1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.3
6 * 'thread-exited' event is now available in the annotations interface.
8 * New built-in convenience variables $_gdb_major and $_gdb_minor
9 provide the GDB version. They are handy for conditionally using
10 features available only in or since specific GDB versions, in
11 scripts that should work error-free with many different versions,
12 such as in system-wide init files.
14 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
15 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
16 of the GDB settings and the GDB maintenance settings. They are handy
17 for changing the logic of user defined commands depending on the
20 * GDB now supports Thread Local Storage (TLS) variables on several
21 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
22 architectures require kernel changes. TLS is not yet supported for
23 amd64 and i386 process core dumps.
25 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
26 addresses that required unmasking are shown in the backtrace with the
29 * Two new convenience functions $_cimag and $_creal that extract the
30 imaginary and real parts respectively from complex numbers.
32 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
33 provide the exitcode or exit status of the shell commands launched by
34 GDB commands such as "shell", "pipe" and "make".
36 * The command define-prefix can now define user defined prefix commands.
37 User defined commands can now be defined using these user defined prefix
40 * Command names can now use the . character.
42 * The RX port now supports XML target descriptions.
44 * GDB now shows the Ada task names at more places, e.g. in task switching
47 * GDB can now be compiled with Python 3 on Windows.
49 * New convenience variable $_ada_exception holds the address of the
50 Ada exception being thrown. This is set by Ada-related catchpoints.
52 * GDB can now place breakpoints on nested functions and subroutines in
53 Fortran code. The '::' operator can be used between parent and
54 child scopes when placing breakpoints, for example:
56 (gdb) break outer_function::inner_function
58 The 'outer_function::' prefix is only needed if 'inner_function' is
59 not visible in the current scope.
61 * In addition to the system-wide gdbinit file, if configured with
62 --with-system-gdbinit-dir, GDB will now also load files in that directory
63 as system gdbinit files, unless the -nx or -n flag is provided. Files
64 with extensions .gdb, .py and .scm are supported as long as GDB was
65 compiled with support for that language.
67 * GDB now supports multithreaded symbol loading for higher performance.
68 This feature is still in testing, so it is disabled by default. You
69 can turn it on using 'maint set worker-threads unlimited'.
73 ** The gdb.Value type has a new method 'format_string' which returns a
74 string representing the value. The formatting is controlled by the
75 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
76 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
77 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
79 ** gdb.Type has a new property 'objfile' which returns the objfile the
82 ** The frame information printed by the python frame filtering code
83 is now consistent with what the 'backtrace' command prints when
84 there are no filters, or when the 'backtrace' '-no-filters' option
87 ** The new function gdb.lookup_static_symbol can be used to look up
88 symbols with static linkage.
90 ** The new function gdb.lookup_static_symbols can be used to look up
91 all static symbols with static linkage.
93 ** gdb.Objfile has new methods 'lookup_global_symbol' and
94 'lookup_static_symbol' to lookup a symbol from this objfile only.
96 ** gdb.Block now supports the dictionary syntax for accessing symbols in
97 this block (e.g. block['local_variable']).
101 | [COMMAND] | SHELL_COMMAND
102 | -d DELIM COMMAND DELIM SHELL_COMMAND
103 pipe [COMMAND] | SHELL_COMMAND
104 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
105 Executes COMMAND and sends its output to SHELL_COMMAND.
106 With no COMMAND, repeat the last executed command
107 and send its output to SHELL_COMMAND.
109 define-prefix COMMAND
110 Define or mark a command as a user-defined prefix command.
112 with SETTING [VALUE] [-- COMMAND]
113 w SETTING [VALUE] [-- COMMAND]
114 Temporarily set SETTING, run COMMAND, and restore SETTING.
115 Usage: with SETTING -- COMMAND
116 With no COMMAND, repeats the last executed command.
117 SETTING is any GDB setting you can change with the "set"
118 subcommands. For example, 'with language c -- print someobj'
119 temporarily switches to the C language in order to print someobj.
120 Settings can be combined: 'w lang c -- w print elements unlimited --
121 usercmd' switches to the C language and runs usercmd with no limit
122 of array elements to print.
124 maint with SETTING [VALUE] [-- COMMAND]
125 Like "with", but works with "maintenance set" settings.
127 set may-call-functions [on|off]
128 show may-call-functions
129 This controls whether GDB will attempt to call functions in
130 the program, such as with expressions in the print command. It
131 defaults to on. Calling functions in the program being debugged
132 can have undesired side effects. It is now possible to forbid
133 such function calls. If function calls are forbidden, GDB will throw
134 an error when a command (such as print expression) calls a function
137 set print finish [on|off]
139 This controls whether the `finish' command will display the value
140 that is returned by the current function. When `off', the value is
141 still entered into the value history, but it is not printed. The
146 Allows deeply nested structures to be simplified when printing by
147 replacing deeply nested parts (beyond the max-depth) with ellipses.
148 The default max-depth is 20, but this can be set to unlimited to get
149 the old behavior back.
151 set logging debugredirect [on|off]
152 By default, GDB debug output will go to both the terminal and the logfile.
153 Set if you want debug output to go only to the log file.
155 set style title foreground COLOR
156 set style title background COLOR
157 set style title intensity VALUE
158 Control the styling of titles.
160 set style highlight foreground COLOR
161 set style highlight background COLOR
162 set style highlight intensity VALUE
163 Control the styling of highlightings.
165 maint set worker-threads
166 maint show worker-threads
167 Control the number of worker threads that can be used by GDB. The
168 default is 0. "unlimited" lets GDB choose a number that is
169 reasonable. Currently worker threads are only used when demangling
170 the names of linker symbols.
172 set style tui-border foreground COLOR
173 set style tui-border background COLOR
174 Control the styling of TUI borders.
176 set style tui-active-border foreground COLOR
177 set style tui-active-border background COLOR
178 Control the styling of the active TUI border.
180 maint set test-settings KIND
181 maint show test-settings KIND
182 A set of commands used by the testsuite for exercising the settings
185 maint set tui-resize-message [on|off]
186 maint show tui-resize-message
187 Control whether GDB prints a message each time the terminal is
188 resized when in TUI mode. This is primarily useful for testing the
191 set print frame-info [short-location|location|location-and-address
192 |source-and-location|source-line|auto]
193 show print frame-info
194 This controls what frame information is printed by the commands printing
195 a frame. This setting will e.g. influence the behaviour of 'backtrace',
196 'frame', 'stepi'. The python frame filtering also respect this setting.
197 The 'backtrace' '-frame-info' option can override this global setting.
199 set tui compact-source
200 show tui compact-source
202 Enable the "compact" display mode for the TUI source window. The
203 compact display uses only as much space as is needed for the line
204 numbers in the current file, and only a single space to separate the
205 line numbers from the source.
207 info modules [-q] [REGEXP]
208 Return a list of Fortran modules matching REGEXP, or all modules if
211 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
212 Return a list of functions within all modules, grouped by module.
213 The list of functions can be restricted with the optional regular
214 expressions. MODULE_REGEXP matches against the module name,
215 TYPE_REGEXP matches against the function type signature, and REGEXP
216 matches against the function name.
218 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
219 Return a list of variables within all modules, grouped by module.
220 The list of variables can be restricted with the optional regular
221 expressions. MODULE_REGEXP matches against the module name,
222 TYPE_REGEXP matches against the variable type, and REGEXP matches
223 against the variable name.
225 set debug remote-packet-max-chars
226 show debug remote-packet-max-chars
227 Controls the number of characters to output in a remote packet when using
229 The default is 512 bytes.
234 The "help" command uses the title style to enhance the
235 readibility of its output by styling the classes and
239 Similarly to "help", the "apropos" command also uses the
240 title style for the command names. "apropos" accepts now
241 a flag "-v" (verbose) to show the full documentation
242 of matching commands and to use the highlight style to mark
243 the documentation parts matching REGEXP.
247 The GDB printf and eval commands can now print C-style and Ada-style
248 string convenience variables without calling functions in the program.
249 This allows to do formatted printing of strings without having
250 a running inferior, or when debugging a core dump.
252 info sources [-dirname | -basename] [--] [REGEXP]
253 This command has now optional arguments to only print the files
254 whose names match REGEXP. The arguments -dirname and -basename
255 allow to restrict matching respectively to the dirname and basename
259 The "show style" and its subcommands are now styling
260 a style name in their output using its own style, to help
261 the user visualize the different styles.
263 set print frame-arguments
264 The new value 'presence' indicates to only indicate the presence of
265 arguments using ..., instead of printing argument names and values.
267 set print raw-frame-arguments
268 show print raw-frame-arguments
270 These commands replace the similarly-named "set/show print raw
271 frame-arguments" commands (now with a dash instead of a space). The
272 old commands are now deprecated and may be removed in a future
275 maint test-options require-delimiter
276 maint test-options unknown-is-error
277 maint test-options unknown-is-operand
278 maint show test-options-completion-result
279 Commands used by the testsuite to validate the command options
282 focus, winheight, +, -, >, <
283 These commands are now case-sensitive.
285 * New command options, command completion
287 GDB now has a standard infrastructure to support dash-style command
288 options ('-OPT'). One benefit is that commands that use it can
289 easily support completion of command line arguments. Try "CMD
290 -[TAB]" or "help CMD" to find options supported by a command. Over
291 time, we intend to migrate most commands to this infrastructure. A
292 number of commands got support for new command options in this
295 ** The "print" and "compile print" commands now support a number of
296 options that allow overriding relevant global print settings as
297 set by "set print" subcommands:
301 -array-indexes [on|off]
302 -elements NUMBER|unlimited
306 -repeats NUMBER|unlimited
307 -static-members [on|off]
312 Note that because the "print"/"compile print" commands accept
313 arbitrary expressions which may look like options (including
314 abbreviations), if you specify any command option, then you must
315 use a double dash ("--") to mark the end of argument processing.
317 ** The "backtrace" command now supports a number of options that
318 allow overriding relevant global print settings as set by "set
319 backtrace" and "set print" subcommands:
321 -entry-values no|only|preferred|if-needed|both|compact|default
322 -frame-arguments all|scalars|none
323 -raw-frame-arguments [on|off]
324 -frame-info auto|source-line|location|source-and-location
325 |location-and-address|short-location
329 In addition, the full/no-filters/hide qualifiers are now also
330 exposed as command options too:
336 ** The "frame apply", "tfaas" and "faas" commands similarly now
337 support the following options:
342 ** The new "info sources" options -dirname and -basename options
343 are using the standard '-OPT' infrastructure.
345 All options above can also be abbreviated. The argument of boolean
346 (on/off) options can be 0/1 too, and also the argument is assumed
347 "on" if omitted. This allows writing compact command invocations,
350 (gdb) p -r -p -o 0 -- *myptr
352 The above is equivalent to:
354 (gdb) print -raw -pretty -object off -- *myptr
356 ** The "info types" command now supports the '-q' flag to disable
357 printing of some header information in a similar fashion to "info
358 variables" and "info functions".
360 ** The "info variables", "info functions", and "whereis" commands
361 now take a '-n' flag that excludes non-debug symbols (symbols
362 from the symbol table, not from the debug info such as DWARF)
365 * Completion improvements
367 ** GDB can now complete the options of the "thread apply all" and
368 "taas" commands, and their "-ascending" option can now be
371 ** GDB can now complete the options of the "info threads", "info
372 functions", "info variables", "info locals", and "info args"
375 ** GDB can now complete the options of the "compile file" and
376 "compile code" commands. The "compile file" command now
377 completes on filenames.
379 ** GDB can now complete the backtrace command's
380 "full/no-filters/hide" qualifiers.
382 * In settings, you can now abbreviate "unlimited".
384 E.g., "set print elements u" is now equivalent to "set print
390 This lists all the possible completions for the rest of the line, if it
391 were to be given as a command itself. This is intended for use by MI
392 frontends in cases when separate CLI and MI channels cannot be used.
394 -catch-throw, -catch-rethrow, and -catch-catch
395 These can be used to catch C++ exceptions in a similar fashion to
396 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
398 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
399 These commands are the MI equivalent of the CLI commands 'info
400 functions', 'info types', and 'info variables' respectively.
402 -symbol-info-modules, this is the MI equivalent of the CLI 'info
405 -symbol-info-module-functions and -symbol-info-module-variables.
406 These commands are the MI equivalent of the CLI commands 'info
407 module functions' and 'info module variables'.
411 ** The default version of the MI interpreter is now 3 (-i=mi3).
413 ** The output of information about multi-location breakpoints (which is
414 syntactically incorrect in MI 2) has changed in MI 3. This affects
415 the following commands and events:
419 - =breakpoint-created
420 - =breakpoint-modified
422 The -fix-multi-location-breakpoint-output command can be used to enable
423 this behavior with previous MI versions.
425 ** Backtraces and frames include a new optional field addr_flags which is
426 given after the addr field. On AArch64 this contains PAC if the address
427 has been masked in the frame. On all other targets the field is not
432 The testsuite now creates the files gdb.cmd (containing the arguments
433 used to launch GDB) and gdb.in (containing all the commands sent to
434 GDB) in the output directory for each test script. Multiple invocations
435 are appended with .1, .2, .3 etc.
437 * Building GDB and GDBserver now requires GNU make >= 3.82.
439 Using another implementation of the make program or an earlier version of
440 GNU make to build GDB or GDBserver is not supported.
442 * Building GDB now requires GNU readline >= 7.0.
444 GDB now bundles GNU readline 8.0, but if you choose to use
445 --with-system-readline, only readline >= 7.0 can be used.
447 * The TUI SingleKey keymap is now named "SingleKey". This can be used
448 from .inputrc to bind keys in this keymap. This feature is only
449 available when gdb is built against GNU readline 8.0 or later.
451 * Removed targets and native configurations
453 GDB no longer supports debugging the Cell Broadband Engine. This includes
454 both debugging standalone Cell/B.E. SPU applications and integrated debugging
455 of Cell/B.E. applications that use both the PPU and SPU architectures.
461 * Removed targets and native configurations
463 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
466 *** Changes in GDB 8.3
468 * GDB and GDBserver now support access to additional registers on
469 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
472 * GDB now has experimental support for the compilation and injection of
473 C++ source code into the inferior. This beta release does not include
474 support for several language features, such as templates, constructors,
477 This feature requires GCC 7.1 or higher built with libcp1.so
480 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
481 can be passed using the '[ADDRESS]:PORT' notation, or the regular
482 'ADDRESS:PORT' method.
484 * DWARF index cache: GDB can now automatically save indices of DWARF
485 symbols on disk to speed up further loading of the same binaries.
487 * Ada task switching is now supported on aarch64-elf targets when
488 debugging a program using the Ravenscar Profile. For more information,
489 see the "Tasking Support when using the Ravenscar Profile" section
490 in the GDB user manual.
492 * GDB in batch mode now exits with status 1 if the last command to be
495 * The RISC-V target now supports target descriptions.
497 * System call catchpoints now support system call aliases on FreeBSD.
498 When the ABI of a system call changes in FreeBSD, this is
499 implemented by leaving a compatibility system call using the old ABI
500 at the existing number and allocating a new system call number for
501 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
502 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
503 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
504 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
505 so that a system call catchpoint for the 'kevent' system call will
506 catch invocations of both the 'kevent' and 'freebsd11_kevent'
507 binaries. This ensures that 'kevent' system calls are caught for
508 binaries using either the old or new ABIs.
510 * Terminal styling is now available for the CLI and the TUI. GNU
511 Source Highlight can additionally be used to provide styling of
512 source code snippets. See the "set style" commands, below, for more
515 * Removed support for old demangling styles arm, edg, gnu, hp and
520 set debug compile-cplus-types
521 show debug compile-cplus-types
522 Control the display of debug output about type conversion in the
523 C++ compile feature. Commands have no effect while compiliong
528 Control whether debug output about files/functions skipping is
531 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
532 Apply a command to some frames.
533 FLAG arguments allow to control what output to produce and how to handle
534 errors raised when applying COMMAND to a frame.
537 Apply a command to all threads (ignoring errors and empty output).
538 Shortcut for 'thread apply all -s COMMAND'.
541 Apply a command to all frames (ignoring errors and empty output).
542 Shortcut for 'frame apply all -s COMMAND'.
545 Apply a command to all frames of all threads (ignoring errors and empty
547 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
549 maint set dwarf unwinders (on|off)
550 maint show dwarf unwinders
551 Control whether DWARF unwinders can be used.
554 Display a list of open files for a process.
558 Changes to the "frame", "select-frame", and "info frame" CLI commands.
559 These commands all now take a frame specification which
560 is either a frame level, or one of the keywords 'level', 'address',
561 'function', or 'view' followed by a parameter. Selecting a frame by
562 address, or viewing a frame outside the current backtrace now
563 requires the use of a keyword. Selecting a frame by level is
564 unchanged. The MI comment "-stack-select-frame" is unchanged.
566 target remote FILENAME
567 target extended-remote FILENAME
568 If FILENAME is a Unix domain socket, GDB will attempt to connect
569 to this socket instead of opening FILENAME as a character device.
571 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
572 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
573 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
574 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
575 These commands can now print only the searched entities
576 matching the provided regexp(s), giving a condition
577 on the entity names or entity types. The flag -q disables
578 printing headers or informations messages.
584 These commands now determine the syntax for the shown entities
585 according to the language chosen by `set language'. In particular,
586 `set language auto' means to automatically choose the language of
589 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
590 The 'thread apply' command accepts new FLAG arguments.
591 FLAG arguments allow to control what output to produce and how to handle
592 errors raised when applying COMMAND to a thread.
594 set tui tab-width NCHARS
595 show tui tab-width NCHARS
596 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
598 set style enabled [on|off]
600 Enable or disable terminal styling. Styling is enabled by default
601 on most hosts, but disabled by default when in batch mode.
603 set style sources [on|off]
605 Enable or disable source code styling. Source code styling is
606 enabled by default, but only takes effect if styling in general is
607 enabled, and if GDB was linked with GNU Source Highlight.
609 set style filename foreground COLOR
610 set style filename background COLOR
611 set style filename intensity VALUE
612 Control the styling of file names.
614 set style function foreground COLOR
615 set style function background COLOR
616 set style function intensity VALUE
617 Control the styling of function names.
619 set style variable foreground COLOR
620 set style variable background COLOR
621 set style variable intensity VALUE
622 Control the styling of variable names.
624 set style address foreground COLOR
625 set style address background COLOR
626 set style address intensity VALUE
627 Control the styling of addresses.
631 ** The '-data-disassemble' MI command now accepts an '-a' option to
632 disassemble the whole function surrounding the given program
633 counter value or function name. Support for this feature can be
634 verified by using the "-list-features" command, which should
635 contain "data-disassemble-a-option".
637 ** Command responses and notifications that include a frame now include
638 the frame's architecture in a new "arch" attribute.
640 * New native configurations
642 GNU/Linux/RISC-V riscv*-*-linux*
643 FreeBSD/riscv riscv*-*-freebsd*
647 GNU/Linux/RISC-V riscv*-*-linux*
649 CSKY GNU/LINUX csky*-*-linux
650 FreeBSD/riscv riscv*-*-freebsd*
652 GNU/Linux/OpenRISC or1k*-*-linux*
656 GDB no longer supports native debugging on versions of MS-Windows
661 ** GDB no longer supports Python versions less than 2.6.
663 ** The gdb.Inferior type has a new 'progspace' property, which is the program
664 space associated to that inferior.
666 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
667 of objfiles associated to that program space.
669 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
670 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
673 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
674 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
675 correct and did not work properly.
677 ** The gdb.Value type has a new constructor, which is used to construct a
678 gdb.Value from a Python buffer object and a gdb.Type.
684 Enable or disable the undefined behavior sanitizer. This is
685 disabled by default, but passing --enable-ubsan=yes or
686 --enable-ubsan=auto to configure will enable it. Enabling this can
687 cause a performance penalty. The undefined behavior sanitizer was
688 first introduced in GCC 4.9.
690 *** Changes in GDB 8.2
692 * The 'set disassembler-options' command now supports specifying options
695 * The 'symbol-file' command now accepts an '-o' option to add a relative
696 offset to all sections.
698 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
699 a relative offset to all sections, but it allows to override the load
700 address of individual sections using '-s'.
702 * The 'add-symbol-file' command no longer requires the second argument
703 (address of the text section).
705 * The endianness used with the 'set endian auto' mode in the absence of
706 an executable selected for debugging is now the last endianness chosen
707 either by one of the 'set endian big' and 'set endian little' commands
708 or by inferring from the last executable used, rather than the startup
711 * The pager now allows a "c" response, meaning to disable the pager
712 for the rest of the current command.
714 * The commands 'info variables/functions/types' now show the source line
715 numbers of symbol definitions when available.
717 * 'info proc' now works on running processes on FreeBSD systems and core
718 files created on FreeBSD systems.
720 * C expressions can now use _Alignof, and C++ expressions can now use
723 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
724 the vector length while the process is running.
730 Control display of debugging info regarding the FreeBSD native target.
732 set|show varsize-limit
733 This new setting allows the user to control the maximum size of Ada
734 objects being printed when those objects have a variable type,
735 instead of that maximum size being hardcoded to 65536 bytes.
737 set|show record btrace cpu
738 Controls the processor to be used for enabling errata workarounds for
741 maint check libthread-db
742 Run integrity checks on the current inferior's thread debugging
745 maint set check-libthread-db (on|off)
746 maint show check-libthread-db
747 Control whether to run integrity checks on inferior specific thread
748 debugging libraries as they are loaded. The default is not to
753 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
755 ** The commands attached to a breakpoint can be set by assigning to
756 the breakpoint's "commands" field.
758 ** gdb.execute can now execute multi-line gdb commands.
760 ** The new functions gdb.convenience_variable and
761 gdb.set_convenience_variable can be used to get and set the value
762 of convenience variables.
764 ** A gdb.Parameter will no longer print the "set" help text on an
765 ordinary "set"; instead by default a "set" will be silent unless
766 the get_set_string method returns a non-empty string.
770 RiscV ELF riscv*-*-elf
772 * Removed targets and native configurations
774 m88k running OpenBSD m88*-*-openbsd*
775 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
776 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
777 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
779 * Aarch64/Linux hardware watchpoints improvements
781 Hardware watchpoints on unaligned addresses are now properly
782 supported when running Linux kernel 4.10 or higher: read and access
783 watchpoints are no longer spuriously missed, and all watchpoints
784 lengths between 1 and 8 bytes are supported. On older kernels,
785 watchpoints set on unaligned addresses are no longer missed, with
786 the tradeoff that there is a possibility of false hits being
791 --enable-codesign=CERT
792 This can be used to invoke "codesign -s CERT" after building gdb.
793 This option is useful on macOS, where code signing is required for
794 gdb to work properly.
796 --disable-gdbcli has been removed
797 This is now silently accepted, but does nothing.
799 *** Changes in GDB 8.1
801 * GDB now supports dynamically creating arbitrary register groups specified
802 in XML target descriptions. This allows for finer grain grouping of
803 registers on systems with a large amount of registers.
805 * The 'ptype' command now accepts a '/o' flag, which prints the
806 offsets and sizes of fields in a struct, like the pahole(1) tool.
808 * New "--readnever" command line option instructs GDB to not read each
809 symbol file's symbolic debug information. This makes startup faster
810 but at the expense of not being able to perform symbolic debugging.
811 This option is intended for use cases where symbolic debugging will
812 not be used, e.g., when you only need to dump the debuggee's core.
814 * GDB now uses the GNU MPFR library, if available, to emulate target
815 floating-point arithmetic during expression evaluation when the target
816 uses different floating-point formats than the host. At least version
817 3.1 of GNU MPFR is required.
819 * GDB now supports access to the guarded-storage-control registers and the
820 software-based guarded-storage broadcast control registers on IBM z14.
822 * On Unix systems, GDB now supports transmitting environment variables
823 that are to be set or unset to GDBserver. These variables will
824 affect the environment to be passed to the remote inferior.
826 To inform GDB of environment variables that are to be transmitted to
827 GDBserver, use the "set environment" command. Only user set
828 environment variables are sent to GDBserver.
830 To inform GDB of environment variables that are to be unset before
831 the remote inferior is started by the GDBserver, use the "unset
832 environment" command.
834 * Completion improvements
836 ** GDB can now complete function parameters in linespecs and
837 explicit locations without quoting. When setting breakpoints,
838 quoting around functions names to help with TAB-completion is
839 generally no longer necessary. For example, this now completes
842 (gdb) b function(in[TAB]
843 (gdb) b function(int)
845 Related, GDB is no longer confused with completing functions in
846 C++ anonymous namespaces:
849 (gdb) b (anonymous namespace)::[TAB][TAB]
850 (anonymous namespace)::a_function()
851 (anonymous namespace)::b_function()
853 ** GDB now has much improved linespec and explicit locations TAB
854 completion support, that better understands what you're
855 completing and offers better suggestions. For example, GDB no
856 longer offers data symbols as possible completions when you're
857 setting a breakpoint.
859 ** GDB now TAB-completes label symbol names.
861 ** The "complete" command now mimics TAB completion accurately.
863 * New command line options (gcore)
866 Dump all memory mappings.
868 * Breakpoints on C++ functions are now set on all scopes by default
870 By default, breakpoints on functions/methods are now interpreted as
871 specifying all functions with the given name ignoring missing
872 leading scopes (namespaces and classes).
874 For example, assuming a C++ program with symbols named:
879 both commands "break func()" and "break B::func()" set a breakpoint
882 You can use the new flag "-qualified" to override this. This makes
883 GDB interpret the specified function name as a complete
884 fully-qualified name instead. For example, using the same C++
885 program, the "break -q B::func" command sets a breakpoint on
886 "B::func", only. A parameter has been added to the Python
887 gdb.Breakpoint constructor to achieve the same result when creating
888 a breakpoint from Python.
890 * Breakpoints on functions marked with C++ ABI tags
892 GDB can now set breakpoints on functions marked with C++ ABI tags
893 (e.g., [abi:cxx11]). See here for a description of ABI tags:
894 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
896 Functions with a C++11 abi tag are demangled/displayed like this:
898 function[abi:cxx11](int)
901 You can now set a breakpoint on such functions simply as if they had
904 (gdb) b function(int)
906 Or if you need to disambiguate between tags, like:
908 (gdb) b function[abi:other_tag](int)
910 Tab completion was adjusted accordingly as well.
914 ** New events gdb.new_inferior, gdb.inferior_deleted, and
915 gdb.new_thread are emitted. See the manual for further
916 description of these.
918 ** A new function, "gdb.rbreak" has been added to the Python API.
919 This function allows the setting of a large number of breakpoints
920 via a regex pattern in Python. See the manual for further details.
922 ** Python breakpoints can now accept explicit locations. See the
923 manual for a further description of this feature.
926 * New features in the GDB remote stub, GDBserver
928 ** GDBserver is now able to start inferior processes with a
929 specified initial working directory.
931 The user can set the desired working directory to be used from
932 GDB using the new "set cwd" command.
934 ** New "--selftest" command line option runs some GDBserver self
935 tests. These self tests are disabled in releases.
937 ** On Unix systems, GDBserver now does globbing expansion and variable
938 substitution in inferior command line arguments.
940 This is done by starting inferiors using a shell, like GDB does.
941 See "set startup-with-shell" in the user manual for how to disable
942 this from GDB when using "target extended-remote". When using
943 "target remote", you can disable the startup with shell by using the
944 new "--no-startup-with-shell" GDBserver command line option.
946 ** On Unix systems, GDBserver now supports receiving environment
947 variables that are to be set or unset from GDB. These variables
948 will affect the environment to be passed to the inferior.
950 * When catching an Ada exception raised with a message, GDB now prints
951 the message in the catchpoint hit notification. In GDB/MI mode, that
952 information is provided as an extra field named "exception-message"
953 in the *stopped notification.
955 * Trait objects can now be inspected When debugging Rust code. This
956 requires compiler support which will appear in Rust 1.24.
960 QEnvironmentHexEncoded
961 Inform GDBserver of an environment variable that is to be passed to
962 the inferior when starting it.
965 Inform GDBserver of an environment variable that is to be unset
966 before starting the remote inferior.
969 Inform GDBserver that the environment should be reset (i.e.,
970 user-set environment variables should be unset).
973 Indicates whether the inferior must be started with a shell or not.
976 Tell GDBserver that the inferior to be started should use a specific
979 * The "maintenance print c-tdesc" command now takes an optional
980 argument which is the file name of XML target description.
982 * The "maintenance selftest" command now takes an optional argument to
983 filter the tests to be run.
985 * The "enable", and "disable" commands now accept a range of
986 breakpoint locations, e.g. "enable 1.3-5".
991 Set and show the current working directory for the inferior.
994 Set and show compilation command used for compiling and injecting code
995 with the 'compile' commands.
997 set debug separate-debug-file
998 show debug separate-debug-file
999 Control the display of debug output about separate debug file search.
1001 set dump-excluded-mappings
1002 show dump-excluded-mappings
1003 Control whether mappings marked with the VM_DONTDUMP flag should be
1004 dumped when generating a core file.
1006 maint info selftests
1007 List the registered selftests.
1010 Start the debugged program stopping at the first instruction.
1013 Control display of debugging messages related to OpenRISC targets.
1015 set|show print type nested-type-limit
1016 Set and show the limit of nesting level for nested types that the
1017 type printer will show.
1019 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1022 * Safer/improved support for debugging with no debug info
1024 GDB no longer assumes functions with no debug information return
1027 This means that GDB now refuses to call such functions unless you
1028 tell it the function's type, by either casting the call to the
1029 declared return type, or by casting the function to a function
1030 pointer of the right type, and calling that:
1032 (gdb) p getenv ("PATH")
1033 'getenv' has unknown return type; cast the call to its declared return type
1034 (gdb) p (char *) getenv ("PATH")
1035 $1 = 0x7fffffffe "/usr/local/bin:/"...
1036 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1037 $2 = 0x7fffffffe "/usr/local/bin:/"...
1039 Similarly, GDB no longer assumes that global variables with no debug
1040 info have type 'int', and refuses to print the variable's value
1041 unless you tell it the variable's type:
1044 'var' has unknown type; cast it to its declared type
1048 * New native configurations
1050 FreeBSD/aarch64 aarch64*-*-freebsd*
1051 FreeBSD/arm arm*-*-freebsd*
1055 FreeBSD/aarch64 aarch64*-*-freebsd*
1056 FreeBSD/arm arm*-*-freebsd*
1057 OpenRISC ELF or1k*-*-elf
1059 * Removed targets and native configurations
1061 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1063 *** Changes in GDB 8.0
1065 * GDB now supports access to the PKU register on GNU/Linux. The register is
1066 added by the Memory Protection Keys for Userspace feature which will be
1067 available in future Intel CPUs.
1069 * GDB now supports C++11 rvalue references.
1073 ** New functions to start, stop and access a running btrace recording.
1074 ** Rvalue references are now supported in gdb.Type.
1076 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1079 * Building GDB and GDBserver now requires a C++11 compiler.
1081 For example, GCC 4.8 or later.
1083 It is no longer possible to build GDB or GDBserver with a C
1084 compiler. The --disable-build-with-cxx configure option has been
1087 * Building GDB and GDBserver now requires GNU make >= 3.81.
1089 It is no longer supported to build GDB or GDBserver with another
1090 implementation of the make program or an earlier version of GNU make.
1092 * Native debugging on MS-Windows supports command-line redirection
1094 Command-line arguments used for starting programs on MS-Windows can
1095 now include redirection symbols supported by native Windows shells,
1096 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1097 as "run", "start", and "set args", as well as the corresponding MI
1100 * Support for thread names on MS-Windows.
1102 GDB now catches and handles the special exception that programs
1103 running on MS-Windows use to assign names to threads in the
1106 * Support for Java programs compiled with gcj has been removed.
1108 * User commands now accept an unlimited number of arguments.
1109 Previously, only up to 10 was accepted.
1111 * The "eval" command now expands user-defined command arguments.
1113 This makes it easier to process a variable number of arguments:
1118 eval "print $arg%d", $i
1123 * Target descriptions can now describe registers for sparc32 and sparc64.
1125 * GDB now supports DWARF version 5 (debug information format).
1126 Its .debug_names index is not yet supported.
1128 * New native configurations
1130 FreeBSD/mips mips*-*-freebsd
1134 Synopsys ARC arc*-*-elf32
1135 FreeBSD/mips mips*-*-freebsd
1137 * Removed targets and native configurations
1139 Alpha running FreeBSD alpha*-*-freebsd*
1140 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1145 Erases all the flash memory regions reported by the target.
1147 maint print arc arc-instruction address
1148 Print internal disassembler information about instruction at a given address.
1152 set disassembler-options
1153 show disassembler-options
1154 Controls the passing of target specific information to the disassembler.
1155 If it is necessary to specify more than one disassembler option then
1156 multiple options can be placed together into a comma separated list.
1157 The default value is the empty string. Currently, the only supported
1158 targets are ARM, PowerPC and S/390.
1163 Erases all the flash memory regions reported by the target. This is
1164 equivalent to the CLI command flash-erase.
1166 -file-list-shared-libraries
1167 List the shared libraries in the program. This is
1168 equivalent to the CLI command "info shared".
1171 Catchpoints stopping the program when Ada exceptions are
1172 handled. This is equivalent to the CLI command "catch handlers".
1174 *** Changes in GDB 7.12
1176 * GDB and GDBserver now build with a C++ compiler by default.
1178 The --enable-build-with-cxx configure option is now enabled by
1179 default. One must now explicitly configure with
1180 --disable-build-with-cxx in order to build with a C compiler. This
1181 option will be removed in a future release.
1183 * GDBserver now supports recording btrace without maintaining an active
1186 * GDB now supports a negative repeat count in the 'x' command to examine
1187 memory backward from the given address. For example:
1190 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1191 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1192 (gdb) x/-5i 0x0000000000400580
1193 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1194 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1195 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1196 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1197 0x40057b <main(int, char**)+25>:
1198 callq 0x400536 <Func1(int, char const*)>
1200 * Fortran: Support structures with fields of dynamic types and
1201 arrays of dynamic types.
1203 * The symbol dumping maintenance commands have new syntax.
1204 maint print symbols [-pc address] [--] [filename]
1205 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1206 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1207 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1208 maint print msymbols [-objfile objfile] [--] [filename]
1210 * GDB now supports multibit bitfields and enums in target register
1213 * New Python-based convenience function $_as_string(val), which returns
1214 the textual representation of a value. This function is especially
1215 useful to obtain the text label of an enum value.
1217 * Intel MPX bound violation handling.
1219 Segmentation faults caused by a Intel MPX boundary violation
1220 now display the kind of violation (upper or lower), the memory
1221 address accessed and the memory bounds, along with the usual
1222 signal received and code location.
1226 Program received signal SIGSEGV, Segmentation fault
1227 Upper bound violation while accessing address 0x7fffffffc3b3
1228 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1229 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1231 * Rust language support.
1232 GDB now supports debugging programs written in the Rust programming
1233 language. See https://www.rust-lang.org/ for more information about
1236 * Support for running interpreters on specified input/output devices
1238 GDB now supports a new mechanism that allows frontends to provide
1239 fully featured GDB console views, as a better alternative to
1240 building such views on top of the "-interpreter-exec console"
1241 command. See the new "new-ui" command below. With that command,
1242 frontends can now start GDB in the traditional command-line mode
1243 running in an embedded terminal emulator widget, and create a
1244 separate MI interpreter running on a specified i/o device. In this
1245 way, GDB handles line editing, history, tab completion, etc. in the
1246 console all by itself, and the GUI uses the separate MI interpreter
1247 for its own control and synchronization, invisible to the command
1250 * The "catch syscall" command catches groups of related syscalls.
1252 The "catch syscall" command now supports catching a group of related
1253 syscalls using the 'group:' or 'g:' prefix.
1258 skip -gfile file-glob-pattern
1259 skip -function function
1260 skip -rfunction regular-expression
1261 A generalized form of the skip command, with new support for
1262 glob-style file names and regular expressions for function names.
1263 Additionally, a file spec and a function spec may now be combined.
1265 maint info line-table REGEXP
1266 Display the contents of GDB's internal line table data struture.
1269 Run any GDB unit tests that were compiled in.
1272 Start a new user interface instance running INTERP as interpreter,
1273 using the TTY file for input/output.
1277 ** gdb.Breakpoint objects have a new attribute "pending", which
1278 indicates whether the breakpoint is pending.
1279 ** Three new breakpoint-related events have been added:
1280 gdb.breakpoint_created, gdb.breakpoint_modified, and
1281 gdb.breakpoint_deleted.
1283 signal-event EVENTID
1284 Signal ("set") the given MS-Windows event object. This is used in
1285 conjunction with the Windows JIT debugging (AeDebug) support, where
1286 the OS suspends a crashing process until a debugger can attach to
1287 it. Resuming the crashing process, in order to debug it, is done by
1288 signalling an event.
1290 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1291 was added in GDBserver, including JIT compiling fast tracepoint's
1292 conditional expression bytecode into native code.
1294 * Support for various remote target protocols and ROM monitors has
1297 target m32rsdi Remote M32R debugging over SDI
1298 target mips MIPS remote debugging protocol
1299 target pmon PMON ROM monitor
1300 target ddb NEC's DDB variant of PMON for Vr4300
1301 target rockhopper NEC RockHopper variant of PMON
1302 target lsi LSI variant of PMO
1304 * Support for tracepoints and fast tracepoints on powerpc-linux,
1305 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1306 including JIT compiling fast tracepoint's conditional expression
1307 bytecode into native code.
1309 * MI async record =record-started now includes the method and format used for
1310 recording. For example:
1312 =record-started,thread-group="i1",method="btrace",format="bts"
1314 * MI async record =thread-selected now includes the frame field. For example:
1316 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1320 Andes NDS32 nds32*-*-elf
1322 *** Changes in GDB 7.11
1324 * GDB now supports debugging kernel-based threads on FreeBSD.
1326 * Per-inferior thread numbers
1328 Thread numbers are now per inferior instead of global. If you're
1329 debugging multiple inferiors, GDB displays thread IDs using a
1330 qualified INF_NUM.THR_NUM form. For example:
1334 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1335 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1336 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1337 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1339 As consequence, thread numbers as visible in the $_thread
1340 convenience variable and in Python's InferiorThread.num attribute
1341 are no longer unique between inferiors.
1343 GDB now maintains a second thread ID per thread, referred to as the
1344 global thread ID, which is the new equivalent of thread numbers in
1345 previous releases. See also $_gthread below.
1347 For backwards compatibility, MI's thread IDs always refer to global
1350 * Commands that accept thread IDs now accept the qualified
1351 INF_NUM.THR_NUM form as well. For example:
1354 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1357 * In commands that accept a list of thread IDs, you can now refer to
1358 all threads of an inferior using a star wildcard. GDB accepts
1359 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1360 refer to all threads of the current inferior. For example, "info
1363 * You can use "info threads -gid" to display the global thread ID of
1366 * The new convenience variable $_gthread holds the global number of
1369 * The new convenience variable $_inferior holds the number of the
1372 * GDB now displays the ID and name of the thread that hit a breakpoint
1373 or received a signal, if your program is multi-threaded. For
1376 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1377 Thread 1 "main" received signal SIGINT, Interrupt.
1379 * Record btrace now supports non-stop mode.
1381 * Support for tracepoints on aarch64-linux was added in GDBserver.
1383 * The 'record instruction-history' command now indicates speculative execution
1384 when using the Intel Processor Trace recording format.
1386 * GDB now allows users to specify explicit locations, bypassing
1387 the linespec parser. This feature is also available to GDB/MI
1390 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1391 GDB now is able to debug both AArch64 applications and ARM applications
1394 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1395 including JIT compiling fast tracepoint's conditional expression bytecode
1398 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1400 * "info threads", "info inferiors", "info display", "info checkpoints"
1401 and "maint info program-spaces" now list the corresponding items in
1402 ascending ID order, for consistency with all other "info" commands.
1404 * In Ada, the overloads selection menu has been enhanced to display the
1405 parameter types and the return types for the matching overloaded subprograms.
1409 maint set target-non-stop (on|off|auto)
1410 maint show target-non-stop
1411 Control whether GDB targets always operate in non-stop mode even if
1412 "set non-stop" is "off". The default is "auto", meaning non-stop
1413 mode is enabled if supported by the target.
1415 maint set bfd-sharing
1416 maint show bfd-sharing
1417 Control the reuse of bfd objects.
1420 show debug bfd-cache
1421 Control display of debugging info regarding bfd caching.
1425 Control display of debugging info regarding FreeBSD threads.
1427 set remote multiprocess-extensions-packet
1428 show remote multiprocess-extensions-packet
1429 Set/show the use of the remote protocol multiprocess extensions.
1431 set remote thread-events
1432 show remote thread-events
1433 Set/show the use of thread create/exit events.
1435 set ada print-signatures on|off
1436 show ada print-signatures"
1437 Control whether parameter types and return types are displayed in overloads
1438 selection menus. It is activaled (@code{on}) by default.
1442 Controls the maximum size of memory, in bytes, that GDB will
1443 allocate for value contents. Prevents incorrect programs from
1444 causing GDB to allocate overly large buffers. Default is 64k.
1446 * The "disassemble" command accepts a new modifier: /s.
1447 It prints mixed source+disassembly like /m with two differences:
1448 - disassembled instructions are now printed in program order, and
1449 - and source for all relevant files is now printed.
1450 The "/m" option is now considered deprecated: its "source-centric"
1451 output hasn't proved useful in practice.
1453 * The "record instruction-history" command accepts a new modifier: /s.
1454 It behaves exactly like /m and prints mixed source+disassembly.
1456 * The "set scheduler-locking" command supports a new mode "replay".
1457 It behaves like "off" in record mode and like "on" in replay mode.
1459 * Support for various ROM monitors has been removed:
1461 target dbug dBUG ROM monitor for Motorola ColdFire
1462 target picobug Motorola picobug monitor
1463 target dink32 DINK32 ROM monitor for PowerPC
1464 target m32r Renesas M32R/D ROM monitor
1465 target mon2000 mon2000 ROM monitor
1466 target ppcbug PPCBUG ROM monitor for PowerPC
1468 * Support for reading/writing memory and extracting values on architectures
1469 whose memory is addressable in units of any integral multiple of 8 bits.
1472 Allows to break when an Ada exception is handled.
1474 * New remote packets
1477 Indicates that an exec system call was executed.
1479 exec-events feature in qSupported
1480 The qSupported packet allows GDB to request support for exec
1481 events using the new 'gdbfeature' exec-event, and the qSupported
1482 response can contain the corresponding 'stubfeature'. Set and
1483 show commands can be used to display whether these features are enabled.
1486 Equivalent to interrupting with the ^C character, but works in
1489 thread created stop reason (T05 create:...)
1490 Indicates that the thread was just created and is stopped at entry.
1492 thread exit stop reply (w exitcode;tid)
1493 Indicates that the thread has terminated.
1496 Enables/disables thread create and exit event reporting. For
1497 example, this is used in non-stop mode when GDB stops a set of
1498 threads and synchronously waits for the their corresponding stop
1499 replies. Without exit events, if one of the threads exits, GDB
1500 would hang forever not knowing that it should no longer expect a
1501 stop for that same thread.
1504 Indicates that there are no resumed threads left in the target (all
1505 threads are stopped). The remote stub reports support for this stop
1506 reply to GDB's qSupported query.
1509 Enables/disables catching syscalls from the inferior process.
1510 The remote stub reports support for this packet to GDB's qSupported query.
1512 syscall_entry stop reason
1513 Indicates that a syscall was just called.
1515 syscall_return stop reason
1516 Indicates that a syscall just returned.
1518 * Extended-remote exec events
1520 ** GDB now has support for exec events on extended-remote Linux targets.
1521 For such targets with Linux kernels 2.5.46 and later, this enables
1522 follow-exec-mode and exec catchpoints.
1524 set remote exec-event-feature-packet
1525 show remote exec-event-feature-packet
1526 Set/show the use of the remote exec event feature.
1528 * Thread names in remote protocol
1530 The reply to qXfer:threads:read may now include a name attribute for each
1533 * Target remote mode fork and exec events
1535 ** GDB now has support for fork and exec events on target remote mode
1536 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1537 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1538 fork and exec catchpoints.
1540 * Remote syscall events
1542 ** GDB now has support for catch syscall on remote Linux targets,
1543 currently enabled on x86/x86_64 architectures.
1545 set remote catch-syscall-packet
1546 show remote catch-syscall-packet
1547 Set/show the use of the remote catch syscall feature.
1551 ** The -var-set-format command now accepts the zero-hexadecimal
1552 format. It outputs data in hexadecimal format with zero-padding on the
1557 ** gdb.InferiorThread objects have a new attribute "global_num",
1558 which refers to the thread's global thread ID. The existing
1559 "num" attribute now refers to the thread's per-inferior number.
1560 See "Per-inferior thread numbers" above.
1561 ** gdb.InferiorThread objects have a new attribute "inferior", which
1562 is the Inferior object the thread belongs to.
1564 *** Changes in GDB 7.10
1566 * Support for process record-replay and reverse debugging on aarch64*-linux*
1567 targets has been added. GDB now supports recording of A64 instruction set
1568 including advance SIMD instructions.
1570 * Support for Sun's version of the "stabs" debug file format has been removed.
1572 * GDB now honors the content of the file /proc/PID/coredump_filter
1573 (PID is the process ID) on GNU/Linux systems. This file can be used
1574 to specify the types of memory mappings that will be included in a
1575 corefile. For more information, please refer to the manual page of
1576 "core(5)". GDB also has a new command: "set use-coredump-filter
1577 on|off". It allows to set whether GDB will read the content of the
1578 /proc/PID/coredump_filter file when generating a corefile.
1580 * The "info os" command on GNU/Linux can now display information on
1582 "info os cpus" Listing of all cpus/cores on the system
1584 * GDB has two new commands: "set serial parity odd|even|none" and
1585 "show serial parity". These allows to set or show parity for the
1588 * The "info source" command now displays the producer string if it was
1589 present in the debug info. This typically includes the compiler version
1590 and may include things like its command line arguments.
1592 * The "info dll", an alias of the "info sharedlibrary" command,
1593 is now available on all platforms.
1595 * Directory names supplied to the "set sysroot" commands may be
1596 prefixed with "target:" to tell GDB to access shared libraries from
1597 the target system, be it local or remote. This replaces the prefix
1598 "remote:". The default sysroot has been changed from "" to
1599 "target:". "remote:" is automatically converted to "target:" for
1600 backward compatibility.
1602 * The system root specified by "set sysroot" will be prepended to the
1603 filename of the main executable (if reported to GDB as absolute by
1604 the operating system) when starting processes remotely, and when
1605 attaching to already-running local or remote processes.
1607 * GDB now supports automatic location and retrieval of executable
1608 files from remote targets. Remote debugging can now be initiated
1609 using only a "target remote" or "target extended-remote" command
1610 (no "set sysroot" or "file" commands are required). See "New remote
1613 * The "dump" command now supports verilog hex format.
1615 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1617 * On GNU/Linux, GDB and gdbserver are now able to access executable
1618 and shared library files without a "set sysroot" command when
1619 attaching to processes running in different mount namespaces from
1620 the debugger. This makes it possible to attach to processes in
1621 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1622 See "New remote packets" below.
1624 * The "tui reg" command now provides completion for all of the
1625 available register groups, including target specific groups.
1627 * The HISTSIZE environment variable is no longer read when determining
1628 the size of GDB's command history. GDB now instead reads the dedicated
1629 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1630 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1635 ** Memory ports can now be unbuffered.
1639 ** gdb.Objfile objects have a new attribute "username",
1640 which is the name of the objfile as specified by the user,
1641 without, for example, resolving symlinks.
1642 ** You can now write frame unwinders in Python.
1643 ** gdb.Type objects have a new method "optimized_out",
1644 returning optimized out gdb.Value instance of this type.
1645 ** gdb.Value objects have new methods "reference_value" and
1646 "const_value" which return a reference to the value and a
1647 "const" version of the value respectively.
1651 maint print symbol-cache
1652 Print the contents of the symbol cache.
1654 maint print symbol-cache-statistics
1655 Print statistics of symbol cache usage.
1657 maint flush-symbol-cache
1658 Flush the contents of the symbol cache.
1662 Start branch trace recording using Branch Trace Store (BTS) format.
1665 Evaluate expression by using the compiler and print result.
1669 Explicit commands for enabling and disabling tui mode.
1672 set mpx bound on i386 and amd64
1673 Support for bound table investigation on Intel MPX enabled applications.
1677 Start branch trace recording using Intel Processor Trace format.
1680 Print information about branch tracing internals.
1682 maint btrace packet-history
1683 Print the raw branch tracing data.
1685 maint btrace clear-packet-history
1686 Discard the stored raw branch tracing data.
1689 Discard all branch tracing data. It will be fetched and processed
1690 anew by the next "record" command.
1695 Renamed from "set debug dwarf2-die".
1696 show debug dwarf-die
1697 Renamed from "show debug dwarf2-die".
1699 set debug dwarf-read
1700 Renamed from "set debug dwarf2-read".
1701 show debug dwarf-read
1702 Renamed from "show debug dwarf2-read".
1704 maint set dwarf always-disassemble
1705 Renamed from "maint set dwarf2 always-disassemble".
1706 maint show dwarf always-disassemble
1707 Renamed from "maint show dwarf2 always-disassemble".
1709 maint set dwarf max-cache-age
1710 Renamed from "maint set dwarf2 max-cache-age".
1711 maint show dwarf max-cache-age
1712 Renamed from "maint show dwarf2 max-cache-age".
1714 set debug dwarf-line
1715 show debug dwarf-line
1716 Control display of debugging info regarding DWARF line processing.
1719 show max-completions
1720 Set the maximum number of candidates to be considered during
1721 completion. The default value is 200. This limit allows GDB
1722 to avoid generating large completion lists, the computation of
1723 which can cause the debugger to become temporarily unresponsive.
1725 set history remove-duplicates
1726 show history remove-duplicates
1727 Control the removal of duplicate history entries.
1729 maint set symbol-cache-size
1730 maint show symbol-cache-size
1731 Control the size of the symbol cache.
1733 set|show record btrace bts buffer-size
1734 Set and show the size of the ring buffer used for branch tracing in
1736 The obtained size may differ from the requested size. Use "info
1737 record" to see the obtained buffer size.
1739 set debug linux-namespaces
1740 show debug linux-namespaces
1741 Control display of debugging info regarding Linux namespaces.
1743 set|show record btrace pt buffer-size
1744 Set and show the size of the ring buffer used for branch tracing in
1745 Intel Processor Trace format.
1746 The obtained size may differ from the requested size. Use "info
1747 record" to see the obtained buffer size.
1749 maint set|show btrace pt skip-pad
1750 Set and show whether PAD packets are skipped when computing the
1753 * The command 'thread apply all' can now support new option '-ascending'
1754 to call its specified command for all threads in ascending order.
1756 * Python/Guile scripting
1758 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1759 special section named `.debug_gdb_scripts'.
1761 * New remote packets
1763 qXfer:btrace-conf:read
1764 Return the branch trace configuration for the current thread.
1766 Qbtrace-conf:bts:size
1767 Set the requested ring buffer size for branch tracing in BTS format.
1770 Enable Intel Procesor Trace-based branch tracing for the current
1771 process. The remote stub reports support for this packet to GDB's
1774 Qbtrace-conf:pt:size
1775 Set the requested ring buffer size for branch tracing in Intel Processor
1779 Indicates a memory breakpoint instruction was executed, irrespective
1780 of whether it was GDB that planted the breakpoint or the breakpoint
1781 is hardcoded in the program. This is required for correct non-stop
1785 Indicates the target stopped for a hardware breakpoint. This is
1786 required for correct non-stop mode operation.
1789 Return information about files on the remote system.
1791 qXfer:exec-file:read
1792 Return the full absolute name of the file that was executed to
1793 create a process running on the remote system.
1796 Select the filesystem on which vFile: operations with filename
1797 arguments will operate. This is required for GDB to be able to
1798 access files on remote targets where the remote stub does not
1799 share a common filesystem with the inferior(s).
1802 Indicates that a fork system call was executed.
1805 Indicates that a vfork system call was executed.
1807 vforkdone stop reason
1808 Indicates that a vfork child of the specified process has executed
1809 an exec or exit, allowing the vfork parent to resume execution.
1811 fork-events and vfork-events features in qSupported
1812 The qSupported packet allows GDB to request support for fork and
1813 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1814 and the qSupported response can contain the corresponding
1815 'stubfeatures'. Set and show commands can be used to display
1816 whether these features are enabled.
1818 * Extended-remote fork events
1820 ** GDB now has support for fork events on extended-remote Linux
1821 targets. For targets with Linux kernels 2.5.60 and later, this
1822 enables follow-fork-mode and detach-on-fork for both fork and
1823 vfork, as well as fork and vfork catchpoints.
1825 * The info record command now shows the recording format and the
1826 branch tracing configuration for the current thread when using
1827 the btrace record target.
1828 For the BTS format, it shows the ring buffer size.
1830 * GDB now has support for DTrace USDT (Userland Static Defined
1831 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1833 * GDB now supports access to vector registers on S/390 GNU/Linux
1836 * Removed command line options
1838 -xdb HP-UX XDB compatibility mode.
1840 * Removed targets and native configurations
1842 HP/PA running HP-UX hppa*-*-hpux*
1843 Itanium running HP-UX ia64-*-hpux*
1845 * New configure options
1848 This configure option allows the user to build GDB with support for
1849 Intel Processor Trace (default: auto). This requires libipt.
1851 --with-libipt-prefix=PATH
1852 Specify the path to the version of libipt that GDB should use.
1853 $PATH/include should contain the intel-pt.h header and
1854 $PATH/lib should contain the libipt.so library.
1856 *** Changes in GDB 7.9.1
1860 ** Xmethods can now specify a result type.
1862 *** Changes in GDB 7.9
1864 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1868 ** You can now access frame registers from Python scripts.
1869 ** New attribute 'producer' for gdb.Symtab objects.
1870 ** gdb.Objfile objects have a new attribute "progspace",
1871 which is the gdb.Progspace object of the containing program space.
1872 ** gdb.Objfile objects have a new attribute "owner".
1873 ** gdb.Objfile objects have a new attribute "build_id",
1874 which is the build ID generated when the file was built.
1875 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1876 ** A new event "gdb.clear_objfiles" has been added, triggered when
1877 selecting a new file to debug.
1878 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1879 ** New function gdb.lookup_objfile.
1881 New events which are triggered when GDB modifies the state of the
1884 ** gdb.events.inferior_call_pre: Function call is about to be made.
1885 ** gdb.events.inferior_call_post: Function call has just been made.
1886 ** gdb.events.memory_changed: A memory location has been altered.
1887 ** gdb.events.register_changed: A register has been altered.
1889 * New Python-based convenience functions:
1891 ** $_caller_is(name [, number_of_frames])
1892 ** $_caller_matches(regexp [, number_of_frames])
1893 ** $_any_caller_is(name [, number_of_frames])
1894 ** $_any_caller_matches(regexp [, number_of_frames])
1896 * GDB now supports the compilation and injection of source code into
1897 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1898 to compile the source code to object code, and if successful, inject
1899 and execute that code within the current context of the inferior.
1900 Currently the C language is supported. The commands used to
1901 interface with this new feature are:
1903 compile code [-raw|-r] [--] [source code]
1904 compile file [-raw|-r] filename
1908 demangle [-l language] [--] name
1909 Demangle "name" in the specified language, or the current language
1910 if elided. This command is renamed from the "maint demangle" command.
1911 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1912 as "maint demangler-warning".
1914 queue-signal signal-name-or-number
1915 Queue a signal to be delivered to the thread when it is resumed.
1917 add-auto-load-scripts-directory directory
1918 Add entries to the list of directories from which to load auto-loaded
1921 maint print user-registers
1922 List all currently available "user" registers.
1924 compile code [-r|-raw] [--] [source code]
1925 Compile, inject, and execute in the inferior the executable object
1926 code produced by compiling the provided source code.
1928 compile file [-r|-raw] filename
1929 Compile and inject into the inferior the executable object code
1930 produced by compiling the source code stored in the filename
1933 * On resume, GDB now always passes the signal the program had stopped
1934 for to the thread the signal was sent to, even if the user changed
1935 threads before resuming. Previously GDB would often (but not
1936 always) deliver the signal to the thread that happens to be current
1939 * Conversely, the "signal" command now consistently delivers the
1940 requested signal to the current thread. GDB now asks for
1941 confirmation if the program had stopped for a signal and the user
1942 switched threads meanwhile.
1944 * "breakpoint always-inserted" modes "off" and "auto" merged.
1946 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1947 won't remove breakpoints from the target until all threads stop,
1948 even in non-stop mode. The "auto" mode has been removed, and "off"
1949 is now the default mode.
1953 set debug symbol-lookup
1954 show debug symbol-lookup
1955 Control display of debugging info regarding symbol lookup.
1959 ** The -list-thread-groups command outputs an exit-code field for
1960 inferiors that have exited.
1964 MIPS SDE mips*-sde*-elf*
1968 Support for these obsolete configurations has been removed.
1970 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1971 SGI Irix-5.x mips-*-irix5*
1972 SGI Irix-6.x mips-*-irix6*
1973 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1974 VAX running Ultrix vax-*-ultrix*
1976 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1977 and "assf"), have been removed. Use the "sharedlibrary" command, or
1978 its alias "share", instead.
1980 *** Changes in GDB 7.8
1982 * New command line options
1985 This is an alias for the --data-directory option.
1987 * GDB supports printing and modifying of variable length automatic arrays
1988 as specified in ISO C99.
1990 * The ARM simulator now supports instruction level tracing
1991 with or without disassembly.
1995 GDB now has support for scripting using Guile. Whether this is
1996 available is determined at configure time.
1997 Guile version 2.0 or greater is required.
1998 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2000 * New commands (for set/show, see "New options" below)
2004 Invoke CODE by passing it to the Guile interpreter.
2008 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2010 info auto-load guile-scripts [regexp]
2011 Print the list of automatically loaded Guile scripts.
2013 * The source command is now capable of sourcing Guile scripts.
2014 This feature is dependent on the debugger being built with Guile support.
2018 set print symbol-loading (off|brief|full)
2019 show print symbol-loading
2020 Control whether to print informational messages when loading symbol
2021 information for a file. The default is "full", but when debugging
2022 programs with large numbers of shared libraries the amount of output
2023 becomes less useful.
2025 set guile print-stack (none|message|full)
2026 show guile print-stack
2027 Show a stack trace when an error is encountered in a Guile script.
2029 set auto-load guile-scripts (on|off)
2030 show auto-load guile-scripts
2031 Control auto-loading of Guile script files.
2033 maint ada set ignore-descriptive-types (on|off)
2034 maint ada show ignore-descriptive-types
2035 Control whether the debugger should ignore descriptive types in Ada
2036 programs. The default is not to ignore the descriptive types. See
2037 the user manual for more details on descriptive types and the intended
2038 usage of this option.
2040 set auto-connect-native-target
2042 Control whether GDB is allowed to automatically connect to the
2043 native target for the run, attach, etc. commands when not connected
2044 to any target yet. See also "target native" below.
2046 set record btrace replay-memory-access (read-only|read-write)
2047 show record btrace replay-memory-access
2048 Control what memory accesses are allowed during replay.
2050 maint set target-async (on|off)
2051 maint show target-async
2052 This controls whether GDB targets operate in synchronous or
2053 asynchronous mode. Normally the default is asynchronous, if it is
2054 available; but this can be changed to more easily debug problems
2055 occurring only in synchronous mode.
2057 set mi-async (on|off)
2059 Control whether MI asynchronous mode is preferred. This supersedes
2060 "set target-async" of previous GDB versions.
2062 * "set target-async" is deprecated as a CLI option and is now an alias
2063 for "set mi-async" (only puts MI into async mode).
2065 * Background execution commands (e.g., "c&", "s&", etc.) are now
2066 possible ``out of the box'' if the target supports them. Previously
2067 the user would need to explicitly enable the possibility with the
2068 "set target-async on" command.
2070 * New features in the GDB remote stub, GDBserver
2072 ** New option --debug-format=option1[,option2,...] allows one to add
2073 additional text to each output. At present only timestamps
2074 are supported: --debug-format=timestamps.
2075 Timestamps can also be turned on with the
2076 "monitor set debug-format timestamps" command from GDB.
2078 * The 'record instruction-history' command now starts counting instructions
2079 at one. This also affects the instruction ranges reported by the
2080 'record function-call-history' command when given the /i modifier.
2082 * The command 'record function-call-history' supports a new modifier '/c' to
2083 indent the function names based on their call stack depth.
2084 The fields for the '/i' and '/l' modifier have been reordered.
2085 The source line range is now prefixed with 'at'.
2086 The instruction range is now prefixed with 'inst'.
2087 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2088 "record instruction-history" and "list" commands.
2090 * The ranges given as arguments to the 'record function-call-history' and
2091 'record instruction-history' commands are now inclusive.
2093 * The btrace record target now supports the 'record goto' command.
2094 For locations inside the execution trace, the back trace is computed
2095 based on the information stored in the execution trace.
2097 * The btrace record target supports limited reverse execution and replay.
2098 The target does not record data and therefore does not allow reading
2099 memory or registers.
2101 * The "catch syscall" command now works on s390*-linux* targets.
2103 * The "compare-sections" command is no longer specific to target
2104 remote. It now works with all targets.
2106 * All native targets are now consistently called "native".
2107 Consequently, the "target child", "target GNU", "target djgpp",
2108 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2109 commands have been replaced with "target native". The QNX/NTO port
2110 leaves the "procfs" target in place and adds a "native" target for
2111 consistency with other ports. The impact on users should be minimal
2112 as these commands previously either throwed an error, or were
2113 no-ops. The target's name is visible in the output of the following
2114 commands: "help target", "info target", "info files", "maint print
2117 * The "target native" command now connects to the native target. This
2118 can be used to launch native programs even when "set
2119 auto-connect-native-target" is set to off.
2121 * GDB now supports access to Intel MPX registers on GNU/Linux.
2123 * Support for Intel AVX-512 registers on GNU/Linux.
2124 Support displaying and modifying Intel AVX-512 registers
2125 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2127 * New remote packets
2129 qXfer:btrace:read's annex
2130 The qXfer:btrace:read packet supports a new annex 'delta' to read
2131 branch trace incrementally.
2135 ** Valid Python operations on gdb.Value objects representing
2136 structs/classes invoke the corresponding overloaded operators if
2138 ** New `Xmethods' feature in the Python API. Xmethods are
2139 additional methods or replacements for existing methods of a C++
2140 class. This feature is useful for those cases where a method
2141 defined in C++ source code could be inlined or optimized out by
2142 the compiler, making it unavailable to GDB.
2145 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2147 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2148 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2149 its alias "share", instead.
2151 * The commands "set remotebaud" and "show remotebaud" are no longer
2152 supported. Use "set serial baud" and "show serial baud" (respectively)
2157 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2158 target-async". The latter is left as a deprecated alias of the
2159 former for backward compatibility. If the target supports it,
2160 CLI background execution commands are now always possible by
2161 default, independently of whether the frontend stated a
2162 preference for asynchronous execution with "-gdb-set mi-async".
2163 Previously "-gdb-set target-async off" affected both MI execution
2164 commands and CLI execution commands.
2166 *** Changes in GDB 7.7
2168 * Improved support for process record-replay and reverse debugging on
2169 arm*-linux* targets. Support for thumb32 and syscall instruction
2170 recording has been added.
2172 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2174 * GDB now supports Fission DWP file format version 2.
2175 http://gcc.gnu.org/wiki/DebugFission
2177 * New convenience function "$_isvoid", to check whether an expression
2178 is void. A void expression is an expression where the type of the
2179 result is "void". For example, some convenience variables may be
2180 "void" when evaluated (e.g., "$_exitcode" before the execution of
2181 the program being debugged; or an undefined convenience variable).
2182 Another example, when calling a function whose return type is
2185 * The "maintenance print objfiles" command now takes an optional regexp.
2187 * The "catch syscall" command now works on arm*-linux* targets.
2189 * GDB now consistently shows "<not saved>" when printing values of
2190 registers the debug info indicates have not been saved in the frame
2191 and there's nowhere to retrieve them from
2192 (callee-saved/call-clobbered registers):
2197 (gdb) info registers rax
2200 Before, the former would print "<optimized out>", and the latter
2201 "*value not available*".
2203 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2208 ** Frame filters and frame decorators have been added.
2209 ** Temporary breakpoints are now supported.
2210 ** Line tables representation has been added.
2211 ** New attribute 'parent_type' for gdb.Field objects.
2212 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2213 ** New attribute 'name' for gdb.Type objects.
2217 Nios II ELF nios2*-*-elf
2218 Nios II GNU/Linux nios2*-*-linux
2219 Texas Instruments MSP430 msp430*-*-elf
2221 * Removed native configurations
2223 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2224 been removed. ELF variants of these configurations are kept supported.
2226 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2227 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2228 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2229 i[34567]86-*-openbsd3.[0-3]
2230 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2231 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2232 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2236 Like "catch throw", but catches a re-thrown exception.
2237 maint check-psymtabs
2238 Renamed from old "maint check-symtabs".
2240 Perform consistency checks on symtabs.
2241 maint expand-symtabs
2242 Expand symtabs matching an optional regexp.
2245 Display the details of GDB configure-time options.
2247 maint set|show per-command
2248 maint set|show per-command space
2249 maint set|show per-command time
2250 maint set|show per-command symtab
2251 Enable display of per-command gdb resource usage.
2253 remove-symbol-file FILENAME
2254 remove-symbol-file -a ADDRESS
2255 Remove a symbol file added via add-symbol-file. The file to remove
2256 can be identified by its filename or by an address that lies within
2257 the boundaries of this symbol file in memory.
2260 info exceptions REGEXP
2261 Display the list of Ada exceptions defined in the program being
2262 debugged. If provided, only the exceptions whose names match REGEXP
2267 set debug symfile off|on
2269 Control display of debugging info regarding reading symbol files and
2270 symbol tables within those files
2272 set print raw frame-arguments
2273 show print raw frame-arguments
2274 Set/show whether to print frame arguments in raw mode,
2275 disregarding any defined pretty-printers.
2277 set remote trace-status-packet
2278 show remote trace-status-packet
2279 Set/show the use of remote protocol qTStatus packet.
2283 Control display of debugging messages related to Nios II targets.
2287 Control whether target-assisted range stepping is enabled.
2289 set startup-with-shell
2290 show startup-with-shell
2291 Specifies whether Unix child processes are started via a shell or
2296 Use the target memory cache for accesses to the code segment. This
2297 improves performance of remote debugging (particularly disassembly).
2299 * You can now use a literal value 'unlimited' for options that
2300 interpret 0 or -1 as meaning "unlimited". E.g., "set
2301 trace-buffer-size unlimited" is now an alias for "set
2302 trace-buffer-size -1" and "set height unlimited" is now an alias for
2305 * The "set debug symtab-create" debugging option of GDB has been changed to
2306 accept a verbosity level. 0 means "off", 1 provides basic debugging
2307 output, and values of 2 or greater provides more verbose output.
2309 * New command-line options
2311 Display the details of GDB configure-time options.
2313 * The command 'tsave' can now support new option '-ctf' to save trace
2314 buffer in Common Trace Format.
2316 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2319 * GDB now implements the the C++ 'typeid' operator.
2321 * The new convenience variable $_exception holds the exception being
2322 thrown or caught at an exception-related catchpoint.
2324 * The exception-related catchpoints, like "catch throw", now accept a
2325 regular expression which can be used to filter exceptions by type.
2327 * The new convenience variable $_exitsignal is automatically set to
2328 the terminating signal number when the program being debugged dies
2329 due to an uncaught signal.
2333 ** All MI commands now accept an optional "--language" option.
2334 Support for this feature can be verified by using the "-list-features"
2335 command, which should contain "language-option".
2337 ** The new command -info-gdb-mi-command allows the user to determine
2338 whether a GDB/MI command is supported or not.
2340 ** The "^error" result record returned when trying to execute an undefined
2341 GDB/MI command now provides a variable named "code" whose content is the
2342 "undefined-command" error code. Support for this feature can be verified
2343 by using the "-list-features" command, which should contain
2344 "undefined-command-error-code".
2346 ** The -trace-save MI command can optionally save trace buffer in Common
2349 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2351 ** The command -data-list-register-values now accepts an optional
2352 "--skip-unavailable" option. When used, only the available registers
2355 ** The new command -trace-frame-collected dumps collected variables,
2356 computed expressions, tvars, memory and registers in a traceframe.
2358 ** The commands -stack-list-locals, -stack-list-arguments and
2359 -stack-list-variables now accept an option "--skip-unavailable".
2360 When used, only the available locals or arguments are displayed.
2362 ** The -exec-run command now accepts an optional "--start" option.
2363 When used, the command follows the same semantics as the "start"
2364 command, stopping the program's execution at the start of its
2365 main subprogram. Support for this feature can be verified using
2366 the "-list-features" command, which should contain
2367 "exec-run-start-option".
2369 ** The new commands -catch-assert and -catch-exceptions insert
2370 catchpoints stopping the program when Ada exceptions are raised.
2372 ** The new command -info-ada-exceptions provides the equivalent of
2373 the new "info exceptions" command.
2375 * New system-wide configuration scripts
2376 A GDB installation now provides scripts suitable for use as system-wide
2377 configuration scripts for the following systems:
2381 * GDB now supports target-assigned range stepping with remote targets.
2382 This improves the performance of stepping source lines by reducing
2383 the number of control packets from/to GDB. See "New remote packets"
2386 * GDB now understands the element 'tvar' in the XML traceframe info.
2387 It has the id of the collected trace state variables.
2389 * On S/390 targets that provide the transactional-execution feature,
2390 the program interruption transaction diagnostic block (TDB) is now
2391 represented as a number of additional "registers" in GDB.
2393 * New remote packets
2397 The vCont packet supports a new 'r' action, that tells the remote
2398 stub to step through an address range itself, without GDB
2399 involvemement at each single-step.
2401 qXfer:libraries-svr4:read's annex
2402 The previously unused annex of the qXfer:libraries-svr4:read packet
2403 is now used to support passing an argument list. The remote stub
2404 reports support for this argument list to GDB's qSupported query.
2405 The defined arguments are "start" and "prev", used to reduce work
2406 necessary for library list updating, resulting in significant
2409 * New features in the GDB remote stub, GDBserver
2411 ** GDBserver now supports target-assisted range stepping. Currently
2412 enabled on x86/x86_64 GNU/Linux targets.
2414 ** GDBserver now adds element 'tvar' in the XML in the reply to
2415 'qXfer:traceframe-info:read'. It has the id of the collected
2416 trace state variables.
2418 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2421 * New 'z' formatter for printing and examining memory, this displays the
2422 value as hexadecimal zero padded on the left to the size of the type.
2424 * GDB can now use Windows x64 unwinding data.
2426 * The "set remotebaud" command has been replaced by "set serial baud".
2427 Similarly, "show remotebaud" has been replaced by "show serial baud".
2428 The "set remotebaud" and "show remotebaud" commands are still available
2429 to provide backward compatibility with older versions of GDB.
2431 *** Changes in GDB 7.6
2433 * Target record has been renamed to record-full.
2434 Record/replay is now enabled with the "record full" command.
2435 This also affects settings that are associated with full record/replay
2436 that have been moved from "set/show record" to "set/show record full":
2438 set|show record full insn-number-max
2439 set|show record full stop-at-limit
2440 set|show record full memory-query
2442 * A new record target "record-btrace" has been added. The new target
2443 uses hardware support to record the control-flow of a process. It
2444 does not support replaying the execution, but it implements the
2445 below new commands for investigating the recorded execution log.
2446 This new recording method can be enabled using:
2450 The "record-btrace" target is only available on Intel Atom processors
2451 and requires a Linux kernel 2.6.32 or later.
2453 * Two new commands have been added for record/replay to give information
2454 about the recorded execution without having to replay the execution.
2455 The commands are only supported by "record btrace".
2457 record instruction-history prints the execution history at
2458 instruction granularity
2460 record function-call-history prints the execution history at
2461 function granularity
2463 * New native configurations
2465 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2466 FreeBSD/powerpc powerpc*-*-freebsd
2467 x86_64/Cygwin x86_64-*-cygwin*
2468 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2472 ARM AArch64 aarch64*-*-elf
2473 ARM AArch64 GNU/Linux aarch64*-*-linux
2474 Lynx 178 PowerPC powerpc-*-lynx*178
2475 x86_64/Cygwin x86_64-*-cygwin*
2476 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2478 * If the configured location of system.gdbinit file (as given by the
2479 --with-system-gdbinit option at configure time) is in the
2480 data-directory (as specified by --with-gdb-datadir at configure
2481 time) or in one of its subdirectories, then GDB will look for the
2482 system-wide init file in the directory specified by the
2483 --data-directory command-line option.
2485 * New command line options:
2487 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2488 other initialization files, unlike -nx which disables all of them.
2490 * Removed command line options
2492 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2495 * The 'ptype' and 'whatis' commands now accept an argument to control
2498 * 'info proc' now works on some core files.
2502 ** Vectors can be created with gdb.Type.vector.
2504 ** Python's atexit.register now works in GDB.
2506 ** Types can be pretty-printed via a Python API.
2508 ** Python 3 is now supported (in addition to Python 2.4 or later)
2510 ** New class gdb.Architecture exposes GDB's internal representation
2511 of architecture in the Python API.
2513 ** New method Frame.architecture returns the gdb.Architecture object
2514 corresponding to the frame's architecture.
2516 * New Python-based convenience functions:
2518 ** $_memeq(buf1, buf2, length)
2519 ** $_streq(str1, str2)
2521 ** $_regex(str, regex)
2523 * The 'cd' command now defaults to using '~' (the home directory) if not
2526 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2527 default for GCC since November 2000.
2529 * The command 'forward-search' can now be abbreviated as 'fo'.
2531 * The command 'info tracepoints' can now display 'installed on target'
2532 or 'not installed on target' for each non-pending location of tracepoint.
2534 * New configure options
2536 --enable-libmcheck/--disable-libmcheck
2537 By default, development versions are built with -lmcheck on hosts
2538 that support it, in order to help track memory corruption issues.
2539 Release versions, on the other hand, are built without -lmcheck
2540 by default. The --enable-libmcheck/--disable-libmcheck configure
2541 options allow the user to override that default.
2542 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2543 This configure option allows the user to build GDB with
2544 libbabeltrace using which GDB can read Common Trace Format data.
2546 * New commands (for set/show, see "New options" below)
2549 Catch signals. This is similar to "handle", but allows commands and
2550 conditions to be attached.
2553 List the BFDs known to GDB.
2555 python-interactive [command]
2557 Start a Python interactive prompt, or evaluate the optional command
2558 and print the result of expressions.
2561 "py" is a new alias for "python".
2563 enable type-printer [name]...
2564 disable type-printer [name]...
2565 Enable or disable type printers.
2569 ** For the Renesas Super-H architecture, the "regs" command has been removed
2570 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2575 set print type methods (on|off)
2576 show print type methods
2577 Control whether method declarations are displayed by "ptype".
2578 The default is to show them.
2580 set print type typedefs (on|off)
2581 show print type typedefs
2582 Control whether typedef definitions are displayed by "ptype".
2583 The default is to show them.
2585 set filename-display basename|relative|absolute
2586 show filename-display
2587 Control the way in which filenames is displayed.
2588 The default is "relative", which preserves previous behavior.
2590 set trace-buffer-size
2591 show trace-buffer-size
2592 Request target to change the size of trace buffer.
2594 set remote trace-buffer-size-packet auto|on|off
2595 show remote trace-buffer-size-packet
2596 Control the use of the remote protocol `QTBuffer:size' packet.
2600 Control display of debugging messages related to ARM AArch64.
2603 set debug coff-pe-read
2604 show debug coff-pe-read
2605 Control display of debugging messages related to reading of COFF/PE
2610 Control display of debugging messages related to Mach-O symbols
2613 set debug notification
2614 show debug notification
2615 Control display of debugging info for async remote notification.
2619 ** Command parameter changes are now notified using new async record
2620 "=cmd-param-changed".
2621 ** Trace frame changes caused by command "tfind" are now notified using
2622 new async record "=traceframe-changed".
2623 ** The creation, deletion and modification of trace state variables
2624 are now notified using new async records "=tsv-created",
2625 "=tsv-deleted" and "=tsv-modified".
2626 ** The start and stop of process record are now notified using new
2627 async record "=record-started" and "=record-stopped".
2628 ** Memory changes are now notified using new async record
2630 ** The data-disassemble command response will include a "fullname" field
2631 containing the absolute file name when source has been requested.
2632 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2633 command, to allow pattern filling of memory areas.
2634 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2635 library load/unload events.
2636 ** The response to breakpoint commands and breakpoint async records
2637 includes an "installed" field containing a boolean state about each
2638 non-pending tracepoint location is whether installed on target or not.
2639 ** Output of the "-trace-status" command includes a "trace-file" field
2640 containing the name of the trace file being examined. This field is
2641 optional, and only present when examining a trace file.
2642 ** The "fullname" field is now always present along with the "file" field,
2643 even if the file cannot be found by GDB.
2645 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2646 You must have the LZMA library available when configuring GDB for this
2647 feature to be enabled. For more information, see:
2648 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2650 * New remote packets
2653 Set the size of trace buffer. The remote stub reports support for this
2654 packet to gdb's qSupported query.
2657 Enable Branch Trace Store (BTS)-based branch tracing for the current
2658 thread. The remote stub reports support for this packet to gdb's
2662 Disable branch tracing for the current thread. The remote stub reports
2663 support for this packet to gdb's qSupported query.
2666 Read the traced branches for the current thread. The remote stub
2667 reports support for this packet to gdb's qSupported query.
2669 *** Changes in GDB 7.5
2671 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2672 for more x32 ABI info.
2674 * GDB now supports access to MIPS DSP registers on Linux targets.
2676 * GDB now supports debugging microMIPS binaries.
2678 * The "info os" command on GNU/Linux can now display information on
2679 several new classes of objects managed by the operating system:
2680 "info os procgroups" lists process groups
2681 "info os files" lists file descriptors
2682 "info os sockets" lists internet-domain sockets
2683 "info os shm" lists shared-memory regions
2684 "info os semaphores" lists semaphores
2685 "info os msg" lists message queues
2686 "info os modules" lists loaded kernel modules
2688 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2689 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2690 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2691 options and inspect the probe arguments using the new $_probe_arg family
2692 of convenience variables. You can obtain more information about SystemTap
2693 in <http://sourceware.org/systemtap/>.
2695 * GDB now supports reversible debugging on ARM, it allows you to
2696 debug basic ARM and THUMB instructions, and provides
2697 record/replay support.
2699 * The option "symbol-reloading" has been deleted as it is no longer used.
2703 ** GDB commands implemented in Python can now be put in command class
2706 ** The "maint set python print-stack on|off" is now deleted.
2708 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2709 apply "flag enum"-style pretty-printing to any enum.
2711 ** gdb.lookup_symbol can now work when there is no current frame.
2713 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2714 the source at which the symbol was defined.
2716 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2717 method 'value'. The former indicates whether the symbol needs a
2718 frame in order to compute its value, and the latter computes the
2721 ** A new method 'referenced_value' on gdb.Value objects which can
2722 dereference pointer as well as C++ reference values.
2724 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2725 which return the global and static blocks (as gdb.Block objects),
2726 of the underlying symbol table, respectively.
2728 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2729 object associated with a PC value.
2731 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2732 of the address range occupied by code for the current source line.
2734 * Go language support.
2735 GDB now supports debugging programs written in the Go programming
2738 * GDBserver now supports stdio connections.
2739 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2741 * The binary "gdbtui" can no longer be built or installed.
2742 Use "gdb -tui" instead.
2744 * GDB will now print "flag" enums specially. A flag enum is one where
2745 all the enumerator values have no bits in common when pairwise
2746 "and"ed. When printing a value whose type is a flag enum, GDB will
2747 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2748 (gdb) print (enum E) 3
2751 * The filename part of a linespec will now match trailing components
2752 of a source file name. For example, "break gcc/expr.c:1000" will
2753 now set a breakpoint in build/gcc/expr.c, but not
2754 build/libcpp/expr.c.
2756 * The "info proc" and "generate-core-file" commands will now also
2757 work on remote targets connected to GDBserver on Linux.
2759 * The command "info catch" has been removed. It has been disabled
2760 since December 2007.
2762 * The "catch exception" and "catch assert" commands now accept
2763 a condition at the end of the command, much like the "break"
2764 command does. For instance:
2766 (gdb) catch exception Constraint_Error if Barrier = True
2768 Previously, it was possible to add a condition to such catchpoints,
2769 but it had to be done as a second step, after the catchpoint had been
2770 created, using the "condition" command.
2772 * The "info static-tracepoint-marker" command will now also work on
2773 native Linux targets with in-process agent.
2775 * GDB can now set breakpoints on inlined functions.
2777 * The .gdb_index section has been updated to include symbols for
2778 inlined functions. GDB will ignore older .gdb_index sections by
2779 default, which could cause symbol files to be loaded more slowly
2780 until their .gdb_index sections can be recreated. The new command
2781 "set use-deprecated-index-sections on" will cause GDB to use any older
2782 .gdb_index sections it finds. This will restore performance, but the
2783 ability to set breakpoints on inlined functions will be lost in symbol
2784 files with older .gdb_index sections.
2786 The .gdb_index section has also been updated to record more information
2787 about each symbol. This speeds up the "info variables", "info functions"
2788 and "info types" commands when used with programs having the .gdb_index
2789 section, as well as speeding up debugging with shared libraries using
2790 the .gdb_index section.
2792 * Ada support for GDB/MI Variable Objects has been added.
2794 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2799 ** New command -info-os is the MI equivalent of "info os".
2801 ** Output logs ("set logging" and related) now include MI output.
2805 ** "set use-deprecated-index-sections on|off"
2806 "show use-deprecated-index-sections on|off"
2807 Controls the use of deprecated .gdb_index sections.
2809 ** "catch load" and "catch unload" can be used to stop when a shared
2810 library is loaded or unloaded, respectively.
2812 ** "enable count" can be used to auto-disable a breakpoint after
2815 ** "info vtbl" can be used to show the virtual method tables for
2816 C++ and Java objects.
2818 ** "explore" and its sub commands "explore value" and "explore type"
2819 can be used to recursively explore values and types of
2820 expressions. These commands are available only if GDB is
2821 configured with '--with-python'.
2823 ** "info auto-load" shows status of all kinds of auto-loaded files,
2824 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2825 sequences of commands files, "info auto-load python-scripts"
2826 shows status of auto-loading Python script files,
2827 "info auto-load local-gdbinit" shows status of loading init file
2828 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2829 status of inferior specific thread debugging shared library loading.
2831 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2832 and "show auto-load-scripts" commands have been deprecated, use their
2833 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2834 and "show auto-load python-scripts" counterparts instead.
2836 ** "dprintf location,format,args..." creates a dynamic printf, which
2837 is basically a breakpoint that does a printf and immediately
2838 resumes your program's execution, so it is like a printf that you
2839 can insert dynamically at runtime instead of at compiletime.
2841 ** "set print symbol"
2843 Controls whether GDB attempts to display the symbol, if any,
2844 corresponding to addresses it prints. This defaults to "on", but
2845 you can set it to "off" to restore GDB's previous behavior.
2847 * Deprecated commands
2849 ** For the Renesas Super-H architecture, the "regs" command has been
2850 deprecated, and "info all-registers" should be used instead.
2854 Renesas RL78 rl78-*-elf
2855 HP OpenVMS ia64 ia64-hp-openvms*
2857 * GDBserver supports evaluation of breakpoint conditions. When
2858 support is advertised by GDBserver, GDB may be told to send the
2859 breakpoint conditions in bytecode form to GDBserver. GDBserver
2860 will only report the breakpoint trigger to GDB when its condition
2865 set mips compression
2866 show mips compression
2867 Select the compressed ISA encoding used in functions that have no symbol
2868 information available. The encoding can be set to either of:
2871 and is updated automatically from ELF file flags if available.
2873 set breakpoint condition-evaluation
2874 show breakpoint condition-evaluation
2875 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2876 GDBserver ("target"). Default option "auto" chooses the most efficient
2878 This option can improve debugger efficiency depending on the speed of the
2882 Disable auto-loading globally.
2885 Show auto-loading setting of all kinds of auto-loaded files.
2887 set auto-load gdb-scripts on|off
2888 show auto-load gdb-scripts
2889 Control auto-loading of GDB canned sequences of commands files.
2891 set auto-load python-scripts on|off
2892 show auto-load python-scripts
2893 Control auto-loading of Python script files.
2895 set auto-load local-gdbinit on|off
2896 show auto-load local-gdbinit
2897 Control loading of init file (.gdbinit) from current directory.
2899 set auto-load libthread-db on|off
2900 show auto-load libthread-db
2901 Control auto-loading of inferior specific thread debugging shared library.
2903 set auto-load scripts-directory <dir1>[:<dir2>...]
2904 show auto-load scripts-directory
2905 Set a list of directories from which to load auto-loaded scripts.
2906 Automatically loaded Python scripts and GDB scripts are located in one
2907 of the directories listed by this option.
2908 The delimiter (':' above) may differ according to the host platform.
2910 set auto-load safe-path <dir1>[:<dir2>...]
2911 show auto-load safe-path
2912 Set a list of directories from which it is safe to auto-load files.
2913 The delimiter (':' above) may differ according to the host platform.
2915 set debug auto-load on|off
2916 show debug auto-load
2917 Control display of debugging info for auto-loading the files above.
2919 set dprintf-style gdb|call|agent
2921 Control the way in which a dynamic printf is performed; "gdb"
2922 requests a GDB printf command, while "call" causes dprintf to call a
2923 function in the inferior. "agent" requests that the target agent
2924 (such as GDBserver) do the printing.
2926 set dprintf-function <expr>
2927 show dprintf-function
2928 set dprintf-channel <expr>
2929 show dprintf-channel
2930 Set the function and optional first argument to the call when using
2931 the "call" style of dynamic printf.
2933 set disconnected-dprintf on|off
2934 show disconnected-dprintf
2935 Control whether agent-style dynamic printfs continue to be in effect
2936 after GDB disconnects.
2938 * New configure options
2940 --with-auto-load-dir
2941 Configure default value for the 'set auto-load scripts-directory'
2942 setting above. It defaults to '$debugdir:$datadir/auto-load',
2943 $debugdir representing global debugging info directories (available
2944 via 'show debug-file-directory') and $datadir representing GDB's data
2945 directory (available via 'show data-directory').
2947 --with-auto-load-safe-path
2948 Configure default value for the 'set auto-load safe-path' setting
2949 above. It defaults to the --with-auto-load-dir setting.
2951 --without-auto-load-safe-path
2952 Set 'set auto-load safe-path' to '/', effectively disabling this
2955 * New remote packets
2957 z0/z1 conditional breakpoints extension
2959 The z0/z1 breakpoint insertion packets have been extended to carry
2960 a list of conditional expressions over to the remote stub depending on the
2961 condition evaluation mode. The use of this extension can be controlled
2962 via the "set remote conditional-breakpoints-packet" command.
2966 Specify the signals which the remote stub may pass to the debugged
2967 program without GDB involvement.
2969 * New command line options
2971 --init-command=FILE, -ix Like --command, -x but execute it
2972 before loading inferior.
2973 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2974 execute it before loading inferior.
2976 *** Changes in GDB 7.4
2978 * GDB now handles ambiguous linespecs more consistently; the existing
2979 FILE:LINE support has been expanded to other types of linespecs. A
2980 breakpoint will now be set on all matching locations in all
2981 inferiors, and locations will be added or removed according to
2984 * GDB now allows you to skip uninteresting functions and files when
2985 stepping with the "skip function" and "skip file" commands.
2987 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2988 and "show remote hardware-watchpoint-length-limit". These allows to
2989 set or show the maximum length limit (in bytes) of a remote
2990 target hardware watchpoint.
2992 This allows e.g. to use "unlimited" hardware watchpoints with the
2993 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2994 watchpoints are slower than real hardware watchpoints but are
2995 significantly faster than gdb software watchpoints.
2999 ** The register_pretty_printer function in module gdb.printing now takes
3000 an optional `replace' argument. If True, the new printer replaces any
3003 ** The "maint set python print-stack on|off" command has been
3004 deprecated and will be deleted in GDB 7.5.
3005 A new command: "set python print-stack none|full|message" has
3006 replaced it. Additionally, the default for "print-stack" is
3007 now "message", which just prints the error message without
3010 ** A prompt substitution hook (prompt_hook) is now available to the
3013 ** A new Python module, gdb.prompt has been added to the GDB Python
3014 modules library. This module provides functionality for
3015 escape sequences in prompts (used by set/show
3016 extended-prompt). These escape sequences are replaced by their
3017 corresponding value.
3019 ** Python commands and convenience-functions located in
3020 'data-directory'/python/gdb/command and
3021 'data-directory'/python/gdb/function are now automatically loaded
3024 ** Blocks now provide four new attributes. global_block and
3025 static_block will return the global and static blocks
3026 respectively. is_static and is_global are boolean attributes
3027 that indicate if the block is one of those two types.
3029 ** Symbols now provide the "type" attribute, the type of the symbol.
3031 ** The "gdb.breakpoint" function has been deprecated in favor of
3034 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3035 of a function. This class is based on the "finish" command
3036 available in the CLI.
3038 ** Type objects for struct and union types now allow access to
3039 the fields using standard Python dictionary (mapping) methods.
3040 For example, "some_type['myfield']" now works, as does
3041 "some_type.items()".
3043 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3046 ** A new function, "deep_items" has been added to the gdb.types
3047 module in the GDB Python modules library. This function returns
3048 an iterator over the fields of a struct or union type. Unlike
3049 the standard Python "iteritems" method, it will recursively traverse
3050 any anonymous fields.
3054 ** "*stopped" events can report several new "reason"s, such as
3057 ** Breakpoint changes are now notified using new async records, like
3058 "=breakpoint-modified".
3060 ** New command -ada-task-info.
3062 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3063 $sdir specifies the default system locations of shared libraries.
3064 $pdir specifies the directory where the libpthread used by the application
3067 GDB no longer looks in $sdir and $pdir after it has searched the directories
3068 mentioned in libthread-db-search-path. If you want to search those
3069 directories, they must be specified in libthread-db-search-path.
3070 The default value of libthread-db-search-path on GNU/Linux and Solaris
3071 systems is now "$sdir:$pdir".
3073 $pdir is not supported by gdbserver, it is currently ignored.
3074 $sdir is supported by gdbserver.
3076 * New configure option --with-iconv-bin.
3077 When using the internationalization support like the one in the GNU C
3078 library, GDB will invoke the "iconv" program to get a list of supported
3079 character sets. If this program lives in a non-standard location, one can
3080 use this option to specify where to find it.
3082 * When natively debugging programs on PowerPC BookE processors running
3083 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3084 watchpoints, which specify a mask in addition to an address to watch.
3085 The mask specifies that some bits of an address (the bits which are
3086 reset in the mask) should be ignored when matching the address accessed
3087 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3088 section in the user manual for more details.
3090 * The new option --once causes GDBserver to stop listening for connections once
3091 the first connection is made. The listening port used by GDBserver will
3092 become available after that.
3094 * New commands "info macros" and "alias" have been added.
3096 * New function parameters suffix @entry specifies value of function parameter
3097 at the time the function got called. Entry values are available only since
3103 "!" is now an alias of the "shell" command.
3104 Note that no space is needed between "!" and SHELL COMMAND.
3108 watch EXPRESSION mask MASK_VALUE
3109 The watch command now supports the mask argument which allows creation
3110 of masked watchpoints, if the current architecture supports this feature.
3112 info auto-load-scripts [REGEXP]
3113 This command was formerly named "maintenance print section-scripts".
3114 It is now generally useful and is no longer a maintenance-only command.
3116 info macro [-all] [--] MACRO
3117 The info macro command has new options `-all' and `--'. The first for
3118 printing all definitions of a macro. The second for explicitly specifying
3119 the end of arguments and the beginning of the macro name in case the macro
3120 name starts with a hyphen.
3122 collect[/s] EXPRESSIONS
3123 The tracepoint collect command now takes an optional modifier "/s"
3124 that directs it to dereference pointer-to-character types and
3125 collect the bytes of memory up to a zero byte. The behavior is
3126 similar to what you see when you use the regular print command on a
3127 string. An optional integer following the "/s" sets a bound on the
3128 number of bytes that will be collected.
3131 The trace start command now interprets any supplied arguments as a
3132 note to be recorded with the trace run, with an effect similar to
3133 setting the variable trace-notes.
3136 The trace stop command now interprets any arguments as a note to be
3137 mentioned along with the tstatus report that the trace was stopped
3138 with a command. The effect is similar to setting the variable
3141 * Tracepoints can now be enabled and disabled at any time after a trace
3142 experiment has been started using the standard "enable" and "disable"
3143 commands. It is now possible to start a trace experiment with no enabled
3144 tracepoints; GDB will display a warning, but will allow the experiment to
3145 begin, assuming that tracepoints will be enabled as needed while the trace
3148 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3149 locations with 4-byte instructions, when they were previously
3150 limited to locations with instructions of 5 bytes or longer.
3154 set debug dwarf2-read
3155 show debug dwarf2-read
3156 Turns on or off display of debugging messages related to reading
3157 DWARF debug info. The default is off.
3159 set debug symtab-create
3160 show debug symtab-create
3161 Turns on or off display of debugging messages related to symbol table
3162 creation. The default is off.
3165 show extended-prompt
3166 Set the GDB prompt, and allow escape sequences to be inserted to
3167 display miscellaneous information (see 'help set extended-prompt'
3168 for the list of sequences). This prompt (and any information
3169 accessed through the escape sequences) is updated every time the
3170 prompt is displayed.
3172 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3173 show print entry-values
3174 Set printing of frame argument values at function entry. In some cases
3175 GDB can determine the value of function argument which was passed by the
3176 function caller, even if the value was modified inside the called function.
3178 set debug entry-values
3179 show debug entry-values
3180 Control display of debugging info for determining frame argument values at
3181 function entry and virtual tail call frames.
3183 set basenames-may-differ
3184 show basenames-may-differ
3185 Set whether a source file may have multiple base names.
3186 (A "base name" is the name of a file with the directory part removed.
3187 Example: The base name of "/home/user/hello.c" is "hello.c".)
3188 If set, GDB will canonicalize file names (e.g., expand symlinks)
3189 before comparing them. Canonicalization is an expensive operation,
3190 but it allows the same file be known by more than one base name.
3191 If not set (the default), all source files are assumed to have just
3192 one base name, and gdb will do file name comparisons more efficiently.
3198 Set a user name and notes for the current and any future trace runs.
3199 This is useful for long-running and/or disconnected traces, to
3200 inform others (or yourself) as to who is running the trace, supply
3201 contact information, or otherwise explain what is going on.
3203 set trace-stop-notes
3204 show trace-stop-notes
3205 Set a note attached to the trace run, that is displayed when the
3206 trace has been stopped by a tstop command. This is useful for
3207 instance as an explanation, if you are stopping a trace run that was
3208 started by someone else.
3210 * New remote packets
3214 Dynamically enable a tracepoint in a started trace experiment.
3218 Dynamically disable a tracepoint in a started trace experiment.
3222 Set the user and notes of the trace run.
3226 Query the current status of a tracepoint.
3230 Query the minimum length of instruction at which a fast tracepoint may
3233 * Dcache size (number of lines) and line-size are now runtime-configurable
3234 via "set dcache line" and "set dcache line-size" commands.
3238 Texas Instruments TMS320C6x tic6x-*-*
3242 Renesas RL78 rl78-*-elf
3244 *** Changes in GDB 7.3.1
3246 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3248 *** Changes in GDB 7.3
3250 * GDB has a new command: "thread find [REGEXP]".
3251 It finds the thread id whose name, target id, or thread extra info
3252 matches the given regular expression.
3254 * The "catch syscall" command now works on mips*-linux* targets.
3256 * The -data-disassemble MI command now supports modes 2 and 3 for
3257 dumping the instruction opcodes.
3259 * New command line options
3261 -data-directory DIR Specify DIR as the "data-directory".
3262 This is mostly for testing purposes.
3264 * The "maint set python auto-load on|off" command has been renamed to
3265 "set auto-load-scripts on|off".
3267 * GDB has a new command: "set directories".
3268 It is like the "dir" command except that it replaces the
3269 source path list instead of augmenting it.
3271 * GDB now understands thread names.
3273 On GNU/Linux, "info threads" will display the thread name as set by
3274 prctl or pthread_setname_np.
3276 There is also a new command, "thread name", which can be used to
3277 assign a name internally for GDB to display.
3280 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3281 has been integrated into GDB.
3285 ** The function gdb.Write now accepts an optional keyword 'stream'.
3286 This keyword, when provided, will direct the output to either
3287 stdout, stderr, or GDB's logging output.
3289 ** Parameters can now be be sub-classed in Python, and in particular
3290 you may implement the get_set_doc and get_show_doc functions.
3291 This improves how Parameter set/show documentation is processed
3292 and allows for more dynamic content.
3294 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3295 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3296 have an is_valid method.
3298 ** Breakpoints can now be sub-classed in Python, and in particular
3299 you may implement a 'stop' function that is executed each time
3300 the inferior reaches that breakpoint.
3302 ** New function gdb.lookup_global_symbol looks up a global symbol.
3304 ** GDB values in Python are now callable if the value represents a
3305 function. For example, if 'some_value' represents a function that
3306 takes two integer parameters and returns a value, you can call
3307 that function like so:
3309 result = some_value (10,20)
3311 ** Module gdb.types has been added.
3312 It contains a collection of utilities for working with gdb.Types objects:
3313 get_basic_type, has_field, make_enum_dict.
3315 ** Module gdb.printing has been added.
3316 It contains utilities for writing and registering pretty-printers.
3317 New classes: PrettyPrinter, SubPrettyPrinter,
3318 RegexpCollectionPrettyPrinter.
3319 New function: register_pretty_printer.
3321 ** New commands "info pretty-printers", "enable pretty-printer" and
3322 "disable pretty-printer" have been added.
3324 ** gdb.parameter("directories") is now available.
3326 ** New function gdb.newest_frame returns the newest frame in the
3329 ** The gdb.InferiorThread class has a new "name" attribute. This
3330 holds the thread's name.
3332 ** Python Support for Inferior events.
3333 Python scripts can add observers to be notified of events
3334 occurring in the process being debugged.
3335 The following events are currently supported:
3336 - gdb.events.cont Continue event.
3337 - gdb.events.exited Inferior exited event.
3338 - gdb.events.stop Signal received, and Breakpoint hit events.
3342 ** GDB now puts template parameters in scope when debugging in an
3343 instantiation. For example, if you have:
3345 template<int X> int func (void) { return X; }
3347 then if you step into func<5>, "print X" will show "5". This
3348 feature requires proper debuginfo support from the compiler; it
3349 was added to GCC 4.5.
3351 ** The motion commands "next", "finish", "until", and "advance" now
3352 work better when exceptions are thrown. In particular, GDB will
3353 no longer lose control of the inferior; instead, the GDB will
3354 stop the inferior at the point at which the exception is caught.
3355 This functionality requires a change in the exception handling
3356 code that was introduced in GCC 4.5.
3358 * GDB now follows GCC's rules on accessing volatile objects when
3359 reading or writing target state during expression evaluation.
3360 One notable difference to prior behavior is that "print x = 0"
3361 no longer generates a read of x; the value of the assignment is
3362 now always taken directly from the value being assigned.
3364 * GDB now has some support for using labels in the program's source in
3365 linespecs. For instance, you can use "advance label" to continue
3366 execution to a label.
3368 * GDB now has support for reading and writing a new .gdb_index
3369 section. This section holds a fast index of DWARF debugging
3370 information and can be used to greatly speed up GDB startup and
3371 operation. See the documentation for `save gdb-index' for details.
3373 * The "watch" command now accepts an optional "-location" argument.
3374 When used, this causes GDB to watch the memory referred to by the
3375 expression. Such a watchpoint is never deleted due to it going out
3378 * GDB now supports thread debugging of core dumps on GNU/Linux.
3380 GDB now activates thread debugging using the libthread_db library
3381 when debugging GNU/Linux core dumps, similarly to when debugging
3382 live processes. As a result, when debugging a core dump file, GDB
3383 is now able to display pthread_t ids of threads. For example, "info
3384 threads" shows the same output as when debugging the process when it
3385 was live. In earlier releases, you'd see something like this:
3388 * 1 LWP 6780 main () at main.c:10
3390 While now you see this:
3393 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3395 It is also now possible to inspect TLS variables when debugging core
3398 When debugging a core dump generated on a machine other than the one
3399 used to run GDB, you may need to point GDB at the correct
3400 libthread_db library with the "set libthread-db-search-path"
3401 command. See the user manual for more details on this command.
3403 * When natively debugging programs on PowerPC BookE processors running
3404 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3405 which stop execution of the inferior whenever it executes an instruction
3406 at any address within the specified range. See the "PowerPC Embedded"
3407 section in the user manual for more details.
3409 * New features in the GDB remote stub, GDBserver
3411 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3412 and i686 LynxOS (version 5.x).
3414 ** GDBserver is now supported on Blackfin Linux.
3416 * New native configurations
3418 ia64 HP-UX ia64-*-hpux*
3422 Analog Devices, Inc. Blackfin Processor bfin-*
3424 * Ada task switching is now supported on sparc-elf targets when
3425 debugging a program using the Ravenscar Profile. For more information,
3426 see the "Tasking Support when using the Ravenscar Profile" section
3427 in the GDB user manual.
3429 * Guile support was removed.
3431 * New features in the GNU simulator
3433 ** The --map-info flag lists all known core mappings.
3435 ** CFI flashes may be simulated via the "cfi" device.
3437 *** Changes in GDB 7.2
3439 * Shared library support for remote targets by default
3441 When GDB is configured for a generic, non-OS specific target, like
3442 for example, --target=arm-eabi or one of the many *-*-elf targets,
3443 GDB now queries remote stubs for loaded shared libraries using the
3444 `qXfer:libraries:read' packet. Previously, shared library support
3445 was always disabled for such configurations.
3449 ** Argument Dependent Lookup (ADL)
3451 In C++ ADL lookup directs function search to the namespaces of its
3452 arguments even if the namespace has not been imported.
3462 Here the compiler will search for `foo' in the namespace of 'b'
3463 and find A::foo. GDB now supports this. This construct is commonly
3464 used in the Standard Template Library for operators.
3466 ** Improved User Defined Operator Support
3468 In addition to member operators, GDB now supports lookup of operators
3469 defined in a namespace and imported with a `using' directive, operators
3470 defined in the global scope, operators imported implicitly from an
3471 anonymous namespace, and the ADL operators mentioned in the previous
3473 GDB now also supports proper overload resolution for all the previously
3474 mentioned flavors of operators.
3476 ** static const class members
3478 Printing of static const class members that are initialized in the
3479 class definition has been fixed.
3481 * Windows Thread Information Block access.
3483 On Windows targets, GDB now supports displaying the Windows Thread
3484 Information Block (TIB) structure. This structure is visible either
3485 by using the new command `info w32 thread-information-block' or, by
3486 dereferencing the new convenience variable named `$_tlb', a
3487 thread-specific pointer to the TIB. This feature is also supported
3488 when remote debugging using GDBserver.
3490 * Static tracepoints
3492 Static tracepoints are calls in the user program into a tracing
3493 library. One such library is a port of the LTTng kernel tracer to
3494 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3495 When debugging with GDBserver, GDB now supports combining the GDB
3496 tracepoint machinery with such libraries. For example: the user can
3497 use GDB to probe a static tracepoint marker (a call from the user
3498 program into the tracing library) with the new "strace" command (see
3499 "New commands" below). This creates a "static tracepoint" in the
3500 breakpoint list, that can be manipulated with the same feature set
3501 as fast and regular tracepoints. E.g., collect registers, local and
3502 global variables, collect trace state variables, and define
3503 tracepoint conditions. In addition, the user can collect extra
3504 static tracepoint marker specific data, by collecting the new
3505 $_sdata internal variable. When analyzing the trace buffer, you can
3506 inspect $_sdata like any other variable available to GDB. For more
3507 information, see the "Tracepoints" chapter in GDB user manual. New
3508 remote packets have been defined to support static tracepoints, see
3509 the "New remote packets" section below.
3511 * Better reconstruction of tracepoints after disconnected tracing
3513 GDB will attempt to download the original source form of tracepoint
3514 definitions when starting a trace run, and then will upload these
3515 upon reconnection to the target, resulting in a more accurate
3516 reconstruction of the tracepoints that are in use on the target.
3520 You can now exercise direct control over the ways that GDB can
3521 affect your program. For instance, you can disallow the setting of
3522 breakpoints, so that the program can run continuously (assuming
3523 non-stop mode). In addition, the "observer" variable is available
3524 to switch all of the different controls; in observer mode, GDB
3525 cannot affect the target's behavior at all, which is useful for
3526 tasks like diagnosing live systems in the field.
3528 * The new convenience variable $_thread holds the number of the
3531 * New remote packets
3535 Return the address of the Windows Thread Information Block of a given thread.
3539 In response to several of the tracepoint packets, the target may now
3540 also respond with a number of intermediate `qRelocInsn' request
3541 packets before the final result packet, to have GDB handle
3542 relocating an instruction to execute at a different address. This
3543 is particularly useful for stubs that support fast tracepoints. GDB
3544 reports support for this feature in the qSupported packet.
3548 List static tracepoint markers in the target program.
3552 List static tracepoint markers at a given address in the target
3555 qXfer:statictrace:read
3557 Read the static trace data collected (by a `collect $_sdata'
3558 tracepoint action). The remote stub reports support for this packet
3559 to gdb's qSupported query.
3563 Send the current settings of GDB's permission flags.
3567 Send part of the source (textual) form of a tracepoint definition,
3568 which includes location, conditional, and action list.
3570 * The source command now accepts a -s option to force searching for the
3571 script in the source search path even if the script name specifies
3574 * New features in the GDB remote stub, GDBserver
3576 - GDBserver now support tracepoints (including fast tracepoints, and
3577 static tracepoints). The feature is currently supported by the
3578 i386-linux and amd64-linux builds. See the "Tracepoints support
3579 in gdbserver" section in the manual for more information.
3581 GDBserver JIT compiles the tracepoint's conditional agent
3582 expression bytecode into native code whenever possible for low
3583 overhead dynamic tracepoints conditionals. For such tracepoints,
3584 an expression that examines program state is evaluated when the
3585 tracepoint is reached, in order to determine whether to capture
3586 trace data. If the condition is simple and false, processing the
3587 tracepoint finishes very quickly and no data is gathered.
3589 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3590 for static tracepoints support.
3592 - GDBserver now supports x86_64 Windows 64-bit debugging.
3594 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3595 it understands register description.
3597 * The --batch flag now disables pagination and queries.
3599 * X86 general purpose registers
3601 GDB now supports reading/writing byte, word and double-word x86
3602 general purpose registers directly. This means you can use, say,
3603 $ah or $ax to refer, respectively, to the byte register AH and
3604 16-bit word register AX that are actually portions of the 32-bit
3605 register EAX or 64-bit register RAX.
3607 * The `commands' command now accepts a range of breakpoints to modify.
3608 A plain `commands' following a command that creates multiple
3609 breakpoints affects all the breakpoints set by that command. This
3610 applies to breakpoints set by `rbreak', and also applies when a
3611 single `break' command creates multiple breakpoints (e.g.,
3612 breakpoints on overloaded c++ functions).
3614 * The `rbreak' command now accepts a filename specification as part of
3615 its argument, limiting the functions selected by the regex to those
3616 in the specified file.
3618 * Support for remote debugging Windows and SymbianOS shared libraries
3619 from Unix hosts has been improved. Non Windows GDB builds now can
3620 understand target reported file names that follow MS-DOS based file
3621 system semantics, such as file names that include drive letters and
3622 use the backslash character as directory separator. This makes it
3623 possible to transparently use the "set sysroot" and "set
3624 solib-search-path" on Unix hosts to point as host copies of the
3625 target's shared libraries. See the new command "set
3626 target-file-system-kind" described below, and the "Commands to
3627 specify files" section in the user manual for more information.
3631 eval template, expressions...
3632 Convert the values of one or more expressions under the control
3633 of the string template to a command line, and call it.
3635 set target-file-system-kind unix|dos-based|auto
3636 show target-file-system-kind
3637 Set or show the assumed file system kind for target reported file
3640 save breakpoints <filename>
3641 Save all current breakpoint definitions to a file suitable for use
3642 in a later debugging session. To read the saved breakpoint
3643 definitions, use the `source' command.
3645 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3648 info static-tracepoint-markers
3649 Display information about static tracepoint markers in the target.
3651 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3652 Define a static tracepoint by probing a marker at the given
3653 function, line, address, or marker ID.
3657 Enable and disable observer mode.
3659 set may-write-registers on|off
3660 set may-write-memory on|off
3661 set may-insert-breakpoints on|off
3662 set may-insert-tracepoints on|off
3663 set may-insert-fast-tracepoints on|off
3664 set may-interrupt on|off
3665 Set individual permissions for GDB effects on the target. Note that
3666 some of these settings can have undesirable or surprising
3667 consequences, particularly when changed in the middle of a session.
3668 For instance, disabling the writing of memory can prevent
3669 breakpoints from being inserted, cause single-stepping to fail, or
3670 even crash your program, if you disable after breakpoints have been
3671 inserted. However, GDB should not crash.
3673 set record memory-query on|off
3674 show record memory-query
3675 Control whether to stop the inferior if memory changes caused
3676 by an instruction cannot be recorded.
3681 The disassemble command now supports "start,+length" form of two arguments.
3685 ** GDB now provides a new directory location, called the python directory,
3686 where Python scripts written for GDB can be installed. The location
3687 of that directory is <data-directory>/python, where <data-directory>
3688 is the GDB data directory. For more details, see section `Scripting
3689 GDB using Python' in the manual.
3691 ** The GDB Python API now has access to breakpoints, symbols, symbol
3692 tables, program spaces, inferiors, threads and frame's code blocks.
3693 Additionally, GDB Parameters can now be created from the API, and
3694 manipulated via set/show in the CLI.
3696 ** New functions gdb.target_charset, gdb.target_wide_charset,
3697 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3699 ** New exception gdb.GdbError.
3701 ** Pretty-printers are now also looked up in the current program space.
3703 ** Pretty-printers can now be individually enabled and disabled.
3705 ** GDB now looks for names of Python scripts to auto-load in a
3706 special section named `.debug_gdb_scripts', in addition to looking
3707 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3709 * Tracepoint actions were unified with breakpoint commands. In particular,
3710 there are no longer differences in "info break" output for breakpoints and
3711 tracepoints and the "commands" command can be used for both tracepoints and
3712 regular breakpoints.
3716 ARM Symbian arm*-*-symbianelf*
3718 * D language support.
3719 GDB now supports debugging programs written in the D programming
3722 * GDB now supports the extended ptrace interface for PowerPC which is
3723 available since Linux kernel version 2.6.34. This automatically enables
3724 any hardware breakpoints and additional hardware watchpoints available in
3725 the processor. The old ptrace interface exposes just one hardware
3726 watchpoint and no hardware breakpoints.
3728 * GDB is now able to use the Data Value Compare (DVC) register available on
3729 embedded PowerPC processors to implement in hardware simple watchpoint
3730 conditions of the form:
3732 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3734 This works in native GDB running on Linux kernels with the extended ptrace
3735 interface mentioned above.
3737 *** Changes in GDB 7.1
3741 ** Namespace Support
3743 GDB now supports importing of namespaces in C++. This enables the
3744 user to inspect variables from imported namespaces. Support for
3745 namepace aliasing has also been added. So, if a namespace is
3746 aliased in the current scope (e.g. namepace C=A; ) the user can
3747 print variables using the alias (e.g. (gdb) print C::x).
3751 All known bugs relating to the printing of virtual base class were
3752 fixed. It is now possible to call overloaded static methods using a
3757 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3758 and reinterpret_cast<> are now handled by the C++ expression parser.
3762 Xilinx MicroBlaze microblaze-*-*
3767 Xilinx MicroBlaze microblaze
3770 * Multi-program debugging.
3772 GDB now has support for multi-program (a.k.a. multi-executable or
3773 multi-exec) debugging. This allows for debugging multiple inferiors
3774 simultaneously each running a different program under the same GDB
3775 session. See "Debugging Multiple Inferiors and Programs" in the
3776 manual for more information. This implied some user visible changes
3777 in the multi-inferior support. For example, "info inferiors" now
3778 lists inferiors that are not running yet or that have exited
3779 already. See also "New commands" and "New options" below.
3781 * New tracing features
3783 GDB's tracepoint facility now includes several new features:
3785 ** Trace state variables
3787 GDB tracepoints now include support for trace state variables, which
3788 are variables managed by the target agent during a tracing
3789 experiment. They are useful for tracepoints that trigger each
3790 other, so for instance one tracepoint can count hits in a variable,
3791 and then a second tracepoint has a condition that is true when the
3792 count reaches a particular value. Trace state variables share the
3793 $-syntax of GDB convenience variables, and can appear in both
3794 tracepoint actions and condition expressions. Use the "tvariable"
3795 command to create, and "info tvariables" to view; see "Trace State
3796 Variables" in the manual for more detail.
3800 GDB now includes an option for defining fast tracepoints, which
3801 targets may implement more efficiently, such as by installing a jump
3802 into the target agent rather than a trap instruction. The resulting
3803 speedup can be by two orders of magnitude or more, although the
3804 tradeoff is that some program locations on some target architectures
3805 might not allow fast tracepoint installation, for instance if the
3806 instruction to be replaced is shorter than the jump. To request a
3807 fast tracepoint, use the "ftrace" command, with syntax identical to
3808 the regular trace command.
3810 ** Disconnected tracing
3812 It is now possible to detach GDB from the target while it is running
3813 a trace experiment, then reconnect later to see how the experiment
3814 is going. In addition, a new variable disconnected-tracing lets you
3815 tell the target agent whether to continue running a trace if the
3816 connection is lost unexpectedly.
3820 GDB now has the ability to save the trace buffer into a file, and
3821 then use that file as a target, similarly to you can do with
3822 corefiles. You can select trace frames, print data that was
3823 collected in them, and use tstatus to display the state of the
3824 tracing run at the moment that it was saved. To create a trace
3825 file, use "tsave <filename>", and to use it, do "target tfile
3828 ** Circular trace buffer
3830 You can ask the target agent to handle the trace buffer as a
3831 circular buffer, discarding the oldest trace frames to make room for
3832 newer ones, by setting circular-trace-buffer to on. This feature may
3833 not be available for all target agents.
3838 The disassemble command, when invoked with two arguments, now requires
3839 the arguments to be comma-separated.
3842 The info variables command now displays variable definitions. Files
3843 which only declare a variable are not shown.
3846 The source command is now capable of sourcing Python scripts.
3847 This feature is dependent on the debugger being build with Python
3850 Related to this enhancement is also the introduction of a new command
3851 "set script-extension" (see below).
3853 * New commands (for set/show, see "New options" below)
3855 record save [<FILENAME>]
3856 Save a file (in core file format) containing the process record
3857 execution log for replay debugging at a later time.
3859 record restore <FILENAME>
3860 Restore the process record execution log that was saved at an
3861 earlier time, for replay debugging.
3863 add-inferior [-copies <N>] [-exec <FILENAME>]
3866 clone-inferior [-copies <N>] [ID]
3867 Make a new inferior ready to execute the same program another
3868 inferior has loaded.
3873 maint info program-spaces
3874 List the program spaces loaded into GDB.
3876 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3877 show remote interrupt-sequence
3878 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3879 as the sequence to the remote target in order to interrupt the execution.
3880 Ctrl-C is a default. Some system prefers BREAK which is high level of
3881 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3882 Magic SysRq g. It is BREAK signal and character 'g'.
3884 set remote interrupt-on-connect [on | off]
3885 show remote interrupt-on-connect
3886 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3887 remote target when gdb connects to it. This is needed when you debug
3890 set remotebreak [on | off]
3892 Deprecated. Use "set/show remote interrupt-sequence" instead.
3894 tvariable $NAME [ = EXP ]
3895 Create or modify a trace state variable.
3898 List trace state variables and their values.
3900 delete tvariable $NAME ...
3901 Delete one or more trace state variables.
3904 Evaluate the given expressions without collecting anything into the
3905 trace buffer. (Valid in tracepoint actions only.)
3907 ftrace FN / FILE:LINE / *ADDR
3908 Define a fast tracepoint at the given function, line, or address.
3910 * New expression syntax
3912 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3913 GDB now parses 0b101010 identically with 42.
3917 set follow-exec-mode new|same
3918 show follow-exec-mode
3919 Control whether GDB reuses the same inferior across an exec call or
3920 creates a new one. This is useful to be able to restart the old
3921 executable after the inferior having done an exec call.
3923 set default-collect EXPR, ...
3924 show default-collect
3925 Define a list of expressions to be collected at each tracepoint.
3926 This is a useful way to ensure essential items are not overlooked,
3927 such as registers or a critical global variable.
3929 set disconnected-tracing
3930 show disconnected-tracing
3931 If set to 1, the target is instructed to continue tracing if it
3932 loses its connection to GDB. If 0, the target is to stop tracing
3935 set circular-trace-buffer
3936 show circular-trace-buffer
3937 If set to on, the target is instructed to use a circular trace buffer
3938 and discard the oldest trace frames instead of stopping the trace due
3939 to a full trace buffer. If set to off, the trace stops when the buffer
3940 fills up. Some targets may not support this.
3942 set script-extension off|soft|strict
3943 show script-extension
3944 If set to "off", the debugger does not perform any script language
3945 recognition, and all sourced files are assumed to be GDB scripts.
3946 If set to "soft" (the default), files are sourced according to
3947 filename extension, falling back to GDB scripts if the first
3949 If set to "strict", files are sourced according to filename extension.
3951 set ada trust-PAD-over-XVS on|off
3952 show ada trust-PAD-over-XVS
3953 If off, activate a workaround against a bug in the debugging information
3954 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3955 the GCC sources for more information about the GNAT encoding and
3956 PAD types in particular). It is always safe to set this option to
3957 off, but this introduces a slight performance penalty. The default
3960 * Python API Improvements
3962 ** GDB provides the new class gdb.LazyString. This is useful in
3963 some pretty-printing cases. The new method gdb.Value.lazy_string
3964 provides a simple way to create objects of this type.
3966 ** The fields returned by gdb.Type.fields now have an
3967 `is_base_class' attribute.
3969 ** The new method gdb.Type.range returns the range of an array type.
3971 ** The new method gdb.parse_and_eval can be used to parse and
3972 evaluate an expression.
3974 * New remote packets
3977 Define a trace state variable.
3980 Get the current value of a trace state variable.
3983 Set desired tracing behavior upon disconnection.
3986 Set the trace buffer to be linear or circular.
3989 Get data about the tracepoints currently in use.
3993 Process record now works correctly with hardware watchpoints.
3995 Multiple bug fixes have been made to the mips-irix port, making it
3996 much more reliable. In particular:
3997 - Debugging threaded applications is now possible again. Previously,
3998 GDB would hang while starting the program, or while waiting for
3999 the program to stop at a breakpoint.
4000 - Attaching to a running process no longer hangs.
4001 - An error occurring while loading a core file has been fixed.
4002 - Changing the value of the PC register now works again. This fixes
4003 problems observed when using the "jump" command, or when calling
4004 a function from GDB, or even when assigning a new value to $pc.
4005 - With the "finish" and "return" commands, the return value for functions
4006 returning a small array is now correctly printed.
4007 - It is now possible to break on shared library code which gets executed
4008 during a shared library init phase (code executed while executing
4009 their .init section). Previously, the breakpoint would have no effect.
4010 - GDB is now able to backtrace through the signal handler for
4011 non-threaded programs.
4013 PIE (Position Independent Executable) programs debugging is now supported.
4014 This includes debugging execution of PIC (Position Independent Code) shared
4015 libraries although for that, it should be possible to run such libraries as an
4018 *** Changes in GDB 7.0
4020 * GDB now has an interface for JIT compilation. Applications that
4021 dynamically generate code can create symbol files in memory and register
4022 them with GDB. For users, the feature should work transparently, and
4023 for JIT developers, the interface is documented in the GDB manual in the
4024 "JIT Compilation Interface" chapter.
4026 * Tracepoints may now be conditional. The syntax is as for
4027 breakpoints; either an "if" clause appended to the "trace" command,
4028 or the "condition" command is available. GDB sends the condition to
4029 the target for evaluation using the same bytecode format as is used
4030 for tracepoint actions.
4032 * The disassemble command now supports: an optional /r modifier, print the
4033 raw instructions in hex as well as in symbolic form, and an optional /m
4034 modifier to print mixed source+assembly.
4036 * Process record and replay
4038 In a architecture environment that supports ``process record and
4039 replay'', ``process record and replay'' target can record a log of
4040 the process execution, and replay it with both forward and reverse
4043 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4044 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4045 set execution-direction {forward|reverse}, for targets that support
4048 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4049 feature is available with a native GDB running on kernel version
4052 * GDB now has support for multi-byte and wide character sets on the
4053 target. Strings whose character type is wchar_t, char16_t, or
4054 char32_t are now correctly printed. GDB supports wide- and unicode-
4055 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4056 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4057 `printf'. This feature requires iconv to work properly; if your
4058 system does not have a working iconv, GDB can use GNU libiconv. See
4059 the installation instructions for more information.
4061 * GDB now supports automatic retrieval of shared library files from
4062 remote targets. To use this feature, specify a system root that begins
4063 with the `remote:' prefix, either via the `set sysroot' command or via
4064 the `--with-sysroot' configure-time option.
4066 * "info sharedlibrary" now takes an optional regex of libraries to show,
4067 and it now reports if a shared library has no debugging information.
4069 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4070 now complete on file names.
4072 * When completing in expressions, gdb will attempt to limit
4073 completions to allowable structure or union fields, where appropriate.
4074 For instance, consider:
4076 # struct example { int f1; double f2; };
4077 # struct example variable;
4080 If the user types TAB at the end of this command line, the available
4081 completions will be "f1" and "f2".
4083 * Inlined functions are now supported. They show up in backtraces, and
4084 the "step", "next", and "finish" commands handle them automatically.
4086 * GDB now supports the token-splicing (##) and stringification (#)
4087 operators when expanding macros. It also supports variable-arity
4090 * GDB now supports inspecting extra signal information, exported by
4091 the new $_siginfo convenience variable. The feature is currently
4092 implemented on linux ARM, i386 and amd64.
4094 * GDB can now display the VFP floating point registers and NEON vector
4095 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4096 can provide these registers (requires Linux 2.6.30 or later). Remote
4097 and simulator targets may also provide them.
4099 * New remote packets
4102 Search memory for a sequence of bytes.
4105 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4106 operation over reliable transport links. Use of this packet is
4107 controlled by the `set remote noack-packet' command.
4110 Kill the process with the specified process ID. Use this in preference
4111 to `k' when multiprocess protocol extensions are supported.
4114 Obtains additional operating system information
4118 Read or write additional signal information.
4120 * Removed remote protocol undocumented extension
4122 An undocumented extension to the remote protocol's `S' stop reply
4123 packet that permited the stub to pass a process id was removed.
4124 Remote servers should use the `T' stop reply packet instead.
4126 * GDB now supports multiple function calling conventions according to the
4127 DWARF-2 DW_AT_calling_convention function attribute.
4129 * The SH target utilizes the aforementioned change to distinguish between gcc
4130 and Renesas calling convention. It also adds the new CLI commands
4131 `set/show sh calling-convention'.
4133 * GDB can now read compressed debug sections, as produced by GNU gold
4134 with the --compress-debug-sections=zlib flag.
4136 * 64-bit core files are now supported on AIX.
4138 * Thread switching is now supported on Tru64.
4140 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4141 which will be allocated using malloc later in program execution.
4143 * The qXfer:libraries:read remote procotol packet now allows passing a
4144 list of section offsets.
4146 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4147 conditions handling signals delivered during attach or thread creation
4148 have also been fixed.
4150 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4151 From the user's standpoint, all unqualified instances of True and False
4152 are treated as the standard definitions, regardless of context.
4154 * GDB now parses C++ symbol and type names more flexibly. For
4157 template<typename T> class C { };
4160 GDB will now correctly handle all of:
4162 ptype C<char const *>
4163 ptype C<char const*>
4164 ptype C<const char *>
4165 ptype C<const char*>
4167 * New features in the GDB remote stub, gdbserver
4169 - The "--wrapper" command-line argument tells gdbserver to use a
4170 wrapper program to launch programs for debugging.
4172 - On PowerPC and S/390 targets, it is now possible to use a single
4173 gdbserver executable to debug both 32-bit and 64-bit programs.
4174 (This requires gdbserver itself to be built as a 64-bit executable.)
4176 - gdbserver uses the new noack protocol mode for TCP connections to
4177 reduce communications latency, if also supported and enabled in GDB.
4179 - Support for the sparc64-linux-gnu target is now included in
4182 - The amd64-linux build of gdbserver now supports debugging both
4183 32-bit and 64-bit programs.
4185 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4186 now support hardware watchpoints, and will use them automatically
4191 GDB now has support for scripting using Python. Whether this is
4192 available is determined at configure time.
4194 New GDB commands can now be written in Python.
4196 * Ada tasking support
4198 Ada tasks can now be inspected in GDB. The following commands have
4202 Print the list of Ada tasks.
4204 Print detailed information about task number N.
4206 Print the task number of the current task.
4208 Switch the context of debugging to task number N.
4210 * Support for user-defined prefixed commands. The "define" command can
4211 add new commands to existing prefixes, e.g. "target".
4213 * Multi-inferior, multi-process debugging.
4215 GDB now has generalized support for multi-inferior debugging. See
4216 "Debugging Multiple Inferiors" in the manual for more information.
4217 Although availability still depends on target support, the command
4218 set is more uniform now. The GNU/Linux specific multi-forks support
4219 has been migrated to this new framework. This implied some user
4220 visible changes; see "New commands" and also "Removed commands"
4223 * Target descriptions can now describe the target OS ABI. See the
4224 "Target Description Format" section in the user manual for more
4227 * Target descriptions can now describe "compatible" architectures
4228 to indicate that the target can execute applications for a different
4229 architecture in addition to those for the main target architecture.
4230 See the "Target Description Format" section in the user manual for
4233 * Multi-architecture debugging.
4235 GDB now includes general supports for debugging applications on
4236 hybrid systems that use more than one single processor architecture
4237 at the same time. Each such hybrid architecture still requires
4238 specific support to be added. The only hybrid architecture supported
4239 in this version of GDB is the Cell Broadband Engine.
4241 * GDB now supports integrated debugging of Cell/B.E. applications that
4242 use both the PPU and SPU architectures. To enable support for hybrid
4243 Cell/B.E. debugging, you need to configure GDB to support both the
4244 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4245 --enable-targets configure option.
4247 * Non-stop mode debugging.
4249 For some targets, GDB now supports an optional mode of operation in
4250 which you can examine stopped threads while other threads continue
4251 to execute freely. This is referred to as non-stop mode, with the
4252 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4253 section in the user manual for more information.
4255 To be able to support remote non-stop debugging, a remote stub needs
4256 to implement the non-stop mode remote protocol extensions, as
4257 described in the "Remote Non-Stop" section of the user manual. The
4258 GDB remote stub, gdbserver, has been adjusted to support these
4259 extensions on linux targets.
4261 * New commands (for set/show, see "New options" below)
4263 catch syscall [NAME(S) | NUMBER(S)]
4264 Catch system calls. Arguments, which should be names of system
4265 calls or their numbers, mean catch only those syscalls. Without
4266 arguments, every syscall will be caught. When the inferior issues
4267 any of the specified syscalls, GDB will stop and announce the system
4268 call, both when it is called and when its call returns. This
4269 feature is currently available with a native GDB running on the
4270 Linux Kernel, under the following architectures: x86, x86_64,
4271 PowerPC and PowerPC64.
4273 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4275 Search memory for a sequence of bytes.
4277 maint set python print-stack
4278 maint show python print-stack
4279 Show a stack trace when an error is encountered in a Python script.
4282 Invoke CODE by passing it to the Python interpreter.
4287 These allow macros to be defined, undefined, and listed
4291 Show operating system information about processes.
4294 List the inferiors currently under GDB's control.
4297 Switch focus to inferior number NUM.
4300 Detach from inferior number NUM.
4303 Kill inferior number NUM.
4307 set spu stop-on-load
4308 show spu stop-on-load
4309 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4311 set spu auto-flush-cache
4312 show spu auto-flush-cache
4313 Control whether to automatically flush the software-managed cache
4314 during Cell/B.E. debugging.
4316 set sh calling-convention
4317 show sh calling-convention
4318 Control the calling convention used when calling SH target functions.
4321 show debug timestamp
4322 Control display of timestamps with GDB debugging output.
4324 set disassemble-next-line
4325 show disassemble-next-line
4326 Control display of disassembled source lines or instructions when
4329 set remote noack-packet
4330 show remote noack-packet
4331 Set/show the use of remote protocol QStartNoAckMode packet. See above
4332 under "New remote packets."
4334 set remote query-attached-packet
4335 show remote query-attached-packet
4336 Control use of remote protocol `qAttached' (query-attached) packet.
4338 set remote read-siginfo-object
4339 show remote read-siginfo-object
4340 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4343 set remote write-siginfo-object
4344 show remote write-siginfo-object
4345 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4348 set remote reverse-continue
4349 show remote reverse-continue
4350 Control use of remote protocol 'bc' (reverse-continue) packet.
4352 set remote reverse-step
4353 show remote reverse-step
4354 Control use of remote protocol 'bs' (reverse-step) packet.
4356 set displaced-stepping
4357 show displaced-stepping
4358 Control displaced stepping mode. Displaced stepping is a way to
4359 single-step over breakpoints without removing them from the debuggee.
4360 Also known as "out-of-line single-stepping".
4363 show debug displaced
4364 Control display of debugging info for displaced stepping.
4366 maint set internal-error
4367 maint show internal-error
4368 Control what GDB does when an internal error is detected.
4370 maint set internal-warning
4371 maint show internal-warning
4372 Control what GDB does when an internal warning is detected.
4377 Use a wrapper program to launch programs for debugging.
4379 set multiple-symbols (all|ask|cancel)
4380 show multiple-symbols
4381 The value of this variable can be changed to adjust the debugger behavior
4382 when an expression or a breakpoint location contains an ambiguous symbol
4383 name (an overloaded function name, for instance).
4385 set breakpoint always-inserted
4386 show breakpoint always-inserted
4387 Keep breakpoints always inserted in the target, as opposed to inserting
4388 them when resuming the target, and removing them when the target stops.
4389 This option can improve debugger performance on slow remote targets.
4391 set arm fallback-mode (arm|thumb|auto)
4392 show arm fallback-mode
4393 set arm force-mode (arm|thumb|auto)
4395 These commands control how ARM GDB determines whether instructions
4396 are ARM or Thumb. The default for both settings is auto, which uses
4397 the current CPSR value for instructions without symbols; previous
4398 versions of GDB behaved as if "set arm fallback-mode arm".
4400 set disable-randomization
4401 show disable-randomization
4402 Standalone programs run with the virtual address space randomization enabled
4403 by default on some platforms. This option keeps the addresses stable across
4404 multiple debugging sessions.
4408 Control whether other threads are stopped or not when some thread hits
4413 Requests that asynchronous execution is enabled in the target, if available.
4414 In this case, it's possible to resume target in the background, and interact
4415 with GDB while the target is running. "show target-async" displays the
4416 current state of asynchronous execution of the target.
4418 set target-wide-charset
4419 show target-wide-charset
4420 The target-wide-charset is the name of the character set that GDB
4421 uses when printing characters whose type is wchar_t.
4423 set tcp auto-retry (on|off)
4425 set tcp connect-timeout
4426 show tcp connect-timeout
4427 These commands allow GDB to retry failed TCP connections to a remote stub
4428 with a specified timeout period; this is useful if the stub is launched
4429 in parallel with GDB but may not be ready to accept connections immediately.
4431 set libthread-db-search-path
4432 show libthread-db-search-path
4433 Control list of directories which GDB will search for appropriate
4436 set schedule-multiple (on|off)
4437 show schedule-multiple
4438 Allow GDB to resume all threads of all processes or only threads of
4439 the current process.
4443 Use more aggressive caching for accesses to the stack. This improves
4444 performance of remote debugging (particularly backtraces) without
4445 affecting correctness.
4447 set interactive-mode (on|off|auto)
4448 show interactive-mode
4449 Control whether GDB runs in interactive mode (on) or not (off).
4450 When in interactive mode, GDB waits for the user to answer all
4451 queries. Otherwise, GDB does not wait and assumes the default
4452 answer. When set to auto (the default), GDB determines which
4453 mode to use based on the stdin settings.
4458 For program forks, this is replaced by the new more generic `info
4459 inferiors' command. To list checkpoints, you can still use the
4460 `info checkpoints' command, which was an alias for the `info forks'
4464 Replaced by the new `inferior' command. To switch between
4465 checkpoints, you can still use the `restart' command, which was an
4466 alias for the `fork' command.
4469 This is removed, since some targets don't have a notion of
4470 processes. To switch between processes, you can still use the
4471 `inferior' command using GDB's own inferior number.
4474 For program forks, this is replaced by the new more generic `kill
4475 inferior' command. To delete a checkpoint, you can still use the
4476 `delete checkpoint' command, which was an alias for the `delete
4480 For program forks, this is replaced by the new more generic `detach
4481 inferior' command. To detach a checkpoint, you can still use the
4482 `detach checkpoint' command, which was an alias for the `detach
4485 * New native configurations
4487 x86/x86_64 Darwin i[34567]86-*-darwin*
4489 x86_64 MinGW x86_64-*-mingw*
4493 Lattice Mico32 lm32-*
4494 x86 DICOS i[34567]86-*-dicos*
4495 x86_64 DICOS x86_64-*-dicos*
4498 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4499 (mingw32ce) debugging.
4505 These commands were actually not implemented on any target.
4507 *** Changes in GDB 6.8
4509 * New native configurations
4511 NetBSD/hppa hppa*-*netbsd*
4512 Xtensa GNU/Linux xtensa*-*-linux*
4516 NetBSD/hppa hppa*-*-netbsd*
4517 Xtensa GNU/Lunux xtensa*-*-linux*
4519 * Change in command line behavior -- corefiles vs. process ids.
4521 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4522 attaching to process NUMBER fails, GDB no longer attempts to open a
4523 core file named NUMBER. Attaching to a program using the -c option
4524 is no longer supported. Instead, use the '-p' or '--pid' options.
4526 * GDB can now be built as a native debugger for debugging Windows x86
4527 (mingw32) Portable Executable (PE) programs.
4529 * Pending breakpoints no longer change their number when their address
4532 * GDB now supports breakpoints with multiple locations,
4533 including breakpoints on C++ constructors, inside C++ templates,
4534 and in inlined functions.
4536 * GDB's ability to debug optimized code has been improved. GDB more
4537 accurately identifies function bodies and lexical blocks that occupy
4538 more than one contiguous range of addresses.
4540 * Target descriptions can now describe registers for PowerPC.
4542 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4543 registers on PowerPC targets.
4545 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4546 targets even when the libthread_db library is not available.
4548 * The GDB remote stub, gdbserver, now supports the new file transfer
4549 commands (remote put, remote get, and remote delete).
4551 * The GDB remote stub, gdbserver, now supports run and attach in
4552 extended-remote mode.
4554 * hppa*64*-*-hpux11* target broken
4555 The debugger is unable to start a program and fails with the following
4556 error: "Error trying to get information about dynamic linker".
4557 The gdb-6.7 release is also affected.
4559 * GDB now supports the --enable-targets= configure option to allow
4560 building a single GDB executable that supports multiple remote
4561 target architectures.
4563 * GDB now supports debugging C and C++ programs which use the
4564 Decimal Floating Point extension. In addition, the PowerPC target
4565 now has a set of pseudo-registers to inspect decimal float values
4566 stored in two consecutive float registers.
4568 * The -break-insert MI command can optionally create pending
4571 * Improved support for debugging Ada
4572 Many improvements to the Ada language support have been made. These
4574 - Better support for Ada2005 interface types
4575 - Improved handling of arrays and slices in general
4576 - Better support for Taft-amendment types
4577 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4579 - Improved command completion in Ada
4582 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4587 set print frame-arguments (all|scalars|none)
4588 show print frame-arguments
4589 The value of this variable can be changed to control which argument
4590 values should be printed by the debugger when displaying a frame.
4595 Transfer files to and from a remote target, and delete remote files.
4602 Transfer files to and from a remote target, and delete remote files.
4604 * New remote packets
4611 Open, close, read, write, and delete files on the remote system.
4614 Attach to an existing process on the remote system, in extended-remote
4618 Run a new process on the remote system, in extended-remote mode.
4620 *** Changes in GDB 6.7
4622 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4623 bfd, libiberty and opcodes, as revealed by static analysis donated by
4624 Coverity, Inc. (http://scan.coverity.com).
4626 * When looking up multiply-defined global symbols, GDB will now prefer the
4627 symbol definition in the current shared library if it was built using the
4628 -Bsymbolic linker option.
4630 * When the Text User Interface (TUI) is not configured, GDB will now
4631 recognize the -tui command-line option and print a message that the TUI
4634 * The GDB remote stub, gdbserver, now has lower overhead for high
4635 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4637 * GDB for MIPS targets now autodetects whether a remote target provides
4638 32-bit or 64-bit register values.
4640 * Support for C++ member pointers has been improved.
4642 * GDB now understands XML target descriptions, which specify the
4643 target's overall architecture. GDB can read a description from
4644 a local file or over the remote serial protocol.
4646 * Vectors of single-byte data use a new integer type which is not
4647 automatically displayed as character or string data.
4649 * The /s format now works with the print command. It displays
4650 arrays of single-byte integers and pointers to single-byte integers
4653 * Target descriptions can now describe target-specific registers,
4654 for architectures which have implemented the support (currently
4655 only ARM, M68K, and MIPS).
4657 * GDB and the GDB remote stub, gdbserver, now support the XScale
4660 * The GDB remote stub, gdbserver, has been updated to support
4661 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4662 has been rewritten to use the standard GDB remote protocol.
4664 * GDB can now step into C++ functions which are called through thunks.
4666 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4668 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4669 layout. It also supports a TextSeg= and DataSeg= response when only
4670 segment base addresses (rather than offsets) are available.
4672 * The /i format now outputs any trailing branch delay slot instructions
4673 immediately following the last instruction within the count specified.
4675 * The GDB remote protocol "T" stop reply packet now supports a
4676 "library" response. Combined with the new "qXfer:libraries:read"
4677 packet, this response allows GDB to debug shared libraries on targets
4678 where the operating system manages the list of loaded libraries (e.g.
4679 Windows and SymbianOS).
4681 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4682 (DLLs) on Windows and Windows CE targets.
4684 * GDB now supports a faster verification that a .debug file matches its binary
4685 according to its build-id signature, if the signature is present.
4691 Enable or disable hardware flow control (RTS/CTS) on the serial port
4692 when debugging using remote targets.
4694 set mem inaccessible-by-default
4695 show mem inaccessible-by-default
4696 If the target supplies a memory map, for instance via the remote
4697 protocol's "qXfer:memory-map:read" packet, setting this variable
4698 prevents GDB from accessing memory outside the memory map. This
4699 is useful for targets with memory mapped registers or which react
4700 badly to accesses of unmapped address space.
4702 set breakpoint auto-hw
4703 show breakpoint auto-hw
4704 If the target supplies a memory map, for instance via the remote
4705 protocol's "qXfer:memory-map:read" packet, setting this variable
4706 lets GDB use hardware breakpoints automatically for memory regions
4707 where it can not use software breakpoints. This covers both the
4708 "break" command and internal breakpoints used for other commands
4709 including "next" and "finish".
4712 catch exception unhandled
4713 Stop the program execution when Ada exceptions are raised.
4716 Stop the program execution when an Ada assertion failed.
4720 Set an alternate system root for target files. This is a more
4721 general version of "set solib-absolute-prefix", which is now
4722 an alias to "set sysroot".
4725 Provide extended SPU facility status information. This set of
4726 commands is available only when debugging the Cell/B.E. SPU
4729 * New native configurations
4731 OpenBSD/sh sh*-*openbsd*
4734 unset tdesc filename
4736 Use the specified local file as an XML target description, and do
4737 not query the target for its built-in description.
4741 OpenBSD/sh sh*-*-openbsd*
4742 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4743 Toshiba Media Processor mep-elf
4745 * New remote packets
4748 Ignore the specified signals; pass them directly to the debugged program
4749 without stopping other threads or reporting them to GDB.
4751 qXfer:features:read:
4752 Read an XML target description from the target, which describes its
4757 Read or write contents of an spufs file on the target system. These
4758 packets are available only on the Cell/B.E. SPU architecture.
4760 qXfer:libraries:read:
4761 Report the loaded shared libraries. Combined with new "T" packet
4762 response, this packet allows GDB to debug shared libraries on
4763 targets where the operating system manages the list of loaded
4764 libraries (e.g. Windows and SymbianOS).
4768 Support for these obsolete configurations has been removed.
4776 i[34567]86-*-lynxos*
4777 i[34567]86-*-netware*
4778 i[34567]86-*-sco3.2v5*
4779 i[34567]86-*-sco3.2v4*
4781 i[34567]86-*-sysv4.2*
4784 i[34567]86-*-unixware2*
4785 i[34567]86-*-unixware*
4794 * Other removed features
4801 Various m68k-only ROM monitors.
4808 Various Renesas ROM monitors and debugging interfaces for SH and
4813 Support for a Macraigor serial interface to on-chip debugging.
4814 GDB does not directly support the newer parallel or USB
4819 A debug information format. The predecessor to DWARF 2 and
4820 DWARF 3, which are still supported.
4822 Support for the HP aCC compiler on HP-UX/PA-RISC
4824 SOM-encapsulated symbolic debugging information, automatic
4825 invocation of pxdb, and the aCC custom C++ ABI. This does not
4826 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4827 with aCC can still be debugged on an assembly level.
4829 MIPS ".pdr" sections
4831 A MIPS-specific format used to describe stack frame layout
4832 in debugging information.
4836 GDB could work with an older version of Guile to debug
4837 the interpreter and Scheme programs running in it.
4839 set mips stack-arg-size
4840 set mips saved-gpreg-size
4842 Use "set mips abi" to control parameter passing for MIPS.
4844 *** Changes in GDB 6.6
4849 Cell Broadband Engine SPU spu-elf
4851 * GDB can now be configured as a cross-debugger targeting native Windows
4852 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4853 running on a Windows system over TCP/IP to debug Windows programs.
4855 * The GDB remote stub, gdbserver, has been updated to support Windows and
4856 Cygwin debugging. Both single-threaded and multi-threaded programs are
4859 * The "set trust-readonly-sections" command works again. This command was
4860 broken in GDB 6.3, 6.4, and 6.5.
4862 * The "load" command now supports writing to flash memory, if the remote
4863 stub provides the required support.
4865 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4866 longer requires symbolic debug information (e.g. DWARF-2).
4871 unset substitute-path
4872 show substitute-path
4873 Manage a list of substitution rules that GDB uses to rewrite the name
4874 of the directories where the sources are located. This can be useful
4875 for instance when the sources were moved to a different location
4876 between compilation and debugging.
4880 Print each CLI command as it is executed. Each command is prefixed with
4881 a number of `+' symbols representing the nesting depth.
4882 The source command now has a `-v' option to enable the same feature.
4886 The ARM Demon monitor support (RDP protocol, "target rdp").
4888 Kernel Object Display, an embedded debugging feature which only worked with
4889 an obsolete version of Cisco IOS.
4891 The 'set download-write-size' and 'show download-write-size' commands.
4893 * New remote packets
4896 Tell a stub about GDB client features, and request remote target features.
4897 The first feature implemented is PacketSize, which allows the target to
4898 specify the size of packets it can handle - to minimize the number of
4899 packets required and improve performance when connected to a remote
4903 Fetch an OS auxilliary vector from the remote stub. This packet is a
4904 more efficient replacement for qPart:auxv:read.
4906 qXfer:memory-map:read:
4907 Fetch a memory map from the remote stub, including information about
4908 RAM, ROM, and flash memory devices.
4913 Erase and program a flash memory device.
4915 * Removed remote packets
4918 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4919 used it, and only gdbserver implemented it.
4921 *** Changes in GDB 6.5
4925 Renesas M32C/M16C m32c-elf
4927 Morpho Technologies ms1 ms1-elf
4931 init-if-undefined Initialize a convenience variable, but
4932 only if it doesn't already have a value.
4934 The following commands are presently only implemented for native GNU/Linux:
4936 checkpoint Save a snapshot of the program state.
4938 restart <n> Return the program state to a
4939 previously saved state.
4941 info checkpoints List currently saved checkpoints.
4943 delete-checkpoint <n> Delete a previously saved checkpoint.
4945 set|show detach-on-fork Tell gdb whether to detach from a newly
4946 forked process, or to keep debugging it.
4948 info forks List forks of the user program that
4949 are available to be debugged.
4951 fork <n> Switch to debugging one of several
4952 forks of the user program that are
4953 available to be debugged.
4955 delete-fork <n> Delete a fork from the list of forks
4956 that are available to be debugged (and
4957 kill the forked process).
4959 detach-fork <n> Delete a fork from the list of forks
4960 that are available to be debugged (and
4961 allow the process to continue).
4965 Morpho Technologies ms2 ms1-elf
4967 * Improved Windows host support
4969 GDB now builds as a cross debugger hosted on i686-mingw32, including
4970 native console support, and remote communications using either
4971 network sockets or serial ports.
4973 * Improved Modula-2 language support
4975 GDB can now print most types in the Modula-2 syntax. This includes:
4976 basic types, set types, record types, enumerated types, range types,
4977 pointer types and ARRAY types. Procedure var parameters are correctly
4978 printed and hexadecimal addresses and character constants are also
4979 written in the Modula-2 syntax. Best results can be obtained by using
4980 GNU Modula-2 together with the -gdwarf-2 command line option.
4984 The ARM rdi-share module.
4986 The Netware NLM debug server.
4988 *** Changes in GDB 6.4
4990 * New native configurations
4992 OpenBSD/arm arm*-*-openbsd*
4993 OpenBSD/mips64 mips64-*-openbsd*
4997 Morpho Technologies ms1 ms1-elf
4999 * New command line options
5001 --batch-silent As for --batch, but totally silent.
5002 --return-child-result The debugger will exist with the same value
5003 the child (debugged) program exited with.
5004 --eval-command COMMAND, -ex COMMAND
5005 Execute a single GDB CLI command. This may be
5006 specified multiple times and in conjunction
5007 with the --command (-x) option.
5009 * Deprecated commands removed
5011 The following commands, that were deprecated in 2000, have been
5015 set|show arm disassembly-flavor set|show arm disassembler
5016 othernames set arm disassembler
5017 set|show remotedebug set|show debug remote
5018 set|show archdebug set|show debug arch
5019 set|show eventdebug set|show debug event
5022 * New BSD user-level threads support
5024 It is now possible to debug programs using the user-level threads
5025 library on OpenBSD and FreeBSD. Currently supported (target)
5028 FreeBSD/amd64 x86_64-*-freebsd*
5029 FreeBSD/i386 i386-*-freebsd*
5030 OpenBSD/i386 i386-*-openbsd*
5032 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5033 are not yet supported.
5035 * New support for Matsushita MN10300 w/sim added
5036 (Work in progress). mn10300-elf.
5038 * REMOVED configurations and files
5040 VxWorks and the XDR protocol *-*-vxworks
5041 Motorola MCORE mcore-*-*
5042 National Semiconductor NS32000 ns32k-*-*
5044 * New "set print array-indexes" command
5046 After turning this setting "on", GDB prints the index of each element
5047 when displaying arrays. The default is "off" to preserve the previous
5050 * VAX floating point support
5052 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5054 * User-defined command support
5056 In addition to using $arg0..$arg9 for argument passing, it is now possible
5057 to use $argc to determine now many arguments have been passed. See the
5058 section on user-defined commands in the user manual for more information.
5060 *** Changes in GDB 6.3:
5062 * New command line option
5064 GDB now accepts -l followed by a number to set the timeout for remote
5067 * GDB works with GCC -feliminate-dwarf2-dups
5069 GDB now supports a more compact representation of DWARF-2 debug
5070 information using DW_FORM_ref_addr references. These are produced
5071 by GCC with the option -feliminate-dwarf2-dups and also by some
5072 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5073 to use -feliminate-dwarf2-dups.
5075 * Internationalization
5077 When supported by the host system, GDB will be built with
5078 internationalization (libintl). The task of marking up the sources is
5079 continued, we're looking forward to our first translation.
5083 Initial support for debugging programs compiled with the GNAT
5084 implementation of the Ada programming language has been integrated
5085 into GDB. In this release, support is limited to expression evaluation.
5087 * New native configurations
5089 GNU/Linux/m32r m32r-*-linux-gnu
5093 GDB's remote protocol now includes support for the 'p' packet. This
5094 packet is used to fetch individual registers from a remote inferior.
5096 * END-OF-LIFE registers[] compatibility module
5098 GDB's internal register infrastructure has been completely rewritten.
5099 The new infrastructure making possible the implementation of key new
5100 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5103 GDB 6.3 will be the last release to include the the registers[]
5104 compatibility module that allowed out-of-date configurations to
5105 continue to work. This change directly impacts the following
5115 powerpc bdm protocol
5117 Unless there is activity to revive these configurations, they will be
5118 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5120 * OBSOLETE configurations and files
5122 Configurations that have been declared obsolete in this release have
5123 been commented out. Unless there is activity to revive these
5124 configurations, the next release of GDB will have their sources
5125 permanently REMOVED.
5134 *** Changes in GDB 6.2.1:
5136 * MIPS `break main; run' gave an heuristic-fence-post warning
5138 When attempting to run even a simple program, a warning about
5139 heuristic-fence-post being hit would be reported. This problem has
5142 * MIPS IRIX 'long double' crashed GDB
5144 When examining a long double variable, GDB would get a segmentation
5145 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5146 IRIX long double values).
5150 A bug in the VAX stack code was causing problems with the "next"
5151 command. This problem has been fixed.
5153 *** Changes in GDB 6.2:
5155 * Fix for ``many threads''
5157 On GNU/Linux systems that use the NPTL threads library, a program
5158 rapidly creating and deleting threads would confuse GDB leading to the
5161 ptrace: No such process.
5162 thread_db_get_info: cannot get thread info: generic error
5164 This problem has been fixed.
5166 * "-async" and "-noasync" options removed.
5168 Support for the broken "-noasync" option has been removed (it caused
5171 * New ``start'' command.
5173 This command runs the program until the begining of the main procedure.
5175 * New BSD Kernel Data Access Library (libkvm) interface
5177 Using ``target kvm'' it is now possible to debug kernel core dumps and
5178 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5179 platforms. Currently supported (native-only) configurations are:
5181 FreeBSD/amd64 x86_64-*-freebsd*
5182 FreeBSD/i386 i?86-*-freebsd*
5183 NetBSD/i386 i?86-*-netbsd*
5184 NetBSD/m68k m68*-*-netbsd*
5185 NetBSD/sparc sparc-*-netbsd*
5186 OpenBSD/amd64 x86_64-*-openbsd*
5187 OpenBSD/i386 i?86-*-openbsd*
5188 OpenBSD/m68k m68*-openbsd*
5189 OpenBSD/sparc sparc-*-openbsd*
5191 * Signal trampoline code overhauled
5193 Many generic problems with GDB's signal handling code have been fixed.
5194 These include: backtraces through non-contiguous stacks; recognition
5195 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5196 call; backtrace through a signal trampoline; step into and out of
5197 signal handlers; and single-stepping in the signal trampoline.
5199 Please note that kernel bugs are a limiting factor here. These
5200 features have been shown to work on an s390 GNU/Linux system that
5201 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5203 * Cygwin support for DWARF 2 added.
5205 * New native configurations
5207 GNU/Linux/hppa hppa*-*-linux*
5208 OpenBSD/hppa hppa*-*-openbsd*
5209 OpenBSD/m68k m68*-*-openbsd*
5210 OpenBSD/m88k m88*-*-openbsd*
5211 OpenBSD/powerpc powerpc-*-openbsd*
5212 NetBSD/vax vax-*-netbsd*
5213 OpenBSD/vax vax-*-openbsd*
5215 * END-OF-LIFE frame compatibility module
5217 GDB's internal frame infrastructure has been completely rewritten.
5218 The new infrastructure making it possible to support key new features
5219 including DWARF 2 Call Frame Information. To aid in the task of
5220 migrating old configurations to this new infrastructure, a
5221 compatibility module, that allowed old configurations to continue to
5222 work, was also included.
5224 GDB 6.2 will be the last release to include this frame compatibility
5225 module. This change directly impacts the following configurations:
5235 Unless there is activity to revive these configurations, they will be
5236 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5238 * REMOVED configurations and files
5240 Sun 3, running SunOS 3 m68*-*-sunos3*
5241 Sun 3, running SunOS 4 m68*-*-sunos4*
5242 Sun 2, running SunOS 3 m68000-*-sunos3*
5243 Sun 2, running SunOS 4 m68000-*-sunos4*
5244 Motorola 680x0 running LynxOS m68*-*-lynxos*
5245 AT&T 3b1/Unix pc m68*-att-*
5246 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5247 decstation mips-dec-* mips-little-*
5248 riscos mips-*-riscos* mips-*-sysv*
5249 sonymips mips-sony-*
5250 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5252 *** Changes in GDB 6.1.1:
5254 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5256 The TUI (Text-mode User Interface) is now built as part of a default
5257 GDB configuration. It is enabled by either selecting the TUI with the
5258 command line option "-i=tui" or by running the separate "gdbtui"
5259 program. For more information on the TUI, see the manual "Debugging
5262 * Pending breakpoint support (also included in GDB 6.1)
5264 Support has been added to allow you to specify breakpoints in shared
5265 libraries that have not yet been loaded. If a breakpoint location
5266 cannot be found, and the "breakpoint pending" option is set to auto,
5267 GDB queries you if you wish to make the breakpoint pending on a future
5268 shared-library load. If and when GDB resolves the breakpoint symbol,
5269 the pending breakpoint is removed as one or more regular breakpoints
5272 Pending breakpoints are very useful for GCJ Java debugging.
5274 * Fixed ISO-C build problems
5276 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5277 non ISO-C code that stopped them being built using a more strict ISO-C
5278 compiler (e.g., IBM's C compiler).
5280 * Fixed build problem on IRIX 5
5282 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5283 wasn't able to compile compile on an IRIX 5 system.
5285 * Added execute permission to gdb/gdbserver/configure
5287 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5288 permission. This bug would cause configure to fail on a number of
5289 systems (Solaris, IRIX). Ref: server/519.
5291 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5293 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5294 has been updated to use constant array sizes.
5296 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5298 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5299 its generated DWARF Call Frame Info. This encoding was causing GDB to
5300 panic, that panic has been fixed. Ref: gdb/1628.
5302 * Fixed a problem when examining parameters in shared library code.
5304 When examining parameters in optimized shared library code generated
5305 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5306 not available''. GDB now correctly displays the variable's value.
5308 *** Changes in GDB 6.1:
5310 * Removed --with-mmalloc
5312 Support for the mmalloc memory manager has been removed, as it
5313 conflicted with the internal gdb byte cache.
5315 * Changes in AMD64 configurations
5317 The AMD64 target now includes the %cs and %ss registers. As a result
5318 the AMD64 remote protocol has changed; this affects the floating-point
5319 and SSE registers. If you rely on those registers for your debugging,
5320 you should upgrade gdbserver on the remote side.
5322 * Revised SPARC target
5324 The SPARC target has been completely revised, incorporating the
5325 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5326 support for LynxOS and SunOS 4 has been dropped. Calling functions
5327 from within GDB on operating systems with a non-executable stack
5328 (Solaris, OpenBSD) now works.
5332 GDB has a new C++ demangler which does a better job on the mangled
5333 names generated by current versions of g++. It also runs faster, so
5334 with this and other changes gdb should now start faster on large C++
5337 * DWARF 2 Location Expressions
5339 GDB support for location expressions has been extended to support function
5340 arguments and frame bases. Older versions of GDB could crash when they
5343 * C++ nested types and namespaces
5345 GDB's support for nested types and namespaces in C++ has been
5346 improved, especially if you use the DWARF 2 debugging format. (This
5347 is the default for recent versions of GCC on most platforms.)
5348 Specifically, if you have a class "Inner" defined within a class or
5349 namespace "Outer", then GDB realizes that the class's name is
5350 "Outer::Inner", not simply "Inner". This should greatly reduce the
5351 frequency of complaints about not finding RTTI symbols. In addition,
5352 if you are stopped at inside of a function defined within a namespace,
5353 GDB modifies its name lookup accordingly.
5355 * New native configurations
5357 NetBSD/amd64 x86_64-*-netbsd*
5358 OpenBSD/amd64 x86_64-*-openbsd*
5359 OpenBSD/alpha alpha*-*-openbsd*
5360 OpenBSD/sparc sparc-*-openbsd*
5361 OpenBSD/sparc64 sparc64-*-openbsd*
5363 * New debugging protocols
5365 M32R with SDI protocol m32r-*-elf*
5367 * "set prompt-escape-char" command deleted.
5369 The command "set prompt-escape-char" has been deleted. This command,
5370 and its very obscure effet on GDB's prompt, was never documented,
5371 tested, nor mentioned in the NEWS file.
5373 * OBSOLETE configurations and files
5375 Configurations that have been declared obsolete in this release have
5376 been commented out. Unless there is activity to revive these
5377 configurations, the next release of GDB will have their sources
5378 permanently REMOVED.
5380 Sun 3, running SunOS 3 m68*-*-sunos3*
5381 Sun 3, running SunOS 4 m68*-*-sunos4*
5382 Sun 2, running SunOS 3 m68000-*-sunos3*
5383 Sun 2, running SunOS 4 m68000-*-sunos4*
5384 Motorola 680x0 running LynxOS m68*-*-lynxos*
5385 AT&T 3b1/Unix pc m68*-att-*
5386 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5387 decstation mips-dec-* mips-little-*
5388 riscos mips-*-riscos* mips-*-sysv*
5389 sonymips mips-sony-*
5390 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5392 * REMOVED configurations and files
5394 SGI Irix-4.x mips-sgi-irix4 or iris4
5395 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5396 Z8000 simulator z8k-zilog-none or z8ksim
5397 Matsushita MN10200 w/simulator mn10200-*-*
5398 H8/500 simulator h8500-hitachi-hms or h8500hms
5399 HP/PA running BSD hppa*-*-bsd*
5400 HP/PA running OSF/1 hppa*-*-osf*
5401 HP/PA Pro target hppa*-*-pro*
5402 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5403 386BSD i[3456]86-*-bsd*
5404 Sequent family i[3456]86-sequent-sysv4*
5405 i[3456]86-sequent-sysv*
5406 i[3456]86-sequent-bsd*
5407 SPARC running LynxOS sparc-*-lynxos*
5408 SPARC running SunOS 4 sparc-*-sunos4*
5409 Tsqware Sparclet sparclet-*-*
5410 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5412 *** Changes in GDB 6.0:
5416 Support for debugging the Objective-C programming language has been
5417 integrated into GDB.
5419 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5421 DWARF 2's Call Frame Information makes available compiler generated
5422 information that more exactly describes the program's run-time stack.
5423 By using this information, GDB is able to provide more robust stack
5426 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5427 have been updated to use a new backtrace mechanism which includes
5428 DWARF 2 CFI support.
5432 GDB's remote protocol has been extended to include support for hosted
5433 file I/O (where the remote target uses GDB's file system). See GDB's
5434 remote protocol documentation for details.
5436 * All targets using the new architecture framework.
5438 All of GDB's targets have been updated to use the new internal
5439 architecture framework. The way is now open for future GDB releases
5440 to include cross-architecture native debugging support (i386 on amd64,
5443 * GNU/Linux's Thread Local Storage (TLS)
5445 GDB now includes support for for the GNU/Linux implementation of
5446 per-thread variables.
5448 * GNU/Linux's Native POSIX Thread Library (NPTL)
5450 GDB's thread code has been updated to work with either the new
5451 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5453 * Separate debug info.
5455 GDB, in conjunction with BINUTILS, now supports a mechanism for
5456 automatically loading debug information from a separate file. Instead
5457 of shipping full debug and non-debug versions of system libraries,
5458 system integrators can now instead ship just the stripped libraries
5459 and optional debug files.
5461 * DWARF 2 Location Expressions
5463 DWARF 2 Location Expressions allow the compiler to more completely
5464 describe the location of variables (even in optimized code) to the
5467 GDB now includes preliminary support for location expressions (support
5468 for DW_OP_piece is still missing).
5472 A number of long standing bugs that caused GDB to die while starting a
5473 Java application have been fixed. GDB's Java support is now
5474 considered "useable".
5476 * GNU/Linux support for fork, vfork, and exec.
5478 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5479 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5482 * GDB supports logging output to a file
5484 There are two new commands, "set logging" and "show logging", which can be
5485 used to capture GDB's output to a file.
5487 * The meaning of "detach" has changed for gdbserver
5489 The "detach" command will now resume the application, as documented. To
5490 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5493 * d10v, m68hc11 `regs' command deprecated
5495 The `info registers' command has been updated so that it displays the
5496 registers using a format identical to the old `regs' command.
5500 A new command, "maint set profile on/off", has been added. This command can
5501 be used to enable or disable profiling while running GDB, to profile a
5502 session or a set of commands. In addition there is a new configure switch,
5503 "--enable-profiling", which will cause GDB to be compiled with profiling
5504 data, for more informative profiling results.
5506 * Default MI syntax changed to "mi2".
5508 The default MI (machine interface) syntax, enabled by the command line
5509 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5510 "mi1", can be enabled by specifying the option "-i=mi1".
5512 Support for the original "mi0" syntax (included in GDB 5.0) has been
5515 Fix for gdb/192: removed extraneous space when displaying frame level.
5516 Fix for gdb/672: update changelist is now output in mi list format.
5517 Fix for gdb/702: a -var-assign that updates the value now shows up
5518 in a subsequent -var-update.
5520 * New native configurations.
5522 FreeBSD/amd64 x86_64-*-freebsd*
5524 * Multi-arched targets.
5526 HP/PA HPUX11 hppa*-*-hpux*
5527 Renesas M32R/D w/simulator m32r-*-elf*
5529 * OBSOLETE configurations and files
5531 Configurations that have been declared obsolete in this release have
5532 been commented out. Unless there is activity to revive these
5533 configurations, the next release of GDB will have their sources
5534 permanently REMOVED.
5536 Z8000 simulator z8k-zilog-none or z8ksim
5537 Matsushita MN10200 w/simulator mn10200-*-*
5538 H8/500 simulator h8500-hitachi-hms or h8500hms
5539 HP/PA running BSD hppa*-*-bsd*
5540 HP/PA running OSF/1 hppa*-*-osf*
5541 HP/PA Pro target hppa*-*-pro*
5542 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5543 Sequent family i[3456]86-sequent-sysv4*
5544 i[3456]86-sequent-sysv*
5545 i[3456]86-sequent-bsd*
5546 Tsqware Sparclet sparclet-*-*
5547 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5549 * REMOVED configurations and files
5552 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5553 IBM AIX PS/2 i[3456]86-*-aix
5554 i386 running Mach 3.0 i[3456]86-*-mach3*
5555 i386 running Mach i[3456]86-*-mach*
5556 i386 running OSF/1 i[3456]86-*osf1mk*
5557 HP/Apollo 68k Family m68*-apollo*-sysv*,
5559 m68*-hp-bsd*, m68*-hp-hpux*
5560 Argonaut Risc Chip (ARC) arc-*-*
5561 Mitsubishi D30V d30v-*-*
5562 Fujitsu FR30 fr30-*-elf*
5563 OS/9000 i[34]86-*-os9k
5564 I960 with MON960 i960-*-coff
5566 * MIPS $fp behavior changed
5568 The convenience variable $fp, for the MIPS, now consistently returns
5569 the address of the current frame's base. Previously, depending on the
5570 context, $fp could refer to either $sp or the current frame's base
5571 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5572 The GNU Source-Level Debugger''.
5574 *** Changes in GDB 5.3:
5576 * GNU/Linux shared library multi-threaded performance improved.
5578 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5579 `/proc', in preference to `ptrace' for memory reads. This may result
5580 in an improvement in the start-up time of multi-threaded, shared
5581 library applications when run under GDB. One GDB user writes: ``loads
5582 shared libs like mad''.
5584 * ``gdbserver'' now supports multi-threaded applications on some targets
5586 Support for debugging multi-threaded applications which use
5587 the GNU/Linux LinuxThreads package has been added for
5588 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5589 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5591 * GDB now supports C/C++ preprocessor macros.
5593 GDB now expands preprocessor macro invocations in C/C++ expressions,
5594 and provides various commands for showing macro definitions and how
5597 The new command `macro expand EXPRESSION' expands any macro
5598 invocations in expression, and shows the result.
5600 The new command `show macro MACRO-NAME' shows the definition of the
5601 macro named MACRO-NAME, and where it was defined.
5603 Most compilers don't include information about macros in the debugging
5604 information by default. In GCC 3.1, for example, you need to compile
5605 your program with the options `-gdwarf-2 -g3'. If the macro
5606 information is present in the executable, GDB will read it.
5608 * Multi-arched targets.
5610 DEC Alpha (partial) alpha*-*-*
5611 DEC VAX (partial) vax-*-*
5613 National Semiconductor NS32000 (partial) ns32k-*-*
5614 Motorola 68000 (partial) m68k-*-*
5615 Motorola MCORE mcore-*-*
5619 Fujitsu FRV architecture added by Red Hat frv*-*-*
5622 * New native configurations
5624 Alpha NetBSD alpha*-*-netbsd*
5625 SH NetBSD sh*-*-netbsdelf*
5626 MIPS NetBSD mips*-*-netbsd*
5627 UltraSPARC NetBSD sparc64-*-netbsd*
5629 * OBSOLETE configurations and files
5631 Configurations that have been declared obsolete in this release have
5632 been commented out. Unless there is activity to revive these
5633 configurations, the next release of GDB will have their sources
5634 permanently REMOVED.
5636 Mitsubishi D30V d30v-*-*
5637 OS/9000 i[34]86-*-os9k
5638 IBM AIX PS/2 i[3456]86-*-aix
5639 Fujitsu FR30 fr30-*-elf*
5640 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5641 Argonaut Risc Chip (ARC) arc-*-*
5642 i386 running Mach 3.0 i[3456]86-*-mach3*
5643 i386 running Mach i[3456]86-*-mach*
5644 i386 running OSF/1 i[3456]86-*osf1mk*
5645 HP/Apollo 68k Family m68*-apollo*-sysv*,
5647 m68*-hp-bsd*, m68*-hp-hpux*
5648 I960 with MON960 i960-*-coff
5650 * OBSOLETE languages
5652 CHILL, a Pascal like language used by telecommunications companies.
5654 * REMOVED configurations and files
5656 AMD 29k family via UDI a29k-amd-udi, udi29k
5657 A29K VxWorks a29k-*-vxworks
5658 AMD 29000 embedded, using EBMON a29k-none-none
5659 AMD 29000 embedded with COFF a29k-none-coff
5660 AMD 29000 embedded with a.out a29k-none-aout
5662 testsuite/gdb.hp/gdb.threads-hp/ directory
5664 * New command "set max-user-call-depth <nnn>"
5666 This command allows the user to limit the call depth of user-defined
5667 commands. The default is 1024.
5669 * Changes in FreeBSD/i386 native debugging.
5671 Support for the "generate-core-file" has been added.
5673 * New commands "dump", "append", and "restore".
5675 These commands allow data to be copied from target memory
5676 to a bfd-format or binary file (dump and append), and back
5677 from a file into memory (restore).
5679 * Improved "next/step" support on multi-processor Alpha Tru64.
5681 The previous single-step mechanism could cause unpredictable problems,
5682 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5683 of a software single-step mechanism prevents this.
5685 *** Changes in GDB 5.2.1:
5693 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5694 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5695 Fix, by Joel Brobecker imported from mainline.
5697 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5698 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5699 Fix, by Fred Fish, imported from mainline.
5701 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5702 Surprisingly enough, it works now.
5703 By Michal Ludvig, imported from mainline.
5705 i386 hardware watchpoint support:
5706 avoid misses on second run for some targets.
5707 By Pierre Muller, imported from mainline.
5709 *** Changes in GDB 5.2:
5711 * New command "set trust-readonly-sections on[off]".
5713 This command is a hint that tells gdb that read-only sections
5714 really are read-only (ie. that their contents will not change).
5715 In this mode, gdb will go to the object file rather than the
5716 target to read memory from read-only sections (such as ".text").
5717 This can be a significant performance improvement on some
5718 (notably embedded) targets.
5720 * New command "generate-core-file" (or "gcore").
5722 This new gdb command allows the user to drop a core file of the child
5723 process state at any time. So far it's been implemented only for
5724 GNU/Linux and Solaris, but should be relatively easily ported to other
5725 hosts. Argument is core file name (defaults to core.<pid>).
5727 * New command line option
5729 GDB now accepts --pid or -p followed by a process id.
5731 * Change in command line behavior -- corefiles vs. process ids.
5733 There is a subtle behavior in the way in which GDB handles
5734 command line arguments. The first non-flag argument is always
5735 a program to debug, but the second non-flag argument may either
5736 be a corefile or a process id. Previously, GDB would attempt to
5737 open the second argument as a corefile, and if that failed, would
5738 issue a superfluous error message and then attempt to attach it as
5739 a process. Now, if the second argument begins with a non-digit,
5740 it will be treated as a corefile. If it begins with a digit,
5741 GDB will attempt to attach it as a process, and if no such process
5742 is found, will then attempt to open it as a corefile.
5744 * Changes in ARM configurations.
5746 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5747 configuration is fully multi-arch.
5749 * New native configurations
5751 ARM NetBSD arm*-*-netbsd*
5752 x86 OpenBSD i[3456]86-*-openbsd*
5753 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5754 Sparc64 running FreeBSD sparc64-*-freebsd*
5758 Sanyo XStormy16 xstormy16-elf
5760 * OBSOLETE configurations and files
5762 Configurations that have been declared obsolete in this release have
5763 been commented out. Unless there is activity to revive these
5764 configurations, the next release of GDB will have their sources
5765 permanently REMOVED.
5767 AMD 29k family via UDI a29k-amd-udi, udi29k
5768 A29K VxWorks a29k-*-vxworks
5769 AMD 29000 embedded, using EBMON a29k-none-none
5770 AMD 29000 embedded with COFF a29k-none-coff
5771 AMD 29000 embedded with a.out a29k-none-aout
5773 testsuite/gdb.hp/gdb.threads-hp/ directory
5775 * REMOVED configurations and files
5777 TI TMS320C80 tic80-*-*
5779 PowerPC Solaris powerpcle-*-solaris*
5780 PowerPC Windows NT powerpcle-*-cygwin32
5781 PowerPC Netware powerpc-*-netware*
5782 Harris/CXUX m88k m88*-harris-cxux*
5783 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5784 ns32k-utek-sysv* ns32k-utek-*
5785 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5786 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5787 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5788 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5789 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5791 * Changes to command line processing
5793 The new `--args' feature can be used to specify command-line arguments
5794 for the inferior from gdb's command line.
5796 * Changes to key bindings
5798 There is a new `operate-and-get-next' function bound to `C-o'.
5800 *** Changes in GDB 5.1.1
5802 Fix compile problem on DJGPP.
5804 Fix a problem with floating-point registers on the i386 being
5807 Fix to stop GDB crashing on .debug_str debug info.
5809 Numerous documentation fixes.
5811 Numerous testsuite fixes.
5813 *** Changes in GDB 5.1:
5815 * New native configurations
5817 Alpha FreeBSD alpha*-*-freebsd*
5818 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5819 MIPS GNU/Linux mips*-*-linux*
5820 MIPS SGI Irix 6.x mips*-sgi-irix6*
5821 ia64 AIX ia64-*-aix*
5822 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5826 Motorola 68HC11 and 68HC12 m68hc11-elf
5828 UltraSparc running GNU/Linux sparc64-*-linux*
5830 * OBSOLETE configurations and files
5832 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5833 Harris/CXUX m88k m88*-harris-cxux*
5834 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5835 ns32k-utek-sysv* ns32k-utek-*
5836 TI TMS320C80 tic80-*-*
5838 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5839 PowerPC Solaris powerpcle-*-solaris*
5840 PowerPC Windows NT powerpcle-*-cygwin32
5841 PowerPC Netware powerpc-*-netware*
5842 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5843 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5844 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5845 Apple Macintosh (MPW) host N/A
5847 stuff.c (Program to stuff files into a specially prepared space in kdb)
5848 kdb-start.c (Main loop for the standalone kernel debugger)
5850 Configurations that have been declared obsolete in this release have
5851 been commented out. Unless there is activity to revive these
5852 configurations, the next release of GDB will have their sources
5853 permanently REMOVED.
5855 * REMOVED configurations and files
5857 Altos 3068 m68*-altos-*
5858 Convex c1-*-*, c2-*-*
5860 ARM RISCix arm-*-* (as host)
5864 * GDB has been converted to ISO C.
5866 GDB's source code has been converted to ISO C. In particular, the
5867 sources are fully protoized, and rely on standard headers being
5872 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5874 * The MI enabled by default.
5876 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5877 revised and enabled by default. Packages which use GDB as a debugging
5878 engine behind a UI or another front end are encouraged to switch to
5879 using the GDB/MI interface, instead of the old annotations interface
5880 which is now deprecated.
5882 * Support for debugging Pascal programs.
5884 GDB now includes support for debugging Pascal programs. The following
5885 main features are supported:
5887 - Pascal-specific data types such as sets;
5889 - automatic recognition of Pascal sources based on file-name
5892 - Pascal-style display of data types, variables, and functions;
5894 - a Pascal expression parser.
5896 However, some important features are not yet supported.
5898 - Pascal string operations are not supported at all;
5900 - there are some problems with boolean types;
5902 - Pascal type hexadecimal constants are not supported
5903 because they conflict with the internal variables format;
5905 - support for Pascal objects and classes is not full yet;
5907 - unlike Pascal, GDB is case-sensitive for symbol names.
5909 * Changes in completion.
5911 Commands such as `shell', `run' and `set args', which pass arguments
5912 to inferior programs, now complete on file names, similar to what
5913 users expect at the shell prompt.
5915 Commands which accept locations, such as `disassemble', `print',
5916 `breakpoint', `until', etc. now complete on filenames as well as
5917 program symbols. Thus, if you type "break foob TAB", and the source
5918 files linked into the programs include `foobar.c', that file name will
5919 be one of the candidates for completion. However, file names are not
5920 considered for completion after you typed a colon that delimits a file
5921 name from a name of a function in that file, as in "break foo.c:bar".
5923 `set demangle-style' completes on available demangling styles.
5925 * New platform-independent commands:
5927 It is now possible to define a post-hook for a command as well as a
5928 hook that runs before the command. For more details, see the
5929 documentation of `hookpost' in the GDB manual.
5931 * Changes in GNU/Linux native debugging.
5933 Support for debugging multi-threaded programs has been completely
5934 revised for all platforms except m68k and sparc. You can now debug as
5935 many threads as your system allows you to have.
5937 Attach/detach is supported for multi-threaded programs.
5939 Support for SSE registers was added for x86. This doesn't work for
5940 multi-threaded programs though.
5942 * Changes in MIPS configurations.
5944 Multi-arch support is enabled for all MIPS configurations.
5946 GDB can now be built as native debugger on SGI Irix 6.x systems for
5947 debugging n32 executables. (Debugging 64-bit executables is not yet
5950 * Unified support for hardware watchpoints in all x86 configurations.
5952 Most (if not all) native x86 configurations support hardware-assisted
5953 breakpoints and watchpoints in a unified manner. This support
5954 implements debug register sharing between watchpoints, which allows to
5955 put a virtually infinite number of watchpoints on the same address,
5956 and also supports watching regions up to 16 bytes with several debug
5959 The new maintenance command `maintenance show-debug-regs' toggles
5960 debugging print-outs in functions that insert, remove, and test
5961 watchpoints and hardware breakpoints.
5963 * Changes in the DJGPP native configuration.
5965 New command ``info dos sysinfo'' displays assorted information about
5966 the CPU, OS, memory, and DPMI server.
5968 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5969 display information about segment descriptors stored in GDT, LDT, and
5972 New commands ``info dos pde'' and ``info dos pte'' display entries
5973 from Page Directory and Page Tables (for now works with CWSDPMI only).
5974 New command ``info dos address-pte'' displays the Page Table entry for
5975 a given linear address.
5977 GDB can now pass command lines longer than 126 characters to the
5978 program being debugged (requires an update to the libdbg.a library
5979 which is part of the DJGPP development kit).
5981 DWARF2 debug info is now supported.
5983 It is now possible to `step' and `next' through calls to `longjmp'.
5985 * Changes in documentation.
5987 All GDB documentation was converted to GFDL, the GNU Free
5988 Documentation License.
5990 Tracepoints-related commands are now fully documented in the GDB
5993 TUI, the Text-mode User Interface, is now documented in the manual.
5995 Tracepoints-related commands are now fully documented in the GDB
5998 The "GDB Internals" manual now has an index. It also includes
5999 documentation of `ui_out' functions, GDB coding standards, x86
6000 hardware watchpoints, and memory region attributes.
6002 * GDB's version number moved to ``version.in''
6004 The Makefile variable VERSION has been replaced by the file
6005 ``version.in''. People creating GDB distributions should update the
6006 contents of this file.
6010 GUD support is now a standard part of the EMACS distribution.
6012 *** Changes in GDB 5.0:
6014 * Improved support for debugging FP programs on x86 targets
6016 Unified and much-improved support for debugging floating-point
6017 programs on all x86 targets. In particular, ``info float'' now
6018 displays the FP registers in the same format on all x86 targets, with
6019 greater level of detail.
6021 * Improvements and bugfixes in hardware-assisted watchpoints
6023 It is now possible to watch array elements, struct members, and
6024 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6025 on x86 targets no longer erroneously trigger when the address is
6028 * Improvements in the native DJGPP version of GDB
6030 The distribution now includes all the scripts and auxiliary files
6031 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6032 machines ``out of the box''.
6034 The DJGPP version can now debug programs that use signals. It is
6035 possible to catch signals that happened in the debuggee, deliver
6036 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6037 would kill the program being debugged.) Programs that hook hardware
6038 interrupts (keyboard, timer, etc.) can also be debugged.
6040 It is now possible to debug DJGPP programs that redirect their
6041 standard handles or switch them to raw (as opposed to cooked) mode, or
6042 even close them. The command ``run < foo > bar'' works as expected,
6043 and ``info terminal'' reports useful information about the debuggee's
6044 terminal, including raw/cooked mode, redirection, etc.
6046 The DJGPP version now uses termios functions for console I/O, which
6047 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6050 DOS-style file names with drive letters are now fully supported by
6053 It is now possible to debug DJGPP programs that switch their working
6054 directory. It is also possible to rerun the debuggee any number of
6055 times without restarting GDB; thus, you can use the same setup,
6056 breakpoints, etc. for many debugging sessions.
6058 * New native configurations
6060 ARM GNU/Linux arm*-*-linux*
6061 PowerPC GNU/Linux powerpc-*-linux*
6065 Motorola MCore mcore-*-*
6066 x86 VxWorks i[3456]86-*-vxworks*
6067 PowerPC VxWorks powerpc-*-vxworks*
6068 TI TMS320C80 tic80-*-*
6070 * OBSOLETE configurations
6072 Altos 3068 m68*-altos-*
6073 Convex c1-*-*, c2-*-*
6075 ARM RISCix arm-*-* (as host)
6078 Configurations that have been declared obsolete will be commented out,
6079 but the code will be left in place. If there is no activity to revive
6080 these configurations before the next release of GDB, the sources will
6081 be permanently REMOVED.
6083 * Gould support removed
6085 Support for the Gould PowerNode and NP1 has been removed.
6087 * New features for SVR4
6089 On SVR4 native platforms (such as Solaris), if you attach to a process
6090 without first loading a symbol file, GDB will now attempt to locate and
6091 load symbols from the running process's executable file.
6093 * Many C++ enhancements
6095 C++ support has been greatly improved. Overload resolution now works properly
6096 in almost all cases. RTTI support is on the way.
6098 * Remote targets can connect to a sub-program
6100 A popen(3) style serial-device has been added. This device starts a
6101 sub-process (such as a stand-alone simulator) and then communicates
6102 with that. The sub-program to run is specified using the syntax
6103 ``|<program> <args>'' vis:
6105 (gdb) set remotedebug 1
6106 (gdb) target extended-remote |mn10300-elf-sim program-args
6108 * MIPS 64 remote protocol
6110 A long standing bug in the mips64 remote protocol where by GDB
6111 expected certain 32 bit registers (ex SR) to be transfered as 32
6112 instead of 64 bits has been fixed.
6114 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6115 added to provide backward compatibility with older versions of GDB.
6117 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6119 The command ``set remotebinarydownload'' command has been replaced by
6120 ``set remote X-packet''. Other commands in ``set remote'' family
6121 include ``set remote P-packet''.
6123 * Breakpoint commands accept ranges.
6125 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6126 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6127 ``tracepoint passcount'' also accepts a range of tracepoints.
6129 * ``apropos'' command added.
6131 The ``apropos'' command searches through command names and
6132 documentation strings, printing out matches, making it much easier to
6133 try to find a command that does what you are looking for.
6137 A new machine oriented interface (MI) has been added to GDB. This
6138 interface is designed for debug environments running GDB as a separate
6139 process. This is part of the long term libGDB project. See the
6140 "GDB/MI" chapter of the GDB manual for further information. It can be
6141 enabled by configuring with:
6143 .../configure --enable-gdbmi
6145 *** Changes in GDB-4.18:
6147 * New native configurations
6149 HP-UX 10.20 hppa*-*-hpux10.20
6150 HP-UX 11.x hppa*-*-hpux11.0*
6151 M68K GNU/Linux m68*-*-linux*
6155 Fujitsu FR30 fr30-*-elf*
6156 Intel StrongARM strongarm-*-*
6157 Mitsubishi D30V d30v-*-*
6159 * OBSOLETE configurations
6161 Gould PowerNode, NP1 np1-*-*, pn-*-*
6163 Configurations that have been declared obsolete will be commented out,
6164 but the code will be left in place. If there is no activity to revive
6165 these configurations before the next release of GDB, the sources will
6166 be permanently REMOVED.
6170 As a compatibility experiment, GDB's source files buildsym.h and
6171 buildsym.c have been converted to pure standard C, no longer
6172 containing any K&R compatibility code. We believe that all systems in
6173 use today either come with a standard C compiler, or have a GCC port
6174 available. If this is not true, please report the affected
6175 configuration to bug-gdb@gnu.org immediately. See the README file for
6176 information about getting a standard C compiler if you don't have one
6181 GDB now uses readline 2.2.
6183 * set extension-language
6185 You can now control the mapping between filename extensions and source
6186 languages by using the `set extension-language' command. For instance,
6187 you can ask GDB to treat .c files as C++ by saying
6188 set extension-language .c c++
6189 The command `info extensions' lists all of the recognized extensions
6190 and their associated languages.
6192 * Setting processor type for PowerPC and RS/6000
6194 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6195 you can use the `set processor' command to specify what variant of the
6196 PowerPC family you are debugging. The command
6200 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6201 following PowerPC and RS6000 variants:
6203 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6204 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6206 403GC IBM PowerPC 403GC
6207 505 Motorola PowerPC 505
6208 860 Motorola PowerPC 860 or 850
6209 601 Motorola PowerPC 601
6210 602 Motorola PowerPC 602
6211 603 Motorola/IBM PowerPC 603 or 603e
6212 604 Motorola PowerPC 604 or 604e
6213 750 Motorola/IBM PowerPC 750 or 750
6215 At the moment, this command just tells GDB what to name the
6216 special-purpose processor registers. Since almost all the affected
6217 registers are inaccessible to user-level programs, this command is
6218 only useful for remote debugging in its present form.
6222 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6223 more extensive support for HP-UX. Added features include shared
6224 library support, kernel threads and hardware watchpoints for 11.00,
6225 support for HP's ANSI C and C++ compilers, and a compatibility mode
6226 for xdb and dbx commands.
6230 HP's donation includes the new concept of catchpoints, which is a
6231 generalization of the old catch command. On HP-UX, it is now possible
6232 to catch exec, fork, and vfork, as well as library loading.
6234 This means that the existing catch command has changed; its first
6235 argument now specifies the type of catch to be set up. See the
6236 output of "help catch" for a list of catchpoint types.
6238 * Debugging across forks
6240 On HP-UX, you can choose which process to debug when a fork() happens
6245 HP has donated a curses-based terminal user interface (TUI). To get
6246 it, build with --enable-tui. Although this can be enabled for any
6247 configuration, at present it only works for native HP debugging.
6249 * GDB remote protocol additions
6251 A new protocol packet 'X' that writes binary data is now available.
6252 Default behavior is to try 'X', then drop back to 'M' if the stub
6253 fails to respond. The settable variable `remotebinarydownload'
6254 allows explicit control over the use of 'X'.
6256 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6257 full 64-bit address. The command
6259 set remoteaddresssize 32
6261 can be used to revert to the old behaviour. For existing remote stubs
6262 the change should not be noticed, as the additional address information
6265 In order to assist in debugging stubs, you may use the maintenance
6266 command `packet' to send any text string to the stub. For instance,
6268 maint packet heythere
6270 sends the packet "$heythere#<checksum>". Note that it is very easy to
6271 disrupt a debugging session by sending the wrong packet at the wrong
6274 The compare-sections command allows you to compare section data on the
6275 target to what is in the executable file without uploading or
6276 downloading, by comparing CRC checksums.
6278 * Tracing can collect general expressions
6280 You may now collect general expressions at tracepoints. This requires
6281 further additions to the target-side stub; see tracepoint.c and
6282 doc/agentexpr.texi for further details.
6284 * mask-address variable for Mips
6286 For Mips targets, you may control the zeroing of the upper 32 bits of
6287 a 64-bit address by entering `set mask-address on'. This is mainly
6288 of interest to users of embedded R4xxx and R5xxx processors.
6290 * Higher serial baud rates
6292 GDB's serial code now allows you to specify baud rates 57600, 115200,
6293 230400, and 460800 baud. (Note that your host system may not be able
6294 to achieve all of these rates.)
6298 The i960 configuration now includes an initial implementation of a
6299 builtin simulator, contributed by Jim Wilson.
6302 *** Changes in GDB-4.17:
6304 * New native configurations
6306 Alpha GNU/Linux alpha*-*-linux*
6307 Unixware 2.x i[3456]86-unixware2*
6308 Irix 6.x mips*-sgi-irix6*
6309 PowerPC GNU/Linux powerpc-*-linux*
6310 PowerPC Solaris powerpcle-*-solaris*
6311 Sparc GNU/Linux sparc-*-linux*
6312 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6316 Argonaut Risc Chip (ARC) arc-*-*
6317 Hitachi H8/300S h8300*-*-*
6318 Matsushita MN10200 w/simulator mn10200-*-*
6319 Matsushita MN10300 w/simulator mn10300-*-*
6320 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6321 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6322 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6323 Mitsubishi D10V w/simulator d10v-*-*
6324 Mitsubishi M32R/D w/simulator m32r-*-elf*
6325 Tsqware Sparclet sparclet-*-*
6326 NEC V850 w/simulator v850-*-*
6328 * New debugging protocols
6330 ARM with RDI protocol arm*-*-*
6331 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6332 DDB and LSI variants of PMON protocol mips*-*-*
6333 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6334 PowerPC with SDS protocol powerpc{,le}-*-eabi
6335 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6339 All configurations can now understand and use the DWARF 2 debugging
6340 format. The choice is automatic, if the symbol file contains DWARF 2
6345 GDB now includes basic Java language support. This support is
6346 only useful with Java compilers that produce native machine code.
6348 * solib-absolute-prefix and solib-search-path
6350 For SunOS and SVR4 shared libraries, you may now set the prefix for
6351 loading absolute shared library symbol files, and the search path for
6352 locating non-absolute shared library symbol files.
6354 * Live range splitting
6356 GDB can now effectively debug code for which GCC has performed live
6357 range splitting as part of its optimization. See gdb/doc/LRS for
6358 more details on the expected format of the stabs information.
6362 GDB's support for the GNU Hurd, including thread debugging, has been
6363 updated to work with current versions of the Hurd.
6367 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6368 instruction set. ARM GDB automatically detects when Thumb
6369 instructions are in use, and adjusts disassembly and backtracing
6374 GDB's MIPS target configurations now handle the MIP16 16-bit
6379 GDB now includes support for overlays; if an executable has been
6380 linked such that multiple sections are based at the same address, GDB
6381 will decide which section to use for symbolic info. You can choose to
6382 control the decision manually, using overlay commands, or implement
6383 additional target-side support and use "overlay load-target" to bring
6384 in the overlay mapping. Do "help overlay" for more detail.
6388 The command "info symbol <address>" displays information about
6389 the symbol at the specified address.
6393 The standard remote protocol now includes an extension that allows
6394 asynchronous collection and display of trace data. This requires
6395 extensive support in the target-side debugging stub. Tracing mode
6396 includes a new interaction mode in GDB and new commands: see the
6397 file tracepoint.c for more details.
6401 Configurations for embedded MIPS now include a simulator contributed
6402 by Cygnus Solutions. The simulator supports the instruction sets
6403 of most MIPS variants.
6407 Sparc configurations may now include the ERC32 simulator contributed
6408 by the European Space Agency. The simulator is not built into
6409 Sparc targets by default; configure with --enable-sim to include it.
6413 For target configurations that may include multiple variants of a
6414 basic architecture (such as MIPS and SH), you may now set the
6415 architecture explicitly. "set arch" sets, "info arch" lists
6416 the possible architectures.
6418 *** Changes in GDB-4.16:
6420 * New native configurations
6422 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6423 M68K NetBSD m68k-*-netbsd*
6424 PowerPC AIX 4.x powerpc-*-aix*
6425 PowerPC MacOS powerpc-*-macos*
6426 PowerPC Windows NT powerpcle-*-cygwin32
6427 RS/6000 AIX 4.x rs6000-*-aix4*
6431 ARM with RDP protocol arm-*-*
6432 I960 with MON960 i960-*-coff
6433 MIPS VxWorks mips*-*-vxworks*
6434 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6435 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6437 Matra Sparclet sparclet-*-*
6441 The powerpc-eabi configuration now includes the PSIM simulator,
6442 contributed by Andrew Cagney, with assistance from Mike Meissner.
6443 PSIM is a very elaborate model of the PowerPC, including not only
6444 basic instruction set execution, but also details of execution unit
6445 performance and I/O hardware. See sim/ppc/README for more details.
6449 GDB now works with Solaris 2.5.
6451 * Windows 95/NT native
6453 GDB will now work as a native debugger on Windows 95 and Windows NT.
6454 To build it from source, you must use the "gnu-win32" environment,
6455 which uses a DLL to emulate enough of Unix to run the GNU tools.
6456 Further information, binaries, and sources are available at
6457 ftp.cygnus.com, under pub/gnu-win32.
6459 * dont-repeat command
6461 If a user-defined command includes the command `dont-repeat', then the
6462 command will not be repeated if the user just types return. This is
6463 useful if the command is time-consuming to run, so that accidental
6464 extra keystrokes don't run the same command many times.
6466 * Send break instead of ^C
6468 The standard remote protocol now includes an option to send a break
6469 rather than a ^C to the target in order to interrupt it. By default,
6470 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6472 * Remote protocol timeout
6474 The standard remote protocol includes a new variable `remotetimeout'
6475 that allows you to set the number of seconds before GDB gives up trying
6476 to read from the target. The default value is 2.
6478 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6480 By default GDB will automatically keep track of objects as they are
6481 loaded and unloaded by the dynamic linker. By using the command `set
6482 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6483 when shared library events occur, thus allowing you to set breakpoints
6484 in shared libraries which are explicitly loaded by the inferior.
6486 Note this feature does not work on hpux8. On hpux9 you must link
6487 /usr/lib/end.o into your program. This feature should work
6488 automatically on hpux10.
6490 * Irix 5.x hardware watchpoint support
6492 Irix 5 configurations now support the use of hardware watchpoints.
6494 * Mips protocol "SYN garbage limit"
6496 When debugging a Mips target using the `target mips' protocol, you
6497 may set the number of characters that GDB will ignore by setting
6498 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6499 every character. The default value is 1050.
6501 * Recording and replaying remote debug sessions
6503 If you set `remotelogfile' to the name of a file, gdb will write to it
6504 a recording of a remote debug session. This recording may then be
6505 replayed back to gdb using "gdbreplay". See gdbserver/README for
6506 details. This is useful when you have a problem with GDB while doing
6507 remote debugging; you can make a recording of the session and send it
6508 to someone else, who can then recreate the problem.
6510 * Speedups for remote debugging
6512 GDB includes speedups for downloading and stepping MIPS systems using
6513 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6514 and more efficient S-record downloading.
6516 * Memory use reductions and statistics collection
6518 GDB now uses less memory and reports statistics about memory usage.
6519 Try the `maint print statistics' command, for example.
6521 *** Changes in GDB-4.15:
6523 * Psymtabs for XCOFF
6525 The symbol reader for AIX GDB now uses partial symbol tables. This
6526 can greatly improve startup time, especially for large executables.
6528 * Remote targets use caching
6530 Remote targets now use a data cache to speed up communication with the
6531 remote side. The data cache could lead to incorrect results because
6532 it doesn't know about volatile variables, thus making it impossible to
6533 debug targets which use memory mapped I/O devices. `set remotecache
6534 off' turns the the data cache off.
6536 * Remote targets may have threads
6538 The standard remote protocol now includes support for multiple threads
6539 in the target system, using new protocol commands 'H' and 'T'. See
6540 gdb/remote.c for details.
6544 If GDB is configured with `--enable-netrom', then it will include
6545 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6546 acts as though it is a bank of ROM on the target board, but you can
6547 write into it over the network. GDB's support consists only of
6548 support for fast loading into the emulated ROM; to debug, you must use
6549 another protocol, such as standard remote protocol. The usual
6550 sequence is something like
6552 target nrom <netrom-hostname>
6554 target remote <netrom-hostname>:1235
6558 GDB now includes support for the Apple Macintosh, as a host only. It
6559 may be run as either an MPW tool or as a standalone application, and
6560 it can debug through the serial port. All the usual GDB commands are
6561 available, but to the target command, you must supply "serial" as the
6562 device type instead of "/dev/ttyXX". See mpw-README in the main
6563 directory for more information on how to build. The MPW configuration
6564 scripts */mpw-config.in support only a few targets, and only the
6565 mips-idt-ecoff target has been tested.
6569 GDB configuration now uses autoconf. This is not user-visible,
6570 but does simplify configuration and building.
6574 GDB now supports hpux10.
6576 *** Changes in GDB-4.14:
6578 * New native configurations
6580 x86 FreeBSD i[345]86-*-freebsd
6581 x86 NetBSD i[345]86-*-netbsd
6582 NS32k NetBSD ns32k-*-netbsd
6583 Sparc NetBSD sparc-*-netbsd
6587 A29K VxWorks a29k-*-vxworks
6588 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6589 CPU32 EST-300 emulator m68*-*-est*
6590 PowerPC ELF powerpc-*-elf
6593 * Alpha OSF/1 support for procfs
6595 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6596 possible to attach to running processes. As the mounting of the /proc
6597 filesystem is optional on the Alpha, GDB automatically determines
6598 the availability of /proc during startup. This can lead to problems
6599 if /proc is unmounted after GDB has been started.
6601 * Arguments to user-defined commands
6603 User commands may accept up to 10 arguments separated by whitespace.
6604 Arguments are accessed within the user command via $arg0..$arg9. A
6607 print $arg0 + $arg1 + $arg2
6609 To execute the command use:
6612 Defines the command "adder" which prints the sum of its three arguments.
6613 Note the arguments are text substitutions, so they may reference variables,
6614 use complex expressions, or even perform inferior function calls.
6616 * New `if' and `while' commands
6618 This makes it possible to write more sophisticated user-defined
6619 commands. Both commands take a single argument, which is the
6620 expression to evaluate, and must be followed by the commands to
6621 execute, one per line, if the expression is nonzero, the list being
6622 terminated by the word `end'. The `if' command list may include an
6623 `else' word, which causes the following commands to be executed only
6624 if the expression is zero.
6626 * Fortran source language mode
6628 GDB now includes partial support for Fortran 77. It will recognize
6629 Fortran programs and can evaluate a subset of Fortran expressions, but
6630 variables and functions may not be handled correctly. GDB will work
6631 with G77, but does not yet know much about symbols emitted by other
6634 * Better HPUX support
6636 Most debugging facilities now work on dynamic executables for HPPAs
6637 running hpux9 or later. You can attach to running dynamically linked
6638 processes, but by default the dynamic libraries will be read-only, so
6639 for instance you won't be able to put breakpoints in them. To change
6640 that behavior do the following before running the program:
6646 This will cause the libraries to be mapped private and read-write.
6647 To revert to the normal behavior, do this:
6653 You cannot set breakpoints or examine data in the library until after
6654 the library is loaded if the function/data symbols do not have
6657 GDB can now also read debug symbols produced by the HP C compiler on
6658 HPPAs (sorry, no C++, Fortran or 68k support).
6660 * Target byte order now dynamically selectable
6662 You can choose which byte order to use with a target system, via the
6663 commands "set endian big" and "set endian little", and you can see the
6664 current setting by using "show endian". You can also give the command
6665 "set endian auto", in which case GDB will use the byte order
6666 associated with the executable. Currently, only embedded MIPS
6667 configurations support dynamic selection of target byte order.
6669 * New DOS host serial code
6671 This version uses DPMI interrupts to handle buffered I/O, so you
6672 no longer need to run asynctsr when debugging boards connected to
6675 *** Changes in GDB-4.13:
6677 * New "complete" command
6679 This lists all the possible completions for the rest of the line, if it
6680 were to be given as a command itself. This is intended for use by emacs.
6682 * Trailing space optional in prompt
6684 "set prompt" no longer adds a space for you after the prompt you set. This
6685 allows you to set a prompt which ends in a space or one that does not.
6687 * Breakpoint hit counts
6689 "info break" now displays a count of the number of times the breakpoint
6690 has been hit. This is especially useful in conjunction with "ignore"; you
6691 can ignore a large number of breakpoint hits, look at the breakpoint info
6692 to see how many times the breakpoint was hit, then run again, ignoring one
6693 less than that number, and this will get you quickly to the last hit of
6696 * Ability to stop printing at NULL character
6698 "set print null-stop" will cause GDB to stop printing the characters of
6699 an array when the first NULL is encountered. This is useful when large
6700 arrays actually contain only short strings.
6702 * Shared library breakpoints
6704 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6705 breakpoints in shared libraries before the executable is run.
6707 * Hardware watchpoints
6709 There is a new hardware breakpoint for the watch command for sparclite
6710 targets. See gdb/sparclite/hw_breakpoint.note.
6712 Hardware watchpoints are also now supported under GNU/Linux.
6716 Annotations have been added. These are for use with graphical interfaces,
6717 and are still experimental. Currently only gdba.el uses these.
6719 * Improved Irix 5 support
6721 GDB now works properly with Irix 5.2.
6723 * Improved HPPA support
6725 GDB now works properly with the latest GCC and GAS.
6727 * New native configurations
6729 Sequent PTX4 i[34]86-sequent-ptx4
6730 HPPA running OSF/1 hppa*-*-osf*
6731 Atari TT running SVR4 m68*-*-sysv4*
6732 RS/6000 LynxOS rs6000-*-lynxos*
6736 OS/9000 i[34]86-*-os9k
6737 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6740 * Hitachi SH7000 and E7000-PC ICE support
6742 There is now support for communicating with the Hitachi E7000-PC ICE.
6743 This is available automatically when GDB is configured for the SH.
6747 As usual, a variety of small fixes and improvements, both generic
6748 and configuration-specific. See the ChangeLog for more detail.
6750 *** Changes in GDB-4.12:
6752 * Irix 5 is now supported
6756 GDB-4.12 on the HPPA has a number of changes which make it unable
6757 to debug the output from the currently released versions of GCC and
6758 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6759 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6760 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6763 *** Changes in GDB-4.11:
6765 * User visible changes:
6769 The "set remotedebug" option is now consistent between the mips remote
6770 target, remote targets using the gdb-specific protocol, UDI (AMD's
6771 debug protocol for the 29k) and the 88k bug monitor. It is now an
6772 integer specifying a debug level (normally 0 or 1, but 2 means more
6773 debugging info for the mips target).
6775 * DEC Alpha native support
6777 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6778 debug info, but GDB works fairly well with the DEC compiler and should
6779 work with a future GCC release. See the README file for a few
6780 Alpha-specific notes.
6782 * Preliminary thread implementation
6784 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6786 * LynxOS native and target support for 386
6788 This release has been hosted on LynxOS 2.2, and also can be configured
6789 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6792 * Improvements in C++ mangling/demangling.
6794 This release has much better g++ debugging, specifically in name
6795 mangling/demangling, virtual function calls, print virtual table,
6796 call methods, ...etc.
6798 *** Changes in GDB-4.10:
6800 * User visible changes:
6802 Remote debugging using the GDB-specific (`target remote') protocol now
6803 supports the `load' command. This is only useful if you have some
6804 other way of getting the stub to the target system, and you can put it
6805 somewhere in memory where it won't get clobbered by the download.
6807 Filename completion now works.
6809 When run under emacs mode, the "info line" command now causes the
6810 arrow to point to the line specified. Also, "info line" prints
6811 addresses in symbolic form (as well as hex).
6813 All vxworks based targets now support a user settable option, called
6814 vxworks-timeout. This option represents the number of seconds gdb
6815 should wait for responses to rpc's. You might want to use this if
6816 your vxworks target is, perhaps, a slow software simulator or happens
6817 to be on the far side of a thin network line.
6821 This release contains support for using a DEC alpha as a GDB host for
6822 cross debugging. Native alpha debugging is not supported yet.
6825 *** Changes in GDB-4.9:
6829 This is the first GDB release which is accompanied by a matching testsuite.
6830 The testsuite requires installation of dejagnu, which should be available
6831 via ftp from most sites that carry GNU software.
6835 'Cfront' style demangling has had its name changed to 'ARM' style, to
6836 emphasize that it was written from the specifications in the C++ Annotated
6837 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6838 disclaimers, it still generated too much confusion with users attempting to
6839 use gdb with AT&T cfront.
6843 GDB now uses a standard remote interface to a simulator library.
6844 So far, the library contains simulators for the Zilog Z8001/2, the
6845 Hitachi H8/300, H8/500 and Super-H.
6847 * New targets supported
6849 H8/300 simulator h8300-hitachi-hms or h8300hms
6850 H8/500 simulator h8500-hitachi-hms or h8500hms
6851 SH simulator sh-hitachi-hms or sh
6852 Z8000 simulator z8k-zilog-none or z8ksim
6853 IDT MIPS board over serial line mips-idt-ecoff
6855 Cross-debugging to GO32 targets is supported. It requires a custom
6856 version of the i386-stub.c module which is integrated with the
6857 GO32 memory extender.
6859 * New remote protocols
6861 MIPS remote debugging protocol.
6863 * New source languages supported
6865 This version includes preliminary support for Chill, a Pascal like language
6866 used by telecommunications companies. Chill support is also being integrated
6867 into the GNU compiler, but we don't know when it will be publically available.
6870 *** Changes in GDB-4.8:
6872 * HP Precision Architecture supported
6874 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6875 version of this support was available as a set of patches from the
6876 University of Utah. GDB does not support debugging of programs
6877 compiled with the HP compiler, because HP will not document their file
6878 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6879 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6881 Many problems in the preliminary version have been fixed.
6883 * Faster and better demangling
6885 We have improved template demangling and fixed numerous bugs in the GNU style
6886 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6887 character types (wchar_t) are now supported. Demangling of each symbol is now
6888 only done once, and is cached when the symbol table for a file is read in.
6889 This results in a small increase in memory usage for C programs, a moderate
6890 increase in memory usage for C++ programs, and a fantastic speedup in
6893 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6894 from the specifications in the Annotated Reference Manual, which AT&T's
6895 compiler does not actually implement.
6897 * G++ multiple inheritance compiler problem
6899 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6900 inheritance lattices was reworked to properly discover ambiguities. We
6901 recently found an example which causes this new algorithm to fail in a
6902 very subtle way, producing bad debug information for those classes.
6903 The file 'gcc.patch' (in this directory) can be applied to gcc to
6904 circumvent the problem. A future GCC release will contain a complete
6907 The previous G++ debug info problem (mentioned below for the gdb-4.7
6908 release) is fixed in gcc version 2.3.2.
6910 * Improved configure script
6912 The `configure' script will now attempt to guess your system type if
6913 you don't supply a host system type. The old scheme of supplying a
6914 host system triplet is preferable over using this. All the magic is
6915 done in the new `config.guess' script. Examine it for details.
6917 We have also brought our configure script much more in line with the FSF's
6918 version. It now supports the --with-xxx options. In particular,
6919 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6920 The resulting GDB will not be able to read arbitrary object file formats --
6921 only the format ``expected'' to be used on the configured target system.
6922 We hope to make this the default in a future release.
6924 * Documentation improvements
6926 There's new internal documentation on how to modify GDB, and how to
6927 produce clean changes to the code. We implore people to read it
6928 before submitting changes.
6930 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6931 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6932 `info' files are also provided. To build `info' files from scratch,
6933 you will need the latest `makeinfo' release, which will be available in
6934 a future texinfo-X.Y release.
6936 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6937 We're not sure exactly which versions have this problem, but it has
6938 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6939 or better. If that isn't possible, there is a patch in
6940 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6941 around this problem.
6945 GDB now supports array constants that can be used in expressions typed in by
6946 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6947 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6950 The new directory `gdb/sparclite' contains a program that demonstrates
6951 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6953 * New native hosts supported
6955 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6956 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6958 * New targets supported
6960 AMD 29k family via UDI a29k-amd-udi or udi29k
6962 * New file formats supported
6964 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6965 HPUX core files, and SCO 3.2v2 core files.
6969 Attaching to processes now works again; thanks for the many bug reports.
6971 We have also stomped on a bunch of core dumps caused by
6972 printf_filtered("%s") problems.
6974 We eliminated a copyright problem on the rpc and ptrace header files
6975 for VxWorks, which was discovered at the last minute during the 4.7
6976 release. You should now be able to build a VxWorks GDB.
6978 You can now interrupt gdb while an attached process is running. This
6979 will cause the attached process to stop, and give control back to GDB.
6981 We fixed problems caused by using too many file descriptors
6982 for reading symbols from object files and libraries. This was
6983 especially a problem for programs that used many (~100) shared
6986 The `step' command now only enters a subroutine if there is line number
6987 information for the subroutine. Otherwise it acts like the `next'
6988 command. Previously, `step' would enter subroutines if there was
6989 any debugging information about the routine. This avoids problems
6990 when using `cc -g1' on MIPS machines.
6992 * Internal improvements
6994 GDB's internal interfaces have been improved to make it easier to support
6995 debugging of multiple languages in the future.
6997 GDB now uses a common structure for symbol information internally.
6998 Minimal symbols (derived from linkage symbols in object files), partial
6999 symbols (from a quick scan of debug information), and full symbols
7000 contain a common subset of information, making it easier to write
7001 shared code that handles any of them.
7003 * New command line options
7005 We now accept --silent as an alias for --quiet.
7009 The memory-mapped-malloc library is now licensed under the GNU Library
7010 General Public License.
7012 *** Changes in GDB-4.7:
7014 * Host/native/target split
7016 GDB has had some major internal surgery to untangle the support for
7017 hosts and remote targets. Now, when you configure GDB for a remote
7018 target, it will no longer load in all of the support for debugging
7019 local programs on the host. When fully completed and tested, this will
7020 ensure that arbitrary host/target combinations are possible.
7022 The primary conceptual shift is to separate the non-portable code in
7023 GDB into three categories. Host specific code is required any time GDB
7024 is compiled on that host, regardless of the target. Target specific
7025 code relates to the peculiarities of the target, but can be compiled on
7026 any host. Native specific code is everything else: it can only be
7027 built when the host and target are the same system. Child process
7028 handling and core file support are two common `native' examples.
7030 GDB's use of /proc for controlling Unix child processes is now cleaner.
7031 It has been split out into a single module under the `target_ops' vector,
7032 plus two native-dependent functions for each system that uses /proc.
7034 * New hosts supported
7036 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7037 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7038 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7040 * New targets supported
7042 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7043 68030 and CPU32 m68030-*-*, m68332-*-*
7045 * New native hosts supported
7047 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7048 (386bsd is not well tested yet)
7049 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7051 * New file formats supported
7053 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7054 supports reading of `a.out.adobe' object files, which are an a.out
7055 format extended with minimal information about multiple sections.
7059 `show copying' is the same as the old `info copying'.
7060 `show warranty' is the same as `info warrantee'.
7061 These were renamed for consistency. The old commands continue to work.
7063 `info handle' is a new alias for `info signals'.
7065 You can now define pre-command hooks, which attach arbitrary command
7066 scripts to any command. The commands in the hook will be executed
7067 prior to the user's command. You can also create a hook which will be
7068 executed whenever the program stops. See gdb.texinfo.
7072 We now deal with Cfront style name mangling, and can even extract type
7073 info from mangled symbols. GDB can automatically figure out which
7074 symbol mangling style your C++ compiler uses.
7076 Calling of methods and virtual functions has been improved as well.
7080 The crash that occured when debugging Sun Ansi-C compiled binaries is
7081 fixed. This was due to mishandling of the extra N_SO stabs output
7084 We also finally got Ultrix 4.2 running in house, and fixed core file
7085 support, with help from a dozen people on the net.
7087 John M. Farrell discovered that the reason that single-stepping was so
7088 slow on all of the Mips based platforms (primarily SGI and DEC) was
7089 that we were trying to demangle and lookup a symbol used for internal
7090 purposes on every instruction that was being stepped through. Changing
7091 the name of that symbol so that it couldn't be mistaken for a C++
7092 mangled symbol sped things up a great deal.
7094 Rich Pixley sped up symbol lookups in general by getting much smarter
7095 about when C++ symbol mangling is necessary. This should make symbol
7096 completion (TAB on the command line) much faster. It's not as fast as
7097 we'd like, but it's significantly faster than gdb-4.6.
7101 A new user controllable variable 'call_scratch_address' can
7102 specify the location of a scratch area to be used when GDB
7103 calls a function in the target. This is necessary because the
7104 usual method of putting the scratch area on the stack does not work
7105 in systems that have separate instruction and data spaces.
7107 We integrated changes to support the 29k UDI (Universal Debugger
7108 Interface), but discovered at the last minute that we didn't have all
7109 of the appropriate copyright paperwork. We are working with AMD to
7110 resolve this, and hope to have it available soon.
7114 We have sped up the remote serial line protocol, especially for targets
7115 with lots of registers. It now supports a new `expedited status' ('T')
7116 message which can be used in place of the existing 'S' status message.
7117 This allows the remote stub to send only the registers that GDB
7118 needs to make a quick decision about single-stepping or conditional
7119 breakpoints, eliminating the need to fetch the entire register set for
7120 each instruction being stepped through.
7122 The GDB remote serial protocol now implements a write-through cache for
7123 registers, only re-reading the registers if the target has run.
7125 There is also a new remote serial stub for SPARC processors. You can
7126 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7127 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7128 processor with a serial port.
7132 Configure.in files have become much easier to read and modify. A new
7133 `table driven' format makes it more obvious what configurations are
7134 supported, and what files each one uses.
7138 There is a new opcodes library which will eventually contain all of the
7139 disassembly routines and opcode tables. At present, it only contains
7140 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7141 disassembler (binutils/objdump) to share these routines.
7143 The libiberty library is now copylefted under the GNU Library General
7144 Public License. This allows more liberal use, and was done so libg++
7145 can use it. This makes no difference to GDB, since the Library License
7146 grants all the rights from the General Public License.
7150 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7151 reference to the stabs symbol info used by the debugger. It is (as far
7152 as we know) the only published document on this fascinating topic. We
7153 encourage you to read it, compare it to the stabs information on your
7154 system, and send improvements on the document in general (to
7155 bug-gdb@prep.ai.mit.edu).
7157 And, of course, many bugs have been fixed.
7160 *** Changes in GDB-4.6:
7162 * Better support for C++ function names
7164 GDB now accepts as input the "demangled form" of C++ overloaded function
7165 names and member function names, and can do command completion on such names
7166 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7167 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7168 Make use of command completion, it is your friend.
7170 GDB also now accepts a variety of C++ mangled symbol formats. They are
7171 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7172 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7173 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7174 for the list of formats.
7176 * G++ symbol mangling problem
7178 Recent versions of gcc have a bug in how they emit debugging information for
7179 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7180 directory) can be applied to gcc to fix the problem. Alternatively, if you
7181 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7182 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7183 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7186 * New 'maintenance' command
7188 All of the commands related to hacking GDB internals have been moved out of
7189 the main command set, and now live behind the 'maintenance' command. This
7190 can also be abbreviated as 'mt'. The following changes were made:
7192 dump-me -> maintenance dump-me
7193 info all-breakpoints -> maintenance info breakpoints
7194 printmsyms -> maintenance print msyms
7195 printobjfiles -> maintenance print objfiles
7196 printpsyms -> maintenance print psymbols
7197 printsyms -> maintenance print symbols
7199 The following commands are new:
7201 maintenance demangle Call internal GDB demangler routine to
7202 demangle a C++ link name and prints the result.
7203 maintenance print type Print a type chain for a given symbol
7205 * Change to .gdbinit file processing
7207 We now read the $HOME/.gdbinit file before processing the argv arguments
7208 (e.g. reading symbol files or core files). This allows global parameters to
7209 be set, which will apply during the symbol reading. The ./.gdbinit is still
7210 read after argv processing.
7212 * New hosts supported
7214 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7216 GNU/Linux support i386-unknown-linux or linux
7218 We are also including code to support the HP/PA running BSD and HPUX. This
7219 is almost guaranteed not to work, as we didn't have time to test or build it
7220 for this release. We are including it so that the more adventurous (or
7221 masochistic) of you can play with it. We also had major problems with the
7222 fact that the compiler that we got from HP doesn't support the -g option.
7225 * New targets supported
7227 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7229 * More smarts about finding #include files
7231 GDB now remembers the compilation directory for all include files, and for
7232 all files from which C is generated (like yacc and lex sources). This
7233 greatly improves GDB's ability to find yacc/lex sources, and include files,
7234 especially if you are debugging your program from a directory different from
7235 the one that contains your sources.
7237 We also fixed a bug which caused difficulty with listing and setting
7238 breakpoints in include files which contain C code. (In the past, you had to
7239 try twice in order to list an include file that you hadn't looked at before.)
7241 * Interesting infernals change
7243 GDB now deals with arbitrary numbers of sections, where the symbols for each
7244 section must be relocated relative to that section's landing place in the
7245 target's address space. This work was needed to support ELF with embedded
7246 stabs used by Solaris-2.0.
7248 * Bug fixes (of course!)
7250 There have been loads of fixes for the following things:
7251 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7252 i960, stabs, DOS(GO32), procfs, etc...
7254 See the ChangeLog for details.
7256 *** Changes in GDB-4.5:
7258 * New machines supported (host and target)
7260 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7262 SGI Irix-4.x mips-sgi-irix4 or iris4
7264 * New malloc package
7266 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7267 Mmalloc is capable of handling mutiple heaps of memory. It is also
7268 capable of saving a heap to a file, and then mapping it back in later.
7269 This can be used to greatly speedup the startup of GDB by using a
7270 pre-parsed symbol table which lives in a mmalloc managed heap. For
7271 more details, please read mmalloc/mmalloc.texi.
7275 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7276 'help info proc' for details.
7278 * MIPS ecoff symbol table format
7280 The code that reads MIPS symbol table format is now supported on all hosts.
7281 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7284 * File name changes for MS-DOS
7286 Many files in the config directories have been renamed to make it easier to
7287 support GDB on MS-DOSe systems (which have very restrictive file name
7288 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7289 environment) is close to working but has some remaining problems. Note
7290 that debugging of DOS programs is not supported, due to limitations
7291 in the ``operating system'', but it can be used to host cross-debugging.
7293 * Cross byte order fixes
7295 Many fixes have been made to support cross debugging of Sparc and MIPS
7296 targets from hosts whose byte order differs.
7298 * New -mapped and -readnow options
7300 If memory-mapped files are available on your system through the 'mmap'
7301 system call, you can use the -mapped option on the `file' or
7302 `symbol-file' commands to cause GDB to write the symbols from your
7303 program into a reusable file. If the program you are debugging is
7304 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7305 Future GDB debugging sessions will notice the presence of this file,
7306 and will quickly map in symbol information from it, rather than reading
7307 the symbol table from the executable program. Using the '-mapped'
7308 option in a GDB `file' or `symbol-file' command has the same effect as
7309 starting GDB with the '-mapped' command-line option.
7311 You can cause GDB to read the entire symbol table immediately by using
7312 the '-readnow' option with any of the commands that load symbol table
7313 information (or on the GDB command line). This makes the command
7314 slower, but makes future operations faster.
7316 The -mapped and -readnow options are typically combined in order to
7317 build a `fred.syms' file that contains complete symbol information.
7318 A simple GDB invocation to do nothing but build a `.syms' file for future
7321 gdb -batch -nx -mapped -readnow programname
7323 The `.syms' file is specific to the host machine on which GDB is run.
7324 It holds an exact image of GDB's internal symbol table. It cannot be
7325 shared across multiple host platforms.
7327 * longjmp() handling
7329 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7330 siglongjmp() without losing control. This feature has not yet been ported to
7331 all systems. It currently works on many 386 platforms, all MIPS-based
7332 platforms (SGI, DECstation, etc), and Sun3/4.
7336 Preliminary work has been put in to support the new Solaris OS from Sun. At
7337 this time, it can control and debug processes, but it is not capable of
7342 As always, many many bug fixes. The major areas were with g++, and mipsread.
7343 People using the MIPS-based platforms should experience fewer mysterious
7344 crashes and trashed symbol tables.
7346 *** Changes in GDB-4.4:
7348 * New machines supported (host and target)
7350 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7352 BSD Reno on Vax vax-dec-bsd
7353 Ultrix on Vax vax-dec-ultrix
7355 * New machines supported (target)
7357 AMD 29000 embedded, using EBMON a29k-none-none
7361 GDB continues to improve its handling of C++. `References' work better.
7362 The demangler has also been improved, and now deals with symbols mangled as
7363 per the Annotated C++ Reference Guide.
7365 GDB also now handles `stabs' symbol information embedded in MIPS
7366 `ecoff' symbol tables. Since the ecoff format was not easily
7367 extensible to handle new languages such as C++, this appeared to be a
7368 good way to put C++ debugging info into MIPS binaries. This option
7369 will be supported in the GNU C compiler, version 2, when it is
7372 * New features for SVR4
7374 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7375 shared libraries. Debugging dynamically linked programs should present
7376 only minor differences from debugging statically linked programs.
7378 The `info proc' command will print out information about any process
7379 on an SVR4 system (including the one you are debugging). At the moment,
7380 it prints the address mappings of the process.
7382 If you bring up GDB on another SVR4 system, please send mail to
7383 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7385 * Better dynamic linking support in SunOS
7387 Reading symbols from shared libraries which contain debugging symbols
7388 now works properly. However, there remain issues such as automatic
7389 skipping of `transfer vector' code during function calls, which
7390 make it harder to debug code in a shared library, than to debug the
7391 same code linked statically.
7395 GDB is now using the latest `getopt' routines from the FSF. This
7396 version accepts the -- prefix for options with long names. GDB will
7397 continue to accept the old forms (-option and +option) as well.
7398 Various single letter abbreviations for options have been explicity
7399 added to the option table so that they won't get overshadowed in the
7400 future by other options that begin with the same letter.
7404 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7405 Many assorted bugs have been handled. Many more remain to be handled.
7406 See the various ChangeLog files (primarily in gdb and bfd) for details.
7409 *** Changes in GDB-4.3:
7411 * New machines supported (host and target)
7413 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7414 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7415 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7417 * Almost SCO Unix support
7419 We had hoped to support:
7420 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7421 (except for core file support), but we discovered very late in the release
7422 that it has problems with process groups that render gdb unusable. Sorry
7423 about that. I encourage people to fix it and post the fixes.
7425 * Preliminary ELF and DWARF support
7427 GDB can read ELF object files on System V Release 4, and can handle
7428 debugging records for C, in DWARF format, in ELF files. This support
7429 is preliminary. If you bring up GDB on another SVR4 system, please
7430 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7435 GDB now uses the latest `readline' library. One user-visible change
7436 is that two tabs will list possible command completions, which previously
7437 required typing M-? (meta-question mark, or ESC ?).
7441 The `stepi' bug that many of you noticed has been squashed.
7442 Many bugs in C++ have been handled. Many more remain to be handled.
7443 See the various ChangeLog files (primarily in gdb and bfd) for details.
7445 * State of the MIPS world (in case you wondered):
7447 GDB can understand the symbol tables emitted by the compilers
7448 supplied by most vendors of MIPS-based machines, including DEC. These
7449 symbol tables are in a format that essentially nobody else uses.
7451 Some versions of gcc come with an assembler post-processor called
7452 mips-tfile. This program is required if you want to do source-level
7453 debugging of gcc-compiled programs. I believe FSF does not ship
7454 mips-tfile with gcc version 1, but it will eventually come with gcc
7457 Debugging of g++ output remains a problem. g++ version 1.xx does not
7458 really support it at all. (If you're lucky, you should be able to get
7459 line numbers and stack traces to work, but no parameters or local
7460 variables.) With some work it should be possible to improve the
7463 When gcc version 2 is released, you will have somewhat better luck.
7464 However, even then you will get confusing results for inheritance and
7467 We will eventually provide full debugging of g++ output on
7468 DECstations. This will probably involve some kind of stabs-in-ecoff
7469 encapulation, but the details have not been worked out yet.
7472 *** Changes in GDB-4.2:
7474 * Improved configuration
7476 Only one copy of `configure' exists now, and it is not self-modifying.
7477 Porting BFD is simpler.
7481 The `step' and `next' commands now only stop at the first instruction
7482 of a source line. This prevents the multiple stops that used to occur
7483 in switch statements, for-loops, etc. `Step' continues to stop if a
7484 function that has debugging information is called within the line.
7488 Lots of small bugs fixed. More remain.
7490 * New host supported (not target)
7492 Intel 386 PC clone running Mach i386-none-mach
7495 *** Changes in GDB-4.1:
7497 * Multiple source language support
7499 GDB now has internal scaffolding to handle several source languages.
7500 It determines the type of each source file from its filename extension,
7501 and will switch expression parsing and number formatting to match the
7502 language of the function in the currently selected stack frame.
7503 You can also specifically set the language to be used, with
7504 `set language c' or `set language modula-2'.
7508 GDB now has preliminary support for the GNU Modula-2 compiler,
7509 currently under development at the State University of New York at
7510 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7511 continue through the fall of 1991 and into 1992.
7513 Other Modula-2 compilers are currently not supported, and attempting to
7514 debug programs compiled with them will likely result in an error as the
7515 symbol table is read. Feel free to work on it, though!
7517 There are hooks in GDB for strict type checking and range checking,
7518 in the `Modula-2 philosophy', but they do not currently work.
7522 GDB can now write to executable and core files (e.g. patch
7523 a variable's value). You must turn this switch on, specify
7524 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7525 by assigning a new value to a variable. Modifications take
7528 * Automatic SunOS shared library reading
7530 When you run your program, GDB automatically determines where its
7531 shared libraries (if any) have been loaded, and reads their symbols.
7532 The `share' command is no longer needed. This also works when
7533 examining core files.
7537 You can specify the number of lines that the `list' command shows.
7540 * New machines supported (host and target)
7542 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7543 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7544 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7546 * New hosts supported (not targets)
7548 IBM RT/PC: romp-ibm-aix or rtpc
7550 * New targets supported (not hosts)
7552 AMD 29000 embedded with COFF a29k-none-coff
7553 AMD 29000 embedded with a.out a29k-none-aout
7554 Ultracomputer remote kernel debug a29k-nyu-kern
7556 * New remote interfaces
7562 *** Changes in GDB-4.0:
7566 Wide output is wrapped at good places to make the output more readable.
7568 Gdb now supports cross-debugging from a host machine of one type to a
7569 target machine of another type. Communication with the target system
7570 is over serial lines. The ``target'' command handles connecting to the
7571 remote system; the ``load'' command will download a program into the
7572 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7573 also supports debugging of realtime processes running under VxWorks,
7574 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7575 stub on the target system.
7577 New CPUs supported include the AMD 29000 and Intel 960.
7579 GDB now reads object files and symbol tables via a ``binary file''
7580 library, which allows a single copy of GDB to debug programs of multiple
7581 object file types such as a.out and coff.
7583 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7584 refcard.dvi and refcard.ps are available to format it).
7587 * Control-Variable user interface simplified
7589 All variables that control the operation of the debugger can be set
7590 by the ``set'' command, and displayed by the ``show'' command.
7592 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7593 ``Show prompt'' produces the response:
7594 Gdb's prompt is new-gdb=>.
7596 What follows are the NEW set commands. The command ``help set'' will
7597 print a complete list of old and new set commands. ``help set FOO''
7598 will give a longer description of the variable FOO. ``show'' will show
7599 all of the variable descriptions and their current settings.
7601 confirm on/off: Enables warning questions for operations that are
7602 hard to recover from, e.g. rerunning the program while
7603 it is already running. Default is ON.
7605 editing on/off: Enables EMACS style command line editing
7606 of input. Previous lines can be recalled with
7607 control-P, the current line can be edited with control-B,
7608 you can search for commands with control-R, etc.
7611 history filename NAME: NAME is where the gdb command history
7612 will be stored. The default is .gdb_history,
7613 or the value of the environment variable
7616 history size N: The size, in commands, of the command history. The
7617 default is 256, or the value of the environment variable
7620 history save on/off: If this value is set to ON, the history file will
7621 be saved after exiting gdb. If set to OFF, the
7622 file will not be saved. The default is OFF.
7624 history expansion on/off: If this value is set to ON, then csh-like
7625 history expansion will be performed on
7626 command line input. The default is OFF.
7628 radix N: Sets the default radix for input and output. It can be set
7629 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7630 in the current radix, so "set radix 10" is always a no-op.
7632 height N: This integer value is the number of lines on a page. Default
7633 is 24, the current `stty rows'' setting, or the ``li#''
7634 setting from the termcap entry matching the environment
7637 width N: This integer value is the number of characters on a line.
7638 Default is 80, the current `stty cols'' setting, or the ``co#''
7639 setting from the termcap entry matching the environment
7642 Note: ``set screensize'' is obsolete. Use ``set height'' and
7643 ``set width'' instead.
7645 print address on/off: Print memory addresses in various command displays,
7646 such as stack traces and structure values. Gdb looks
7647 more ``symbolic'' if you turn this off; it looks more
7648 ``machine level'' with it on. Default is ON.
7650 print array on/off: Prettyprint arrays. New convenient format! Default
7653 print demangle on/off: Print C++ symbols in "source" form if on,
7656 print asm-demangle on/off: Same, for assembler level printouts
7659 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7662 * Support for Epoch Environment.
7664 The epoch environment is a version of Emacs v18 with windowing. One
7665 new command, ``inspect'', is identical to ``print'', except that if you
7666 are running in the epoch environment, the value is printed in its own
7670 * Support for Shared Libraries
7672 GDB can now debug programs and core files that use SunOS shared libraries.
7673 Symbols from a shared library cannot be referenced
7674 before the shared library has been linked with the program (this
7675 happens after you type ``run'' and before the function main() is entered).
7676 At any time after this linking (including when examining core files
7677 from dynamically linked programs), gdb reads the symbols from each
7678 shared library when you type the ``sharedlibrary'' command.
7679 It can be abbreviated ``share''.
7681 sharedlibrary REGEXP: Load shared object library symbols for files
7682 matching a unix regular expression. No argument
7683 indicates to load symbols for all shared libraries.
7685 info sharedlibrary: Status of loaded shared libraries.
7690 A watchpoint stops execution of a program whenever the value of an
7691 expression changes. Checking for this slows down execution
7692 tremendously whenever you are in the scope of the expression, but is
7693 quite useful for catching tough ``bit-spreader'' or pointer misuse
7694 problems. Some machines such as the 386 have hardware for doing this
7695 more quickly, and future versions of gdb will use this hardware.
7697 watch EXP: Set a watchpoint (breakpoint) for an expression.
7699 info watchpoints: Information about your watchpoints.
7701 delete N: Deletes watchpoint number N (same as breakpoints).
7702 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7703 enable N: Re-enables watchpoint number N (same as breakpoints).
7706 * C++ multiple inheritance
7708 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7711 * C++ exception handling
7713 Gdb now supports limited C++ exception handling. Besides the existing
7714 ability to breakpoint on an exception handler, gdb can breakpoint on
7715 the raising of an exception (before the stack is peeled back to the
7718 catch FOO: If there is a FOO exception handler in the dynamic scope,
7719 set a breakpoint to catch exceptions which may be raised there.
7720 Multiple exceptions (``catch foo bar baz'') may be caught.
7722 info catch: Lists all exceptions which may be caught in the
7723 current stack frame.
7726 * Minor command changes
7728 The command ``call func (arg, arg, ...)'' now acts like the print
7729 command, except it does not print or save a value if the function's result
7730 is void. This is similar to dbx usage.
7732 The ``up'' and ``down'' commands now always print the frame they end up
7733 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7734 frames without printing.
7736 * New directory command
7738 'dir' now adds directories to the FRONT of the source search path.
7739 The path starts off empty. Source files that contain debug information
7740 about the directory in which they were compiled can be found even
7741 with an empty path; Sun CC and GCC include this information. If GDB can't
7742 find your source file in the current directory, type "dir .".
7744 * Configuring GDB for compilation
7746 For normal use, type ``./configure host''. See README or gdb.texinfo
7749 GDB now handles cross debugging. If you are remotely debugging between
7750 two different machines, type ``./configure host -target=targ''.
7751 Host is the machine where GDB will run; targ is the machine
7752 where the program that you are debugging will run.