1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 9
6 * Debugging MS-Windows processes now sets $_exitsignal when the
7 inferior is terminated by a signal, instead of setting $_exitcode.
9 * Multithreaded symbol loading has now been enabled by default on systems
10 that support it (see entry for GDB 9, below), providing faster
11 performance for programs with many symbols.
13 * The $_siginfo convenience variable now also works on Windows targets,
14 and will display the EXCEPTION_RECORD of the last handled exception.
18 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
19 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
20 Set or show the option 'exec-file-mismatch'. When GDB attaches to
21 a running process and can determine the name of the executable file
22 the process runs, this new option indicates whether to detect mismatch
23 between the name of the current executable file loaded by GDB
24 and the name of the executable file used to start the process.
25 If 'ask', the default, display a warning and ask the user
26 whether to load the process executable file; if 'warn', just display
27 a warning; if 'off', don't attempt to detect a mismatch.
31 * 'thread-exited' event is now available in the annotations interface.
33 * New built-in convenience variables $_gdb_major and $_gdb_minor
34 provide the GDB version. They are handy for conditionally using
35 features available only in or since specific GDB versions, in
36 scripts that should work error-free with many different versions,
37 such as in system-wide init files.
39 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
40 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
41 of the GDB settings and the GDB maintenance settings. They are handy
42 for changing the logic of user defined commands depending on the
45 * GDB now supports Thread Local Storage (TLS) variables on several
46 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
47 architectures require kernel changes. TLS is not yet supported for
48 amd64 and i386 process core dumps.
50 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
51 addresses that required unmasking are shown in the backtrace with the
54 * Two new convenience functions $_cimag and $_creal that extract the
55 imaginary and real parts respectively from complex numbers.
57 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
58 provide the exitcode or exit status of the shell commands launched by
59 GDB commands such as "shell", "pipe" and "make".
61 * The command define-prefix can now define user defined prefix commands.
62 User defined commands can now be defined using these user defined prefix
65 * Command names can now use the . character.
67 * The RX port now supports XML target descriptions.
69 * GDB now shows the Ada task names at more places, e.g. in task switching
72 * GDB can now be compiled with Python 3 on Windows.
74 * New convenience variable $_ada_exception holds the address of the
75 Ada exception being thrown. This is set by Ada-related catchpoints.
77 * GDB can now place breakpoints on nested functions and subroutines in
78 Fortran code. The '::' operator can be used between parent and
79 child scopes when placing breakpoints, for example:
81 (gdb) break outer_function::inner_function
83 The 'outer_function::' prefix is only needed if 'inner_function' is
84 not visible in the current scope.
86 * In addition to the system-wide gdbinit file, if configured with
87 --with-system-gdbinit-dir, GDB will now also load files in that directory
88 as system gdbinit files, unless the -nx or -n flag is provided. Files
89 with extensions .gdb, .py and .scm are supported as long as GDB was
90 compiled with support for that language.
92 * GDB now supports multithreaded symbol loading for higher performance.
93 This feature is still in testing, so it is disabled by default. You
94 can turn it on using 'maint set worker-threads unlimited'.
96 * Multi-target debugging support
98 GDB now supports debugging multiple target connections
99 simultaneously. For example, you can now have each inferior
100 connected to different remote servers running in different machines,
101 or have one inferior debugging a local native process, an inferior
102 debugging a core dump, etc.
104 This support is experimental and comes with some limitations -- you
105 can only resume multiple targets simultaneously if all targets
106 support non-stop mode, and all remote stubs or servers must support
107 the same set of remote protocol features exactly. See also "info
108 connections" and "add-inferior -no-connection" below, and "maint set
109 target-non-stop" in the user manual.
113 ** The gdb.Value type has a new method 'format_string' which returns a
114 string representing the value. The formatting is controlled by the
115 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
116 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
117 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
119 ** gdb.Type has a new property 'objfile' which returns the objfile the
122 ** The frame information printed by the python frame filtering code
123 is now consistent with what the 'backtrace' command prints when
124 there are no filters, or when the 'backtrace' '-no-filters' option
127 ** The new function gdb.lookup_static_symbol can be used to look up
128 symbols with static linkage.
130 ** The new function gdb.lookup_static_symbols can be used to look up
131 all static symbols with static linkage.
133 ** gdb.Objfile has new methods 'lookup_global_symbol' and
134 'lookup_static_symbol' to lookup a symbol from this objfile only.
136 ** gdb.Block now supports the dictionary syntax for accessing symbols in
137 this block (e.g. block['local_variable']).
141 | [COMMAND] | SHELL_COMMAND
142 | -d DELIM COMMAND DELIM SHELL_COMMAND
143 pipe [COMMAND] | SHELL_COMMAND
144 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
145 Executes COMMAND and sends its output to SHELL_COMMAND.
146 With no COMMAND, repeat the last executed command
147 and send its output to SHELL_COMMAND.
149 define-prefix COMMAND
150 Define or mark a command as a user-defined prefix command.
152 with SETTING [VALUE] [-- COMMAND]
153 w SETTING [VALUE] [-- COMMAND]
154 Temporarily set SETTING, run COMMAND, and restore SETTING.
155 Usage: with SETTING -- COMMAND
156 With no COMMAND, repeats the last executed command.
157 SETTING is any GDB setting you can change with the "set"
158 subcommands. For example, 'with language c -- print someobj'
159 temporarily switches to the C language in order to print someobj.
160 Settings can be combined: 'w lang c -- w print elements unlimited --
161 usercmd' switches to the C language and runs usercmd with no limit
162 of array elements to print.
164 maint with SETTING [VALUE] [-- COMMAND]
165 Like "with", but works with "maintenance set" settings.
167 set may-call-functions [on|off]
168 show may-call-functions
169 This controls whether GDB will attempt to call functions in
170 the program, such as with expressions in the print command. It
171 defaults to on. Calling functions in the program being debugged
172 can have undesired side effects. It is now possible to forbid
173 such function calls. If function calls are forbidden, GDB will throw
174 an error when a command (such as print expression) calls a function
177 set print finish [on|off]
179 This controls whether the `finish' command will display the value
180 that is returned by the current function. When `off', the value is
181 still entered into the value history, but it is not printed. The
186 Allows deeply nested structures to be simplified when printing by
187 replacing deeply nested parts (beyond the max-depth) with ellipses.
188 The default max-depth is 20, but this can be set to unlimited to get
189 the old behavior back.
191 set print raw-values [on|off]
192 show print raw-values
193 By default, GDB applies the enabled pretty printers when printing a
194 value. This allows to ignore the enabled pretty printers for a series
195 of commands. The default is 'off'.
197 set logging debugredirect [on|off]
198 By default, GDB debug output will go to both the terminal and the logfile.
199 Set if you want debug output to go only to the log file.
201 set style title foreground COLOR
202 set style title background COLOR
203 set style title intensity VALUE
204 Control the styling of titles.
206 set style highlight foreground COLOR
207 set style highlight background COLOR
208 set style highlight intensity VALUE
209 Control the styling of highlightings.
211 maint set worker-threads
212 maint show worker-threads
213 Control the number of worker threads that can be used by GDB. The
214 default is 0. "unlimited" lets GDB choose a number that is
215 reasonable. Currently worker threads are only used when demangling
216 the names of linker symbols.
218 set style tui-border foreground COLOR
219 set style tui-border background COLOR
220 Control the styling of TUI borders.
222 set style tui-active-border foreground COLOR
223 set style tui-active-border background COLOR
224 Control the styling of the active TUI border.
226 maint set test-settings KIND
227 maint show test-settings KIND
228 A set of commands used by the testsuite for exercising the settings
231 maint set tui-resize-message [on|off]
232 maint show tui-resize-message
233 Control whether GDB prints a message each time the terminal is
234 resized when in TUI mode. This is primarily useful for testing the
237 set print frame-info [short-location|location|location-and-address
238 |source-and-location|source-line|auto]
239 show print frame-info
240 This controls what frame information is printed by the commands printing
241 a frame. This setting will e.g. influence the behaviour of 'backtrace',
242 'frame', 'stepi'. The python frame filtering also respect this setting.
243 The 'backtrace' '-frame-info' option can override this global setting.
245 set tui compact-source
246 show tui compact-source
248 Enable the "compact" display mode for the TUI source window. The
249 compact display uses only as much space as is needed for the line
250 numbers in the current file, and only a single space to separate the
251 line numbers from the source.
253 info modules [-q] [REGEXP]
254 Return a list of Fortran modules matching REGEXP, or all modules if
257 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
258 Return a list of functions within all modules, grouped by module.
259 The list of functions can be restricted with the optional regular
260 expressions. MODULE_REGEXP matches against the module name,
261 TYPE_REGEXP matches against the function type signature, and REGEXP
262 matches against the function name.
264 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
265 Return a list of variables within all modules, grouped by module.
266 The list of variables can be restricted with the optional regular
267 expressions. MODULE_REGEXP matches against the module name,
268 TYPE_REGEXP matches against the variable type, and REGEXP matches
269 against the variable name.
271 set debug remote-packet-max-chars
272 show debug remote-packet-max-chars
273 Controls the number of characters to output in a remote packet when using
275 The default is 512 bytes.
278 Lists the target connections currently in use.
283 The "help" command uses the title style to enhance the
284 readibility of its output by styling the classes and
288 Similarly to "help", the "apropos" command also uses the
289 title style for the command names. "apropos" accepts now
290 a flag "-v" (verbose) to show the full documentation
291 of matching commands and to use the highlight style to mark
292 the documentation parts matching REGEXP.
296 The GDB printf and eval commands can now print C-style and Ada-style
297 string convenience variables without calling functions in the program.
298 This allows to do formatted printing of strings without having
299 a running inferior, or when debugging a core dump.
301 info sources [-dirname | -basename] [--] [REGEXP]
302 This command has now optional arguments to only print the files
303 whose names match REGEXP. The arguments -dirname and -basename
304 allow to restrict matching respectively to the dirname and basename
308 The "show style" and its subcommands are now styling
309 a style name in their output using its own style, to help
310 the user visualize the different styles.
312 set print frame-arguments
313 The new value 'presence' indicates to only indicate the presence of
314 arguments using ..., instead of printing argument names and values.
316 set print raw-frame-arguments
317 show print raw-frame-arguments
319 These commands replace the similarly-named "set/show print raw
320 frame-arguments" commands (now with a dash instead of a space). The
321 old commands are now deprecated and may be removed in a future
324 add-inferior [-no-connection]
325 The add-inferior command now supports a "-no-connection" flag that
326 makes the new inferior start with no target connection associated.
327 By default, the new inferior inherits the target connection of the
328 current inferior. See also "info connections".
331 This command's output now includes a new "Connection" column
332 indicating which target connection an inferior is bound to. See
333 "info connections" above.
335 maint test-options require-delimiter
336 maint test-options unknown-is-error
337 maint test-options unknown-is-operand
338 maint show test-options-completion-result
339 Commands used by the testsuite to validate the command options
342 focus, winheight, +, -, >, <
343 These commands are now case-sensitive.
345 * New command options, command completion
347 GDB now has a standard infrastructure to support dash-style command
348 options ('-OPT'). One benefit is that commands that use it can
349 easily support completion of command line arguments. Try "CMD
350 -[TAB]" or "help CMD" to find options supported by a command. Over
351 time, we intend to migrate most commands to this infrastructure. A
352 number of commands got support for new command options in this
355 ** The "print" and "compile print" commands now support a number of
356 options that allow overriding relevant global print settings as
357 set by "set print" subcommands:
361 -array-indexes [on|off]
362 -elements NUMBER|unlimited
367 -repeats NUMBER|unlimited
368 -static-members [on|off]
373 Note that because the "print"/"compile print" commands accept
374 arbitrary expressions which may look like options (including
375 abbreviations), if you specify any command option, then you must
376 use a double dash ("--") to mark the end of argument processing.
378 ** The "backtrace" command now supports a number of options that
379 allow overriding relevant global print settings as set by "set
380 backtrace" and "set print" subcommands:
382 -entry-values no|only|preferred|if-needed|both|compact|default
383 -frame-arguments all|scalars|none
384 -raw-frame-arguments [on|off]
385 -frame-info auto|source-line|location|source-and-location
386 |location-and-address|short-location
390 In addition, the full/no-filters/hide qualifiers are now also
391 exposed as command options too:
397 ** The "frame apply", "tfaas" and "faas" commands similarly now
398 support the following options:
403 ** The new "info sources" options -dirname and -basename options
404 are using the standard '-OPT' infrastructure.
406 All options above can also be abbreviated. The argument of boolean
407 (on/off) options can be 0/1 too, and also the argument is assumed
408 "on" if omitted. This allows writing compact command invocations,
411 (gdb) p -ra -p -o 0 -- *myptr
413 The above is equivalent to:
415 (gdb) print -raw-values -pretty -object off -- *myptr
417 ** The "info types" command now supports the '-q' flag to disable
418 printing of some header information in a similar fashion to "info
419 variables" and "info functions".
421 ** The "info variables", "info functions", and "whereis" commands
422 now take a '-n' flag that excludes non-debug symbols (symbols
423 from the symbol table, not from the debug info such as DWARF)
426 * Completion improvements
428 ** GDB can now complete the options of the "thread apply all" and
429 "taas" commands, and their "-ascending" option can now be
432 ** GDB can now complete the options of the "info threads", "info
433 functions", "info variables", "info locals", and "info args"
436 ** GDB can now complete the options of the "compile file" and
437 "compile code" commands. The "compile file" command now
438 completes on filenames.
440 ** GDB can now complete the backtrace command's
441 "full/no-filters/hide" qualifiers.
443 * In settings, you can now abbreviate "unlimited".
445 E.g., "set print elements u" is now equivalent to "set print
451 This lists all the possible completions for the rest of the line, if it
452 were to be given as a command itself. This is intended for use by MI
453 frontends in cases when separate CLI and MI channels cannot be used.
455 -catch-throw, -catch-rethrow, and -catch-catch
456 These can be used to catch C++ exceptions in a similar fashion to
457 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
459 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
460 These commands are the MI equivalent of the CLI commands 'info
461 functions', 'info types', and 'info variables' respectively.
463 -symbol-info-modules, this is the MI equivalent of the CLI 'info
466 -symbol-info-module-functions and -symbol-info-module-variables.
467 These commands are the MI equivalent of the CLI commands 'info
468 module functions' and 'info module variables'.
472 ** The default version of the MI interpreter is now 3 (-i=mi3).
474 ** The output of information about multi-location breakpoints (which is
475 syntactically incorrect in MI 2) has changed in MI 3. This affects
476 the following commands and events:
480 - =breakpoint-created
481 - =breakpoint-modified
483 The -fix-multi-location-breakpoint-output command can be used to enable
484 this behavior with previous MI versions.
486 ** Backtraces and frames include a new optional field addr_flags which is
487 given after the addr field. On AArch64 this contains PAC if the address
488 has been masked in the frame. On all other targets the field is not
493 The testsuite now creates the files gdb.cmd (containing the arguments
494 used to launch GDB) and gdb.in (containing all the commands sent to
495 GDB) in the output directory for each test script. Multiple invocations
496 are appended with .1, .2, .3 etc.
498 * Building GDB and GDBserver now requires GNU make >= 3.82.
500 Using another implementation of the make program or an earlier version of
501 GNU make to build GDB or GDBserver is not supported.
503 * Building GDB now requires GNU readline >= 7.0.
505 GDB now bundles GNU readline 8.0, but if you choose to use
506 --with-system-readline, only readline >= 7.0 can be used.
508 * The TUI SingleKey keymap is now named "SingleKey". This can be used
509 from .inputrc to bind keys in this keymap. This feature is only
510 available when gdb is built against GNU readline 8.0 or later.
512 * Removed targets and native configurations
514 GDB no longer supports debugging the Cell Broadband Engine. This includes
515 both debugging standalone Cell/B.E. SPU applications and integrated debugging
516 of Cell/B.E. applications that use both the PPU and SPU architectures.
522 * Removed targets and native configurations
524 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
527 *** Changes in GDB 8.3
529 * GDB and GDBserver now support access to additional registers on
530 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
533 * GDB now has experimental support for the compilation and injection of
534 C++ source code into the inferior. This beta release does not include
535 support for several language features, such as templates, constructors,
538 This feature requires GCC 7.1 or higher built with libcp1.so
541 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
542 can be passed using the '[ADDRESS]:PORT' notation, or the regular
543 'ADDRESS:PORT' method.
545 * DWARF index cache: GDB can now automatically save indices of DWARF
546 symbols on disk to speed up further loading of the same binaries.
548 * Ada task switching is now supported on aarch64-elf targets when
549 debugging a program using the Ravenscar Profile. For more information,
550 see the "Tasking Support when using the Ravenscar Profile" section
551 in the GDB user manual.
553 * GDB in batch mode now exits with status 1 if the last command to be
556 * The RISC-V target now supports target descriptions.
558 * System call catchpoints now support system call aliases on FreeBSD.
559 When the ABI of a system call changes in FreeBSD, this is
560 implemented by leaving a compatibility system call using the old ABI
561 at the existing number and allocating a new system call number for
562 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
563 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
564 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
565 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
566 so that a system call catchpoint for the 'kevent' system call will
567 catch invocations of both the 'kevent' and 'freebsd11_kevent'
568 binaries. This ensures that 'kevent' system calls are caught for
569 binaries using either the old or new ABIs.
571 * Terminal styling is now available for the CLI and the TUI. GNU
572 Source Highlight can additionally be used to provide styling of
573 source code snippets. See the "set style" commands, below, for more
576 * Removed support for old demangling styles arm, edg, gnu, hp and
581 set debug compile-cplus-types
582 show debug compile-cplus-types
583 Control the display of debug output about type conversion in the
584 C++ compile feature. Commands have no effect while compiliong
589 Control whether debug output about files/functions skipping is
592 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
593 Apply a command to some frames.
594 FLAG arguments allow to control what output to produce and how to handle
595 errors raised when applying COMMAND to a frame.
598 Apply a command to all threads (ignoring errors and empty output).
599 Shortcut for 'thread apply all -s COMMAND'.
602 Apply a command to all frames (ignoring errors and empty output).
603 Shortcut for 'frame apply all -s COMMAND'.
606 Apply a command to all frames of all threads (ignoring errors and empty
608 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
610 maint set dwarf unwinders (on|off)
611 maint show dwarf unwinders
612 Control whether DWARF unwinders can be used.
615 Display a list of open files for a process.
619 Changes to the "frame", "select-frame", and "info frame" CLI commands.
620 These commands all now take a frame specification which
621 is either a frame level, or one of the keywords 'level', 'address',
622 'function', or 'view' followed by a parameter. Selecting a frame by
623 address, or viewing a frame outside the current backtrace now
624 requires the use of a keyword. Selecting a frame by level is
625 unchanged. The MI comment "-stack-select-frame" is unchanged.
627 target remote FILENAME
628 target extended-remote FILENAME
629 If FILENAME is a Unix domain socket, GDB will attempt to connect
630 to this socket instead of opening FILENAME as a character device.
632 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
633 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
634 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
635 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
636 These commands can now print only the searched entities
637 matching the provided regexp(s), giving a condition
638 on the entity names or entity types. The flag -q disables
639 printing headers or informations messages.
645 These commands now determine the syntax for the shown entities
646 according to the language chosen by `set language'. In particular,
647 `set language auto' means to automatically choose the language of
650 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
651 The 'thread apply' command accepts new FLAG arguments.
652 FLAG arguments allow to control what output to produce and how to handle
653 errors raised when applying COMMAND to a thread.
655 set tui tab-width NCHARS
656 show tui tab-width NCHARS
657 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
659 set style enabled [on|off]
661 Enable or disable terminal styling. Styling is enabled by default
662 on most hosts, but disabled by default when in batch mode.
664 set style sources [on|off]
666 Enable or disable source code styling. Source code styling is
667 enabled by default, but only takes effect if styling in general is
668 enabled, and if GDB was linked with GNU Source Highlight.
670 set style filename foreground COLOR
671 set style filename background COLOR
672 set style filename intensity VALUE
673 Control the styling of file names.
675 set style function foreground COLOR
676 set style function background COLOR
677 set style function intensity VALUE
678 Control the styling of function names.
680 set style variable foreground COLOR
681 set style variable background COLOR
682 set style variable intensity VALUE
683 Control the styling of variable names.
685 set style address foreground COLOR
686 set style address background COLOR
687 set style address intensity VALUE
688 Control the styling of addresses.
692 ** The '-data-disassemble' MI command now accepts an '-a' option to
693 disassemble the whole function surrounding the given program
694 counter value or function name. Support for this feature can be
695 verified by using the "-list-features" command, which should
696 contain "data-disassemble-a-option".
698 ** Command responses and notifications that include a frame now include
699 the frame's architecture in a new "arch" attribute.
701 * New native configurations
703 GNU/Linux/RISC-V riscv*-*-linux*
704 FreeBSD/riscv riscv*-*-freebsd*
708 GNU/Linux/RISC-V riscv*-*-linux*
710 CSKY GNU/LINUX csky*-*-linux
711 FreeBSD/riscv riscv*-*-freebsd*
713 GNU/Linux/OpenRISC or1k*-*-linux*
717 GDB no longer supports native debugging on versions of MS-Windows
722 ** GDB no longer supports Python versions less than 2.6.
724 ** The gdb.Inferior type has a new 'progspace' property, which is the program
725 space associated to that inferior.
727 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
728 of objfiles associated to that program space.
730 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
731 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
734 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
735 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
736 correct and did not work properly.
738 ** The gdb.Value type has a new constructor, which is used to construct a
739 gdb.Value from a Python buffer object and a gdb.Type.
745 Enable or disable the undefined behavior sanitizer. This is
746 disabled by default, but passing --enable-ubsan=yes or
747 --enable-ubsan=auto to configure will enable it. Enabling this can
748 cause a performance penalty. The undefined behavior sanitizer was
749 first introduced in GCC 4.9.
751 *** Changes in GDB 8.2
753 * The 'set disassembler-options' command now supports specifying options
756 * The 'symbol-file' command now accepts an '-o' option to add a relative
757 offset to all sections.
759 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
760 a relative offset to all sections, but it allows to override the load
761 address of individual sections using '-s'.
763 * The 'add-symbol-file' command no longer requires the second argument
764 (address of the text section).
766 * The endianness used with the 'set endian auto' mode in the absence of
767 an executable selected for debugging is now the last endianness chosen
768 either by one of the 'set endian big' and 'set endian little' commands
769 or by inferring from the last executable used, rather than the startup
772 * The pager now allows a "c" response, meaning to disable the pager
773 for the rest of the current command.
775 * The commands 'info variables/functions/types' now show the source line
776 numbers of symbol definitions when available.
778 * 'info proc' now works on running processes on FreeBSD systems and core
779 files created on FreeBSD systems.
781 * C expressions can now use _Alignof, and C++ expressions can now use
784 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
785 the vector length while the process is running.
791 Control display of debugging info regarding the FreeBSD native target.
793 set|show varsize-limit
794 This new setting allows the user to control the maximum size of Ada
795 objects being printed when those objects have a variable type,
796 instead of that maximum size being hardcoded to 65536 bytes.
798 set|show record btrace cpu
799 Controls the processor to be used for enabling errata workarounds for
802 maint check libthread-db
803 Run integrity checks on the current inferior's thread debugging
806 maint set check-libthread-db (on|off)
807 maint show check-libthread-db
808 Control whether to run integrity checks on inferior specific thread
809 debugging libraries as they are loaded. The default is not to
814 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
816 ** The commands attached to a breakpoint can be set by assigning to
817 the breakpoint's "commands" field.
819 ** gdb.execute can now execute multi-line gdb commands.
821 ** The new functions gdb.convenience_variable and
822 gdb.set_convenience_variable can be used to get and set the value
823 of convenience variables.
825 ** A gdb.Parameter will no longer print the "set" help text on an
826 ordinary "set"; instead by default a "set" will be silent unless
827 the get_set_string method returns a non-empty string.
831 RiscV ELF riscv*-*-elf
833 * Removed targets and native configurations
835 m88k running OpenBSD m88*-*-openbsd*
836 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
837 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
838 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
840 * Aarch64/Linux hardware watchpoints improvements
842 Hardware watchpoints on unaligned addresses are now properly
843 supported when running Linux kernel 4.10 or higher: read and access
844 watchpoints are no longer spuriously missed, and all watchpoints
845 lengths between 1 and 8 bytes are supported. On older kernels,
846 watchpoints set on unaligned addresses are no longer missed, with
847 the tradeoff that there is a possibility of false hits being
852 --enable-codesign=CERT
853 This can be used to invoke "codesign -s CERT" after building gdb.
854 This option is useful on macOS, where code signing is required for
855 gdb to work properly.
857 --disable-gdbcli has been removed
858 This is now silently accepted, but does nothing.
860 *** Changes in GDB 8.1
862 * GDB now supports dynamically creating arbitrary register groups specified
863 in XML target descriptions. This allows for finer grain grouping of
864 registers on systems with a large amount of registers.
866 * The 'ptype' command now accepts a '/o' flag, which prints the
867 offsets and sizes of fields in a struct, like the pahole(1) tool.
869 * New "--readnever" command line option instructs GDB to not read each
870 symbol file's symbolic debug information. This makes startup faster
871 but at the expense of not being able to perform symbolic debugging.
872 This option is intended for use cases where symbolic debugging will
873 not be used, e.g., when you only need to dump the debuggee's core.
875 * GDB now uses the GNU MPFR library, if available, to emulate target
876 floating-point arithmetic during expression evaluation when the target
877 uses different floating-point formats than the host. At least version
878 3.1 of GNU MPFR is required.
880 * GDB now supports access to the guarded-storage-control registers and the
881 software-based guarded-storage broadcast control registers on IBM z14.
883 * On Unix systems, GDB now supports transmitting environment variables
884 that are to be set or unset to GDBserver. These variables will
885 affect the environment to be passed to the remote inferior.
887 To inform GDB of environment variables that are to be transmitted to
888 GDBserver, use the "set environment" command. Only user set
889 environment variables are sent to GDBserver.
891 To inform GDB of environment variables that are to be unset before
892 the remote inferior is started by the GDBserver, use the "unset
893 environment" command.
895 * Completion improvements
897 ** GDB can now complete function parameters in linespecs and
898 explicit locations without quoting. When setting breakpoints,
899 quoting around functions names to help with TAB-completion is
900 generally no longer necessary. For example, this now completes
903 (gdb) b function(in[TAB]
904 (gdb) b function(int)
906 Related, GDB is no longer confused with completing functions in
907 C++ anonymous namespaces:
910 (gdb) b (anonymous namespace)::[TAB][TAB]
911 (anonymous namespace)::a_function()
912 (anonymous namespace)::b_function()
914 ** GDB now has much improved linespec and explicit locations TAB
915 completion support, that better understands what you're
916 completing and offers better suggestions. For example, GDB no
917 longer offers data symbols as possible completions when you're
918 setting a breakpoint.
920 ** GDB now TAB-completes label symbol names.
922 ** The "complete" command now mimics TAB completion accurately.
924 * New command line options (gcore)
927 Dump all memory mappings.
929 * Breakpoints on C++ functions are now set on all scopes by default
931 By default, breakpoints on functions/methods are now interpreted as
932 specifying all functions with the given name ignoring missing
933 leading scopes (namespaces and classes).
935 For example, assuming a C++ program with symbols named:
940 both commands "break func()" and "break B::func()" set a breakpoint
943 You can use the new flag "-qualified" to override this. This makes
944 GDB interpret the specified function name as a complete
945 fully-qualified name instead. For example, using the same C++
946 program, the "break -q B::func" command sets a breakpoint on
947 "B::func", only. A parameter has been added to the Python
948 gdb.Breakpoint constructor to achieve the same result when creating
949 a breakpoint from Python.
951 * Breakpoints on functions marked with C++ ABI tags
953 GDB can now set breakpoints on functions marked with C++ ABI tags
954 (e.g., [abi:cxx11]). See here for a description of ABI tags:
955 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
957 Functions with a C++11 abi tag are demangled/displayed like this:
959 function[abi:cxx11](int)
962 You can now set a breakpoint on such functions simply as if they had
965 (gdb) b function(int)
967 Or if you need to disambiguate between tags, like:
969 (gdb) b function[abi:other_tag](int)
971 Tab completion was adjusted accordingly as well.
975 ** New events gdb.new_inferior, gdb.inferior_deleted, and
976 gdb.new_thread are emitted. See the manual for further
977 description of these.
979 ** A new function, "gdb.rbreak" has been added to the Python API.
980 This function allows the setting of a large number of breakpoints
981 via a regex pattern in Python. See the manual for further details.
983 ** Python breakpoints can now accept explicit locations. See the
984 manual for a further description of this feature.
987 * New features in the GDB remote stub, GDBserver
989 ** GDBserver is now able to start inferior processes with a
990 specified initial working directory.
992 The user can set the desired working directory to be used from
993 GDB using the new "set cwd" command.
995 ** New "--selftest" command line option runs some GDBserver self
996 tests. These self tests are disabled in releases.
998 ** On Unix systems, GDBserver now does globbing expansion and variable
999 substitution in inferior command line arguments.
1001 This is done by starting inferiors using a shell, like GDB does.
1002 See "set startup-with-shell" in the user manual for how to disable
1003 this from GDB when using "target extended-remote". When using
1004 "target remote", you can disable the startup with shell by using the
1005 new "--no-startup-with-shell" GDBserver command line option.
1007 ** On Unix systems, GDBserver now supports receiving environment
1008 variables that are to be set or unset from GDB. These variables
1009 will affect the environment to be passed to the inferior.
1011 * When catching an Ada exception raised with a message, GDB now prints
1012 the message in the catchpoint hit notification. In GDB/MI mode, that
1013 information is provided as an extra field named "exception-message"
1014 in the *stopped notification.
1016 * Trait objects can now be inspected When debugging Rust code. This
1017 requires compiler support which will appear in Rust 1.24.
1019 * New remote packets
1021 QEnvironmentHexEncoded
1022 Inform GDBserver of an environment variable that is to be passed to
1023 the inferior when starting it.
1026 Inform GDBserver of an environment variable that is to be unset
1027 before starting the remote inferior.
1030 Inform GDBserver that the environment should be reset (i.e.,
1031 user-set environment variables should be unset).
1034 Indicates whether the inferior must be started with a shell or not.
1037 Tell GDBserver that the inferior to be started should use a specific
1040 * The "maintenance print c-tdesc" command now takes an optional
1041 argument which is the file name of XML target description.
1043 * The "maintenance selftest" command now takes an optional argument to
1044 filter the tests to be run.
1046 * The "enable", and "disable" commands now accept a range of
1047 breakpoint locations, e.g. "enable 1.3-5".
1052 Set and show the current working directory for the inferior.
1054 set|show compile-gcc
1055 Set and show compilation command used for compiling and injecting code
1056 with the 'compile' commands.
1058 set debug separate-debug-file
1059 show debug separate-debug-file
1060 Control the display of debug output about separate debug file search.
1062 set dump-excluded-mappings
1063 show dump-excluded-mappings
1064 Control whether mappings marked with the VM_DONTDUMP flag should be
1065 dumped when generating a core file.
1067 maint info selftests
1068 List the registered selftests.
1071 Start the debugged program stopping at the first instruction.
1074 Control display of debugging messages related to OpenRISC targets.
1076 set|show print type nested-type-limit
1077 Set and show the limit of nesting level for nested types that the
1078 type printer will show.
1080 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1083 * Safer/improved support for debugging with no debug info
1085 GDB no longer assumes functions with no debug information return
1088 This means that GDB now refuses to call such functions unless you
1089 tell it the function's type, by either casting the call to the
1090 declared return type, or by casting the function to a function
1091 pointer of the right type, and calling that:
1093 (gdb) p getenv ("PATH")
1094 'getenv' has unknown return type; cast the call to its declared return type
1095 (gdb) p (char *) getenv ("PATH")
1096 $1 = 0x7fffffffe "/usr/local/bin:/"...
1097 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1098 $2 = 0x7fffffffe "/usr/local/bin:/"...
1100 Similarly, GDB no longer assumes that global variables with no debug
1101 info have type 'int', and refuses to print the variable's value
1102 unless you tell it the variable's type:
1105 'var' has unknown type; cast it to its declared type
1109 * New native configurations
1111 FreeBSD/aarch64 aarch64*-*-freebsd*
1112 FreeBSD/arm arm*-*-freebsd*
1116 FreeBSD/aarch64 aarch64*-*-freebsd*
1117 FreeBSD/arm arm*-*-freebsd*
1118 OpenRISC ELF or1k*-*-elf
1120 * Removed targets and native configurations
1122 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1124 *** Changes in GDB 8.0
1126 * GDB now supports access to the PKU register on GNU/Linux. The register is
1127 added by the Memory Protection Keys for Userspace feature which will be
1128 available in future Intel CPUs.
1130 * GDB now supports C++11 rvalue references.
1134 ** New functions to start, stop and access a running btrace recording.
1135 ** Rvalue references are now supported in gdb.Type.
1137 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1140 * Building GDB and GDBserver now requires a C++11 compiler.
1142 For example, GCC 4.8 or later.
1144 It is no longer possible to build GDB or GDBserver with a C
1145 compiler. The --disable-build-with-cxx configure option has been
1148 * Building GDB and GDBserver now requires GNU make >= 3.81.
1150 It is no longer supported to build GDB or GDBserver with another
1151 implementation of the make program or an earlier version of GNU make.
1153 * Native debugging on MS-Windows supports command-line redirection
1155 Command-line arguments used for starting programs on MS-Windows can
1156 now include redirection symbols supported by native Windows shells,
1157 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1158 as "run", "start", and "set args", as well as the corresponding MI
1161 * Support for thread names on MS-Windows.
1163 GDB now catches and handles the special exception that programs
1164 running on MS-Windows use to assign names to threads in the
1167 * Support for Java programs compiled with gcj has been removed.
1169 * User commands now accept an unlimited number of arguments.
1170 Previously, only up to 10 was accepted.
1172 * The "eval" command now expands user-defined command arguments.
1174 This makes it easier to process a variable number of arguments:
1179 eval "print $arg%d", $i
1184 * Target descriptions can now describe registers for sparc32 and sparc64.
1186 * GDB now supports DWARF version 5 (debug information format).
1187 Its .debug_names index is not yet supported.
1189 * New native configurations
1191 FreeBSD/mips mips*-*-freebsd
1195 Synopsys ARC arc*-*-elf32
1196 FreeBSD/mips mips*-*-freebsd
1198 * Removed targets and native configurations
1200 Alpha running FreeBSD alpha*-*-freebsd*
1201 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1206 Erases all the flash memory regions reported by the target.
1208 maint print arc arc-instruction address
1209 Print internal disassembler information about instruction at a given address.
1213 set disassembler-options
1214 show disassembler-options
1215 Controls the passing of target specific information to the disassembler.
1216 If it is necessary to specify more than one disassembler option then
1217 multiple options can be placed together into a comma separated list.
1218 The default value is the empty string. Currently, the only supported
1219 targets are ARM, PowerPC and S/390.
1224 Erases all the flash memory regions reported by the target. This is
1225 equivalent to the CLI command flash-erase.
1227 -file-list-shared-libraries
1228 List the shared libraries in the program. This is
1229 equivalent to the CLI command "info shared".
1232 Catchpoints stopping the program when Ada exceptions are
1233 handled. This is equivalent to the CLI command "catch handlers".
1235 *** Changes in GDB 7.12
1237 * GDB and GDBserver now build with a C++ compiler by default.
1239 The --enable-build-with-cxx configure option is now enabled by
1240 default. One must now explicitly configure with
1241 --disable-build-with-cxx in order to build with a C compiler. This
1242 option will be removed in a future release.
1244 * GDBserver now supports recording btrace without maintaining an active
1247 * GDB now supports a negative repeat count in the 'x' command to examine
1248 memory backward from the given address. For example:
1251 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1252 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1253 (gdb) x/-5i 0x0000000000400580
1254 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1255 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1256 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1257 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1258 0x40057b <main(int, char**)+25>:
1259 callq 0x400536 <Func1(int, char const*)>
1261 * Fortran: Support structures with fields of dynamic types and
1262 arrays of dynamic types.
1264 * The symbol dumping maintenance commands have new syntax.
1265 maint print symbols [-pc address] [--] [filename]
1266 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1267 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1268 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1269 maint print msymbols [-objfile objfile] [--] [filename]
1271 * GDB now supports multibit bitfields and enums in target register
1274 * New Python-based convenience function $_as_string(val), which returns
1275 the textual representation of a value. This function is especially
1276 useful to obtain the text label of an enum value.
1278 * Intel MPX bound violation handling.
1280 Segmentation faults caused by a Intel MPX boundary violation
1281 now display the kind of violation (upper or lower), the memory
1282 address accessed and the memory bounds, along with the usual
1283 signal received and code location.
1287 Program received signal SIGSEGV, Segmentation fault
1288 Upper bound violation while accessing address 0x7fffffffc3b3
1289 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1290 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1292 * Rust language support.
1293 GDB now supports debugging programs written in the Rust programming
1294 language. See https://www.rust-lang.org/ for more information about
1297 * Support for running interpreters on specified input/output devices
1299 GDB now supports a new mechanism that allows frontends to provide
1300 fully featured GDB console views, as a better alternative to
1301 building such views on top of the "-interpreter-exec console"
1302 command. See the new "new-ui" command below. With that command,
1303 frontends can now start GDB in the traditional command-line mode
1304 running in an embedded terminal emulator widget, and create a
1305 separate MI interpreter running on a specified i/o device. In this
1306 way, GDB handles line editing, history, tab completion, etc. in the
1307 console all by itself, and the GUI uses the separate MI interpreter
1308 for its own control and synchronization, invisible to the command
1311 * The "catch syscall" command catches groups of related syscalls.
1313 The "catch syscall" command now supports catching a group of related
1314 syscalls using the 'group:' or 'g:' prefix.
1319 skip -gfile file-glob-pattern
1320 skip -function function
1321 skip -rfunction regular-expression
1322 A generalized form of the skip command, with new support for
1323 glob-style file names and regular expressions for function names.
1324 Additionally, a file spec and a function spec may now be combined.
1326 maint info line-table REGEXP
1327 Display the contents of GDB's internal line table data struture.
1330 Run any GDB unit tests that were compiled in.
1333 Start a new user interface instance running INTERP as interpreter,
1334 using the TTY file for input/output.
1338 ** gdb.Breakpoint objects have a new attribute "pending", which
1339 indicates whether the breakpoint is pending.
1340 ** Three new breakpoint-related events have been added:
1341 gdb.breakpoint_created, gdb.breakpoint_modified, and
1342 gdb.breakpoint_deleted.
1344 signal-event EVENTID
1345 Signal ("set") the given MS-Windows event object. This is used in
1346 conjunction with the Windows JIT debugging (AeDebug) support, where
1347 the OS suspends a crashing process until a debugger can attach to
1348 it. Resuming the crashing process, in order to debug it, is done by
1349 signalling an event.
1351 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1352 was added in GDBserver, including JIT compiling fast tracepoint's
1353 conditional expression bytecode into native code.
1355 * Support for various remote target protocols and ROM monitors has
1358 target m32rsdi Remote M32R debugging over SDI
1359 target mips MIPS remote debugging protocol
1360 target pmon PMON ROM monitor
1361 target ddb NEC's DDB variant of PMON for Vr4300
1362 target rockhopper NEC RockHopper variant of PMON
1363 target lsi LSI variant of PMO
1365 * Support for tracepoints and fast tracepoints on powerpc-linux,
1366 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1367 including JIT compiling fast tracepoint's conditional expression
1368 bytecode into native code.
1370 * MI async record =record-started now includes the method and format used for
1371 recording. For example:
1373 =record-started,thread-group="i1",method="btrace",format="bts"
1375 * MI async record =thread-selected now includes the frame field. For example:
1377 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1381 Andes NDS32 nds32*-*-elf
1383 *** Changes in GDB 7.11
1385 * GDB now supports debugging kernel-based threads on FreeBSD.
1387 * Per-inferior thread numbers
1389 Thread numbers are now per inferior instead of global. If you're
1390 debugging multiple inferiors, GDB displays thread IDs using a
1391 qualified INF_NUM.THR_NUM form. For example:
1395 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1396 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1397 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1398 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1400 As consequence, thread numbers as visible in the $_thread
1401 convenience variable and in Python's InferiorThread.num attribute
1402 are no longer unique between inferiors.
1404 GDB now maintains a second thread ID per thread, referred to as the
1405 global thread ID, which is the new equivalent of thread numbers in
1406 previous releases. See also $_gthread below.
1408 For backwards compatibility, MI's thread IDs always refer to global
1411 * Commands that accept thread IDs now accept the qualified
1412 INF_NUM.THR_NUM form as well. For example:
1415 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1418 * In commands that accept a list of thread IDs, you can now refer to
1419 all threads of an inferior using a star wildcard. GDB accepts
1420 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1421 refer to all threads of the current inferior. For example, "info
1424 * You can use "info threads -gid" to display the global thread ID of
1427 * The new convenience variable $_gthread holds the global number of
1430 * The new convenience variable $_inferior holds the number of the
1433 * GDB now displays the ID and name of the thread that hit a breakpoint
1434 or received a signal, if your program is multi-threaded. For
1437 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1438 Thread 1 "main" received signal SIGINT, Interrupt.
1440 * Record btrace now supports non-stop mode.
1442 * Support for tracepoints on aarch64-linux was added in GDBserver.
1444 * The 'record instruction-history' command now indicates speculative execution
1445 when using the Intel Processor Trace recording format.
1447 * GDB now allows users to specify explicit locations, bypassing
1448 the linespec parser. This feature is also available to GDB/MI
1451 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1452 GDB now is able to debug both AArch64 applications and ARM applications
1455 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1456 including JIT compiling fast tracepoint's conditional expression bytecode
1459 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1461 * "info threads", "info inferiors", "info display", "info checkpoints"
1462 and "maint info program-spaces" now list the corresponding items in
1463 ascending ID order, for consistency with all other "info" commands.
1465 * In Ada, the overloads selection menu has been enhanced to display the
1466 parameter types and the return types for the matching overloaded subprograms.
1470 maint set target-non-stop (on|off|auto)
1471 maint show target-non-stop
1472 Control whether GDB targets always operate in non-stop mode even if
1473 "set non-stop" is "off". The default is "auto", meaning non-stop
1474 mode is enabled if supported by the target.
1476 maint set bfd-sharing
1477 maint show bfd-sharing
1478 Control the reuse of bfd objects.
1481 show debug bfd-cache
1482 Control display of debugging info regarding bfd caching.
1486 Control display of debugging info regarding FreeBSD threads.
1488 set remote multiprocess-extensions-packet
1489 show remote multiprocess-extensions-packet
1490 Set/show the use of the remote protocol multiprocess extensions.
1492 set remote thread-events
1493 show remote thread-events
1494 Set/show the use of thread create/exit events.
1496 set ada print-signatures on|off
1497 show ada print-signatures"
1498 Control whether parameter types and return types are displayed in overloads
1499 selection menus. It is activaled (@code{on}) by default.
1503 Controls the maximum size of memory, in bytes, that GDB will
1504 allocate for value contents. Prevents incorrect programs from
1505 causing GDB to allocate overly large buffers. Default is 64k.
1507 * The "disassemble" command accepts a new modifier: /s.
1508 It prints mixed source+disassembly like /m with two differences:
1509 - disassembled instructions are now printed in program order, and
1510 - and source for all relevant files is now printed.
1511 The "/m" option is now considered deprecated: its "source-centric"
1512 output hasn't proved useful in practice.
1514 * The "record instruction-history" command accepts a new modifier: /s.
1515 It behaves exactly like /m and prints mixed source+disassembly.
1517 * The "set scheduler-locking" command supports a new mode "replay".
1518 It behaves like "off" in record mode and like "on" in replay mode.
1520 * Support for various ROM monitors has been removed:
1522 target dbug dBUG ROM monitor for Motorola ColdFire
1523 target picobug Motorola picobug monitor
1524 target dink32 DINK32 ROM monitor for PowerPC
1525 target m32r Renesas M32R/D ROM monitor
1526 target mon2000 mon2000 ROM monitor
1527 target ppcbug PPCBUG ROM monitor for PowerPC
1529 * Support for reading/writing memory and extracting values on architectures
1530 whose memory is addressable in units of any integral multiple of 8 bits.
1533 Allows to break when an Ada exception is handled.
1535 * New remote packets
1538 Indicates that an exec system call was executed.
1540 exec-events feature in qSupported
1541 The qSupported packet allows GDB to request support for exec
1542 events using the new 'gdbfeature' exec-event, and the qSupported
1543 response can contain the corresponding 'stubfeature'. Set and
1544 show commands can be used to display whether these features are enabled.
1547 Equivalent to interrupting with the ^C character, but works in
1550 thread created stop reason (T05 create:...)
1551 Indicates that the thread was just created and is stopped at entry.
1553 thread exit stop reply (w exitcode;tid)
1554 Indicates that the thread has terminated.
1557 Enables/disables thread create and exit event reporting. For
1558 example, this is used in non-stop mode when GDB stops a set of
1559 threads and synchronously waits for the their corresponding stop
1560 replies. Without exit events, if one of the threads exits, GDB
1561 would hang forever not knowing that it should no longer expect a
1562 stop for that same thread.
1565 Indicates that there are no resumed threads left in the target (all
1566 threads are stopped). The remote stub reports support for this stop
1567 reply to GDB's qSupported query.
1570 Enables/disables catching syscalls from the inferior process.
1571 The remote stub reports support for this packet to GDB's qSupported query.
1573 syscall_entry stop reason
1574 Indicates that a syscall was just called.
1576 syscall_return stop reason
1577 Indicates that a syscall just returned.
1579 * Extended-remote exec events
1581 ** GDB now has support for exec events on extended-remote Linux targets.
1582 For such targets with Linux kernels 2.5.46 and later, this enables
1583 follow-exec-mode and exec catchpoints.
1585 set remote exec-event-feature-packet
1586 show remote exec-event-feature-packet
1587 Set/show the use of the remote exec event feature.
1589 * Thread names in remote protocol
1591 The reply to qXfer:threads:read may now include a name attribute for each
1594 * Target remote mode fork and exec events
1596 ** GDB now has support for fork and exec events on target remote mode
1597 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1598 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1599 fork and exec catchpoints.
1601 * Remote syscall events
1603 ** GDB now has support for catch syscall on remote Linux targets,
1604 currently enabled on x86/x86_64 architectures.
1606 set remote catch-syscall-packet
1607 show remote catch-syscall-packet
1608 Set/show the use of the remote catch syscall feature.
1612 ** The -var-set-format command now accepts the zero-hexadecimal
1613 format. It outputs data in hexadecimal format with zero-padding on the
1618 ** gdb.InferiorThread objects have a new attribute "global_num",
1619 which refers to the thread's global thread ID. The existing
1620 "num" attribute now refers to the thread's per-inferior number.
1621 See "Per-inferior thread numbers" above.
1622 ** gdb.InferiorThread objects have a new attribute "inferior", which
1623 is the Inferior object the thread belongs to.
1625 *** Changes in GDB 7.10
1627 * Support for process record-replay and reverse debugging on aarch64*-linux*
1628 targets has been added. GDB now supports recording of A64 instruction set
1629 including advance SIMD instructions.
1631 * Support for Sun's version of the "stabs" debug file format has been removed.
1633 * GDB now honors the content of the file /proc/PID/coredump_filter
1634 (PID is the process ID) on GNU/Linux systems. This file can be used
1635 to specify the types of memory mappings that will be included in a
1636 corefile. For more information, please refer to the manual page of
1637 "core(5)". GDB also has a new command: "set use-coredump-filter
1638 on|off". It allows to set whether GDB will read the content of the
1639 /proc/PID/coredump_filter file when generating a corefile.
1641 * The "info os" command on GNU/Linux can now display information on
1643 "info os cpus" Listing of all cpus/cores on the system
1645 * GDB has two new commands: "set serial parity odd|even|none" and
1646 "show serial parity". These allows to set or show parity for the
1649 * The "info source" command now displays the producer string if it was
1650 present in the debug info. This typically includes the compiler version
1651 and may include things like its command line arguments.
1653 * The "info dll", an alias of the "info sharedlibrary" command,
1654 is now available on all platforms.
1656 * Directory names supplied to the "set sysroot" commands may be
1657 prefixed with "target:" to tell GDB to access shared libraries from
1658 the target system, be it local or remote. This replaces the prefix
1659 "remote:". The default sysroot has been changed from "" to
1660 "target:". "remote:" is automatically converted to "target:" for
1661 backward compatibility.
1663 * The system root specified by "set sysroot" will be prepended to the
1664 filename of the main executable (if reported to GDB as absolute by
1665 the operating system) when starting processes remotely, and when
1666 attaching to already-running local or remote processes.
1668 * GDB now supports automatic location and retrieval of executable
1669 files from remote targets. Remote debugging can now be initiated
1670 using only a "target remote" or "target extended-remote" command
1671 (no "set sysroot" or "file" commands are required). See "New remote
1674 * The "dump" command now supports verilog hex format.
1676 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1678 * On GNU/Linux, GDB and gdbserver are now able to access executable
1679 and shared library files without a "set sysroot" command when
1680 attaching to processes running in different mount namespaces from
1681 the debugger. This makes it possible to attach to processes in
1682 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1683 See "New remote packets" below.
1685 * The "tui reg" command now provides completion for all of the
1686 available register groups, including target specific groups.
1688 * The HISTSIZE environment variable is no longer read when determining
1689 the size of GDB's command history. GDB now instead reads the dedicated
1690 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1691 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1696 ** Memory ports can now be unbuffered.
1700 ** gdb.Objfile objects have a new attribute "username",
1701 which is the name of the objfile as specified by the user,
1702 without, for example, resolving symlinks.
1703 ** You can now write frame unwinders in Python.
1704 ** gdb.Type objects have a new method "optimized_out",
1705 returning optimized out gdb.Value instance of this type.
1706 ** gdb.Value objects have new methods "reference_value" and
1707 "const_value" which return a reference to the value and a
1708 "const" version of the value respectively.
1712 maint print symbol-cache
1713 Print the contents of the symbol cache.
1715 maint print symbol-cache-statistics
1716 Print statistics of symbol cache usage.
1718 maint flush-symbol-cache
1719 Flush the contents of the symbol cache.
1723 Start branch trace recording using Branch Trace Store (BTS) format.
1726 Evaluate expression by using the compiler and print result.
1730 Explicit commands for enabling and disabling tui mode.
1733 set mpx bound on i386 and amd64
1734 Support for bound table investigation on Intel MPX enabled applications.
1738 Start branch trace recording using Intel Processor Trace format.
1741 Print information about branch tracing internals.
1743 maint btrace packet-history
1744 Print the raw branch tracing data.
1746 maint btrace clear-packet-history
1747 Discard the stored raw branch tracing data.
1750 Discard all branch tracing data. It will be fetched and processed
1751 anew by the next "record" command.
1756 Renamed from "set debug dwarf2-die".
1757 show debug dwarf-die
1758 Renamed from "show debug dwarf2-die".
1760 set debug dwarf-read
1761 Renamed from "set debug dwarf2-read".
1762 show debug dwarf-read
1763 Renamed from "show debug dwarf2-read".
1765 maint set dwarf always-disassemble
1766 Renamed from "maint set dwarf2 always-disassemble".
1767 maint show dwarf always-disassemble
1768 Renamed from "maint show dwarf2 always-disassemble".
1770 maint set dwarf max-cache-age
1771 Renamed from "maint set dwarf2 max-cache-age".
1772 maint show dwarf max-cache-age
1773 Renamed from "maint show dwarf2 max-cache-age".
1775 set debug dwarf-line
1776 show debug dwarf-line
1777 Control display of debugging info regarding DWARF line processing.
1780 show max-completions
1781 Set the maximum number of candidates to be considered during
1782 completion. The default value is 200. This limit allows GDB
1783 to avoid generating large completion lists, the computation of
1784 which can cause the debugger to become temporarily unresponsive.
1786 set history remove-duplicates
1787 show history remove-duplicates
1788 Control the removal of duplicate history entries.
1790 maint set symbol-cache-size
1791 maint show symbol-cache-size
1792 Control the size of the symbol cache.
1794 set|show record btrace bts buffer-size
1795 Set and show the size of the ring buffer used for branch tracing in
1797 The obtained size may differ from the requested size. Use "info
1798 record" to see the obtained buffer size.
1800 set debug linux-namespaces
1801 show debug linux-namespaces
1802 Control display of debugging info regarding Linux namespaces.
1804 set|show record btrace pt buffer-size
1805 Set and show the size of the ring buffer used for branch tracing in
1806 Intel Processor Trace format.
1807 The obtained size may differ from the requested size. Use "info
1808 record" to see the obtained buffer size.
1810 maint set|show btrace pt skip-pad
1811 Set and show whether PAD packets are skipped when computing the
1814 * The command 'thread apply all' can now support new option '-ascending'
1815 to call its specified command for all threads in ascending order.
1817 * Python/Guile scripting
1819 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1820 special section named `.debug_gdb_scripts'.
1822 * New remote packets
1824 qXfer:btrace-conf:read
1825 Return the branch trace configuration for the current thread.
1827 Qbtrace-conf:bts:size
1828 Set the requested ring buffer size for branch tracing in BTS format.
1831 Enable Intel Procesor Trace-based branch tracing for the current
1832 process. The remote stub reports support for this packet to GDB's
1835 Qbtrace-conf:pt:size
1836 Set the requested ring buffer size for branch tracing in Intel Processor
1840 Indicates a memory breakpoint instruction was executed, irrespective
1841 of whether it was GDB that planted the breakpoint or the breakpoint
1842 is hardcoded in the program. This is required for correct non-stop
1846 Indicates the target stopped for a hardware breakpoint. This is
1847 required for correct non-stop mode operation.
1850 Return information about files on the remote system.
1852 qXfer:exec-file:read
1853 Return the full absolute name of the file that was executed to
1854 create a process running on the remote system.
1857 Select the filesystem on which vFile: operations with filename
1858 arguments will operate. This is required for GDB to be able to
1859 access files on remote targets where the remote stub does not
1860 share a common filesystem with the inferior(s).
1863 Indicates that a fork system call was executed.
1866 Indicates that a vfork system call was executed.
1868 vforkdone stop reason
1869 Indicates that a vfork child of the specified process has executed
1870 an exec or exit, allowing the vfork parent to resume execution.
1872 fork-events and vfork-events features in qSupported
1873 The qSupported packet allows GDB to request support for fork and
1874 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1875 and the qSupported response can contain the corresponding
1876 'stubfeatures'. Set and show commands can be used to display
1877 whether these features are enabled.
1879 * Extended-remote fork events
1881 ** GDB now has support for fork events on extended-remote Linux
1882 targets. For targets with Linux kernels 2.5.60 and later, this
1883 enables follow-fork-mode and detach-on-fork for both fork and
1884 vfork, as well as fork and vfork catchpoints.
1886 * The info record command now shows the recording format and the
1887 branch tracing configuration for the current thread when using
1888 the btrace record target.
1889 For the BTS format, it shows the ring buffer size.
1891 * GDB now has support for DTrace USDT (Userland Static Defined
1892 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1894 * GDB now supports access to vector registers on S/390 GNU/Linux
1897 * Removed command line options
1899 -xdb HP-UX XDB compatibility mode.
1901 * Removed targets and native configurations
1903 HP/PA running HP-UX hppa*-*-hpux*
1904 Itanium running HP-UX ia64-*-hpux*
1906 * New configure options
1909 This configure option allows the user to build GDB with support for
1910 Intel Processor Trace (default: auto). This requires libipt.
1912 --with-libipt-prefix=PATH
1913 Specify the path to the version of libipt that GDB should use.
1914 $PATH/include should contain the intel-pt.h header and
1915 $PATH/lib should contain the libipt.so library.
1917 *** Changes in GDB 7.9.1
1921 ** Xmethods can now specify a result type.
1923 *** Changes in GDB 7.9
1925 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1929 ** You can now access frame registers from Python scripts.
1930 ** New attribute 'producer' for gdb.Symtab objects.
1931 ** gdb.Objfile objects have a new attribute "progspace",
1932 which is the gdb.Progspace object of the containing program space.
1933 ** gdb.Objfile objects have a new attribute "owner".
1934 ** gdb.Objfile objects have a new attribute "build_id",
1935 which is the build ID generated when the file was built.
1936 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1937 ** A new event "gdb.clear_objfiles" has been added, triggered when
1938 selecting a new file to debug.
1939 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1940 ** New function gdb.lookup_objfile.
1942 New events which are triggered when GDB modifies the state of the
1945 ** gdb.events.inferior_call_pre: Function call is about to be made.
1946 ** gdb.events.inferior_call_post: Function call has just been made.
1947 ** gdb.events.memory_changed: A memory location has been altered.
1948 ** gdb.events.register_changed: A register has been altered.
1950 * New Python-based convenience functions:
1952 ** $_caller_is(name [, number_of_frames])
1953 ** $_caller_matches(regexp [, number_of_frames])
1954 ** $_any_caller_is(name [, number_of_frames])
1955 ** $_any_caller_matches(regexp [, number_of_frames])
1957 * GDB now supports the compilation and injection of source code into
1958 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1959 to compile the source code to object code, and if successful, inject
1960 and execute that code within the current context of the inferior.
1961 Currently the C language is supported. The commands used to
1962 interface with this new feature are:
1964 compile code [-raw|-r] [--] [source code]
1965 compile file [-raw|-r] filename
1969 demangle [-l language] [--] name
1970 Demangle "name" in the specified language, or the current language
1971 if elided. This command is renamed from the "maint demangle" command.
1972 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1973 as "maint demangler-warning".
1975 queue-signal signal-name-or-number
1976 Queue a signal to be delivered to the thread when it is resumed.
1978 add-auto-load-scripts-directory directory
1979 Add entries to the list of directories from which to load auto-loaded
1982 maint print user-registers
1983 List all currently available "user" registers.
1985 compile code [-r|-raw] [--] [source code]
1986 Compile, inject, and execute in the inferior the executable object
1987 code produced by compiling the provided source code.
1989 compile file [-r|-raw] filename
1990 Compile and inject into the inferior the executable object code
1991 produced by compiling the source code stored in the filename
1994 * On resume, GDB now always passes the signal the program had stopped
1995 for to the thread the signal was sent to, even if the user changed
1996 threads before resuming. Previously GDB would often (but not
1997 always) deliver the signal to the thread that happens to be current
2000 * Conversely, the "signal" command now consistently delivers the
2001 requested signal to the current thread. GDB now asks for
2002 confirmation if the program had stopped for a signal and the user
2003 switched threads meanwhile.
2005 * "breakpoint always-inserted" modes "off" and "auto" merged.
2007 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2008 won't remove breakpoints from the target until all threads stop,
2009 even in non-stop mode. The "auto" mode has been removed, and "off"
2010 is now the default mode.
2014 set debug symbol-lookup
2015 show debug symbol-lookup
2016 Control display of debugging info regarding symbol lookup.
2020 ** The -list-thread-groups command outputs an exit-code field for
2021 inferiors that have exited.
2025 MIPS SDE mips*-sde*-elf*
2029 Support for these obsolete configurations has been removed.
2031 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2032 SGI Irix-5.x mips-*-irix5*
2033 SGI Irix-6.x mips-*-irix6*
2034 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2035 VAX running Ultrix vax-*-ultrix*
2037 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2038 and "assf"), have been removed. Use the "sharedlibrary" command, or
2039 its alias "share", instead.
2041 *** Changes in GDB 7.8
2043 * New command line options
2046 This is an alias for the --data-directory option.
2048 * GDB supports printing and modifying of variable length automatic arrays
2049 as specified in ISO C99.
2051 * The ARM simulator now supports instruction level tracing
2052 with or without disassembly.
2056 GDB now has support for scripting using Guile. Whether this is
2057 available is determined at configure time.
2058 Guile version 2.0 or greater is required.
2059 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2061 * New commands (for set/show, see "New options" below)
2065 Invoke CODE by passing it to the Guile interpreter.
2069 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2071 info auto-load guile-scripts [regexp]
2072 Print the list of automatically loaded Guile scripts.
2074 * The source command is now capable of sourcing Guile scripts.
2075 This feature is dependent on the debugger being built with Guile support.
2079 set print symbol-loading (off|brief|full)
2080 show print symbol-loading
2081 Control whether to print informational messages when loading symbol
2082 information for a file. The default is "full", but when debugging
2083 programs with large numbers of shared libraries the amount of output
2084 becomes less useful.
2086 set guile print-stack (none|message|full)
2087 show guile print-stack
2088 Show a stack trace when an error is encountered in a Guile script.
2090 set auto-load guile-scripts (on|off)
2091 show auto-load guile-scripts
2092 Control auto-loading of Guile script files.
2094 maint ada set ignore-descriptive-types (on|off)
2095 maint ada show ignore-descriptive-types
2096 Control whether the debugger should ignore descriptive types in Ada
2097 programs. The default is not to ignore the descriptive types. See
2098 the user manual for more details on descriptive types and the intended
2099 usage of this option.
2101 set auto-connect-native-target
2103 Control whether GDB is allowed to automatically connect to the
2104 native target for the run, attach, etc. commands when not connected
2105 to any target yet. See also "target native" below.
2107 set record btrace replay-memory-access (read-only|read-write)
2108 show record btrace replay-memory-access
2109 Control what memory accesses are allowed during replay.
2111 maint set target-async (on|off)
2112 maint show target-async
2113 This controls whether GDB targets operate in synchronous or
2114 asynchronous mode. Normally the default is asynchronous, if it is
2115 available; but this can be changed to more easily debug problems
2116 occurring only in synchronous mode.
2118 set mi-async (on|off)
2120 Control whether MI asynchronous mode is preferred. This supersedes
2121 "set target-async" of previous GDB versions.
2123 * "set target-async" is deprecated as a CLI option and is now an alias
2124 for "set mi-async" (only puts MI into async mode).
2126 * Background execution commands (e.g., "c&", "s&", etc.) are now
2127 possible ``out of the box'' if the target supports them. Previously
2128 the user would need to explicitly enable the possibility with the
2129 "set target-async on" command.
2131 * New features in the GDB remote stub, GDBserver
2133 ** New option --debug-format=option1[,option2,...] allows one to add
2134 additional text to each output. At present only timestamps
2135 are supported: --debug-format=timestamps.
2136 Timestamps can also be turned on with the
2137 "monitor set debug-format timestamps" command from GDB.
2139 * The 'record instruction-history' command now starts counting instructions
2140 at one. This also affects the instruction ranges reported by the
2141 'record function-call-history' command when given the /i modifier.
2143 * The command 'record function-call-history' supports a new modifier '/c' to
2144 indent the function names based on their call stack depth.
2145 The fields for the '/i' and '/l' modifier have been reordered.
2146 The source line range is now prefixed with 'at'.
2147 The instruction range is now prefixed with 'inst'.
2148 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2149 "record instruction-history" and "list" commands.
2151 * The ranges given as arguments to the 'record function-call-history' and
2152 'record instruction-history' commands are now inclusive.
2154 * The btrace record target now supports the 'record goto' command.
2155 For locations inside the execution trace, the back trace is computed
2156 based on the information stored in the execution trace.
2158 * The btrace record target supports limited reverse execution and replay.
2159 The target does not record data and therefore does not allow reading
2160 memory or registers.
2162 * The "catch syscall" command now works on s390*-linux* targets.
2164 * The "compare-sections" command is no longer specific to target
2165 remote. It now works with all targets.
2167 * All native targets are now consistently called "native".
2168 Consequently, the "target child", "target GNU", "target djgpp",
2169 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2170 commands have been replaced with "target native". The QNX/NTO port
2171 leaves the "procfs" target in place and adds a "native" target for
2172 consistency with other ports. The impact on users should be minimal
2173 as these commands previously either throwed an error, or were
2174 no-ops. The target's name is visible in the output of the following
2175 commands: "help target", "info target", "info files", "maint print
2178 * The "target native" command now connects to the native target. This
2179 can be used to launch native programs even when "set
2180 auto-connect-native-target" is set to off.
2182 * GDB now supports access to Intel MPX registers on GNU/Linux.
2184 * Support for Intel AVX-512 registers on GNU/Linux.
2185 Support displaying and modifying Intel AVX-512 registers
2186 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2188 * New remote packets
2190 qXfer:btrace:read's annex
2191 The qXfer:btrace:read packet supports a new annex 'delta' to read
2192 branch trace incrementally.
2196 ** Valid Python operations on gdb.Value objects representing
2197 structs/classes invoke the corresponding overloaded operators if
2199 ** New `Xmethods' feature in the Python API. Xmethods are
2200 additional methods or replacements for existing methods of a C++
2201 class. This feature is useful for those cases where a method
2202 defined in C++ source code could be inlined or optimized out by
2203 the compiler, making it unavailable to GDB.
2206 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2208 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2209 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2210 its alias "share", instead.
2212 * The commands "set remotebaud" and "show remotebaud" are no longer
2213 supported. Use "set serial baud" and "show serial baud" (respectively)
2218 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2219 target-async". The latter is left as a deprecated alias of the
2220 former for backward compatibility. If the target supports it,
2221 CLI background execution commands are now always possible by
2222 default, independently of whether the frontend stated a
2223 preference for asynchronous execution with "-gdb-set mi-async".
2224 Previously "-gdb-set target-async off" affected both MI execution
2225 commands and CLI execution commands.
2227 *** Changes in GDB 7.7
2229 * Improved support for process record-replay and reverse debugging on
2230 arm*-linux* targets. Support for thumb32 and syscall instruction
2231 recording has been added.
2233 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2235 * GDB now supports Fission DWP file format version 2.
2236 http://gcc.gnu.org/wiki/DebugFission
2238 * New convenience function "$_isvoid", to check whether an expression
2239 is void. A void expression is an expression where the type of the
2240 result is "void". For example, some convenience variables may be
2241 "void" when evaluated (e.g., "$_exitcode" before the execution of
2242 the program being debugged; or an undefined convenience variable).
2243 Another example, when calling a function whose return type is
2246 * The "maintenance print objfiles" command now takes an optional regexp.
2248 * The "catch syscall" command now works on arm*-linux* targets.
2250 * GDB now consistently shows "<not saved>" when printing values of
2251 registers the debug info indicates have not been saved in the frame
2252 and there's nowhere to retrieve them from
2253 (callee-saved/call-clobbered registers):
2258 (gdb) info registers rax
2261 Before, the former would print "<optimized out>", and the latter
2262 "*value not available*".
2264 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2269 ** Frame filters and frame decorators have been added.
2270 ** Temporary breakpoints are now supported.
2271 ** Line tables representation has been added.
2272 ** New attribute 'parent_type' for gdb.Field objects.
2273 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2274 ** New attribute 'name' for gdb.Type objects.
2278 Nios II ELF nios2*-*-elf
2279 Nios II GNU/Linux nios2*-*-linux
2280 Texas Instruments MSP430 msp430*-*-elf
2282 * Removed native configurations
2284 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2285 been removed. ELF variants of these configurations are kept supported.
2287 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2288 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2289 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2290 i[34567]86-*-openbsd3.[0-3]
2291 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2292 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2293 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2297 Like "catch throw", but catches a re-thrown exception.
2298 maint check-psymtabs
2299 Renamed from old "maint check-symtabs".
2301 Perform consistency checks on symtabs.
2302 maint expand-symtabs
2303 Expand symtabs matching an optional regexp.
2306 Display the details of GDB configure-time options.
2308 maint set|show per-command
2309 maint set|show per-command space
2310 maint set|show per-command time
2311 maint set|show per-command symtab
2312 Enable display of per-command gdb resource usage.
2314 remove-symbol-file FILENAME
2315 remove-symbol-file -a ADDRESS
2316 Remove a symbol file added via add-symbol-file. The file to remove
2317 can be identified by its filename or by an address that lies within
2318 the boundaries of this symbol file in memory.
2321 info exceptions REGEXP
2322 Display the list of Ada exceptions defined in the program being
2323 debugged. If provided, only the exceptions whose names match REGEXP
2328 set debug symfile off|on
2330 Control display of debugging info regarding reading symbol files and
2331 symbol tables within those files
2333 set print raw frame-arguments
2334 show print raw frame-arguments
2335 Set/show whether to print frame arguments in raw mode,
2336 disregarding any defined pretty-printers.
2338 set remote trace-status-packet
2339 show remote trace-status-packet
2340 Set/show the use of remote protocol qTStatus packet.
2344 Control display of debugging messages related to Nios II targets.
2348 Control whether target-assisted range stepping is enabled.
2350 set startup-with-shell
2351 show startup-with-shell
2352 Specifies whether Unix child processes are started via a shell or
2357 Use the target memory cache for accesses to the code segment. This
2358 improves performance of remote debugging (particularly disassembly).
2360 * You can now use a literal value 'unlimited' for options that
2361 interpret 0 or -1 as meaning "unlimited". E.g., "set
2362 trace-buffer-size unlimited" is now an alias for "set
2363 trace-buffer-size -1" and "set height unlimited" is now an alias for
2366 * The "set debug symtab-create" debugging option of GDB has been changed to
2367 accept a verbosity level. 0 means "off", 1 provides basic debugging
2368 output, and values of 2 or greater provides more verbose output.
2370 * New command-line options
2372 Display the details of GDB configure-time options.
2374 * The command 'tsave' can now support new option '-ctf' to save trace
2375 buffer in Common Trace Format.
2377 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2380 * GDB now implements the the C++ 'typeid' operator.
2382 * The new convenience variable $_exception holds the exception being
2383 thrown or caught at an exception-related catchpoint.
2385 * The exception-related catchpoints, like "catch throw", now accept a
2386 regular expression which can be used to filter exceptions by type.
2388 * The new convenience variable $_exitsignal is automatically set to
2389 the terminating signal number when the program being debugged dies
2390 due to an uncaught signal.
2394 ** All MI commands now accept an optional "--language" option.
2395 Support for this feature can be verified by using the "-list-features"
2396 command, which should contain "language-option".
2398 ** The new command -info-gdb-mi-command allows the user to determine
2399 whether a GDB/MI command is supported or not.
2401 ** The "^error" result record returned when trying to execute an undefined
2402 GDB/MI command now provides a variable named "code" whose content is the
2403 "undefined-command" error code. Support for this feature can be verified
2404 by using the "-list-features" command, which should contain
2405 "undefined-command-error-code".
2407 ** The -trace-save MI command can optionally save trace buffer in Common
2410 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2412 ** The command -data-list-register-values now accepts an optional
2413 "--skip-unavailable" option. When used, only the available registers
2416 ** The new command -trace-frame-collected dumps collected variables,
2417 computed expressions, tvars, memory and registers in a traceframe.
2419 ** The commands -stack-list-locals, -stack-list-arguments and
2420 -stack-list-variables now accept an option "--skip-unavailable".
2421 When used, only the available locals or arguments are displayed.
2423 ** The -exec-run command now accepts an optional "--start" option.
2424 When used, the command follows the same semantics as the "start"
2425 command, stopping the program's execution at the start of its
2426 main subprogram. Support for this feature can be verified using
2427 the "-list-features" command, which should contain
2428 "exec-run-start-option".
2430 ** The new commands -catch-assert and -catch-exceptions insert
2431 catchpoints stopping the program when Ada exceptions are raised.
2433 ** The new command -info-ada-exceptions provides the equivalent of
2434 the new "info exceptions" command.
2436 * New system-wide configuration scripts
2437 A GDB installation now provides scripts suitable for use as system-wide
2438 configuration scripts for the following systems:
2442 * GDB now supports target-assigned range stepping with remote targets.
2443 This improves the performance of stepping source lines by reducing
2444 the number of control packets from/to GDB. See "New remote packets"
2447 * GDB now understands the element 'tvar' in the XML traceframe info.
2448 It has the id of the collected trace state variables.
2450 * On S/390 targets that provide the transactional-execution feature,
2451 the program interruption transaction diagnostic block (TDB) is now
2452 represented as a number of additional "registers" in GDB.
2454 * New remote packets
2458 The vCont packet supports a new 'r' action, that tells the remote
2459 stub to step through an address range itself, without GDB
2460 involvemement at each single-step.
2462 qXfer:libraries-svr4:read's annex
2463 The previously unused annex of the qXfer:libraries-svr4:read packet
2464 is now used to support passing an argument list. The remote stub
2465 reports support for this argument list to GDB's qSupported query.
2466 The defined arguments are "start" and "prev", used to reduce work
2467 necessary for library list updating, resulting in significant
2470 * New features in the GDB remote stub, GDBserver
2472 ** GDBserver now supports target-assisted range stepping. Currently
2473 enabled on x86/x86_64 GNU/Linux targets.
2475 ** GDBserver now adds element 'tvar' in the XML in the reply to
2476 'qXfer:traceframe-info:read'. It has the id of the collected
2477 trace state variables.
2479 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2482 * New 'z' formatter for printing and examining memory, this displays the
2483 value as hexadecimal zero padded on the left to the size of the type.
2485 * GDB can now use Windows x64 unwinding data.
2487 * The "set remotebaud" command has been replaced by "set serial baud".
2488 Similarly, "show remotebaud" has been replaced by "show serial baud".
2489 The "set remotebaud" and "show remotebaud" commands are still available
2490 to provide backward compatibility with older versions of GDB.
2492 *** Changes in GDB 7.6
2494 * Target record has been renamed to record-full.
2495 Record/replay is now enabled with the "record full" command.
2496 This also affects settings that are associated with full record/replay
2497 that have been moved from "set/show record" to "set/show record full":
2499 set|show record full insn-number-max
2500 set|show record full stop-at-limit
2501 set|show record full memory-query
2503 * A new record target "record-btrace" has been added. The new target
2504 uses hardware support to record the control-flow of a process. It
2505 does not support replaying the execution, but it implements the
2506 below new commands for investigating the recorded execution log.
2507 This new recording method can be enabled using:
2511 The "record-btrace" target is only available on Intel Atom processors
2512 and requires a Linux kernel 2.6.32 or later.
2514 * Two new commands have been added for record/replay to give information
2515 about the recorded execution without having to replay the execution.
2516 The commands are only supported by "record btrace".
2518 record instruction-history prints the execution history at
2519 instruction granularity
2521 record function-call-history prints the execution history at
2522 function granularity
2524 * New native configurations
2526 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2527 FreeBSD/powerpc powerpc*-*-freebsd
2528 x86_64/Cygwin x86_64-*-cygwin*
2529 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2533 ARM AArch64 aarch64*-*-elf
2534 ARM AArch64 GNU/Linux aarch64*-*-linux
2535 Lynx 178 PowerPC powerpc-*-lynx*178
2536 x86_64/Cygwin x86_64-*-cygwin*
2537 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2539 * If the configured location of system.gdbinit file (as given by the
2540 --with-system-gdbinit option at configure time) is in the
2541 data-directory (as specified by --with-gdb-datadir at configure
2542 time) or in one of its subdirectories, then GDB will look for the
2543 system-wide init file in the directory specified by the
2544 --data-directory command-line option.
2546 * New command line options:
2548 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2549 other initialization files, unlike -nx which disables all of them.
2551 * Removed command line options
2553 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2556 * The 'ptype' and 'whatis' commands now accept an argument to control
2559 * 'info proc' now works on some core files.
2563 ** Vectors can be created with gdb.Type.vector.
2565 ** Python's atexit.register now works in GDB.
2567 ** Types can be pretty-printed via a Python API.
2569 ** Python 3 is now supported (in addition to Python 2.4 or later)
2571 ** New class gdb.Architecture exposes GDB's internal representation
2572 of architecture in the Python API.
2574 ** New method Frame.architecture returns the gdb.Architecture object
2575 corresponding to the frame's architecture.
2577 * New Python-based convenience functions:
2579 ** $_memeq(buf1, buf2, length)
2580 ** $_streq(str1, str2)
2582 ** $_regex(str, regex)
2584 * The 'cd' command now defaults to using '~' (the home directory) if not
2587 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2588 default for GCC since November 2000.
2590 * The command 'forward-search' can now be abbreviated as 'fo'.
2592 * The command 'info tracepoints' can now display 'installed on target'
2593 or 'not installed on target' for each non-pending location of tracepoint.
2595 * New configure options
2597 --enable-libmcheck/--disable-libmcheck
2598 By default, development versions are built with -lmcheck on hosts
2599 that support it, in order to help track memory corruption issues.
2600 Release versions, on the other hand, are built without -lmcheck
2601 by default. The --enable-libmcheck/--disable-libmcheck configure
2602 options allow the user to override that default.
2603 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2604 This configure option allows the user to build GDB with
2605 libbabeltrace using which GDB can read Common Trace Format data.
2607 * New commands (for set/show, see "New options" below)
2610 Catch signals. This is similar to "handle", but allows commands and
2611 conditions to be attached.
2614 List the BFDs known to GDB.
2616 python-interactive [command]
2618 Start a Python interactive prompt, or evaluate the optional command
2619 and print the result of expressions.
2622 "py" is a new alias for "python".
2624 enable type-printer [name]...
2625 disable type-printer [name]...
2626 Enable or disable type printers.
2630 ** For the Renesas Super-H architecture, the "regs" command has been removed
2631 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2636 set print type methods (on|off)
2637 show print type methods
2638 Control whether method declarations are displayed by "ptype".
2639 The default is to show them.
2641 set print type typedefs (on|off)
2642 show print type typedefs
2643 Control whether typedef definitions are displayed by "ptype".
2644 The default is to show them.
2646 set filename-display basename|relative|absolute
2647 show filename-display
2648 Control the way in which filenames is displayed.
2649 The default is "relative", which preserves previous behavior.
2651 set trace-buffer-size
2652 show trace-buffer-size
2653 Request target to change the size of trace buffer.
2655 set remote trace-buffer-size-packet auto|on|off
2656 show remote trace-buffer-size-packet
2657 Control the use of the remote protocol `QTBuffer:size' packet.
2661 Control display of debugging messages related to ARM AArch64.
2664 set debug coff-pe-read
2665 show debug coff-pe-read
2666 Control display of debugging messages related to reading of COFF/PE
2671 Control display of debugging messages related to Mach-O symbols
2674 set debug notification
2675 show debug notification
2676 Control display of debugging info for async remote notification.
2680 ** Command parameter changes are now notified using new async record
2681 "=cmd-param-changed".
2682 ** Trace frame changes caused by command "tfind" are now notified using
2683 new async record "=traceframe-changed".
2684 ** The creation, deletion and modification of trace state variables
2685 are now notified using new async records "=tsv-created",
2686 "=tsv-deleted" and "=tsv-modified".
2687 ** The start and stop of process record are now notified using new
2688 async record "=record-started" and "=record-stopped".
2689 ** Memory changes are now notified using new async record
2691 ** The data-disassemble command response will include a "fullname" field
2692 containing the absolute file name when source has been requested.
2693 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2694 command, to allow pattern filling of memory areas.
2695 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2696 library load/unload events.
2697 ** The response to breakpoint commands and breakpoint async records
2698 includes an "installed" field containing a boolean state about each
2699 non-pending tracepoint location is whether installed on target or not.
2700 ** Output of the "-trace-status" command includes a "trace-file" field
2701 containing the name of the trace file being examined. This field is
2702 optional, and only present when examining a trace file.
2703 ** The "fullname" field is now always present along with the "file" field,
2704 even if the file cannot be found by GDB.
2706 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2707 You must have the LZMA library available when configuring GDB for this
2708 feature to be enabled. For more information, see:
2709 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2711 * New remote packets
2714 Set the size of trace buffer. The remote stub reports support for this
2715 packet to gdb's qSupported query.
2718 Enable Branch Trace Store (BTS)-based branch tracing for the current
2719 thread. The remote stub reports support for this packet to gdb's
2723 Disable branch tracing for the current thread. The remote stub reports
2724 support for this packet to gdb's qSupported query.
2727 Read the traced branches for the current thread. The remote stub
2728 reports support for this packet to gdb's qSupported query.
2730 *** Changes in GDB 7.5
2732 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2733 for more x32 ABI info.
2735 * GDB now supports access to MIPS DSP registers on Linux targets.
2737 * GDB now supports debugging microMIPS binaries.
2739 * The "info os" command on GNU/Linux can now display information on
2740 several new classes of objects managed by the operating system:
2741 "info os procgroups" lists process groups
2742 "info os files" lists file descriptors
2743 "info os sockets" lists internet-domain sockets
2744 "info os shm" lists shared-memory regions
2745 "info os semaphores" lists semaphores
2746 "info os msg" lists message queues
2747 "info os modules" lists loaded kernel modules
2749 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2750 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2751 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2752 options and inspect the probe arguments using the new $_probe_arg family
2753 of convenience variables. You can obtain more information about SystemTap
2754 in <http://sourceware.org/systemtap/>.
2756 * GDB now supports reversible debugging on ARM, it allows you to
2757 debug basic ARM and THUMB instructions, and provides
2758 record/replay support.
2760 * The option "symbol-reloading" has been deleted as it is no longer used.
2764 ** GDB commands implemented in Python can now be put in command class
2767 ** The "maint set python print-stack on|off" is now deleted.
2769 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2770 apply "flag enum"-style pretty-printing to any enum.
2772 ** gdb.lookup_symbol can now work when there is no current frame.
2774 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2775 the source at which the symbol was defined.
2777 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2778 method 'value'. The former indicates whether the symbol needs a
2779 frame in order to compute its value, and the latter computes the
2782 ** A new method 'referenced_value' on gdb.Value objects which can
2783 dereference pointer as well as C++ reference values.
2785 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2786 which return the global and static blocks (as gdb.Block objects),
2787 of the underlying symbol table, respectively.
2789 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2790 object associated with a PC value.
2792 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2793 of the address range occupied by code for the current source line.
2795 * Go language support.
2796 GDB now supports debugging programs written in the Go programming
2799 * GDBserver now supports stdio connections.
2800 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2802 * The binary "gdbtui" can no longer be built or installed.
2803 Use "gdb -tui" instead.
2805 * GDB will now print "flag" enums specially. A flag enum is one where
2806 all the enumerator values have no bits in common when pairwise
2807 "and"ed. When printing a value whose type is a flag enum, GDB will
2808 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2809 (gdb) print (enum E) 3
2812 * The filename part of a linespec will now match trailing components
2813 of a source file name. For example, "break gcc/expr.c:1000" will
2814 now set a breakpoint in build/gcc/expr.c, but not
2815 build/libcpp/expr.c.
2817 * The "info proc" and "generate-core-file" commands will now also
2818 work on remote targets connected to GDBserver on Linux.
2820 * The command "info catch" has been removed. It has been disabled
2821 since December 2007.
2823 * The "catch exception" and "catch assert" commands now accept
2824 a condition at the end of the command, much like the "break"
2825 command does. For instance:
2827 (gdb) catch exception Constraint_Error if Barrier = True
2829 Previously, it was possible to add a condition to such catchpoints,
2830 but it had to be done as a second step, after the catchpoint had been
2831 created, using the "condition" command.
2833 * The "info static-tracepoint-marker" command will now also work on
2834 native Linux targets with in-process agent.
2836 * GDB can now set breakpoints on inlined functions.
2838 * The .gdb_index section has been updated to include symbols for
2839 inlined functions. GDB will ignore older .gdb_index sections by
2840 default, which could cause symbol files to be loaded more slowly
2841 until their .gdb_index sections can be recreated. The new command
2842 "set use-deprecated-index-sections on" will cause GDB to use any older
2843 .gdb_index sections it finds. This will restore performance, but the
2844 ability to set breakpoints on inlined functions will be lost in symbol
2845 files with older .gdb_index sections.
2847 The .gdb_index section has also been updated to record more information
2848 about each symbol. This speeds up the "info variables", "info functions"
2849 and "info types" commands when used with programs having the .gdb_index
2850 section, as well as speeding up debugging with shared libraries using
2851 the .gdb_index section.
2853 * Ada support for GDB/MI Variable Objects has been added.
2855 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2860 ** New command -info-os is the MI equivalent of "info os".
2862 ** Output logs ("set logging" and related) now include MI output.
2866 ** "set use-deprecated-index-sections on|off"
2867 "show use-deprecated-index-sections on|off"
2868 Controls the use of deprecated .gdb_index sections.
2870 ** "catch load" and "catch unload" can be used to stop when a shared
2871 library is loaded or unloaded, respectively.
2873 ** "enable count" can be used to auto-disable a breakpoint after
2876 ** "info vtbl" can be used to show the virtual method tables for
2877 C++ and Java objects.
2879 ** "explore" and its sub commands "explore value" and "explore type"
2880 can be used to recursively explore values and types of
2881 expressions. These commands are available only if GDB is
2882 configured with '--with-python'.
2884 ** "info auto-load" shows status of all kinds of auto-loaded files,
2885 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2886 sequences of commands files, "info auto-load python-scripts"
2887 shows status of auto-loading Python script files,
2888 "info auto-load local-gdbinit" shows status of loading init file
2889 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2890 status of inferior specific thread debugging shared library loading.
2892 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2893 and "show auto-load-scripts" commands have been deprecated, use their
2894 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2895 and "show auto-load python-scripts" counterparts instead.
2897 ** "dprintf location,format,args..." creates a dynamic printf, which
2898 is basically a breakpoint that does a printf and immediately
2899 resumes your program's execution, so it is like a printf that you
2900 can insert dynamically at runtime instead of at compiletime.
2902 ** "set print symbol"
2904 Controls whether GDB attempts to display the symbol, if any,
2905 corresponding to addresses it prints. This defaults to "on", but
2906 you can set it to "off" to restore GDB's previous behavior.
2908 * Deprecated commands
2910 ** For the Renesas Super-H architecture, the "regs" command has been
2911 deprecated, and "info all-registers" should be used instead.
2915 Renesas RL78 rl78-*-elf
2916 HP OpenVMS ia64 ia64-hp-openvms*
2918 * GDBserver supports evaluation of breakpoint conditions. When
2919 support is advertised by GDBserver, GDB may be told to send the
2920 breakpoint conditions in bytecode form to GDBserver. GDBserver
2921 will only report the breakpoint trigger to GDB when its condition
2926 set mips compression
2927 show mips compression
2928 Select the compressed ISA encoding used in functions that have no symbol
2929 information available. The encoding can be set to either of:
2932 and is updated automatically from ELF file flags if available.
2934 set breakpoint condition-evaluation
2935 show breakpoint condition-evaluation
2936 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2937 GDBserver ("target"). Default option "auto" chooses the most efficient
2939 This option can improve debugger efficiency depending on the speed of the
2943 Disable auto-loading globally.
2946 Show auto-loading setting of all kinds of auto-loaded files.
2948 set auto-load gdb-scripts on|off
2949 show auto-load gdb-scripts
2950 Control auto-loading of GDB canned sequences of commands files.
2952 set auto-load python-scripts on|off
2953 show auto-load python-scripts
2954 Control auto-loading of Python script files.
2956 set auto-load local-gdbinit on|off
2957 show auto-load local-gdbinit
2958 Control loading of init file (.gdbinit) from current directory.
2960 set auto-load libthread-db on|off
2961 show auto-load libthread-db
2962 Control auto-loading of inferior specific thread debugging shared library.
2964 set auto-load scripts-directory <dir1>[:<dir2>...]
2965 show auto-load scripts-directory
2966 Set a list of directories from which to load auto-loaded scripts.
2967 Automatically loaded Python scripts and GDB scripts are located in one
2968 of the directories listed by this option.
2969 The delimiter (':' above) may differ according to the host platform.
2971 set auto-load safe-path <dir1>[:<dir2>...]
2972 show auto-load safe-path
2973 Set a list of directories from which it is safe to auto-load files.
2974 The delimiter (':' above) may differ according to the host platform.
2976 set debug auto-load on|off
2977 show debug auto-load
2978 Control display of debugging info for auto-loading the files above.
2980 set dprintf-style gdb|call|agent
2982 Control the way in which a dynamic printf is performed; "gdb"
2983 requests a GDB printf command, while "call" causes dprintf to call a
2984 function in the inferior. "agent" requests that the target agent
2985 (such as GDBserver) do the printing.
2987 set dprintf-function <expr>
2988 show dprintf-function
2989 set dprintf-channel <expr>
2990 show dprintf-channel
2991 Set the function and optional first argument to the call when using
2992 the "call" style of dynamic printf.
2994 set disconnected-dprintf on|off
2995 show disconnected-dprintf
2996 Control whether agent-style dynamic printfs continue to be in effect
2997 after GDB disconnects.
2999 * New configure options
3001 --with-auto-load-dir
3002 Configure default value for the 'set auto-load scripts-directory'
3003 setting above. It defaults to '$debugdir:$datadir/auto-load',
3004 $debugdir representing global debugging info directories (available
3005 via 'show debug-file-directory') and $datadir representing GDB's data
3006 directory (available via 'show data-directory').
3008 --with-auto-load-safe-path
3009 Configure default value for the 'set auto-load safe-path' setting
3010 above. It defaults to the --with-auto-load-dir setting.
3012 --without-auto-load-safe-path
3013 Set 'set auto-load safe-path' to '/', effectively disabling this
3016 * New remote packets
3018 z0/z1 conditional breakpoints extension
3020 The z0/z1 breakpoint insertion packets have been extended to carry
3021 a list of conditional expressions over to the remote stub depending on the
3022 condition evaluation mode. The use of this extension can be controlled
3023 via the "set remote conditional-breakpoints-packet" command.
3027 Specify the signals which the remote stub may pass to the debugged
3028 program without GDB involvement.
3030 * New command line options
3032 --init-command=FILE, -ix Like --command, -x but execute it
3033 before loading inferior.
3034 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3035 execute it before loading inferior.
3037 *** Changes in GDB 7.4
3039 * GDB now handles ambiguous linespecs more consistently; the existing
3040 FILE:LINE support has been expanded to other types of linespecs. A
3041 breakpoint will now be set on all matching locations in all
3042 inferiors, and locations will be added or removed according to
3045 * GDB now allows you to skip uninteresting functions and files when
3046 stepping with the "skip function" and "skip file" commands.
3048 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3049 and "show remote hardware-watchpoint-length-limit". These allows to
3050 set or show the maximum length limit (in bytes) of a remote
3051 target hardware watchpoint.
3053 This allows e.g. to use "unlimited" hardware watchpoints with the
3054 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3055 watchpoints are slower than real hardware watchpoints but are
3056 significantly faster than gdb software watchpoints.
3060 ** The register_pretty_printer function in module gdb.printing now takes
3061 an optional `replace' argument. If True, the new printer replaces any
3064 ** The "maint set python print-stack on|off" command has been
3065 deprecated and will be deleted in GDB 7.5.
3066 A new command: "set python print-stack none|full|message" has
3067 replaced it. Additionally, the default for "print-stack" is
3068 now "message", which just prints the error message without
3071 ** A prompt substitution hook (prompt_hook) is now available to the
3074 ** A new Python module, gdb.prompt has been added to the GDB Python
3075 modules library. This module provides functionality for
3076 escape sequences in prompts (used by set/show
3077 extended-prompt). These escape sequences are replaced by their
3078 corresponding value.
3080 ** Python commands and convenience-functions located in
3081 'data-directory'/python/gdb/command and
3082 'data-directory'/python/gdb/function are now automatically loaded
3085 ** Blocks now provide four new attributes. global_block and
3086 static_block will return the global and static blocks
3087 respectively. is_static and is_global are boolean attributes
3088 that indicate if the block is one of those two types.
3090 ** Symbols now provide the "type" attribute, the type of the symbol.
3092 ** The "gdb.breakpoint" function has been deprecated in favor of
3095 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3096 of a function. This class is based on the "finish" command
3097 available in the CLI.
3099 ** Type objects for struct and union types now allow access to
3100 the fields using standard Python dictionary (mapping) methods.
3101 For example, "some_type['myfield']" now works, as does
3102 "some_type.items()".
3104 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3107 ** A new function, "deep_items" has been added to the gdb.types
3108 module in the GDB Python modules library. This function returns
3109 an iterator over the fields of a struct or union type. Unlike
3110 the standard Python "iteritems" method, it will recursively traverse
3111 any anonymous fields.
3115 ** "*stopped" events can report several new "reason"s, such as
3118 ** Breakpoint changes are now notified using new async records, like
3119 "=breakpoint-modified".
3121 ** New command -ada-task-info.
3123 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3124 $sdir specifies the default system locations of shared libraries.
3125 $pdir specifies the directory where the libpthread used by the application
3128 GDB no longer looks in $sdir and $pdir after it has searched the directories
3129 mentioned in libthread-db-search-path. If you want to search those
3130 directories, they must be specified in libthread-db-search-path.
3131 The default value of libthread-db-search-path on GNU/Linux and Solaris
3132 systems is now "$sdir:$pdir".
3134 $pdir is not supported by gdbserver, it is currently ignored.
3135 $sdir is supported by gdbserver.
3137 * New configure option --with-iconv-bin.
3138 When using the internationalization support like the one in the GNU C
3139 library, GDB will invoke the "iconv" program to get a list of supported
3140 character sets. If this program lives in a non-standard location, one can
3141 use this option to specify where to find it.
3143 * When natively debugging programs on PowerPC BookE processors running
3144 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3145 watchpoints, which specify a mask in addition to an address to watch.
3146 The mask specifies that some bits of an address (the bits which are
3147 reset in the mask) should be ignored when matching the address accessed
3148 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3149 section in the user manual for more details.
3151 * The new option --once causes GDBserver to stop listening for connections once
3152 the first connection is made. The listening port used by GDBserver will
3153 become available after that.
3155 * New commands "info macros" and "alias" have been added.
3157 * New function parameters suffix @entry specifies value of function parameter
3158 at the time the function got called. Entry values are available only since
3164 "!" is now an alias of the "shell" command.
3165 Note that no space is needed between "!" and SHELL COMMAND.
3169 watch EXPRESSION mask MASK_VALUE
3170 The watch command now supports the mask argument which allows creation
3171 of masked watchpoints, if the current architecture supports this feature.
3173 info auto-load-scripts [REGEXP]
3174 This command was formerly named "maintenance print section-scripts".
3175 It is now generally useful and is no longer a maintenance-only command.
3177 info macro [-all] [--] MACRO
3178 The info macro command has new options `-all' and `--'. The first for
3179 printing all definitions of a macro. The second for explicitly specifying
3180 the end of arguments and the beginning of the macro name in case the macro
3181 name starts with a hyphen.
3183 collect[/s] EXPRESSIONS
3184 The tracepoint collect command now takes an optional modifier "/s"
3185 that directs it to dereference pointer-to-character types and
3186 collect the bytes of memory up to a zero byte. The behavior is
3187 similar to what you see when you use the regular print command on a
3188 string. An optional integer following the "/s" sets a bound on the
3189 number of bytes that will be collected.
3192 The trace start command now interprets any supplied arguments as a
3193 note to be recorded with the trace run, with an effect similar to
3194 setting the variable trace-notes.
3197 The trace stop command now interprets any arguments as a note to be
3198 mentioned along with the tstatus report that the trace was stopped
3199 with a command. The effect is similar to setting the variable
3202 * Tracepoints can now be enabled and disabled at any time after a trace
3203 experiment has been started using the standard "enable" and "disable"
3204 commands. It is now possible to start a trace experiment with no enabled
3205 tracepoints; GDB will display a warning, but will allow the experiment to
3206 begin, assuming that tracepoints will be enabled as needed while the trace
3209 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3210 locations with 4-byte instructions, when they were previously
3211 limited to locations with instructions of 5 bytes or longer.
3215 set debug dwarf2-read
3216 show debug dwarf2-read
3217 Turns on or off display of debugging messages related to reading
3218 DWARF debug info. The default is off.
3220 set debug symtab-create
3221 show debug symtab-create
3222 Turns on or off display of debugging messages related to symbol table
3223 creation. The default is off.
3226 show extended-prompt
3227 Set the GDB prompt, and allow escape sequences to be inserted to
3228 display miscellaneous information (see 'help set extended-prompt'
3229 for the list of sequences). This prompt (and any information
3230 accessed through the escape sequences) is updated every time the
3231 prompt is displayed.
3233 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3234 show print entry-values
3235 Set printing of frame argument values at function entry. In some cases
3236 GDB can determine the value of function argument which was passed by the
3237 function caller, even if the value was modified inside the called function.
3239 set debug entry-values
3240 show debug entry-values
3241 Control display of debugging info for determining frame argument values at
3242 function entry and virtual tail call frames.
3244 set basenames-may-differ
3245 show basenames-may-differ
3246 Set whether a source file may have multiple base names.
3247 (A "base name" is the name of a file with the directory part removed.
3248 Example: The base name of "/home/user/hello.c" is "hello.c".)
3249 If set, GDB will canonicalize file names (e.g., expand symlinks)
3250 before comparing them. Canonicalization is an expensive operation,
3251 but it allows the same file be known by more than one base name.
3252 If not set (the default), all source files are assumed to have just
3253 one base name, and gdb will do file name comparisons more efficiently.
3259 Set a user name and notes for the current and any future trace runs.
3260 This is useful for long-running and/or disconnected traces, to
3261 inform others (or yourself) as to who is running the trace, supply
3262 contact information, or otherwise explain what is going on.
3264 set trace-stop-notes
3265 show trace-stop-notes
3266 Set a note attached to the trace run, that is displayed when the
3267 trace has been stopped by a tstop command. This is useful for
3268 instance as an explanation, if you are stopping a trace run that was
3269 started by someone else.
3271 * New remote packets
3275 Dynamically enable a tracepoint in a started trace experiment.
3279 Dynamically disable a tracepoint in a started trace experiment.
3283 Set the user and notes of the trace run.
3287 Query the current status of a tracepoint.
3291 Query the minimum length of instruction at which a fast tracepoint may
3294 * Dcache size (number of lines) and line-size are now runtime-configurable
3295 via "set dcache line" and "set dcache line-size" commands.
3299 Texas Instruments TMS320C6x tic6x-*-*
3303 Renesas RL78 rl78-*-elf
3305 *** Changes in GDB 7.3.1
3307 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3309 *** Changes in GDB 7.3
3311 * GDB has a new command: "thread find [REGEXP]".
3312 It finds the thread id whose name, target id, or thread extra info
3313 matches the given regular expression.
3315 * The "catch syscall" command now works on mips*-linux* targets.
3317 * The -data-disassemble MI command now supports modes 2 and 3 for
3318 dumping the instruction opcodes.
3320 * New command line options
3322 -data-directory DIR Specify DIR as the "data-directory".
3323 This is mostly for testing purposes.
3325 * The "maint set python auto-load on|off" command has been renamed to
3326 "set auto-load-scripts on|off".
3328 * GDB has a new command: "set directories".
3329 It is like the "dir" command except that it replaces the
3330 source path list instead of augmenting it.
3332 * GDB now understands thread names.
3334 On GNU/Linux, "info threads" will display the thread name as set by
3335 prctl or pthread_setname_np.
3337 There is also a new command, "thread name", which can be used to
3338 assign a name internally for GDB to display.
3341 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3342 has been integrated into GDB.
3346 ** The function gdb.Write now accepts an optional keyword 'stream'.
3347 This keyword, when provided, will direct the output to either
3348 stdout, stderr, or GDB's logging output.
3350 ** Parameters can now be be sub-classed in Python, and in particular
3351 you may implement the get_set_doc and get_show_doc functions.
3352 This improves how Parameter set/show documentation is processed
3353 and allows for more dynamic content.
3355 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3356 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3357 have an is_valid method.
3359 ** Breakpoints can now be sub-classed in Python, and in particular
3360 you may implement a 'stop' function that is executed each time
3361 the inferior reaches that breakpoint.
3363 ** New function gdb.lookup_global_symbol looks up a global symbol.
3365 ** GDB values in Python are now callable if the value represents a
3366 function. For example, if 'some_value' represents a function that
3367 takes two integer parameters and returns a value, you can call
3368 that function like so:
3370 result = some_value (10,20)
3372 ** Module gdb.types has been added.
3373 It contains a collection of utilities for working with gdb.Types objects:
3374 get_basic_type, has_field, make_enum_dict.
3376 ** Module gdb.printing has been added.
3377 It contains utilities for writing and registering pretty-printers.
3378 New classes: PrettyPrinter, SubPrettyPrinter,
3379 RegexpCollectionPrettyPrinter.
3380 New function: register_pretty_printer.
3382 ** New commands "info pretty-printers", "enable pretty-printer" and
3383 "disable pretty-printer" have been added.
3385 ** gdb.parameter("directories") is now available.
3387 ** New function gdb.newest_frame returns the newest frame in the
3390 ** The gdb.InferiorThread class has a new "name" attribute. This
3391 holds the thread's name.
3393 ** Python Support for Inferior events.
3394 Python scripts can add observers to be notified of events
3395 occurring in the process being debugged.
3396 The following events are currently supported:
3397 - gdb.events.cont Continue event.
3398 - gdb.events.exited Inferior exited event.
3399 - gdb.events.stop Signal received, and Breakpoint hit events.
3403 ** GDB now puts template parameters in scope when debugging in an
3404 instantiation. For example, if you have:
3406 template<int X> int func (void) { return X; }
3408 then if you step into func<5>, "print X" will show "5". This
3409 feature requires proper debuginfo support from the compiler; it
3410 was added to GCC 4.5.
3412 ** The motion commands "next", "finish", "until", and "advance" now
3413 work better when exceptions are thrown. In particular, GDB will
3414 no longer lose control of the inferior; instead, the GDB will
3415 stop the inferior at the point at which the exception is caught.
3416 This functionality requires a change in the exception handling
3417 code that was introduced in GCC 4.5.
3419 * GDB now follows GCC's rules on accessing volatile objects when
3420 reading or writing target state during expression evaluation.
3421 One notable difference to prior behavior is that "print x = 0"
3422 no longer generates a read of x; the value of the assignment is
3423 now always taken directly from the value being assigned.
3425 * GDB now has some support for using labels in the program's source in
3426 linespecs. For instance, you can use "advance label" to continue
3427 execution to a label.
3429 * GDB now has support for reading and writing a new .gdb_index
3430 section. This section holds a fast index of DWARF debugging
3431 information and can be used to greatly speed up GDB startup and
3432 operation. See the documentation for `save gdb-index' for details.
3434 * The "watch" command now accepts an optional "-location" argument.
3435 When used, this causes GDB to watch the memory referred to by the
3436 expression. Such a watchpoint is never deleted due to it going out
3439 * GDB now supports thread debugging of core dumps on GNU/Linux.
3441 GDB now activates thread debugging using the libthread_db library
3442 when debugging GNU/Linux core dumps, similarly to when debugging
3443 live processes. As a result, when debugging a core dump file, GDB
3444 is now able to display pthread_t ids of threads. For example, "info
3445 threads" shows the same output as when debugging the process when it
3446 was live. In earlier releases, you'd see something like this:
3449 * 1 LWP 6780 main () at main.c:10
3451 While now you see this:
3454 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3456 It is also now possible to inspect TLS variables when debugging core
3459 When debugging a core dump generated on a machine other than the one
3460 used to run GDB, you may need to point GDB at the correct
3461 libthread_db library with the "set libthread-db-search-path"
3462 command. See the user manual for more details on this command.
3464 * When natively debugging programs on PowerPC BookE processors running
3465 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3466 which stop execution of the inferior whenever it executes an instruction
3467 at any address within the specified range. See the "PowerPC Embedded"
3468 section in the user manual for more details.
3470 * New features in the GDB remote stub, GDBserver
3472 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3473 and i686 LynxOS (version 5.x).
3475 ** GDBserver is now supported on Blackfin Linux.
3477 * New native configurations
3479 ia64 HP-UX ia64-*-hpux*
3483 Analog Devices, Inc. Blackfin Processor bfin-*
3485 * Ada task switching is now supported on sparc-elf targets when
3486 debugging a program using the Ravenscar Profile. For more information,
3487 see the "Tasking Support when using the Ravenscar Profile" section
3488 in the GDB user manual.
3490 * Guile support was removed.
3492 * New features in the GNU simulator
3494 ** The --map-info flag lists all known core mappings.
3496 ** CFI flashes may be simulated via the "cfi" device.
3498 *** Changes in GDB 7.2
3500 * Shared library support for remote targets by default
3502 When GDB is configured for a generic, non-OS specific target, like
3503 for example, --target=arm-eabi or one of the many *-*-elf targets,
3504 GDB now queries remote stubs for loaded shared libraries using the
3505 `qXfer:libraries:read' packet. Previously, shared library support
3506 was always disabled for such configurations.
3510 ** Argument Dependent Lookup (ADL)
3512 In C++ ADL lookup directs function search to the namespaces of its
3513 arguments even if the namespace has not been imported.
3523 Here the compiler will search for `foo' in the namespace of 'b'
3524 and find A::foo. GDB now supports this. This construct is commonly
3525 used in the Standard Template Library for operators.
3527 ** Improved User Defined Operator Support
3529 In addition to member operators, GDB now supports lookup of operators
3530 defined in a namespace and imported with a `using' directive, operators
3531 defined in the global scope, operators imported implicitly from an
3532 anonymous namespace, and the ADL operators mentioned in the previous
3534 GDB now also supports proper overload resolution for all the previously
3535 mentioned flavors of operators.
3537 ** static const class members
3539 Printing of static const class members that are initialized in the
3540 class definition has been fixed.
3542 * Windows Thread Information Block access.
3544 On Windows targets, GDB now supports displaying the Windows Thread
3545 Information Block (TIB) structure. This structure is visible either
3546 by using the new command `info w32 thread-information-block' or, by
3547 dereferencing the new convenience variable named `$_tlb', a
3548 thread-specific pointer to the TIB. This feature is also supported
3549 when remote debugging using GDBserver.
3551 * Static tracepoints
3553 Static tracepoints are calls in the user program into a tracing
3554 library. One such library is a port of the LTTng kernel tracer to
3555 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3556 When debugging with GDBserver, GDB now supports combining the GDB
3557 tracepoint machinery with such libraries. For example: the user can
3558 use GDB to probe a static tracepoint marker (a call from the user
3559 program into the tracing library) with the new "strace" command (see
3560 "New commands" below). This creates a "static tracepoint" in the
3561 breakpoint list, that can be manipulated with the same feature set
3562 as fast and regular tracepoints. E.g., collect registers, local and
3563 global variables, collect trace state variables, and define
3564 tracepoint conditions. In addition, the user can collect extra
3565 static tracepoint marker specific data, by collecting the new
3566 $_sdata internal variable. When analyzing the trace buffer, you can
3567 inspect $_sdata like any other variable available to GDB. For more
3568 information, see the "Tracepoints" chapter in GDB user manual. New
3569 remote packets have been defined to support static tracepoints, see
3570 the "New remote packets" section below.
3572 * Better reconstruction of tracepoints after disconnected tracing
3574 GDB will attempt to download the original source form of tracepoint
3575 definitions when starting a trace run, and then will upload these
3576 upon reconnection to the target, resulting in a more accurate
3577 reconstruction of the tracepoints that are in use on the target.
3581 You can now exercise direct control over the ways that GDB can
3582 affect your program. For instance, you can disallow the setting of
3583 breakpoints, so that the program can run continuously (assuming
3584 non-stop mode). In addition, the "observer" variable is available
3585 to switch all of the different controls; in observer mode, GDB
3586 cannot affect the target's behavior at all, which is useful for
3587 tasks like diagnosing live systems in the field.
3589 * The new convenience variable $_thread holds the number of the
3592 * New remote packets
3596 Return the address of the Windows Thread Information Block of a given thread.
3600 In response to several of the tracepoint packets, the target may now
3601 also respond with a number of intermediate `qRelocInsn' request
3602 packets before the final result packet, to have GDB handle
3603 relocating an instruction to execute at a different address. This
3604 is particularly useful for stubs that support fast tracepoints. GDB
3605 reports support for this feature in the qSupported packet.
3609 List static tracepoint markers in the target program.
3613 List static tracepoint markers at a given address in the target
3616 qXfer:statictrace:read
3618 Read the static trace data collected (by a `collect $_sdata'
3619 tracepoint action). The remote stub reports support for this packet
3620 to gdb's qSupported query.
3624 Send the current settings of GDB's permission flags.
3628 Send part of the source (textual) form of a tracepoint definition,
3629 which includes location, conditional, and action list.
3631 * The source command now accepts a -s option to force searching for the
3632 script in the source search path even if the script name specifies
3635 * New features in the GDB remote stub, GDBserver
3637 - GDBserver now support tracepoints (including fast tracepoints, and
3638 static tracepoints). The feature is currently supported by the
3639 i386-linux and amd64-linux builds. See the "Tracepoints support
3640 in gdbserver" section in the manual for more information.
3642 GDBserver JIT compiles the tracepoint's conditional agent
3643 expression bytecode into native code whenever possible for low
3644 overhead dynamic tracepoints conditionals. For such tracepoints,
3645 an expression that examines program state is evaluated when the
3646 tracepoint is reached, in order to determine whether to capture
3647 trace data. If the condition is simple and false, processing the
3648 tracepoint finishes very quickly and no data is gathered.
3650 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3651 for static tracepoints support.
3653 - GDBserver now supports x86_64 Windows 64-bit debugging.
3655 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3656 it understands register description.
3658 * The --batch flag now disables pagination and queries.
3660 * X86 general purpose registers
3662 GDB now supports reading/writing byte, word and double-word x86
3663 general purpose registers directly. This means you can use, say,
3664 $ah or $ax to refer, respectively, to the byte register AH and
3665 16-bit word register AX that are actually portions of the 32-bit
3666 register EAX or 64-bit register RAX.
3668 * The `commands' command now accepts a range of breakpoints to modify.
3669 A plain `commands' following a command that creates multiple
3670 breakpoints affects all the breakpoints set by that command. This
3671 applies to breakpoints set by `rbreak', and also applies when a
3672 single `break' command creates multiple breakpoints (e.g.,
3673 breakpoints on overloaded c++ functions).
3675 * The `rbreak' command now accepts a filename specification as part of
3676 its argument, limiting the functions selected by the regex to those
3677 in the specified file.
3679 * Support for remote debugging Windows and SymbianOS shared libraries
3680 from Unix hosts has been improved. Non Windows GDB builds now can
3681 understand target reported file names that follow MS-DOS based file
3682 system semantics, such as file names that include drive letters and
3683 use the backslash character as directory separator. This makes it
3684 possible to transparently use the "set sysroot" and "set
3685 solib-search-path" on Unix hosts to point as host copies of the
3686 target's shared libraries. See the new command "set
3687 target-file-system-kind" described below, and the "Commands to
3688 specify files" section in the user manual for more information.
3692 eval template, expressions...
3693 Convert the values of one or more expressions under the control
3694 of the string template to a command line, and call it.
3696 set target-file-system-kind unix|dos-based|auto
3697 show target-file-system-kind
3698 Set or show the assumed file system kind for target reported file
3701 save breakpoints <filename>
3702 Save all current breakpoint definitions to a file suitable for use
3703 in a later debugging session. To read the saved breakpoint
3704 definitions, use the `source' command.
3706 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3709 info static-tracepoint-markers
3710 Display information about static tracepoint markers in the target.
3712 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3713 Define a static tracepoint by probing a marker at the given
3714 function, line, address, or marker ID.
3718 Enable and disable observer mode.
3720 set may-write-registers on|off
3721 set may-write-memory on|off
3722 set may-insert-breakpoints on|off
3723 set may-insert-tracepoints on|off
3724 set may-insert-fast-tracepoints on|off
3725 set may-interrupt on|off
3726 Set individual permissions for GDB effects on the target. Note that
3727 some of these settings can have undesirable or surprising
3728 consequences, particularly when changed in the middle of a session.
3729 For instance, disabling the writing of memory can prevent
3730 breakpoints from being inserted, cause single-stepping to fail, or
3731 even crash your program, if you disable after breakpoints have been
3732 inserted. However, GDB should not crash.
3734 set record memory-query on|off
3735 show record memory-query
3736 Control whether to stop the inferior if memory changes caused
3737 by an instruction cannot be recorded.
3742 The disassemble command now supports "start,+length" form of two arguments.
3746 ** GDB now provides a new directory location, called the python directory,
3747 where Python scripts written for GDB can be installed. The location
3748 of that directory is <data-directory>/python, where <data-directory>
3749 is the GDB data directory. For more details, see section `Scripting
3750 GDB using Python' in the manual.
3752 ** The GDB Python API now has access to breakpoints, symbols, symbol
3753 tables, program spaces, inferiors, threads and frame's code blocks.
3754 Additionally, GDB Parameters can now be created from the API, and
3755 manipulated via set/show in the CLI.
3757 ** New functions gdb.target_charset, gdb.target_wide_charset,
3758 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3760 ** New exception gdb.GdbError.
3762 ** Pretty-printers are now also looked up in the current program space.
3764 ** Pretty-printers can now be individually enabled and disabled.
3766 ** GDB now looks for names of Python scripts to auto-load in a
3767 special section named `.debug_gdb_scripts', in addition to looking
3768 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3770 * Tracepoint actions were unified with breakpoint commands. In particular,
3771 there are no longer differences in "info break" output for breakpoints and
3772 tracepoints and the "commands" command can be used for both tracepoints and
3773 regular breakpoints.
3777 ARM Symbian arm*-*-symbianelf*
3779 * D language support.
3780 GDB now supports debugging programs written in the D programming
3783 * GDB now supports the extended ptrace interface for PowerPC which is
3784 available since Linux kernel version 2.6.34. This automatically enables
3785 any hardware breakpoints and additional hardware watchpoints available in
3786 the processor. The old ptrace interface exposes just one hardware
3787 watchpoint and no hardware breakpoints.
3789 * GDB is now able to use the Data Value Compare (DVC) register available on
3790 embedded PowerPC processors to implement in hardware simple watchpoint
3791 conditions of the form:
3793 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3795 This works in native GDB running on Linux kernels with the extended ptrace
3796 interface mentioned above.
3798 *** Changes in GDB 7.1
3802 ** Namespace Support
3804 GDB now supports importing of namespaces in C++. This enables the
3805 user to inspect variables from imported namespaces. Support for
3806 namepace aliasing has also been added. So, if a namespace is
3807 aliased in the current scope (e.g. namepace C=A; ) the user can
3808 print variables using the alias (e.g. (gdb) print C::x).
3812 All known bugs relating to the printing of virtual base class were
3813 fixed. It is now possible to call overloaded static methods using a
3818 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3819 and reinterpret_cast<> are now handled by the C++ expression parser.
3823 Xilinx MicroBlaze microblaze-*-*
3828 Xilinx MicroBlaze microblaze
3831 * Multi-program debugging.
3833 GDB now has support for multi-program (a.k.a. multi-executable or
3834 multi-exec) debugging. This allows for debugging multiple inferiors
3835 simultaneously each running a different program under the same GDB
3836 session. See "Debugging Multiple Inferiors and Programs" in the
3837 manual for more information. This implied some user visible changes
3838 in the multi-inferior support. For example, "info inferiors" now
3839 lists inferiors that are not running yet or that have exited
3840 already. See also "New commands" and "New options" below.
3842 * New tracing features
3844 GDB's tracepoint facility now includes several new features:
3846 ** Trace state variables
3848 GDB tracepoints now include support for trace state variables, which
3849 are variables managed by the target agent during a tracing
3850 experiment. They are useful for tracepoints that trigger each
3851 other, so for instance one tracepoint can count hits in a variable,
3852 and then a second tracepoint has a condition that is true when the
3853 count reaches a particular value. Trace state variables share the
3854 $-syntax of GDB convenience variables, and can appear in both
3855 tracepoint actions and condition expressions. Use the "tvariable"
3856 command to create, and "info tvariables" to view; see "Trace State
3857 Variables" in the manual for more detail.
3861 GDB now includes an option for defining fast tracepoints, which
3862 targets may implement more efficiently, such as by installing a jump
3863 into the target agent rather than a trap instruction. The resulting
3864 speedup can be by two orders of magnitude or more, although the
3865 tradeoff is that some program locations on some target architectures
3866 might not allow fast tracepoint installation, for instance if the
3867 instruction to be replaced is shorter than the jump. To request a
3868 fast tracepoint, use the "ftrace" command, with syntax identical to
3869 the regular trace command.
3871 ** Disconnected tracing
3873 It is now possible to detach GDB from the target while it is running
3874 a trace experiment, then reconnect later to see how the experiment
3875 is going. In addition, a new variable disconnected-tracing lets you
3876 tell the target agent whether to continue running a trace if the
3877 connection is lost unexpectedly.
3881 GDB now has the ability to save the trace buffer into a file, and
3882 then use that file as a target, similarly to you can do with
3883 corefiles. You can select trace frames, print data that was
3884 collected in them, and use tstatus to display the state of the
3885 tracing run at the moment that it was saved. To create a trace
3886 file, use "tsave <filename>", and to use it, do "target tfile
3889 ** Circular trace buffer
3891 You can ask the target agent to handle the trace buffer as a
3892 circular buffer, discarding the oldest trace frames to make room for
3893 newer ones, by setting circular-trace-buffer to on. This feature may
3894 not be available for all target agents.
3899 The disassemble command, when invoked with two arguments, now requires
3900 the arguments to be comma-separated.
3903 The info variables command now displays variable definitions. Files
3904 which only declare a variable are not shown.
3907 The source command is now capable of sourcing Python scripts.
3908 This feature is dependent on the debugger being build with Python
3911 Related to this enhancement is also the introduction of a new command
3912 "set script-extension" (see below).
3914 * New commands (for set/show, see "New options" below)
3916 record save [<FILENAME>]
3917 Save a file (in core file format) containing the process record
3918 execution log for replay debugging at a later time.
3920 record restore <FILENAME>
3921 Restore the process record execution log that was saved at an
3922 earlier time, for replay debugging.
3924 add-inferior [-copies <N>] [-exec <FILENAME>]
3927 clone-inferior [-copies <N>] [ID]
3928 Make a new inferior ready to execute the same program another
3929 inferior has loaded.
3934 maint info program-spaces
3935 List the program spaces loaded into GDB.
3937 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3938 show remote interrupt-sequence
3939 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3940 as the sequence to the remote target in order to interrupt the execution.
3941 Ctrl-C is a default. Some system prefers BREAK which is high level of
3942 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3943 Magic SysRq g. It is BREAK signal and character 'g'.
3945 set remote interrupt-on-connect [on | off]
3946 show remote interrupt-on-connect
3947 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3948 remote target when gdb connects to it. This is needed when you debug
3951 set remotebreak [on | off]
3953 Deprecated. Use "set/show remote interrupt-sequence" instead.
3955 tvariable $NAME [ = EXP ]
3956 Create or modify a trace state variable.
3959 List trace state variables and their values.
3961 delete tvariable $NAME ...
3962 Delete one or more trace state variables.
3965 Evaluate the given expressions without collecting anything into the
3966 trace buffer. (Valid in tracepoint actions only.)
3968 ftrace FN / FILE:LINE / *ADDR
3969 Define a fast tracepoint at the given function, line, or address.
3971 * New expression syntax
3973 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3974 GDB now parses 0b101010 identically with 42.
3978 set follow-exec-mode new|same
3979 show follow-exec-mode
3980 Control whether GDB reuses the same inferior across an exec call or
3981 creates a new one. This is useful to be able to restart the old
3982 executable after the inferior having done an exec call.
3984 set default-collect EXPR, ...
3985 show default-collect
3986 Define a list of expressions to be collected at each tracepoint.
3987 This is a useful way to ensure essential items are not overlooked,
3988 such as registers or a critical global variable.
3990 set disconnected-tracing
3991 show disconnected-tracing
3992 If set to 1, the target is instructed to continue tracing if it
3993 loses its connection to GDB. If 0, the target is to stop tracing
3996 set circular-trace-buffer
3997 show circular-trace-buffer
3998 If set to on, the target is instructed to use a circular trace buffer
3999 and discard the oldest trace frames instead of stopping the trace due
4000 to a full trace buffer. If set to off, the trace stops when the buffer
4001 fills up. Some targets may not support this.
4003 set script-extension off|soft|strict
4004 show script-extension
4005 If set to "off", the debugger does not perform any script language
4006 recognition, and all sourced files are assumed to be GDB scripts.
4007 If set to "soft" (the default), files are sourced according to
4008 filename extension, falling back to GDB scripts if the first
4010 If set to "strict", files are sourced according to filename extension.
4012 set ada trust-PAD-over-XVS on|off
4013 show ada trust-PAD-over-XVS
4014 If off, activate a workaround against a bug in the debugging information
4015 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4016 the GCC sources for more information about the GNAT encoding and
4017 PAD types in particular). It is always safe to set this option to
4018 off, but this introduces a slight performance penalty. The default
4021 * Python API Improvements
4023 ** GDB provides the new class gdb.LazyString. This is useful in
4024 some pretty-printing cases. The new method gdb.Value.lazy_string
4025 provides a simple way to create objects of this type.
4027 ** The fields returned by gdb.Type.fields now have an
4028 `is_base_class' attribute.
4030 ** The new method gdb.Type.range returns the range of an array type.
4032 ** The new method gdb.parse_and_eval can be used to parse and
4033 evaluate an expression.
4035 * New remote packets
4038 Define a trace state variable.
4041 Get the current value of a trace state variable.
4044 Set desired tracing behavior upon disconnection.
4047 Set the trace buffer to be linear or circular.
4050 Get data about the tracepoints currently in use.
4054 Process record now works correctly with hardware watchpoints.
4056 Multiple bug fixes have been made to the mips-irix port, making it
4057 much more reliable. In particular:
4058 - Debugging threaded applications is now possible again. Previously,
4059 GDB would hang while starting the program, or while waiting for
4060 the program to stop at a breakpoint.
4061 - Attaching to a running process no longer hangs.
4062 - An error occurring while loading a core file has been fixed.
4063 - Changing the value of the PC register now works again. This fixes
4064 problems observed when using the "jump" command, or when calling
4065 a function from GDB, or even when assigning a new value to $pc.
4066 - With the "finish" and "return" commands, the return value for functions
4067 returning a small array is now correctly printed.
4068 - It is now possible to break on shared library code which gets executed
4069 during a shared library init phase (code executed while executing
4070 their .init section). Previously, the breakpoint would have no effect.
4071 - GDB is now able to backtrace through the signal handler for
4072 non-threaded programs.
4074 PIE (Position Independent Executable) programs debugging is now supported.
4075 This includes debugging execution of PIC (Position Independent Code) shared
4076 libraries although for that, it should be possible to run such libraries as an
4079 *** Changes in GDB 7.0
4081 * GDB now has an interface for JIT compilation. Applications that
4082 dynamically generate code can create symbol files in memory and register
4083 them with GDB. For users, the feature should work transparently, and
4084 for JIT developers, the interface is documented in the GDB manual in the
4085 "JIT Compilation Interface" chapter.
4087 * Tracepoints may now be conditional. The syntax is as for
4088 breakpoints; either an "if" clause appended to the "trace" command,
4089 or the "condition" command is available. GDB sends the condition to
4090 the target for evaluation using the same bytecode format as is used
4091 for tracepoint actions.
4093 * The disassemble command now supports: an optional /r modifier, print the
4094 raw instructions in hex as well as in symbolic form, and an optional /m
4095 modifier to print mixed source+assembly.
4097 * Process record and replay
4099 In a architecture environment that supports ``process record and
4100 replay'', ``process record and replay'' target can record a log of
4101 the process execution, and replay it with both forward and reverse
4104 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4105 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4106 set execution-direction {forward|reverse}, for targets that support
4109 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4110 feature is available with a native GDB running on kernel version
4113 * GDB now has support for multi-byte and wide character sets on the
4114 target. Strings whose character type is wchar_t, char16_t, or
4115 char32_t are now correctly printed. GDB supports wide- and unicode-
4116 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4117 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4118 `printf'. This feature requires iconv to work properly; if your
4119 system does not have a working iconv, GDB can use GNU libiconv. See
4120 the installation instructions for more information.
4122 * GDB now supports automatic retrieval of shared library files from
4123 remote targets. To use this feature, specify a system root that begins
4124 with the `remote:' prefix, either via the `set sysroot' command or via
4125 the `--with-sysroot' configure-time option.
4127 * "info sharedlibrary" now takes an optional regex of libraries to show,
4128 and it now reports if a shared library has no debugging information.
4130 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4131 now complete on file names.
4133 * When completing in expressions, gdb will attempt to limit
4134 completions to allowable structure or union fields, where appropriate.
4135 For instance, consider:
4137 # struct example { int f1; double f2; };
4138 # struct example variable;
4141 If the user types TAB at the end of this command line, the available
4142 completions will be "f1" and "f2".
4144 * Inlined functions are now supported. They show up in backtraces, and
4145 the "step", "next", and "finish" commands handle them automatically.
4147 * GDB now supports the token-splicing (##) and stringification (#)
4148 operators when expanding macros. It also supports variable-arity
4151 * GDB now supports inspecting extra signal information, exported by
4152 the new $_siginfo convenience variable. The feature is currently
4153 implemented on linux ARM, i386 and amd64.
4155 * GDB can now display the VFP floating point registers and NEON vector
4156 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4157 can provide these registers (requires Linux 2.6.30 or later). Remote
4158 and simulator targets may also provide them.
4160 * New remote packets
4163 Search memory for a sequence of bytes.
4166 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4167 operation over reliable transport links. Use of this packet is
4168 controlled by the `set remote noack-packet' command.
4171 Kill the process with the specified process ID. Use this in preference
4172 to `k' when multiprocess protocol extensions are supported.
4175 Obtains additional operating system information
4179 Read or write additional signal information.
4181 * Removed remote protocol undocumented extension
4183 An undocumented extension to the remote protocol's `S' stop reply
4184 packet that permited the stub to pass a process id was removed.
4185 Remote servers should use the `T' stop reply packet instead.
4187 * GDB now supports multiple function calling conventions according to the
4188 DWARF-2 DW_AT_calling_convention function attribute.
4190 * The SH target utilizes the aforementioned change to distinguish between gcc
4191 and Renesas calling convention. It also adds the new CLI commands
4192 `set/show sh calling-convention'.
4194 * GDB can now read compressed debug sections, as produced by GNU gold
4195 with the --compress-debug-sections=zlib flag.
4197 * 64-bit core files are now supported on AIX.
4199 * Thread switching is now supported on Tru64.
4201 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4202 which will be allocated using malloc later in program execution.
4204 * The qXfer:libraries:read remote procotol packet now allows passing a
4205 list of section offsets.
4207 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4208 conditions handling signals delivered during attach or thread creation
4209 have also been fixed.
4211 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4212 From the user's standpoint, all unqualified instances of True and False
4213 are treated as the standard definitions, regardless of context.
4215 * GDB now parses C++ symbol and type names more flexibly. For
4218 template<typename T> class C { };
4221 GDB will now correctly handle all of:
4223 ptype C<char const *>
4224 ptype C<char const*>
4225 ptype C<const char *>
4226 ptype C<const char*>
4228 * New features in the GDB remote stub, gdbserver
4230 - The "--wrapper" command-line argument tells gdbserver to use a
4231 wrapper program to launch programs for debugging.
4233 - On PowerPC and S/390 targets, it is now possible to use a single
4234 gdbserver executable to debug both 32-bit and 64-bit programs.
4235 (This requires gdbserver itself to be built as a 64-bit executable.)
4237 - gdbserver uses the new noack protocol mode for TCP connections to
4238 reduce communications latency, if also supported and enabled in GDB.
4240 - Support for the sparc64-linux-gnu target is now included in
4243 - The amd64-linux build of gdbserver now supports debugging both
4244 32-bit and 64-bit programs.
4246 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4247 now support hardware watchpoints, and will use them automatically
4252 GDB now has support for scripting using Python. Whether this is
4253 available is determined at configure time.
4255 New GDB commands can now be written in Python.
4257 * Ada tasking support
4259 Ada tasks can now be inspected in GDB. The following commands have
4263 Print the list of Ada tasks.
4265 Print detailed information about task number N.
4267 Print the task number of the current task.
4269 Switch the context of debugging to task number N.
4271 * Support for user-defined prefixed commands. The "define" command can
4272 add new commands to existing prefixes, e.g. "target".
4274 * Multi-inferior, multi-process debugging.
4276 GDB now has generalized support for multi-inferior debugging. See
4277 "Debugging Multiple Inferiors" in the manual for more information.
4278 Although availability still depends on target support, the command
4279 set is more uniform now. The GNU/Linux specific multi-forks support
4280 has been migrated to this new framework. This implied some user
4281 visible changes; see "New commands" and also "Removed commands"
4284 * Target descriptions can now describe the target OS ABI. See the
4285 "Target Description Format" section in the user manual for more
4288 * Target descriptions can now describe "compatible" architectures
4289 to indicate that the target can execute applications for a different
4290 architecture in addition to those for the main target architecture.
4291 See the "Target Description Format" section in the user manual for
4294 * Multi-architecture debugging.
4296 GDB now includes general supports for debugging applications on
4297 hybrid systems that use more than one single processor architecture
4298 at the same time. Each such hybrid architecture still requires
4299 specific support to be added. The only hybrid architecture supported
4300 in this version of GDB is the Cell Broadband Engine.
4302 * GDB now supports integrated debugging of Cell/B.E. applications that
4303 use both the PPU and SPU architectures. To enable support for hybrid
4304 Cell/B.E. debugging, you need to configure GDB to support both the
4305 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4306 --enable-targets configure option.
4308 * Non-stop mode debugging.
4310 For some targets, GDB now supports an optional mode of operation in
4311 which you can examine stopped threads while other threads continue
4312 to execute freely. This is referred to as non-stop mode, with the
4313 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4314 section in the user manual for more information.
4316 To be able to support remote non-stop debugging, a remote stub needs
4317 to implement the non-stop mode remote protocol extensions, as
4318 described in the "Remote Non-Stop" section of the user manual. The
4319 GDB remote stub, gdbserver, has been adjusted to support these
4320 extensions on linux targets.
4322 * New commands (for set/show, see "New options" below)
4324 catch syscall [NAME(S) | NUMBER(S)]
4325 Catch system calls. Arguments, which should be names of system
4326 calls or their numbers, mean catch only those syscalls. Without
4327 arguments, every syscall will be caught. When the inferior issues
4328 any of the specified syscalls, GDB will stop and announce the system
4329 call, both when it is called and when its call returns. This
4330 feature is currently available with a native GDB running on the
4331 Linux Kernel, under the following architectures: x86, x86_64,
4332 PowerPC and PowerPC64.
4334 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4336 Search memory for a sequence of bytes.
4338 maint set python print-stack
4339 maint show python print-stack
4340 Show a stack trace when an error is encountered in a Python script.
4343 Invoke CODE by passing it to the Python interpreter.
4348 These allow macros to be defined, undefined, and listed
4352 Show operating system information about processes.
4355 List the inferiors currently under GDB's control.
4358 Switch focus to inferior number NUM.
4361 Detach from inferior number NUM.
4364 Kill inferior number NUM.
4368 set spu stop-on-load
4369 show spu stop-on-load
4370 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4372 set spu auto-flush-cache
4373 show spu auto-flush-cache
4374 Control whether to automatically flush the software-managed cache
4375 during Cell/B.E. debugging.
4377 set sh calling-convention
4378 show sh calling-convention
4379 Control the calling convention used when calling SH target functions.
4382 show debug timestamp
4383 Control display of timestamps with GDB debugging output.
4385 set disassemble-next-line
4386 show disassemble-next-line
4387 Control display of disassembled source lines or instructions when
4390 set remote noack-packet
4391 show remote noack-packet
4392 Set/show the use of remote protocol QStartNoAckMode packet. See above
4393 under "New remote packets."
4395 set remote query-attached-packet
4396 show remote query-attached-packet
4397 Control use of remote protocol `qAttached' (query-attached) packet.
4399 set remote read-siginfo-object
4400 show remote read-siginfo-object
4401 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4404 set remote write-siginfo-object
4405 show remote write-siginfo-object
4406 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4409 set remote reverse-continue
4410 show remote reverse-continue
4411 Control use of remote protocol 'bc' (reverse-continue) packet.
4413 set remote reverse-step
4414 show remote reverse-step
4415 Control use of remote protocol 'bs' (reverse-step) packet.
4417 set displaced-stepping
4418 show displaced-stepping
4419 Control displaced stepping mode. Displaced stepping is a way to
4420 single-step over breakpoints without removing them from the debuggee.
4421 Also known as "out-of-line single-stepping".
4424 show debug displaced
4425 Control display of debugging info for displaced stepping.
4427 maint set internal-error
4428 maint show internal-error
4429 Control what GDB does when an internal error is detected.
4431 maint set internal-warning
4432 maint show internal-warning
4433 Control what GDB does when an internal warning is detected.
4438 Use a wrapper program to launch programs for debugging.
4440 set multiple-symbols (all|ask|cancel)
4441 show multiple-symbols
4442 The value of this variable can be changed to adjust the debugger behavior
4443 when an expression or a breakpoint location contains an ambiguous symbol
4444 name (an overloaded function name, for instance).
4446 set breakpoint always-inserted
4447 show breakpoint always-inserted
4448 Keep breakpoints always inserted in the target, as opposed to inserting
4449 them when resuming the target, and removing them when the target stops.
4450 This option can improve debugger performance on slow remote targets.
4452 set arm fallback-mode (arm|thumb|auto)
4453 show arm fallback-mode
4454 set arm force-mode (arm|thumb|auto)
4456 These commands control how ARM GDB determines whether instructions
4457 are ARM or Thumb. The default for both settings is auto, which uses
4458 the current CPSR value for instructions without symbols; previous
4459 versions of GDB behaved as if "set arm fallback-mode arm".
4461 set disable-randomization
4462 show disable-randomization
4463 Standalone programs run with the virtual address space randomization enabled
4464 by default on some platforms. This option keeps the addresses stable across
4465 multiple debugging sessions.
4469 Control whether other threads are stopped or not when some thread hits
4474 Requests that asynchronous execution is enabled in the target, if available.
4475 In this case, it's possible to resume target in the background, and interact
4476 with GDB while the target is running. "show target-async" displays the
4477 current state of asynchronous execution of the target.
4479 set target-wide-charset
4480 show target-wide-charset
4481 The target-wide-charset is the name of the character set that GDB
4482 uses when printing characters whose type is wchar_t.
4484 set tcp auto-retry (on|off)
4486 set tcp connect-timeout
4487 show tcp connect-timeout
4488 These commands allow GDB to retry failed TCP connections to a remote stub
4489 with a specified timeout period; this is useful if the stub is launched
4490 in parallel with GDB but may not be ready to accept connections immediately.
4492 set libthread-db-search-path
4493 show libthread-db-search-path
4494 Control list of directories which GDB will search for appropriate
4497 set schedule-multiple (on|off)
4498 show schedule-multiple
4499 Allow GDB to resume all threads of all processes or only threads of
4500 the current process.
4504 Use more aggressive caching for accesses to the stack. This improves
4505 performance of remote debugging (particularly backtraces) without
4506 affecting correctness.
4508 set interactive-mode (on|off|auto)
4509 show interactive-mode
4510 Control whether GDB runs in interactive mode (on) or not (off).
4511 When in interactive mode, GDB waits for the user to answer all
4512 queries. Otherwise, GDB does not wait and assumes the default
4513 answer. When set to auto (the default), GDB determines which
4514 mode to use based on the stdin settings.
4519 For program forks, this is replaced by the new more generic `info
4520 inferiors' command. To list checkpoints, you can still use the
4521 `info checkpoints' command, which was an alias for the `info forks'
4525 Replaced by the new `inferior' command. To switch between
4526 checkpoints, you can still use the `restart' command, which was an
4527 alias for the `fork' command.
4530 This is removed, since some targets don't have a notion of
4531 processes. To switch between processes, you can still use the
4532 `inferior' command using GDB's own inferior number.
4535 For program forks, this is replaced by the new more generic `kill
4536 inferior' command. To delete a checkpoint, you can still use the
4537 `delete checkpoint' command, which was an alias for the `delete
4541 For program forks, this is replaced by the new more generic `detach
4542 inferior' command. To detach a checkpoint, you can still use the
4543 `detach checkpoint' command, which was an alias for the `detach
4546 * New native configurations
4548 x86/x86_64 Darwin i[34567]86-*-darwin*
4550 x86_64 MinGW x86_64-*-mingw*
4554 Lattice Mico32 lm32-*
4555 x86 DICOS i[34567]86-*-dicos*
4556 x86_64 DICOS x86_64-*-dicos*
4559 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4560 (mingw32ce) debugging.
4566 These commands were actually not implemented on any target.
4568 *** Changes in GDB 6.8
4570 * New native configurations
4572 NetBSD/hppa hppa*-*netbsd*
4573 Xtensa GNU/Linux xtensa*-*-linux*
4577 NetBSD/hppa hppa*-*-netbsd*
4578 Xtensa GNU/Lunux xtensa*-*-linux*
4580 * Change in command line behavior -- corefiles vs. process ids.
4582 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4583 attaching to process NUMBER fails, GDB no longer attempts to open a
4584 core file named NUMBER. Attaching to a program using the -c option
4585 is no longer supported. Instead, use the '-p' or '--pid' options.
4587 * GDB can now be built as a native debugger for debugging Windows x86
4588 (mingw32) Portable Executable (PE) programs.
4590 * Pending breakpoints no longer change their number when their address
4593 * GDB now supports breakpoints with multiple locations,
4594 including breakpoints on C++ constructors, inside C++ templates,
4595 and in inlined functions.
4597 * GDB's ability to debug optimized code has been improved. GDB more
4598 accurately identifies function bodies and lexical blocks that occupy
4599 more than one contiguous range of addresses.
4601 * Target descriptions can now describe registers for PowerPC.
4603 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4604 registers on PowerPC targets.
4606 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4607 targets even when the libthread_db library is not available.
4609 * The GDB remote stub, gdbserver, now supports the new file transfer
4610 commands (remote put, remote get, and remote delete).
4612 * The GDB remote stub, gdbserver, now supports run and attach in
4613 extended-remote mode.
4615 * hppa*64*-*-hpux11* target broken
4616 The debugger is unable to start a program and fails with the following
4617 error: "Error trying to get information about dynamic linker".
4618 The gdb-6.7 release is also affected.
4620 * GDB now supports the --enable-targets= configure option to allow
4621 building a single GDB executable that supports multiple remote
4622 target architectures.
4624 * GDB now supports debugging C and C++ programs which use the
4625 Decimal Floating Point extension. In addition, the PowerPC target
4626 now has a set of pseudo-registers to inspect decimal float values
4627 stored in two consecutive float registers.
4629 * The -break-insert MI command can optionally create pending
4632 * Improved support for debugging Ada
4633 Many improvements to the Ada language support have been made. These
4635 - Better support for Ada2005 interface types
4636 - Improved handling of arrays and slices in general
4637 - Better support for Taft-amendment types
4638 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4640 - Improved command completion in Ada
4643 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4648 set print frame-arguments (all|scalars|none)
4649 show print frame-arguments
4650 The value of this variable can be changed to control which argument
4651 values should be printed by the debugger when displaying a frame.
4656 Transfer files to and from a remote target, and delete remote files.
4663 Transfer files to and from a remote target, and delete remote files.
4665 * New remote packets
4672 Open, close, read, write, and delete files on the remote system.
4675 Attach to an existing process on the remote system, in extended-remote
4679 Run a new process on the remote system, in extended-remote mode.
4681 *** Changes in GDB 6.7
4683 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4684 bfd, libiberty and opcodes, as revealed by static analysis donated by
4685 Coverity, Inc. (http://scan.coverity.com).
4687 * When looking up multiply-defined global symbols, GDB will now prefer the
4688 symbol definition in the current shared library if it was built using the
4689 -Bsymbolic linker option.
4691 * When the Text User Interface (TUI) is not configured, GDB will now
4692 recognize the -tui command-line option and print a message that the TUI
4695 * The GDB remote stub, gdbserver, now has lower overhead for high
4696 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4698 * GDB for MIPS targets now autodetects whether a remote target provides
4699 32-bit or 64-bit register values.
4701 * Support for C++ member pointers has been improved.
4703 * GDB now understands XML target descriptions, which specify the
4704 target's overall architecture. GDB can read a description from
4705 a local file or over the remote serial protocol.
4707 * Vectors of single-byte data use a new integer type which is not
4708 automatically displayed as character or string data.
4710 * The /s format now works with the print command. It displays
4711 arrays of single-byte integers and pointers to single-byte integers
4714 * Target descriptions can now describe target-specific registers,
4715 for architectures which have implemented the support (currently
4716 only ARM, M68K, and MIPS).
4718 * GDB and the GDB remote stub, gdbserver, now support the XScale
4721 * The GDB remote stub, gdbserver, has been updated to support
4722 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4723 has been rewritten to use the standard GDB remote protocol.
4725 * GDB can now step into C++ functions which are called through thunks.
4727 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4729 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4730 layout. It also supports a TextSeg= and DataSeg= response when only
4731 segment base addresses (rather than offsets) are available.
4733 * The /i format now outputs any trailing branch delay slot instructions
4734 immediately following the last instruction within the count specified.
4736 * The GDB remote protocol "T" stop reply packet now supports a
4737 "library" response. Combined with the new "qXfer:libraries:read"
4738 packet, this response allows GDB to debug shared libraries on targets
4739 where the operating system manages the list of loaded libraries (e.g.
4740 Windows and SymbianOS).
4742 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4743 (DLLs) on Windows and Windows CE targets.
4745 * GDB now supports a faster verification that a .debug file matches its binary
4746 according to its build-id signature, if the signature is present.
4752 Enable or disable hardware flow control (RTS/CTS) on the serial port
4753 when debugging using remote targets.
4755 set mem inaccessible-by-default
4756 show mem inaccessible-by-default
4757 If the target supplies a memory map, for instance via the remote
4758 protocol's "qXfer:memory-map:read" packet, setting this variable
4759 prevents GDB from accessing memory outside the memory map. This
4760 is useful for targets with memory mapped registers or which react
4761 badly to accesses of unmapped address space.
4763 set breakpoint auto-hw
4764 show breakpoint auto-hw
4765 If the target supplies a memory map, for instance via the remote
4766 protocol's "qXfer:memory-map:read" packet, setting this variable
4767 lets GDB use hardware breakpoints automatically for memory regions
4768 where it can not use software breakpoints. This covers both the
4769 "break" command and internal breakpoints used for other commands
4770 including "next" and "finish".
4773 catch exception unhandled
4774 Stop the program execution when Ada exceptions are raised.
4777 Stop the program execution when an Ada assertion failed.
4781 Set an alternate system root for target files. This is a more
4782 general version of "set solib-absolute-prefix", which is now
4783 an alias to "set sysroot".
4786 Provide extended SPU facility status information. This set of
4787 commands is available only when debugging the Cell/B.E. SPU
4790 * New native configurations
4792 OpenBSD/sh sh*-*openbsd*
4795 unset tdesc filename
4797 Use the specified local file as an XML target description, and do
4798 not query the target for its built-in description.
4802 OpenBSD/sh sh*-*-openbsd*
4803 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4804 Toshiba Media Processor mep-elf
4806 * New remote packets
4809 Ignore the specified signals; pass them directly to the debugged program
4810 without stopping other threads or reporting them to GDB.
4812 qXfer:features:read:
4813 Read an XML target description from the target, which describes its
4818 Read or write contents of an spufs file on the target system. These
4819 packets are available only on the Cell/B.E. SPU architecture.
4821 qXfer:libraries:read:
4822 Report the loaded shared libraries. Combined with new "T" packet
4823 response, this packet allows GDB to debug shared libraries on
4824 targets where the operating system manages the list of loaded
4825 libraries (e.g. Windows and SymbianOS).
4829 Support for these obsolete configurations has been removed.
4837 i[34567]86-*-lynxos*
4838 i[34567]86-*-netware*
4839 i[34567]86-*-sco3.2v5*
4840 i[34567]86-*-sco3.2v4*
4842 i[34567]86-*-sysv4.2*
4845 i[34567]86-*-unixware2*
4846 i[34567]86-*-unixware*
4855 * Other removed features
4862 Various m68k-only ROM monitors.
4869 Various Renesas ROM monitors and debugging interfaces for SH and
4874 Support for a Macraigor serial interface to on-chip debugging.
4875 GDB does not directly support the newer parallel or USB
4880 A debug information format. The predecessor to DWARF 2 and
4881 DWARF 3, which are still supported.
4883 Support for the HP aCC compiler on HP-UX/PA-RISC
4885 SOM-encapsulated symbolic debugging information, automatic
4886 invocation of pxdb, and the aCC custom C++ ABI. This does not
4887 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4888 with aCC can still be debugged on an assembly level.
4890 MIPS ".pdr" sections
4892 A MIPS-specific format used to describe stack frame layout
4893 in debugging information.
4897 GDB could work with an older version of Guile to debug
4898 the interpreter and Scheme programs running in it.
4900 set mips stack-arg-size
4901 set mips saved-gpreg-size
4903 Use "set mips abi" to control parameter passing for MIPS.
4905 *** Changes in GDB 6.6
4910 Cell Broadband Engine SPU spu-elf
4912 * GDB can now be configured as a cross-debugger targeting native Windows
4913 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4914 running on a Windows system over TCP/IP to debug Windows programs.
4916 * The GDB remote stub, gdbserver, has been updated to support Windows and
4917 Cygwin debugging. Both single-threaded and multi-threaded programs are
4920 * The "set trust-readonly-sections" command works again. This command was
4921 broken in GDB 6.3, 6.4, and 6.5.
4923 * The "load" command now supports writing to flash memory, if the remote
4924 stub provides the required support.
4926 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4927 longer requires symbolic debug information (e.g. DWARF-2).
4932 unset substitute-path
4933 show substitute-path
4934 Manage a list of substitution rules that GDB uses to rewrite the name
4935 of the directories where the sources are located. This can be useful
4936 for instance when the sources were moved to a different location
4937 between compilation and debugging.
4941 Print each CLI command as it is executed. Each command is prefixed with
4942 a number of `+' symbols representing the nesting depth.
4943 The source command now has a `-v' option to enable the same feature.
4947 The ARM Demon monitor support (RDP protocol, "target rdp").
4949 Kernel Object Display, an embedded debugging feature which only worked with
4950 an obsolete version of Cisco IOS.
4952 The 'set download-write-size' and 'show download-write-size' commands.
4954 * New remote packets
4957 Tell a stub about GDB client features, and request remote target features.
4958 The first feature implemented is PacketSize, which allows the target to
4959 specify the size of packets it can handle - to minimize the number of
4960 packets required and improve performance when connected to a remote
4964 Fetch an OS auxilliary vector from the remote stub. This packet is a
4965 more efficient replacement for qPart:auxv:read.
4967 qXfer:memory-map:read:
4968 Fetch a memory map from the remote stub, including information about
4969 RAM, ROM, and flash memory devices.
4974 Erase and program a flash memory device.
4976 * Removed remote packets
4979 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4980 used it, and only gdbserver implemented it.
4982 *** Changes in GDB 6.5
4986 Renesas M32C/M16C m32c-elf
4988 Morpho Technologies ms1 ms1-elf
4992 init-if-undefined Initialize a convenience variable, but
4993 only if it doesn't already have a value.
4995 The following commands are presently only implemented for native GNU/Linux:
4997 checkpoint Save a snapshot of the program state.
4999 restart <n> Return the program state to a
5000 previously saved state.
5002 info checkpoints List currently saved checkpoints.
5004 delete-checkpoint <n> Delete a previously saved checkpoint.
5006 set|show detach-on-fork Tell gdb whether to detach from a newly
5007 forked process, or to keep debugging it.
5009 info forks List forks of the user program that
5010 are available to be debugged.
5012 fork <n> Switch to debugging one of several
5013 forks of the user program that are
5014 available to be debugged.
5016 delete-fork <n> Delete a fork from the list of forks
5017 that are available to be debugged (and
5018 kill the forked process).
5020 detach-fork <n> Delete a fork from the list of forks
5021 that are available to be debugged (and
5022 allow the process to continue).
5026 Morpho Technologies ms2 ms1-elf
5028 * Improved Windows host support
5030 GDB now builds as a cross debugger hosted on i686-mingw32, including
5031 native console support, and remote communications using either
5032 network sockets or serial ports.
5034 * Improved Modula-2 language support
5036 GDB can now print most types in the Modula-2 syntax. This includes:
5037 basic types, set types, record types, enumerated types, range types,
5038 pointer types and ARRAY types. Procedure var parameters are correctly
5039 printed and hexadecimal addresses and character constants are also
5040 written in the Modula-2 syntax. Best results can be obtained by using
5041 GNU Modula-2 together with the -gdwarf-2 command line option.
5045 The ARM rdi-share module.
5047 The Netware NLM debug server.
5049 *** Changes in GDB 6.4
5051 * New native configurations
5053 OpenBSD/arm arm*-*-openbsd*
5054 OpenBSD/mips64 mips64-*-openbsd*
5058 Morpho Technologies ms1 ms1-elf
5060 * New command line options
5062 --batch-silent As for --batch, but totally silent.
5063 --return-child-result The debugger will exist with the same value
5064 the child (debugged) program exited with.
5065 --eval-command COMMAND, -ex COMMAND
5066 Execute a single GDB CLI command. This may be
5067 specified multiple times and in conjunction
5068 with the --command (-x) option.
5070 * Deprecated commands removed
5072 The following commands, that were deprecated in 2000, have been
5076 set|show arm disassembly-flavor set|show arm disassembler
5077 othernames set arm disassembler
5078 set|show remotedebug set|show debug remote
5079 set|show archdebug set|show debug arch
5080 set|show eventdebug set|show debug event
5083 * New BSD user-level threads support
5085 It is now possible to debug programs using the user-level threads
5086 library on OpenBSD and FreeBSD. Currently supported (target)
5089 FreeBSD/amd64 x86_64-*-freebsd*
5090 FreeBSD/i386 i386-*-freebsd*
5091 OpenBSD/i386 i386-*-openbsd*
5093 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5094 are not yet supported.
5096 * New support for Matsushita MN10300 w/sim added
5097 (Work in progress). mn10300-elf.
5099 * REMOVED configurations and files
5101 VxWorks and the XDR protocol *-*-vxworks
5102 Motorola MCORE mcore-*-*
5103 National Semiconductor NS32000 ns32k-*-*
5105 * New "set print array-indexes" command
5107 After turning this setting "on", GDB prints the index of each element
5108 when displaying arrays. The default is "off" to preserve the previous
5111 * VAX floating point support
5113 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5115 * User-defined command support
5117 In addition to using $arg0..$arg9 for argument passing, it is now possible
5118 to use $argc to determine now many arguments have been passed. See the
5119 section on user-defined commands in the user manual for more information.
5121 *** Changes in GDB 6.3:
5123 * New command line option
5125 GDB now accepts -l followed by a number to set the timeout for remote
5128 * GDB works with GCC -feliminate-dwarf2-dups
5130 GDB now supports a more compact representation of DWARF-2 debug
5131 information using DW_FORM_ref_addr references. These are produced
5132 by GCC with the option -feliminate-dwarf2-dups and also by some
5133 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5134 to use -feliminate-dwarf2-dups.
5136 * Internationalization
5138 When supported by the host system, GDB will be built with
5139 internationalization (libintl). The task of marking up the sources is
5140 continued, we're looking forward to our first translation.
5144 Initial support for debugging programs compiled with the GNAT
5145 implementation of the Ada programming language has been integrated
5146 into GDB. In this release, support is limited to expression evaluation.
5148 * New native configurations
5150 GNU/Linux/m32r m32r-*-linux-gnu
5154 GDB's remote protocol now includes support for the 'p' packet. This
5155 packet is used to fetch individual registers from a remote inferior.
5157 * END-OF-LIFE registers[] compatibility module
5159 GDB's internal register infrastructure has been completely rewritten.
5160 The new infrastructure making possible the implementation of key new
5161 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5164 GDB 6.3 will be the last release to include the the registers[]
5165 compatibility module that allowed out-of-date configurations to
5166 continue to work. This change directly impacts the following
5176 powerpc bdm protocol
5178 Unless there is activity to revive these configurations, they will be
5179 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5181 * OBSOLETE configurations and files
5183 Configurations that have been declared obsolete in this release have
5184 been commented out. Unless there is activity to revive these
5185 configurations, the next release of GDB will have their sources
5186 permanently REMOVED.
5195 *** Changes in GDB 6.2.1:
5197 * MIPS `break main; run' gave an heuristic-fence-post warning
5199 When attempting to run even a simple program, a warning about
5200 heuristic-fence-post being hit would be reported. This problem has
5203 * MIPS IRIX 'long double' crashed GDB
5205 When examining a long double variable, GDB would get a segmentation
5206 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5207 IRIX long double values).
5211 A bug in the VAX stack code was causing problems with the "next"
5212 command. This problem has been fixed.
5214 *** Changes in GDB 6.2:
5216 * Fix for ``many threads''
5218 On GNU/Linux systems that use the NPTL threads library, a program
5219 rapidly creating and deleting threads would confuse GDB leading to the
5222 ptrace: No such process.
5223 thread_db_get_info: cannot get thread info: generic error
5225 This problem has been fixed.
5227 * "-async" and "-noasync" options removed.
5229 Support for the broken "-noasync" option has been removed (it caused
5232 * New ``start'' command.
5234 This command runs the program until the begining of the main procedure.
5236 * New BSD Kernel Data Access Library (libkvm) interface
5238 Using ``target kvm'' it is now possible to debug kernel core dumps and
5239 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5240 platforms. Currently supported (native-only) configurations are:
5242 FreeBSD/amd64 x86_64-*-freebsd*
5243 FreeBSD/i386 i?86-*-freebsd*
5244 NetBSD/i386 i?86-*-netbsd*
5245 NetBSD/m68k m68*-*-netbsd*
5246 NetBSD/sparc sparc-*-netbsd*
5247 OpenBSD/amd64 x86_64-*-openbsd*
5248 OpenBSD/i386 i?86-*-openbsd*
5249 OpenBSD/m68k m68*-openbsd*
5250 OpenBSD/sparc sparc-*-openbsd*
5252 * Signal trampoline code overhauled
5254 Many generic problems with GDB's signal handling code have been fixed.
5255 These include: backtraces through non-contiguous stacks; recognition
5256 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5257 call; backtrace through a signal trampoline; step into and out of
5258 signal handlers; and single-stepping in the signal trampoline.
5260 Please note that kernel bugs are a limiting factor here. These
5261 features have been shown to work on an s390 GNU/Linux system that
5262 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5264 * Cygwin support for DWARF 2 added.
5266 * New native configurations
5268 GNU/Linux/hppa hppa*-*-linux*
5269 OpenBSD/hppa hppa*-*-openbsd*
5270 OpenBSD/m68k m68*-*-openbsd*
5271 OpenBSD/m88k m88*-*-openbsd*
5272 OpenBSD/powerpc powerpc-*-openbsd*
5273 NetBSD/vax vax-*-netbsd*
5274 OpenBSD/vax vax-*-openbsd*
5276 * END-OF-LIFE frame compatibility module
5278 GDB's internal frame infrastructure has been completely rewritten.
5279 The new infrastructure making it possible to support key new features
5280 including DWARF 2 Call Frame Information. To aid in the task of
5281 migrating old configurations to this new infrastructure, a
5282 compatibility module, that allowed old configurations to continue to
5283 work, was also included.
5285 GDB 6.2 will be the last release to include this frame compatibility
5286 module. This change directly impacts the following configurations:
5296 Unless there is activity to revive these configurations, they will be
5297 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5299 * REMOVED configurations and files
5301 Sun 3, running SunOS 3 m68*-*-sunos3*
5302 Sun 3, running SunOS 4 m68*-*-sunos4*
5303 Sun 2, running SunOS 3 m68000-*-sunos3*
5304 Sun 2, running SunOS 4 m68000-*-sunos4*
5305 Motorola 680x0 running LynxOS m68*-*-lynxos*
5306 AT&T 3b1/Unix pc m68*-att-*
5307 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5308 decstation mips-dec-* mips-little-*
5309 riscos mips-*-riscos* mips-*-sysv*
5310 sonymips mips-sony-*
5311 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5313 *** Changes in GDB 6.1.1:
5315 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5317 The TUI (Text-mode User Interface) is now built as part of a default
5318 GDB configuration. It is enabled by either selecting the TUI with the
5319 command line option "-i=tui" or by running the separate "gdbtui"
5320 program. For more information on the TUI, see the manual "Debugging
5323 * Pending breakpoint support (also included in GDB 6.1)
5325 Support has been added to allow you to specify breakpoints in shared
5326 libraries that have not yet been loaded. If a breakpoint location
5327 cannot be found, and the "breakpoint pending" option is set to auto,
5328 GDB queries you if you wish to make the breakpoint pending on a future
5329 shared-library load. If and when GDB resolves the breakpoint symbol,
5330 the pending breakpoint is removed as one or more regular breakpoints
5333 Pending breakpoints are very useful for GCJ Java debugging.
5335 * Fixed ISO-C build problems
5337 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5338 non ISO-C code that stopped them being built using a more strict ISO-C
5339 compiler (e.g., IBM's C compiler).
5341 * Fixed build problem on IRIX 5
5343 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5344 wasn't able to compile compile on an IRIX 5 system.
5346 * Added execute permission to gdb/gdbserver/configure
5348 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5349 permission. This bug would cause configure to fail on a number of
5350 systems (Solaris, IRIX). Ref: server/519.
5352 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5354 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5355 has been updated to use constant array sizes.
5357 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5359 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5360 its generated DWARF Call Frame Info. This encoding was causing GDB to
5361 panic, that panic has been fixed. Ref: gdb/1628.
5363 * Fixed a problem when examining parameters in shared library code.
5365 When examining parameters in optimized shared library code generated
5366 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5367 not available''. GDB now correctly displays the variable's value.
5369 *** Changes in GDB 6.1:
5371 * Removed --with-mmalloc
5373 Support for the mmalloc memory manager has been removed, as it
5374 conflicted with the internal gdb byte cache.
5376 * Changes in AMD64 configurations
5378 The AMD64 target now includes the %cs and %ss registers. As a result
5379 the AMD64 remote protocol has changed; this affects the floating-point
5380 and SSE registers. If you rely on those registers for your debugging,
5381 you should upgrade gdbserver on the remote side.
5383 * Revised SPARC target
5385 The SPARC target has been completely revised, incorporating the
5386 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5387 support for LynxOS and SunOS 4 has been dropped. Calling functions
5388 from within GDB on operating systems with a non-executable stack
5389 (Solaris, OpenBSD) now works.
5393 GDB has a new C++ demangler which does a better job on the mangled
5394 names generated by current versions of g++. It also runs faster, so
5395 with this and other changes gdb should now start faster on large C++
5398 * DWARF 2 Location Expressions
5400 GDB support for location expressions has been extended to support function
5401 arguments and frame bases. Older versions of GDB could crash when they
5404 * C++ nested types and namespaces
5406 GDB's support for nested types and namespaces in C++ has been
5407 improved, especially if you use the DWARF 2 debugging format. (This
5408 is the default for recent versions of GCC on most platforms.)
5409 Specifically, if you have a class "Inner" defined within a class or
5410 namespace "Outer", then GDB realizes that the class's name is
5411 "Outer::Inner", not simply "Inner". This should greatly reduce the
5412 frequency of complaints about not finding RTTI symbols. In addition,
5413 if you are stopped at inside of a function defined within a namespace,
5414 GDB modifies its name lookup accordingly.
5416 * New native configurations
5418 NetBSD/amd64 x86_64-*-netbsd*
5419 OpenBSD/amd64 x86_64-*-openbsd*
5420 OpenBSD/alpha alpha*-*-openbsd*
5421 OpenBSD/sparc sparc-*-openbsd*
5422 OpenBSD/sparc64 sparc64-*-openbsd*
5424 * New debugging protocols
5426 M32R with SDI protocol m32r-*-elf*
5428 * "set prompt-escape-char" command deleted.
5430 The command "set prompt-escape-char" has been deleted. This command,
5431 and its very obscure effet on GDB's prompt, was never documented,
5432 tested, nor mentioned in the NEWS file.
5434 * OBSOLETE configurations and files
5436 Configurations that have been declared obsolete in this release have
5437 been commented out. Unless there is activity to revive these
5438 configurations, the next release of GDB will have their sources
5439 permanently REMOVED.
5441 Sun 3, running SunOS 3 m68*-*-sunos3*
5442 Sun 3, running SunOS 4 m68*-*-sunos4*
5443 Sun 2, running SunOS 3 m68000-*-sunos3*
5444 Sun 2, running SunOS 4 m68000-*-sunos4*
5445 Motorola 680x0 running LynxOS m68*-*-lynxos*
5446 AT&T 3b1/Unix pc m68*-att-*
5447 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5448 decstation mips-dec-* mips-little-*
5449 riscos mips-*-riscos* mips-*-sysv*
5450 sonymips mips-sony-*
5451 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5453 * REMOVED configurations and files
5455 SGI Irix-4.x mips-sgi-irix4 or iris4
5456 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5457 Z8000 simulator z8k-zilog-none or z8ksim
5458 Matsushita MN10200 w/simulator mn10200-*-*
5459 H8/500 simulator h8500-hitachi-hms or h8500hms
5460 HP/PA running BSD hppa*-*-bsd*
5461 HP/PA running OSF/1 hppa*-*-osf*
5462 HP/PA Pro target hppa*-*-pro*
5463 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5464 386BSD i[3456]86-*-bsd*
5465 Sequent family i[3456]86-sequent-sysv4*
5466 i[3456]86-sequent-sysv*
5467 i[3456]86-sequent-bsd*
5468 SPARC running LynxOS sparc-*-lynxos*
5469 SPARC running SunOS 4 sparc-*-sunos4*
5470 Tsqware Sparclet sparclet-*-*
5471 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5473 *** Changes in GDB 6.0:
5477 Support for debugging the Objective-C programming language has been
5478 integrated into GDB.
5480 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5482 DWARF 2's Call Frame Information makes available compiler generated
5483 information that more exactly describes the program's run-time stack.
5484 By using this information, GDB is able to provide more robust stack
5487 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5488 have been updated to use a new backtrace mechanism which includes
5489 DWARF 2 CFI support.
5493 GDB's remote protocol has been extended to include support for hosted
5494 file I/O (where the remote target uses GDB's file system). See GDB's
5495 remote protocol documentation for details.
5497 * All targets using the new architecture framework.
5499 All of GDB's targets have been updated to use the new internal
5500 architecture framework. The way is now open for future GDB releases
5501 to include cross-architecture native debugging support (i386 on amd64,
5504 * GNU/Linux's Thread Local Storage (TLS)
5506 GDB now includes support for for the GNU/Linux implementation of
5507 per-thread variables.
5509 * GNU/Linux's Native POSIX Thread Library (NPTL)
5511 GDB's thread code has been updated to work with either the new
5512 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5514 * Separate debug info.
5516 GDB, in conjunction with BINUTILS, now supports a mechanism for
5517 automatically loading debug information from a separate file. Instead
5518 of shipping full debug and non-debug versions of system libraries,
5519 system integrators can now instead ship just the stripped libraries
5520 and optional debug files.
5522 * DWARF 2 Location Expressions
5524 DWARF 2 Location Expressions allow the compiler to more completely
5525 describe the location of variables (even in optimized code) to the
5528 GDB now includes preliminary support for location expressions (support
5529 for DW_OP_piece is still missing).
5533 A number of long standing bugs that caused GDB to die while starting a
5534 Java application have been fixed. GDB's Java support is now
5535 considered "useable".
5537 * GNU/Linux support for fork, vfork, and exec.
5539 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5540 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5543 * GDB supports logging output to a file
5545 There are two new commands, "set logging" and "show logging", which can be
5546 used to capture GDB's output to a file.
5548 * The meaning of "detach" has changed for gdbserver
5550 The "detach" command will now resume the application, as documented. To
5551 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5554 * d10v, m68hc11 `regs' command deprecated
5556 The `info registers' command has been updated so that it displays the
5557 registers using a format identical to the old `regs' command.
5561 A new command, "maint set profile on/off", has been added. This command can
5562 be used to enable or disable profiling while running GDB, to profile a
5563 session or a set of commands. In addition there is a new configure switch,
5564 "--enable-profiling", which will cause GDB to be compiled with profiling
5565 data, for more informative profiling results.
5567 * Default MI syntax changed to "mi2".
5569 The default MI (machine interface) syntax, enabled by the command line
5570 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5571 "mi1", can be enabled by specifying the option "-i=mi1".
5573 Support for the original "mi0" syntax (included in GDB 5.0) has been
5576 Fix for gdb/192: removed extraneous space when displaying frame level.
5577 Fix for gdb/672: update changelist is now output in mi list format.
5578 Fix for gdb/702: a -var-assign that updates the value now shows up
5579 in a subsequent -var-update.
5581 * New native configurations.
5583 FreeBSD/amd64 x86_64-*-freebsd*
5585 * Multi-arched targets.
5587 HP/PA HPUX11 hppa*-*-hpux*
5588 Renesas M32R/D w/simulator m32r-*-elf*
5590 * OBSOLETE configurations and files
5592 Configurations that have been declared obsolete in this release have
5593 been commented out. Unless there is activity to revive these
5594 configurations, the next release of GDB will have their sources
5595 permanently REMOVED.
5597 Z8000 simulator z8k-zilog-none or z8ksim
5598 Matsushita MN10200 w/simulator mn10200-*-*
5599 H8/500 simulator h8500-hitachi-hms or h8500hms
5600 HP/PA running BSD hppa*-*-bsd*
5601 HP/PA running OSF/1 hppa*-*-osf*
5602 HP/PA Pro target hppa*-*-pro*
5603 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5604 Sequent family i[3456]86-sequent-sysv4*
5605 i[3456]86-sequent-sysv*
5606 i[3456]86-sequent-bsd*
5607 Tsqware Sparclet sparclet-*-*
5608 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5610 * REMOVED configurations and files
5613 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5614 IBM AIX PS/2 i[3456]86-*-aix
5615 i386 running Mach 3.0 i[3456]86-*-mach3*
5616 i386 running Mach i[3456]86-*-mach*
5617 i386 running OSF/1 i[3456]86-*osf1mk*
5618 HP/Apollo 68k Family m68*-apollo*-sysv*,
5620 m68*-hp-bsd*, m68*-hp-hpux*
5621 Argonaut Risc Chip (ARC) arc-*-*
5622 Mitsubishi D30V d30v-*-*
5623 Fujitsu FR30 fr30-*-elf*
5624 OS/9000 i[34]86-*-os9k
5625 I960 with MON960 i960-*-coff
5627 * MIPS $fp behavior changed
5629 The convenience variable $fp, for the MIPS, now consistently returns
5630 the address of the current frame's base. Previously, depending on the
5631 context, $fp could refer to either $sp or the current frame's base
5632 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5633 The GNU Source-Level Debugger''.
5635 *** Changes in GDB 5.3:
5637 * GNU/Linux shared library multi-threaded performance improved.
5639 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5640 `/proc', in preference to `ptrace' for memory reads. This may result
5641 in an improvement in the start-up time of multi-threaded, shared
5642 library applications when run under GDB. One GDB user writes: ``loads
5643 shared libs like mad''.
5645 * ``gdbserver'' now supports multi-threaded applications on some targets
5647 Support for debugging multi-threaded applications which use
5648 the GNU/Linux LinuxThreads package has been added for
5649 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5650 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5652 * GDB now supports C/C++ preprocessor macros.
5654 GDB now expands preprocessor macro invocations in C/C++ expressions,
5655 and provides various commands for showing macro definitions and how
5658 The new command `macro expand EXPRESSION' expands any macro
5659 invocations in expression, and shows the result.
5661 The new command `show macro MACRO-NAME' shows the definition of the
5662 macro named MACRO-NAME, and where it was defined.
5664 Most compilers don't include information about macros in the debugging
5665 information by default. In GCC 3.1, for example, you need to compile
5666 your program with the options `-gdwarf-2 -g3'. If the macro
5667 information is present in the executable, GDB will read it.
5669 * Multi-arched targets.
5671 DEC Alpha (partial) alpha*-*-*
5672 DEC VAX (partial) vax-*-*
5674 National Semiconductor NS32000 (partial) ns32k-*-*
5675 Motorola 68000 (partial) m68k-*-*
5676 Motorola MCORE mcore-*-*
5680 Fujitsu FRV architecture added by Red Hat frv*-*-*
5683 * New native configurations
5685 Alpha NetBSD alpha*-*-netbsd*
5686 SH NetBSD sh*-*-netbsdelf*
5687 MIPS NetBSD mips*-*-netbsd*
5688 UltraSPARC NetBSD sparc64-*-netbsd*
5690 * OBSOLETE configurations and files
5692 Configurations that have been declared obsolete in this release have
5693 been commented out. Unless there is activity to revive these
5694 configurations, the next release of GDB will have their sources
5695 permanently REMOVED.
5697 Mitsubishi D30V d30v-*-*
5698 OS/9000 i[34]86-*-os9k
5699 IBM AIX PS/2 i[3456]86-*-aix
5700 Fujitsu FR30 fr30-*-elf*
5701 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5702 Argonaut Risc Chip (ARC) arc-*-*
5703 i386 running Mach 3.0 i[3456]86-*-mach3*
5704 i386 running Mach i[3456]86-*-mach*
5705 i386 running OSF/1 i[3456]86-*osf1mk*
5706 HP/Apollo 68k Family m68*-apollo*-sysv*,
5708 m68*-hp-bsd*, m68*-hp-hpux*
5709 I960 with MON960 i960-*-coff
5711 * OBSOLETE languages
5713 CHILL, a Pascal like language used by telecommunications companies.
5715 * REMOVED configurations and files
5717 AMD 29k family via UDI a29k-amd-udi, udi29k
5718 A29K VxWorks a29k-*-vxworks
5719 AMD 29000 embedded, using EBMON a29k-none-none
5720 AMD 29000 embedded with COFF a29k-none-coff
5721 AMD 29000 embedded with a.out a29k-none-aout
5723 testsuite/gdb.hp/gdb.threads-hp/ directory
5725 * New command "set max-user-call-depth <nnn>"
5727 This command allows the user to limit the call depth of user-defined
5728 commands. The default is 1024.
5730 * Changes in FreeBSD/i386 native debugging.
5732 Support for the "generate-core-file" has been added.
5734 * New commands "dump", "append", and "restore".
5736 These commands allow data to be copied from target memory
5737 to a bfd-format or binary file (dump and append), and back
5738 from a file into memory (restore).
5740 * Improved "next/step" support on multi-processor Alpha Tru64.
5742 The previous single-step mechanism could cause unpredictable problems,
5743 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5744 of a software single-step mechanism prevents this.
5746 *** Changes in GDB 5.2.1:
5754 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5755 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5756 Fix, by Joel Brobecker imported from mainline.
5758 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5759 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5760 Fix, by Fred Fish, imported from mainline.
5762 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5763 Surprisingly enough, it works now.
5764 By Michal Ludvig, imported from mainline.
5766 i386 hardware watchpoint support:
5767 avoid misses on second run for some targets.
5768 By Pierre Muller, imported from mainline.
5770 *** Changes in GDB 5.2:
5772 * New command "set trust-readonly-sections on[off]".
5774 This command is a hint that tells gdb that read-only sections
5775 really are read-only (ie. that their contents will not change).
5776 In this mode, gdb will go to the object file rather than the
5777 target to read memory from read-only sections (such as ".text").
5778 This can be a significant performance improvement on some
5779 (notably embedded) targets.
5781 * New command "generate-core-file" (or "gcore").
5783 This new gdb command allows the user to drop a core file of the child
5784 process state at any time. So far it's been implemented only for
5785 GNU/Linux and Solaris, but should be relatively easily ported to other
5786 hosts. Argument is core file name (defaults to core.<pid>).
5788 * New command line option
5790 GDB now accepts --pid or -p followed by a process id.
5792 * Change in command line behavior -- corefiles vs. process ids.
5794 There is a subtle behavior in the way in which GDB handles
5795 command line arguments. The first non-flag argument is always
5796 a program to debug, but the second non-flag argument may either
5797 be a corefile or a process id. Previously, GDB would attempt to
5798 open the second argument as a corefile, and if that failed, would
5799 issue a superfluous error message and then attempt to attach it as
5800 a process. Now, if the second argument begins with a non-digit,
5801 it will be treated as a corefile. If it begins with a digit,
5802 GDB will attempt to attach it as a process, and if no such process
5803 is found, will then attempt to open it as a corefile.
5805 * Changes in ARM configurations.
5807 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5808 configuration is fully multi-arch.
5810 * New native configurations
5812 ARM NetBSD arm*-*-netbsd*
5813 x86 OpenBSD i[3456]86-*-openbsd*
5814 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5815 Sparc64 running FreeBSD sparc64-*-freebsd*
5819 Sanyo XStormy16 xstormy16-elf
5821 * OBSOLETE configurations and files
5823 Configurations that have been declared obsolete in this release have
5824 been commented out. Unless there is activity to revive these
5825 configurations, the next release of GDB will have their sources
5826 permanently REMOVED.
5828 AMD 29k family via UDI a29k-amd-udi, udi29k
5829 A29K VxWorks a29k-*-vxworks
5830 AMD 29000 embedded, using EBMON a29k-none-none
5831 AMD 29000 embedded with COFF a29k-none-coff
5832 AMD 29000 embedded with a.out a29k-none-aout
5834 testsuite/gdb.hp/gdb.threads-hp/ directory
5836 * REMOVED configurations and files
5838 TI TMS320C80 tic80-*-*
5840 PowerPC Solaris powerpcle-*-solaris*
5841 PowerPC Windows NT powerpcle-*-cygwin32
5842 PowerPC Netware powerpc-*-netware*
5843 Harris/CXUX m88k m88*-harris-cxux*
5844 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5845 ns32k-utek-sysv* ns32k-utek-*
5846 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5847 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5848 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5849 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5850 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5852 * Changes to command line processing
5854 The new `--args' feature can be used to specify command-line arguments
5855 for the inferior from gdb's command line.
5857 * Changes to key bindings
5859 There is a new `operate-and-get-next' function bound to `C-o'.
5861 *** Changes in GDB 5.1.1
5863 Fix compile problem on DJGPP.
5865 Fix a problem with floating-point registers on the i386 being
5868 Fix to stop GDB crashing on .debug_str debug info.
5870 Numerous documentation fixes.
5872 Numerous testsuite fixes.
5874 *** Changes in GDB 5.1:
5876 * New native configurations
5878 Alpha FreeBSD alpha*-*-freebsd*
5879 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5880 MIPS GNU/Linux mips*-*-linux*
5881 MIPS SGI Irix 6.x mips*-sgi-irix6*
5882 ia64 AIX ia64-*-aix*
5883 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5887 Motorola 68HC11 and 68HC12 m68hc11-elf
5889 UltraSparc running GNU/Linux sparc64-*-linux*
5891 * OBSOLETE configurations and files
5893 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5894 Harris/CXUX m88k m88*-harris-cxux*
5895 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5896 ns32k-utek-sysv* ns32k-utek-*
5897 TI TMS320C80 tic80-*-*
5899 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5900 PowerPC Solaris powerpcle-*-solaris*
5901 PowerPC Windows NT powerpcle-*-cygwin32
5902 PowerPC Netware powerpc-*-netware*
5903 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5904 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5905 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5906 Apple Macintosh (MPW) host N/A
5908 stuff.c (Program to stuff files into a specially prepared space in kdb)
5909 kdb-start.c (Main loop for the standalone kernel debugger)
5911 Configurations that have been declared obsolete in this release have
5912 been commented out. Unless there is activity to revive these
5913 configurations, the next release of GDB will have their sources
5914 permanently REMOVED.
5916 * REMOVED configurations and files
5918 Altos 3068 m68*-altos-*
5919 Convex c1-*-*, c2-*-*
5921 ARM RISCix arm-*-* (as host)
5925 * GDB has been converted to ISO C.
5927 GDB's source code has been converted to ISO C. In particular, the
5928 sources are fully protoized, and rely on standard headers being
5933 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5935 * The MI enabled by default.
5937 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5938 revised and enabled by default. Packages which use GDB as a debugging
5939 engine behind a UI or another front end are encouraged to switch to
5940 using the GDB/MI interface, instead of the old annotations interface
5941 which is now deprecated.
5943 * Support for debugging Pascal programs.
5945 GDB now includes support for debugging Pascal programs. The following
5946 main features are supported:
5948 - Pascal-specific data types such as sets;
5950 - automatic recognition of Pascal sources based on file-name
5953 - Pascal-style display of data types, variables, and functions;
5955 - a Pascal expression parser.
5957 However, some important features are not yet supported.
5959 - Pascal string operations are not supported at all;
5961 - there are some problems with boolean types;
5963 - Pascal type hexadecimal constants are not supported
5964 because they conflict with the internal variables format;
5966 - support for Pascal objects and classes is not full yet;
5968 - unlike Pascal, GDB is case-sensitive for symbol names.
5970 * Changes in completion.
5972 Commands such as `shell', `run' and `set args', which pass arguments
5973 to inferior programs, now complete on file names, similar to what
5974 users expect at the shell prompt.
5976 Commands which accept locations, such as `disassemble', `print',
5977 `breakpoint', `until', etc. now complete on filenames as well as
5978 program symbols. Thus, if you type "break foob TAB", and the source
5979 files linked into the programs include `foobar.c', that file name will
5980 be one of the candidates for completion. However, file names are not
5981 considered for completion after you typed a colon that delimits a file
5982 name from a name of a function in that file, as in "break foo.c:bar".
5984 `set demangle-style' completes on available demangling styles.
5986 * New platform-independent commands:
5988 It is now possible to define a post-hook for a command as well as a
5989 hook that runs before the command. For more details, see the
5990 documentation of `hookpost' in the GDB manual.
5992 * Changes in GNU/Linux native debugging.
5994 Support for debugging multi-threaded programs has been completely
5995 revised for all platforms except m68k and sparc. You can now debug as
5996 many threads as your system allows you to have.
5998 Attach/detach is supported for multi-threaded programs.
6000 Support for SSE registers was added for x86. This doesn't work for
6001 multi-threaded programs though.
6003 * Changes in MIPS configurations.
6005 Multi-arch support is enabled for all MIPS configurations.
6007 GDB can now be built as native debugger on SGI Irix 6.x systems for
6008 debugging n32 executables. (Debugging 64-bit executables is not yet
6011 * Unified support for hardware watchpoints in all x86 configurations.
6013 Most (if not all) native x86 configurations support hardware-assisted
6014 breakpoints and watchpoints in a unified manner. This support
6015 implements debug register sharing between watchpoints, which allows to
6016 put a virtually infinite number of watchpoints on the same address,
6017 and also supports watching regions up to 16 bytes with several debug
6020 The new maintenance command `maintenance show-debug-regs' toggles
6021 debugging print-outs in functions that insert, remove, and test
6022 watchpoints and hardware breakpoints.
6024 * Changes in the DJGPP native configuration.
6026 New command ``info dos sysinfo'' displays assorted information about
6027 the CPU, OS, memory, and DPMI server.
6029 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6030 display information about segment descriptors stored in GDT, LDT, and
6033 New commands ``info dos pde'' and ``info dos pte'' display entries
6034 from Page Directory and Page Tables (for now works with CWSDPMI only).
6035 New command ``info dos address-pte'' displays the Page Table entry for
6036 a given linear address.
6038 GDB can now pass command lines longer than 126 characters to the
6039 program being debugged (requires an update to the libdbg.a library
6040 which is part of the DJGPP development kit).
6042 DWARF2 debug info is now supported.
6044 It is now possible to `step' and `next' through calls to `longjmp'.
6046 * Changes in documentation.
6048 All GDB documentation was converted to GFDL, the GNU Free
6049 Documentation License.
6051 Tracepoints-related commands are now fully documented in the GDB
6054 TUI, the Text-mode User Interface, is now documented in the manual.
6056 Tracepoints-related commands are now fully documented in the GDB
6059 The "GDB Internals" manual now has an index. It also includes
6060 documentation of `ui_out' functions, GDB coding standards, x86
6061 hardware watchpoints, and memory region attributes.
6063 * GDB's version number moved to ``version.in''
6065 The Makefile variable VERSION has been replaced by the file
6066 ``version.in''. People creating GDB distributions should update the
6067 contents of this file.
6071 GUD support is now a standard part of the EMACS distribution.
6073 *** Changes in GDB 5.0:
6075 * Improved support for debugging FP programs on x86 targets
6077 Unified and much-improved support for debugging floating-point
6078 programs on all x86 targets. In particular, ``info float'' now
6079 displays the FP registers in the same format on all x86 targets, with
6080 greater level of detail.
6082 * Improvements and bugfixes in hardware-assisted watchpoints
6084 It is now possible to watch array elements, struct members, and
6085 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6086 on x86 targets no longer erroneously trigger when the address is
6089 * Improvements in the native DJGPP version of GDB
6091 The distribution now includes all the scripts and auxiliary files
6092 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6093 machines ``out of the box''.
6095 The DJGPP version can now debug programs that use signals. It is
6096 possible to catch signals that happened in the debuggee, deliver
6097 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6098 would kill the program being debugged.) Programs that hook hardware
6099 interrupts (keyboard, timer, etc.) can also be debugged.
6101 It is now possible to debug DJGPP programs that redirect their
6102 standard handles or switch them to raw (as opposed to cooked) mode, or
6103 even close them. The command ``run < foo > bar'' works as expected,
6104 and ``info terminal'' reports useful information about the debuggee's
6105 terminal, including raw/cooked mode, redirection, etc.
6107 The DJGPP version now uses termios functions for console I/O, which
6108 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6111 DOS-style file names with drive letters are now fully supported by
6114 It is now possible to debug DJGPP programs that switch their working
6115 directory. It is also possible to rerun the debuggee any number of
6116 times without restarting GDB; thus, you can use the same setup,
6117 breakpoints, etc. for many debugging sessions.
6119 * New native configurations
6121 ARM GNU/Linux arm*-*-linux*
6122 PowerPC GNU/Linux powerpc-*-linux*
6126 Motorola MCore mcore-*-*
6127 x86 VxWorks i[3456]86-*-vxworks*
6128 PowerPC VxWorks powerpc-*-vxworks*
6129 TI TMS320C80 tic80-*-*
6131 * OBSOLETE configurations
6133 Altos 3068 m68*-altos-*
6134 Convex c1-*-*, c2-*-*
6136 ARM RISCix arm-*-* (as host)
6139 Configurations that have been declared obsolete will be commented out,
6140 but the code will be left in place. If there is no activity to revive
6141 these configurations before the next release of GDB, the sources will
6142 be permanently REMOVED.
6144 * Gould support removed
6146 Support for the Gould PowerNode and NP1 has been removed.
6148 * New features for SVR4
6150 On SVR4 native platforms (such as Solaris), if you attach to a process
6151 without first loading a symbol file, GDB will now attempt to locate and
6152 load symbols from the running process's executable file.
6154 * Many C++ enhancements
6156 C++ support has been greatly improved. Overload resolution now works properly
6157 in almost all cases. RTTI support is on the way.
6159 * Remote targets can connect to a sub-program
6161 A popen(3) style serial-device has been added. This device starts a
6162 sub-process (such as a stand-alone simulator) and then communicates
6163 with that. The sub-program to run is specified using the syntax
6164 ``|<program> <args>'' vis:
6166 (gdb) set remotedebug 1
6167 (gdb) target extended-remote |mn10300-elf-sim program-args
6169 * MIPS 64 remote protocol
6171 A long standing bug in the mips64 remote protocol where by GDB
6172 expected certain 32 bit registers (ex SR) to be transfered as 32
6173 instead of 64 bits has been fixed.
6175 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6176 added to provide backward compatibility with older versions of GDB.
6178 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6180 The command ``set remotebinarydownload'' command has been replaced by
6181 ``set remote X-packet''. Other commands in ``set remote'' family
6182 include ``set remote P-packet''.
6184 * Breakpoint commands accept ranges.
6186 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6187 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6188 ``tracepoint passcount'' also accepts a range of tracepoints.
6190 * ``apropos'' command added.
6192 The ``apropos'' command searches through command names and
6193 documentation strings, printing out matches, making it much easier to
6194 try to find a command that does what you are looking for.
6198 A new machine oriented interface (MI) has been added to GDB. This
6199 interface is designed for debug environments running GDB as a separate
6200 process. This is part of the long term libGDB project. See the
6201 "GDB/MI" chapter of the GDB manual for further information. It can be
6202 enabled by configuring with:
6204 .../configure --enable-gdbmi
6206 *** Changes in GDB-4.18:
6208 * New native configurations
6210 HP-UX 10.20 hppa*-*-hpux10.20
6211 HP-UX 11.x hppa*-*-hpux11.0*
6212 M68K GNU/Linux m68*-*-linux*
6216 Fujitsu FR30 fr30-*-elf*
6217 Intel StrongARM strongarm-*-*
6218 Mitsubishi D30V d30v-*-*
6220 * OBSOLETE configurations
6222 Gould PowerNode, NP1 np1-*-*, pn-*-*
6224 Configurations that have been declared obsolete will be commented out,
6225 but the code will be left in place. If there is no activity to revive
6226 these configurations before the next release of GDB, the sources will
6227 be permanently REMOVED.
6231 As a compatibility experiment, GDB's source files buildsym.h and
6232 buildsym.c have been converted to pure standard C, no longer
6233 containing any K&R compatibility code. We believe that all systems in
6234 use today either come with a standard C compiler, or have a GCC port
6235 available. If this is not true, please report the affected
6236 configuration to bug-gdb@gnu.org immediately. See the README file for
6237 information about getting a standard C compiler if you don't have one
6242 GDB now uses readline 2.2.
6244 * set extension-language
6246 You can now control the mapping between filename extensions and source
6247 languages by using the `set extension-language' command. For instance,
6248 you can ask GDB to treat .c files as C++ by saying
6249 set extension-language .c c++
6250 The command `info extensions' lists all of the recognized extensions
6251 and their associated languages.
6253 * Setting processor type for PowerPC and RS/6000
6255 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6256 you can use the `set processor' command to specify what variant of the
6257 PowerPC family you are debugging. The command
6261 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6262 following PowerPC and RS6000 variants:
6264 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6265 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6267 403GC IBM PowerPC 403GC
6268 505 Motorola PowerPC 505
6269 860 Motorola PowerPC 860 or 850
6270 601 Motorola PowerPC 601
6271 602 Motorola PowerPC 602
6272 603 Motorola/IBM PowerPC 603 or 603e
6273 604 Motorola PowerPC 604 or 604e
6274 750 Motorola/IBM PowerPC 750 or 750
6276 At the moment, this command just tells GDB what to name the
6277 special-purpose processor registers. Since almost all the affected
6278 registers are inaccessible to user-level programs, this command is
6279 only useful for remote debugging in its present form.
6283 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6284 more extensive support for HP-UX. Added features include shared
6285 library support, kernel threads and hardware watchpoints for 11.00,
6286 support for HP's ANSI C and C++ compilers, and a compatibility mode
6287 for xdb and dbx commands.
6291 HP's donation includes the new concept of catchpoints, which is a
6292 generalization of the old catch command. On HP-UX, it is now possible
6293 to catch exec, fork, and vfork, as well as library loading.
6295 This means that the existing catch command has changed; its first
6296 argument now specifies the type of catch to be set up. See the
6297 output of "help catch" for a list of catchpoint types.
6299 * Debugging across forks
6301 On HP-UX, you can choose which process to debug when a fork() happens
6306 HP has donated a curses-based terminal user interface (TUI). To get
6307 it, build with --enable-tui. Although this can be enabled for any
6308 configuration, at present it only works for native HP debugging.
6310 * GDB remote protocol additions
6312 A new protocol packet 'X' that writes binary data is now available.
6313 Default behavior is to try 'X', then drop back to 'M' if the stub
6314 fails to respond. The settable variable `remotebinarydownload'
6315 allows explicit control over the use of 'X'.
6317 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6318 full 64-bit address. The command
6320 set remoteaddresssize 32
6322 can be used to revert to the old behaviour. For existing remote stubs
6323 the change should not be noticed, as the additional address information
6326 In order to assist in debugging stubs, you may use the maintenance
6327 command `packet' to send any text string to the stub. For instance,
6329 maint packet heythere
6331 sends the packet "$heythere#<checksum>". Note that it is very easy to
6332 disrupt a debugging session by sending the wrong packet at the wrong
6335 The compare-sections command allows you to compare section data on the
6336 target to what is in the executable file without uploading or
6337 downloading, by comparing CRC checksums.
6339 * Tracing can collect general expressions
6341 You may now collect general expressions at tracepoints. This requires
6342 further additions to the target-side stub; see tracepoint.c and
6343 doc/agentexpr.texi for further details.
6345 * mask-address variable for Mips
6347 For Mips targets, you may control the zeroing of the upper 32 bits of
6348 a 64-bit address by entering `set mask-address on'. This is mainly
6349 of interest to users of embedded R4xxx and R5xxx processors.
6351 * Higher serial baud rates
6353 GDB's serial code now allows you to specify baud rates 57600, 115200,
6354 230400, and 460800 baud. (Note that your host system may not be able
6355 to achieve all of these rates.)
6359 The i960 configuration now includes an initial implementation of a
6360 builtin simulator, contributed by Jim Wilson.
6363 *** Changes in GDB-4.17:
6365 * New native configurations
6367 Alpha GNU/Linux alpha*-*-linux*
6368 Unixware 2.x i[3456]86-unixware2*
6369 Irix 6.x mips*-sgi-irix6*
6370 PowerPC GNU/Linux powerpc-*-linux*
6371 PowerPC Solaris powerpcle-*-solaris*
6372 Sparc GNU/Linux sparc-*-linux*
6373 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6377 Argonaut Risc Chip (ARC) arc-*-*
6378 Hitachi H8/300S h8300*-*-*
6379 Matsushita MN10200 w/simulator mn10200-*-*
6380 Matsushita MN10300 w/simulator mn10300-*-*
6381 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6382 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6383 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6384 Mitsubishi D10V w/simulator d10v-*-*
6385 Mitsubishi M32R/D w/simulator m32r-*-elf*
6386 Tsqware Sparclet sparclet-*-*
6387 NEC V850 w/simulator v850-*-*
6389 * New debugging protocols
6391 ARM with RDI protocol arm*-*-*
6392 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6393 DDB and LSI variants of PMON protocol mips*-*-*
6394 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6395 PowerPC with SDS protocol powerpc{,le}-*-eabi
6396 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6400 All configurations can now understand and use the DWARF 2 debugging
6401 format. The choice is automatic, if the symbol file contains DWARF 2
6406 GDB now includes basic Java language support. This support is
6407 only useful with Java compilers that produce native machine code.
6409 * solib-absolute-prefix and solib-search-path
6411 For SunOS and SVR4 shared libraries, you may now set the prefix for
6412 loading absolute shared library symbol files, and the search path for
6413 locating non-absolute shared library symbol files.
6415 * Live range splitting
6417 GDB can now effectively debug code for which GCC has performed live
6418 range splitting as part of its optimization. See gdb/doc/LRS for
6419 more details on the expected format of the stabs information.
6423 GDB's support for the GNU Hurd, including thread debugging, has been
6424 updated to work with current versions of the Hurd.
6428 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6429 instruction set. ARM GDB automatically detects when Thumb
6430 instructions are in use, and adjusts disassembly and backtracing
6435 GDB's MIPS target configurations now handle the MIP16 16-bit
6440 GDB now includes support for overlays; if an executable has been
6441 linked such that multiple sections are based at the same address, GDB
6442 will decide which section to use for symbolic info. You can choose to
6443 control the decision manually, using overlay commands, or implement
6444 additional target-side support and use "overlay load-target" to bring
6445 in the overlay mapping. Do "help overlay" for more detail.
6449 The command "info symbol <address>" displays information about
6450 the symbol at the specified address.
6454 The standard remote protocol now includes an extension that allows
6455 asynchronous collection and display of trace data. This requires
6456 extensive support in the target-side debugging stub. Tracing mode
6457 includes a new interaction mode in GDB and new commands: see the
6458 file tracepoint.c for more details.
6462 Configurations for embedded MIPS now include a simulator contributed
6463 by Cygnus Solutions. The simulator supports the instruction sets
6464 of most MIPS variants.
6468 Sparc configurations may now include the ERC32 simulator contributed
6469 by the European Space Agency. The simulator is not built into
6470 Sparc targets by default; configure with --enable-sim to include it.
6474 For target configurations that may include multiple variants of a
6475 basic architecture (such as MIPS and SH), you may now set the
6476 architecture explicitly. "set arch" sets, "info arch" lists
6477 the possible architectures.
6479 *** Changes in GDB-4.16:
6481 * New native configurations
6483 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6484 M68K NetBSD m68k-*-netbsd*
6485 PowerPC AIX 4.x powerpc-*-aix*
6486 PowerPC MacOS powerpc-*-macos*
6487 PowerPC Windows NT powerpcle-*-cygwin32
6488 RS/6000 AIX 4.x rs6000-*-aix4*
6492 ARM with RDP protocol arm-*-*
6493 I960 with MON960 i960-*-coff
6494 MIPS VxWorks mips*-*-vxworks*
6495 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6496 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6498 Matra Sparclet sparclet-*-*
6502 The powerpc-eabi configuration now includes the PSIM simulator,
6503 contributed by Andrew Cagney, with assistance from Mike Meissner.
6504 PSIM is a very elaborate model of the PowerPC, including not only
6505 basic instruction set execution, but also details of execution unit
6506 performance and I/O hardware. See sim/ppc/README for more details.
6510 GDB now works with Solaris 2.5.
6512 * Windows 95/NT native
6514 GDB will now work as a native debugger on Windows 95 and Windows NT.
6515 To build it from source, you must use the "gnu-win32" environment,
6516 which uses a DLL to emulate enough of Unix to run the GNU tools.
6517 Further information, binaries, and sources are available at
6518 ftp.cygnus.com, under pub/gnu-win32.
6520 * dont-repeat command
6522 If a user-defined command includes the command `dont-repeat', then the
6523 command will not be repeated if the user just types return. This is
6524 useful if the command is time-consuming to run, so that accidental
6525 extra keystrokes don't run the same command many times.
6527 * Send break instead of ^C
6529 The standard remote protocol now includes an option to send a break
6530 rather than a ^C to the target in order to interrupt it. By default,
6531 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6533 * Remote protocol timeout
6535 The standard remote protocol includes a new variable `remotetimeout'
6536 that allows you to set the number of seconds before GDB gives up trying
6537 to read from the target. The default value is 2.
6539 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6541 By default GDB will automatically keep track of objects as they are
6542 loaded and unloaded by the dynamic linker. By using the command `set
6543 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6544 when shared library events occur, thus allowing you to set breakpoints
6545 in shared libraries which are explicitly loaded by the inferior.
6547 Note this feature does not work on hpux8. On hpux9 you must link
6548 /usr/lib/end.o into your program. This feature should work
6549 automatically on hpux10.
6551 * Irix 5.x hardware watchpoint support
6553 Irix 5 configurations now support the use of hardware watchpoints.
6555 * Mips protocol "SYN garbage limit"
6557 When debugging a Mips target using the `target mips' protocol, you
6558 may set the number of characters that GDB will ignore by setting
6559 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6560 every character. The default value is 1050.
6562 * Recording and replaying remote debug sessions
6564 If you set `remotelogfile' to the name of a file, gdb will write to it
6565 a recording of a remote debug session. This recording may then be
6566 replayed back to gdb using "gdbreplay". See gdbserver/README for
6567 details. This is useful when you have a problem with GDB while doing
6568 remote debugging; you can make a recording of the session and send it
6569 to someone else, who can then recreate the problem.
6571 * Speedups for remote debugging
6573 GDB includes speedups for downloading and stepping MIPS systems using
6574 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6575 and more efficient S-record downloading.
6577 * Memory use reductions and statistics collection
6579 GDB now uses less memory and reports statistics about memory usage.
6580 Try the `maint print statistics' command, for example.
6582 *** Changes in GDB-4.15:
6584 * Psymtabs for XCOFF
6586 The symbol reader for AIX GDB now uses partial symbol tables. This
6587 can greatly improve startup time, especially for large executables.
6589 * Remote targets use caching
6591 Remote targets now use a data cache to speed up communication with the
6592 remote side. The data cache could lead to incorrect results because
6593 it doesn't know about volatile variables, thus making it impossible to
6594 debug targets which use memory mapped I/O devices. `set remotecache
6595 off' turns the the data cache off.
6597 * Remote targets may have threads
6599 The standard remote protocol now includes support for multiple threads
6600 in the target system, using new protocol commands 'H' and 'T'. See
6601 gdb/remote.c for details.
6605 If GDB is configured with `--enable-netrom', then it will include
6606 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6607 acts as though it is a bank of ROM on the target board, but you can
6608 write into it over the network. GDB's support consists only of
6609 support for fast loading into the emulated ROM; to debug, you must use
6610 another protocol, such as standard remote protocol. The usual
6611 sequence is something like
6613 target nrom <netrom-hostname>
6615 target remote <netrom-hostname>:1235
6619 GDB now includes support for the Apple Macintosh, as a host only. It
6620 may be run as either an MPW tool or as a standalone application, and
6621 it can debug through the serial port. All the usual GDB commands are
6622 available, but to the target command, you must supply "serial" as the
6623 device type instead of "/dev/ttyXX". See mpw-README in the main
6624 directory for more information on how to build. The MPW configuration
6625 scripts */mpw-config.in support only a few targets, and only the
6626 mips-idt-ecoff target has been tested.
6630 GDB configuration now uses autoconf. This is not user-visible,
6631 but does simplify configuration and building.
6635 GDB now supports hpux10.
6637 *** Changes in GDB-4.14:
6639 * New native configurations
6641 x86 FreeBSD i[345]86-*-freebsd
6642 x86 NetBSD i[345]86-*-netbsd
6643 NS32k NetBSD ns32k-*-netbsd
6644 Sparc NetBSD sparc-*-netbsd
6648 A29K VxWorks a29k-*-vxworks
6649 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6650 CPU32 EST-300 emulator m68*-*-est*
6651 PowerPC ELF powerpc-*-elf
6654 * Alpha OSF/1 support for procfs
6656 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6657 possible to attach to running processes. As the mounting of the /proc
6658 filesystem is optional on the Alpha, GDB automatically determines
6659 the availability of /proc during startup. This can lead to problems
6660 if /proc is unmounted after GDB has been started.
6662 * Arguments to user-defined commands
6664 User commands may accept up to 10 arguments separated by whitespace.
6665 Arguments are accessed within the user command via $arg0..$arg9. A
6668 print $arg0 + $arg1 + $arg2
6670 To execute the command use:
6673 Defines the command "adder" which prints the sum of its three arguments.
6674 Note the arguments are text substitutions, so they may reference variables,
6675 use complex expressions, or even perform inferior function calls.
6677 * New `if' and `while' commands
6679 This makes it possible to write more sophisticated user-defined
6680 commands. Both commands take a single argument, which is the
6681 expression to evaluate, and must be followed by the commands to
6682 execute, one per line, if the expression is nonzero, the list being
6683 terminated by the word `end'. The `if' command list may include an
6684 `else' word, which causes the following commands to be executed only
6685 if the expression is zero.
6687 * Fortran source language mode
6689 GDB now includes partial support for Fortran 77. It will recognize
6690 Fortran programs and can evaluate a subset of Fortran expressions, but
6691 variables and functions may not be handled correctly. GDB will work
6692 with G77, but does not yet know much about symbols emitted by other
6695 * Better HPUX support
6697 Most debugging facilities now work on dynamic executables for HPPAs
6698 running hpux9 or later. You can attach to running dynamically linked
6699 processes, but by default the dynamic libraries will be read-only, so
6700 for instance you won't be able to put breakpoints in them. To change
6701 that behavior do the following before running the program:
6707 This will cause the libraries to be mapped private and read-write.
6708 To revert to the normal behavior, do this:
6714 You cannot set breakpoints or examine data in the library until after
6715 the library is loaded if the function/data symbols do not have
6718 GDB can now also read debug symbols produced by the HP C compiler on
6719 HPPAs (sorry, no C++, Fortran or 68k support).
6721 * Target byte order now dynamically selectable
6723 You can choose which byte order to use with a target system, via the
6724 commands "set endian big" and "set endian little", and you can see the
6725 current setting by using "show endian". You can also give the command
6726 "set endian auto", in which case GDB will use the byte order
6727 associated with the executable. Currently, only embedded MIPS
6728 configurations support dynamic selection of target byte order.
6730 * New DOS host serial code
6732 This version uses DPMI interrupts to handle buffered I/O, so you
6733 no longer need to run asynctsr when debugging boards connected to
6736 *** Changes in GDB-4.13:
6738 * New "complete" command
6740 This lists all the possible completions for the rest of the line, if it
6741 were to be given as a command itself. This is intended for use by emacs.
6743 * Trailing space optional in prompt
6745 "set prompt" no longer adds a space for you after the prompt you set. This
6746 allows you to set a prompt which ends in a space or one that does not.
6748 * Breakpoint hit counts
6750 "info break" now displays a count of the number of times the breakpoint
6751 has been hit. This is especially useful in conjunction with "ignore"; you
6752 can ignore a large number of breakpoint hits, look at the breakpoint info
6753 to see how many times the breakpoint was hit, then run again, ignoring one
6754 less than that number, and this will get you quickly to the last hit of
6757 * Ability to stop printing at NULL character
6759 "set print null-stop" will cause GDB to stop printing the characters of
6760 an array when the first NULL is encountered. This is useful when large
6761 arrays actually contain only short strings.
6763 * Shared library breakpoints
6765 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6766 breakpoints in shared libraries before the executable is run.
6768 * Hardware watchpoints
6770 There is a new hardware breakpoint for the watch command for sparclite
6771 targets. See gdb/sparclite/hw_breakpoint.note.
6773 Hardware watchpoints are also now supported under GNU/Linux.
6777 Annotations have been added. These are for use with graphical interfaces,
6778 and are still experimental. Currently only gdba.el uses these.
6780 * Improved Irix 5 support
6782 GDB now works properly with Irix 5.2.
6784 * Improved HPPA support
6786 GDB now works properly with the latest GCC and GAS.
6788 * New native configurations
6790 Sequent PTX4 i[34]86-sequent-ptx4
6791 HPPA running OSF/1 hppa*-*-osf*
6792 Atari TT running SVR4 m68*-*-sysv4*
6793 RS/6000 LynxOS rs6000-*-lynxos*
6797 OS/9000 i[34]86-*-os9k
6798 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6801 * Hitachi SH7000 and E7000-PC ICE support
6803 There is now support for communicating with the Hitachi E7000-PC ICE.
6804 This is available automatically when GDB is configured for the SH.
6808 As usual, a variety of small fixes and improvements, both generic
6809 and configuration-specific. See the ChangeLog for more detail.
6811 *** Changes in GDB-4.12:
6813 * Irix 5 is now supported
6817 GDB-4.12 on the HPPA has a number of changes which make it unable
6818 to debug the output from the currently released versions of GCC and
6819 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6820 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6821 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6824 *** Changes in GDB-4.11:
6826 * User visible changes:
6830 The "set remotedebug" option is now consistent between the mips remote
6831 target, remote targets using the gdb-specific protocol, UDI (AMD's
6832 debug protocol for the 29k) and the 88k bug monitor. It is now an
6833 integer specifying a debug level (normally 0 or 1, but 2 means more
6834 debugging info for the mips target).
6836 * DEC Alpha native support
6838 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6839 debug info, but GDB works fairly well with the DEC compiler and should
6840 work with a future GCC release. See the README file for a few
6841 Alpha-specific notes.
6843 * Preliminary thread implementation
6845 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6847 * LynxOS native and target support for 386
6849 This release has been hosted on LynxOS 2.2, and also can be configured
6850 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6853 * Improvements in C++ mangling/demangling.
6855 This release has much better g++ debugging, specifically in name
6856 mangling/demangling, virtual function calls, print virtual table,
6857 call methods, ...etc.
6859 *** Changes in GDB-4.10:
6861 * User visible changes:
6863 Remote debugging using the GDB-specific (`target remote') protocol now
6864 supports the `load' command. This is only useful if you have some
6865 other way of getting the stub to the target system, and you can put it
6866 somewhere in memory where it won't get clobbered by the download.
6868 Filename completion now works.
6870 When run under emacs mode, the "info line" command now causes the
6871 arrow to point to the line specified. Also, "info line" prints
6872 addresses in symbolic form (as well as hex).
6874 All vxworks based targets now support a user settable option, called
6875 vxworks-timeout. This option represents the number of seconds gdb
6876 should wait for responses to rpc's. You might want to use this if
6877 your vxworks target is, perhaps, a slow software simulator or happens
6878 to be on the far side of a thin network line.
6882 This release contains support for using a DEC alpha as a GDB host for
6883 cross debugging. Native alpha debugging is not supported yet.
6886 *** Changes in GDB-4.9:
6890 This is the first GDB release which is accompanied by a matching testsuite.
6891 The testsuite requires installation of dejagnu, which should be available
6892 via ftp from most sites that carry GNU software.
6896 'Cfront' style demangling has had its name changed to 'ARM' style, to
6897 emphasize that it was written from the specifications in the C++ Annotated
6898 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6899 disclaimers, it still generated too much confusion with users attempting to
6900 use gdb with AT&T cfront.
6904 GDB now uses a standard remote interface to a simulator library.
6905 So far, the library contains simulators for the Zilog Z8001/2, the
6906 Hitachi H8/300, H8/500 and Super-H.
6908 * New targets supported
6910 H8/300 simulator h8300-hitachi-hms or h8300hms
6911 H8/500 simulator h8500-hitachi-hms or h8500hms
6912 SH simulator sh-hitachi-hms or sh
6913 Z8000 simulator z8k-zilog-none or z8ksim
6914 IDT MIPS board over serial line mips-idt-ecoff
6916 Cross-debugging to GO32 targets is supported. It requires a custom
6917 version of the i386-stub.c module which is integrated with the
6918 GO32 memory extender.
6920 * New remote protocols
6922 MIPS remote debugging protocol.
6924 * New source languages supported
6926 This version includes preliminary support for Chill, a Pascal like language
6927 used by telecommunications companies. Chill support is also being integrated
6928 into the GNU compiler, but we don't know when it will be publically available.
6931 *** Changes in GDB-4.8:
6933 * HP Precision Architecture supported
6935 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6936 version of this support was available as a set of patches from the
6937 University of Utah. GDB does not support debugging of programs
6938 compiled with the HP compiler, because HP will not document their file
6939 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6940 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6942 Many problems in the preliminary version have been fixed.
6944 * Faster and better demangling
6946 We have improved template demangling and fixed numerous bugs in the GNU style
6947 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6948 character types (wchar_t) are now supported. Demangling of each symbol is now
6949 only done once, and is cached when the symbol table for a file is read in.
6950 This results in a small increase in memory usage for C programs, a moderate
6951 increase in memory usage for C++ programs, and a fantastic speedup in
6954 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6955 from the specifications in the Annotated Reference Manual, which AT&T's
6956 compiler does not actually implement.
6958 * G++ multiple inheritance compiler problem
6960 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6961 inheritance lattices was reworked to properly discover ambiguities. We
6962 recently found an example which causes this new algorithm to fail in a
6963 very subtle way, producing bad debug information for those classes.
6964 The file 'gcc.patch' (in this directory) can be applied to gcc to
6965 circumvent the problem. A future GCC release will contain a complete
6968 The previous G++ debug info problem (mentioned below for the gdb-4.7
6969 release) is fixed in gcc version 2.3.2.
6971 * Improved configure script
6973 The `configure' script will now attempt to guess your system type if
6974 you don't supply a host system type. The old scheme of supplying a
6975 host system triplet is preferable over using this. All the magic is
6976 done in the new `config.guess' script. Examine it for details.
6978 We have also brought our configure script much more in line with the FSF's
6979 version. It now supports the --with-xxx options. In particular,
6980 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6981 The resulting GDB will not be able to read arbitrary object file formats --
6982 only the format ``expected'' to be used on the configured target system.
6983 We hope to make this the default in a future release.
6985 * Documentation improvements
6987 There's new internal documentation on how to modify GDB, and how to
6988 produce clean changes to the code. We implore people to read it
6989 before submitting changes.
6991 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6992 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6993 `info' files are also provided. To build `info' files from scratch,
6994 you will need the latest `makeinfo' release, which will be available in
6995 a future texinfo-X.Y release.
6997 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6998 We're not sure exactly which versions have this problem, but it has
6999 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7000 or better. If that isn't possible, there is a patch in
7001 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7002 around this problem.
7006 GDB now supports array constants that can be used in expressions typed in by
7007 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7008 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7011 The new directory `gdb/sparclite' contains a program that demonstrates
7012 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7014 * New native hosts supported
7016 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7017 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7019 * New targets supported
7021 AMD 29k family via UDI a29k-amd-udi or udi29k
7023 * New file formats supported
7025 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7026 HPUX core files, and SCO 3.2v2 core files.
7030 Attaching to processes now works again; thanks for the many bug reports.
7032 We have also stomped on a bunch of core dumps caused by
7033 printf_filtered("%s") problems.
7035 We eliminated a copyright problem on the rpc and ptrace header files
7036 for VxWorks, which was discovered at the last minute during the 4.7
7037 release. You should now be able to build a VxWorks GDB.
7039 You can now interrupt gdb while an attached process is running. This
7040 will cause the attached process to stop, and give control back to GDB.
7042 We fixed problems caused by using too many file descriptors
7043 for reading symbols from object files and libraries. This was
7044 especially a problem for programs that used many (~100) shared
7047 The `step' command now only enters a subroutine if there is line number
7048 information for the subroutine. Otherwise it acts like the `next'
7049 command. Previously, `step' would enter subroutines if there was
7050 any debugging information about the routine. This avoids problems
7051 when using `cc -g1' on MIPS machines.
7053 * Internal improvements
7055 GDB's internal interfaces have been improved to make it easier to support
7056 debugging of multiple languages in the future.
7058 GDB now uses a common structure for symbol information internally.
7059 Minimal symbols (derived from linkage symbols in object files), partial
7060 symbols (from a quick scan of debug information), and full symbols
7061 contain a common subset of information, making it easier to write
7062 shared code that handles any of them.
7064 * New command line options
7066 We now accept --silent as an alias for --quiet.
7070 The memory-mapped-malloc library is now licensed under the GNU Library
7071 General Public License.
7073 *** Changes in GDB-4.7:
7075 * Host/native/target split
7077 GDB has had some major internal surgery to untangle the support for
7078 hosts and remote targets. Now, when you configure GDB for a remote
7079 target, it will no longer load in all of the support for debugging
7080 local programs on the host. When fully completed and tested, this will
7081 ensure that arbitrary host/target combinations are possible.
7083 The primary conceptual shift is to separate the non-portable code in
7084 GDB into three categories. Host specific code is required any time GDB
7085 is compiled on that host, regardless of the target. Target specific
7086 code relates to the peculiarities of the target, but can be compiled on
7087 any host. Native specific code is everything else: it can only be
7088 built when the host and target are the same system. Child process
7089 handling and core file support are two common `native' examples.
7091 GDB's use of /proc for controlling Unix child processes is now cleaner.
7092 It has been split out into a single module under the `target_ops' vector,
7093 plus two native-dependent functions for each system that uses /proc.
7095 * New hosts supported
7097 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7098 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7099 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7101 * New targets supported
7103 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7104 68030 and CPU32 m68030-*-*, m68332-*-*
7106 * New native hosts supported
7108 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7109 (386bsd is not well tested yet)
7110 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7112 * New file formats supported
7114 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7115 supports reading of `a.out.adobe' object files, which are an a.out
7116 format extended with minimal information about multiple sections.
7120 `show copying' is the same as the old `info copying'.
7121 `show warranty' is the same as `info warrantee'.
7122 These were renamed for consistency. The old commands continue to work.
7124 `info handle' is a new alias for `info signals'.
7126 You can now define pre-command hooks, which attach arbitrary command
7127 scripts to any command. The commands in the hook will be executed
7128 prior to the user's command. You can also create a hook which will be
7129 executed whenever the program stops. See gdb.texinfo.
7133 We now deal with Cfront style name mangling, and can even extract type
7134 info from mangled symbols. GDB can automatically figure out which
7135 symbol mangling style your C++ compiler uses.
7137 Calling of methods and virtual functions has been improved as well.
7141 The crash that occured when debugging Sun Ansi-C compiled binaries is
7142 fixed. This was due to mishandling of the extra N_SO stabs output
7145 We also finally got Ultrix 4.2 running in house, and fixed core file
7146 support, with help from a dozen people on the net.
7148 John M. Farrell discovered that the reason that single-stepping was so
7149 slow on all of the Mips based platforms (primarily SGI and DEC) was
7150 that we were trying to demangle and lookup a symbol used for internal
7151 purposes on every instruction that was being stepped through. Changing
7152 the name of that symbol so that it couldn't be mistaken for a C++
7153 mangled symbol sped things up a great deal.
7155 Rich Pixley sped up symbol lookups in general by getting much smarter
7156 about when C++ symbol mangling is necessary. This should make symbol
7157 completion (TAB on the command line) much faster. It's not as fast as
7158 we'd like, but it's significantly faster than gdb-4.6.
7162 A new user controllable variable 'call_scratch_address' can
7163 specify the location of a scratch area to be used when GDB
7164 calls a function in the target. This is necessary because the
7165 usual method of putting the scratch area on the stack does not work
7166 in systems that have separate instruction and data spaces.
7168 We integrated changes to support the 29k UDI (Universal Debugger
7169 Interface), but discovered at the last minute that we didn't have all
7170 of the appropriate copyright paperwork. We are working with AMD to
7171 resolve this, and hope to have it available soon.
7175 We have sped up the remote serial line protocol, especially for targets
7176 with lots of registers. It now supports a new `expedited status' ('T')
7177 message which can be used in place of the existing 'S' status message.
7178 This allows the remote stub to send only the registers that GDB
7179 needs to make a quick decision about single-stepping or conditional
7180 breakpoints, eliminating the need to fetch the entire register set for
7181 each instruction being stepped through.
7183 The GDB remote serial protocol now implements a write-through cache for
7184 registers, only re-reading the registers if the target has run.
7186 There is also a new remote serial stub for SPARC processors. You can
7187 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7188 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7189 processor with a serial port.
7193 Configure.in files have become much easier to read and modify. A new
7194 `table driven' format makes it more obvious what configurations are
7195 supported, and what files each one uses.
7199 There is a new opcodes library which will eventually contain all of the
7200 disassembly routines and opcode tables. At present, it only contains
7201 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7202 disassembler (binutils/objdump) to share these routines.
7204 The libiberty library is now copylefted under the GNU Library General
7205 Public License. This allows more liberal use, and was done so libg++
7206 can use it. This makes no difference to GDB, since the Library License
7207 grants all the rights from the General Public License.
7211 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7212 reference to the stabs symbol info used by the debugger. It is (as far
7213 as we know) the only published document on this fascinating topic. We
7214 encourage you to read it, compare it to the stabs information on your
7215 system, and send improvements on the document in general (to
7216 bug-gdb@prep.ai.mit.edu).
7218 And, of course, many bugs have been fixed.
7221 *** Changes in GDB-4.6:
7223 * Better support for C++ function names
7225 GDB now accepts as input the "demangled form" of C++ overloaded function
7226 names and member function names, and can do command completion on such names
7227 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7228 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7229 Make use of command completion, it is your friend.
7231 GDB also now accepts a variety of C++ mangled symbol formats. They are
7232 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7233 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7234 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7235 for the list of formats.
7237 * G++ symbol mangling problem
7239 Recent versions of gcc have a bug in how they emit debugging information for
7240 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7241 directory) can be applied to gcc to fix the problem. Alternatively, if you
7242 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7243 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7244 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7247 * New 'maintenance' command
7249 All of the commands related to hacking GDB internals have been moved out of
7250 the main command set, and now live behind the 'maintenance' command. This
7251 can also be abbreviated as 'mt'. The following changes were made:
7253 dump-me -> maintenance dump-me
7254 info all-breakpoints -> maintenance info breakpoints
7255 printmsyms -> maintenance print msyms
7256 printobjfiles -> maintenance print objfiles
7257 printpsyms -> maintenance print psymbols
7258 printsyms -> maintenance print symbols
7260 The following commands are new:
7262 maintenance demangle Call internal GDB demangler routine to
7263 demangle a C++ link name and prints the result.
7264 maintenance print type Print a type chain for a given symbol
7266 * Change to .gdbinit file processing
7268 We now read the $HOME/.gdbinit file before processing the argv arguments
7269 (e.g. reading symbol files or core files). This allows global parameters to
7270 be set, which will apply during the symbol reading. The ./.gdbinit is still
7271 read after argv processing.
7273 * New hosts supported
7275 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7277 GNU/Linux support i386-unknown-linux or linux
7279 We are also including code to support the HP/PA running BSD and HPUX. This
7280 is almost guaranteed not to work, as we didn't have time to test or build it
7281 for this release. We are including it so that the more adventurous (or
7282 masochistic) of you can play with it. We also had major problems with the
7283 fact that the compiler that we got from HP doesn't support the -g option.
7286 * New targets supported
7288 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7290 * More smarts about finding #include files
7292 GDB now remembers the compilation directory for all include files, and for
7293 all files from which C is generated (like yacc and lex sources). This
7294 greatly improves GDB's ability to find yacc/lex sources, and include files,
7295 especially if you are debugging your program from a directory different from
7296 the one that contains your sources.
7298 We also fixed a bug which caused difficulty with listing and setting
7299 breakpoints in include files which contain C code. (In the past, you had to
7300 try twice in order to list an include file that you hadn't looked at before.)
7302 * Interesting infernals change
7304 GDB now deals with arbitrary numbers of sections, where the symbols for each
7305 section must be relocated relative to that section's landing place in the
7306 target's address space. This work was needed to support ELF with embedded
7307 stabs used by Solaris-2.0.
7309 * Bug fixes (of course!)
7311 There have been loads of fixes for the following things:
7312 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7313 i960, stabs, DOS(GO32), procfs, etc...
7315 See the ChangeLog for details.
7317 *** Changes in GDB-4.5:
7319 * New machines supported (host and target)
7321 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7323 SGI Irix-4.x mips-sgi-irix4 or iris4
7325 * New malloc package
7327 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7328 Mmalloc is capable of handling mutiple heaps of memory. It is also
7329 capable of saving a heap to a file, and then mapping it back in later.
7330 This can be used to greatly speedup the startup of GDB by using a
7331 pre-parsed symbol table which lives in a mmalloc managed heap. For
7332 more details, please read mmalloc/mmalloc.texi.
7336 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7337 'help info proc' for details.
7339 * MIPS ecoff symbol table format
7341 The code that reads MIPS symbol table format is now supported on all hosts.
7342 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7345 * File name changes for MS-DOS
7347 Many files in the config directories have been renamed to make it easier to
7348 support GDB on MS-DOSe systems (which have very restrictive file name
7349 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7350 environment) is close to working but has some remaining problems. Note
7351 that debugging of DOS programs is not supported, due to limitations
7352 in the ``operating system'', but it can be used to host cross-debugging.
7354 * Cross byte order fixes
7356 Many fixes have been made to support cross debugging of Sparc and MIPS
7357 targets from hosts whose byte order differs.
7359 * New -mapped and -readnow options
7361 If memory-mapped files are available on your system through the 'mmap'
7362 system call, you can use the -mapped option on the `file' or
7363 `symbol-file' commands to cause GDB to write the symbols from your
7364 program into a reusable file. If the program you are debugging is
7365 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7366 Future GDB debugging sessions will notice the presence of this file,
7367 and will quickly map in symbol information from it, rather than reading
7368 the symbol table from the executable program. Using the '-mapped'
7369 option in a GDB `file' or `symbol-file' command has the same effect as
7370 starting GDB with the '-mapped' command-line option.
7372 You can cause GDB to read the entire symbol table immediately by using
7373 the '-readnow' option with any of the commands that load symbol table
7374 information (or on the GDB command line). This makes the command
7375 slower, but makes future operations faster.
7377 The -mapped and -readnow options are typically combined in order to
7378 build a `fred.syms' file that contains complete symbol information.
7379 A simple GDB invocation to do nothing but build a `.syms' file for future
7382 gdb -batch -nx -mapped -readnow programname
7384 The `.syms' file is specific to the host machine on which GDB is run.
7385 It holds an exact image of GDB's internal symbol table. It cannot be
7386 shared across multiple host platforms.
7388 * longjmp() handling
7390 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7391 siglongjmp() without losing control. This feature has not yet been ported to
7392 all systems. It currently works on many 386 platforms, all MIPS-based
7393 platforms (SGI, DECstation, etc), and Sun3/4.
7397 Preliminary work has been put in to support the new Solaris OS from Sun. At
7398 this time, it can control and debug processes, but it is not capable of
7403 As always, many many bug fixes. The major areas were with g++, and mipsread.
7404 People using the MIPS-based platforms should experience fewer mysterious
7405 crashes and trashed symbol tables.
7407 *** Changes in GDB-4.4:
7409 * New machines supported (host and target)
7411 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7413 BSD Reno on Vax vax-dec-bsd
7414 Ultrix on Vax vax-dec-ultrix
7416 * New machines supported (target)
7418 AMD 29000 embedded, using EBMON a29k-none-none
7422 GDB continues to improve its handling of C++. `References' work better.
7423 The demangler has also been improved, and now deals with symbols mangled as
7424 per the Annotated C++ Reference Guide.
7426 GDB also now handles `stabs' symbol information embedded in MIPS
7427 `ecoff' symbol tables. Since the ecoff format was not easily
7428 extensible to handle new languages such as C++, this appeared to be a
7429 good way to put C++ debugging info into MIPS binaries. This option
7430 will be supported in the GNU C compiler, version 2, when it is
7433 * New features for SVR4
7435 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7436 shared libraries. Debugging dynamically linked programs should present
7437 only minor differences from debugging statically linked programs.
7439 The `info proc' command will print out information about any process
7440 on an SVR4 system (including the one you are debugging). At the moment,
7441 it prints the address mappings of the process.
7443 If you bring up GDB on another SVR4 system, please send mail to
7444 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7446 * Better dynamic linking support in SunOS
7448 Reading symbols from shared libraries which contain debugging symbols
7449 now works properly. However, there remain issues such as automatic
7450 skipping of `transfer vector' code during function calls, which
7451 make it harder to debug code in a shared library, than to debug the
7452 same code linked statically.
7456 GDB is now using the latest `getopt' routines from the FSF. This
7457 version accepts the -- prefix for options with long names. GDB will
7458 continue to accept the old forms (-option and +option) as well.
7459 Various single letter abbreviations for options have been explicity
7460 added to the option table so that they won't get overshadowed in the
7461 future by other options that begin with the same letter.
7465 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7466 Many assorted bugs have been handled. Many more remain to be handled.
7467 See the various ChangeLog files (primarily in gdb and bfd) for details.
7470 *** Changes in GDB-4.3:
7472 * New machines supported (host and target)
7474 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7475 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7476 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7478 * Almost SCO Unix support
7480 We had hoped to support:
7481 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7482 (except for core file support), but we discovered very late in the release
7483 that it has problems with process groups that render gdb unusable. Sorry
7484 about that. I encourage people to fix it and post the fixes.
7486 * Preliminary ELF and DWARF support
7488 GDB can read ELF object files on System V Release 4, and can handle
7489 debugging records for C, in DWARF format, in ELF files. This support
7490 is preliminary. If you bring up GDB on another SVR4 system, please
7491 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7496 GDB now uses the latest `readline' library. One user-visible change
7497 is that two tabs will list possible command completions, which previously
7498 required typing M-? (meta-question mark, or ESC ?).
7502 The `stepi' bug that many of you noticed has been squashed.
7503 Many bugs in C++ have been handled. Many more remain to be handled.
7504 See the various ChangeLog files (primarily in gdb and bfd) for details.
7506 * State of the MIPS world (in case you wondered):
7508 GDB can understand the symbol tables emitted by the compilers
7509 supplied by most vendors of MIPS-based machines, including DEC. These
7510 symbol tables are in a format that essentially nobody else uses.
7512 Some versions of gcc come with an assembler post-processor called
7513 mips-tfile. This program is required if you want to do source-level
7514 debugging of gcc-compiled programs. I believe FSF does not ship
7515 mips-tfile with gcc version 1, but it will eventually come with gcc
7518 Debugging of g++ output remains a problem. g++ version 1.xx does not
7519 really support it at all. (If you're lucky, you should be able to get
7520 line numbers and stack traces to work, but no parameters or local
7521 variables.) With some work it should be possible to improve the
7524 When gcc version 2 is released, you will have somewhat better luck.
7525 However, even then you will get confusing results for inheritance and
7528 We will eventually provide full debugging of g++ output on
7529 DECstations. This will probably involve some kind of stabs-in-ecoff
7530 encapulation, but the details have not been worked out yet.
7533 *** Changes in GDB-4.2:
7535 * Improved configuration
7537 Only one copy of `configure' exists now, and it is not self-modifying.
7538 Porting BFD is simpler.
7542 The `step' and `next' commands now only stop at the first instruction
7543 of a source line. This prevents the multiple stops that used to occur
7544 in switch statements, for-loops, etc. `Step' continues to stop if a
7545 function that has debugging information is called within the line.
7549 Lots of small bugs fixed. More remain.
7551 * New host supported (not target)
7553 Intel 386 PC clone running Mach i386-none-mach
7556 *** Changes in GDB-4.1:
7558 * Multiple source language support
7560 GDB now has internal scaffolding to handle several source languages.
7561 It determines the type of each source file from its filename extension,
7562 and will switch expression parsing and number formatting to match the
7563 language of the function in the currently selected stack frame.
7564 You can also specifically set the language to be used, with
7565 `set language c' or `set language modula-2'.
7569 GDB now has preliminary support for the GNU Modula-2 compiler,
7570 currently under development at the State University of New York at
7571 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7572 continue through the fall of 1991 and into 1992.
7574 Other Modula-2 compilers are currently not supported, and attempting to
7575 debug programs compiled with them will likely result in an error as the
7576 symbol table is read. Feel free to work on it, though!
7578 There are hooks in GDB for strict type checking and range checking,
7579 in the `Modula-2 philosophy', but they do not currently work.
7583 GDB can now write to executable and core files (e.g. patch
7584 a variable's value). You must turn this switch on, specify
7585 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7586 by assigning a new value to a variable. Modifications take
7589 * Automatic SunOS shared library reading
7591 When you run your program, GDB automatically determines where its
7592 shared libraries (if any) have been loaded, and reads their symbols.
7593 The `share' command is no longer needed. This also works when
7594 examining core files.
7598 You can specify the number of lines that the `list' command shows.
7601 * New machines supported (host and target)
7603 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7604 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7605 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7607 * New hosts supported (not targets)
7609 IBM RT/PC: romp-ibm-aix or rtpc
7611 * New targets supported (not hosts)
7613 AMD 29000 embedded with COFF a29k-none-coff
7614 AMD 29000 embedded with a.out a29k-none-aout
7615 Ultracomputer remote kernel debug a29k-nyu-kern
7617 * New remote interfaces
7623 *** Changes in GDB-4.0:
7627 Wide output is wrapped at good places to make the output more readable.
7629 Gdb now supports cross-debugging from a host machine of one type to a
7630 target machine of another type. Communication with the target system
7631 is over serial lines. The ``target'' command handles connecting to the
7632 remote system; the ``load'' command will download a program into the
7633 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7634 also supports debugging of realtime processes running under VxWorks,
7635 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7636 stub on the target system.
7638 New CPUs supported include the AMD 29000 and Intel 960.
7640 GDB now reads object files and symbol tables via a ``binary file''
7641 library, which allows a single copy of GDB to debug programs of multiple
7642 object file types such as a.out and coff.
7644 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7645 refcard.dvi and refcard.ps are available to format it).
7648 * Control-Variable user interface simplified
7650 All variables that control the operation of the debugger can be set
7651 by the ``set'' command, and displayed by the ``show'' command.
7653 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7654 ``Show prompt'' produces the response:
7655 Gdb's prompt is new-gdb=>.
7657 What follows are the NEW set commands. The command ``help set'' will
7658 print a complete list of old and new set commands. ``help set FOO''
7659 will give a longer description of the variable FOO. ``show'' will show
7660 all of the variable descriptions and their current settings.
7662 confirm on/off: Enables warning questions for operations that are
7663 hard to recover from, e.g. rerunning the program while
7664 it is already running. Default is ON.
7666 editing on/off: Enables EMACS style command line editing
7667 of input. Previous lines can be recalled with
7668 control-P, the current line can be edited with control-B,
7669 you can search for commands with control-R, etc.
7672 history filename NAME: NAME is where the gdb command history
7673 will be stored. The default is .gdb_history,
7674 or the value of the environment variable
7677 history size N: The size, in commands, of the command history. The
7678 default is 256, or the value of the environment variable
7681 history save on/off: If this value is set to ON, the history file will
7682 be saved after exiting gdb. If set to OFF, the
7683 file will not be saved. The default is OFF.
7685 history expansion on/off: If this value is set to ON, then csh-like
7686 history expansion will be performed on
7687 command line input. The default is OFF.
7689 radix N: Sets the default radix for input and output. It can be set
7690 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7691 in the current radix, so "set radix 10" is always a no-op.
7693 height N: This integer value is the number of lines on a page. Default
7694 is 24, the current `stty rows'' setting, or the ``li#''
7695 setting from the termcap entry matching the environment
7698 width N: This integer value is the number of characters on a line.
7699 Default is 80, the current `stty cols'' setting, or the ``co#''
7700 setting from the termcap entry matching the environment
7703 Note: ``set screensize'' is obsolete. Use ``set height'' and
7704 ``set width'' instead.
7706 print address on/off: Print memory addresses in various command displays,
7707 such as stack traces and structure values. Gdb looks
7708 more ``symbolic'' if you turn this off; it looks more
7709 ``machine level'' with it on. Default is ON.
7711 print array on/off: Prettyprint arrays. New convenient format! Default
7714 print demangle on/off: Print C++ symbols in "source" form if on,
7717 print asm-demangle on/off: Same, for assembler level printouts
7720 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7723 * Support for Epoch Environment.
7725 The epoch environment is a version of Emacs v18 with windowing. One
7726 new command, ``inspect'', is identical to ``print'', except that if you
7727 are running in the epoch environment, the value is printed in its own
7731 * Support for Shared Libraries
7733 GDB can now debug programs and core files that use SunOS shared libraries.
7734 Symbols from a shared library cannot be referenced
7735 before the shared library has been linked with the program (this
7736 happens after you type ``run'' and before the function main() is entered).
7737 At any time after this linking (including when examining core files
7738 from dynamically linked programs), gdb reads the symbols from each
7739 shared library when you type the ``sharedlibrary'' command.
7740 It can be abbreviated ``share''.
7742 sharedlibrary REGEXP: Load shared object library symbols for files
7743 matching a unix regular expression. No argument
7744 indicates to load symbols for all shared libraries.
7746 info sharedlibrary: Status of loaded shared libraries.
7751 A watchpoint stops execution of a program whenever the value of an
7752 expression changes. Checking for this slows down execution
7753 tremendously whenever you are in the scope of the expression, but is
7754 quite useful for catching tough ``bit-spreader'' or pointer misuse
7755 problems. Some machines such as the 386 have hardware for doing this
7756 more quickly, and future versions of gdb will use this hardware.
7758 watch EXP: Set a watchpoint (breakpoint) for an expression.
7760 info watchpoints: Information about your watchpoints.
7762 delete N: Deletes watchpoint number N (same as breakpoints).
7763 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7764 enable N: Re-enables watchpoint number N (same as breakpoints).
7767 * C++ multiple inheritance
7769 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7772 * C++ exception handling
7774 Gdb now supports limited C++ exception handling. Besides the existing
7775 ability to breakpoint on an exception handler, gdb can breakpoint on
7776 the raising of an exception (before the stack is peeled back to the
7779 catch FOO: If there is a FOO exception handler in the dynamic scope,
7780 set a breakpoint to catch exceptions which may be raised there.
7781 Multiple exceptions (``catch foo bar baz'') may be caught.
7783 info catch: Lists all exceptions which may be caught in the
7784 current stack frame.
7787 * Minor command changes
7789 The command ``call func (arg, arg, ...)'' now acts like the print
7790 command, except it does not print or save a value if the function's result
7791 is void. This is similar to dbx usage.
7793 The ``up'' and ``down'' commands now always print the frame they end up
7794 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7795 frames without printing.
7797 * New directory command
7799 'dir' now adds directories to the FRONT of the source search path.
7800 The path starts off empty. Source files that contain debug information
7801 about the directory in which they were compiled can be found even
7802 with an empty path; Sun CC and GCC include this information. If GDB can't
7803 find your source file in the current directory, type "dir .".
7805 * Configuring GDB for compilation
7807 For normal use, type ``./configure host''. See README or gdb.texinfo
7810 GDB now handles cross debugging. If you are remotely debugging between
7811 two different machines, type ``./configure host -target=targ''.
7812 Host is the machine where GDB will run; targ is the machine
7813 where the program that you are debugging will run.