4364 multiple debugging sessions.
4368 Control whether other threads are stopped or not when some thread hits
4373 Requests that asynchronous execution is enabled in the target, if available.
4374 In this case, it's possible to resume target in the background, and interact
4375 with GDB while the target is running. "show target-async" displays the
4376 current state of asynchronous execution of the target.
4378 set target-wide-charset
4379 show target-wide-charset
4380 The target-wide-charset is the name of the character set that GDB
4381 uses when printing characters whose type is wchar_t.
4383 set tcp auto-retry (on|off)
4385 set tcp connect-timeout
4386 show tcp connect-timeout
4387 These commands allow GDB to retry failed TCP connections to a remote stub
4388 with a specified timeout period; this is useful if the stub is launched
4389 in parallel with GDB but may not be ready to accept connections immediately.
4391 set libthread-db-search-path
4392 show libthread-db-search-path
4393 Control list of directories which GDB will search for appropriate
4396 set schedule-multiple (on|off)
4397 show schedule-multiple
4398 Allow GDB to resume all threads of all processes or only threads of
4399 the current process.
4403 Use more aggressive caching for accesses to the stack. This improves
4404 performance of remote debugging (particularly backtraces) without
4405 affecting correctness.
4407 set interactive-mode (on|off|auto)
4408 show interactive-mode
4409 Control whether GDB runs in interactive mode (on) or not (off).
4410 When in interactive mode, GDB waits for the user to answer all
4411 queries. Otherwise, GDB does not wait and assumes the default
4412 answer. When set to auto (the default), GDB determines which
4413 mode to use based on the stdin settings.
4418 For program forks, this is replaced by the new more generic `info
4419 inferiors' command. To list checkpoints, you can still use the
4420 `info checkpoints' command, which was an alias for the `info forks'
4424 Replaced by the new `inferior' command. To switch between
4425 checkpoints, you can still use the `restart' command, which was an
4426 alias for the `fork' command.
4429 This is removed, since some targets don't have a notion of
4430 processes. To switch between processes, you can still use the
4431 `inferior' command using GDB's own inferior number.
4434 For program forks, this is replaced by the new more generic `kill
4435 inferior' command. To delete a checkpoint, you can still use the
4436 `delete checkpoint' command, which was an alias for the `delete
4440 For program forks, this is replaced by the new more generic `detach
4441 inferior' command. To detach a checkpoint, you can still use the
4442 `detach checkpoint' command, which was an alias for the `detach
4445 * New native configurations
4447 x86/x86_64 Darwin i[34567]86-*-darwin*
4449 x86_64 MinGW x86_64-*-mingw*
4453 Lattice Mico32 lm32-*
4454 x86 DICOS i[34567]86-*-dicos*
4455 x86_64 DICOS x86_64-*-dicos*
4458 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4459 (mingw32ce) debugging.
4465 These commands were actually not implemented on any target.
4467 *** Changes in GDB 6.8
4469 * New native configurations
4471 NetBSD/hppa hppa*-*netbsd*
4472 Xtensa GNU/Linux xtensa*-*-linux*
4476 NetBSD/hppa hppa*-*-netbsd*
4477 Xtensa GNU/Lunux xtensa*-*-linux*
4479 * Change in command line behavior -- corefiles vs. process ids.
4481 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4482 attaching to process NUMBER fails, GDB no longer attempts to open a
4483 core file named NUMBER. Attaching to a program using the -c option
4484 is no longer supported. Instead, use the '-p' or '--pid' options.
4486 * GDB can now be built as a native debugger for debugging Windows x86
4487 (mingw32) Portable Executable (PE) programs.
4489 * Pending breakpoints no longer change their number when their address
4492 * GDB now supports breakpoints with multiple locations,
4493 including breakpoints on C++ constructors, inside C++ templates,
4494 and in inlined functions.
4496 * GDB's ability to debug optimized code has been improved. GDB more
4497 accurately identifies function bodies and lexical blocks that occupy
4498 more than one contiguous range of addresses.
4500 * Target descriptions can now describe registers for PowerPC.
4502 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4503 registers on PowerPC targets.
4505 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4506 targets even when the libthread_db library is not available.
4508 * The GDB remote stub, gdbserver, now supports the new file transfer
4509 commands (remote put, remote get, and remote delete).
4511 * The GDB remote stub, gdbserver, now supports run and attach in
4512 extended-remote mode.
4514 * hppa*64*-*-hpux11* target broken
4515 The debugger is unable to start a program and fails with the following
4516 error: "Error trying to get information about dynamic linker".
4517 The gdb-6.7 release is also affected.
4519 * GDB now supports the --enable-targets= configure option to allow
4520 building a single GDB executable that supports multiple remote
4521 target architectures.
4523 * GDB now supports debugging C and C++ programs which use the
4524 Decimal Floating Point extension. In addition, the PowerPC target
4525 now has a set of pseudo-registers to inspect decimal float values
4526 stored in two consecutive float registers.
4528 * The -break-insert MI command can optionally create pending
4531 * Improved support for debugging Ada
4532 Many improvements to the Ada language support have been made. These
4534 - Better support for Ada2005 interface types
4535 - Improved handling of arrays and slices in general
4536 - Better support for Taft-amendment types
4537 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4539 - Improved command completion in Ada
4542 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4547 set print frame-arguments (all|scalars|none)
4548 show print frame-arguments
4549 The value of this variable can be changed to control which argument
4550 values should be printed by the debugger when displaying a frame.
4555 Transfer files to and from a remote target, and delete remote files.
4562 Transfer files to and from a remote target, and delete remote files.
4564 * New remote packets
4571 Open, close, read, write, and delete files on the remote system.
4574 Attach to an existing process on the remote system, in extended-remote
4578 Run a new process on the remote system, in extended-remote mode.
4580 *** Changes in GDB 6.7
4582 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4583 bfd, libiberty and opcodes, as revealed by static analysis donated by
4584 Coverity, Inc. (http://scan.coverity.com).
4586 * When looking up multiply-defined global symbols, GDB will now prefer the
4587 symbol definition in the current shared library if it was built using the
4588 -Bsymbolic linker option.
4590 * When the Text User Interface (TUI) is not configured, GDB will now
4591 recognize the -tui command-line option and print a message that the TUI
4594 * The GDB remote stub, gdbserver, now has lower overhead for high
4595 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4597 * GDB for MIPS targets now autodetects whether a remote target provides
4598 32-bit or 64-bit register values.
4600 * Support for C++ member pointers has been improved.
4602 * GDB now understands XML target descriptions, which specify the
4603 target's overall architecture. GDB can read a description from
4604 a local file or over the remote serial protocol.
4606 * Vectors of single-byte data use a new integer type which is not
4607 automatically displayed as character or string data.
4609 * The /s format now works with the print command. It displays
4610 arrays of single-byte integers and pointers to single-byte integers
4613 * Target descriptions can now describe target-specific registers,
4614 for architectures which have implemented the support (currently
4615 only ARM, M68K, and MIPS).
4617 * GDB and the GDB remote stub, gdbserver, now support the XScale
4620 * The GDB remote stub, gdbserver, has been updated to support
4621 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4622 has been rewritten to use the standard GDB remote protocol.
4624 * GDB can now step into C++ functions which are called through thunks.
4626 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4628 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4629 layout. It also supports a TextSeg= and DataSeg= response when only
4630 segment base addresses (rather than offsets) are available.
4632 * The /i format now outputs any trailing branch delay slot instructions
4633 immediately following the last instruction within the count specified.
4635 * The GDB remote protocol "T" stop reply packet now supports a
4636 "library" response. Combined with the new "qXfer:libraries:read"
4637 packet, this response allows GDB to debug shared libraries on targets
4638 where the operating system manages the list of loaded libraries (e.g.
4639 Windows and SymbianOS).
4641 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4642 (DLLs) on Windows and Windows CE targets.
4644 * GDB now supports a faster verification that a .debug file matches its binary
4645 according to its build-id signature, if the signature is present.
4651 Enable or disable hardware flow control (RTS/CTS) on the serial port
4652 when debugging using remote targets.
4654 set mem inaccessible-by-default
4655 show mem inaccessible-by-default
4656 If the target supplies a memory map, for instance via the remote
4657 protocol's "qXfer:memory-map:read" packet, setting this variable
4658 prevents GDB from accessing memory outside the memory map. This
4659 is useful for targets with memory mapped registers or which react
4660 badly to accesses of unmapped address space.
4662 set breakpoint auto-hw
4663 show breakpoint auto-hw
4664 If the target supplies a memory map, for instance via the remote
4665 protocol's "qXfer:memory-map:read" packet, setting this variable
4666 lets GDB use hardware breakpoints automatically for memory regions
4667 where it can not use software breakpoints. This covers both the
4668 "break" command and internal breakpoints used for other commands
4669 including "next" and "finish".
4672 catch exception unhandled
4673 Stop the program execution when Ada exceptions are raised.
4676 Stop the program execution when an Ada assertion failed.
4680 Set an alternate system root for target files. This is a more
4681 general version of "set solib-absolute-prefix", which is now
4682 an alias to "set sysroot".
4685 Provide extended SPU facility status information. This set of
4686 commands is available only when debugging the Cell/B.E. SPU
4689 * New native configurations
4691 OpenBSD/sh sh*-*openbsd*
4694 unset tdesc filename
4696 Use the specified local file as an XML target description, and do
4697 not query the target for its built-in description.
4701 OpenBSD/sh sh*-*-openbsd*
4702 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4703 Toshiba Media Processor mep-elf
4705 * New remote packets
4708 Ignore the specified signals; pass them directly to the debugged program
4709 without stopping other threads or reporting them to GDB.
4711 qXfer:features:read:
4712 Read an XML target description from the target, which describes its
4717 Read or write contents of an spufs file on the target system. These
4718 packets are available only on the Cell/B.E. SPU architecture.
4720 qXfer:libraries:read:
4721 Report the loaded shared libraries. Combined with new "T" packet
4722 response, this packet allows GDB to debug shared libraries on
4723 targets where the operating system manages the list of loaded
4724 libraries (e.g. Windows and SymbianOS).
4728 Support for these obsolete configurations has been removed.
4736 i[34567]86-*-lynxos*
4737 i[34567]86-*-netware*
4738 i[34567]86-*-sco3.2v5*
4739 i[34567]86-*-sco3.2v4*
4741 i[34567]86-*-sysv4.2*
4744 i[34567]86-*-unixware2*
4745 i[34567]86-*-unixware*
4754 * Other removed features
4761 Various m68k-only ROM monitors.
4768 Various Renesas ROM monitors and debugging interfaces for SH and
4773 Support for a Macraigor serial interface to on-chip debugging.
4774 GDB does not directly support the newer parallel or USB
4779 A debug information format. The predecessor to DWARF 2 and
4780 DWARF 3, which are still supported.
4782 Support for the HP aCC compiler on HP-UX/PA-RISC
4784 SOM-encapsulated symbolic debugging information, automatic
4785 invocation of pxdb, and the aCC custom C++ ABI. This does not
4786 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4787 with aCC can still be debugged on an assembly level.
4789 MIPS ".pdr" sections
4791 A MIPS-specific format used to describe stack frame layout
4792 in debugging information.
4796 GDB could work with an older version of Guile to debug
4797 the interpreter and Scheme programs running in it.
4799 set mips stack-arg-size
4800 set mips saved-gpreg-size
4802 Use "set mips abi" to control parameter passing for MIPS.
4804 *** Changes in GDB 6.6
4809 Cell Broadband Engine SPU spu-elf
4811 * GDB can now be configured as a cross-debugger targeting native Windows
4812 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4813 running on a Windows system over TCP/IP to debug Windows programs.
4815 * The GDB remote stub, gdbserver, has been updated to support Windows and
4816 Cygwin debugging. Both single-threaded and multi-threaded programs are
4819 * The "set trust-readonly-sections" command works again. This command was
4820 broken in GDB 6.3, 6.4, and 6.5.
4822 * The "load" command now supports writing to flash memory, if the remote
4823 stub provides the required support.
4825 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4826 longer requires symbolic debug information (e.g. DWARF-2).
4831 unset substitute-path
4832 show substitute-path
4833 Manage a list of substitution rules that GDB uses to rewrite the name
4834 of the directories where the sources are located. This can be useful
4835 for instance when the sources were moved to a different location
4836 between compilation and debugging.
4840 Print each CLI command as it is executed. Each command is prefixed with
4841 a number of `+' symbols representing the nesting depth.
4842 The source command now has a `-v' option to enable the same feature.
4846 The ARM Demon monitor support (RDP protocol, "target rdp").
4848 Kernel Object Display, an embedded debugging feature which only worked with
4849 an obsolete version of Cisco IOS.
4851 The 'set download-write-size' and 'show download-write-size' commands.
4853 * New remote packets
4856 Tell a stub about GDB client features, and request remote target features.
4857 The first feature implemented is PacketSize, which allows the target to
4858 specify the size of packets it can handle - to minimize the number of
4859 packets required and improve performance when connected to a remote
4863 Fetch an OS auxilliary vector from the remote stub. This packet is a
4864 more efficient replacement for qPart:auxv:read.
4866 qXfer:memory-map:read:
4867 Fetch a memory map from the remote stub, including information about
4868 RAM, ROM, and flash memory devices.
4873 Erase and program a flash memory device.
4875 * Removed remote packets
4878 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4879 used it, and only gdbserver implemented it.
4881 *** Changes in GDB 6.5
4885 Renesas M32C/M16C m32c-elf
4887 Morpho Technologies ms1 ms1-elf
4891 init-if-undefined Initialize a convenience variable, but
4892 only if it doesn't already have a value.
4894 The following commands are presently only implemented for native GNU/Linux:
4896 checkpoint Save a snapshot of the program state.
4898 restart <n> Return the program state to a
4899 previously saved state.
4901 info checkpoints List currently saved checkpoints.
4903 delete-checkpoint <n> Delete a previously saved checkpoint.
4905 set|show detach-on-fork Tell gdb whether to detach from a newly
4906 forked process, or to keep debugging it.
4908 info forks List forks of the user program that
4909 are available to be debugged.
4911 fork <n> Switch to debugging one of several
4912 forks of the user program that are
4913 available to be debugged.
4915 delete-fork <n> Delete a fork from the list of forks
4916 that are available to be debugged (and
4917 kill the forked process).
4919 detach-fork <n> Delete a fork from the list of forks
4920 that are available to be debugged (and
4921 allow the process to continue).
4925 Morpho Technologies ms2 ms1-elf
4927 * Improved Windows host support
4929 GDB now builds as a cross debugger hosted on i686-mingw32, including
4930 native console support, and remote communications using either
4931 network sockets or serial ports.
4933 * Improved Modula-2 language support
4935 GDB can now print most types in the Modula-2 syntax. This includes:
4936 basic types, set types, record types, enumerated types, range types,
4937 pointer types and ARRAY types. Procedure var parameters are correctly
4938 printed and hexadecimal addresses and character constants are also
4939 written in the Modula-2 syntax. Best results can be obtained by using
4940 GNU Modula-2 together with the -gdwarf-2 command line option.
4944 The ARM rdi-share module.
4946 The Netware NLM debug server.
4948 *** Changes in GDB 6.4
4950 * New native configurations
4952 OpenBSD/arm arm*-*-openbsd*
4953 OpenBSD/mips64 mips64-*-openbsd*
4957 Morpho Technologies ms1 ms1-elf
4959 * New command line options
4961 --batch-silent As for --batch, but totally silent.
4962 --return-child-result The debugger will exist with the same value
4963 the child (debugged) program exited with.
4964 --eval-command COMMAND, -ex COMMAND
4965 Execute a single GDB CLI command. This may be
4966 specified multiple times and in conjunction
4967 with the --command (-x) option.
4969 * Deprecated commands removed
4971 The following commands, that were deprecated in 2000, have been
4975 set|show arm disassembly-flavor set|show arm disassembler
4976 othernames set arm disassembler
4977 set|show remotedebug set|show debug remote
4978 set|show archdebug set|show debug arch
4979 set|show eventdebug set|show debug event
4982 * New BSD user-level threads support
4984 It is now possible to debug programs using the user-level threads
4985 library on OpenBSD and FreeBSD. Currently supported (target)
4988 FreeBSD/amd64 x86_64-*-freebsd*
4989 FreeBSD/i386 i386-*-freebsd*
4990 OpenBSD/i386 i386-*-openbsd*
4992 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4993 are not yet supported.
4995 * New support for Matsushita MN10300 w/sim added
4996 (Work in progress). mn10300-elf.
4998 * REMOVED configurations and files
5000 VxWorks and the XDR protocol *-*-vxworks
5001 Motorola MCORE mcore-*-*
5002 National Semiconductor NS32000 ns32k-*-*
5004 * New "set print array-indexes" command
5006 After turning this setting "on", GDB prints the index of each element
5007 when displaying arrays. The default is "off" to preserve the previous
5010 * VAX floating point support
5012 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5014 * User-defined command support
5016 In addition to using $arg0..$arg9 for argument passing, it is now possible
5017 to use $argc to determine now many arguments have been passed. See the
5018 section on user-defined commands in the user manual for more information.
5020 *** Changes in GDB 6.3:
5022 * New command line option
5024 GDB now accepts -l followed by a number to set the timeout for remote
5027 * GDB works with GCC -feliminate-dwarf2-dups
5029 GDB now supports a more compact representation of DWARF-2 debug
5030 information using DW_FORM_ref_addr references. These are produced
5031 by GCC with the option -feliminate-dwarf2-dups and also by some
5032 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5033 to use -feliminate-dwarf2-dups.
5035 * Internationalization
5037 When supported by the host system, GDB will be built with
5038 internationalization (libintl). The task of marking up the sources is
5039 continued, we're looking forward to our first translation.
5043 Initial support for debugging programs compiled with the GNAT
5044 implementation of the Ada programming language has been integrated
5045 into GDB. In this release, support is limited to expression evaluation.
5047 * New native configurations
5049 GNU/Linux/m32r m32r-*-linux-gnu
5053 GDB's remote protocol now includes support for the 'p' packet. This
5054 packet is used to fetch individual registers from a remote inferior.
5056 * END-OF-LIFE registers[] compatibility module
5058 GDB's internal register infrastructure has been completely rewritten.
5059 The new infrastructure making possible the implementation of key new
5060 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5063 GDB 6.3 will be the last release to include the the registers[]
5064 compatibility module that allowed out-of-date configurations to
5065 continue to work. This change directly impacts the following
5075 powerpc bdm protocol
5077 Unless there is activity to revive these configurations, they will be
5078 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5080 * OBSOLETE configurations and files
5082 Configurations that have been declared obsolete in this release have
5083 been commented out. Unless there is activity to revive these
5084 configurations, the next release of GDB will have their sources
5085 permanently REMOVED.
5094 *** Changes in GDB 6.2.1:
5096 * MIPS `break main; run' gave an heuristic-fence-post warning
5098 When attempting to run even a simple program, a warning about
5099 heuristic-fence-post being hit would be reported. This problem has
5102 * MIPS IRIX 'long double' crashed GDB
5104 When examining a long double variable, GDB would get a segmentation
5105 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5106 IRIX long double values).
5110 A bug in the VAX stack code was causing problems with the "next"
5111 command. This problem has been fixed.
5113 *** Changes in GDB 6.2:
5115 * Fix for ``many threads''
5117 On GNU/Linux systems that use the NPTL threads library, a program
5118 rapidly creating and deleting threads would confuse GDB leading to the
5121 ptrace: No such process.
5122 thread_db_get_info: cannot get thread info: generic error
5124 This problem has been fixed.
5126 * "-async" and "-noasync" options removed.
5128 Support for the broken "-noasync" option has been removed (it caused
5131 * New ``start'' command.
5133 This command runs the program until the begining of the main procedure.
5135 * New BSD Kernel Data Access Library (libkvm) interface
5137 Using ``target kvm'' it is now possible to debug kernel core dumps and
5138 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5139 platforms. Currently supported (native-only) configurations are:
5141 FreeBSD/amd64 x86_64-*-freebsd*
5142 FreeBSD/i386 i?86-*-freebsd*
5143 NetBSD/i386 i?86-*-netbsd*
5144 NetBSD/m68k m68*-*-netbsd*
5145 NetBSD/sparc sparc-*-netbsd*
5146 OpenBSD/amd64 x86_64-*-openbsd*
5147 OpenBSD/i386 i?86-*-openbsd*
5148 OpenBSD/m68k m68*-openbsd*
5149 OpenBSD/sparc sparc-*-openbsd*
5151 * Signal trampoline code overhauled
5153 Many generic problems with GDB's signal handling code have been fixed.
5154 These include: backtraces through non-contiguous stacks; recognition
5155 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5156 call; backtrace through a signal trampoline; step into and out of
5157 signal handlers; and single-stepping in the signal trampoline.
5159 Please note that kernel bugs are a limiting factor here. These
5160 features have been shown to work on an s390 GNU/Linux system that
5161 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5163 * Cygwin support for DWARF 2 added.
5165 * New native configurations
5167 GNU/Linux/hppa hppa*-*-linux*
5168 OpenBSD/hppa hppa*-*-openbsd*
5169 OpenBSD/m68k m68*-*-openbsd*
5170 OpenBSD/m88k m88*-*-openbsd*
5171 OpenBSD/powerpc powerpc-*-openbsd*
5172 NetBSD/vax vax-*-netbsd*
5173 OpenBSD/vax vax-*-openbsd*
5175 * END-OF-LIFE frame compatibility module
5177 GDB's internal frame infrastructure has been completely rewritten.
5178 The new infrastructure making it possible to support key new features
5179 including DWARF 2 Call Frame Information. To aid in the task of
5180 migrating old configurations to this new infrastructure, a
5181 compatibility module, that allowed old configurations to continue to
5182 work, was also included.
5184 GDB 6.2 will be the last release to include this frame compatibility
5185 module. This change directly impacts the following configurations:
5195 Unless there is activity to revive these configurations, they will be
5196 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5198 * REMOVED configurations and files
5200 Sun 3, running SunOS 3 m68*-*-sunos3*
5201 Sun 3, running SunOS 4 m68*-*-sunos4*
5202 Sun 2, running SunOS 3 m68000-*-sunos3*
5203 Sun 2, running SunOS 4 m68000-*-sunos4*
5204 Motorola 680x0 running LynxOS m68*-*-lynxos*
5205 AT&T 3b1/Unix pc m68*-att-*
5206 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5207 decstation mips-dec-* mips-little-*
5208 riscos mips-*-riscos* mips-*-sysv*
5209 sonymips mips-sony-*
5210 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5212 *** Changes in GDB 6.1.1:
5214 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5216 The TUI (Text-mode User Interface) is now built as part of a default
5217 GDB configuration. It is enabled by either selecting the TUI with the
5218 command line option "-i=tui" or by running the separate "gdbtui"
5219 program. For more information on the TUI, see the manual "Debugging
5222 * Pending breakpoint support (also included in GDB 6.1)
5224 Support has been added to allow you to specify breakpoints in shared
5225 libraries that have not yet been loaded. If a breakpoint location
5226 cannot be found, and the "breakpoint pending" option is set to auto,
5227 GDB queries you if you wish to make the breakpoint pending on a future
5228 shared-library load. If and when GDB resolves the breakpoint symbol,
5229 the pending breakpoint is removed as one or more regular breakpoints
5232 Pending breakpoints are very useful for GCJ Java debugging.
5234 * Fixed ISO-C build problems
5236 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5237 non ISO-C code that stopped them being built using a more strict ISO-C
5238 compiler (e.g., IBM's C compiler).
5240 * Fixed build problem on IRIX 5
5242 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5243 wasn't able to compile compile on an IRIX 5 system.
5245 * Added execute permission to gdb/gdbserver/configure
5247 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5248 permission. This bug would cause configure to fail on a number of
5249 systems (Solaris, IRIX). Ref: server/519.
5251 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5253 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5254 has been updated to use constant array sizes.
5256 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5258 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5259 its generated DWARF Call Frame Info. This encoding was causing GDB to
5260 panic, that panic has been fixed. Ref: gdb/1628.
5262 * Fixed a problem when examining parameters in shared library code.
5264 When examining parameters in optimized shared library code generated
5265 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5266 not available''. GDB now correctly displays the variable's value.
5268 *** Changes in GDB 6.1:
5270 * Removed --with-mmalloc
5272 Support for the mmalloc memory manager has been removed, as it
5273 conflicted with the internal gdb byte cache.
5275 * Changes in AMD64 configurations
5277 The AMD64 target now includes the %cs and %ss registers. As a result
5278 the AMD64 remote protocol has changed; this affects the floating-point
5279 and SSE registers. If you rely on those registers for your debugging,
5280 you should upgrade gdbserver on the remote side.
5282 * Revised SPARC target
5284 The SPARC target has been completely revised, incorporating the
5285 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5286 support for LynxOS and SunOS 4 has been dropped. Calling functions
5287 from within GDB on operating systems with a non-executable stack
5288 (Solaris, OpenBSD) now works.
5292 GDB has a new C++ demangler which does a better job on the mangled
5293 names generated by current versions of g++. It also runs faster, so
5294 with this and other changes gdb should now start faster on large C++
5297 * DWARF 2 Location Expressions
5299 GDB support for location expressions has been extended to support function
5300 arguments and frame bases. Older versions of GDB could crash when they
5303 * C++ nested types and namespaces
5305 GDB's support for nested types and namespaces in C++ has been
5306 improved, especially if you use the DWARF 2 debugging format. (This
5307 is the default for recent versions of GCC on most platforms.)
5308 Specifically, if you have a class "Inner" defined within a class or
5309 namespace "Outer", then GDB realizes that the class's name is
5310 "Outer::Inner", not simply "Inner". This should greatly reduce the
5311 frequency of complaints about not finding RTTI symbols. In addition,
5312 if you are stopped at inside of a function defined within a namespace,
5313 GDB modifies its name lookup accordingly.
5315 * New native configurations
5317 NetBSD/amd64 x86_64-*-netbsd*
5318 OpenBSD/amd64 x86_64-*-openbsd*
5319 OpenBSD/alpha alpha*-*-openbsd*
5320 OpenBSD/sparc sparc-*-openbsd*
5321 OpenBSD/sparc64 sparc64-*-openbsd*
5323 * New debugging protocols
5325 M32R with SDI protocol m32r-*-elf*
5327 * "set prompt-escape-char" command deleted.
5329 The command "set prompt-escape-char" has been deleted. This command,
5330 and its very obscure effet on GDB's prompt, was never documented,
5331 tested, nor mentioned in the NEWS file.
5333 * OBSOLETE configurations and files
5335 Configurations that have been declared obsolete in this release have
5336 been commented out. Unless there is activity to revive these
5337 configurations, the next release of GDB will have their sources
5338 permanently REMOVED.
5340 Sun 3, running SunOS 3 m68*-*-sunos3*
5341 Sun 3, running SunOS 4 m68*-*-sunos4*
5342 Sun 2, running SunOS 3 m68000-*-sunos3*
5343 Sun 2, running SunOS 4 m68000-*-sunos4*
5344 Motorola 680x0 running LynxOS m68*-*-lynxos*
5345 AT&T 3b1/Unix pc m68*-att-*
5346 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5347 decstation mips-dec-* mips-little-*
5348 riscos mips-*-riscos* mips-*-sysv*
5349 sonymips mips-sony-*
5350 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5352 * REMOVED configurations and files
5354 SGI Irix-4.x mips-sgi-irix4 or iris4
5355 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5356 Z8000 simulator z8k-zilog-none or z8ksim
5357 Matsushita MN10200 w/simulator mn10200-*-*
5358 H8/500 simulator h8500-hitachi-hms or h8500hms
5359 HP/PA running BSD hppa*-*-bsd*
5360 HP/PA running OSF/1 hppa*-*-osf*
5361 HP/PA Pro target hppa*-*-pro*
5362 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5363 386BSD i[3456]86-*-bsd*
5364 Sequent family i[3456]86-sequent-sysv4*
5365 i[3456]86-sequent-sysv*
5366 i[3456]86-sequent-bsd*
5367 SPARC running LynxOS sparc-*-lynxos*
5368 SPARC running SunOS 4 sparc-*-sunos4*
5369 Tsqware Sparclet sparclet-*-*
5370 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5372 *** Changes in GDB 6.0:
5376 Support for debugging the Objective-C programming language has been
5377 integrated into GDB.
5379 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5381 DWARF 2's Call Frame Information makes available compiler generated
5382 information that more exactly describes the program's run-time stack.
5383 By using this information, GDB is able to provide more robust stack
5386 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5387 have been updated to use a new backtrace mechanism which includes
5388 DWARF 2 CFI support.
5392 GDB's remote protocol has been extended to include support for hosted
5393 file I/O (where the remote target uses GDB's file system). See GDB's
5394 remote protocol documentation for details.
5396 * All targets using the new architecture framework.
5398 All of GDB's targets have been updated to use the new internal
5399 architecture framework. The way is now open for future GDB releases
5400 to include cross-architecture native debugging support (i386 on amd64,
5403 * GNU/Linux's Thread Local Storage (TLS)
5405 GDB now includes support for for the GNU/Linux implementation of
5406 per-thread variables.
5408 * GNU/Linux's Native POSIX Thread Library (NPTL)
5410 GDB's thread code has been updated to work with either the new
5411 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5413 * Separate debug info.
5415 GDB, in conjunction with BINUTILS, now supports a mechanism for
5416 automatically loading debug information from a separate file. Instead
5417 of shipping full debug and non-debug versions of system libraries,
5418 system integrators can now instead ship just the stripped libraries
5419 and optional debug files.
5421 * DWARF 2 Location Expressions
5423 DWARF 2 Location Expressions allow the compiler to more completely
5424 describe the location of variables (even in optimized code) to the
5427 GDB now includes preliminary support for location expressions (support
5428 for DW_OP_piece is still missing).
5432 A number of long standing bugs that caused GDB to die while starting a
5433 Java application have been fixed. GDB's Java support is now
5434 considered "useable".
5436 * GNU/Linux support for fork, vfork, and exec.
5438 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5439 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5442 * GDB supports logging output to a file
5444 There are two new commands, "set logging" and "show logging", which can be
5445 used to capture GDB's output to a file.
5447 * The meaning of "detach" has changed for gdbserver
5449 The "detach" command will now resume the application, as documented. To
5450 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5453 * d10v, m68hc11 `regs' command deprecated
5455 The `info registers' command has been updated so that it displays the
5456 registers using a format identical to the old `regs' command.
5460 A new command, "maint set profile on/off", has been added. This command can
5461 be used to enable or disable profiling while running GDB, to profile a
5462 session or a set of commands. In addition there is a new configure switch,
5463 "--enable-profiling", which will cause GDB to be compiled with profiling
5464 data, for more informative profiling results.
5466 * Default MI syntax changed to "mi2".
5468 The default MI (machine interface) syntax, enabled by the command line
5469 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5470 "mi1", can be enabled by specifying the option "-i=mi1".
5472 Support for the original "mi0" syntax (included in GDB 5.0) has been
5475 Fix for gdb/192: removed extraneous space when displaying frame level.
5476 Fix for gdb/672: update changelist is now output in mi list format.
5477 Fix for gdb/702: a -var-assign that updates the value now shows up
5478 in a subsequent -var-update.
5480 * New native configurations.
5482 FreeBSD/amd64 x86_64-*-freebsd*
5484 * Multi-arched targets.
5486 HP/PA HPUX11 hppa*-*-hpux*
5487 Renesas M32R/D w/simulator m32r-*-elf*
5489 * OBSOLETE configurations and files
5491 Configurations that have been declared obsolete in this release have
5492 been commented out. Unless there is activity to revive these
5493 configurations, the next release of GDB will have their sources
5494 permanently REMOVED.
5496 Z8000 simulator z8k-zilog-none or z8ksim
5497 Matsushita MN10200 w/simulator mn10200-*-*
5498 H8/500 simulator h8500-hitachi-hms or h8500hms
5499 HP/PA running BSD hppa*-*-bsd*
5500 HP/PA running OSF/1 hppa*-*-osf*
5501 HP/PA Pro target hppa*-*-pro*
5502 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5503 Sequent family i[3456]86-sequent-sysv4*
5504 i[3456]86-sequent-sysv*
5505 i[3456]86-sequent-bsd*
5506 Tsqware Sparclet sparclet-*-*
5507 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5509 * REMOVED configurations and files
5512 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5513 IBM AIX PS/2 i[3456]86-*-aix
5514 i386 running Mach 3.0 i[3456]86-*-mach3*
5515 i386 running Mach i[3456]86-*-mach*
5516 i386 running OSF/1 i[3456]86-*osf1mk*
5517 HP/Apollo 68k Family m68*-apollo*-sysv*,
5519 m68*-hp-bsd*, m68*-hp-hpux*
5520 Argonaut Risc Chip (ARC) arc-*-*
5521 Mitsubishi D30V d30v-*-*
5522 Fujitsu FR30 fr30-*-elf*
5523 OS/9000 i[34]86-*-os9k
5524 I960 with MON960 i960-*-coff
5526 * MIPS $fp behavior changed
5528 The convenience variable $fp, for the MIPS, now consistently returns
5529 the address of the current frame's base. Previously, depending on the
5530 context, $fp could refer to either $sp or the current frame's base
5531 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5532 The GNU Source-Level Debugger''.
5534 *** Changes in GDB 5.3:
5536 * GNU/Linux shared library multi-threaded performance improved.
5538 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5539 `/proc', in preference to `ptrace' for memory reads. This may result
5540 in an improvement in the start-up time of multi-threaded, shared
5541 library applications when run under GDB. One GDB user writes: ``loads
5542 shared libs like mad''.
5544 * ``gdbserver'' now supports multi-threaded applications on some targets
5546 Support for debugging multi-threaded applications which use
5547 the GNU/Linux LinuxThreads package has been added for
5548 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5549 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5551 * GDB now supports C/C++ preprocessor macros.
5553 GDB now expands preprocessor macro invocations in C/C++ expressions,
5554 and provides various commands for showing macro definitions and how
5557 The new command `macro expand EXPRESSION' expands any macro
5558 invocations in expression, and shows the result.
5560 The new command `show macro MACRO-NAME' shows the definition of the
5561 macro named MACRO-NAME, and where it was defined.
5563 Most compilers don't include information about macros in the debugging
5564 information by default. In GCC 3.1, for example, you need to compile
5565 your program with the options `-gdwarf-2 -g3'. If the macro
5566 information is present in the executable, GDB will read it.
5568 * Multi-arched targets.
5570 DEC Alpha (partial) alpha*-*-*
5571 DEC VAX (partial) vax-*-*
5573 National Semiconductor NS32000 (partial) ns32k-*-*
5574 Motorola 68000 (partial) m68k-*-*
5575 Motorola MCORE mcore-*-*
5579 Fujitsu FRV architecture added by Red Hat frv*-*-*
5582 * New native configurations
5584 Alpha NetBSD alpha*-*-netbsd*
5585 SH NetBSD sh*-*-netbsdelf*
5586 MIPS NetBSD mips*-*-netbsd*
5587 UltraSPARC NetBSD sparc64-*-netbsd*
5589 * OBSOLETE configurations and files
5591 Configurations that have been declared obsolete in this release have
5592 been commented out. Unless there is activity to revive these
5593 configurations, the next release of GDB will have their sources
5594 permanently REMOVED.
5596 Mitsubishi D30V d30v-*-*
5597 OS/9000 i[34]86-*-os9k
5598 IBM AIX PS/2 i[3456]86-*-aix
5599 Fujitsu FR30 fr30-*-elf*
5600 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5601 Argonaut Risc Chip (ARC) arc-*-*
5602 i386 running Mach 3.0 i[3456]86-*-mach3*
5603 i386 running Mach i[3456]86-*-mach*
5604 i386 running OSF/1 i[3456]86-*osf1mk*
5605 HP/Apollo 68k Family m68*-apollo*-sysv*,
5607 m68*-hp-bsd*, m68*-hp-hpux*
5608 I960 with MON960 i960-*-coff
5610 * OBSOLETE languages
5612 CHILL, a Pascal like language used by telecommunications companies.
5614 * REMOVED configurations and files
5616 AMD 29k family via UDI a29k-amd-udi, udi29k
5617 A29K VxWorks a29k-*-vxworks
5618 AMD 29000 embedded, using EBMON a29k-none-none
5619 AMD 29000 embedded with COFF a29k-none-coff
5620 AMD 29000 embedded with a.out a29k-none-aout
5622 testsuite/gdb.hp/gdb.threads-hp/ directory
5624 * New command "set max-user-call-depth <nnn>"
5626 This command allows the user to limit the call depth of user-defined
5627 commands. The default is 1024.
5629 * Changes in FreeBSD/i386 native debugging.
5631 Support for the "generate-core-file" has been added.
5633 * New commands "dump", "append", and "restore".
5635 These commands allow data to be copied from target memory
5636 to a bfd-format or binary file (dump and append), and back
5637 from a file into memory (restore).
5639 * Improved "next/step" support on multi-processor Alpha Tru64.
5641 The previous single-step mechanism could cause unpredictable problems,
5642 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5643 of a software single-step mechanism prevents this.
5645 *** Changes in GDB 5.2.1:
5653 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5654 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5655 Fix, by Joel Brobecker imported from mainline.
5657 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5658 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5659 Fix, by Fred Fish, imported from mainline.
5661 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5662 Surprisingly enough, it works now.
5663 By Michal Ludvig, imported from mainline.
5665 i386 hardware watchpoint support:
5666 avoid misses on second run for some targets.
5667 By Pierre Muller, imported from mainline.
5669 *** Changes in GDB 5.2:
5671 * New command "set trust-readonly-sections on[off]".
5673 This command is a hint that tells gdb that read-only sections
5674 really are read-only (ie. that their contents will not change).
5675 In this mode, gdb will go to the object file rather than the
5676 target to read memory from read-only sections (such as ".text").
5677 This can be a significant performance improvement on some
5678 (notably embedded) targets.
5680 * New command "generate-core-file" (or "gcore").
5682 This new gdb command allows the user to drop a core file of the child
5683 process state at any time. So far it's been implemented only for
5684 GNU/Linux and Solaris, but should be relatively easily ported to other
5685 hosts. Argument is core file name (defaults to core.<pid>).
5687 * New command line option
5689 GDB now accepts --pid or -p followed by a process id.
5691 * Change in command line behavior -- corefiles vs. process ids.
5693 There is a subtle behavior in the way in which GDB handles
5694 command line arguments. The first non-flag argument is always
5695 a program to debug, but the second non-flag argument may either
5696 be a corefile or a process id. Previously, GDB would attempt to
5697 open the second argument as a corefile, and if that failed, would
5698 issue a superfluous error message and then attempt to attach it as
5699 a process. Now, if the second argument begins with a non-digit,
5700 it will be treated as a corefile. If it begins with a digit,
5701 GDB will attempt to attach it as a process, and if no such process
5702 is found, will then attempt to open it as a corefile.
5704 * Changes in ARM configurations.
5706 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5707 configuration is fully multi-arch.
5709 * New native configurations
5711 ARM NetBSD arm*-*-netbsd*
5712 x86 OpenBSD i[3456]86-*-openbsd*
5713 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5714 Sparc64 running FreeBSD sparc64-*-freebsd*
5718 Sanyo XStormy16 xstormy16-elf
5720 * OBSOLETE configurations and files
5722 Configurations that have been declared obsolete in this release have
5723 been commented out. Unless there is activity to revive these
5724 configurations, the next release of GDB will have their sources
5725 permanently REMOVED.
5727 AMD 29k family via UDI a29k-amd-udi, udi29k
5728 A29K VxWorks a29k-*-vxworks
5729 AMD 29000 embedded, using EBMON a29k-none-none
5730 AMD 29000 embedded with COFF a29k-none-coff
5731 AMD 29000 embedded with a.out a29k-none-aout
5733 testsuite/gdb.hp/gdb.threads-hp/ directory
5735 * REMOVED configurations and files
5737 TI TMS320C80 tic80-*-*
5739 PowerPC Solaris powerpcle-*-solaris*
5740 PowerPC Windows NT powerpcle-*-cygwin32
5741 PowerPC Netware powerpc-*-netware*
5742 Harris/CXUX m88k m88*-harris-cxux*
5743 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5744 ns32k-utek-sysv* ns32k-utek-*
5745 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5746 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5747 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5748 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5749 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5751 * Changes to command line processing
5753 The new `--args' feature can be used to specify command-line arguments
5754 for the inferior from gdb's command line.
5756 * Changes to key bindings
5758 There is a new `operate-and-get-next' function bound to `C-o'.
5760 *** Changes in GDB 5.1.1
5762 Fix compile problem on DJGPP.
5764 Fix a problem with floating-point registers on the i386 being
5767 Fix to stop GDB crashing on .debug_str debug info.
5769 Numerous documentation fixes.
5771 Numerous testsuite fixes.
5773 *** Changes in GDB 5.1:
5775 * New native configurations
5777 Alpha FreeBSD alpha*-*-freebsd*
5778 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5779 MIPS GNU/Linux mips*-*-linux*
5780 MIPS SGI Irix 6.x mips*-sgi-irix6*
5781 ia64 AIX ia64-*-aix*
5782 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5786 Motorola 68HC11 and 68HC12 m68hc11-elf
5788 UltraSparc running GNU/Linux sparc64-*-linux*
5790 * OBSOLETE configurations and files
5792 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5793 Harris/CXUX m88k m88*-harris-cxux*
5794 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5795 ns32k-utek-sysv* ns32k-utek-*
5796 TI TMS320C80 tic80-*-*
5798 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5799 PowerPC Solaris powerpcle-*-solaris*
5800 PowerPC Windows NT powerpcle-*-cygwin32
5801 PowerPC Netware powerpc-*-netware*
5802 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5803 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5804 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5805 Apple Macintosh (MPW) host N/A
5807 stuff.c (Program to stuff files into a specially prepared space in kdb)
5808 kdb-start.c (Main loop for the standalone kernel debugger)
5810 Configurations that have been declared obsolete in this release have
5811 been commented out. Unless there is activity to revive these
5812 configurations, the next release of GDB will have their sources
5813 permanently REMOVED.
5815 * REMOVED configurations and files
5817 Altos 3068 m68*-altos-*
5818 Convex c1-*-*, c2-*-*
5820 ARM RISCix arm-*-* (as host)
5824 * GDB has been converted to ISO C.
5826 GDB's source code has been converted to ISO C. In particular, the
5827 sources are fully protoized, and rely on standard headers being
5832 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5834 * The MI enabled by default.
5836 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5837 revised and enabled by default. Packages which use GDB as a debugging
5838 engine behind a UI or another front end are encouraged to switch to
5839 using the GDB/MI interface, instead of the old annotations interface
5840 which is now deprecated.
5842 * Support for debugging Pascal programs.
5844 GDB now includes support for debugging Pascal programs. The following
5845 main features are supported:
5847 - Pascal-specific data types such as sets;
5849 - automatic recognition of Pascal sources based on file-name
5852 - Pascal-style display of data types, variables, and functions;
5854 - a Pascal expression parser.
5856 However, some important features are not yet supported.
5858 - Pascal string operations are not supported at all;
5860 - there are some problems with boolean types;
5862 - Pascal type hexadecimal constants are not supported
5863 because they conflict with the internal variables format;
5865 - support for Pascal objects and classes is not full yet;
5867 - unlike Pascal, GDB is case-sensitive for symbol names.
5869 * Changes in completion.
5871 Commands such as `shell', `run' and `set args', which pass arguments
5872 to inferior programs, now complete on file names, similar to what
5873 users expect at the shell prompt.
5875 Commands which accept locations, such as `disassemble', `print',
5876 `breakpoint', `until', etc. now complete on filenames as well as
5877 program symbols. Thus, if you type "break foob TAB", and the source
5878 files linked into the programs include `foobar.c', that file name will
5879 be one of the candidates for completion. However, file names are not
5880 considered for completion after you typed a colon that delimits a file
5881 name from a name of a function in that file, as in "break foo.c:bar".
5883 `set demangle-style' completes on available demangling styles.
5885 * New platform-independent commands:
5887 It is now possible to define a post-hook for a command as well as a
5888 hook that runs before the command. For more details, see the
5889 documentation of `hookpost' in the GDB manual.
5891 * Changes in GNU/Linux native debugging.
5893 Support for debugging multi-threaded programs has been completely
5894 revised for all platforms except m68k and sparc. You can now debug as
5895 many threads as your system allows you to have.
5897 Attach/detach is supported for multi-threaded programs.
5899 Support for SSE registers was added for x86. This doesn't work for
5900 multi-threaded programs though.
5902 * Changes in MIPS configurations.
5904 Multi-arch support is enabled for all MIPS configurations.
5906 GDB can now be built as native debugger on SGI Irix 6.x systems for
5907 debugging n32 executables. (Debugging 64-bit executables is not yet
5910 * Unified support for hardware watchpoints in all x86 configurations.
5912 Most (if not all) native x86 configurations support hardware-assisted
5913 breakpoints and watchpoints in a unified manner. This support
5914 implements debug register sharing between watchpoints, which allows to
5915 put a virtually infinite number of watchpoints on the same address,
5916 and also supports watching regions up to 16 bytes with several debug
5919 The new maintenance command `maintenance show-debug-regs' toggles
5920 debugging print-outs in functions that insert, remove, and test
5921 watchpoints and hardware breakpoints.
5923 * Changes in the DJGPP native configuration.
5925 New command ``info dos sysinfo'' displays assorted information about
5926 the CPU, OS, memory, and DPMI server.
5928 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5929 display information about segment descriptors stored in GDT, LDT, and
5932 New commands ``info dos pde'' and ``info dos pte'' display entries
5933 from Page Directory and Page Tables (for now works with CWSDPMI only).
5934 New command ``info dos address-pte'' displays the Page Table entry for
5935 a given linear address.
5937 GDB can now pass command lines longer than 126 characters to the
5938 program being debugged (requires an update to the libdbg.a library
5939 which is part of the DJGPP development kit).
5941 DWARF2 debug info is now supported.
5943 It is now possible to `step' and `next' through calls to `longjmp'.
5945 * Changes in documentation.
5947 All GDB documentation was converted to GFDL, the GNU Free
5948 Documentation License.
5950 Tracepoints-related commands are now fully documented in the GDB
5953 TUI, the Text-mode User Interface, is now documented in the manual.
5955 Tracepoints-related commands are now fully documented in the GDB
5958 The "GDB Internals" manual now has an index. It also includes
5959 documentation of `ui_out' functions, GDB coding standards, x86
5960 hardware watchpoints, and memory region attributes.
5962 * GDB's version number moved to ``version.in''
5964 The Makefile variable VERSION has been replaced by the file
5965 ``version.in''. People creating GDB distributions should update the
5966 contents of this file.
5970 GUD support is now a standard part of the EMACS distribution.
5972 *** Changes in GDB 5.0:
5974 * Improved support for debugging FP programs on x86 targets
5976 Unified and much-improved support for debugging floating-point
5977 programs on all x86 targets. In particular, ``info float'' now
5978 displays the FP registers in the same format on all x86 targets, with
5979 greater level of detail.
5981 * Improvements and bugfixes in hardware-assisted watchpoints
5983 It is now possible to watch array elements, struct members, and
5984 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5985 on x86 targets no longer erroneously trigger when the address is
5988 * Improvements in the native DJGPP version of GDB
5990 The distribution now includes all the scripts and auxiliary files
5991 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5992 machines ``out of the box''.
5994 The DJGPP version can now debug programs that use signals. It is
5995 possible to catch signals that happened in the debuggee, deliver
5996 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5997 would kill the program being debugged.) Programs that hook hardware
5998 interrupts (keyboard, timer, etc.) can also be debugged.
6000 It is now possible to debug DJGPP programs that redirect their
6001 standard handles or switch them to raw (as opposed to cooked) mode, or
6002 even close them. The command ``run < foo > bar'' works as expected,
6003 and ``info terminal'' reports useful information about the debuggee's
6004 terminal, including raw/cooked mode, redirection, etc.
6006 The DJGPP version now uses termios functions for console I/O, which
6007 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6010 DOS-style file names with drive letters are now fully supported by
6013 It is now possible to debug DJGPP programs that switch their working
6014 directory. It is also possible to rerun the debuggee any number of
6015 times without restarting GDB; thus, you can use the same setup,
6016 breakpoints, etc. for many debugging sessions.
6018 * New native configurations
6020 ARM GNU/Linux arm*-*-linux*
6021 PowerPC GNU/Linux powerpc-*-linux*
6025 Motorola MCore mcore-*-*
6026 x86 VxWorks i[3456]86-*-vxworks*
6027 PowerPC VxWorks powerpc-*-vxworks*
6028 TI TMS320C80 tic80-*-*
6030 * OBSOLETE configurations
6032 Altos 3068 m68*-altos-*
6033 Convex c1-*-*, c2-*-*
6035 ARM RISCix arm-*-* (as host)
6038 Configurations that have been declared obsolete will be commented out,
6039 but the code will be left in place. If there is no activity to revive
6040 these configurations before the next release of GDB, the sources will
6041 be permanently REMOVED.
6043 * Gould support removed
6045 Support for the Gould PowerNode and NP1 has been removed.
6047 * New features for SVR4
6049 On SVR4 native platforms (such as Solaris), if you attach to a process
6050 without first loading a symbol file, GDB will now attempt to locate and
6051 load symbols from the running process's executable file.
6053 * Many C++ enhancements
6055 C++ support has been greatly improved. Overload resolution now works properly
6056 in almost all cases. RTTI support is on the way.
6058 * Remote targets can connect to a sub-program
6060 A popen(3) style serial-device has been added. This device starts a
6061 sub-process (such as a stand-alone simulator) and then communicates
6062 with that. The sub-program to run is specified using the syntax
6063 ``|<program> <args>'' vis:
6065 (gdb) set remotedebug 1
6066 (gdb) target extended-remote |mn10300-elf-sim program-args
6068 * MIPS 64 remote protocol
6070 A long standing bug in the mips64 remote protocol where by GDB
6071 expected certain 32 bit registers (ex SR) to be transfered as 32
6072 instead of 64 bits has been fixed.
6074 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6075 added to provide backward compatibility with older versions of GDB.
6077 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6079 The command ``set remotebinarydownload'' command has been replaced by
6080 ``set remote X-packet''. Other commands in ``set remote'' family
6081 include ``set remote P-packet''.
6083 * Breakpoint commands accept ranges.
6085 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6086 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6087 ``tracepoint passcount'' also accepts a range of tracepoints.
6089 * ``apropos'' command added.
6091 The ``apropos'' command searches through command names and
6092 documentation strings, printing out matches, making it much easier to
6093 try to find a command that does what you are looking for.
6097 A new machine oriented interface (MI) has been added to GDB. This
6098 interface is designed for debug environments running GDB as a separate
6099 process. This is part of the long term libGDB project. See the
6100 "GDB/MI" chapter of the GDB manual for further information. It can be
6101 enabled by configuring with:
6103 .../configure --enable-gdbmi
6105 *** Changes in GDB-4.18:
6107 * New native configurations
6109 HP-UX 10.20 hppa*-*-hpux10.20
6110 HP-UX 11.x hppa*-*-hpux11.0*
6111 M68K GNU/Linux m68*-*-linux*
6115 Fujitsu FR30 fr30-*-elf*
6116 Intel StrongARM strongarm-*-*
6117 Mitsubishi D30V d30v-*-*
6119 * OBSOLETE configurations
6121 Gould PowerNode, NP1 np1-*-*, pn-*-*
6123 Configurations that have been declared obsolete will be commented out,
6124 but the code will be left in place. If there is no activity to revive
6125 these configurations before the next release of GDB, the sources will
6126 be permanently REMOVED.
6130 As a compatibility experiment, GDB's source files buildsym.h and
6131 buildsym.c have been converted to pure standard C, no longer
6132 containing any K&R compatibility code. We believe that all systems in
6133 use today either come with a standard C compiler, or have a GCC port
6134 available. If this is not true, please report the affected
6135 configuration to bug-gdb@gnu.org immediately. See the README file for
6136 information about getting a standard C compiler if you don't have one
6141 GDB now uses readline 2.2.
6143 * set extension-language
6145 You can now control the mapping between filename extensions and source
6146 languages by using the `set extension-language' command. For instance,
6147 you can ask GDB to treat .c files as C++ by saying
6148 set extension-language .c c++
6149 The command `info extensions' lists all of the recognized extensions
6150 and their associated languages.
6152 * Setting processor type for PowerPC and RS/6000
6154 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6155 you can use the `set processor' command to specify what variant of the
6156 PowerPC family you are debugging. The command
6160 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6161 following PowerPC and RS6000 variants:
6163 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6164 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6166 403GC IBM PowerPC 403GC
6167 505 Motorola PowerPC 505
6168 860 Motorola PowerPC 860 or 850
6169 601 Motorola PowerPC 601
6170 602 Motorola PowerPC 602
6171 603 Motorola/IBM PowerPC 603 or 603e
6172 604 Motorola PowerPC 604 or 604e
6173 750 Motorola/IBM PowerPC 750 or 750
6175 At the moment, this command just tells GDB what to name the
6176 special-purpose processor registers. Since almost all the affected
6177 registers are inaccessible to user-level programs, this command is
6178 only useful for remote debugging in its present form.
6182 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6183 more extensive support for HP-UX. Added features include shared
6184 library support, kernel threads and hardware watchpoints for 11.00,
6185 support for HP's ANSI C and C++ compilers, and a compatibility mode
6186 for xdb and dbx commands.
6190 HP's donation includes the new concept of catchpoints, which is a
6191 generalization of the old catch command. On HP-UX, it is now possible
6192 to catch exec, fork, and vfork, as well as library loading.
6194 This means that the existing catch command has changed; its first
6195 argument now specifies the type of catch to be set up. See the
6196 output of "help catch" for a list of catchpoint types.
6198 * Debugging across forks
6200 On HP-UX, you can choose which process to debug when a fork() happens
6205 HP has donated a curses-based terminal user interface (TUI). To get
6206 it, build with --enable-tui. Although this can be enabled for any
6207 configuration, at present it only works for native HP debugging.
6209 * GDB remote protocol additions
6211 A new protocol packet 'X' that writes binary data is now available.
6212 Default behavior is to try 'X', then drop back to 'M' if the stub
6213 fails to respond. The settable variable `remotebinarydownload'
6214 allows explicit control over the use of 'X'.
6216 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6217 full 64-bit address. The command
6219 set remoteaddresssize 32
6221 can be used to revert to the old behaviour. For existing remote stubs
6222 the change should not be noticed, as the additional address information
6225 In order to assist in debugging stubs, you may use the maintenance
6226 command `packet' to send any text string to the stub. For instance,
6228 maint packet heythere
6230 sends the packet "$heythere#<checksum>". Note that it is very easy to
6231 disrupt a debugging session by sending the wrong packet at the wrong
6234 The compare-sections command allows you to compare section data on the
6235 target to what is in the executable file without uploading or
6236 downloading, by comparing CRC checksums.
6238 * Tracing can collect general expressions
6240 You may now collect general expressions at tracepoints. This requires
6241 further additions to the target-side stub; see tracepoint.c and
6242 doc/agentexpr.texi for further details.
6244 * mask-address variable for Mips
6246 For Mips targets, you may control the zeroing of the upper 32 bits of
6247 a 64-bit address by entering `set mask-address on'. This is mainly
6248 of interest to users of embedded R4xxx and R5xxx processors.
6250 * Higher serial baud rates
6252 GDB's serial code now allows you to specify baud rates 57600, 115200,
6253 230400, and 460800 baud. (Note that your host system may not be able
6254 to achieve all of these rates.)
6258 The i960 configuration now includes an initial implementation of a
6259 builtin simulator, contributed by Jim Wilson.
6262 *** Changes in GDB-4.17:
6264 * New native configurations
6266 Alpha GNU/Linux alpha*-*-linux*
6267 Unixware 2.x i[3456]86-unixware2*
6268 Irix 6.x mips*-sgi-irix6*
6269 PowerPC GNU/Linux powerpc-*-linux*
6270 PowerPC Solaris powerpcle-*-solaris*
6271 Sparc GNU/Linux sparc-*-linux*
6272 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6276 Argonaut Risc Chip (ARC) arc-*-*
6277 Hitachi H8/300S h8300*-*-*
6278 Matsushita MN10200 w/simulator mn10200-*-*
6279 Matsushita MN10300 w/simulator mn10300-*-*
6280 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6281 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6282 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6283 Mitsubishi D10V w/simulator d10v-*-*
6284 Mitsubishi M32R/D w/simulator m32r-*-elf*
6285 Tsqware Sparclet sparclet-*-*
6286 NEC V850 w/simulator v850-*-*
6288 * New debugging protocols
6290 ARM with RDI protocol arm*-*-*
6291 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6292 DDB and LSI variants of PMON protocol mips*-*-*
6293 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6294 PowerPC with SDS protocol powerpc{,le}-*-eabi
6295 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6299 All configurations can now understand and use the DWARF 2 debugging
6300 format. The choice is automatic, if the symbol file contains DWARF 2
6305 GDB now includes basic Java language support. This support is
6306 only useful with Java compilers that produce native machine code.
6308 * solib-absolute-prefix and solib-search-path
6310 For SunOS and SVR4 shared libraries, you may now set the prefix for
6311 loading absolute shared library symbol files, and the search path for
6312 locating non-absolute shared library symbol files.
6314 * Live range splitting
6316 GDB can now effectively debug code for which GCC has performed live
6317 range splitting as part of its optimization. See gdb/doc/LRS for
6318 more details on the expected format of the stabs information.
6322 GDB's support for the GNU Hurd, including thread debugging, has been
6323 updated to work with current versions of the Hurd.
6327 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6328 instruction set. ARM GDB automatically detects when Thumb
6329 instructions are in use, and adjusts disassembly and backtracing
6334 GDB's MIPS target configurations now handle the MIP16 16-bit
6339 GDB now includes support for overlays; if an executable has been
6340 linked such that multiple sections are based at the same address, GDB
6341 will decide which section to use for symbolic info. You can choose to
6342 control the decision manually, using overlay commands, or implement
6343 additional target-side support and use "overlay load-target" to bring
6344 in the overlay mapping. Do "help overlay" for more detail.
6348 The command "info symbol <address>" displays information about
6349 the symbol at the specified address.
6353 The standard remote protocol now includes an extension that allows
6354 asynchronous collection and display of trace data. This requires
6355 extensive support in the target-side debugging stub. Tracing mode
6356 includes a new interaction mode in GDB and new commands: see the
6357 file tracepoint.c for more details.
6361 Configurations for embedded MIPS now include a simulator contributed
6362 by Cygnus Solutions. The simulator supports the instruction sets
6363 of most MIPS variants.
6367 Sparc configurations may now include the ERC32 simulator contributed
6368 by the European Space Agency. The simulator is not built into
6369 Sparc targets by default; configure with --enable-sim to include it.
6373 For target configurations that may include multiple variants of a
6374 basic architecture (such as MIPS and SH), you may now set the
6375 architecture explicitly. "set arch" sets, "info arch" lists
6376 the possible architectures.
6378 *** Changes in GDB-4.16:
6380 * New native configurations
6382 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6383 M68K NetBSD m68k-*-netbsd*
6384 PowerPC AIX 4.x powerpc-*-aix*
6385 PowerPC MacOS powerpc-*-macos*
6386 PowerPC Windows NT powerpcle-*-cygwin32
6387 RS/6000 AIX 4.x rs6000-*-aix4*
6391 ARM with RDP protocol arm-*-*
6392 I960 with MON960 i960-*-coff
6393 MIPS VxWorks mips*-*-vxworks*
6394 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6395 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6397 Matra Sparclet sparclet-*-*
6401 The powerpc-eabi configuration now includes the PSIM simulator,
6402 contributed by Andrew Cagney, with assistance from Mike Meissner.
6403 PSIM is a very elaborate model of the PowerPC, including not only
6404 basic instruction set execution, but also details of execution unit
6405 performance and I/O hardware. See sim/ppc/README for more details.
6409 GDB now works with Solaris 2.5.
6411 * Windows 95/NT native
6413 GDB will now work as a native debugger on Windows 95 and Windows NT.
6414 To build it from source, you must use the "gnu-win32" environment,
6415 which uses a DLL to emulate enough of Unix to run the GNU tools.
6416 Further information, binaries, and sources are available at
6417 ftp.cygnus.com, under pub/gnu-win32.
6419 * dont-repeat command
6421 If a user-defined command includes the command `dont-repeat', then the
6422 command will not be repeated if the user just types return. This is
6423 useful if the command is time-consuming to run, so that accidental
6424 extra keystrokes don't run the same command many times.
6426 * Send break instead of ^C
6428 The standard remote protocol now includes an option to send a break
6429 rather than a ^C to the target in order to interrupt it. By default,
6430 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6432 * Remote protocol timeout
6434 The standard remote protocol includes a new variable `remotetimeout'
6435 that allows you to set the number of seconds before GDB gives up trying
6436 to read from the target. The default value is 2.
6438 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6440 By default GDB will automatically keep track of objects as they are
6441 loaded and unloaded by the dynamic linker. By using the command `set
6442 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6443 when shared library events occur, thus allowing you to set breakpoints
6444 in shared libraries which are explicitly loaded by the inferior.
6446 Note this feature does not work on hpux8. On hpux9 you must link
6447 /usr/lib/end.o into your program. This feature should work
6448 automatically on hpux10.
6450 * Irix 5.x hardware watchpoint support
6452 Irix 5 configurations now support the use of hardware watchpoints.
6454 * Mips protocol "SYN garbage limit"
6456 When debugging a Mips target using the `target mips' protocol, you
6457 may set the number of characters that GDB will ignore by setting
6458 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6459 every character. The default value is 1050.
6461 * Recording and replaying remote debug sessions
6463 If you set `remotelogfile' to the name of a file, gdb will write to it
6464 a recording of a remote debug session. This recording may then be
6465 replayed back to gdb using "gdbreplay". See gdbserver/README for
6466 details. This is useful when you have a problem with GDB while doing
6467 remote debugging; you can make a recording of the session and send it
6468 to someone else, who can then recreate the problem.
6470 * Speedups for remote debugging
6472 GDB includes speedups for downloading and stepping MIPS systems using
6473 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6474 and more efficient S-record downloading.
6476 * Memory use reductions and statistics collection
6478 GDB now uses less memory and reports statistics about memory usage.
6479 Try the `maint print statistics' command, for example.
6481 *** Changes in GDB-4.15:
6483 * Psymtabs for XCOFF
6485 The symbol reader for AIX GDB now uses partial symbol tables. This
6486 can greatly improve startup time, especially for large executables.
6488 * Remote targets use caching
6490 Remote targets now use a data cache to speed up communication with the
6491 remote side. The data cache could lead to incorrect results because
6492 it doesn't know about volatile variables, thus making it impossible to
6493 debug targets which use memory mapped I/O devices. `set remotecache
6494 off' turns the the data cache off.
6496 * Remote targets may have threads
6498 The standard remote protocol now includes support for multiple threads
6499 in the target system, using new protocol commands 'H' and 'T'. See
6500 gdb/remote.c for details.
6504 If GDB is configured with `--enable-netrom', then it will include
6505 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6506 acts as though it is a bank of ROM on the target board, but you can
6507 write into it over the network. GDB's support consists only of
6508 support for fast loading into the emulated ROM; to debug, you must use
6509 another protocol, such as standard remote protocol. The usual
6510 sequence is something like
6512 target nrom <netrom-hostname>
6514 target remote <netrom-hostname>:1235
6518 GDB now includes support for the Apple Macintosh, as a host only. It
6519 may be run as either an MPW tool or as a standalone application, and
6520 it can debug through the serial port. All the usual GDB commands are
6521 available, but to the target command, you must supply "serial" as the
6522 device type instead of "/dev/ttyXX". See mpw-README in the main
6523 directory for more information on how to build. The MPW configuration
6524 scripts */mpw-config.in support only a few targets, and only the
6525 mips-idt-ecoff target has been tested.
6529 GDB configuration now uses autoconf. This is not user-visible,
6530 but does simplify configuration and building.
6534 GDB now supports hpux10.
6536 *** Changes in GDB-4.14:
6538 * New native configurations
6540 x86 FreeBSD i[345]86-*-freebsd
6541 x86 NetBSD i[345]86-*-netbsd
6542 NS32k NetBSD ns32k-*-netbsd
6543 Sparc NetBSD sparc-*-netbsd
6547 A29K VxWorks a29k-*-vxworks
6548 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6549 CPU32 EST-300 emulator m68*-*-est*
6550 PowerPC ELF powerpc-*-elf
6553 * Alpha OSF/1 support for procfs
6555 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6556 possible to attach to running processes. As the mounting of the /proc
6557 filesystem is optional on the Alpha, GDB automatically determines
6558 the availability of /proc during startup. This can lead to problems
6559 if /proc is unmounted after GDB has been started.
6561 * Arguments to user-defined commands
6563 User commands may accept up to 10 arguments separated by whitespace.
6564 Arguments are accessed within the user command via $arg0..$arg9. A
6567 print $arg0 + $arg1 + $arg2
6569 To execute the command use:
6572 Defines the command "adder" which prints the sum of its three arguments.
6573 Note the arguments are text substitutions, so they may reference variables,
6574 use complex expressions, or even perform inferior function calls.
6576 * New `if' and `while' commands
6578 This makes it possible to write more sophisticated user-defined
6579 commands. Both commands take a single argument, which is the
6580 expression to evaluate, and must be followed by the commands to
6581 execute, one per line, if the expression is nonzero, the list being
6582 terminated by the word `end'. The `if' command list may include an
6583 `else' word, which causes the following commands to be executed only
6584 if the expression is zero.
6586 * Fortran source language mode
6588 GDB now includes partial support for Fortran 77. It will recognize
6589 Fortran programs and can evaluate a subset of Fortran expressions, but
6590 variables and functions may not be handled correctly. GDB will work
6591 with G77, but does not yet know much about symbols emitted by other
6594 * Better HPUX support
6596 Most debugging facilities now work on dynamic executables for HPPAs
6597 running hpux9 or later. You can attach to running dynamically linked
6598 processes, but by default the dynamic libraries will be read-only, so
6599 for instance you won't be able to put breakpoints in them. To change
6600 that behavior do the following before running the program:
6606 This will cause the libraries to be mapped private and read-write.
6607 To revert to the normal behavior, do this:
6613 You cannot set breakpoints or examine data in the library until after
6614 the library is loaded if the function/data symbols do not have
6617 GDB can now also read debug symbols produced by the HP C compiler on
6618 HPPAs (sorry, no C++, Fortran or 68k support).
6620 * Target byte order now dynamically selectable
6622 You can choose which byte order to use with a target system, via the
6623 commands "set endian big" and "set endian little", and you can see the
6624 current setting by using "show endian". You can also give the command
6625 "set endian auto", in which case GDB will use the byte order
6626 associated with the executable. Currently, only embedded MIPS
6627 configurations support dynamic selection of target byte order.
6629 * New DOS host serial code
6631 This version uses DPMI interrupts to handle buffered I/O, so you
6632 no longer need to run asynctsr when debugging boards connected to
6635 *** Changes in GDB-4.13:
6637 * New "complete" command
6639 This lists all the possible completions for the rest of the line, if it
6640 were to be given as a command itself. This is intended for use by emacs.
6642 * Trailing space optional in prompt
6644 "set prompt" no longer adds a space for you after the prompt you set. This
6645 allows you to set a prompt which ends in a space or one that does not.
6647 * Breakpoint hit counts
6649 "info break" now displays a count of the number of times the breakpoint
6650 has been hit. This is especially useful in conjunction with "ignore"; you
6651 can ignore a large number of breakpoint hits, look at the breakpoint info
6652 to see how many times the breakpoint was hit, then run again, ignoring one
6653 less than that number, and this will get you quickly to the last hit of
6656 * Ability to stop printing at NULL character
6658 "set print null-stop" will cause GDB to stop printing the characters of
6659 an array when the first NULL is encountered. This is useful when large
6660 arrays actually contain only short strings.
6662 * Shared library breakpoints
6664 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6665 breakpoints in shared libraries before the executable is run.
6667 * Hardware watchpoints
6669 There is a new hardware breakpoint for the watch command for sparclite
6670 targets. See gdb/sparclite/hw_breakpoint.note.
6672 Hardware watchpoints are also now supported under GNU/Linux.
6676 Annotations have been added. These are for use with graphical interfaces,
6677 and are still experimental. Currently only gdba.el uses these.
6679 * Improved Irix 5 support
6681 GDB now works properly with Irix 5.2.
6683 * Improved HPPA support
6685 GDB now works properly with the latest GCC and GAS.
6687 * New native configurations
6689 Sequent PTX4 i[34]86-sequent-ptx4
6690 HPPA running OSF/1 hppa*-*-osf*
6691 Atari TT running SVR4 m68*-*-sysv4*
6692 RS/6000 LynxOS rs6000-*-lynxos*
6696 OS/9000 i[34]86-*-os9k
6697 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6700 * Hitachi SH7000 and E7000-PC ICE support
6702 There is now support for communicating with the Hitachi E7000-PC ICE.
6703 This is available automatically when GDB is configured for the SH.
6707 As usual, a variety of small fixes and improvements, both generic
6708 and configuration-specific. See the ChangeLog for more detail.
6710 *** Changes in GDB-4.12:
6712 * Irix 5 is now supported
6716 GDB-4.12 on the HPPA has a number of changes which make it unable
6717 to debug the output from the currently released versions of GCC and
6718 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6719 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6720 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6723 *** Changes in GDB-4.11:
6725 * User visible changes:
6729 The "set remotedebug" option is now consistent between the mips remote
6730 target, remote targets using the gdb-specific protocol, UDI (AMD's
6731 debug protocol for the 29k) and the 88k bug monitor. It is now an
6732 integer specifying a debug level (normally 0 or 1, but 2 means more
6733 debugging info for the mips target).
6735 * DEC Alpha native support
6737 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6738 debug info, but GDB works fairly well with the DEC compiler and should
6739 work with a future GCC release. See the README file for a few
6740 Alpha-specific notes.
6742 * Preliminary thread implementation
6744 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6746 * LynxOS native and target support for 386
6748 This release has been hosted on LynxOS 2.2, and also can be configured
6749 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6752 * Improvements in C++ mangling/demangling.
6754 This release has much better g++ debugging, specifically in name
6755 mangling/demangling, virtual function calls, print virtual table,
6756 call methods, ...etc.
6758 *** Changes in GDB-4.10:
6760 * User visible changes:
6762 Remote debugging using the GDB-specific (`target remote') protocol now
6763 supports the `load' command. This is only useful if you have some
6764 other way of getting the stub to the target system, and you can put it
6765 somewhere in memory where it won't get clobbered by the download.
6767 Filename completion now works.
6769 When run under emacs mode, the "info line" command now causes the
6770 arrow to point to the line specified. Also, "info line" prints
6771 addresses in symbolic form (as well as hex).
6773 All vxworks based targets now support a user settable option, called
6774 vxworks-timeout. This option represents the number of seconds gdb
6775 should wait for responses to rpc's. You might want to use this if
6776 your vxworks target is, perhaps, a slow software simulator or happens
6777 to be on the far side of a thin network line.
6781 This release contains support for using a DEC alpha as a GDB host for
6782 cross debugging. Native alpha debugging is not supported yet.
6785 *** Changes in GDB-4.9:
6789 This is the first GDB release which is accompanied by a matching testsuite.
6790 The testsuite requires installation of dejagnu, which should be available
6791 via ftp from most sites that carry GNU software.
6795 'Cfront' style demangling has had its name changed to 'ARM' style, to
6796 emphasize that it was written from the specifications in the C++ Annotated
6797 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6798 disclaimers, it still generated too much confusion with users attempting to
6799 use gdb with AT&T cfront.
6803 GDB now uses a standard remote interface to a simulator library.
6804 So far, the library contains simulators for the Zilog Z8001/2, the
6805 Hitachi H8/300, H8/500 and Super-H.
6807 * New targets supported
6809 H8/300 simulator h8300-hitachi-hms or h8300hms
6810 H8/500 simulator h8500-hitachi-hms or h8500hms
6811 SH simulator sh-hitachi-hms or sh
6812 Z8000 simulator z8k-zilog-none or z8ksim
6813 IDT MIPS board over serial line mips-idt-ecoff
6815 Cross-debugging to GO32 targets is supported. It requires a custom
6816 version of the i386-stub.c module which is integrated with the
6817 GO32 memory extender.
6819 * New remote protocols
6821 MIPS remote debugging protocol.
6823 * New source languages supported
6825 This version includes preliminary support for Chill, a Pascal like language
6826 used by telecommunications companies. Chill support is also being integrated
6827 into the GNU compiler, but we don't know when it will be publically available.
6830 *** Changes in GDB-4.8:
6832 * HP Precision Architecture supported
6834 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6835 version of this support was available as a set of patches from the
6836 University of Utah. GDB does not support debugging of programs
6837 compiled with the HP compiler, because HP will not document their file
6838 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6839 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6841 Many problems in the preliminary version have been fixed.
6843 * Faster and better demangling
6845 We have improved template demangling and fixed numerous bugs in the GNU style
6846 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6847 character types (wchar_t) are now supported. Demangling of each symbol is now
6848 only done once, and is cached when the symbol table for a file is read in.
6849 This results in a small increase in memory usage for C programs, a moderate
6850 increase in memory usage for C++ programs, and a fantastic speedup in
6853 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6854 from the specifications in the Annotated Reference Manual, which AT&T's
6855 compiler does not actually implement.
6857 * G++ multiple inheritance compiler problem
6859 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6860 inheritance lattices was reworked to properly discover ambiguities. We
6861 recently found an example which causes this new algorithm to fail in a
6862 very subtle way, producing bad debug information for those classes.
6863 The file 'gcc.patch' (in this directory) can be applied to gcc to
6864 circumvent the problem. A future GCC release will contain a complete
6867 The previous G++ debug info problem (mentioned below for the gdb-4.7
6868 release) is fixed in gcc version 2.3.2.
6870 * Improved configure script
6872 The `configure' script will now attempt to guess your system type if
6873 you don't supply a host system type. The old scheme of supplying a
6874 host system triplet is preferable over using this. All the magic is
6875 done in the new `config.guess' script. Examine it for details.
6877 We have also brought our configure script much more in line with the FSF's
6878 version. It now supports the --with-xxx options. In particular,
6879 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6880 The resulting GDB will not be able to read arbitrary object file formats --
6881 only the format ``expected'' to be used on the configured target system.
6882 We hope to make this the default in a future release.
6884 * Documentation improvements
6886 There's new internal documentation on how to modify GDB, and how to
6887 produce clean changes to the code. We implore people to read it
6888 before submitting changes.
6890 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6891 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6892 `info' files are also provided. To build `info' files from scratch,
6893 you will need the latest `makeinfo' release, which will be available in
6894 a future texinfo-X.Y release.
6896 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6897 We're not sure exactly which versions have this problem, but it has
6898 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6899 or better. If that isn't possible, there is a patch in
6900 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6901 around this problem.
6905 GDB now supports array constants that can be used in expressions typed in by
6906 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6907 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6910 The new directory `gdb/sparclite' contains a program that demonstrates
6911 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6913 * New native hosts supported
6915 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6916 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6918 * New targets supported
6920 AMD 29k family via UDI a29k-amd-udi or udi29k
6922 * New file formats supported
6924 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6925 HPUX core files, and SCO 3.2v2 core files.
6929 Attaching to processes now works again; thanks for the many bug reports.
6931 We have also stomped on a bunch of core dumps caused by
6932 printf_filtered("%s") problems.
6934 We eliminated a copyright problem on the rpc and ptrace header files
6935 for VxWorks, which was discovered at the last minute during the 4.7
6936 release. You should now be able to build a VxWorks GDB.
6938 You can now interrupt gdb while an attached process is running. This
6939 will cause the attached process to stop, and give control back to GDB.
6941 We fixed problems caused by using too many file descriptors
6942 for reading symbols from object files and libraries. This was
6943 especially a problem for programs that used many (~100) shared
6946 The `step' command now only enters a subroutine if there is line number
6947 information for the subroutine. Otherwise it acts like the `next'
6948 command. Previously, `step' would enter subroutines if there was
6949 any debugging information about the routine. This avoids problems
6950 when using `cc -g1' on MIPS machines.
6952 * Internal improvements
6954 GDB's internal interfaces have been improved to make it easier to support
6955 debugging of multiple languages in the future.
6957 GDB now uses a common structure for symbol information internally.
6958 Minimal symbols (derived from linkage symbols in object files), partial
6959 symbols (from a quick scan of debug information), and full symbols
6960 contain a common subset of information, making it easier to write
6961 shared code that handles any of them.
6963 * New command line options
6965 We now accept --silent as an alias for --quiet.
6969 The memory-mapped-malloc library is now licensed under the GNU Library
6970 General Public License.
6972 *** Changes in GDB-4.7:
6974 * Host/native/target split
6976 GDB has had some major internal surgery to untangle the support for
6977 hosts and remote targets. Now, when you configure GDB for a remote
6978 target, it will no longer load in all of the support for debugging
6979 local programs on the host. When fully completed and tested, this will
6980 ensure that arbitrary host/target combinations are possible.
6982 The primary conceptual shift is to separate the non-portable code in
6983 GDB into three categories. Host specific code is required any time GDB
6984 is compiled on that host, regardless of the target. Target specific
6985 code relates to the peculiarities of the target, but can be compiled on
6986 any host. Native specific code is everything else: it can only be
6987 built when the host and target are the same system. Child process
6988 handling and core file support are two common `native' examples.
6990 GDB's use of /proc for controlling Unix child processes is now cleaner.
6991 It has been split out into a single module under the `target_ops' vector,
6992 plus two native-dependent functions for each system that uses /proc.
6994 * New hosts supported
6996 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6997 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6998 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7000 * New targets supported
7002 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7003 68030 and CPU32 m68030-*-*, m68332-*-*
7005 * New native hosts supported
7007 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7008 (386bsd is not well tested yet)
7009 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7011 * New file formats supported
7013 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7014 supports reading of `a.out.adobe' object files, which are an a.out
7015 format extended with minimal information about multiple sections.
7019 `show copying' is the same as the old `info copying'.
7020 `show warranty' is the same as `info warrantee'.
7021 These were renamed for consistency. The old commands continue to work.
7023 `info handle' is a new alias for `info signals'.
7025 You can now define pre-command hooks, which attach arbitrary command
7026 scripts to any command. The commands in the hook will be executed
7027 prior to the user's command. You can also create a hook which will be
7028 executed whenever the program stops. See gdb.texinfo.
7032 We now deal with Cfront style name mangling, and can even extract type
7033 info from mangled symbols. GDB can automatically figure out which
7034 symbol mangling style your C++ compiler uses.
7036 Calling of methods and virtual functions has been improved as well.
7040 The crash that occured when debugging Sun Ansi-C compiled binaries is
7041 fixed. This was due to mishandling of the extra N_SO stabs output
7044 We also finally got Ultrix 4.2 running in house, and fixed core file
7045 support, with help from a dozen people on the net.
7047 John M. Farrell discovered that the reason that single-stepping was so
7048 slow on all of the Mips based platforms (primarily SGI and DEC) was
7049 that we were trying to demangle and lookup a symbol used for internal
7050 purposes on every instruction that was being stepped through. Changing
7051 the name of that symbol so that it couldn't be mistaken for a C++
7052 mangled symbol sped things up a great deal.
7054 Rich Pixley sped up symbol lookups in general by getting much smarter
7055 about when C++ symbol mangling is necessary. This should make symbol
7056 completion (TAB on the command line) much faster. It's not as fast as
7057 we'd like, but it's significantly faster than gdb-4.6.
7061 A new user controllable variable 'call_scratch_address' can
7062 specify the location of a scratch area to be used when GDB
7063 calls a function in the target. This is necessary because the
7064 usual method of putting the scratch area on the stack does not work
7065 in systems that have separate instruction and data spaces.
7067 We integrated changes to support the 29k UDI (Universal Debugger
7068 Interface), but discovered at the last minute that we didn't have all
7069 of the appropriate copyright paperwork. We are working with AMD to
7070 resolve this, and hope to have it available soon.
7074 We have sped up the remote serial line protocol, especially for targets
7075 with lots of registers. It now supports a new `expedited status' ('T')
7076 message which can be used in place of the existing 'S' status message.
7077 This allows the remote stub to send only the registers that GDB
7078 needs to make a quick decision about single-stepping or conditional
7079 breakpoints, eliminating the need to fetch the entire register set for
7080 each instruction being stepped through.
7082 The GDB remote serial protocol now implements a write-through cache for
7083 registers, only re-reading the registers if the target has run.
7085 There is also a new remote serial stub for SPARC processors. You can
7086 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7087 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7088 processor with a serial port.
7092 Configure.in files have become much easier to read and modify. A new
7093 `table driven' format makes it more obvious what configurations are
7094 supported, and what files each one uses.
7098 There is a new opcodes library which will eventually contain all of the
7099 disassembly routines and opcode tables. At present, it only contains
7100 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7101 disassembler (binutils/objdump) to share these routines.
7103 The libiberty library is now copylefted under the GNU Library General
7104 Public License. This allows more liberal use, and was done so libg++
7105 can use it. This makes no difference to GDB, since the Library License
7106 grants all the rights from the General Public License.
7110 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7111 reference to the stabs symbol info used by the debugger. It is (as far
7112 as we know) the only published document on this fascinating topic. We
7113 encourage you to read it, compare it to the stabs information on your
7114 system, and send improvements on the document in general (to
7115 bug-gdb@prep.ai.mit.edu).
7117 And, of course, many bugs have been fixed.
7120 *** Changes in GDB-4.6:
7122 * Better support for C++ function names
7124 GDB now accepts as input the "demangled form" of C++ overloaded function
7125 names and member function names, and can do command completion on such names
7126 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7127 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7128 Make use of command completion, it is your friend.
7130 GDB also now accepts a variety of C++ mangled symbol formats. They are
7131 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7132 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7133 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7134 for the list of formats.
7136 * G++ symbol mangling problem
7138 Recent versions of gcc have a bug in how they emit debugging information for
7139 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7140 directory) can be applied to gcc to fix the problem. Alternatively, if you
7141 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7142 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7143 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7146 * New 'maintenance' command
7148 All of the commands related to hacking GDB internals have been moved out of
7149 the main command set, and now live behind the 'maintenance' command. This
7150 can also be abbreviated as 'mt'. The following changes were made:
7152 dump-me -> maintenance dump-me
7153 info all-breakpoints -> maintenance info breakpoints
7154 printmsyms -> maintenance print msyms
7155 printobjfiles -> maintenance print objfiles
7156 printpsyms -> maintenance print psymbols
7157 printsyms -> maintenance print symbols
7159 The following commands are new:
7161 maintenance demangle Call internal GDB demangler routine to
7162 demangle a C++ link name and prints the result.
7163 maintenance print type Print a type chain for a given symbol
7165 * Change to .gdbinit file processing
7167 We now read the $HOME/.gdbinit file before processing the argv arguments
7168 (e.g. reading symbol files or core files). This allows global parameters to
7169 be set, which will apply during the symbol reading. The ./.gdbinit is still
7170 read after argv processing.
7172 * New hosts supported
7174 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7176 GNU/Linux support i386-unknown-linux or linux
7178 We are also including code to support the HP/PA running BSD and HPUX. This
7179 is almost guaranteed not to work, as we didn't have time to test or build it
7180 for this release. We are including it so that the more adventurous (or
7181 masochistic) of you can play with it. We also had major problems with the
7182 fact that the compiler that we got from HP doesn't support the -g option.
7185 * New targets supported
7187 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7189 * More smarts about finding #include files
7191 GDB now remembers the compilation directory for all include files, and for
7192 all files from which C is generated (like yacc and lex sources). This
7193 greatly improves GDB's ability to find yacc/lex sources, and include files,
7194 especially if you are debugging your program from a directory different from
7195 the one that contains your sources.
7197 We also fixed a bug which caused difficulty with listing and setting
7198 breakpoints in include files which contain C code. (In the past, you had to
7199 try twice in order to list an include file that you hadn't looked at before.)
7201 * Interesting infernals change
7203 GDB now deals with arbitrary numbers of sections, where the symbols for each
7204 section must be relocated relative to that section's landing place in the
7205 target's address space. This work was needed to support ELF with embedded
7206 stabs used by Solaris-2.0.
7208 * Bug fixes (of course!)
7210 There have been loads of fixes for the following things:
7211 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7212 i960, stabs, DOS(GO32), procfs, etc...
7214 See the ChangeLog for details.
7216 *** Changes in GDB-4.5:
7218 * New machines supported (host and target)
7220 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7222 SGI Irix-4.x mips-sgi-irix4 or iris4
7224 * New malloc package
7226 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7227 Mmalloc is capable of handling mutiple heaps of memory. It is also
7228 capable of saving a heap to a file, and then mapping it back in later.
7229 This can be used to greatly speedup the startup of GDB by using a
7230 pre-parsed symbol table which lives in a mmalloc managed heap. For
7231 more details, please read mmalloc/mmalloc.texi.
7235 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7236 'help info proc' for details.
7238 * MIPS ecoff symbol table format
7240 The code that reads MIPS symbol table format is now supported on all hosts.
7241 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7244 * File name changes for MS-DOS
7246 Many files in the config directories have been renamed to make it easier to
7247 support GDB on MS-DOSe systems (which have very restrictive file name
7248 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7249 environment) is close to working but has some remaining problems. Note
7250 that debugging of DOS programs is not supported, due to limitations
7251 in the ``operating system'', but it can be used to host cross-debugging.
7253 * Cross byte order fixes
7255 Many fixes have been made to support cross debugging of Sparc and MIPS
7256 targets from hosts whose byte order differs.
7258 * New -mapped and -readnow options
7260 If memory-mapped files are available on your system through the 'mmap'
7261 system call, you can use the -mapped option on the `file' or
7262 `symbol-file' commands to cause GDB to write the symbols from your
7263 program into a reusable file. If the program you are debugging is
7264 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7265 Future GDB debugging sessions will notice the presence of this file,
7266 and will quickly map in symbol information from it, rather than reading
7267 the symbol table from the executable program. Using the '-mapped'
7268 option in a GDB `file' or `symbol-file' command has the same effect as
7269 starting GDB with the '-mapped' command-line option.
7271 You can cause GDB to read the entire symbol table immediately by using
7272 the '-readnow' option with any of the commands that load symbol table
7273 information (or on the GDB command line). This makes the command
7274 slower, but makes future operations faster.
7276 The -mapped and -readnow options are typically combined in order to
7277 build a `fred.syms' file that contains complete symbol information.
7278 A simple GDB invocation to do nothing but build a `.syms' file for future
7281 gdb -batch -nx -mapped -readnow programname
7283 The `.syms' file is specific to the host machine on which GDB is run.
7284 It holds an exact image of GDB's internal symbol table. It cannot be
7285 shared across multiple host platforms.
7287 * longjmp() handling
7289 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7290 siglongjmp() without losing control. This feature has not yet been ported to
7291 all systems. It currently works on many 386 platforms, all MIPS-based
7292 platforms (SGI, DECstation, etc), and Sun3/4.
7296 Preliminary work has been put in to support the new Solaris OS from Sun. At
7297 this time, it can control and debug processes, but it is not capable of
7302 As always, many many bug fixes. The major areas were with g++, and mipsread.
7303 People using the MIPS-based platforms should experience fewer mysterious
7304 crashes and trashed symbol tables.
7306 *** Changes in GDB-4.4:
7308 * New machines supported (host and target)
7310 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7312 BSD Reno on Vax vax-dec-bsd
7313 Ultrix on Vax vax-dec-ultrix
7315 * New machines supported (target)
7317 AMD 29000 embedded, using EBMON a29k-none-none
7321 GDB continues to improve its handling of C++. `References' work better.
7322 The demangler has also been improved, and now deals with symbols mangled as
7323 per the Annotated C++ Reference Guide.
7325 GDB also now handles `stabs' symbol information embedded in MIPS
7326 `ecoff' symbol tables. Since the ecoff format was not easily
7327 extensible to handle new languages such as C++, this appeared to be a
7328 good way to put C++ debugging info into MIPS binaries. This option
7329 will be supported in the GNU C compiler, version 2, when it is
7332 * New features for SVR4
7334 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7335 shared libraries. Debugging dynamically linked programs should present
7336 only minor differences from debugging statically linked programs.
7338 The `info proc' command will print out information about any process
7339 on an SVR4 system (including the one you are debugging). At the moment,
7340 it prints the address mappings of the process.
7342 If you bring up GDB on another SVR4 system, please send mail to
7343 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7345 * Better dynamic linking support in SunOS
7347 Reading symbols from shared libraries which contain debugging symbols
7348 now works properly. However, there remain issues such as automatic
7349 skipping of `transfer vector' code during function calls, which
7350 make it harder to debug code in a shared library, than to debug the
7351 same code linked statically.
7355 GDB is now using the latest `getopt' routines from the FSF. This
7356 version accepts the -- prefix for options with long names. GDB will
7357 continue to accept the old forms (-option and +option) as well.
7358 Various single letter abbreviations for options have been explicity
7359 added to the option table so that they won't get overshadowed in the
7360 future by other options that begin with the same letter.
7364 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7365 Many assorted bugs have been handled. Many more remain to be handled.
7366 See the various ChangeLog files (primarily in gdb and bfd) for details.
7369 *** Changes in GDB-4.3:
7371 * New machines supported (host and target)
7373 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7374 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7375 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7377 * Almost SCO Unix support
7379 We had hoped to support:
7380 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7381 (except for core file support), but we discovered very late in the release
7382 that it has problems with process groups that render gdb unusable. Sorry
7383 about that. I encourage people to fix it and post the fixes.
7385 * Preliminary ELF and DWARF support
7387 GDB can read ELF object files on System V Release 4, and can handle
7388 debugging records for C, in DWARF format, in ELF files. This support
7389 is preliminary. If you bring up GDB on another SVR4 system, please
7390 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7395 GDB now uses the latest `readline' library. One user-visible change
7396 is that two tabs will list possible command completions, which previously
7397 required typing M-? (meta-question mark, or ESC ?).
7401 The `stepi' bug that many of you noticed has been squashed.
7402 Many bugs in C++ have been handled. Many more remain to be handled.
7403 See the various ChangeLog files (primarily in gdb and bfd) for details.
7405 * State of the MIPS world (in case you wondered):
7407 GDB can understand the symbol tables emitted by the compilers
7408 supplied by most vendors of MIPS-based machines, including DEC. These
7409 symbol tables are in a format that essentially nobody else uses.
7411 Some versions of gcc come with an assembler post-processor called
7412 mips-tfile. This program is required if you want to do source-level
7413 debugging of gcc-compiled programs. I believe FSF does not ship
7414 mips-tfile with gcc version 1, but it will eventually come with gcc
7417 Debugging of g++ output remains a problem. g++ version 1.xx does not
7418 really support it at all. (If you're lucky, you should be able to get
7419 line numbers and stack traces to work, but no parameters or local
7420 variables.) With some work it should be possible to improve the
7423 When gcc version 2 is released, you will have somewhat better luck.
7424 However, even then you will get confusing results for inheritance and
7427 We will eventually provide full debugging of g++ output on
7428 DECstations. This will probably involve some kind of stabs-in-ecoff
7429 encapulation, but the details have not been worked out yet.
7432 *** Changes in GDB-4.2:
7434 * Improved configuration
7436 Only one copy of `configure' exists now, and it is not self-modifying.
7437 Porting BFD is simpler.
7441 The `step' and `next' commands now only stop at the first instruction
7442 of a source line. This prevents the multiple stops that used to occur
7443 in switch statements, for-loops, etc. `Step' continues to stop if a
7444 function that has debugging information is called within the line.
7448 Lots of small bugs fixed. More remain.
7450 * New host supported (not target)
7452 Intel 386 PC clone running Mach i386-none-mach
7455 *** Changes in GDB-4.1:
7457 * Multiple source language support
7459 GDB now has internal scaffolding to handle several source languages.
7460 It determines the type of each source file from its filename extension,
7461 and will switch expression parsing and number formatting to match the
7462 language of the function in the currently selected stack frame.
7463 You can also specifically set the language to be used, with
7464 `set language c' or `set language modula-2'.
7468 GDB now has preliminary support for the GNU Modula-2 compiler,
7469 currently under development at the State University of New York at
7470 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7471 continue through the fall of 1991 and into 1992.
7473 Other Modula-2 compilers are currently not supported, and attempting to
7474 debug programs compiled with them will likely result in an error as the
7475 symbol table is read. Feel free to work on it, though!
7477 There are hooks in GDB for strict type checking and range checking,
7478 in the `Modula-2 philosophy', but they do not currently work.
7482 GDB can now write to executable and core files (e.g. patch
7483 a variable's value). You must turn this switch on, specify
7484 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7485 by assigning a new value to a variable. Modifications take
7488 * Automatic SunOS shared library reading
7490 When you run your program, GDB automatically determines where its
7491 shared libraries (if any) have been loaded, and reads their symbols.
7492 The `share' command is no longer needed. This also works when
7493 examining core files.
7497 You can specify the number of lines that the `list' command shows.
7500 * New machines supported (host and target)
7502 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7503 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7504 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7506 * New hosts supported (not targets)
7508 IBM RT/PC: romp-ibm-aix or rtpc
7510 * New targets supported (not hosts)
7512 AMD 29000 embedded with COFF a29k-none-coff
7513 AMD 29000 embedded with a.out a29k-none-aout
7514 Ultracomputer remote kernel debug a29k-nyu-kern
7516 * New remote interfaces
7522 *** Changes in GDB-4.0:
7526 Wide output is wrapped at good places to make the output more readable.
7528 Gdb now supports cross-debugging from a host machine of one type to a
7529 target machine of another type. Communication with the target system
7530 is over serial lines. The ``target'' command handles connecting to the
7531 remote system; the ``load'' command will download a program into the
7532 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7533 also supports debugging of realtime processes running under VxWorks,
7534 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7535 stub on the target system.
7537 New CPUs supported include the AMD 29000 and Intel 960.
7539 GDB now reads object files and symbol tables via a ``binary file''
7540 library, which allows a single copy of GDB to debug programs of multiple
7541 object file types such as a.out and coff.
7543 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7544 refcard.dvi and refcard.ps are available to format it).
7547 * Control-Variable user interface simplified
7549 All variables that control the operation of the debugger can be set
7550 by the ``set'' command, and displayed by the ``show'' command.
7552 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7553 ``Show prompt'' produces the response:
7554 Gdb's prompt is new-gdb=>.
7556 What follows are the NEW set commands. The command ``help set'' will
7557 print a complete list of old and new set commands. ``help set FOO''
7558 will give a longer description of the variable FOO. ``show'' will show
7559 all of the variable descriptions and their current settings.
7561 confirm on/off: Enables warning questions for operations that are
7562 hard to recover from, e.g. rerunning the program while
7563 it is already running. Default is ON.
7565 editing on/off: Enables EMACS style command line editing
7566 of input. Previous lines can be recalled with
7567 control-P, the current line can be edited with control-B,
7568 you can search for commands with control-R, etc.
7571 history filename NAME: NAME is where the gdb command history
7572 will be stored. The default is .gdb_history,
7573 or the value of the environment variable
7576 history size N: The size, in commands, of the command history. The
7577 default is 256, or the value of the environment variable
7580 history save on/off: If this value is set to ON, the history file will
7581 be saved after exiting gdb. If set to OFF, the
7582 file will not be saved. The default is OFF.
7584 history expansion on/off: If this value is set to ON, then csh-like
7585 history expansion will be performed on
7586 command line input. The default is OFF.
7588 radix N: Sets the default radix for input and output. It can be set
7589 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7590 in the current radix, so "set radix 10" is always a no-op.
7592 height N: This integer value is the number of lines on a page. Default
7593 is 24, the current `stty rows'' setting, or the ``li#''
7594 setting from the termcap entry matching the environment
7597 width N: This integer value is the number of characters on a line.
7598 Default is 80, the current `stty cols'' setting, or the ``co#''
7599 setting from the termcap entry matching the environment
7602 Note: ``set screensize'' is obsolete. Use ``set height'' and
7603 ``set width'' instead.
7605 print address on/off: Print memory addresses in various command displays,
7606 such as stack traces and structure values. Gdb looks
7607 more ``symbolic'' if you turn this off; it looks more
7608 ``machine level'' with it on. Default is ON.
7610 print array on/off: Prettyprint arrays. New convenient format! Default
7613 print demangle on/off: Print C++ symbols in "source" form if on,
7616 print asm-demangle on/off: Same, for assembler level printouts
7619 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7622 * Support for Epoch Environment.
7624 The epoch environment is a version of Emacs v18 with windowing. One
7625 new command, ``inspect'', is identical to ``print'', except that if you
7626 are running in the epoch environment, the value is printed in its own
7630 * Support for Shared Libraries
7632 GDB can now debug programs and core files that use SunOS shared libraries.
7633 Symbols from a shared library cannot be referenced
7634 before the shared library has been linked with the program (this
7635 happens after you type ``run'' and before the function main() is entered).
7636 At any time after this linking (including when examining core files
7637 from dynamically linked programs), gdb reads the symbols from each
7638 shared library when you type the ``sharedlibrary'' command.
7639 It can be abbreviated ``share''.
7641 sharedlibrary REGEXP: Load shared object library symbols for files
7642 matching a unix regular expression. No argument
7643 indicates to load symbols for all shared libraries.
7645 info sharedlibrary: Status of loaded shared libraries.
7650 A watchpoint stops execution of a program whenever the value of an
7651 expression changes. Checking for this slows down execution
7652 tremendously whenever you are in the scope of the expression, but is
7653 quite useful for catching tough ``bit-spreader'' or pointer misuse
7654 problems. Some machines such as the 386 have hardware for doing this
7655 more quickly, and future versions of gdb will use this hardware.
7657 watch EXP: Set a watchpoint (breakpoint) for an expression.
7659 info watchpoints: Information about your watchpoints.
7661 delete N: Deletes watchpoint number N (same as breakpoints).
7662 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7663 enable N: Re-enables watchpoint number N (same as breakpoints).
7666 * C++ multiple inheritance
7668 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7671 * C++ exception handling
7673 Gdb now supports limited C++ exception handling. Besides the existing
7674 ability to breakpoint on an exception handler, gdb can breakpoint on
7675 the raising of an exception (before the stack is peeled back to the
7678 catch FOO: If there is a FOO exception handler in the dynamic scope,
7679 set a breakpoint to catch exceptions which may be raised there.
7680 Multiple exceptions (``catch foo bar baz'') may be caught.
7682 info catch: Lists all exceptions which may be caught in the
7683 current stack frame.
7686 * Minor command changes
7688 The command ``call func (arg, arg, ...)'' now acts like the print
7689 command, except it does not print or save a value if the function's result
7690 is void. This is similar to dbx usage.
7692 The ``up'' and ``down'' commands now always print the frame they end up
7693 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7694 frames without printing.
7696 * New directory command
7698 'dir' now adds directories to the FRONT of the source search path.
7699 The path starts off empty. Source files that contain debug information
7700 about the directory in which they were compiled can be found even
7701 with an empty path; Sun CC and GCC include this information. If GDB can't
7702 find your source file in the current directory, type "dir .".
7704 * Configuring GDB for compilation
7706 For normal use, type ``./configure host''. See README or gdb.texinfo
7709 GDB now handles cross debugging. If you are remotely debugging between
7710 two different machines, type ``./configure host -target=targ''.
7711 Host is the machine where GDB will run; targ is the machine
7712 where the program that you are debugging will run.