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 maint set test-settings KIND
173 maint show test-settings KIND
174 A set of commands used by the testsuite for exercising the settings
177 maint set tui-resize-message [on|off]
178 maint show tui-resize-message
179 Control whether GDB prints a message each time the terminal is
180 resized when in TUI mode. This is primarily useful for testing the
183 set print frame-info [short-location|location|location-and-address
184 |source-and-location|source-line|auto]
185 show print frame-info
186 This controls what frame information is printed by the commands printing
187 a frame. This setting will e.g. influence the behaviour of 'backtrace',
188 'frame', 'stepi'. The python frame filtering also respect this setting.
189 The 'backtrace' '-frame-info' option can override this global setting.
191 info modules [-q] [REGEXP]
192 Return a list of Fortran modules matching REGEXP, or all modules if
195 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
196 Return a list of functions within all modules, grouped by module.
197 The list of functions can be restricted with the optional regular
198 expressions. MODULE_REGEXP matches against the module name,
199 TYPE_REGEXP matches against the function type signature, and REGEXP
200 matches against the function name.
202 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
203 Return a list of variables within all modules, grouped by module.
204 The list of variables can be restricted with the optional regular
205 expressions. MODULE_REGEXP matches against the module name,
206 TYPE_REGEXP matches against the variable type, and REGEXP matches
207 against the variable name.
209 set debug remote-packet-max-chars
210 show debug remote-packet-max-chars
211 Controls the number of characters to output in a remote packet when using
213 The default is 512 bytes.
218 The "help" command uses the title style to enhance the
219 readibility of its output by styling the classes and
223 Similarly to "help", the "apropos" command also uses the
224 title style for the command names. "apropos" accepts now
225 a flag "-v" (verbose) to show the full documentation
226 of matching commands and to use the highlight style to mark
227 the documentation parts matching REGEXP.
231 The GDB printf and eval commands can now print C-style and Ada-style
232 string convenience variables without calling functions in the program.
233 This allows to do formatted printing of strings without having
234 a running inferior, or when debugging a core dump.
236 info sources [-dirname | -basename] [--] [REGEXP]
237 This command has now optional arguments to only print the files
238 whose names match REGEXP. The arguments -dirname and -basename
239 allow to restrict matching respectively to the dirname and basename
243 The "show style" and its subcommands are now styling
244 a style name in their output using its own style, to help
245 the user visualize the different styles.
247 set print frame-arguments
248 The new value 'presence' indicates to only indicate the presence of
249 arguments using ..., instead of printing argument names and values.
251 set print raw-frame-arguments
252 show print raw-frame-arguments
254 These commands replace the similarly-named "set/show print raw
255 frame-arguments" commands (now with a dash instead of a space). The
256 old commands are now deprecated and may be removed in a future
259 maint test-options require-delimiter
260 maint test-options unknown-is-error
261 maint test-options unknown-is-operand
262 maint show test-options-completion-result
263 Commands used by the testsuite to validate the command options
266 focus, winheight, +, -, >, <
267 These commands are now case-sensitive.
269 * New command options, command completion
271 GDB now has a standard infrastructure to support dash-style command
272 options ('-OPT'). One benefit is that commands that use it can
273 easily support completion of command line arguments. Try "CMD
274 -[TAB]" or "help CMD" to find options supported by a command. Over
275 time, we intend to migrate most commands to this infrastructure. A
276 number of commands got support for new command options in this
279 ** The "print" and "compile print" commands now support a number of
280 options that allow overriding relevant global print settings as
281 set by "set print" subcommands:
285 -array-indexes [on|off]
286 -elements NUMBER|unlimited
290 -repeats NUMBER|unlimited
291 -static-members [on|off]
296 Note that because the "print"/"compile print" commands accept
297 arbitrary expressions which may look like options (including
298 abbreviations), if you specify any command option, then you must
299 use a double dash ("--") to mark the end of argument processing.
301 ** The "backtrace" command now supports a number of options that
302 allow overriding relevant global print settings as set by "set
303 backtrace" and "set print" subcommands:
305 -entry-values no|only|preferred|if-needed|both|compact|default
306 -frame-arguments all|scalars|none
307 -raw-frame-arguments [on|off]
308 -frame-info auto|source-line|location|source-and-location
309 |location-and-address|short-location
313 In addition, the full/no-filters/hide qualifiers are now also
314 exposed as command options too:
320 ** The "frame apply", "tfaas" and "faas" commands similarly now
321 support the following options:
326 ** The new "info sources" options -dirname and -basename options
327 are using the standard '-OPT' infrastructure.
329 All options above can also be abbreviated. The argument of boolean
330 (on/off) options can be 0/1 too, and also the argument is assumed
331 "on" if omitted. This allows writing compact command invocations,
334 (gdb) p -r -p -o 0 -- *myptr
336 The above is equivalent to:
338 (gdb) print -raw -pretty -object off -- *myptr
340 ** The "info types" command now supports the '-q' flag to disable
341 printing of some header information in a similar fashion to "info
342 variables" and "info functions".
344 ** The "info variables", "info functions", and "whereis" commands
345 now take a '-n' flag that excludes non-debug symbols (symbols
346 from the symbol table, not from the debug info such as DWARF)
349 * Completion improvements
351 ** GDB can now complete the options of the "thread apply all" and
352 "taas" commands, and their "-ascending" option can now be
355 ** GDB can now complete the options of the "info threads", "info
356 functions", "info variables", "info locals", and "info args"
359 ** GDB can now complete the options of the "compile file" and
360 "compile code" commands. The "compile file" command now
361 completes on filenames.
363 ** GDB can now complete the backtrace command's
364 "full/no-filters/hide" qualifiers.
366 * In settings, you can now abbreviate "unlimited".
368 E.g., "set print elements u" is now equivalent to "set print
374 This lists all the possible completions for the rest of the line, if it
375 were to be given as a command itself. This is intended for use by MI
376 frontends in cases when separate CLI and MI channels cannot be used.
378 -catch-throw, -catch-rethrow, and -catch-catch
379 These can be used to catch C++ exceptions in a similar fashion to
380 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
382 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
383 These commands are the MI equivalent of the CLI commands 'info
384 functions', 'info types', and 'info variables' respectively.
386 -symbol-info-modules, this is the MI equivalent of the CLI 'info
391 ** The default version of the MI interpreter is now 3 (-i=mi3).
393 ** The output of information about multi-location breakpoints (which is
394 syntactically incorrect in MI 2) has changed in MI 3. This affects
395 the following commands and events:
399 - =breakpoint-created
400 - =breakpoint-modified
402 The -fix-multi-location-breakpoint-output command can be used to enable
403 this behavior with previous MI versions.
405 ** Backtraces and frames include a new optional field addr_flags which is
406 given after the addr field. On AArch64 this contains PAC if the address
407 has been masked in the frame. On all other targets the field is not
412 The testsuite now creates the files gdb.cmd (containing the arguments
413 used to launch GDB) and gdb.in (containing all the commands sent to
414 GDB) in the output directory for each test script. Multiple invocations
415 are appended with .1, .2, .3 etc.
417 * Building GDB and GDBserver now requires GNU make >= 3.82.
419 Using another implementation of the make program or an earlier version of
420 GNU make to build GDB or GDBserver is not supported.
422 * Building GDB now requires GNU readline >= 7.0.
424 GDB now bundles GNU readline 8.0, but if you choose to use
425 --with-system-readline, only readline >= 7.0 can be used.
427 * The TUI SingleKey keymap is now named "SingleKey". This can be used
428 from .inputrc to bind keys in this keymap. This feature is only
429 available when gdb is built against GNU readline 8.0 or later.
431 * Removed targets and native configurations
433 GDB no longer supports debugging the Cell Broadband Engine. This includes
434 both debugging standalone Cell/B.E. SPU applications and integrated debugging
435 of Cell/B.E. applications that use both the PPU and SPU architectures.
441 * Removed targets and native configurations
443 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
446 *** Changes in GDB 8.3
448 * GDB and GDBserver now support access to additional registers on
449 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
452 * GDB now has experimental support for the compilation and injection of
453 C++ source code into the inferior. This beta release does not include
454 support for several language features, such as templates, constructors,
457 This feature requires GCC 7.1 or higher built with libcp1.so
460 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
461 can be passed using the '[ADDRESS]:PORT' notation, or the regular
462 'ADDRESS:PORT' method.
464 * DWARF index cache: GDB can now automatically save indices of DWARF
465 symbols on disk to speed up further loading of the same binaries.
467 * Ada task switching is now supported on aarch64-elf targets when
468 debugging a program using the Ravenscar Profile. For more information,
469 see the "Tasking Support when using the Ravenscar Profile" section
470 in the GDB user manual.
472 * GDB in batch mode now exits with status 1 if the last command to be
475 * The RISC-V target now supports target descriptions.
477 * System call catchpoints now support system call aliases on FreeBSD.
478 When the ABI of a system call changes in FreeBSD, this is
479 implemented by leaving a compatibility system call using the old ABI
480 at the existing number and allocating a new system call number for
481 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
482 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
483 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
484 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
485 so that a system call catchpoint for the 'kevent' system call will
486 catch invocations of both the 'kevent' and 'freebsd11_kevent'
487 binaries. This ensures that 'kevent' system calls are caught for
488 binaries using either the old or new ABIs.
490 * Terminal styling is now available for the CLI and the TUI. GNU
491 Source Highlight can additionally be used to provide styling of
492 source code snippets. See the "set style" commands, below, for more
495 * Removed support for old demangling styles arm, edg, gnu, hp and
500 set debug compile-cplus-types
501 show debug compile-cplus-types
502 Control the display of debug output about type conversion in the
503 C++ compile feature. Commands have no effect while compiliong
508 Control whether debug output about files/functions skipping is
511 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
512 Apply a command to some frames.
513 FLAG arguments allow to control what output to produce and how to handle
514 errors raised when applying COMMAND to a frame.
517 Apply a command to all threads (ignoring errors and empty output).
518 Shortcut for 'thread apply all -s COMMAND'.
521 Apply a command to all frames (ignoring errors and empty output).
522 Shortcut for 'frame apply all -s COMMAND'.
525 Apply a command to all frames of all threads (ignoring errors and empty
527 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
529 maint set dwarf unwinders (on|off)
530 maint show dwarf unwinders
531 Control whether DWARF unwinders can be used.
534 Display a list of open files for a process.
538 Changes to the "frame", "select-frame", and "info frame" CLI commands.
539 These commands all now take a frame specification which
540 is either a frame level, or one of the keywords 'level', 'address',
541 'function', or 'view' followed by a parameter. Selecting a frame by
542 address, or viewing a frame outside the current backtrace now
543 requires the use of a keyword. Selecting a frame by level is
544 unchanged. The MI comment "-stack-select-frame" is unchanged.
546 target remote FILENAME
547 target extended-remote FILENAME
548 If FILENAME is a Unix domain socket, GDB will attempt to connect
549 to this socket instead of opening FILENAME as a character device.
551 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
552 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
553 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
554 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
555 These commands can now print only the searched entities
556 matching the provided regexp(s), giving a condition
557 on the entity names or entity types. The flag -q disables
558 printing headers or informations messages.
564 These commands now determine the syntax for the shown entities
565 according to the language chosen by `set language'. In particular,
566 `set language auto' means to automatically choose the language of
569 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
570 The 'thread apply' command accepts new FLAG arguments.
571 FLAG arguments allow to control what output to produce and how to handle
572 errors raised when applying COMMAND to a thread.
574 set tui tab-width NCHARS
575 show tui tab-width NCHARS
576 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
578 set style enabled [on|off]
580 Enable or disable terminal styling. Styling is enabled by default
581 on most hosts, but disabled by default when in batch mode.
583 set style sources [on|off]
585 Enable or disable source code styling. Source code styling is
586 enabled by default, but only takes effect if styling in general is
587 enabled, and if GDB was linked with GNU Source Highlight.
589 set style filename foreground COLOR
590 set style filename background COLOR
591 set style filename intensity VALUE
592 Control the styling of file names.
594 set style function foreground COLOR
595 set style function background COLOR
596 set style function intensity VALUE
597 Control the styling of function names.
599 set style variable foreground COLOR
600 set style variable background COLOR
601 set style variable intensity VALUE
602 Control the styling of variable names.
604 set style address foreground COLOR
605 set style address background COLOR
606 set style address intensity VALUE
607 Control the styling of addresses.
611 ** The '-data-disassemble' MI command now accepts an '-a' option to
612 disassemble the whole function surrounding the given program
613 counter value or function name. Support for this feature can be
614 verified by using the "-list-features" command, which should
615 contain "data-disassemble-a-option".
617 ** Command responses and notifications that include a frame now include
618 the frame's architecture in a new "arch" attribute.
620 * New native configurations
622 GNU/Linux/RISC-V riscv*-*-linux*
623 FreeBSD/riscv riscv*-*-freebsd*
627 GNU/Linux/RISC-V riscv*-*-linux*
629 CSKY GNU/LINUX csky*-*-linux
630 FreeBSD/riscv riscv*-*-freebsd*
632 GNU/Linux/OpenRISC or1k*-*-linux*
636 GDB no longer supports native debugging on versions of MS-Windows
641 ** GDB no longer supports Python versions less than 2.6.
643 ** The gdb.Inferior type has a new 'progspace' property, which is the program
644 space associated to that inferior.
646 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
647 of objfiles associated to that program space.
649 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
650 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
653 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
654 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
655 correct and did not work properly.
657 ** The gdb.Value type has a new constructor, which is used to construct a
658 gdb.Value from a Python buffer object and a gdb.Type.
664 Enable or disable the undefined behavior sanitizer. This is
665 disabled by default, but passing --enable-ubsan=yes or
666 --enable-ubsan=auto to configure will enable it. Enabling this can
667 cause a performance penalty. The undefined behavior sanitizer was
668 first introduced in GCC 4.9.
670 *** Changes in GDB 8.2
672 * The 'set disassembler-options' command now supports specifying options
675 * The 'symbol-file' command now accepts an '-o' option to add a relative
676 offset to all sections.
678 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
679 a relative offset to all sections, but it allows to override the load
680 address of individual sections using '-s'.
682 * The 'add-symbol-file' command no longer requires the second argument
683 (address of the text section).
685 * The endianness used with the 'set endian auto' mode in the absence of
686 an executable selected for debugging is now the last endianness chosen
687 either by one of the 'set endian big' and 'set endian little' commands
688 or by inferring from the last executable used, rather than the startup
691 * The pager now allows a "c" response, meaning to disable the pager
692 for the rest of the current command.
694 * The commands 'info variables/functions/types' now show the source line
695 numbers of symbol definitions when available.
697 * 'info proc' now works on running processes on FreeBSD systems and core
698 files created on FreeBSD systems.
700 * C expressions can now use _Alignof, and C++ expressions can now use
703 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
704 the vector length while the process is running.
710 Control display of debugging info regarding the FreeBSD native target.
712 set|show varsize-limit
713 This new setting allows the user to control the maximum size of Ada
714 objects being printed when those objects have a variable type,
715 instead of that maximum size being hardcoded to 65536 bytes.
717 set|show record btrace cpu
718 Controls the processor to be used for enabling errata workarounds for
721 maint check libthread-db
722 Run integrity checks on the current inferior's thread debugging
725 maint set check-libthread-db (on|off)
726 maint show check-libthread-db
727 Control whether to run integrity checks on inferior specific thread
728 debugging libraries as they are loaded. The default is not to
733 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
735 ** The commands attached to a breakpoint can be set by assigning to
736 the breakpoint's "commands" field.
738 ** gdb.execute can now execute multi-line gdb commands.
740 ** The new functions gdb.convenience_variable and
741 gdb.set_convenience_variable can be used to get and set the value
742 of convenience variables.
744 ** A gdb.Parameter will no longer print the "set" help text on an
745 ordinary "set"; instead by default a "set" will be silent unless
746 the get_set_string method returns a non-empty string.
750 RiscV ELF riscv*-*-elf
752 * Removed targets and native configurations
754 m88k running OpenBSD m88*-*-openbsd*
755 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
756 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
757 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
759 * Aarch64/Linux hardware watchpoints improvements
761 Hardware watchpoints on unaligned addresses are now properly
762 supported when running Linux kernel 4.10 or higher: read and access
763 watchpoints are no longer spuriously missed, and all watchpoints
764 lengths between 1 and 8 bytes are supported. On older kernels,
765 watchpoints set on unaligned addresses are no longer missed, with
766 the tradeoff that there is a possibility of false hits being
771 --enable-codesign=CERT
772 This can be used to invoke "codesign -s CERT" after building gdb.
773 This option is useful on macOS, where code signing is required for
774 gdb to work properly.
776 --disable-gdbcli has been removed
777 This is now silently accepted, but does nothing.
779 *** Changes in GDB 8.1
781 * GDB now supports dynamically creating arbitrary register groups specified
782 in XML target descriptions. This allows for finer grain grouping of
783 registers on systems with a large amount of registers.
785 * The 'ptype' command now accepts a '/o' flag, which prints the
786 offsets and sizes of fields in a struct, like the pahole(1) tool.
788 * New "--readnever" command line option instructs GDB to not read each
789 symbol file's symbolic debug information. This makes startup faster
790 but at the expense of not being able to perform symbolic debugging.
791 This option is intended for use cases where symbolic debugging will
792 not be used, e.g., when you only need to dump the debuggee's core.
794 * GDB now uses the GNU MPFR library, if available, to emulate target
795 floating-point arithmetic during expression evaluation when the target
796 uses different floating-point formats than the host. At least version
797 3.1 of GNU MPFR is required.
799 * GDB now supports access to the guarded-storage-control registers and the
800 software-based guarded-storage broadcast control registers on IBM z14.
802 * On Unix systems, GDB now supports transmitting environment variables
803 that are to be set or unset to GDBserver. These variables will
804 affect the environment to be passed to the remote inferior.
806 To inform GDB of environment variables that are to be transmitted to
807 GDBserver, use the "set environment" command. Only user set
808 environment variables are sent to GDBserver.
810 To inform GDB of environment variables that are to be unset before
811 the remote inferior is started by the GDBserver, use the "unset
812 environment" command.
814 * Completion improvements
816 ** GDB can now complete function parameters in linespecs and
817 explicit locations without quoting. When setting breakpoints,
818 quoting around functions names to help with TAB-completion is
819 generally no longer necessary. For example, this now completes
822 (gdb) b function(in[TAB]
823 (gdb) b function(int)
825 Related, GDB is no longer confused with completing functions in
826 C++ anonymous namespaces:
829 (gdb) b (anonymous namespace)::[TAB][TAB]
830 (anonymous namespace)::a_function()
831 (anonymous namespace)::b_function()
833 ** GDB now has much improved linespec and explicit locations TAB
834 completion support, that better understands what you're
835 completing and offers better suggestions. For example, GDB no
836 longer offers data symbols as possible completions when you're
837 setting a breakpoint.
839 ** GDB now TAB-completes label symbol names.
841 ** The "complete" command now mimics TAB completion accurately.
843 * New command line options (gcore)
846 Dump all memory mappings.
848 * Breakpoints on C++ functions are now set on all scopes by default
850 By default, breakpoints on functions/methods are now interpreted as
851 specifying all functions with the given name ignoring missing
852 leading scopes (namespaces and classes).
854 For example, assuming a C++ program with symbols named:
859 both commands "break func()" and "break B::func()" set a breakpoint
862 You can use the new flag "-qualified" to override this. This makes
863 GDB interpret the specified function name as a complete
864 fully-qualified name instead. For example, using the same C++
865 program, the "break -q B::func" command sets a breakpoint on
866 "B::func", only. A parameter has been added to the Python
867 gdb.Breakpoint constructor to achieve the same result when creating
868 a breakpoint from Python.
870 * Breakpoints on functions marked with C++ ABI tags
872 GDB can now set breakpoints on functions marked with C++ ABI tags
873 (e.g., [abi:cxx11]). See here for a description of ABI tags:
874 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
876 Functions with a C++11 abi tag are demangled/displayed like this:
878 function[abi:cxx11](int)
881 You can now set a breakpoint on such functions simply as if they had
884 (gdb) b function(int)
886 Or if you need to disambiguate between tags, like:
888 (gdb) b function[abi:other_tag](int)
890 Tab completion was adjusted accordingly as well.
894 ** New events gdb.new_inferior, gdb.inferior_deleted, and
895 gdb.new_thread are emitted. See the manual for further
896 description of these.
898 ** A new function, "gdb.rbreak" has been added to the Python API.
899 This function allows the setting of a large number of breakpoints
900 via a regex pattern in Python. See the manual for further details.
902 ** Python breakpoints can now accept explicit locations. See the
903 manual for a further description of this feature.
906 * New features in the GDB remote stub, GDBserver
908 ** GDBserver is now able to start inferior processes with a
909 specified initial working directory.
911 The user can set the desired working directory to be used from
912 GDB using the new "set cwd" command.
914 ** New "--selftest" command line option runs some GDBserver self
915 tests. These self tests are disabled in releases.
917 ** On Unix systems, GDBserver now does globbing expansion and variable
918 substitution in inferior command line arguments.
920 This is done by starting inferiors using a shell, like GDB does.
921 See "set startup-with-shell" in the user manual for how to disable
922 this from GDB when using "target extended-remote". When using
923 "target remote", you can disable the startup with shell by using the
924 new "--no-startup-with-shell" GDBserver command line option.
926 ** On Unix systems, GDBserver now supports receiving environment
927 variables that are to be set or unset from GDB. These variables
928 will affect the environment to be passed to the inferior.
930 * When catching an Ada exception raised with a message, GDB now prints
931 the message in the catchpoint hit notification. In GDB/MI mode, that
932 information is provided as an extra field named "exception-message"
933 in the *stopped notification.
935 * Trait objects can now be inspected When debugging Rust code. This
936 requires compiler support which will appear in Rust 1.24.
940 QEnvironmentHexEncoded
941 Inform GDBserver of an environment variable that is to be passed to
942 the inferior when starting it.
945 Inform GDBserver of an environment variable that is to be unset
946 before starting the remote inferior.
949 Inform GDBserver that the environment should be reset (i.e.,
950 user-set environment variables should be unset).
953 Indicates whether the inferior must be started with a shell or not.
956 Tell GDBserver that the inferior to be started should use a specific
959 * The "maintenance print c-tdesc" command now takes an optional
960 argument which is the file name of XML target description.
962 * The "maintenance selftest" command now takes an optional argument to
963 filter the tests to be run.
965 * The "enable", and "disable" commands now accept a range of
966 breakpoint locations, e.g. "enable 1.3-5".
971 Set and show the current working directory for the inferior.
974 Set and show compilation command used for compiling and injecting code
975 with the 'compile' commands.
977 set debug separate-debug-file
978 show debug separate-debug-file
979 Control the display of debug output about separate debug file search.
981 set dump-excluded-mappings
982 show dump-excluded-mappings
983 Control whether mappings marked with the VM_DONTDUMP flag should be
984 dumped when generating a core file.
987 List the registered selftests.
990 Start the debugged program stopping at the first instruction.
993 Control display of debugging messages related to OpenRISC targets.
995 set|show print type nested-type-limit
996 Set and show the limit of nesting level for nested types that the
997 type printer will show.
999 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1002 * Safer/improved support for debugging with no debug info
1004 GDB no longer assumes functions with no debug information return
1007 This means that GDB now refuses to call such functions unless you
1008 tell it the function's type, by either casting the call to the
1009 declared return type, or by casting the function to a function
1010 pointer of the right type, and calling that:
1012 (gdb) p getenv ("PATH")
1013 'getenv' has unknown return type; cast the call to its declared return type
1014 (gdb) p (char *) getenv ("PATH")
1015 $1 = 0x7fffffffe "/usr/local/bin:/"...
1016 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1017 $2 = 0x7fffffffe "/usr/local/bin:/"...
1019 Similarly, GDB no longer assumes that global variables with no debug
1020 info have type 'int', and refuses to print the variable's value
1021 unless you tell it the variable's type:
1024 'var' has unknown type; cast it to its declared type
1028 * New native configurations
1030 FreeBSD/aarch64 aarch64*-*-freebsd*
1031 FreeBSD/arm arm*-*-freebsd*
1035 FreeBSD/aarch64 aarch64*-*-freebsd*
1036 FreeBSD/arm arm*-*-freebsd*
1037 OpenRISC ELF or1k*-*-elf
1039 * Removed targets and native configurations
1041 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1043 *** Changes in GDB 8.0
1045 * GDB now supports access to the PKU register on GNU/Linux. The register is
1046 added by the Memory Protection Keys for Userspace feature which will be
1047 available in future Intel CPUs.
1049 * GDB now supports C++11 rvalue references.
1053 ** New functions to start, stop and access a running btrace recording.
1054 ** Rvalue references are now supported in gdb.Type.
1056 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1059 * Building GDB and GDBserver now requires a C++11 compiler.
1061 For example, GCC 4.8 or later.
1063 It is no longer possible to build GDB or GDBserver with a C
1064 compiler. The --disable-build-with-cxx configure option has been
1067 * Building GDB and GDBserver now requires GNU make >= 3.81.
1069 It is no longer supported to build GDB or GDBserver with another
1070 implementation of the make program or an earlier version of GNU make.
1072 * Native debugging on MS-Windows supports command-line redirection
1074 Command-line arguments used for starting programs on MS-Windows can
1075 now include redirection symbols supported by native Windows shells,
1076 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1077 as "run", "start", and "set args", as well as the corresponding MI
1080 * Support for thread names on MS-Windows.
1082 GDB now catches and handles the special exception that programs
1083 running on MS-Windows use to assign names to threads in the
1086 * Support for Java programs compiled with gcj has been removed.
1088 * User commands now accept an unlimited number of arguments.
1089 Previously, only up to 10 was accepted.
1091 * The "eval" command now expands user-defined command arguments.
1093 This makes it easier to process a variable number of arguments:
1098 eval "print $arg%d", $i
1103 * Target descriptions can now describe registers for sparc32 and sparc64.
1105 * GDB now supports DWARF version 5 (debug information format).
1106 Its .debug_names index is not yet supported.
1108 * New native configurations
1110 FreeBSD/mips mips*-*-freebsd
1114 Synopsys ARC arc*-*-elf32
1115 FreeBSD/mips mips*-*-freebsd
1117 * Removed targets and native configurations
1119 Alpha running FreeBSD alpha*-*-freebsd*
1120 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1125 Erases all the flash memory regions reported by the target.
1127 maint print arc arc-instruction address
1128 Print internal disassembler information about instruction at a given address.
1132 set disassembler-options
1133 show disassembler-options
1134 Controls the passing of target specific information to the disassembler.
1135 If it is necessary to specify more than one disassembler option then
1136 multiple options can be placed together into a comma separated list.
1137 The default value is the empty string. Currently, the only supported
1138 targets are ARM, PowerPC and S/390.
1143 Erases all the flash memory regions reported by the target. This is
1144 equivalent to the CLI command flash-erase.
1146 -file-list-shared-libraries
1147 List the shared libraries in the program. This is
1148 equivalent to the CLI command "info shared".
1151 Catchpoints stopping the program when Ada exceptions are
1152 handled. This is equivalent to the CLI command "catch handlers".
1154 *** Changes in GDB 7.12
1156 * GDB and GDBserver now build with a C++ compiler by default.
1158 The --enable-build-with-cxx configure option is now enabled by
1159 default. One must now explicitly configure with
1160 --disable-build-with-cxx in order to build with a C compiler. This
1161 option will be removed in a future release.
1163 * GDBserver now supports recording btrace without maintaining an active
1166 * GDB now supports a negative repeat count in the 'x' command to examine
1167 memory backward from the given address. For example:
1170 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1171 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1172 (gdb) x/-5i 0x0000000000400580
1173 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1174 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1175 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1176 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1177 0x40057b <main(int, char**)+25>:
1178 callq 0x400536 <Func1(int, char const*)>
1180 * Fortran: Support structures with fields of dynamic types and
1181 arrays of dynamic types.
1183 * The symbol dumping maintenance commands have new syntax.
1184 maint print symbols [-pc address] [--] [filename]
1185 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1186 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1187 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1188 maint print msymbols [-objfile objfile] [--] [filename]
1190 * GDB now supports multibit bitfields and enums in target register
1193 * New Python-based convenience function $_as_string(val), which returns
1194 the textual representation of a value. This function is especially
1195 useful to obtain the text label of an enum value.
1197 * Intel MPX bound violation handling.
1199 Segmentation faults caused by a Intel MPX boundary violation
1200 now display the kind of violation (upper or lower), the memory
1201 address accessed and the memory bounds, along with the usual
1202 signal received and code location.
1206 Program received signal SIGSEGV, Segmentation fault
1207 Upper bound violation while accessing address 0x7fffffffc3b3
1208 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1209 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1211 * Rust language support.
1212 GDB now supports debugging programs written in the Rust programming
1213 language. See https://www.rust-lang.org/ for more information about
1216 * Support for running interpreters on specified input/output devices
1218 GDB now supports a new mechanism that allows frontends to provide
1219 fully featured GDB console views, as a better alternative to
1220 building such views on top of the "-interpreter-exec console"
1221 command. See the new "new-ui" command below. With that command,
1222 frontends can now start GDB in the traditional command-line mode
1223 running in an embedded terminal emulator widget, and create a
1224 separate MI interpreter running on a specified i/o device. In this
1225 way, GDB handles line editing, history, tab completion, etc. in the
1226 console all by itself, and the GUI uses the separate MI interpreter
1227 for its own control and synchronization, invisible to the command
1230 * The "catch syscall" command catches groups of related syscalls.
1232 The "catch syscall" command now supports catching a group of related
1233 syscalls using the 'group:' or 'g:' prefix.
1238 skip -gfile file-glob-pattern
1239 skip -function function
1240 skip -rfunction regular-expression
1241 A generalized form of the skip command, with new support for
1242 glob-style file names and regular expressions for function names.
1243 Additionally, a file spec and a function spec may now be combined.
1245 maint info line-table REGEXP
1246 Display the contents of GDB's internal line table data struture.
1249 Run any GDB unit tests that were compiled in.
1252 Start a new user interface instance running INTERP as interpreter,
1253 using the TTY file for input/output.
1257 ** gdb.Breakpoint objects have a new attribute "pending", which
1258 indicates whether the breakpoint is pending.
1259 ** Three new breakpoint-related events have been added:
1260 gdb.breakpoint_created, gdb.breakpoint_modified, and
1261 gdb.breakpoint_deleted.
1263 signal-event EVENTID
1264 Signal ("set") the given MS-Windows event object. This is used in
1265 conjunction with the Windows JIT debugging (AeDebug) support, where
1266 the OS suspends a crashing process until a debugger can attach to
1267 it. Resuming the crashing process, in order to debug it, is done by
1268 signalling an event.
1270 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1271 was added in GDBserver, including JIT compiling fast tracepoint's
1272 conditional expression bytecode into native code.
1274 * Support for various remote target protocols and ROM monitors has
1277 target m32rsdi Remote M32R debugging over SDI
1278 target mips MIPS remote debugging protocol
1279 target pmon PMON ROM monitor
1280 target ddb NEC's DDB variant of PMON for Vr4300
1281 target rockhopper NEC RockHopper variant of PMON
1282 target lsi LSI variant of PMO
1284 * Support for tracepoints and fast tracepoints on powerpc-linux,
1285 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1286 including JIT compiling fast tracepoint's conditional expression
1287 bytecode into native code.
1289 * MI async record =record-started now includes the method and format used for
1290 recording. For example:
1292 =record-started,thread-group="i1",method="btrace",format="bts"
1294 * MI async record =thread-selected now includes the frame field. For example:
1296 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1300 Andes NDS32 nds32*-*-elf
1302 *** Changes in GDB 7.11
1304 * GDB now supports debugging kernel-based threads on FreeBSD.
1306 * Per-inferior thread numbers
1308 Thread numbers are now per inferior instead of global. If you're
1309 debugging multiple inferiors, GDB displays thread IDs using a
1310 qualified INF_NUM.THR_NUM form. For example:
1314 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1315 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1316 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1317 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1319 As consequence, thread numbers as visible in the $_thread
1320 convenience variable and in Python's InferiorThread.num attribute
1321 are no longer unique between inferiors.
1323 GDB now maintains a second thread ID per thread, referred to as the
1324 global thread ID, which is the new equivalent of thread numbers in
1325 previous releases. See also $_gthread below.
1327 For backwards compatibility, MI's thread IDs always refer to global
1330 * Commands that accept thread IDs now accept the qualified
1331 INF_NUM.THR_NUM form as well. For example:
1334 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1337 * In commands that accept a list of thread IDs, you can now refer to
1338 all threads of an inferior using a star wildcard. GDB accepts
1339 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1340 refer to all threads of the current inferior. For example, "info
1343 * You can use "info threads -gid" to display the global thread ID of
1346 * The new convenience variable $_gthread holds the global number of
1349 * The new convenience variable $_inferior holds the number of the
1352 * GDB now displays the ID and name of the thread that hit a breakpoint
1353 or received a signal, if your program is multi-threaded. For
1356 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1357 Thread 1 "main" received signal SIGINT, Interrupt.
1359 * Record btrace now supports non-stop mode.
1361 * Support for tracepoints on aarch64-linux was added in GDBserver.
1363 * The 'record instruction-history' command now indicates speculative execution
1364 when using the Intel Processor Trace recording format.
1366 * GDB now allows users to specify explicit locations, bypassing
1367 the linespec parser. This feature is also available to GDB/MI
1370 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1371 GDB now is able to debug both AArch64 applications and ARM applications
1374 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1375 including JIT compiling fast tracepoint's conditional expression bytecode
1378 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1380 * "info threads", "info inferiors", "info display", "info checkpoints"
1381 and "maint info program-spaces" now list the corresponding items in
1382 ascending ID order, for consistency with all other "info" commands.
1384 * In Ada, the overloads selection menu has been enhanced to display the
1385 parameter types and the return types for the matching overloaded subprograms.
1389 maint set target-non-stop (on|off|auto)
1390 maint show target-non-stop
1391 Control whether GDB targets always operate in non-stop mode even if
1392 "set non-stop" is "off". The default is "auto", meaning non-stop
1393 mode is enabled if supported by the target.
1395 maint set bfd-sharing
1396 maint show bfd-sharing
1397 Control the reuse of bfd objects.
1400 show debug bfd-cache
1401 Control display of debugging info regarding bfd caching.
1405 Control display of debugging info regarding FreeBSD threads.
1407 set remote multiprocess-extensions-packet
1408 show remote multiprocess-extensions-packet
1409 Set/show the use of the remote protocol multiprocess extensions.
1411 set remote thread-events
1412 show remote thread-events
1413 Set/show the use of thread create/exit events.
1415 set ada print-signatures on|off
1416 show ada print-signatures"
1417 Control whether parameter types and return types are displayed in overloads
1418 selection menus. It is activaled (@code{on}) by default.
1422 Controls the maximum size of memory, in bytes, that GDB will
1423 allocate for value contents. Prevents incorrect programs from
1424 causing GDB to allocate overly large buffers. Default is 64k.
1426 * The "disassemble" command accepts a new modifier: /s.
1427 It prints mixed source+disassembly like /m with two differences:
1428 - disassembled instructions are now printed in program order, and
1429 - and source for all relevant files is now printed.
1430 The "/m" option is now considered deprecated: its "source-centric"
1431 output hasn't proved useful in practice.
1433 * The "record instruction-history" command accepts a new modifier: /s.
1434 It behaves exactly like /m and prints mixed source+disassembly.
1436 * The "set scheduler-locking" command supports a new mode "replay".
1437 It behaves like "off" in record mode and like "on" in replay mode.
1439 * Support for various ROM monitors has been removed:
1441 target dbug dBUG ROM monitor for Motorola ColdFire
1442 target picobug Motorola picobug monitor
1443 target dink32 DINK32 ROM monitor for PowerPC
1444 target m32r Renesas M32R/D ROM monitor
1445 target mon2000 mon2000 ROM monitor
1446 target ppcbug PPCBUG ROM monitor for PowerPC
1448 * Support for reading/writing memory and extracting values on architectures
1449 whose memory is addressable in units of any integral multiple of 8 bits.
1452 Allows to break when an Ada exception is handled.
1454 * New remote packets
1457 Indicates that an exec system call was executed.
1459 exec-events feature in qSupported
1460 The qSupported packet allows GDB to request support for exec
1461 events using the new 'gdbfeature' exec-event, and the qSupported
1462 response can contain the corresponding 'stubfeature'. Set and
1463 show commands can be used to display whether these features are enabled.
1466 Equivalent to interrupting with the ^C character, but works in
1469 thread created stop reason (T05 create:...)
1470 Indicates that the thread was just created and is stopped at entry.
1472 thread exit stop reply (w exitcode;tid)
1473 Indicates that the thread has terminated.
1476 Enables/disables thread create and exit event reporting. For
1477 example, this is used in non-stop mode when GDB stops a set of
1478 threads and synchronously waits for the their corresponding stop
1479 replies. Without exit events, if one of the threads exits, GDB
1480 would hang forever not knowing that it should no longer expect a
1481 stop for that same thread.
1484 Indicates that there are no resumed threads left in the target (all
1485 threads are stopped). The remote stub reports support for this stop
1486 reply to GDB's qSupported query.
1489 Enables/disables catching syscalls from the inferior process.
1490 The remote stub reports support for this packet to GDB's qSupported query.
1492 syscall_entry stop reason
1493 Indicates that a syscall was just called.
1495 syscall_return stop reason
1496 Indicates that a syscall just returned.
1498 * Extended-remote exec events
1500 ** GDB now has support for exec events on extended-remote Linux targets.
1501 For such targets with Linux kernels 2.5.46 and later, this enables
1502 follow-exec-mode and exec catchpoints.
1504 set remote exec-event-feature-packet
1505 show remote exec-event-feature-packet
1506 Set/show the use of the remote exec event feature.
1508 * Thread names in remote protocol
1510 The reply to qXfer:threads:read may now include a name attribute for each
1513 * Target remote mode fork and exec events
1515 ** GDB now has support for fork and exec events on target remote mode
1516 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1517 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1518 fork and exec catchpoints.
1520 * Remote syscall events
1522 ** GDB now has support for catch syscall on remote Linux targets,
1523 currently enabled on x86/x86_64 architectures.
1525 set remote catch-syscall-packet
1526 show remote catch-syscall-packet
1527 Set/show the use of the remote catch syscall feature.
1531 ** The -var-set-format command now accepts the zero-hexadecimal
1532 format. It outputs data in hexadecimal format with zero-padding on the
1537 ** gdb.InferiorThread objects have a new attribute "global_num",
1538 which refers to the thread's global thread ID. The existing
1539 "num" attribute now refers to the thread's per-inferior number.
1540 See "Per-inferior thread numbers" above.
1541 ** gdb.InferiorThread objects have a new attribute "inferior", which
1542 is the Inferior object the thread belongs to.
1544 *** Changes in GDB 7.10
1546 * Support for process record-replay and reverse debugging on aarch64*-linux*
1547 targets has been added. GDB now supports recording of A64 instruction set
1548 including advance SIMD instructions.
1550 * Support for Sun's version of the "stabs" debug file format has been removed.
1552 * GDB now honors the content of the file /proc/PID/coredump_filter
1553 (PID is the process ID) on GNU/Linux systems. This file can be used
1554 to specify the types of memory mappings that will be included in a
1555 corefile. For more information, please refer to the manual page of
1556 "core(5)". GDB also has a new command: "set use-coredump-filter
1557 on|off". It allows to set whether GDB will read the content of the
1558 /proc/PID/coredump_filter file when generating a corefile.
1560 * The "info os" command on GNU/Linux can now display information on
1562 "info os cpus" Listing of all cpus/cores on the system
1564 * GDB has two new commands: "set serial parity odd|even|none" and
1565 "show serial parity". These allows to set or show parity for the
1568 * The "info source" command now displays the producer string if it was
1569 present in the debug info. This typically includes the compiler version
1570 and may include things like its command line arguments.
1572 * The "info dll", an alias of the "info sharedlibrary" command,
1573 is now available on all platforms.
1575 * Directory names supplied to the "set sysroot" commands may be
1576 prefixed with "target:" to tell GDB to access shared libraries from
1577 the target system, be it local or remote. This replaces the prefix
1578 "remote:". The default sysroot has been changed from "" to
1579 "target:". "remote:" is automatically converted to "target:" for
1580 backward compatibility.
1582 * The system root specified by "set sysroot" will be prepended to the
1583 filename of the main executable (if reported to GDB as absolute by
1584 the operating system) when starting processes remotely, and when
1585 attaching to already-running local or remote processes.
1587 * GDB now supports automatic location and retrieval of executable
1588 files from remote targets. Remote debugging can now be initiated
1589 using only a "target remote" or "target extended-remote" command
1590 (no "set sysroot" or "file" commands are required). See "New remote
1593 * The "dump" command now supports verilog hex format.
1595 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1597 * On GNU/Linux, GDB and gdbserver are now able to access executable
1598 and shared library files without a "set sysroot" command when
1599 attaching to processes running in different mount namespaces from
1600 the debugger. This makes it possible to attach to processes in
1601 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1602 See "New remote packets" below.
1604 * The "tui reg" command now provides completion for all of the
1605 available register groups, including target specific groups.
1607 * The HISTSIZE environment variable is no longer read when determining
1608 the size of GDB's command history. GDB now instead reads the dedicated
1609 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1610 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1615 ** Memory ports can now be unbuffered.
1619 ** gdb.Objfile objects have a new attribute "username",
1620 which is the name of the objfile as specified by the user,
1621 without, for example, resolving symlinks.
1622 ** You can now write frame unwinders in Python.
1623 ** gdb.Type objects have a new method "optimized_out",
1624 returning optimized out gdb.Value instance of this type.
1625 ** gdb.Value objects have new methods "reference_value" and
1626 "const_value" which return a reference to the value and a
1627 "const" version of the value respectively.
1631 maint print symbol-cache
1632 Print the contents of the symbol cache.
1634 maint print symbol-cache-statistics
1635 Print statistics of symbol cache usage.
1637 maint flush-symbol-cache
1638 Flush the contents of the symbol cache.
1642 Start branch trace recording using Branch Trace Store (BTS) format.
1645 Evaluate expression by using the compiler and print result.
1649 Explicit commands for enabling and disabling tui mode.
1652 set mpx bound on i386 and amd64
1653 Support for bound table investigation on Intel MPX enabled applications.
1657 Start branch trace recording using Intel Processor Trace format.
1660 Print information about branch tracing internals.
1662 maint btrace packet-history
1663 Print the raw branch tracing data.
1665 maint btrace clear-packet-history
1666 Discard the stored raw branch tracing data.
1669 Discard all branch tracing data. It will be fetched and processed
1670 anew by the next "record" command.
1675 Renamed from "set debug dwarf2-die".
1676 show debug dwarf-die
1677 Renamed from "show debug dwarf2-die".
1679 set debug dwarf-read
1680 Renamed from "set debug dwarf2-read".
1681 show debug dwarf-read
1682 Renamed from "show debug dwarf2-read".
1684 maint set dwarf always-disassemble
1685 Renamed from "maint set dwarf2 always-disassemble".
1686 maint show dwarf always-disassemble
1687 Renamed from "maint show dwarf2 always-disassemble".
1689 maint set dwarf max-cache-age
1690 Renamed from "maint set dwarf2 max-cache-age".
1691 maint show dwarf max-cache-age
1692 Renamed from "maint show dwarf2 max-cache-age".
1694 set debug dwarf-line
1695 show debug dwarf-line
1696 Control display of debugging info regarding DWARF line processing.
1699 show max-completions
1700 Set the maximum number of candidates to be considered during
1701 completion. The default value is 200. This limit allows GDB
1702 to avoid generating large completion lists, the computation of
1703 which can cause the debugger to become temporarily unresponsive.
1705 set history remove-duplicates
1706 show history remove-duplicates
1707 Control the removal of duplicate history entries.
1709 maint set symbol-cache-size
1710 maint show symbol-cache-size
1711 Control the size of the symbol cache.
1713 set|show record btrace bts buffer-size
1714 Set and show the size of the ring buffer used for branch tracing in
1716 The obtained size may differ from the requested size. Use "info
1717 record" to see the obtained buffer size.
1719 set debug linux-namespaces
1720 show debug linux-namespaces
1721 Control display of debugging info regarding Linux namespaces.
1723 set|show record btrace pt buffer-size
1724 Set and show the size of the ring buffer used for branch tracing in
1725 Intel Processor Trace format.
1726 The obtained size may differ from the requested size. Use "info
1727 record" to see the obtained buffer size.
1729 maint set|show btrace pt skip-pad
1730 Set and show whether PAD packets are skipped when computing the
1733 * The command 'thread apply all' can now support new option '-ascending'
1734 to call its specified command for all threads in ascending order.
1736 * Python/Guile scripting
1738 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1739 special section named `.debug_gdb_scripts'.
1741 * New remote packets
1743 qXfer:btrace-conf:read
1744 Return the branch trace configuration for the current thread.
1746 Qbtrace-conf:bts:size
1747 Set the requested ring buffer size for branch tracing in BTS format.
1750 Enable Intel Procesor Trace-based branch tracing for the current
1751 process. The remote stub reports support for this packet to GDB's
1754 Qbtrace-conf:pt:size
1755 Set the requested ring buffer size for branch tracing in Intel Processor
1759 Indicates a memory breakpoint instruction was executed, irrespective
1760 of whether it was GDB that planted the breakpoint or the breakpoint
1761 is hardcoded in the program. This is required for correct non-stop
1765 Indicates the target stopped for a hardware breakpoint. This is
1766 required for correct non-stop mode operation.
1769 Return information about files on the remote system.
1771 qXfer:exec-file:read
1772 Return the full absolute name of the file that was executed to
1773 create a process running on the remote system.
1776 Select the filesystem on which vFile: operations with filename
1777 arguments will operate. This is required for GDB to be able to
1778 access files on remote targets where the remote stub does not
1779 share a common filesystem with the inferior(s).
1782 Indicates that a fork system call was executed.
1785 Indicates that a vfork system call was executed.
1787 vforkdone stop reason
1788 Indicates that a vfork child of the specified process has executed
1789 an exec or exit, allowing the vfork parent to resume execution.
1791 fork-events and vfork-events features in qSupported
1792 The qSupported packet allows GDB to request support for fork and
1793 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1794 and the qSupported response can contain the corresponding
1795 'stubfeatures'. Set and show commands can be used to display
1796 whether these features are enabled.
1798 * Extended-remote fork events
1800 ** GDB now has support for fork events on extended-remote Linux
1801 targets. For targets with Linux kernels 2.5.60 and later, this
1802 enables follow-fork-mode and detach-on-fork for both fork and
1803 vfork, as well as fork and vfork catchpoints.
1805 * The info record command now shows the recording format and the
1806 branch tracing configuration for the current thread when using
1807 the btrace record target.
1808 For the BTS format, it shows the ring buffer size.
1810 * GDB now has support for DTrace USDT (Userland Static Defined
1811 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1813 * GDB now supports access to vector registers on S/390 GNU/Linux
1816 * Removed command line options
1818 -xdb HP-UX XDB compatibility mode.
1820 * Removed targets and native configurations
1822 HP/PA running HP-UX hppa*-*-hpux*
1823 Itanium running HP-UX ia64-*-hpux*
1825 * New configure options
1828 This configure option allows the user to build GDB with support for
1829 Intel Processor Trace (default: auto). This requires libipt.
1831 --with-libipt-prefix=PATH
1832 Specify the path to the version of libipt that GDB should use.
1833 $PATH/include should contain the intel-pt.h header and
1834 $PATH/lib should contain the libipt.so library.
1836 *** Changes in GDB 7.9.1
1840 ** Xmethods can now specify a result type.
1842 *** Changes in GDB 7.9
1844 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1848 ** You can now access frame registers from Python scripts.
1849 ** New attribute 'producer' for gdb.Symtab objects.
1850 ** gdb.Objfile objects have a new attribute "progspace",
1851 which is the gdb.Progspace object of the containing program space.
1852 ** gdb.Objfile objects have a new attribute "owner".
1853 ** gdb.Objfile objects have a new attribute "build_id",
1854 which is the build ID generated when the file was built.
1855 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1856 ** A new event "gdb.clear_objfiles" has been added, triggered when
1857 selecting a new file to debug.
1858 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1859 ** New function gdb.lookup_objfile.
1861 New events which are triggered when GDB modifies the state of the
1864 ** gdb.events.inferior_call_pre: Function call is about to be made.
1865 ** gdb.events.inferior_call_post: Function call has just been made.
1866 ** gdb.events.memory_changed: A memory location has been altered.
1867 ** gdb.events.register_changed: A register has been altered.
1869 * New Python-based convenience functions:
1871 ** $_caller_is(name [, number_of_frames])
1872 ** $_caller_matches(regexp [, number_of_frames])
1873 ** $_any_caller_is(name [, number_of_frames])
1874 ** $_any_caller_matches(regexp [, number_of_frames])
1876 * GDB now supports the compilation and injection of source code into
1877 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1878 to compile the source code to object code, and if successful, inject
1879 and execute that code within the current context of the inferior.
1880 Currently the C language is supported. The commands used to
1881 interface with this new feature are:
1883 compile code [-raw|-r] [--] [source code]
1884 compile file [-raw|-r] filename
1888 demangle [-l language] [--] name
1889 Demangle "name" in the specified language, or the current language
1890 if elided. This command is renamed from the "maint demangle" command.
1891 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1892 as "maint demangler-warning".
1894 queue-signal signal-name-or-number
1895 Queue a signal to be delivered to the thread when it is resumed.
1897 add-auto-load-scripts-directory directory
1898 Add entries to the list of directories from which to load auto-loaded
1901 maint print user-registers
1902 List all currently available "user" registers.
1904 compile code [-r|-raw] [--] [source code]
1905 Compile, inject, and execute in the inferior the executable object
1906 code produced by compiling the provided source code.
1908 compile file [-r|-raw] filename
1909 Compile and inject into the inferior the executable object code
1910 produced by compiling the source code stored in the filename
1913 * On resume, GDB now always passes the signal the program had stopped
1914 for to the thread the signal was sent to, even if the user changed
1915 threads before resuming. Previously GDB would often (but not
1916 always) deliver the signal to the thread that happens to be current
1919 * Conversely, the "signal" command now consistently delivers the
1920 requested signal to the current thread. GDB now asks for
1921 confirmation if the program had stopped for a signal and the user
1922 switched threads meanwhile.
1924 * "breakpoint always-inserted" modes "off" and "auto" merged.
1926 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1927 won't remove breakpoints from the target until all threads stop,
1928 even in non-stop mode. The "auto" mode has been removed, and "off"
1929 is now the default mode.
1933 set debug symbol-lookup
1934 show debug symbol-lookup
1935 Control display of debugging info regarding symbol lookup.
1939 ** The -list-thread-groups command outputs an exit-code field for
1940 inferiors that have exited.
1944 MIPS SDE mips*-sde*-elf*
1948 Support for these obsolete configurations has been removed.
1950 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1951 SGI Irix-5.x mips-*-irix5*
1952 SGI Irix-6.x mips-*-irix6*
1953 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1954 VAX running Ultrix vax-*-ultrix*
1956 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1957 and "assf"), have been removed. Use the "sharedlibrary" command, or
1958 its alias "share", instead.
1960 *** Changes in GDB 7.8
1962 * New command line options
1965 This is an alias for the --data-directory option.
1967 * GDB supports printing and modifying of variable length automatic arrays
1968 as specified in ISO C99.
1970 * The ARM simulator now supports instruction level tracing
1971 with or without disassembly.
1975 GDB now has support for scripting using Guile. Whether this is
1976 available is determined at configure time.
1977 Guile version 2.0 or greater is required.
1978 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1980 * New commands (for set/show, see "New options" below)
1984 Invoke CODE by passing it to the Guile interpreter.
1988 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1990 info auto-load guile-scripts [regexp]
1991 Print the list of automatically loaded Guile scripts.
1993 * The source command is now capable of sourcing Guile scripts.
1994 This feature is dependent on the debugger being built with Guile support.
1998 set print symbol-loading (off|brief|full)
1999 show print symbol-loading
2000 Control whether to print informational messages when loading symbol
2001 information for a file. The default is "full", but when debugging
2002 programs with large numbers of shared libraries the amount of output
2003 becomes less useful.
2005 set guile print-stack (none|message|full)
2006 show guile print-stack
2007 Show a stack trace when an error is encountered in a Guile script.
2009 set auto-load guile-scripts (on|off)
2010 show auto-load guile-scripts
2011 Control auto-loading of Guile script files.
2013 maint ada set ignore-descriptive-types (on|off)
2014 maint ada show ignore-descriptive-types
2015 Control whether the debugger should ignore descriptive types in Ada
2016 programs. The default is not to ignore the descriptive types. See
2017 the user manual for more details on descriptive types and the intended
2018 usage of this option.
2020 set auto-connect-native-target
2022 Control whether GDB is allowed to automatically connect to the
2023 native target for the run, attach, etc. commands when not connected
2024 to any target yet. See also "target native" below.
2026 set record btrace replay-memory-access (read-only|read-write)
2027 show record btrace replay-memory-access
2028 Control what memory accesses are allowed during replay.
2030 maint set target-async (on|off)
2031 maint show target-async
2032 This controls whether GDB targets operate in synchronous or
2033 asynchronous mode. Normally the default is asynchronous, if it is
2034 available; but this can be changed to more easily debug problems
2035 occurring only in synchronous mode.
2037 set mi-async (on|off)
2039 Control whether MI asynchronous mode is preferred. This supersedes
2040 "set target-async" of previous GDB versions.
2042 * "set target-async" is deprecated as a CLI option and is now an alias
2043 for "set mi-async" (only puts MI into async mode).
2045 * Background execution commands (e.g., "c&", "s&", etc.) are now
2046 possible ``out of the box'' if the target supports them. Previously
2047 the user would need to explicitly enable the possibility with the
2048 "set target-async on" command.
2050 * New features in the GDB remote stub, GDBserver
2052 ** New option --debug-format=option1[,option2,...] allows one to add
2053 additional text to each output. At present only timestamps
2054 are supported: --debug-format=timestamps.
2055 Timestamps can also be turned on with the
2056 "monitor set debug-format timestamps" command from GDB.
2058 * The 'record instruction-history' command now starts counting instructions
2059 at one. This also affects the instruction ranges reported by the
2060 'record function-call-history' command when given the /i modifier.
2062 * The command 'record function-call-history' supports a new modifier '/c' to
2063 indent the function names based on their call stack depth.
2064 The fields for the '/i' and '/l' modifier have been reordered.
2065 The source line range is now prefixed with 'at'.
2066 The instruction range is now prefixed with 'inst'.
2067 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2068 "record instruction-history" and "list" commands.
2070 * The ranges given as arguments to the 'record function-call-history' and
2071 'record instruction-history' commands are now inclusive.
2073 * The btrace record target now supports the 'record goto' command.
2074 For locations inside the execution trace, the back trace is computed
2075 based on the information stored in the execution trace.
2077 * The btrace record target supports limited reverse execution and replay.
2078 The target does not record data and therefore does not allow reading
2079 memory or registers.
2081 * The "catch syscall" command now works on s390*-linux* targets.
2083 * The "compare-sections" command is no longer specific to target
2084 remote. It now works with all targets.
2086 * All native targets are now consistently called "native".
2087 Consequently, the "target child", "target GNU", "target djgpp",
2088 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2089 commands have been replaced with "target native". The QNX/NTO port
2090 leaves the "procfs" target in place and adds a "native" target for
2091 consistency with other ports. The impact on users should be minimal
2092 as these commands previously either throwed an error, or were
2093 no-ops. The target's name is visible in the output of the following
2094 commands: "help target", "info target", "info files", "maint print
2097 * The "target native" command now connects to the native target. This
2098 can be used to launch native programs even when "set
2099 auto-connect-native-target" is set to off.
2101 * GDB now supports access to Intel MPX registers on GNU/Linux.
2103 * Support for Intel AVX-512 registers on GNU/Linux.
2104 Support displaying and modifying Intel AVX-512 registers
2105 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2107 * New remote packets
2109 qXfer:btrace:read's annex
2110 The qXfer:btrace:read packet supports a new annex 'delta' to read
2111 branch trace incrementally.
2115 ** Valid Python operations on gdb.Value objects representing
2116 structs/classes invoke the corresponding overloaded operators if
2118 ** New `Xmethods' feature in the Python API. Xmethods are
2119 additional methods or replacements for existing methods of a C++
2120 class. This feature is useful for those cases where a method
2121 defined in C++ source code could be inlined or optimized out by
2122 the compiler, making it unavailable to GDB.
2125 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2127 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2128 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2129 its alias "share", instead.
2131 * The commands "set remotebaud" and "show remotebaud" are no longer
2132 supported. Use "set serial baud" and "show serial baud" (respectively)
2137 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2138 target-async". The latter is left as a deprecated alias of the
2139 former for backward compatibility. If the target supports it,
2140 CLI background execution commands are now always possible by
2141 default, independently of whether the frontend stated a
2142 preference for asynchronous execution with "-gdb-set mi-async".
2143 Previously "-gdb-set target-async off" affected both MI execution
2144 commands and CLI execution commands.
2146 *** Changes in GDB 7.7
2148 * Improved support for process record-replay and reverse debugging on
2149 arm*-linux* targets. Support for thumb32 and syscall instruction
2150 recording has been added.
2152 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2154 * GDB now supports Fission DWP file format version 2.
2155 http://gcc.gnu.org/wiki/DebugFission
2157 * New convenience function "$_isvoid", to check whether an expression
2158 is void. A void expression is an expression where the type of the
2159 result is "void". For example, some convenience variables may be
2160 "void" when evaluated (e.g., "$_exitcode" before the execution of
2161 the program being debugged; or an undefined convenience variable).
2162 Another example, when calling a function whose return type is
2165 * The "maintenance print objfiles" command now takes an optional regexp.
2167 * The "catch syscall" command now works on arm*-linux* targets.
2169 * GDB now consistently shows "<not saved>" when printing values of
2170 registers the debug info indicates have not been saved in the frame
2171 and there's nowhere to retrieve them from
2172 (callee-saved/call-clobbered registers):
2177 (gdb) info registers rax
2180 Before, the former would print "<optimized out>", and the latter
2181 "*value not available*".
2183 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2188 ** Frame filters and frame decorators have been added.
2189 ** Temporary breakpoints are now supported.
2190 ** Line tables representation has been added.
2191 ** New attribute 'parent_type' for gdb.Field objects.
2192 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2193 ** New attribute 'name' for gdb.Type objects.
2197 Nios II ELF nios2*-*-elf
2198 Nios II GNU/Linux nios2*-*-linux
2199 Texas Instruments MSP430 msp430*-*-elf
2201 * Removed native configurations
2203 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2204 been removed. ELF variants of these configurations are kept supported.
2206 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2207 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2208 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2209 i[34567]86-*-openbsd3.[0-3]
2210 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2211 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2212 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2216 Like "catch throw", but catches a re-thrown exception.
2217 maint check-psymtabs
2218 Renamed from old "maint check-symtabs".
2220 Perform consistency checks on symtabs.
2221 maint expand-symtabs
2222 Expand symtabs matching an optional regexp.
2225 Display the details of GDB configure-time options.
2227 maint set|show per-command
2228 maint set|show per-command space
2229 maint set|show per-command time
2230 maint set|show per-command symtab
2231 Enable display of per-command gdb resource usage.
2233 remove-symbol-file FILENAME
2234 remove-symbol-file -a ADDRESS
2235 Remove a symbol file added via add-symbol-file. The file to remove
2236 can be identified by its filename or by an address that lies within
2237 the boundaries of this symbol file in memory.
2240 info exceptions REGEXP
2241 Display the list of Ada exceptions defined in the program being
2242 debugged. If provided, only the exceptions whose names match REGEXP
2247 set debug symfile off|on
2249 Control display of debugging info regarding reading symbol files and
2250 symbol tables within those files
2252 set print raw frame-arguments
2253 show print raw frame-arguments
2254 Set/show whether to print frame arguments in raw mode,
2255 disregarding any defined pretty-printers.
2257 set remote trace-status-packet
2258 show remote trace-status-packet
2259 Set/show the use of remote protocol qTStatus packet.
2263 Control display of debugging messages related to Nios II targets.
2267 Control whether target-assisted range stepping is enabled.
2269 set startup-with-shell
2270 show startup-with-shell
2271 Specifies whether Unix child processes are started via a shell or
2276 Use the target memory cache for accesses to the code segment. This
2277 improves performance of remote debugging (particularly disassembly).
2279 * You can now use a literal value 'unlimited' for options that
2280 interpret 0 or -1 as meaning "unlimited". E.g., "set
2281 trace-buffer-size unlimited" is now an alias for "set
2282 trace-buffer-size -1" and "set height unlimited" is now an alias for
2285 * The "set debug symtab-create" debugging option of GDB has been changed to
2286 accept a verbosity level. 0 means "off", 1 provides basic debugging
2287 output, and values of 2 or greater provides more verbose output.
2289 * New command-line options
2291 Display the details of GDB configure-time options.
2293 * The command 'tsave' can now support new option '-ctf' to save trace
2294 buffer in Common Trace Format.
2296 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2299 * GDB now implements the the C++ 'typeid' operator.
2301 * The new convenience variable $_exception holds the exception being
2302 thrown or caught at an exception-related catchpoint.
2304 * The exception-related catchpoints, like "catch throw", now accept a
2305 regular expression which can be used to filter exceptions by type.
2307 * The new convenience variable $_exitsignal is automatically set to
2308 the terminating signal number when the program being debugged dies
2309 due to an uncaught signal.
2313 ** All MI commands now accept an optional "--language" option.
2314 Support for this feature can be verified by using the "-list-features"
2315 command, which should contain "language-option".
2317 ** The new command -info-gdb-mi-command allows the user to determine
2318 whether a GDB/MI command is supported or not.
2320 ** The "^error" result record returned when trying to execute an undefined
2321 GDB/MI command now provides a variable named "code" whose content is the
2322 "undefined-command" error code. Support for this feature can be verified
2323 by using the "-list-features" command, which should contain
2324 "undefined-command-error-code".
2326 ** The -trace-save MI command can optionally save trace buffer in Common
2329 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2331 ** The command -data-list-register-values now accepts an optional
2332 "--skip-unavailable" option. When used, only the available registers
2335 ** The new command -trace-frame-collected dumps collected variables,
2336 computed expressions, tvars, memory and registers in a traceframe.
2338 ** The commands -stack-list-locals, -stack-list-arguments and
2339 -stack-list-variables now accept an option "--skip-unavailable".
2340 When used, only the available locals or arguments are displayed.
2342 ** The -exec-run command now accepts an optional "--start" option.
2343 When used, the command follows the same semantics as the "start"
2344 command, stopping the program's execution at the start of its
2345 main subprogram. Support for this feature can be verified using
2346 the "-list-features" command, which should contain
2347 "exec-run-start-option".
2349 ** The new commands -catch-assert and -catch-exceptions insert
2350 catchpoints stopping the program when Ada exceptions are raised.
2352 ** The new command -info-ada-exceptions provides the equivalent of
2353 the new "info exceptions" command.
2355 * New system-wide configuration scripts
2356 A GDB installation now provides scripts suitable for use as system-wide
2357 configuration scripts for the following systems:
2361 * GDB now supports target-assigned range stepping with remote targets.
2362 This improves the performance of stepping source lines by reducing
2363 the number of control packets from/to GDB. See "New remote packets"
2366 * GDB now understands the element 'tvar' in the XML traceframe info.
2367 It has the id of the collected trace state variables.
2369 * On S/390 targets that provide the transactional-execution feature,
2370 the program interruption transaction diagnostic block (TDB) is now
2371 represented as a number of additional "registers" in GDB.
2373 * New remote packets
2377 The vCont packet supports a new 'r' action, that tells the remote
2378 stub to step through an address range itself, without GDB
2379 involvemement at each single-step.
2381 qXfer:libraries-svr4:read's annex
2382 The previously unused annex of the qXfer:libraries-svr4:read packet
2383 is now used to support passing an argument list. The remote stub
2384 reports support for this argument list to GDB's qSupported query.
2385 The defined arguments are "start" and "prev", used to reduce work
2386 necessary for library list updating, resulting in significant
2389 * New features in the GDB remote stub, GDBserver
2391 ** GDBserver now supports target-assisted range stepping. Currently
2392 enabled on x86/x86_64 GNU/Linux targets.
2394 ** GDBserver now adds element 'tvar' in the XML in the reply to
2395 'qXfer:traceframe-info:read'. It has the id of the collected
2396 trace state variables.
2398 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2401 * New 'z' formatter for printing and examining memory, this displays the
2402 value as hexadecimal zero padded on the left to the size of the type.
2404 * GDB can now use Windows x64 unwinding data.
2406 * The "set remotebaud" command has been replaced by "set serial baud".
2407 Similarly, "show remotebaud" has been replaced by "show serial baud".
2408 The "set remotebaud" and "show remotebaud" commands are still available
2409 to provide backward compatibility with older versions of GDB.
2411 *** Changes in GDB 7.6
2413 * Target record has been renamed to record-full.
2414 Record/replay is now enabled with the "record full" command.
2415 This also affects settings that are associated with full record/replay
2416 that have been moved from "set/show record" to "set/show record full":
2418 set|show record full insn-number-max
2419 set|show record full stop-at-limit
2420 set|show record full memory-query
2422 * A new record target "record-btrace" has been added. The new target
2423 uses hardware support to record the control-flow of a process. It
2424 does not support replaying the execution, but it implements the
2425 below new commands for investigating the recorded execution log.
2426 This new recording method can be enabled using:
2430 The "record-btrace" target is only available on Intel Atom processors
2431 and requires a Linux kernel 2.6.32 or later.
2433 * Two new commands have been added for record/replay to give information
2434 about the recorded execution without having to replay the execution.
2435 The commands are only supported by "record btrace".
2437 record instruction-history prints the execution history at
2438 instruction granularity
2440 record function-call-history prints the execution history at
2441 function granularity
2443 * New native configurations
2445 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2446 FreeBSD/powerpc powerpc*-*-freebsd
2447 x86_64/Cygwin x86_64-*-cygwin*
2448 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2452 ARM AArch64 aarch64*-*-elf
2453 ARM AArch64 GNU/Linux aarch64*-*-linux
2454 Lynx 178 PowerPC powerpc-*-lynx*178
2455 x86_64/Cygwin x86_64-*-cygwin*
2456 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2458 * If the configured location of system.gdbinit file (as given by the
2459 --with-system-gdbinit option at configure time) is in the
2460 data-directory (as specified by --with-gdb-datadir at configure
2461 time) or in one of its subdirectories, then GDB will look for the
2462 system-wide init file in the directory specified by the
2463 --data-directory command-line option.
2465 * New command line options:
2467 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2468 other initialization files, unlike -nx which disables all of them.
2470 * Removed command line options
2472 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2475 * The 'ptype' and 'whatis' commands now accept an argument to control
2478 * 'info proc' now works on some core files.
2482 ** Vectors can be created with gdb.Type.vector.
2484 ** Python's atexit.register now works in GDB.
2486 ** Types can be pretty-printed via a Python API.
2488 ** Python 3 is now supported (in addition to Python 2.4 or later)
2490 ** New class gdb.Architecture exposes GDB's internal representation
2491 of architecture in the Python API.
2493 ** New method Frame.architecture returns the gdb.Architecture object
2494 corresponding to the frame's architecture.
2496 * New Python-based convenience functions:
2498 ** $_memeq(buf1, buf2, length)
2499 ** $_streq(str1, str2)
2501 ** $_regex(str, regex)
2503 * The 'cd' command now defaults to using '~' (the home directory) if not
2506 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2507 default for GCC since November 2000.
2509 * The command 'forward-search' can now be abbreviated as 'fo'.
2511 * The command 'info tracepoints' can now display 'installed on target'
2512 or 'not installed on target' for each non-pending location of tracepoint.
2514 * New configure options
2516 --enable-libmcheck/--disable-libmcheck
2517 By default, development versions are built with -lmcheck on hosts
2518 that support it, in order to help track memory corruption issues.
2519 Release versions, on the other hand, are built without -lmcheck
2520 by default. The --enable-libmcheck/--disable-libmcheck configure
2521 options allow the user to override that default.
2522 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2523 This configure option allows the user to build GDB with
2524 libbabeltrace using which GDB can read Common Trace Format data.
2526 * New commands (for set/show, see "New options" below)
2529 Catch signals. This is similar to "handle", but allows commands and
2530 conditions to be attached.
2533 List the BFDs known to GDB.
2535 python-interactive [command]
2537 Start a Python interactive prompt, or evaluate the optional command
2538 and print the result of expressions.
2541 "py" is a new alias for "python".
2543 enable type-printer [name]...
2544 disable type-printer [name]...
2545 Enable or disable type printers.
2549 ** For the Renesas Super-H architecture, the "regs" command has been removed
2550 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2555 set print type methods (on|off)
2556 show print type methods
2557 Control whether method declarations are displayed by "ptype".
2558 The default is to show them.
2560 set print type typedefs (on|off)
2561 show print type typedefs
2562 Control whether typedef definitions are displayed by "ptype".
2563 The default is to show them.
2565 set filename-display basename|relative|absolute
2566 show filename-display
2567 Control the way in which filenames is displayed.
2568 The default is "relative", which preserves previous behavior.
2570 set trace-buffer-size
2571 show trace-buffer-size
2572 Request target to change the size of trace buffer.
2574 set remote trace-buffer-size-packet auto|on|off
2575 show remote trace-buffer-size-packet
2576 Control the use of the remote protocol `QTBuffer:size' packet.
2580 Control display of debugging messages related to ARM AArch64.
2583 set debug coff-pe-read
2584 show debug coff-pe-read
2585 Control display of debugging messages related to reading of COFF/PE
2590 Control display of debugging messages related to Mach-O symbols
2593 set debug notification
2594 show debug notification
2595 Control display of debugging info for async remote notification.
2599 ** Command parameter changes are now notified using new async record
2600 "=cmd-param-changed".
2601 ** Trace frame changes caused by command "tfind" are now notified using
2602 new async record "=traceframe-changed".
2603 ** The creation, deletion and modification of trace state variables
2604 are now notified using new async records "=tsv-created",
2605 "=tsv-deleted" and "=tsv-modified".
2606 ** The start and stop of process record are now notified using new
2607 async record "=record-started" and "=record-stopped".
2608 ** Memory changes are now notified using new async record
2610 ** The data-disassemble command response will include a "fullname" field
2611 containing the absolute file name when source has been requested.
2612 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2613 command, to allow pattern filling of memory areas.
2614 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2615 library load/unload events.
2616 ** The response to breakpoint commands and breakpoint async records
2617 includes an "installed" field containing a boolean state about each
2618 non-pending tracepoint location is whether installed on target or not.
2619 ** Output of the "-trace-status" command includes a "trace-file" field
2620 containing the name of the trace file being examined. This field is
2621 optional, and only present when examining a trace file.
2622 ** The "fullname" field is now always present along with the "file" field,
2623 even if the file cannot be found by GDB.
2625 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2626 You must have the LZMA library available when configuring GDB for this
2627 feature to be enabled. For more information, see:
2628 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2630 * New remote packets
2633 Set the size of trace buffer. The remote stub reports support for this
2634 packet to gdb's qSupported query.
2637 Enable Branch Trace Store (BTS)-based branch tracing for the current
2638 thread. The remote stub reports support for this packet to gdb's
2642 Disable branch tracing for the current thread. The remote stub reports
2643 support for this packet to gdb's qSupported query.
2646 Read the traced branches for the current thread. The remote stub
2647 reports support for this packet to gdb's qSupported query.
2649 *** Changes in GDB 7.5
2651 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2652 for more x32 ABI info.
2654 * GDB now supports access to MIPS DSP registers on Linux targets.
2656 * GDB now supports debugging microMIPS binaries.
2658 * The "info os" command on GNU/Linux can now display information on
2659 several new classes of objects managed by the operating system:
2660 "info os procgroups" lists process groups
2661 "info os files" lists file descriptors
2662 "info os sockets" lists internet-domain sockets
2663 "info os shm" lists shared-memory regions
2664 "info os semaphores" lists semaphores
2665 "info os msg" lists message queues
2666 "info os modules" lists loaded kernel modules
2668 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2669 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2670 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2671 options and inspect the probe arguments using the new $_probe_arg family
2672 of convenience variables. You can obtain more information about SystemTap
2673 in <http://sourceware.org/systemtap/>.
2675 * GDB now supports reversible debugging on ARM, it allows you to
2676 debug basic ARM and THUMB instructions, and provides
2677 record/replay support.
2679 * The option "symbol-reloading" has been deleted as it is no longer used.
2683 ** GDB commands implemented in Python can now be put in command class
2686 ** The "maint set python print-stack on|off" is now deleted.
2688 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2689 apply "flag enum"-style pretty-printing to any enum.
2691 ** gdb.lookup_symbol can now work when there is no current frame.
2693 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2694 the source at which the symbol was defined.
2696 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2697 method 'value'. The former indicates whether the symbol needs a
2698 frame in order to compute its value, and the latter computes the
2701 ** A new method 'referenced_value' on gdb.Value objects which can
2702 dereference pointer as well as C++ reference values.
2704 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2705 which return the global and static blocks (as gdb.Block objects),
2706 of the underlying symbol table, respectively.
2708 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2709 object associated with a PC value.
2711 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2712 of the address range occupied by code for the current source line.
2714 * Go language support.
2715 GDB now supports debugging programs written in the Go programming
2718 * GDBserver now supports stdio connections.
2719 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2721 * The binary "gdbtui" can no longer be built or installed.
2722 Use "gdb -tui" instead.
2724 * GDB will now print "flag" enums specially. A flag enum is one where
2725 all the enumerator values have no bits in common when pairwise
2726 "and"ed. When printing a value whose type is a flag enum, GDB will
2727 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2728 (gdb) print (enum E) 3
2731 * The filename part of a linespec will now match trailing components
2732 of a source file name. For example, "break gcc/expr.c:1000" will
2733 now set a breakpoint in build/gcc/expr.c, but not
2734 build/libcpp/expr.c.
2736 * The "info proc" and "generate-core-file" commands will now also
2737 work on remote targets connected to GDBserver on Linux.
2739 * The command "info catch" has been removed. It has been disabled
2740 since December 2007.
2742 * The "catch exception" and "catch assert" commands now accept
2743 a condition at the end of the command, much like the "break"
2744 command does. For instance:
2746 (gdb) catch exception Constraint_Error if Barrier = True
2748 Previously, it was possible to add a condition to such catchpoints,
2749 but it had to be done as a second step, after the catchpoint had been
2750 created, using the "condition" command.
2752 * The "info static-tracepoint-marker" command will now also work on
2753 native Linux targets with in-process agent.
2755 * GDB can now set breakpoints on inlined functions.
2757 * The .gdb_index section has been updated to include symbols for
2758 inlined functions. GDB will ignore older .gdb_index sections by
2759 default, which could cause symbol files to be loaded more slowly
2760 until their .gdb_index sections can be recreated. The new command
2761 "set use-deprecated-index-sections on" will cause GDB to use any older
2762 .gdb_index sections it finds. This will restore performance, but the
2763 ability to set breakpoints on inlined functions will be lost in symbol
2764 files with older .gdb_index sections.
2766 The .gdb_index section has also been updated to record more information
2767 about each symbol. This speeds up the "info variables", "info functions"
2768 and "info types" commands when used with programs having the .gdb_index
2769 section, as well as speeding up debugging with shared libraries using
2770 the .gdb_index section.
2772 * Ada support for GDB/MI Variable Objects has been added.
2774 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2779 ** New command -info-os is the MI equivalent of "info os".
2781 ** Output logs ("set logging" and related) now include MI output.
2785 ** "set use-deprecated-index-sections on|off"
2786 "show use-deprecated-index-sections on|off"
2787 Controls the use of deprecated .gdb_index sections.
2789 ** "catch load" and "catch unload" can be used to stop when a shared
2790 library is loaded or unloaded, respectively.
2792 ** "enable count" can be used to auto-disable a breakpoint after
2795 ** "info vtbl" can be used to show the virtual method tables for
2796 C++ and Java objects.
2798 ** "explore" and its sub commands "explore value" and "explore type"
2799 can be used to recursively explore values and types of
2800 expressions. These commands are available only if GDB is
2801 configured with '--with-python'.
2803 ** "info auto-load" shows status of all kinds of auto-loaded files,
2804 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2805 sequences of commands files, "info auto-load python-scripts"
2806 shows status of auto-loading Python script files,
2807 "info auto-load local-gdbinit" shows status of loading init file
2808 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2809 status of inferior specific thread debugging shared library loading.
2811 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2812 and "show auto-load-scripts" commands have been deprecated, use their
2813 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2814 and "show auto-load python-scripts" counterparts instead.
2816 ** "dprintf location,format,args..." creates a dynamic printf, which
2817 is basically a breakpoint that does a printf and immediately
2818 resumes your program's execution, so it is like a printf that you
2819 can insert dynamically at runtime instead of at compiletime.
2821 ** "set print symbol"
2823 Controls whether GDB attempts to display the symbol, if any,
2824 corresponding to addresses it prints. This defaults to "on", but
2825 you can set it to "off" to restore GDB's previous behavior.
2827 * Deprecated commands
2829 ** For the Renesas Super-H architecture, the "regs" command has been
2830 deprecated, and "info all-registers" should be used instead.
2834 Renesas RL78 rl78-*-elf
2835 HP OpenVMS ia64 ia64-hp-openvms*
2837 * GDBserver supports evaluation of breakpoint conditions. When
2838 support is advertised by GDBserver, GDB may be told to send the
2839 breakpoint conditions in bytecode form to GDBserver. GDBserver
2840 will only report the breakpoint trigger to GDB when its condition
2845 set mips compression
2846 show mips compression
2847 Select the compressed ISA encoding used in functions that have no symbol
2848 information available. The encoding can be set to either of:
2851 and is updated automatically from ELF file flags if available.
2853 set breakpoint condition-evaluation
2854 show breakpoint condition-evaluation
2855 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2856 GDBserver ("target"). Default option "auto" chooses the most efficient
2858 This option can improve debugger efficiency depending on the speed of the
2862 Disable auto-loading globally.
2865 Show auto-loading setting of all kinds of auto-loaded files.
2867 set auto-load gdb-scripts on|off
2868 show auto-load gdb-scripts
2869 Control auto-loading of GDB canned sequences of commands files.
2871 set auto-load python-scripts on|off
2872 show auto-load python-scripts
2873 Control auto-loading of Python script files.
2875 set auto-load local-gdbinit on|off
2876 show auto-load local-gdbinit
2877 Control loading of init file (.gdbinit) from current directory.
2879 set auto-load libthread-db on|off
2880 show auto-load libthread-db
2881 Control auto-loading of inferior specific thread debugging shared library.
2883 set auto-load scripts-directory <dir1>[:<dir2>...]
2884 show auto-load scripts-directory
2885 Set a list of directories from which to load auto-loaded scripts.
2886 Automatically loaded Python scripts and GDB scripts are located in one
2887 of the directories listed by this option.
2888 The delimiter (':' above) may differ according to the host platform.
2890 set auto-load safe-path <dir1>[:<dir2>...]
2891 show auto-load safe-path
2892 Set a list of directories from which it is safe to auto-load files.
2893 The delimiter (':' above) may differ according to the host platform.
2895 set debug auto-load on|off
2896 show debug auto-load
2897 Control display of debugging info for auto-loading the files above.
2899 set dprintf-style gdb|call|agent
2901 Control the way in which a dynamic printf is performed; "gdb"
2902 requests a GDB printf command, while "call" causes dprintf to call a
2903 function in the inferior. "agent" requests that the target agent
2904 (such as GDBserver) do the printing.
2906 set dprintf-function <expr>
2907 show dprintf-function
2908 set dprintf-channel <expr>
2909 show dprintf-channel
2910 Set the function and optional first argument to the call when using
2911 the "call" style of dynamic printf.
2913 set disconnected-dprintf on|off
2914 show disconnected-dprintf
2915 Control whether agent-style dynamic printfs continue to be in effect
2916 after GDB disconnects.
2918 * New configure options
2920 --with-auto-load-dir
2921 Configure default value for the 'set auto-load scripts-directory'
2922 setting above. It defaults to '$debugdir:$datadir/auto-load',
2923 $debugdir representing global debugging info directories (available
2924 via 'show debug-file-directory') and $datadir representing GDB's data
2925 directory (available via 'show data-directory').
2927 --with-auto-load-safe-path
2928 Configure default value for the 'set auto-load safe-path' setting
2929 above. It defaults to the --with-auto-load-dir setting.
2931 --without-auto-load-safe-path
2932 Set 'set auto-load safe-path' to '/', effectively disabling this
2935 * New remote packets
2937 z0/z1 conditional breakpoints extension
2939 The z0/z1 breakpoint insertion packets have been extended to carry
2940 a list of conditional expressions over to the remote stub depending on the
2941 condition evaluation mode. The use of this extension can be controlled
2942 via the "set remote conditional-breakpoints-packet" command.
2946 Specify the signals which the remote stub may pass to the debugged
2947 program without GDB involvement.
2949 * New command line options
2951 --init-command=FILE, -ix Like --command, -x but execute it
2952 before loading inferior.
2953 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2954 execute it before loading inferior.
2956 *** Changes in GDB 7.4
2958 * GDB now handles ambiguous linespecs more consistently; the existing
2959 FILE:LINE support has been expanded to other types of linespecs. A
2960 breakpoint will now be set on all matching locations in all
2961 inferiors, and locations will be added or removed according to
2964 * GDB now allows you to skip uninteresting functions and files when
2965 stepping with the "skip function" and "skip file" commands.
2967 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2968 and "show remote hardware-watchpoint-length-limit". These allows to
2969 set or show the maximum length limit (in bytes) of a remote
2970 target hardware watchpoint.
2972 This allows e.g. to use "unlimited" hardware watchpoints with the
2973 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2974 watchpoints are slower than real hardware watchpoints but are
2975 significantly faster than gdb software watchpoints.
2979 ** The register_pretty_printer function in module gdb.printing now takes
2980 an optional `replace' argument. If True, the new printer replaces any
2983 ** The "maint set python print-stack on|off" command has been
2984 deprecated and will be deleted in GDB 7.5.
2985 A new command: "set python print-stack none|full|message" has
2986 replaced it. Additionally, the default for "print-stack" is
2987 now "message", which just prints the error message without
2990 ** A prompt substitution hook (prompt_hook) is now available to the
2993 ** A new Python module, gdb.prompt has been added to the GDB Python
2994 modules library. This module provides functionality for
2995 escape sequences in prompts (used by set/show
2996 extended-prompt). These escape sequences are replaced by their
2997 corresponding value.
2999 ** Python commands and convenience-functions located in
3000 'data-directory'/python/gdb/command and
3001 'data-directory'/python/gdb/function are now automatically loaded
3004 ** Blocks now provide four new attributes. global_block and
3005 static_block will return the global and static blocks
3006 respectively. is_static and is_global are boolean attributes
3007 that indicate if the block is one of those two types.
3009 ** Symbols now provide the "type" attribute, the type of the symbol.
3011 ** The "gdb.breakpoint" function has been deprecated in favor of
3014 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3015 of a function. This class is based on the "finish" command
3016 available in the CLI.
3018 ** Type objects for struct and union types now allow access to
3019 the fields using standard Python dictionary (mapping) methods.
3020 For example, "some_type['myfield']" now works, as does
3021 "some_type.items()".
3023 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3026 ** A new function, "deep_items" has been added to the gdb.types
3027 module in the GDB Python modules library. This function returns
3028 an iterator over the fields of a struct or union type. Unlike
3029 the standard Python "iteritems" method, it will recursively traverse
3030 any anonymous fields.
3034 ** "*stopped" events can report several new "reason"s, such as
3037 ** Breakpoint changes are now notified using new async records, like
3038 "=breakpoint-modified".
3040 ** New command -ada-task-info.
3042 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3043 $sdir specifies the default system locations of shared libraries.
3044 $pdir specifies the directory where the libpthread used by the application
3047 GDB no longer looks in $sdir and $pdir after it has searched the directories
3048 mentioned in libthread-db-search-path. If you want to search those
3049 directories, they must be specified in libthread-db-search-path.
3050 The default value of libthread-db-search-path on GNU/Linux and Solaris
3051 systems is now "$sdir:$pdir".
3053 $pdir is not supported by gdbserver, it is currently ignored.
3054 $sdir is supported by gdbserver.
3056 * New configure option --with-iconv-bin.
3057 When using the internationalization support like the one in the GNU C
3058 library, GDB will invoke the "iconv" program to get a list of supported
3059 character sets. If this program lives in a non-standard location, one can
3060 use this option to specify where to find it.
3062 * When natively debugging programs on PowerPC BookE processors running
3063 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3064 watchpoints, which specify a mask in addition to an address to watch.
3065 The mask specifies that some bits of an address (the bits which are
3066 reset in the mask) should be ignored when matching the address accessed
3067 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3068 section in the user manual for more details.
3070 * The new option --once causes GDBserver to stop listening for connections once
3071 the first connection is made. The listening port used by GDBserver will
3072 become available after that.
3074 * New commands "info macros" and "alias" have been added.
3076 * New function parameters suffix @entry specifies value of function parameter
3077 at the time the function got called. Entry values are available only since
3083 "!" is now an alias of the "shell" command.
3084 Note that no space is needed between "!" and SHELL COMMAND.
3088 watch EXPRESSION mask MASK_VALUE
3089 The watch command now supports the mask argument which allows creation
3090 of masked watchpoints, if the current architecture supports this feature.
3092 info auto-load-scripts [REGEXP]
3093 This command was formerly named "maintenance print section-scripts".
3094 It is now generally useful and is no longer a maintenance-only command.
3096 info macro [-all] [--] MACRO
3097 The info macro command has new options `-all' and `--'. The first for
3098 printing all definitions of a macro. The second for explicitly specifying
3099 the end of arguments and the beginning of the macro name in case the macro
3100 name starts with a hyphen.
3102 collect[/s] EXPRESSIONS
3103 The tracepoint collect command now takes an optional modifier "/s"
3104 that directs it to dereference pointer-to-character types and
3105 collect the bytes of memory up to a zero byte. The behavior is
3106 similar to what you see when you use the regular print command on a
3107 string. An optional integer following the "/s" sets a bound on the
3108 number of bytes that will be collected.
3111 The trace start command now interprets any supplied arguments as a
3112 note to be recorded with the trace run, with an effect similar to
3113 setting the variable trace-notes.
3116 The trace stop command now interprets any arguments as a note to be
3117 mentioned along with the tstatus report that the trace was stopped
3118 with a command. The effect is similar to setting the variable
3121 * Tracepoints can now be enabled and disabled at any time after a trace
3122 experiment has been started using the standard "enable" and "disable"
3123 commands. It is now possible to start a trace experiment with no enabled
3124 tracepoints; GDB will display a warning, but will allow the experiment to
3125 begin, assuming that tracepoints will be enabled as needed while the trace
3128 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3129 locations with 4-byte instructions, when they were previously
3130 limited to locations with instructions of 5 bytes or longer.
3134 set debug dwarf2-read
3135 show debug dwarf2-read
3136 Turns on or off display of debugging messages related to reading
3137 DWARF debug info. The default is off.
3139 set debug symtab-create
3140 show debug symtab-create
3141 Turns on or off display of debugging messages related to symbol table
3142 creation. The default is off.
3145 show extended-prompt
3146 Set the GDB prompt, and allow escape sequences to be inserted to
3147 display miscellaneous information (see 'help set extended-prompt'
3148 for the list of sequences). This prompt (and any information
3149 accessed through the escape sequences) is updated every time the
3150 prompt is displayed.
3152 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3153 show print entry-values
3154 Set printing of frame argument values at function entry. In some cases
3155 GDB can determine the value of function argument which was passed by the
3156 function caller, even if the value was modified inside the called function.
3158 set debug entry-values
3159 show debug entry-values
3160 Control display of debugging info for determining frame argument values at
3161 function entry and virtual tail call frames.
3163 set basenames-may-differ
3164 show basenames-may-differ
3165 Set whether a source file may have multiple base names.
3166 (A "base name" is the name of a file with the directory part removed.
3167 Example: The base name of "/home/user/hello.c" is "hello.c".)
3168 If set, GDB will canonicalize file names (e.g., expand symlinks)
3169 before comparing them. Canonicalization is an expensive operation,
3170 but it allows the same file be known by more than one base name.
3171 If not set (the default), all source files are assumed to have just
3172 one base name, and gdb will do file name comparisons more efficiently.
3178 Set a user name and notes for the current and any future trace runs.
3179 This is useful for long-running and/or disconnected traces, to
3180 inform others (or yourself) as to who is running the trace, supply
3181 contact information, or otherwise explain what is going on.
3183 set trace-stop-notes
3184 show trace-stop-notes
3185 Set a note attached to the trace run, that is displayed when the
3186 trace has been stopped by a tstop command. This is useful for
3187 instance as an explanation, if you are stopping a trace run that was
3188 started by someone else.
3190 * New remote packets
3194 Dynamically enable a tracepoint in a started trace experiment.
3198 Dynamically disable a tracepoint in a started trace experiment.
3202 Set the user and notes of the trace run.
3206 Query the current status of a tracepoint.
3210 Query the minimum length of instruction at which a fast tracepoint may
3213 * Dcache size (number of lines) and line-size are now runtime-configurable
3214 via "set dcache line" and "set dcache line-size" commands.
3218 Texas Instruments TMS320C6x tic6x-*-*
3222 Renesas RL78 rl78-*-elf
3224 *** Changes in GDB 7.3.1
3226 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3228 *** Changes in GDB 7.3
3230 * GDB has a new command: "thread find [REGEXP]".
3231 It finds the thread id whose name, target id, or thread extra info
3232 matches the given regular expression.
3234 * The "catch syscall" command now works on mips*-linux* targets.
3236 * The -data-disassemble MI command now supports modes 2 and 3 for
3237 dumping the instruction opcodes.
3239 * New command line options
3241 -data-directory DIR Specify DIR as the "data-directory".
3242 This is mostly for testing purposes.
3244 * The "maint set python auto-load on|off" command has been renamed to
3245 "set auto-load-scripts on|off".
3247 * GDB has a new command: "set directories".
3248 It is like the "dir" command except that it replaces the
3249 source path list instead of augmenting it.
3251 * GDB now understands thread names.
3253 On GNU/Linux, "info threads" will display the thread name as set by
3254 prctl or pthread_setname_np.
3256 There is also a new command, "thread name", which can be used to
3257 assign a name internally for GDB to display.
3260 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3261 has been integrated into GDB.
3265 ** The function gdb.Write now accepts an optional keyword 'stream'.
3266 This keyword, when provided, will direct the output to either
3267 stdout, stderr, or GDB's logging output.
3269 ** Parameters can now be be sub-classed in Python, and in particular
3270 you may implement the get_set_doc and get_show_doc functions.
3271 This improves how Parameter set/show documentation is processed
3272 and allows for more dynamic content.
3274 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3275 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3276 have an is_valid method.
3278 ** Breakpoints can now be sub-classed in Python, and in particular
3279 you may implement a 'stop' function that is executed each time
3280 the inferior reaches that breakpoint.
3282 ** New function gdb.lookup_global_symbol looks up a global symbol.
3284 ** GDB values in Python are now callable if the value represents a
3285 function. For example, if 'some_value' represents a function that
3286 takes two integer parameters and returns a value, you can call
3287 that function like so:
3289 result = some_value (10,20)
3291 ** Module gdb.types has been added.
3292 It contains a collection of utilities for working with gdb.Types objects:
3293 get_basic_type, has_field, make_enum_dict.
3295 ** Module gdb.printing has been added.
3296 It contains utilities for writing and registering pretty-printers.
3297 New classes: PrettyPrinter, SubPrettyPrinter,
3298 RegexpCollectionPrettyPrinter.
3299 New function: register_pretty_printer.
3301 ** New commands "info pretty-printers", "enable pretty-printer" and
3302 "disable pretty-printer" have been added.
3304 ** gdb.parameter("directories") is now available.
3306 ** New function gdb.newest_frame returns the newest frame in the
3309 ** The gdb.InferiorThread class has a new "name" attribute. This
3310 holds the thread's name.
3312 ** Python Support for Inferior events.
3313 Python scripts can add observers to be notified of events
3314 occurring in the process being debugged.
3315 The following events are currently supported:
3316 - gdb.events.cont Continue event.
3317 - gdb.events.exited Inferior exited event.
3318 - gdb.events.stop Signal received, and Breakpoint hit events.
3322 ** GDB now puts template parameters in scope when debugging in an
3323 instantiation. For example, if you have:
3325 template<int X> int func (void) { return X; }
3327 then if you step into func<5>, "print X" will show "5". This
3328 feature requires proper debuginfo support from the compiler; it
3329 was added to GCC 4.5.
3331 ** The motion commands "next", "finish", "until", and "advance" now
3332 work better when exceptions are thrown. In particular, GDB will
3333 no longer lose control of the inferior; instead, the GDB will
3334 stop the inferior at the point at which the exception is caught.
3335 This functionality requires a change in the exception handling
3336 code that was introduced in GCC 4.5.
3338 * GDB now follows GCC's rules on accessing volatile objects when
3339 reading or writing target state during expression evaluation.
3340 One notable difference to prior behavior is that "print x = 0"
3341 no longer generates a read of x; the value of the assignment is
3342 now always taken directly from the value being assigned.
3344 * GDB now has some support for using labels in the program's source in
3345 linespecs. For instance, you can use "advance label" to continue
3346 execution to a label.
3348 * GDB now has support for reading and writing a new .gdb_index
3349 section. This section holds a fast index of DWARF debugging
3350 information and can be used to greatly speed up GDB startup and
3351 operation. See the documentation for `save gdb-index' for details.
3353 * The "watch" command now accepts an optional "-location" argument.
3354 When used, this causes GDB to watch the memory referred to by the
3355 expression. Such a watchpoint is never deleted due to it going out
3358 * GDB now supports thread debugging of core dumps on GNU/Linux.
3360 GDB now activates thread debugging using the libthread_db library
3361 when debugging GNU/Linux core dumps, similarly to when debugging
3362 live processes. As a result, when debugging a core dump file, GDB
3363 is now able to display pthread_t ids of threads. For example, "info
3364 threads" shows the same output as when debugging the process when it
3365 was live. In earlier releases, you'd see something like this:
3368 * 1 LWP 6780 main () at main.c:10
3370 While now you see this:
3373 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3375 It is also now possible to inspect TLS variables when debugging core
3378 When debugging a core dump generated on a machine other than the one
3379 used to run GDB, you may need to point GDB at the correct
3380 libthread_db library with the "set libthread-db-search-path"
3381 command. See the user manual for more details on this command.
3383 * When natively debugging programs on PowerPC BookE processors running
3384 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3385 which stop execution of the inferior whenever it executes an instruction
3386 at any address within the specified range. See the "PowerPC Embedded"
3387 section in the user manual for more details.
3389 * New features in the GDB remote stub, GDBserver
3391 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3392 and i686 LynxOS (version 5.x).
3394 ** GDBserver is now supported on Blackfin Linux.
3396 * New native configurations
3398 ia64 HP-UX ia64-*-hpux*
3402 Analog Devices, Inc. Blackfin Processor bfin-*
3404 * Ada task switching is now supported on sparc-elf targets when
3405 debugging a program using the Ravenscar Profile. For more information,
3406 see the "Tasking Support when using the Ravenscar Profile" section
3407 in the GDB user manual.
3409 * Guile support was removed.
3411 * New features in the GNU simulator
3413 ** The --map-info flag lists all known core mappings.
3415 ** CFI flashes may be simulated via the "cfi" device.
3417 *** Changes in GDB 7.2
3419 * Shared library support for remote targets by default
3421 When GDB is configured for a generic, non-OS specific target, like
3422 for example, --target=arm-eabi or one of the many *-*-elf targets,
3423 GDB now queries remote stubs for loaded shared libraries using the
3424 `qXfer:libraries:read' packet. Previously, shared library support
3425 was always disabled for such configurations.
3429 ** Argument Dependent Lookup (ADL)
3431 In C++ ADL lookup directs function search to the namespaces of its
3432 arguments even if the namespace has not been imported.
3442 Here the compiler will search for `foo' in the namespace of 'b'
3443 and find A::foo. GDB now supports this. This construct is commonly
3444 used in the Standard Template Library for operators.
3446 ** Improved User Defined Operator Support
3448 In addition to member operators, GDB now supports lookup of operators
3449 defined in a namespace and imported with a `using' directive, operators
3450 defined in the global scope, operators imported implicitly from an
3451 anonymous namespace, and the ADL operators mentioned in the previous
3453 GDB now also supports proper overload resolution for all the previously
3454 mentioned flavors of operators.
3456 ** static const class members
3458 Printing of static const class members that are initialized in the
3459 class definition has been fixed.
3461 * Windows Thread Information Block access.
3463 On Windows targets, GDB now supports displaying the Windows Thread
3464 Information Block (TIB) structure. This structure is visible either
3465 by using the new command `info w32 thread-information-block' or, by
3466 dereferencing the new convenience variable named `$_tlb', a
3467 thread-specific pointer to the TIB. This feature is also supported
3468 when remote debugging using GDBserver.
3470 * Static tracepoints
3472 Static tracepoints are calls in the user program into a tracing
3473 library. One such library is a port of the LTTng kernel tracer to
3474 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3475 When debugging with GDBserver, GDB now supports combining the GDB
3476 tracepoint machinery with such libraries. For example: the user can
3477 use GDB to probe a static tracepoint marker (a call from the user
3478 program into the tracing library) with the new "strace" command (see
3479 "New commands" below). This creates a "static tracepoint" in the
3480 breakpoint list, that can be manipulated with the same feature set
3481 as fast and regular tracepoints. E.g., collect registers, local and
3482 global variables, collect trace state variables, and define
3483 tracepoint conditions. In addition, the user can collect extra
3484 static tracepoint marker specific data, by collecting the new
3485 $_sdata internal variable. When analyzing the trace buffer, you can
3486 inspect $_sdata like any other variable available to GDB. For more
3487 information, see the "Tracepoints" chapter in GDB user manual. New
3488 remote packets have been defined to support static tracepoints, see
3489 the "New remote packets" section below.
3491 * Better reconstruction of tracepoints after disconnected tracing
3493 GDB will attempt to download the original source form of tracepoint
3494 definitions when starting a trace run, and then will upload these
3495 upon reconnection to the target, resulting in a more accurate
3496 reconstruction of the tracepoints that are in use on the target.
3500 You can now exercise direct control over the ways that GDB can
3501 affect your program. For instance, you can disallow the setting of
3502 breakpoints, so that the program can run continuously (assuming
3503 non-stop mode). In addition, the "observer" variable is available
3504 to switch all of the different controls; in observer mode, GDB
3505 cannot affect the target's behavior at all, which is useful for
3506 tasks like diagnosing live systems in the field.
3508 * The new convenience variable $_thread holds the number of the
3511 * New remote packets
3515 Return the address of the Windows Thread Information Block of a given thread.
3519 In response to several of the tracepoint packets, the target may now
3520 also respond with a number of intermediate `qRelocInsn' request
3521 packets before the final result packet, to have GDB handle
3522 relocating an instruction to execute at a different address. This
3523 is particularly useful for stubs that support fast tracepoints. GDB
3524 reports support for this feature in the qSupported packet.
3528 List static tracepoint markers in the target program.
3532 List static tracepoint markers at a given address in the target
3535 qXfer:statictrace:read
3537 Read the static trace data collected (by a `collect $_sdata'
3538 tracepoint action). The remote stub reports support for this packet
3539 to gdb's qSupported query.
3543 Send the current settings of GDB's permission flags.
3547 Send part of the source (textual) form of a tracepoint definition,
3548 which includes location, conditional, and action list.
3550 * The source command now accepts a -s option to force searching for the
3551 script in the source search path even if the script name specifies
3554 * New features in the GDB remote stub, GDBserver
3556 - GDBserver now support tracepoints (including fast tracepoints, and
3557 static tracepoints). The feature is currently supported by the
3558 i386-linux and amd64-linux builds. See the "Tracepoints support
3559 in gdbserver" section in the manual for more information.
3561 GDBserver JIT compiles the tracepoint's conditional agent
3562 expression bytecode into native code whenever possible for low
3563 overhead dynamic tracepoints conditionals. For such tracepoints,
3564 an expression that examines program state is evaluated when the
3565 tracepoint is reached, in order to determine whether to capture
3566 trace data. If the condition is simple and false, processing the
3567 tracepoint finishes very quickly and no data is gathered.
3569 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3570 for static tracepoints support.
3572 - GDBserver now supports x86_64 Windows 64-bit debugging.
3574 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3575 it understands register description.
3577 * The --batch flag now disables pagination and queries.
3579 * X86 general purpose registers
3581 GDB now supports reading/writing byte, word and double-word x86
3582 general purpose registers directly. This means you can use, say,
3583 $ah or $ax to refer, respectively, to the byte register AH and
3584 16-bit word register AX that are actually portions of the 32-bit
3585 register EAX or 64-bit register RAX.
3587 * The `commands' command now accepts a range of breakpoints to modify.
3588 A plain `commands' following a command that creates multiple
3589 breakpoints affects all the breakpoints set by that command. This
3590 applies to breakpoints set by `rbreak', and also applies when a
3591 single `break' command creates multiple breakpoints (e.g.,
3592 breakpoints on overloaded c++ functions).
3594 * The `rbreak' command now accepts a filename specification as part of
3595 its argument, limiting the functions selected by the regex to those
3596 in the specified file.
3598 * Support for remote debugging Windows and SymbianOS shared libraries
3599 from Unix hosts has been improved. Non Windows GDB builds now can
3600 understand target reported file names that follow MS-DOS based file
3601 system semantics, such as file names that include drive letters and
3602 use the backslash character as directory separator. This makes it
3603 possible to transparently use the "set sysroot" and "set
3604 solib-search-path" on Unix hosts to point as host copies of the
3605 target's shared libraries. See the new command "set
3606 target-file-system-kind" described below, and the "Commands to
3607 specify files" section in the user manual for more information.
3611 eval template, expressions...
3612 Convert the values of one or more expressions under the control
3613 of the string template to a command line, and call it.
3615 set target-file-system-kind unix|dos-based|auto
3616 show target-file-system-kind
3617 Set or show the assumed file system kind for target reported file
3620 save breakpoints <filename>
3621 Save all current breakpoint definitions to a file suitable for use
3622 in a later debugging session. To read the saved breakpoint
3623 definitions, use the `source' command.
3625 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3628 info static-tracepoint-markers
3629 Display information about static tracepoint markers in the target.
3631 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3632 Define a static tracepoint by probing a marker at the given
3633 function, line, address, or marker ID.
3637 Enable and disable observer mode.
3639 set may-write-registers on|off
3640 set may-write-memory on|off
3641 set may-insert-breakpoints on|off
3642 set may-insert-tracepoints on|off
3643 set may-insert-fast-tracepoints on|off
3644 set may-interrupt on|off
3645 Set individual permissions for GDB effects on the target. Note that
3646 some of these settings can have undesirable or surprising
3647 consequences, particularly when changed in the middle of a session.
3648 For instance, disabling the writing of memory can prevent
3649 breakpoints from being inserted, cause single-stepping to fail, or
3650 even crash your program, if you disable after breakpoints have been
3651 inserted. However, GDB should not crash.
3653 set record memory-query on|off
3654 show record memory-query
3655 Control whether to stop the inferior if memory changes caused
3656 by an instruction cannot be recorded.
3661 The disassemble command now supports "start,+length" form of two arguments.
3665 ** GDB now provides a new directory location, called the python directory,
3666 where Python scripts written for GDB can be installed. The location
3667 of that directory is <data-directory>/python, where <data-directory>
3668 is the GDB data directory. For more details, see section `Scripting
3669 GDB using Python' in the manual.
3671 ** The GDB Python API now has access to breakpoints, symbols, symbol
3672 tables, program spaces, inferiors, threads and frame's code blocks.
3673 Additionally, GDB Parameters can now be created from the API, and
3674 manipulated via set/show in the CLI.
3676 ** New functions gdb.target_charset, gdb.target_wide_charset,
3677 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3679 ** New exception gdb.GdbError.
3681 ** Pretty-printers are now also looked up in the current program space.
3683 ** Pretty-printers can now be individually enabled and disabled.
3685 ** GDB now looks for names of Python scripts to auto-load in a
3686 special section named `.debug_gdb_scripts', in addition to looking
3687 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3689 * Tracepoint actions were unified with breakpoint commands. In particular,
3690 there are no longer differences in "info break" output for breakpoints and
3691 tracepoints and the "commands" command can be used for both tracepoints and
3692 regular breakpoints.
3696 ARM Symbian arm*-*-symbianelf*
3698 * D language support.
3699 GDB now supports debugging programs written in the D programming
3702 * GDB now supports the extended ptrace interface for PowerPC which is
3703 available since Linux kernel version 2.6.34. This automatically enables
3704 any hardware breakpoints and additional hardware watchpoints available in
3705 the processor. The old ptrace interface exposes just one hardware
3706 watchpoint and no hardware breakpoints.
3708 * GDB is now able to use the Data Value Compare (DVC) register available on
3709 embedded PowerPC processors to implement in hardware simple watchpoint
3710 conditions of the form:
3712 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3714 This works in native GDB running on Linux kernels with the extended ptrace
3715 interface mentioned above.
3717 *** Changes in GDB 7.1
3721 ** Namespace Support
3723 GDB now supports importing of namespaces in C++. This enables the
3724 user to inspect variables from imported namespaces. Support for
3725 namepace aliasing has also been added. So, if a namespace is
3726 aliased in the current scope (e.g. namepace C=A; ) the user can
3727 print variables using the alias (e.g. (gdb) print C::x).
3731 All known bugs relating to the printing of virtual base class were
3732 fixed. It is now possible to call overloaded static methods using a
3737 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3738 and reinterpret_cast<> are now handled by the C++ expression parser.
3742 Xilinx MicroBlaze microblaze-*-*
3747 Xilinx MicroBlaze microblaze
3750 * Multi-program debugging.
3752 GDB now has support for multi-program (a.k.a. multi-executable or
3753 multi-exec) debugging. This allows for debugging multiple inferiors
3754 simultaneously each running a different program under the same GDB
3755 session. See "Debugging Multiple Inferiors and Programs" in the
3756 manual for more information. This implied some user visible changes
3757 in the multi-inferior support. For example, "info inferiors" now
3758 lists inferiors that are not running yet or that have exited
3759 already. See also "New commands" and "New options" below.
3761 * New tracing features
3763 GDB's tracepoint facility now includes several new features:
3765 ** Trace state variables
3767 GDB tracepoints now include support for trace state variables, which
3768 are variables managed by the target agent during a tracing
3769 experiment. They are useful for tracepoints that trigger each
3770 other, so for instance one tracepoint can count hits in a variable,
3771 and then a second tracepoint has a condition that is true when the
3772 count reaches a particular value. Trace state variables share the
3773 $-syntax of GDB convenience variables, and can appear in both
3774 tracepoint actions and condition expressions. Use the "tvariable"
3775 command to create, and "info tvariables" to view; see "Trace State
3776 Variables" in the manual for more detail.
3780 GDB now includes an option for defining fast tracepoints, which
3781 targets may implement more efficiently, such as by installing a jump
3782 into the target agent rather than a trap instruction. The resulting
3783 speedup can be by two orders of magnitude or more, although the
3784 tradeoff is that some program locations on some target architectures
3785 might not allow fast tracepoint installation, for instance if the
3786 instruction to be replaced is shorter than the jump. To request a
3787 fast tracepoint, use the "ftrace" command, with syntax identical to
3788 the regular trace command.
3790 ** Disconnected tracing
3792 It is now possible to detach GDB from the target while it is running
3793 a trace experiment, then reconnect later to see how the experiment
3794 is going. In addition, a new variable disconnected-tracing lets you
3795 tell the target agent whether to continue running a trace if the
3796 connection is lost unexpectedly.
3800 GDB now has the ability to save the trace buffer into a file, and
3801 then use that file as a target, similarly to you can do with
3802 corefiles. You can select trace frames, print data that was
3803 collected in them, and use tstatus to display the state of the
3804 tracing run at the moment that it was saved. To create a trace
3805 file, use "tsave <filename>", and to use it, do "target tfile
3808 ** Circular trace buffer
3810 You can ask the target agent to handle the trace buffer as a
3811 circular buffer, discarding the oldest trace frames to make room for
3812 newer ones, by setting circular-trace-buffer to on. This feature may
3813 not be available for all target agents.
3818 The disassemble command, when invoked with two arguments, now requires
3819 the arguments to be comma-separated.
3822 The info variables command now displays variable definitions. Files
3823 which only declare a variable are not shown.
3826 The source command is now capable of sourcing Python scripts.
3827 This feature is dependent on the debugger being build with Python
3830 Related to this enhancement is also the introduction of a new command
3831 "set script-extension" (see below).
3833 * New commands (for set/show, see "New options" below)
3835 record save [<FILENAME>]
3836 Save a file (in core file format) containing the process record
3837 execution log for replay debugging at a later time.
3839 record restore <FILENAME>
3840 Restore the process record execution log that was saved at an
3841 earlier time, for replay debugging.
3843 add-inferior [-copies <N>] [-exec <FILENAME>]
3846 clone-inferior [-copies <N>] [ID]
3847 Make a new inferior ready to execute the same program another
3848 inferior has loaded.
3853 maint info program-spaces
3854 List the program spaces loaded into GDB.
3856 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3857 show remote interrupt-sequence
3858 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3859 as the sequence to the remote target in order to interrupt the execution.
3860 Ctrl-C is a default. Some system prefers BREAK which is high level of
3861 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3862 Magic SysRq g. It is BREAK signal and character 'g'.
3864 set remote interrupt-on-connect [on | off]
3865 show remote interrupt-on-connect
3866 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3867 remote target when gdb connects to it. This is needed when you debug
3870 set remotebreak [on | off]
3872 Deprecated. Use "set/show remote interrupt-sequence" instead.
3874 tvariable $NAME [ = EXP ]
3875 Create or modify a trace state variable.
3878 List trace state variables and their values.
3880 delete tvariable $NAME ...
3881 Delete one or more trace state variables.
3884 Evaluate the given expressions without collecting anything into the
3885 trace buffer. (Valid in tracepoint actions only.)
3887 ftrace FN / FILE:LINE / *ADDR
3888 Define a fast tracepoint at the given function, line, or address.
3890 * New expression syntax
3892 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3893 GDB now parses 0b101010 identically with 42.
3897 set follow-exec-mode new|same
3898 show follow-exec-mode
3899 Control whether GDB reuses the same inferior across an exec call or
3900 creates a new one. This is useful to be able to restart the old
3901 executable after the inferior having done an exec call.
3903 set default-collect EXPR, ...
3904 show default-collect
3905 Define a list of expressions to be collected at each tracepoint.
3906 This is a useful way to ensure essential items are not overlooked,
3907 such as registers or a critical global variable.
3909 set disconnected-tracing
3910 show disconnected-tracing
3911 If set to 1, the target is instructed to continue tracing if it
3912 loses its connection to GDB. If 0, the target is to stop tracing
3915 set circular-trace-buffer
3916 show circular-trace-buffer
3917 If set to on, the target is instructed to use a circular trace buffer
3918 and discard the oldest trace frames instead of stopping the trace due
3919 to a full trace buffer. If set to off, the trace stops when the buffer
3920 fills up. Some targets may not support this.
3922 set script-extension off|soft|strict
3923 show script-extension
3924 If set to "off", the debugger does not perform any script language
3925 recognition, and all sourced files are assumed to be GDB scripts.
3926 If set to "soft" (the default), files are sourced according to
3927 filename extension, falling back to GDB scripts if the first
3929 If set to "strict", files are sourced according to filename extension.
3931 set ada trust-PAD-over-XVS on|off
3932 show ada trust-PAD-over-XVS
3933 If off, activate a workaround against a bug in the debugging information
3934 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3935 the GCC sources for more information about the GNAT encoding and
3936 PAD types in particular). It is always safe to set this option to
3937 off, but this introduces a slight performance penalty. The default
3940 * Python API Improvements
3942 ** GDB provides the new class gdb.LazyString. This is useful in
3943 some pretty-printing cases. The new method gdb.Value.lazy_string
3944 provides a simple way to create objects of this type.
3946 ** The fields returned by gdb.Type.fields now have an
3947 `is_base_class' attribute.
3949 ** The new method gdb.Type.range returns the range of an array type.
3951 ** The new method gdb.parse_and_eval can be used to parse and
3952 evaluate an expression.
3954 * New remote packets
3957 Define a trace state variable.
3960 Get the current value of a trace state variable.
3963 Set desired tracing behavior upon disconnection.
3966 Set the trace buffer to be linear or circular.
3969 Get data about the tracepoints currently in use.
3973 Process record now works correctly with hardware watchpoints.
3975 Multiple bug fixes have been made to the mips-irix port, making it
3976 much more reliable. In particular:
3977 - Debugging threaded applications is now possible again. Previously,
3978 GDB would hang while starting the program, or while waiting for
3979 the program to stop at a breakpoint.
3980 - Attaching to a running process no longer hangs.
3981 - An error occurring while loading a core file has been fixed.
3982 - Changing the value of the PC register now works again. This fixes
3983 problems observed when using the "jump" command, or when calling
3984 a function from GDB, or even when assigning a new value to $pc.
3985 - With the "finish" and "return" commands, the return value for functions
3986 returning a small array is now correctly printed.
3987 - It is now possible to break on shared library code which gets executed
3988 during a shared library init phase (code executed while executing
3989 their .init section). Previously, the breakpoint would have no effect.
3990 - GDB is now able to backtrace through the signal handler for
3991 non-threaded programs.
3993 PIE (Position Independent Executable) programs debugging is now supported.
3994 This includes debugging execution of PIC (Position Independent Code) shared
3995 libraries although for that, it should be possible to run such libraries as an
3998 *** Changes in GDB 7.0
4000 * GDB now has an interface for JIT compilation. Applications that
4001 dynamically generate code can create symbol files in memory and register
4002 them with GDB. For users, the feature should work transparently, and
4003 for JIT developers, the interface is documented in the GDB manual in the
4004 "JIT Compilation Interface" chapter.
4006 * Tracepoints may now be conditional. The syntax is as for
4007 breakpoints; either an "if" clause appended to the "trace" command,
4008 or the "condition" command is available. GDB sends the condition to
4009 the target for evaluation using the same bytecode format as is used
4010 for tracepoint actions.
4012 * The disassemble command now supports: an optional /r modifier, print the
4013 raw instructions in hex as well as in symbolic form, and an optional /m
4014 modifier to print mixed source+assembly.
4016 * Process record and replay
4018 In a architecture environment that supports ``process record and
4019 replay'', ``process record and replay'' target can record a log of
4020 the process execution, and replay it with both forward and reverse
4023 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4024 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4025 set execution-direction {forward|reverse}, for targets that support
4028 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4029 feature is available with a native GDB running on kernel version
4032 * GDB now has support for multi-byte and wide character sets on the
4033 target. Strings whose character type is wchar_t, char16_t, or
4034 char32_t are now correctly printed. GDB supports wide- and unicode-
4035 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4036 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4037 `printf'. This feature requires iconv to work properly; if your
4038 system does not have a working iconv, GDB can use GNU libiconv. See
4039 the installation instructions for more information.
4041 * GDB now supports automatic retrieval of shared library files from
4042 remote targets. To use this feature, specify a system root that begins
4043 with the `remote:' prefix, either via the `set sysroot' command or via
4044 the `--with-sysroot' configure-time option.
4046 * "info sharedlibrary" now takes an optional regex of libraries to show,
4047 and it now reports if a shared library has no debugging information.
4049 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4050 now complete on file names.
4052 * When completing in expressions, gdb will attempt to limit
4053 completions to allowable structure or union fields, where appropriate.
4054 For instance, consider:
4056 # struct example { int f1; double f2; };
4057 # struct example variable;
4060 If the user types TAB at the end of this command line, the available
4061 completions will be "f1" and "f2".
4063 * Inlined functions are now supported. They show up in backtraces, and
4064 the "step", "next", and "finish" commands handle them automatically.
4066 * GDB now supports the token-splicing (##) and stringification (#)
4067 operators when expanding macros. It also supports variable-arity
4070 * GDB now supports inspecting extra signal information, exported by
4071 the new $_siginfo convenience variable. The feature is currently
4072 implemented on linux ARM, i386 and amd64.
4074 * GDB can now display the VFP floating point registers and NEON vector
4075 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4076 can provide these registers (requires Linux 2.6.30 or later). Remote
4077 and simulator targets may also provide them.
4079 * New remote packets
4082 Search memory for a sequence of bytes.
4085 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4086 operation over reliable transport links. Use of this packet is
4087 controlled by the `set remote noack-packet' command.
4090 Kill the process with the specified process ID. Use this in preference
4091 to `k' when multiprocess protocol extensions are supported.
4094 Obtains additional operating system information
4098 Read or write additional signal information.
4100 * Removed remote protocol undocumented extension
4102 An undocumented extension to the remote protocol's `S' stop reply
4103 packet that permited the stub to pass a process id was removed.
4104 Remote servers should use the `T' stop reply packet instead.
4106 * GDB now supports multiple function calling conventions according to the
4107 DWARF-2 DW_AT_calling_convention function attribute.
4109 * The SH target utilizes the aforementioned change to distinguish between gcc
4110 and Renesas calling convention. It also adds the new CLI commands
4111 `set/show sh calling-convention'.
4113 * GDB can now read compressed debug sections, as produced by GNU gold
4114 with the --compress-debug-sections=zlib flag.
4116 * 64-bit core files are now supported on AIX.
4118 * Thread switching is now supported on Tru64.
4120 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4121 which will be allocated using malloc later in program execution.
4123 * The qXfer:libraries:read remote procotol packet now allows passing a
4124 list of section offsets.
4126 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4127 conditions handling signals delivered during attach or thread creation
4128 have also been fixed.
4130 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4131 From the user's standpoint, all unqualified instances of True and False
4132 are treated as the standard definitions, regardless of context.
4134 * GDB now parses C++ symbol and type names more flexibly. For
4137 template<typename T> class C { };
4140 GDB will now correctly handle all of:
4142 ptype C<char const *>
4143 ptype C<char const*>
4144 ptype C<const char *>
4145 ptype C<const char*>
4147 * New features in the GDB remote stub, gdbserver
4149 - The "--wrapper" command-line argument tells gdbserver to use a
4150 wrapper program to launch programs for debugging.
4152 - On PowerPC and S/390 targets, it is now possible to use a single
4153 gdbserver executable to debug both 32-bit and 64-bit programs.
4154 (This requires gdbserver itself to be built as a 64-bit executable.)
4156 - gdbserver uses the new noack protocol mode for TCP connections to
4157 reduce communications latency, if also supported and enabled in GDB.
4159 - Support for the sparc64-linux-gnu target is now included in
4162 - The amd64-linux build of gdbserver now supports debugging both
4163 32-bit and 64-bit programs.
4165 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4166 now support hardware watchpoints, and will use them automatically
4171 GDB now has support for scripting using Python. Whether this is
4172 available is determined at configure time.
4174 New GDB commands can now be written in Python.
4176 * Ada tasking support
4178 Ada tasks can now be inspected in GDB. The following commands have
4182 Print the list of Ada tasks.
4184 Print detailed information about task number N.
4186 Print the task number of the current task.
4188 Switch the context of debugging to task number N.
4190 * Support for user-defined prefixed commands. The "define" command can
4191 add new commands to existing prefixes, e.g. "target".
4193 * Multi-inferior, multi-process debugging.
4195 GDB now has generalized support for multi-inferior debugging. See
4196 "Debugging Multiple Inferiors" in the manual for more information.
4197 Although availability still depends on target support, the command
4198 set is more uniform now. The GNU/Linux specific multi-forks support
4199 has been migrated to this new framework. This implied some user
4200 visible changes; see "New commands" and also "Removed commands"
4203 * Target descriptions can now describe the target OS ABI. See the
4204 "Target Description Format" section in the user manual for more
4207 * Target descriptions can now describe "compatible" architectures
4208 to indicate that the target can execute applications for a different
4209 architecture in addition to those for the main target architecture.
4210 See the "Target Description Format" section in the user manual for
4213 * Multi-architecture debugging.
4215 GDB now includes general supports for debugging applications on
4216 hybrid systems that use more than one single processor architecture
4217 at the same time. Each such hybrid architecture still requires
4218 specific support to be added. The only hybrid architecture supported
4219 in this version of GDB is the Cell Broadband Engine.
4221 * GDB now supports integrated debugging of Cell/B.E. applications that
4222 use both the PPU and SPU architectures. To enable support for hybrid
4223 Cell/B.E. debugging, you need to configure GDB to support both the
4224 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4225 --enable-targets configure option.
4227 * Non-stop mode debugging.
4229 For some targets, GDB now supports an optional mode of operation in
4230 which you can examine stopped threads while other threads continue
4231 to execute freely. This is referred to as non-stop mode, with the
4232 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4233 section in the user manual for more information.
4235 To be able to support remote non-stop debugging, a remote stub needs
4236 to implement the non-stop mode remote protocol extensions, as
4237 described in the "Remote Non-Stop" section of the user manual. The
4238 GDB remote stub, gdbserver, has been adjusted to support these
4239 extensions on linux targets.
4241 * New commands (for set/show, see "New options" below)
4243 catch syscall [NAME(S) | NUMBER(S)]
4244 Catch system calls. Arguments, which should be names of system
4245 calls or their numbers, mean catch only those syscalls. Without
4246 arguments, every syscall will be caught. When the inferior issues
4247 any of the specified syscalls, GDB will stop and announce the system
4248 call, both when it is called and when its call returns. This
4249 feature is currently available with a native GDB running on the
4250 Linux Kernel, under the following architectures: x86, x86_64,
4251 PowerPC and PowerPC64.
4253 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4255 Search memory for a sequence of bytes.
4257 maint set python print-stack
4258 maint show python print-stack
4259 Show a stack trace when an error is encountered in a Python script.
4262 Invoke CODE by passing it to the Python interpreter.
4267 These allow macros to be defined, undefined, and listed
4271 Show operating system information about processes.
4274 List the inferiors currently under GDB's control.
4277 Switch focus to inferior number NUM.
4280 Detach from inferior number NUM.
4283 Kill inferior number NUM.
4287 set spu stop-on-load
4288 show spu stop-on-load
4289 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4291 set spu auto-flush-cache
4292 show spu auto-flush-cache
4293 Control whether to automatically flush the software-managed cache
4294 during Cell/B.E. debugging.
4296 set sh calling-convention
4297 show sh calling-convention
4298 Control the calling convention used when calling SH target functions.
4301 show debug timestamp
4302 Control display of timestamps with GDB debugging output.
4304 set disassemble-next-line
4305 show disassemble-next-line
4306 Control display of disassembled source lines or instructions when
4309 set remote noack-packet
4310 show remote noack-packet
4311 Set/show the use of remote protocol QStartNoAckMode packet. See above
4312 under "New remote packets."
4314 set remote query-attached-packet
4315 show remote query-attached-packet
4316 Control use of remote protocol `qAttached' (query-attached) packet.
4318 set remote read-siginfo-object
4319 show remote read-siginfo-object
4320 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4323 set remote write-siginfo-object
4324 show remote write-siginfo-object
4325 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4328 set remote reverse-continue
4329 show remote reverse-continue
4330 Control use of remote protocol 'bc' (reverse-continue) packet.
4332 set remote reverse-step
4333 show remote reverse-step
4334 Control use of remote protocol 'bs' (reverse-step) packet.
4336 set displaced-stepping
4337 show displaced-stepping
4338 Control displaced stepping mode. Displaced stepping is a way to
4339 single-step over breakpoints without removing them from the debuggee.
4340 Also known as "out-of-line single-stepping".
4343 show debug displaced
4344 Control display of debugging info for displaced stepping.
4346 maint set internal-error
4347 maint show internal-error
4348 Control what GDB does when an internal error is detected.
4350 maint set internal-warning
4351 maint show internal-warning
4352 Control what GDB does when an internal warning is detected.
4357 Use a wrapper program to launch programs for debugging.
4359 set multiple-symbols (all|ask|cancel)
4360 show multiple-symbols
4361 The value of this variable can be changed to adjust the debugger behavior
4362 when an expression or a breakpoint location contains an ambiguous symbol
4363 name (an overloaded function name, for instance).
4365 set breakpoint always-inserted
4366 show breakpoint always-inserted
4367 Keep breakpoints always inserted in the target, as opposed to inserting
4368 them when resuming the target, and removing them when the target stops.
4369 This option can improve debugger performance on slow remote targets.
4371 set arm fallback-mode (arm|thumb|auto)
4372 show arm fallback-mode
4373 set arm force-mode (arm|thumb|auto)
4375 These commands control how ARM GDB determines whether instructions
4376 are ARM or Thumb. The default for both settings is auto, which uses
4377 the current CPSR value for instructions without symbols; previous
4378 versions of GDB behaved as if "set arm fallback-mode arm".
4380 set disable-randomization
4381 show disable-randomization
4382 Standalone programs run with the virtual address space randomization enabled
4383 by default on some platforms. This option keeps the addresses stable across
4384 multiple debugging sessions.
4388 Control whether other threads are stopped or not when some thread hits
4393 Requests that asynchronous execution is enabled in the target, if available.
4394 In this case, it's possible to resume target in the background, and interact
4395 with GDB while the target is running. "show target-async" displays the
4396 current state of asynchronous execution of the target.
4398 set target-wide-charset
4399 show target-wide-charset
4400 The target-wide-charset is the name of the character set that GDB
4401 uses when printing characters whose type is wchar_t.
4403 set tcp auto-retry (on|off)
4405 set tcp connect-timeout
4406 show tcp connect-timeout
4407 These commands allow GDB to retry failed TCP connections to a remote stub
4408 with a specified timeout period; this is useful if the stub is launched
4409 in parallel with GDB but may not be ready to accept connections immediately.
4411 set libthread-db-search-path
4412 show libthread-db-search-path
4413 Control list of directories which GDB will search for appropriate
4416 set schedule-multiple (on|off)
4417 show schedule-multiple
4418 Allow GDB to resume all threads of all processes or only threads of
4419 the current process.
4423 Use more aggressive caching for accesses to the stack. This improves
4424 performance of remote debugging (particularly backtraces) without
4425 affecting correctness.
4427 set interactive-mode (on|off|auto)
4428 show interactive-mode
4429 Control whether GDB runs in interactive mode (on) or not (off).
4430 When in interactive mode, GDB waits for the user to answer all
4431 queries. Otherwise, GDB does not wait and assumes the default
4432 answer. When set to auto (the default), GDB determines which
4433 mode to use based on the stdin settings.
4438 For program forks, this is replaced by the new more generic `info
4439 inferiors' command. To list checkpoints, you can still use the
4440 `info checkpoints' command, which was an alias for the `info forks'
4444 Replaced by the new `inferior' command. To switch between
4445 checkpoints, you can still use the `restart' command, which was an
4446 alias for the `fork' command.
4449 This is removed, since some targets don't have a notion of
4450 processes. To switch between processes, you can still use the
4451 `inferior' command using GDB's own inferior number.
4454 For program forks, this is replaced by the new more generic `kill
4455 inferior' command. To delete a checkpoint, you can still use the
4456 `delete checkpoint' command, which was an alias for the `delete
4460 For program forks, this is replaced by the new more generic `detach
4461 inferior' command. To detach a checkpoint, you can still use the
4462 `detach checkpoint' command, which was an alias for the `detach
4465 * New native configurations
4467 x86/x86_64 Darwin i[34567]86-*-darwin*
4469 x86_64 MinGW x86_64-*-mingw*
4473 Lattice Mico32 lm32-*
4474 x86 DICOS i[34567]86-*-dicos*
4475 x86_64 DICOS x86_64-*-dicos*
4478 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4479 (mingw32ce) debugging.
4485 These commands were actually not implemented on any target.
4487 *** Changes in GDB 6.8
4489 * New native configurations
4491 NetBSD/hppa hppa*-*netbsd*
4492 Xtensa GNU/Linux xtensa*-*-linux*
4496 NetBSD/hppa hppa*-*-netbsd*
4497 Xtensa GNU/Lunux xtensa*-*-linux*
4499 * Change in command line behavior -- corefiles vs. process ids.
4501 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4502 attaching to process NUMBER fails, GDB no longer attempts to open a
4503 core file named NUMBER. Attaching to a program using the -c option
4504 is no longer supported. Instead, use the '-p' or '--pid' options.
4506 * GDB can now be built as a native debugger for debugging Windows x86
4507 (mingw32) Portable Executable (PE) programs.
4509 * Pending breakpoints no longer change their number when their address
4512 * GDB now supports breakpoints with multiple locations,
4513 including breakpoints on C++ constructors, inside C++ templates,
4514 and in inlined functions.
4516 * GDB's ability to debug optimized code has been improved. GDB more
4517 accurately identifies function bodies and lexical blocks that occupy
4518 more than one contiguous range of addresses.
4520 * Target descriptions can now describe registers for PowerPC.
4522 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4523 registers on PowerPC targets.
4525 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4526 targets even when the libthread_db library is not available.
4528 * The GDB remote stub, gdbserver, now supports the new file transfer
4529 commands (remote put, remote get, and remote delete).
4531 * The GDB remote stub, gdbserver, now supports run and attach in
4532 extended-remote mode.
4534 * hppa*64*-*-hpux11* target broken
4535 The debugger is unable to start a program and fails with the following
4536 error: "Error trying to get information about dynamic linker".
4537 The gdb-6.7 release is also affected.
4539 * GDB now supports the --enable-targets= configure option to allow
4540 building a single GDB executable that supports multiple remote
4541 target architectures.
4543 * GDB now supports debugging C and C++ programs which use the
4544 Decimal Floating Point extension. In addition, the PowerPC target
4545 now has a set of pseudo-registers to inspect decimal float values
4546 stored in two consecutive float registers.
4548 * The -break-insert MI command can optionally create pending
4551 * Improved support for debugging Ada
4552 Many improvements to the Ada language support have been made. These
4554 - Better support for Ada2005 interface types
4555 - Improved handling of arrays and slices in general
4556 - Better support for Taft-amendment types
4557 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4559 - Improved command completion in Ada
4562 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4567 set print frame-arguments (all|scalars|none)
4568 show print frame-arguments
4569 The value of this variable can be changed to control which argument
4570 values should be printed by the debugger when displaying a frame.
4575 Transfer files to and from a remote target, and delete remote files.
4582 Transfer files to and from a remote target, and delete remote files.
4584 * New remote packets
4591 Open, close, read, write, and delete files on the remote system.
4594 Attach to an existing process on the remote system, in extended-remote
4598 Run a new process on the remote system, in extended-remote mode.
4600 *** Changes in GDB 6.7
4602 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4603 bfd, libiberty and opcodes, as revealed by static analysis donated by
4604 Coverity, Inc. (http://scan.coverity.com).
4606 * When looking up multiply-defined global symbols, GDB will now prefer the
4607 symbol definition in the current shared library if it was built using the
4608 -Bsymbolic linker option.
4610 * When the Text User Interface (TUI) is not configured, GDB will now
4611 recognize the -tui command-line option and print a message that the TUI
4614 * The GDB remote stub, gdbserver, now has lower overhead for high
4615 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4617 * GDB for MIPS targets now autodetects whether a remote target provides
4618 32-bit or 64-bit register values.
4620 * Support for C++ member pointers has been improved.
4622 * GDB now understands XML target descriptions, which specify the
4623 target's overall architecture. GDB can read a description from
4624 a local file or over the remote serial protocol.
4626 * Vectors of single-byte data use a new integer type which is not
4627 automatically displayed as character or string data.
4629 * The /s format now works with the print command. It displays
4630 arrays of single-byte integers and pointers to single-byte integers
4633 * Target descriptions can now describe target-specific registers,
4634 for architectures which have implemented the support (currently
4635 only ARM, M68K, and MIPS).
4637 * GDB and the GDB remote stub, gdbserver, now support the XScale
4640 * The GDB remote stub, gdbserver, has been updated to support
4641 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4642 has been rewritten to use the standard GDB remote protocol.
4644 * GDB can now step into C++ functions which are called through thunks.
4646 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4648 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4649 layout. It also supports a TextSeg= and DataSeg= response when only
4650 segment base addresses (rather than offsets) are available.
4652 * The /i format now outputs any trailing branch delay slot instructions
4653 immediately following the last instruction within the count specified.
4655 * The GDB remote protocol "T" stop reply packet now supports a
4656 "library" response. Combined with the new "qXfer:libraries:read"
4657 packet, this response allows GDB to debug shared libraries on targets
4658 where the operating system manages the list of loaded libraries (e.g.
4659 Windows and SymbianOS).
4661 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4662 (DLLs) on Windows and Windows CE targets.
4664 * GDB now supports a faster verification that a .debug file matches its binary
4665 according to its build-id signature, if the signature is present.
4671 Enable or disable hardware flow control (RTS/CTS) on the serial port
4672 when debugging using remote targets.
4674 set mem inaccessible-by-default
4675 show mem inaccessible-by-default
4676 If the target supplies a memory map, for instance via the remote
4677 protocol's "qXfer:memory-map:read" packet, setting this variable
4678 prevents GDB from accessing memory outside the memory map. This
4679 is useful for targets with memory mapped registers or which react
4680 badly to accesses of unmapped address space.
4682 set breakpoint auto-hw
4683 show breakpoint auto-hw
4684 If the target supplies a memory map, for instance via the remote
4685 protocol's "qXfer:memory-map:read" packet, setting this variable
4686 lets GDB use hardware breakpoints automatically for memory regions
4687 where it can not use software breakpoints. This covers both the
4688 "break" command and internal breakpoints used for other commands
4689 including "next" and "finish".
4692 catch exception unhandled
4693 Stop the program execution when Ada exceptions are raised.
4696 Stop the program execution when an Ada assertion failed.
4700 Set an alternate system root for target files. This is a more
4701 general version of "set solib-absolute-prefix", which is now
4702 an alias to "set sysroot".
4705 Provide extended SPU facility status information. This set of
4706 commands is available only when debugging the Cell/B.E. SPU
4709 * New native configurations
4711 OpenBSD/sh sh*-*openbsd*
4714 unset tdesc filename
4716 Use the specified local file as an XML target description, and do
4717 not query the target for its built-in description.
4721 OpenBSD/sh sh*-*-openbsd*
4722 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4723 Toshiba Media Processor mep-elf
4725 * New remote packets
4728 Ignore the specified signals; pass them directly to the debugged program
4729 without stopping other threads or reporting them to GDB.
4731 qXfer:features:read:
4732 Read an XML target description from the target, which describes its
4737 Read or write contents of an spufs file on the target system. These
4738 packets are available only on the Cell/B.E. SPU architecture.
4740 qXfer:libraries:read:
4741 Report the loaded shared libraries. Combined with new "T" packet
4742 response, this packet allows GDB to debug shared libraries on
4743 targets where the operating system manages the list of loaded
4744 libraries (e.g. Windows and SymbianOS).
4748 Support for these obsolete configurations has been removed.
4756 i[34567]86-*-lynxos*
4757 i[34567]86-*-netware*
4758 i[34567]86-*-sco3.2v5*
4759 i[34567]86-*-sco3.2v4*
4761 i[34567]86-*-sysv4.2*
4764 i[34567]86-*-unixware2*
4765 i[34567]86-*-unixware*
4774 * Other removed features
4781 Various m68k-only ROM monitors.
4788 Various Renesas ROM monitors and debugging interfaces for SH and
4793 Support for a Macraigor serial interface to on-chip debugging.
4794 GDB does not directly support the newer parallel or USB
4799 A debug information format. The predecessor to DWARF 2 and
4800 DWARF 3, which are still supported.
4802 Support for the HP aCC compiler on HP-UX/PA-RISC
4804 SOM-encapsulated symbolic debugging information, automatic
4805 invocation of pxdb, and the aCC custom C++ ABI. This does not
4806 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4807 with aCC can still be debugged on an assembly level.
4809 MIPS ".pdr" sections
4811 A MIPS-specific format used to describe stack frame layout
4812 in debugging information.
4816 GDB could work with an older version of Guile to debug
4817 the interpreter and Scheme programs running in it.
4819 set mips stack-arg-size
4820 set mips saved-gpreg-size
4822 Use "set mips abi" to control parameter passing for MIPS.
4824 *** Changes in GDB 6.6
4829 Cell Broadband Engine SPU spu-elf
4831 * GDB can now be configured as a cross-debugger targeting native Windows
4832 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4833 running on a Windows system over TCP/IP to debug Windows programs.
4835 * The GDB remote stub, gdbserver, has been updated to support Windows and
4836 Cygwin debugging. Both single-threaded and multi-threaded programs are
4839 * The "set trust-readonly-sections" command works again. This command was
4840 broken in GDB 6.3, 6.4, and 6.5.
4842 * The "load" command now supports writing to flash memory, if the remote
4843 stub provides the required support.
4845 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4846 longer requires symbolic debug information (e.g. DWARF-2).
4851 unset substitute-path
4852 show substitute-path
4853 Manage a list of substitution rules that GDB uses to rewrite the name
4854 of the directories where the sources are located. This can be useful
4855 for instance when the sources were moved to a different location
4856 between compilation and debugging.
4860 Print each CLI command as it is executed. Each command is prefixed with
4861 a number of `+' symbols representing the nesting depth.
4862 The source command now has a `-v' option to enable the same feature.
4866 The ARM Demon monitor support (RDP protocol, "target rdp").
4868 Kernel Object Display, an embedded debugging feature which only worked with
4869 an obsolete version of Cisco IOS.
4871 The 'set download-write-size' and 'show download-write-size' commands.
4873 * New remote packets
4876 Tell a stub about GDB client features, and request remote target features.
4877 The first feature implemented is PacketSize, which allows the target to
4878 specify the size of packets it can handle - to minimize the number of
4879 packets required and improve performance when connected to a remote
4883 Fetch an OS auxilliary vector from the remote stub. This packet is a
4884 more efficient replacement for qPart:auxv:read.
4886 qXfer:memory-map:read:
4887 Fetch a memory map from the remote stub, including information about
4888 RAM, ROM, and flash memory devices.
4893 Erase and program a flash memory device.
4895 * Removed remote packets
4898 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4899 used it, and only gdbserver implemented it.
4901 *** Changes in GDB 6.5
4905 Renesas M32C/M16C m32c-elf
4907 Morpho Technologies ms1 ms1-elf
4911 init-if-undefined Initialize a convenience variable, but
4912 only if it doesn't already have a value.
4914 The following commands are presently only implemented for native GNU/Linux:
4916 checkpoint Save a snapshot of the program state.
4918 restart <n> Return the program state to a
4919 previously saved state.
4921 info checkpoints List currently saved checkpoints.
4923 delete-checkpoint <n> Delete a previously saved checkpoint.
4925 set|show detach-on-fork Tell gdb whether to detach from a newly
4926 forked process, or to keep debugging it.
4928 info forks List forks of the user program that
4929 are available to be debugged.
4931 fork <n> Switch to debugging one of several
4932 forks of the user program that are
4933 available to be debugged.
4935 delete-fork <n> Delete a fork from the list of forks
4936 that are available to be debugged (and
4937 kill the forked process).
4939 detach-fork <n> Delete a fork from the list of forks
4940 that are available to be debugged (and
4941 allow the process to continue).
4945 Morpho Technologies ms2 ms1-elf
4947 * Improved Windows host support
4949 GDB now builds as a cross debugger hosted on i686-mingw32, including
4950 native console support, and remote communications using either
4951 network sockets or serial ports.
4953 * Improved Modula-2 language support
4955 GDB can now print most types in the Modula-2 syntax. This includes:
4956 basic types, set types, record types, enumerated types, range types,
4957 pointer types and ARRAY types. Procedure var parameters are correctly
4958 printed and hexadecimal addresses and character constants are also
4959 written in the Modula-2 syntax. Best results can be obtained by using
4960 GNU Modula-2 together with the -gdwarf-2 command line option.
4964 The ARM rdi-share module.
4966 The Netware NLM debug server.
4968 *** Changes in GDB 6.4
4970 * New native configurations
4972 OpenBSD/arm arm*-*-openbsd*
4973 OpenBSD/mips64 mips64-*-openbsd*
4977 Morpho Technologies ms1 ms1-elf
4979 * New command line options
4981 --batch-silent As for --batch, but totally silent.
4982 --return-child-result The debugger will exist with the same value
4983 the child (debugged) program exited with.
4984 --eval-command COMMAND, -ex COMMAND
4985 Execute a single GDB CLI command. This may be
4986 specified multiple times and in conjunction
4987 with the --command (-x) option.
4989 * Deprecated commands removed
4991 The following commands, that were deprecated in 2000, have been
4995 set|show arm disassembly-flavor set|show arm disassembler
4996 othernames set arm disassembler
4997 set|show remotedebug set|show debug remote
4998 set|show archdebug set|show debug arch
4999 set|show eventdebug set|show debug event
5002 * New BSD user-level threads support
5004 It is now possible to debug programs using the user-level threads
5005 library on OpenBSD and FreeBSD. Currently supported (target)
5008 FreeBSD/amd64 x86_64-*-freebsd*
5009 FreeBSD/i386 i386-*-freebsd*
5010 OpenBSD/i386 i386-*-openbsd*
5012 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5013 are not yet supported.
5015 * New support for Matsushita MN10300 w/sim added
5016 (Work in progress). mn10300-elf.
5018 * REMOVED configurations and files
5020 VxWorks and the XDR protocol *-*-vxworks
5021 Motorola MCORE mcore-*-*
5022 National Semiconductor NS32000 ns32k-*-*
5024 * New "set print array-indexes" command
5026 After turning this setting "on", GDB prints the index of each element
5027 when displaying arrays. The default is "off" to preserve the previous
5030 * VAX floating point support
5032 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5034 * User-defined command support
5036 In addition to using $arg0..$arg9 for argument passing, it is now possible
5037 to use $argc to determine now many arguments have been passed. See the
5038 section on user-defined commands in the user manual for more information.
5040 *** Changes in GDB 6.3:
5042 * New command line option
5044 GDB now accepts -l followed by a number to set the timeout for remote
5047 * GDB works with GCC -feliminate-dwarf2-dups
5049 GDB now supports a more compact representation of DWARF-2 debug
5050 information using DW_FORM_ref_addr references. These are produced
5051 by GCC with the option -feliminate-dwarf2-dups and also by some
5052 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5053 to use -feliminate-dwarf2-dups.
5055 * Internationalization
5057 When supported by the host system, GDB will be built with
5058 internationalization (libintl). The task of marking up the sources is
5059 continued, we're looking forward to our first translation.
5063 Initial support for debugging programs compiled with the GNAT
5064 implementation of the Ada programming language has been integrated
5065 into GDB. In this release, support is limited to expression evaluation.
5067 * New native configurations
5069 GNU/Linux/m32r m32r-*-linux-gnu
5073 GDB's remote protocol now includes support for the 'p' packet. This
5074 packet is used to fetch individual registers from a remote inferior.
5076 * END-OF-LIFE registers[] compatibility module
5078 GDB's internal register infrastructure has been completely rewritten.
5079 The new infrastructure making possible the implementation of key new
5080 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5083 GDB 6.3 will be the last release to include the the registers[]
5084 compatibility module that allowed out-of-date configurations to
5085 continue to work. This change directly impacts the following
5095 powerpc bdm protocol
5097 Unless there is activity to revive these configurations, they will be
5098 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5100 * OBSOLETE configurations and files
5102 Configurations that have been declared obsolete in this release have
5103 been commented out. Unless there is activity to revive these
5104 configurations, the next release of GDB will have their sources
5105 permanently REMOVED.
5114 *** Changes in GDB 6.2.1:
5116 * MIPS `break main; run' gave an heuristic-fence-post warning
5118 When attempting to run even a simple program, a warning about
5119 heuristic-fence-post being hit would be reported. This problem has
5122 * MIPS IRIX 'long double' crashed GDB
5124 When examining a long double variable, GDB would get a segmentation
5125 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5126 IRIX long double values).
5130 A bug in the VAX stack code was causing problems with the "next"
5131 command. This problem has been fixed.
5133 *** Changes in GDB 6.2:
5135 * Fix for ``many threads''
5137 On GNU/Linux systems that use the NPTL threads library, a program
5138 rapidly creating and deleting threads would confuse GDB leading to the
5141 ptrace: No such process.
5142 thread_db_get_info: cannot get thread info: generic error
5144 This problem has been fixed.
5146 * "-async" and "-noasync" options removed.
5148 Support for the broken "-noasync" option has been removed (it caused
5151 * New ``start'' command.
5153 This command runs the program until the begining of the main procedure.
5155 * New BSD Kernel Data Access Library (libkvm) interface
5157 Using ``target kvm'' it is now possible to debug kernel core dumps and
5158 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5159 platforms. Currently supported (native-only) configurations are:
5161 FreeBSD/amd64 x86_64-*-freebsd*
5162 FreeBSD/i386 i?86-*-freebsd*
5163 NetBSD/i386 i?86-*-netbsd*
5164 NetBSD/m68k m68*-*-netbsd*
5165 NetBSD/sparc sparc-*-netbsd*
5166 OpenBSD/amd64 x86_64-*-openbsd*
5167 OpenBSD/i386 i?86-*-openbsd*
5168 OpenBSD/m68k m68*-openbsd*
5169 OpenBSD/sparc sparc-*-openbsd*
5171 * Signal trampoline code overhauled
5173 Many generic problems with GDB's signal handling code have been fixed.
5174 These include: backtraces through non-contiguous stacks; recognition
5175 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5176 call; backtrace through a signal trampoline; step into and out of
5177 signal handlers; and single-stepping in the signal trampoline.
5179 Please note that kernel bugs are a limiting factor here. These
5180 features have been shown to work on an s390 GNU/Linux system that
5181 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5183 * Cygwin support for DWARF 2 added.
5185 * New native configurations
5187 GNU/Linux/hppa hppa*-*-linux*
5188 OpenBSD/hppa hppa*-*-openbsd*
5189 OpenBSD/m68k m68*-*-openbsd*
5190 OpenBSD/m88k m88*-*-openbsd*
5191 OpenBSD/powerpc powerpc-*-openbsd*
5192 NetBSD/vax vax-*-netbsd*
5193 OpenBSD/vax vax-*-openbsd*
5195 * END-OF-LIFE frame compatibility module
5197 GDB's internal frame infrastructure has been completely rewritten.
5198 The new infrastructure making it possible to support key new features
5199 including DWARF 2 Call Frame Information. To aid in the task of
5200 migrating old configurations to this new infrastructure, a
5201 compatibility module, that allowed old configurations to continue to
5202 work, was also included.
5204 GDB 6.2 will be the last release to include this frame compatibility
5205 module. This change directly impacts the following configurations:
5215 Unless there is activity to revive these configurations, they will be
5216 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5218 * REMOVED configurations and files
5220 Sun 3, running SunOS 3 m68*-*-sunos3*
5221 Sun 3, running SunOS 4 m68*-*-sunos4*
5222 Sun 2, running SunOS 3 m68000-*-sunos3*
5223 Sun 2, running SunOS 4 m68000-*-sunos4*
5224 Motorola 680x0 running LynxOS m68*-*-lynxos*
5225 AT&T 3b1/Unix pc m68*-att-*
5226 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5227 decstation mips-dec-* mips-little-*
5228 riscos mips-*-riscos* mips-*-sysv*
5229 sonymips mips-sony-*
5230 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5232 *** Changes in GDB 6.1.1:
5234 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5236 The TUI (Text-mode User Interface) is now built as part of a default
5237 GDB configuration. It is enabled by either selecting the TUI with the
5238 command line option "-i=tui" or by running the separate "gdbtui"
5239 program. For more information on the TUI, see the manual "Debugging
5242 * Pending breakpoint support (also included in GDB 6.1)
5244 Support has been added to allow you to specify breakpoints in shared
5245 libraries that have not yet been loaded. If a breakpoint location
5246 cannot be found, and the "breakpoint pending" option is set to auto,
5247 GDB queries you if you wish to make the breakpoint pending on a future
5248 shared-library load. If and when GDB resolves the breakpoint symbol,
5249 the pending breakpoint is removed as one or more regular breakpoints
5252 Pending breakpoints are very useful for GCJ Java debugging.
5254 * Fixed ISO-C build problems
5256 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5257 non ISO-C code that stopped them being built using a more strict ISO-C
5258 compiler (e.g., IBM's C compiler).
5260 * Fixed build problem on IRIX 5
5262 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5263 wasn't able to compile compile on an IRIX 5 system.
5265 * Added execute permission to gdb/gdbserver/configure
5267 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5268 permission. This bug would cause configure to fail on a number of
5269 systems (Solaris, IRIX). Ref: server/519.
5271 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5273 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5274 has been updated to use constant array sizes.
5276 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5278 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5279 its generated DWARF Call Frame Info. This encoding was causing GDB to
5280 panic, that panic has been fixed. Ref: gdb/1628.
5282 * Fixed a problem when examining parameters in shared library code.
5284 When examining parameters in optimized shared library code generated
5285 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5286 not available''. GDB now correctly displays the variable's value.
5288 *** Changes in GDB 6.1:
5290 * Removed --with-mmalloc
5292 Support for the mmalloc memory manager has been removed, as it
5293 conflicted with the internal gdb byte cache.
5295 * Changes in AMD64 configurations
5297 The AMD64 target now includes the %cs and %ss registers. As a result
5298 the AMD64 remote protocol has changed; this affects the floating-point
5299 and SSE registers. If you rely on those registers for your debugging,
5300 you should upgrade gdbserver on the remote side.
5302 * Revised SPARC target
5304 The SPARC target has been completely revised, incorporating the
5305 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5306 support for LynxOS and SunOS 4 has been dropped. Calling functions
5307 from within GDB on operating systems with a non-executable stack
5308 (Solaris, OpenBSD) now works.
5312 GDB has a new C++ demangler which does a better job on the mangled
5313 names generated by current versions of g++. It also runs faster, so
5314 with this and other changes gdb should now start faster on large C++
5317 * DWARF 2 Location Expressions
5319 GDB support for location expressions has been extended to support function
5320 arguments and frame bases. Older versions of GDB could crash when they
5323 * C++ nested types and namespaces
5325 GDB's support for nested types and namespaces in C++ has been
5326 improved, especially if you use the DWARF 2 debugging format. (This
5327 is the default for recent versions of GCC on most platforms.)
5328 Specifically, if you have a class "Inner" defined within a class or
5329 namespace "Outer", then GDB realizes that the class's name is
5330 "Outer::Inner", not simply "Inner". This should greatly reduce the
5331 frequency of complaints about not finding RTTI symbols. In addition,
5332 if you are stopped at inside of a function defined within a namespace,
5333 GDB modifies its name lookup accordingly.
5335 * New native configurations
5337 NetBSD/amd64 x86_64-*-netbsd*
5338 OpenBSD/amd64 x86_64-*-openbsd*
5339 OpenBSD/alpha alpha*-*-openbsd*
5340 OpenBSD/sparc sparc-*-openbsd*
5341 OpenBSD/sparc64 sparc64-*-openbsd*
5343 * New debugging protocols
5345 M32R with SDI protocol m32r-*-elf*
5347 * "set prompt-escape-char" command deleted.
5349 The command "set prompt-escape-char" has been deleted. This command,
5350 and its very obscure effet on GDB's prompt, was never documented,
5351 tested, nor mentioned in the NEWS file.
5353 * OBSOLETE configurations and files
5355 Configurations that have been declared obsolete in this release have
5356 been commented out. Unless there is activity to revive these
5357 configurations, the next release of GDB will have their sources
5358 permanently REMOVED.
5360 Sun 3, running SunOS 3 m68*-*-sunos3*
5361 Sun 3, running SunOS 4 m68*-*-sunos4*
5362 Sun 2, running SunOS 3 m68000-*-sunos3*
5363 Sun 2, running SunOS 4 m68000-*-sunos4*
5364 Motorola 680x0 running LynxOS m68*-*-lynxos*
5365 AT&T 3b1/Unix pc m68*-att-*
5366 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5367 decstation mips-dec-* mips-little-*
5368 riscos mips-*-riscos* mips-*-sysv*
5369 sonymips mips-sony-*
5370 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5372 * REMOVED configurations and files
5374 SGI Irix-4.x mips-sgi-irix4 or iris4
5375 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5376 Z8000 simulator z8k-zilog-none or z8ksim
5377 Matsushita MN10200 w/simulator mn10200-*-*
5378 H8/500 simulator h8500-hitachi-hms or h8500hms
5379 HP/PA running BSD hppa*-*-bsd*
5380 HP/PA running OSF/1 hppa*-*-osf*
5381 HP/PA Pro target hppa*-*-pro*
5382 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5383 386BSD i[3456]86-*-bsd*
5384 Sequent family i[3456]86-sequent-sysv4*
5385 i[3456]86-sequent-sysv*
5386 i[3456]86-sequent-bsd*
5387 SPARC running LynxOS sparc-*-lynxos*
5388 SPARC running SunOS 4 sparc-*-sunos4*
5389 Tsqware Sparclet sparclet-*-*
5390 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5392 *** Changes in GDB 6.0:
5396 Support for debugging the Objective-C programming language has been
5397 integrated into GDB.
5399 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5401 DWARF 2's Call Frame Information makes available compiler generated
5402 information that more exactly describes the program's run-time stack.
5403 By using this information, GDB is able to provide more robust stack
5406 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5407 have been updated to use a new backtrace mechanism which includes
5408 DWARF 2 CFI support.
5412 GDB's remote protocol has been extended to include support for hosted
5413 file I/O (where the remote target uses GDB's file system). See GDB's
5414 remote protocol documentation for details.
5416 * All targets using the new architecture framework.
5418 All of GDB's targets have been updated to use the new internal
5419 architecture framework. The way is now open for future GDB releases
5420 to include cross-architecture native debugging support (i386 on amd64,
5423 * GNU/Linux's Thread Local Storage (TLS)
5425 GDB now includes support for for the GNU/Linux implementation of
5426 per-thread variables.
5428 * GNU/Linux's Native POSIX Thread Library (NPTL)
5430 GDB's thread code has been updated to work with either the new
5431 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5433 * Separate debug info.
5435 GDB, in conjunction with BINUTILS, now supports a mechanism for
5436 automatically loading debug information from a separate file. Instead
5437 of shipping full debug and non-debug versions of system libraries,
5438 system integrators can now instead ship just the stripped libraries
5439 and optional debug files.
5441 * DWARF 2 Location Expressions
5443 DWARF 2 Location Expressions allow the compiler to more completely
5444 describe the location of variables (even in optimized code) to the
5447 GDB now includes preliminary support for location expressions (support
5448 for DW_OP_piece is still missing).
5452 A number of long standing bugs that caused GDB to die while starting a
5453 Java application have been fixed. GDB's Java support is now
5454 considered "useable".
5456 * GNU/Linux support for fork, vfork, and exec.
5458 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5459 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5462 * GDB supports logging output to a file
5464 There are two new commands, "set logging" and "show logging", which can be
5465 used to capture GDB's output to a file.
5467 * The meaning of "detach" has changed for gdbserver
5469 The "detach" command will now resume the application, as documented. To
5470 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5473 * d10v, m68hc11 `regs' command deprecated
5475 The `info registers' command has been updated so that it displays the
5476 registers using a format identical to the old `regs' command.
5480 A new command, "maint set profile on/off", has been added. This command can
5481 be used to enable or disable profiling while running GDB, to profile a
5482 session or a set of commands. In addition there is a new configure switch,
5483 "--enable-profiling", which will cause GDB to be compiled with profiling
5484 data, for more informative profiling results.
5486 * Default MI syntax changed to "mi2".
5488 The default MI (machine interface) syntax, enabled by the command line
5489 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5490 "mi1", can be enabled by specifying the option "-i=mi1".
5492 Support for the original "mi0" syntax (included in GDB 5.0) has been
5495 Fix for gdb/192: removed extraneous space when displaying frame level.
5496 Fix for gdb/672: update changelist is now output in mi list format.
5497 Fix for gdb/702: a -var-assign that updates the value now shows up
5498 in a subsequent -var-update.
5500 * New native configurations.
5502 FreeBSD/amd64 x86_64-*-freebsd*
5504 * Multi-arched targets.
5506 HP/PA HPUX11 hppa*-*-hpux*
5507 Renesas M32R/D w/simulator m32r-*-elf*
5509 * OBSOLETE configurations and files
5511 Configurations that have been declared obsolete in this release have
5512 been commented out. Unless there is activity to revive these
5513 configurations, the next release of GDB will have their sources
5514 permanently REMOVED.
5516 Z8000 simulator z8k-zilog-none or z8ksim
5517 Matsushita MN10200 w/simulator mn10200-*-*
5518 H8/500 simulator h8500-hitachi-hms or h8500hms
5519 HP/PA running BSD hppa*-*-bsd*
5520 HP/PA running OSF/1 hppa*-*-osf*
5521 HP/PA Pro target hppa*-*-pro*
5522 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5523 Sequent family i[3456]86-sequent-sysv4*
5524 i[3456]86-sequent-sysv*
5525 i[3456]86-sequent-bsd*
5526 Tsqware Sparclet sparclet-*-*
5527 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5529 * REMOVED configurations and files
5532 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5533 IBM AIX PS/2 i[3456]86-*-aix
5534 i386 running Mach 3.0 i[3456]86-*-mach3*
5535 i386 running Mach i[3456]86-*-mach*
5536 i386 running OSF/1 i[3456]86-*osf1mk*
5537 HP/Apollo 68k Family m68*-apollo*-sysv*,
5539 m68*-hp-bsd*, m68*-hp-hpux*
5540 Argonaut Risc Chip (ARC) arc-*-*
5541 Mitsubishi D30V d30v-*-*
5542 Fujitsu FR30 fr30-*-elf*
5543 OS/9000 i[34]86-*-os9k
5544 I960 with MON960 i960-*-coff
5546 * MIPS $fp behavior changed
5548 The convenience variable $fp, for the MIPS, now consistently returns
5549 the address of the current frame's base. Previously, depending on the
5550 context, $fp could refer to either $sp or the current frame's base
5551 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5552 The GNU Source-Level Debugger''.
5554 *** Changes in GDB 5.3:
5556 * GNU/Linux shared library multi-threaded performance improved.
5558 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5559 `/proc', in preference to `ptrace' for memory reads. This may result
5560 in an improvement in the start-up time of multi-threaded, shared
5561 library applications when run under GDB. One GDB user writes: ``loads
5562 shared libs like mad''.
5564 * ``gdbserver'' now supports multi-threaded applications on some targets
5566 Support for debugging multi-threaded applications which use
5567 the GNU/Linux LinuxThreads package has been added for
5568 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5569 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5571 * GDB now supports C/C++ preprocessor macros.
5573 GDB now expands preprocessor macro invocations in C/C++ expressions,
5574 and provides various commands for showing macro definitions and how
5577 The new command `macro expand EXPRESSION' expands any macro
5578 invocations in expression, and shows the result.
5580 The new command `show macro MACRO-NAME' shows the definition of the
5581 macro named MACRO-NAME, and where it was defined.
5583 Most compilers don't include information about macros in the debugging
5584 information by default. In GCC 3.1, for example, you need to compile
5585 your program with the options `-gdwarf-2 -g3'. If the macro
5586 information is present in the executable, GDB will read it.
5588 * Multi-arched targets.
5590 DEC Alpha (partial) alpha*-*-*
5591 DEC VAX (partial) vax-*-*
5593 National Semiconductor NS32000 (partial) ns32k-*-*
5594 Motorola 68000 (partial) m68k-*-*
5595 Motorola MCORE mcore-*-*
5599 Fujitsu FRV architecture added by Red Hat frv*-*-*
5602 * New native configurations
5604 Alpha NetBSD alpha*-*-netbsd*
5605 SH NetBSD sh*-*-netbsdelf*
5606 MIPS NetBSD mips*-*-netbsd*
5607 UltraSPARC NetBSD sparc64-*-netbsd*
5609 * OBSOLETE configurations and files
5611 Configurations that have been declared obsolete in this release have
5612 been commented out. Unless there is activity to revive these
5613 configurations, the next release of GDB will have their sources
5614 permanently REMOVED.
5616 Mitsubishi D30V d30v-*-*
5617 OS/9000 i[34]86-*-os9k
5618 IBM AIX PS/2 i[3456]86-*-aix
5619 Fujitsu FR30 fr30-*-elf*
5620 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5621 Argonaut Risc Chip (ARC) arc-*-*
5622 i386 running Mach 3.0 i[3456]86-*-mach3*
5623 i386 running Mach i[3456]86-*-mach*
5624 i386 running OSF/1 i[3456]86-*osf1mk*
5625 HP/Apollo 68k Family m68*-apollo*-sysv*,
5627 m68*-hp-bsd*, m68*-hp-hpux*
5628 I960 with MON960 i960-*-coff
5630 * OBSOLETE languages
5632 CHILL, a Pascal like language used by telecommunications companies.
5634 * REMOVED configurations and files
5636 AMD 29k family via UDI a29k-amd-udi, udi29k
5637 A29K VxWorks a29k-*-vxworks
5638 AMD 29000 embedded, using EBMON a29k-none-none
5639 AMD 29000 embedded with COFF a29k-none-coff
5640 AMD 29000 embedded with a.out a29k-none-aout
5642 testsuite/gdb.hp/gdb.threads-hp/ directory
5644 * New command "set max-user-call-depth <nnn>"
5646 This command allows the user to limit the call depth of user-defined
5647 commands. The default is 1024.
5649 * Changes in FreeBSD/i386 native debugging.
5651 Support for the "generate-core-file" has been added.
5653 * New commands "dump", "append", and "restore".
5655 These commands allow data to be copied from target memory
5656 to a bfd-format or binary file (dump and append), and back
5657 from a file into memory (restore).
5659 * Improved "next/step" support on multi-processor Alpha Tru64.
5661 The previous single-step mechanism could cause unpredictable problems,
5662 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5663 of a software single-step mechanism prevents this.
5665 *** Changes in GDB 5.2.1:
5673 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5674 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5675 Fix, by Joel Brobecker imported from mainline.
5677 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5678 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5679 Fix, by Fred Fish, imported from mainline.
5681 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5682 Surprisingly enough, it works now.
5683 By Michal Ludvig, imported from mainline.
5685 i386 hardware watchpoint support:
5686 avoid misses on second run for some targets.
5687 By Pierre Muller, imported from mainline.
5689 *** Changes in GDB 5.2:
5691 * New command "set trust-readonly-sections on[off]".
5693 This command is a hint that tells gdb that read-only sections
5694 really are read-only (ie. that their contents will not change).
5695 In this mode, gdb will go to the object file rather than the
5696 target to read memory from read-only sections (such as ".text").
5697 This can be a significant performance improvement on some
5698 (notably embedded) targets.
5700 * New command "generate-core-file" (or "gcore").
5702 This new gdb command allows the user to drop a core file of the child
5703 process state at any time. So far it's been implemented only for
5704 GNU/Linux and Solaris, but should be relatively easily ported to other
5705 hosts. Argument is core file name (defaults to core.<pid>).
5707 * New command line option
5709 GDB now accepts --pid or -p followed by a process id.
5711 * Change in command line behavior -- corefiles vs. process ids.
5713 There is a subtle behavior in the way in which GDB handles
5714 command line arguments. The first non-flag argument is always
5715 a program to debug, but the second non-flag argument may either
5716 be a corefile or a process id. Previously, GDB would attempt to
5717 open the second argument as a corefile, and if that failed, would
5718 issue a superfluous error message and then attempt to attach it as
5719 a process. Now, if the second argument begins with a non-digit,
5720 it will be treated as a corefile. If it begins with a digit,
5721 GDB will attempt to attach it as a process, and if no such process
5722 is found, will then attempt to open it as a corefile.
5724 * Changes in ARM configurations.
5726 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5727 configuration is fully multi-arch.
5729 * New native configurations
5731 ARM NetBSD arm*-*-netbsd*
5732 x86 OpenBSD i[3456]86-*-openbsd*
5733 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5734 Sparc64 running FreeBSD sparc64-*-freebsd*
5738 Sanyo XStormy16 xstormy16-elf
5740 * OBSOLETE configurations and files
5742 Configurations that have been declared obsolete in this release have
5743 been commented out. Unless there is activity to revive these
5744 configurations, the next release of GDB will have their sources
5745 permanently REMOVED.
5747 AMD 29k family via UDI a29k-amd-udi, udi29k
5748 A29K VxWorks a29k-*-vxworks
5749 AMD 29000 embedded, using EBMON a29k-none-none
5750 AMD 29000 embedded with COFF a29k-none-coff
5751 AMD 29000 embedded with a.out a29k-none-aout
5753 testsuite/gdb.hp/gdb.threads-hp/ directory
5755 * REMOVED configurations and files
5757 TI TMS320C80 tic80-*-*
5759 PowerPC Solaris powerpcle-*-solaris*
5760 PowerPC Windows NT powerpcle-*-cygwin32
5761 PowerPC Netware powerpc-*-netware*
5762 Harris/CXUX m88k m88*-harris-cxux*
5763 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5764 ns32k-utek-sysv* ns32k-utek-*
5765 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5766 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5767 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5768 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5769 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5771 * Changes to command line processing
5773 The new `--args' feature can be used to specify command-line arguments
5774 for the inferior from gdb's command line.
5776 * Changes to key bindings
5778 There is a new `operate-and-get-next' function bound to `C-o'.
5780 *** Changes in GDB 5.1.1
5782 Fix compile problem on DJGPP.
5784 Fix a problem with floating-point registers on the i386 being
5787 Fix to stop GDB crashing on .debug_str debug info.
5789 Numerous documentation fixes.
5791 Numerous testsuite fixes.
5793 *** Changes in GDB 5.1:
5795 * New native configurations
5797 Alpha FreeBSD alpha*-*-freebsd*
5798 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5799 MIPS GNU/Linux mips*-*-linux*
5800 MIPS SGI Irix 6.x mips*-sgi-irix6*
5801 ia64 AIX ia64-*-aix*
5802 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5806 Motorola 68HC11 and 68HC12 m68hc11-elf
5808 UltraSparc running GNU/Linux sparc64-*-linux*
5810 * OBSOLETE configurations and files
5812 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5813 Harris/CXUX m88k m88*-harris-cxux*
5814 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5815 ns32k-utek-sysv* ns32k-utek-*
5816 TI TMS320C80 tic80-*-*
5818 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5819 PowerPC Solaris powerpcle-*-solaris*
5820 PowerPC Windows NT powerpcle-*-cygwin32
5821 PowerPC Netware powerpc-*-netware*
5822 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5823 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5824 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5825 Apple Macintosh (MPW) host N/A
5827 stuff.c (Program to stuff files into a specially prepared space in kdb)
5828 kdb-start.c (Main loop for the standalone kernel debugger)
5830 Configurations that have been declared obsolete in this release have
5831 been commented out. Unless there is activity to revive these
5832 configurations, the next release of GDB will have their sources
5833 permanently REMOVED.
5835 * REMOVED configurations and files
5837 Altos 3068 m68*-altos-*
5838 Convex c1-*-*, c2-*-*
5840 ARM RISCix arm-*-* (as host)
5844 * GDB has been converted to ISO C.
5846 GDB's source code has been converted to ISO C. In particular, the
5847 sources are fully protoized, and rely on standard headers being
5852 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5854 * The MI enabled by default.
5856 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5857 revised and enabled by default. Packages which use GDB as a debugging
5858 engine behind a UI or another front end are encouraged to switch to
5859 using the GDB/MI interface, instead of the old annotations interface
5860 which is now deprecated.
5862 * Support for debugging Pascal programs.
5864 GDB now includes support for debugging Pascal programs. The following
5865 main features are supported:
5867 - Pascal-specific data types such as sets;
5869 - automatic recognition of Pascal sources based on file-name
5872 - Pascal-style display of data types, variables, and functions;
5874 - a Pascal expression parser.
5876 However, some important features are not yet supported.
5878 - Pascal string operations are not supported at all;
5880 - there are some problems with boolean types;
5882 - Pascal type hexadecimal constants are not supported
5883 because they conflict with the internal variables format;
5885 - support for Pascal objects and classes is not full yet;
5887 - unlike Pascal, GDB is case-sensitive for symbol names.
5889 * Changes in completion.
5891 Commands such as `shell', `run' and `set args', which pass arguments
5892 to inferior programs, now complete on file names, similar to what
5893 users expect at the shell prompt.
5895 Commands which accept locations, such as `disassemble', `print',
5896 `breakpoint', `until', etc. now complete on filenames as well as
5897 program symbols. Thus, if you type "break foob TAB", and the source
5898 files linked into the programs include `foobar.c', that file name will
5899 be one of the candidates for completion. However, file names are not
5900 considered for completion after you typed a colon that delimits a file
5901 name from a name of a function in that file, as in "break foo.c:bar".
5903 `set demangle-style' completes on available demangling styles.
5905 * New platform-independent commands:
5907 It is now possible to define a post-hook for a command as well as a
5908 hook that runs before the command. For more details, see the
5909 documentation of `hookpost' in the GDB manual.
5911 * Changes in GNU/Linux native debugging.
5913 Support for debugging multi-threaded programs has been completely
5914 revised for all platforms except m68k and sparc. You can now debug as
5915 many threads as your system allows you to have.
5917 Attach/detach is supported for multi-threaded programs.
5919 Support for SSE registers was added for x86. This doesn't work for
5920 multi-threaded programs though.
5922 * Changes in MIPS configurations.
5924 Multi-arch support is enabled for all MIPS configurations.
5926 GDB can now be built as native debugger on SGI Irix 6.x systems for
5927 debugging n32 executables. (Debugging 64-bit executables is not yet
5930 * Unified support for hardware watchpoints in all x86 configurations.
5932 Most (if not all) native x86 configurations support hardware-assisted
5933 breakpoints and watchpoints in a unified manner. This support
5934 implements debug register sharing between watchpoints, which allows to
5935 put a virtually infinite number of watchpoints on the same address,
5936 and also supports watching regions up to 16 bytes with several debug
5939 The new maintenance command `maintenance show-debug-regs' toggles
5940 debugging print-outs in functions that insert, remove, and test
5941 watchpoints and hardware breakpoints.
5943 * Changes in the DJGPP native configuration.
5945 New command ``info dos sysinfo'' displays assorted information about
5946 the CPU, OS, memory, and DPMI server.
5948 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5949 display information about segment descriptors stored in GDT, LDT, and
5952 New commands ``info dos pde'' and ``info dos pte'' display entries
5953 from Page Directory and Page Tables (for now works with CWSDPMI only).
5954 New command ``info dos address-pte'' displays the Page Table entry for
5955 a given linear address.
5957 GDB can now pass command lines longer than 126 characters to the
5958 program being debugged (requires an update to the libdbg.a library
5959 which is part of the DJGPP development kit).
5961 DWARF2 debug info is now supported.
5963 It is now possible to `step' and `next' through calls to `longjmp'.
5965 * Changes in documentation.
5967 All GDB documentation was converted to GFDL, the GNU Free
5968 Documentation License.
5970 Tracepoints-related commands are now fully documented in the GDB
5973 TUI, the Text-mode User Interface, is now documented in the manual.
5975 Tracepoints-related commands are now fully documented in the GDB
5978 The "GDB Internals" manual now has an index. It also includes
5979 documentation of `ui_out' functions, GDB coding standards, x86
5980 hardware watchpoints, and memory region attributes.
5982 * GDB's version number moved to ``version.in''
5984 The Makefile variable VERSION has been replaced by the file
5985 ``version.in''. People creating GDB distributions should update the
5986 contents of this file.
5990 GUD support is now a standard part of the EMACS distribution.
5992 *** Changes in GDB 5.0:
5994 * Improved support for debugging FP programs on x86 targets
5996 Unified and much-improved support for debugging floating-point
5997 programs on all x86 targets. In particular, ``info float'' now
5998 displays the FP registers in the same format on all x86 targets, with
5999 greater level of detail.
6001 * Improvements and bugfixes in hardware-assisted watchpoints
6003 It is now possible to watch array elements, struct members, and
6004 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6005 on x86 targets no longer erroneously trigger when the address is
6008 * Improvements in the native DJGPP version of GDB
6010 The distribution now includes all the scripts and auxiliary files
6011 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6012 machines ``out of the box''.
6014 The DJGPP version can now debug programs that use signals. It is
6015 possible to catch signals that happened in the debuggee, deliver
6016 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6017 would kill the program being debugged.) Programs that hook hardware
6018 interrupts (keyboard, timer, etc.) can also be debugged.
6020 It is now possible to debug DJGPP programs that redirect their
6021 standard handles or switch them to raw (as opposed to cooked) mode, or
6022 even close them. The command ``run < foo > bar'' works as expected,
6023 and ``info terminal'' reports useful information about the debuggee's
6024 terminal, including raw/cooked mode, redirection, etc.
6026 The DJGPP version now uses termios functions for console I/O, which
6027 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6030 DOS-style file names with drive letters are now fully supported by
6033 It is now possible to debug DJGPP programs that switch their working
6034 directory. It is also possible to rerun the debuggee any number of
6035 times without restarting GDB; thus, you can use the same setup,
6036 breakpoints, etc. for many debugging sessions.
6038 * New native configurations
6040 ARM GNU/Linux arm*-*-linux*
6041 PowerPC GNU/Linux powerpc-*-linux*
6045 Motorola MCore mcore-*-*
6046 x86 VxWorks i[3456]86-*-vxworks*
6047 PowerPC VxWorks powerpc-*-vxworks*
6048 TI TMS320C80 tic80-*-*
6050 * OBSOLETE configurations
6052 Altos 3068 m68*-altos-*
6053 Convex c1-*-*, c2-*-*
6055 ARM RISCix arm-*-* (as host)
6058 Configurations that have been declared obsolete will be commented out,
6059 but the code will be left in place. If there is no activity to revive
6060 these configurations before the next release of GDB, the sources will
6061 be permanently REMOVED.
6063 * Gould support removed
6065 Support for the Gould PowerNode and NP1 has been removed.
6067 * New features for SVR4
6069 On SVR4 native platforms (such as Solaris), if you attach to a process
6070 without first loading a symbol file, GDB will now attempt to locate and
6071 load symbols from the running process's executable file.
6073 * Many C++ enhancements
6075 C++ support has been greatly improved. Overload resolution now works properly
6076 in almost all cases. RTTI support is on the way.
6078 * Remote targets can connect to a sub-program
6080 A popen(3) style serial-device has been added. This device starts a
6081 sub-process (such as a stand-alone simulator) and then communicates
6082 with that. The sub-program to run is specified using the syntax
6083 ``|<program> <args>'' vis:
6085 (gdb) set remotedebug 1
6086 (gdb) target extended-remote |mn10300-elf-sim program-args
6088 * MIPS 64 remote protocol
6090 A long standing bug in the mips64 remote protocol where by GDB
6091 expected certain 32 bit registers (ex SR) to be transfered as 32
6092 instead of 64 bits has been fixed.
6094 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6095 added to provide backward compatibility with older versions of GDB.
6097 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6099 The command ``set remotebinarydownload'' command has been replaced by
6100 ``set remote X-packet''. Other commands in ``set remote'' family
6101 include ``set remote P-packet''.
6103 * Breakpoint commands accept ranges.
6105 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6106 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6107 ``tracepoint passcount'' also accepts a range of tracepoints.
6109 * ``apropos'' command added.
6111 The ``apropos'' command searches through command names and
6112 documentation strings, printing out matches, making it much easier to
6113 try to find a command that does what you are looking for.
6117 A new machine oriented interface (MI) has been added to GDB. This
6118 interface is designed for debug environments running GDB as a separate
6119 process. This is part of the long term libGDB project. See the
6120 "GDB/MI" chapter of the GDB manual for further information. It can be
6121 enabled by configuring with:
6123 .../configure --enable-gdbmi
6125 *** Changes in GDB-4.18:
6127 * New native configurations
6129 HP-UX 10.20 hppa*-*-hpux10.20
6130 HP-UX 11.x hppa*-*-hpux11.0*
6131 M68K GNU/Linux m68*-*-linux*
6135 Fujitsu FR30 fr30-*-elf*
6136 Intel StrongARM strongarm-*-*
6137 Mitsubishi D30V d30v-*-*
6139 * OBSOLETE configurations
6141 Gould PowerNode, NP1 np1-*-*, pn-*-*
6143 Configurations that have been declared obsolete will be commented out,
6144 but the code will be left in place. If there is no activity to revive
6145 these configurations before the next release of GDB, the sources will
6146 be permanently REMOVED.
6150 As a compatibility experiment, GDB's source files buildsym.h and
6151 buildsym.c have been converted to pure standard C, no longer
6152 containing any K&R compatibility code. We believe that all systems in
6153 use today either come with a standard C compiler, or have a GCC port
6154 available. If this is not true, please report the affected
6155 configuration to bug-gdb@gnu.org immediately. See the README file for
6156 information about getting a standard C compiler if you don't have one
6161 GDB now uses readline 2.2.
6163 * set extension-language
6165 You can now control the mapping between filename extensions and source
6166 languages by using the `set extension-language' command. For instance,
6167 you can ask GDB to treat .c files as C++ by saying
6168 set extension-language .c c++
6169 The command `info extensions' lists all of the recognized extensions
6170 and their associated languages.
6172 * Setting processor type for PowerPC and RS/6000
6174 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6175 you can use the `set processor' command to specify what variant of the
6176 PowerPC family you are debugging. The command
6180 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6181 following PowerPC and RS6000 variants:
6183 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6184 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6186 403GC IBM PowerPC 403GC
6187 505 Motorola PowerPC 505
6188 860 Motorola PowerPC 860 or 850
6189 601 Motorola PowerPC 601
6190 602 Motorola PowerPC 602
6191 603 Motorola/IBM PowerPC 603 or 603e
6192 604 Motorola PowerPC 604 or 604e
6193 750 Motorola/IBM PowerPC 750 or 750
6195 At the moment, this command just tells GDB what to name the
6196 special-purpose processor registers. Since almost all the affected
6197 registers are inaccessible to user-level programs, this command is
6198 only useful for remote debugging in its present form.
6202 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6203 more extensive support for HP-UX. Added features include shared
6204 library support, kernel threads and hardware watchpoints for 11.00,
6205 support for HP's ANSI C and C++ compilers, and a compatibility mode
6206 for xdb and dbx commands.
6210 HP's donation includes the new concept of catchpoints, which is a
6211 generalization of the old catch command. On HP-UX, it is now possible
6212 to catch exec, fork, and vfork, as well as library loading.
6214 This means that the existing catch command has changed; its first
6215 argument now specifies the type of catch to be set up. See the
6216 output of "help catch" for a list of catchpoint types.
6218 * Debugging across forks
6220 On HP-UX, you can choose which process to debug when a fork() happens
6225 HP has donated a curses-based terminal user interface (TUI). To get
6226 it, build with --enable-tui. Although this can be enabled for any
6227 configuration, at present it only works for native HP debugging.
6229 * GDB remote protocol additions
6231 A new protocol packet 'X' that writes binary data is now available.
6232 Default behavior is to try 'X', then drop back to 'M' if the stub
6233 fails to respond. The settable variable `remotebinarydownload'
6234 allows explicit control over the use of 'X'.
6236 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6237 full 64-bit address. The command
6239 set remoteaddresssize 32
6241 can be used to revert to the old behaviour. For existing remote stubs
6242 the change should not be noticed, as the additional address information
6245 In order to assist in debugging stubs, you may use the maintenance
6246 command `packet' to send any text string to the stub. For instance,
6248 maint packet heythere
6250 sends the packet "$heythere#<checksum>". Note that it is very easy to
6251 disrupt a debugging session by sending the wrong packet at the wrong
6254 The compare-sections command allows you to compare section data on the
6255 target to what is in the executable file without uploading or
6256 downloading, by comparing CRC checksums.
6258 * Tracing can collect general expressions
6260 You may now collect general expressions at tracepoints. This requires
6261 further additions to the target-side stub; see tracepoint.c and
6262 doc/agentexpr.texi for further details.
6264 * mask-address variable for Mips
6266 For Mips targets, you may control the zeroing of the upper 32 bits of
6267 a 64-bit address by entering `set mask-address on'. This is mainly
6268 of interest to users of embedded R4xxx and R5xxx processors.
6270 * Higher serial baud rates
6272 GDB's serial code now allows you to specify baud rates 57600, 115200,
6273 230400, and 460800 baud. (Note that your host system may not be able
6274 to achieve all of these rates.)
6278 The i960 configuration now includes an initial implementation of a
6279 builtin simulator, contributed by Jim Wilson.
6282 *** Changes in GDB-4.17:
6284 * New native configurations
6286 Alpha GNU/Linux alpha*-*-linux*
6287 Unixware 2.x i[3456]86-unixware2*
6288 Irix 6.x mips*-sgi-irix6*
6289 PowerPC GNU/Linux powerpc-*-linux*
6290 PowerPC Solaris powerpcle-*-solaris*
6291 Sparc GNU/Linux sparc-*-linux*
6292 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6296 Argonaut Risc Chip (ARC) arc-*-*
6297 Hitachi H8/300S h8300*-*-*
6298 Matsushita MN10200 w/simulator mn10200-*-*
6299 Matsushita MN10300 w/simulator mn10300-*-*
6300 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6301 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6302 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6303 Mitsubishi D10V w/simulator d10v-*-*
6304 Mitsubishi M32R/D w/simulator m32r-*-elf*
6305 Tsqware Sparclet sparclet-*-*
6306 NEC V850 w/simulator v850-*-*
6308 * New debugging protocols
6310 ARM with RDI protocol arm*-*-*
6311 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6312 DDB and LSI variants of PMON protocol mips*-*-*
6313 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6314 PowerPC with SDS protocol powerpc{,le}-*-eabi
6315 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6319 All configurations can now understand and use the DWARF 2 debugging
6320 format. The choice is automatic, if the symbol file contains DWARF 2
6325 GDB now includes basic Java language support. This support is
6326 only useful with Java compilers that produce native machine code.
6328 * solib-absolute-prefix and solib-search-path
6330 For SunOS and SVR4 shared libraries, you may now set the prefix for
6331 loading absolute shared library symbol files, and the search path for
6332 locating non-absolute shared library symbol files.
6334 * Live range splitting
6336 GDB can now effectively debug code for which GCC has performed live
6337 range splitting as part of its optimization. See gdb/doc/LRS for
6338 more details on the expected format of the stabs information.
6342 GDB's support for the GNU Hurd, including thread debugging, has been
6343 updated to work with current versions of the Hurd.
6347 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6348 instruction set. ARM GDB automatically detects when Thumb
6349 instructions are in use, and adjusts disassembly and backtracing
6354 GDB's MIPS target configurations now handle the MIP16 16-bit
6359 GDB now includes support for overlays; if an executable has been
6360 linked such that multiple sections are based at the same address, GDB
6361 will decide which section to use for symbolic info. You can choose to
6362 control the decision manually, using overlay commands, or implement
6363 additional target-side support and use "overlay load-target" to bring
6364 in the overlay mapping. Do "help overlay" for more detail.
6368 The command "info symbol <address>" displays information about
6369 the symbol at the specified address.
6373 The standard remote protocol now includes an extension that allows
6374 asynchronous collection and display of trace data. This requires
6375 extensive support in the target-side debugging stub. Tracing mode
6376 includes a new interaction mode in GDB and new commands: see the
6377 file tracepoint.c for more details.
6381 Configurations for embedded MIPS now include a simulator contributed
6382 by Cygnus Solutions. The simulator supports the instruction sets
6383 of most MIPS variants.
6387 Sparc configurations may now include the ERC32 simulator contributed
6388 by the European Space Agency. The simulator is not built into
6389 Sparc targets by default; configure with --enable-sim to include it.
6393 For target configurations that may include multiple variants of a
6394 basic architecture (such as MIPS and SH), you may now set the
6395 architecture explicitly. "set arch" sets, "info arch" lists
6396 the possible architectures.
6398 *** Changes in GDB-4.16:
6400 * New native configurations
6402 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6403 M68K NetBSD m68k-*-netbsd*
6404 PowerPC AIX 4.x powerpc-*-aix*
6405 PowerPC MacOS powerpc-*-macos*
6406 PowerPC Windows NT powerpcle-*-cygwin32
6407 RS/6000 AIX 4.x rs6000-*-aix4*
6411 ARM with RDP protocol arm-*-*
6412 I960 with MON960 i960-*-coff
6413 MIPS VxWorks mips*-*-vxworks*
6414 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6415 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6417 Matra Sparclet sparclet-*-*
6421 The powerpc-eabi configuration now includes the PSIM simulator,
6422 contributed by Andrew Cagney, with assistance from Mike Meissner.
6423 PSIM is a very elaborate model of the PowerPC, including not only
6424 basic instruction set execution, but also details of execution unit
6425 performance and I/O hardware. See sim/ppc/README for more details.
6429 GDB now works with Solaris 2.5.
6431 * Windows 95/NT native
6433 GDB will now work as a native debugger on Windows 95 and Windows NT.
6434 To build it from source, you must use the "gnu-win32" environment,
6435 which uses a DLL to emulate enough of Unix to run the GNU tools.
6436 Further information, binaries, and sources are available at
6437 ftp.cygnus.com, under pub/gnu-win32.
6439 * dont-repeat command
6441 If a user-defined command includes the command `dont-repeat', then the
6442 command will not be repeated if the user just types return. This is
6443 useful if the command is time-consuming to run, so that accidental
6444 extra keystrokes don't run the same command many times.
6446 * Send break instead of ^C
6448 The standard remote protocol now includes an option to send a break
6449 rather than a ^C to the target in order to interrupt it. By default,
6450 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6452 * Remote protocol timeout
6454 The standard remote protocol includes a new variable `remotetimeout'
6455 that allows you to set the number of seconds before GDB gives up trying
6456 to read from the target. The default value is 2.
6458 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6460 By default GDB will automatically keep track of objects as they are
6461 loaded and unloaded by the dynamic linker. By using the command `set
6462 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6463 when shared library events occur, thus allowing you to set breakpoints
6464 in shared libraries which are explicitly loaded by the inferior.
6466 Note this feature does not work on hpux8. On hpux9 you must link
6467 /usr/lib/end.o into your program. This feature should work
6468 automatically on hpux10.
6470 * Irix 5.x hardware watchpoint support
6472 Irix 5 configurations now support the use of hardware watchpoints.
6474 * Mips protocol "SYN garbage limit"
6476 When debugging a Mips target using the `target mips' protocol, you
6477 may set the number of characters that GDB will ignore by setting
6478 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6479 every character. The default value is 1050.
6481 * Recording and replaying remote debug sessions
6483 If you set `remotelogfile' to the name of a file, gdb will write to it
6484 a recording of a remote debug session. This recording may then be
6485 replayed back to gdb using "gdbreplay". See gdbserver/README for
6486 details. This is useful when you have a problem with GDB while doing
6487 remote debugging; you can make a recording of the session and send it
6488 to someone else, who can then recreate the problem.
6490 * Speedups for remote debugging
6492 GDB includes speedups for downloading and stepping MIPS systems using
6493 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6494 and more efficient S-record downloading.
6496 * Memory use reductions and statistics collection
6498 GDB now uses less memory and reports statistics about memory usage.
6499 Try the `maint print statistics' command, for example.
6501 *** Changes in GDB-4.15:
6503 * Psymtabs for XCOFF
6505 The symbol reader for AIX GDB now uses partial symbol tables. This
6506 can greatly improve startup time, especially for large executables.
6508 * Remote targets use caching
6510 Remote targets now use a data cache to speed up communication with the
6511 remote side. The data cache could lead to incorrect results because
6512 it doesn't know about volatile variables, thus making it impossible to
6513 debug targets which use memory mapped I/O devices. `set remotecache
6514 off' turns the the data cache off.
6516 * Remote targets may have threads
6518 The standard remote protocol now includes support for multiple threads
6519 in the target system, using new protocol commands 'H' and 'T'. See
6520 gdb/remote.c for details.
6524 If GDB is configured with `--enable-netrom', then it will include
6525 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6526 acts as though it is a bank of ROM on the target board, but you can
6527 write into it over the network. GDB's support consists only of
6528 support for fast loading into the emulated ROM; to debug, you must use
6529 another protocol, such as standard remote protocol. The usual
6530 sequence is something like
6532 target nrom <netrom-hostname>
6534 target remote <netrom-hostname>:1235
6538 GDB now includes support for the Apple Macintosh, as a host only. It
6539 may be run as either an MPW tool or as a standalone application, and
6540 it can debug through the serial port. All the usual GDB commands are
6541 available, but to the target command, you must supply "serial" as the
6542 device type instead of "/dev/ttyXX". See mpw-README in the main
6543 directory for more information on how to build. The MPW configuration
6544 scripts */mpw-config.in support only a few targets, and only the
6545 mips-idt-ecoff target has been tested.
6549 GDB configuration now uses autoconf. This is not user-visible,
6550 but does simplify configuration and building.
6554 GDB now supports hpux10.
6556 *** Changes in GDB-4.14:
6558 * New native configurations
6560 x86 FreeBSD i[345]86-*-freebsd
6561 x86 NetBSD i[345]86-*-netbsd
6562 NS32k NetBSD ns32k-*-netbsd
6563 Sparc NetBSD sparc-*-netbsd
6567 A29K VxWorks a29k-*-vxworks
6568 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6569 CPU32 EST-300 emulator m68*-*-est*
6570 PowerPC ELF powerpc-*-elf
6573 * Alpha OSF/1 support for procfs
6575 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6576 possible to attach to running processes. As the mounting of the /proc
6577 filesystem is optional on the Alpha, GDB automatically determines
6578 the availability of /proc during startup. This can lead to problems
6579 if /proc is unmounted after GDB has been started.
6581 * Arguments to user-defined commands
6583 User commands may accept up to 10 arguments separated by whitespace.
6584 Arguments are accessed within the user command via $arg0..$arg9. A
6587 print $arg0 + $arg1 + $arg2
6589 To execute the command use:
6592 Defines the command "adder" which prints the sum of its three arguments.
6593 Note the arguments are text substitutions, so they may reference variables,
6594 use complex expressions, or even perform inferior function calls.
6596 * New `if' and `while' commands
6598 This makes it possible to write more sophisticated user-defined
6599 commands. Both commands take a single argument, which is the
6600 expression to evaluate, and must be followed by the commands to
6601 execute, one per line, if the expression is nonzero, the list being
6602 terminated by the word `end'. The `if' command list may include an
6603 `else' word, which causes the following commands to be executed only
6604 if the expression is zero.
6606 * Fortran source language mode
6608 GDB now includes partial support for Fortran 77. It will recognize
6609 Fortran programs and can evaluate a subset of Fortran expressions, but
6610 variables and functions may not be handled correctly. GDB will work
6611 with G77, but does not yet know much about symbols emitted by other
6614 * Better HPUX support
6616 Most debugging facilities now work on dynamic executables for HPPAs
6617 running hpux9 or later. You can attach to running dynamically linked
6618 processes, but by default the dynamic libraries will be read-only, so
6619 for instance you won't be able to put breakpoints in them. To change
6620 that behavior do the following before running the program:
6626 This will cause the libraries to be mapped private and read-write.
6627 To revert to the normal behavior, do this:
6633 You cannot set breakpoints or examine data in the library until after
6634 the library is loaded if the function/data symbols do not have
6637 GDB can now also read debug symbols produced by the HP C compiler on
6638 HPPAs (sorry, no C++, Fortran or 68k support).
6640 * Target byte order now dynamically selectable
6642 You can choose which byte order to use with a target system, via the
6643 commands "set endian big" and "set endian little", and you can see the
6644 current setting by using "show endian". You can also give the command
6645 "set endian auto", in which case GDB will use the byte order
6646 associated with the executable. Currently, only embedded MIPS
6647 configurations support dynamic selection of target byte order.
6649 * New DOS host serial code
6651 This version uses DPMI interrupts to handle buffered I/O, so you
6652 no longer need to run asynctsr when debugging boards connected to
6655 *** Changes in GDB-4.13:
6657 * New "complete" command
6659 This lists all the possible completions for the rest of the line, if it
6660 were to be given as a command itself. This is intended for use by emacs.
6662 * Trailing space optional in prompt
6664 "set prompt" no longer adds a space for you after the prompt you set. This
6665 allows you to set a prompt which ends in a space or one that does not.
6667 * Breakpoint hit counts
6669 "info break" now displays a count of the number of times the breakpoint
6670 has been hit. This is especially useful in conjunction with "ignore"; you
6671 can ignore a large number of breakpoint hits, look at the breakpoint info
6672 to see how many times the breakpoint was hit, then run again, ignoring one
6673 less than that number, and this will get you quickly to the last hit of
6676 * Ability to stop printing at NULL character
6678 "set print null-stop" will cause GDB to stop printing the characters of
6679 an array when the first NULL is encountered. This is useful when large
6680 arrays actually contain only short strings.
6682 * Shared library breakpoints
6684 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6685 breakpoints in shared libraries before the executable is run.
6687 * Hardware watchpoints
6689 There is a new hardware breakpoint for the watch command for sparclite
6690 targets. See gdb/sparclite/hw_breakpoint.note.
6692 Hardware watchpoints are also now supported under GNU/Linux.
6696 Annotations have been added. These are for use with graphical interfaces,
6697 and are still experimental. Currently only gdba.el uses these.
6699 * Improved Irix 5 support
6701 GDB now works properly with Irix 5.2.
6703 * Improved HPPA support
6705 GDB now works properly with the latest GCC and GAS.
6707 * New native configurations
6709 Sequent PTX4 i[34]86-sequent-ptx4
6710 HPPA running OSF/1 hppa*-*-osf*
6711 Atari TT running SVR4 m68*-*-sysv4*
6712 RS/6000 LynxOS rs6000-*-lynxos*
6716 OS/9000 i[34]86-*-os9k
6717 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6720 * Hitachi SH7000 and E7000-PC ICE support
6722 There is now support for communicating with the Hitachi E7000-PC ICE.
6723 This is available automatically when GDB is configured for the SH.
6727 As usual, a variety of small fixes and improvements, both generic
6728 and configuration-specific. See the ChangeLog for more detail.
6730 *** Changes in GDB-4.12:
6732 * Irix 5 is now supported
6736 GDB-4.12 on the HPPA has a number of changes which make it unable
6737 to debug the output from the currently released versions of GCC and
6738 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6739 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6740 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6743 *** Changes in GDB-4.11:
6745 * User visible changes:
6749 The "set remotedebug" option is now consistent between the mips remote
6750 target, remote targets using the gdb-specific protocol, UDI (AMD's
6751 debug protocol for the 29k) and the 88k bug monitor. It is now an
6752 integer specifying a debug level (normally 0 or 1, but 2 means more
6753 debugging info for the mips target).
6755 * DEC Alpha native support
6757 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6758 debug info, but GDB works fairly well with the DEC compiler and should
6759 work with a future GCC release. See the README file for a few
6760 Alpha-specific notes.
6762 * Preliminary thread implementation
6764 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6766 * LynxOS native and target support for 386
6768 This release has been hosted on LynxOS 2.2, and also can be configured
6769 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6772 * Improvements in C++ mangling/demangling.
6774 This release has much better g++ debugging, specifically in name
6775 mangling/demangling, virtual function calls, print virtual table,
6776 call methods, ...etc.
6778 *** Changes in GDB-4.10:
6780 * User visible changes:
6782 Remote debugging using the GDB-specific (`target remote') protocol now
6783 supports the `load' command. This is only useful if you have some
6784 other way of getting the stub to the target system, and you can put it
6785 somewhere in memory where it won't get clobbered by the download.
6787 Filename completion now works.
6789 When run under emacs mode, the "info line" command now causes the
6790 arrow to point to the line specified. Also, "info line" prints
6791 addresses in symbolic form (as well as hex).
6793 All vxworks based targets now support a user settable option, called
6794 vxworks-timeout. This option represents the number of seconds gdb
6795 should wait for responses to rpc's. You might want to use this if
6796 your vxworks target is, perhaps, a slow software simulator or happens
6797 to be on the far side of a thin network line.
6801 This release contains support for using a DEC alpha as a GDB host for
6802 cross debugging. Native alpha debugging is not supported yet.
6805 *** Changes in GDB-4.9:
6809 This is the first GDB release which is accompanied by a matching testsuite.
6810 The testsuite requires installation of dejagnu, which should be available
6811 via ftp from most sites that carry GNU software.
6815 'Cfront' style demangling has had its name changed to 'ARM' style, to
6816 emphasize that it was written from the specifications in the C++ Annotated
6817 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6818 disclaimers, it still generated too much confusion with users attempting to
6819 use gdb with AT&T cfront.
6823 GDB now uses a standard remote interface to a simulator library.
6824 So far, the library contains simulators for the Zilog Z8001/2, the
6825 Hitachi H8/300, H8/500 and Super-H.
6827 * New targets supported
6829 H8/300 simulator h8300-hitachi-hms or h8300hms
6830 H8/500 simulator h8500-hitachi-hms or h8500hms
6831 SH simulator sh-hitachi-hms or sh
6832 Z8000 simulator z8k-zilog-none or z8ksim
6833 IDT MIPS board over serial line mips-idt-ecoff
6835 Cross-debugging to GO32 targets is supported. It requires a custom
6836 version of the i386-stub.c module which is integrated with the
6837 GO32 memory extender.
6839 * New remote protocols
6841 MIPS remote debugging protocol.
6843 * New source languages supported
6845 This version includes preliminary support for Chill, a Pascal like language
6846 used by telecommunications companies. Chill support is also being integrated
6847 into the GNU compiler, but we don't know when it will be publically available.
6850 *** Changes in GDB-4.8:
6852 * HP Precision Architecture supported
6854 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6855 version of this support was available as a set of patches from the
6856 University of Utah. GDB does not support debugging of programs
6857 compiled with the HP compiler, because HP will not document their file
6858 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6859 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6861 Many problems in the preliminary version have been fixed.
6863 * Faster and better demangling
6865 We have improved template demangling and fixed numerous bugs in the GNU style
6866 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6867 character types (wchar_t) are now supported. Demangling of each symbol is now
6868 only done once, and is cached when the symbol table for a file is read in.
6869 This results in a small increase in memory usage for C programs, a moderate
6870 increase in memory usage for C++ programs, and a fantastic speedup in
6873 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6874 from the specifications in the Annotated Reference Manual, which AT&T's
6875 compiler does not actually implement.
6877 * G++ multiple inheritance compiler problem
6879 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6880 inheritance lattices was reworked to properly discover ambiguities. We
6881 recently found an example which causes this new algorithm to fail in a
6882 very subtle way, producing bad debug information for those classes.
6883 The file 'gcc.patch' (in this directory) can be applied to gcc to
6884 circumvent the problem. A future GCC release will contain a complete
6887 The previous G++ debug info problem (mentioned below for the gdb-4.7
6888 release) is fixed in gcc version 2.3.2.
6890 * Improved configure script
6892 The `configure' script will now attempt to guess your system type if
6893 you don't supply a host system type. The old scheme of supplying a
6894 host system triplet is preferable over using this. All the magic is
6895 done in the new `config.guess' script. Examine it for details.
6897 We have also brought our configure script much more in line with the FSF's
6898 version. It now supports the --with-xxx options. In particular,
6899 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6900 The resulting GDB will not be able to read arbitrary object file formats --
6901 only the format ``expected'' to be used on the configured target system.
6902 We hope to make this the default in a future release.
6904 * Documentation improvements
6906 There's new internal documentation on how to modify GDB, and how to
6907 produce clean changes to the code. We implore people to read it
6908 before submitting changes.
6910 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6911 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6912 `info' files are also provided. To build `info' files from scratch,
6913 you will need the latest `makeinfo' release, which will be available in
6914 a future texinfo-X.Y release.
6916 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6917 We're not sure exactly which versions have this problem, but it has
6918 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6919 or better. If that isn't possible, there is a patch in
6920 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6921 around this problem.
6925 GDB now supports array constants that can be used in expressions typed in by
6926 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6927 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6930 The new directory `gdb/sparclite' contains a program that demonstrates
6931 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6933 * New native hosts supported
6935 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6936 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6938 * New targets supported
6940 AMD 29k family via UDI a29k-amd-udi or udi29k
6942 * New file formats supported
6944 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6945 HPUX core files, and SCO 3.2v2 core files.
6949 Attaching to processes now works again; thanks for the many bug reports.
6951 We have also stomped on a bunch of core dumps caused by
6952 printf_filtered("%s") problems.
6954 We eliminated a copyright problem on the rpc and ptrace header files
6955 for VxWorks, which was discovered at the last minute during the 4.7
6956 release. You should now be able to build a VxWorks GDB.
6958 You can now interrupt gdb while an attached process is running. This
6959 will cause the attached process to stop, and give control back to GDB.
6961 We fixed problems caused by using too many file descriptors
6962 for reading symbols from object files and libraries. This was
6963 especially a problem for programs that used many (~100) shared
6966 The `step' command now only enters a subroutine if there is line number
6967 information for the subroutine. Otherwise it acts like the `next'
6968 command. Previously, `step' would enter subroutines if there was
6969 any debugging information about the routine. This avoids problems
6970 when using `cc -g1' on MIPS machines.
6972 * Internal improvements
6974 GDB's internal interfaces have been improved to make it easier to support
6975 debugging of multiple languages in the future.
6977 GDB now uses a common structure for symbol information internally.
6978 Minimal symbols (derived from linkage symbols in object files), partial
6979 symbols (from a quick scan of debug information), and full symbols
6980 contain a common subset of information, making it easier to write
6981 shared code that handles any of them.
6983 * New command line options
6985 We now accept --silent as an alias for --quiet.
6989 The memory-mapped-malloc library is now licensed under the GNU Library
6990 General Public License.
6992 *** Changes in GDB-4.7:
6994 * Host/native/target split
6996 GDB has had some major internal surgery to untangle the support for
6997 hosts and remote targets. Now, when you configure GDB for a remote
6998 target, it will no longer load in all of the support for debugging
6999 local programs on the host. When fully completed and tested, this will
7000 ensure that arbitrary host/target combinations are possible.
7002 The primary conceptual shift is to separate the non-portable code in
7003 GDB into three categories. Host specific code is required any time GDB
7004 is compiled on that host, regardless of the target. Target specific
7005 code relates to the peculiarities of the target, but can be compiled on
7006 any host. Native specific code is everything else: it can only be
7007 built when the host and target are the same system. Child process
7008 handling and core file support are two common `native' examples.
7010 GDB's use of /proc for controlling Unix child processes is now cleaner.
7011 It has been split out into a single module under the `target_ops' vector,
7012 plus two native-dependent functions for each system that uses /proc.
7014 * New hosts supported
7016 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7017 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7018 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7020 * New targets supported
7022 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7023 68030 and CPU32 m68030-*-*, m68332-*-*
7025 * New native hosts supported
7027 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7028 (386bsd is not well tested yet)
7029 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7031 * New file formats supported
7033 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7034 supports reading of `a.out.adobe' object files, which are an a.out
7035 format extended with minimal information about multiple sections.
7039 `show copying' is the same as the old `info copying'.
7040 `show warranty' is the same as `info warrantee'.
7041 These were renamed for consistency. The old commands continue to work.
7043 `info handle' is a new alias for `info signals'.
7045 You can now define pre-command hooks, which attach arbitrary command
7046 scripts to any command. The commands in the hook will be executed
7047 prior to the user's command. You can also create a hook which will be
7048 executed whenever the program stops. See gdb.texinfo.
7052 We now deal with Cfront style name mangling, and can even extract type
7053 info from mangled symbols. GDB can automatically figure out which
7054 symbol mangling style your C++ compiler uses.
7056 Calling of methods and virtual functions has been improved as well.
7060 The crash that occured when debugging Sun Ansi-C compiled binaries is
7061 fixed. This was due to mishandling of the extra N_SO stabs output
7064 We also finally got Ultrix 4.2 running in house, and fixed core file
7065 support, with help from a dozen people on the net.
7067 John M. Farrell discovered that the reason that single-stepping was so
7068 slow on all of the Mips based platforms (primarily SGI and DEC) was
7069 that we were trying to demangle and lookup a symbol used for internal
7070 purposes on every instruction that was being stepped through. Changing
7071 the name of that symbol so that it couldn't be mistaken for a C++
7072 mangled symbol sped things up a great deal.
7074 Rich Pixley sped up symbol lookups in general by getting much smarter
7075 about when C++ symbol mangling is necessary. This should make symbol
7076 completion (TAB on the command line) much faster. It's not as fast as
7077 we'd like, but it's significantly faster than gdb-4.6.
7081 A new user controllable variable 'call_scratch_address' can
7082 specify the location of a scratch area to be used when GDB
7083 calls a function in the target. This is necessary because the
7084 usual method of putting the scratch area on the stack does not work
7085 in systems that have separate instruction and data spaces.
7087 We integrated changes to support the 29k UDI (Universal Debugger
7088 Interface), but discovered at the last minute that we didn't have all
7089 of the appropriate copyright paperwork. We are working with AMD to
7090 resolve this, and hope to have it available soon.
7094 We have sped up the remote serial line protocol, especially for targets
7095 with lots of registers. It now supports a new `expedited status' ('T')
7096 message which can be used in place of the existing 'S' status message.
7097 This allows the remote stub to send only the registers that GDB
7098 needs to make a quick decision about single-stepping or conditional
7099 breakpoints, eliminating the need to fetch the entire register set for
7100 each instruction being stepped through.
7102 The GDB remote serial protocol now implements a write-through cache for
7103 registers, only re-reading the registers if the target has run.
7105 There is also a new remote serial stub for SPARC processors. You can
7106 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7107 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7108 processor with a serial port.
7112 Configure.in files have become much easier to read and modify. A new
7113 `table driven' format makes it more obvious what configurations are
7114 supported, and what files each one uses.
7118 There is a new opcodes library which will eventually contain all of the
7119 disassembly routines and opcode tables. At present, it only contains
7120 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7121 disassembler (binutils/objdump) to share these routines.
7123 The libiberty library is now copylefted under the GNU Library General
7124 Public License. This allows more liberal use, and was done so libg++
7125 can use it. This makes no difference to GDB, since the Library License
7126 grants all the rights from the General Public License.
7130 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7131 reference to the stabs symbol info used by the debugger. It is (as far
7132 as we know) the only published document on this fascinating topic. We
7133 encourage you to read it, compare it to the stabs information on your
7134 system, and send improvements on the document in general (to
7135 bug-gdb@prep.ai.mit.edu).
7137 And, of course, many bugs have been fixed.
7140 *** Changes in GDB-4.6:
7142 * Better support for C++ function names
7144 GDB now accepts as input the "demangled form" of C++ overloaded function
7145 names and member function names, and can do command completion on such names
7146 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7147 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7148 Make use of command completion, it is your friend.
7150 GDB also now accepts a variety of C++ mangled symbol formats. They are
7151 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7152 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7153 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7154 for the list of formats.
7156 * G++ symbol mangling problem
7158 Recent versions of gcc have a bug in how they emit debugging information for
7159 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7160 directory) can be applied to gcc to fix the problem. Alternatively, if you
7161 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7162 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7163 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7166 * New 'maintenance' command
7168 All of the commands related to hacking GDB internals have been moved out of
7169 the main command set, and now live behind the 'maintenance' command. This
7170 can also be abbreviated as 'mt'. The following changes were made:
7172 dump-me -> maintenance dump-me
7173 info all-breakpoints -> maintenance info breakpoints
7174 printmsyms -> maintenance print msyms
7175 printobjfiles -> maintenance print objfiles
7176 printpsyms -> maintenance print psymbols
7177 printsyms -> maintenance print symbols
7179 The following commands are new:
7181 maintenance demangle Call internal GDB demangler routine to
7182 demangle a C++ link name and prints the result.
7183 maintenance print type Print a type chain for a given symbol
7185 * Change to .gdbinit file processing
7187 We now read the $HOME/.gdbinit file before processing the argv arguments
7188 (e.g. reading symbol files or core files). This allows global parameters to
7189 be set, which will apply during the symbol reading. The ./.gdbinit is still
7190 read after argv processing.
7192 * New hosts supported
7194 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7196 GNU/Linux support i386-unknown-linux or linux
7198 We are also including code to support the HP/PA running BSD and HPUX. This
7199 is almost guaranteed not to work, as we didn't have time to test or build it
7200 for this release. We are including it so that the more adventurous (or
7201 masochistic) of you can play with it. We also had major problems with the
7202 fact that the compiler that we got from HP doesn't support the -g option.
7205 * New targets supported
7207 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7209 * More smarts about finding #include files
7211 GDB now remembers the compilation directory for all include files, and for
7212 all files from which C is generated (like yacc and lex sources). This
7213 greatly improves GDB's ability to find yacc/lex sources, and include files,
7214 especially if you are debugging your program from a directory different from
7215 the one that contains your sources.
7217 We also fixed a bug which caused difficulty with listing and setting
7218 breakpoints in include files which contain C code. (In the past, you had to
7219 try twice in order to list an include file that you hadn't looked at before.)
7221 * Interesting infernals change
7223 GDB now deals with arbitrary numbers of sections, where the symbols for each
7224 section must be relocated relative to that section's landing place in the
7225 target's address space. This work was needed to support ELF with embedded
7226 stabs used by Solaris-2.0.
7228 * Bug fixes (of course!)
7230 There have been loads of fixes for the following things:
7231 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7232 i960, stabs, DOS(GO32), procfs, etc...
7234 See the ChangeLog for details.
7236 *** Changes in GDB-4.5:
7238 * New machines supported (host and target)
7240 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7242 SGI Irix-4.x mips-sgi-irix4 or iris4
7244 * New malloc package
7246 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7247 Mmalloc is capable of handling mutiple heaps of memory. It is also
7248 capable of saving a heap to a file, and then mapping it back in later.
7249 This can be used to greatly speedup the startup of GDB by using a
7250 pre-parsed symbol table which lives in a mmalloc managed heap. For
7251 more details, please read mmalloc/mmalloc.texi.
7255 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7256 'help info proc' for details.
7258 * MIPS ecoff symbol table format
7260 The code that reads MIPS symbol table format is now supported on all hosts.
7261 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7264 * File name changes for MS-DOS
7266 Many files in the config directories have been renamed to make it easier to
7267 support GDB on MS-DOSe systems (which have very restrictive file name
7268 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7269 environment) is close to working but has some remaining problems. Note
7270 that debugging of DOS programs is not supported, due to limitations
7271 in the ``operating system'', but it can be used to host cross-debugging.
7273 * Cross byte order fixes
7275 Many fixes have been made to support cross debugging of Sparc and MIPS
7276 targets from hosts whose byte order differs.
7278 * New -mapped and -readnow options
7280 If memory-mapped files are available on your system through the 'mmap'
7281 system call, you can use the -mapped option on the `file' or
7282 `symbol-file' commands to cause GDB to write the symbols from your
7283 program into a reusable file. If the program you are debugging is
7284 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7285 Future GDB debugging sessions will notice the presence of this file,
7286 and will quickly map in symbol information from it, rather than reading
7287 the symbol table from the executable program. Using the '-mapped'
7288 option in a GDB `file' or `symbol-file' command has the same effect as
7289 starting GDB with the '-mapped' command-line option.
7291 You can cause GDB to read the entire symbol table immediately by using
7292 the '-readnow' option with any of the commands that load symbol table
7293 information (or on the GDB command line). This makes the command
7294 slower, but makes future operations faster.
7296 The -mapped and -readnow options are typically combined in order to
7297 build a `fred.syms' file that contains complete symbol information.
7298 A simple GDB invocation to do nothing but build a `.syms' file for future
7301 gdb -batch -nx -mapped -readnow programname
7303 The `.syms' file is specific to the host machine on which GDB is run.
7304 It holds an exact image of GDB's internal symbol table. It cannot be
7305 shared across multiple host platforms.
7307 * longjmp() handling
7309 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7310 siglongjmp() without losing control. This feature has not yet been ported to
7311 all systems. It currently works on many 386 platforms, all MIPS-based
7312 platforms (SGI, DECstation, etc), and Sun3/4.
7316 Preliminary work has been put in to support the new Solaris OS from Sun. At
7317 this time, it can control and debug processes, but it is not capable of
7322 As always, many many bug fixes. The major areas were with g++, and mipsread.
7323 People using the MIPS-based platforms should experience fewer mysterious
7324 crashes and trashed symbol tables.
7326 *** Changes in GDB-4.4:
7328 * New machines supported (host and target)
7330 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7332 BSD Reno on Vax vax-dec-bsd
7333 Ultrix on Vax vax-dec-ultrix
7335 * New machines supported (target)
7337 AMD 29000 embedded, using EBMON a29k-none-none
7341 GDB continues to improve its handling of C++. `References' work better.
7342 The demangler has also been improved, and now deals with symbols mangled as
7343 per the Annotated C++ Reference Guide.
7345 GDB also now handles `stabs' symbol information embedded in MIPS
7346 `ecoff' symbol tables. Since the ecoff format was not easily
7347 extensible to handle new languages such as C++, this appeared to be a
7348 good way to put C++ debugging info into MIPS binaries. This option
7349 will be supported in the GNU C compiler, version 2, when it is
7352 * New features for SVR4
7354 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7355 shared libraries. Debugging dynamically linked programs should present
7356 only minor differences from debugging statically linked programs.
7358 The `info proc' command will print out information about any process
7359 on an SVR4 system (including the one you are debugging). At the moment,
7360 it prints the address mappings of the process.
7362 If you bring up GDB on another SVR4 system, please send mail to
7363 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7365 * Better dynamic linking support in SunOS
7367 Reading symbols from shared libraries which contain debugging symbols
7368 now works properly. However, there remain issues such as automatic
7369 skipping of `transfer vector' code during function calls, which
7370 make it harder to debug code in a shared library, than to debug the
7371 same code linked statically.
7375 GDB is now using the latest `getopt' routines from the FSF. This
7376 version accepts the -- prefix for options with long names. GDB will
7377 continue to accept the old forms (-option and +option) as well.
7378 Various single letter abbreviations for options have been explicity
7379 added to the option table so that they won't get overshadowed in the
7380 future by other options that begin with the same letter.
7384 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7385 Many assorted bugs have been handled. Many more remain to be handled.
7386 See the various ChangeLog files (primarily in gdb and bfd) for details.
7389 *** Changes in GDB-4.3:
7391 * New machines supported (host and target)
7393 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7394 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7395 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7397 * Almost SCO Unix support
7399 We had hoped to support:
7400 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7401 (except for core file support), but we discovered very late in the release
7402 that it has problems with process groups that render gdb unusable. Sorry
7403 about that. I encourage people to fix it and post the fixes.
7405 * Preliminary ELF and DWARF support
7407 GDB can read ELF object files on System V Release 4, and can handle
7408 debugging records for C, in DWARF format, in ELF files. This support
7409 is preliminary. If you bring up GDB on another SVR4 system, please
7410 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7415 GDB now uses the latest `readline' library. One user-visible change
7416 is that two tabs will list possible command completions, which previously
7417 required typing M-? (meta-question mark, or ESC ?).
7421 The `stepi' bug that many of you noticed has been squashed.
7422 Many bugs in C++ have been handled. Many more remain to be handled.
7423 See the various ChangeLog files (primarily in gdb and bfd) for details.
7425 * State of the MIPS world (in case you wondered):
7427 GDB can understand the symbol tables emitted by the compilers
7428 supplied by most vendors of MIPS-based machines, including DEC. These
7429 symbol tables are in a format that essentially nobody else uses.
7431 Some versions of gcc come with an assembler post-processor called
7432 mips-tfile. This program is required if you want to do source-level
7433 debugging of gcc-compiled programs. I believe FSF does not ship
7434 mips-tfile with gcc version 1, but it will eventually come with gcc
7437 Debugging of g++ output remains a problem. g++ version 1.xx does not
7438 really support it at all. (If you're lucky, you should be able to get
7439 line numbers and stack traces to work, but no parameters or local
7440 variables.) With some work it should be possible to improve the
7443 When gcc version 2 is released, you will have somewhat better luck.
7444 However, even then you will get confusing results for inheritance and
7447 We will eventually provide full debugging of g++ output on
7448 DECstations. This will probably involve some kind of stabs-in-ecoff
7449 encapulation, but the details have not been worked out yet.
7452 *** Changes in GDB-4.2:
7454 * Improved configuration
7456 Only one copy of `configure' exists now, and it is not self-modifying.
7457 Porting BFD is simpler.
7461 The `step' and `next' commands now only stop at the first instruction
7462 of a source line. This prevents the multiple stops that used to occur
7463 in switch statements, for-loops, etc. `Step' continues to stop if a
7464 function that has debugging information is called within the line.
7468 Lots of small bugs fixed. More remain.
7470 * New host supported (not target)
7472 Intel 386 PC clone running Mach i386-none-mach
7475 *** Changes in GDB-4.1:
7477 * Multiple source language support
7479 GDB now has internal scaffolding to handle several source languages.
7480 It determines the type of each source file from its filename extension,
7481 and will switch expression parsing and number formatting to match the
7482 language of the function in the currently selected stack frame.
7483 You can also specifically set the language to be used, with
7484 `set language c' or `set language modula-2'.
7488 GDB now has preliminary support for the GNU Modula-2 compiler,
7489 currently under development at the State University of New York at
7490 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7491 continue through the fall of 1991 and into 1992.
7493 Other Modula-2 compilers are currently not supported, and attempting to
7494 debug programs compiled with them will likely result in an error as the
7495 symbol table is read. Feel free to work on it, though!
7497 There are hooks in GDB for strict type checking and range checking,
7498 in the `Modula-2 philosophy', but they do not currently work.
7502 GDB can now write to executable and core files (e.g. patch
7503 a variable's value). You must turn this switch on, specify
7504 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7505 by assigning a new value to a variable. Modifications take
7508 * Automatic SunOS shared library reading
7510 When you run your program, GDB automatically determines where its
7511 shared libraries (if any) have been loaded, and reads their symbols.
7512 The `share' command is no longer needed. This also works when
7513 examining core files.
7517 You can specify the number of lines that the `list' command shows.
7520 * New machines supported (host and target)
7522 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7523 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7524 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7526 * New hosts supported (not targets)
7528 IBM RT/PC: romp-ibm-aix or rtpc
7530 * New targets supported (not hosts)
7532 AMD 29000 embedded with COFF a29k-none-coff
7533 AMD 29000 embedded with a.out a29k-none-aout
7534 Ultracomputer remote kernel debug a29k-nyu-kern
7536 * New remote interfaces
7542 *** Changes in GDB-4.0:
7546 Wide output is wrapped at good places to make the output more readable.
7548 Gdb now supports cross-debugging from a host machine of one type to a
7549 target machine of another type. Communication with the target system
7550 is over serial lines. The ``target'' command handles connecting to the
7551 remote system; the ``load'' command will download a program into the
7552 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7553 also supports debugging of realtime processes running under VxWorks,
7554 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7555 stub on the target system.
7557 New CPUs supported include the AMD 29000 and Intel 960.
7559 GDB now reads object files and symbol tables via a ``binary file''
7560 library, which allows a single copy of GDB to debug programs of multiple
7561 object file types such as a.out and coff.
7563 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7564 refcard.dvi and refcard.ps are available to format it).
7567 * Control-Variable user interface simplified
7569 All variables that control the operation of the debugger can be set
7570 by the ``set'' command, and displayed by the ``show'' command.
7572 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7573 ``Show prompt'' produces the response:
7574 Gdb's prompt is new-gdb=>.
7576 What follows are the NEW set commands. The command ``help set'' will
7577 print a complete list of old and new set commands. ``help set FOO''
7578 will give a longer description of the variable FOO. ``show'' will show
7579 all of the variable descriptions and their current settings.
7581 confirm on/off: Enables warning questions for operations that are
7582 hard to recover from, e.g. rerunning the program while
7583 it is already running. Default is ON.
7585 editing on/off: Enables EMACS style command line editing
7586 of input. Previous lines can be recalled with
7587 control-P, the current line can be edited with control-B,
7588 you can search for commands with control-R, etc.
7591 history filename NAME: NAME is where the gdb command history
7592 will be stored. The default is .gdb_history,
7593 or the value of the environment variable
7596 history size N: The size, in commands, of the command history. The
7597 default is 256, or the value of the environment variable
7600 history save on/off: If this value is set to ON, the history file will
7601 be saved after exiting gdb. If set to OFF, the
7602 file will not be saved. The default is OFF.
7604 history expansion on/off: If this value is set to ON, then csh-like
7605 history expansion will be performed on
7606 command line input. The default is OFF.
7608 radix N: Sets the default radix for input and output. It can be set
7609 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7610 in the current radix, so "set radix 10" is always a no-op.
7612 height N: This integer value is the number of lines on a page. Default
7613 is 24, the current `stty rows'' setting, or the ``li#''
7614 setting from the termcap entry matching the environment
7617 width N: This integer value is the number of characters on a line.
7618 Default is 80, the current `stty cols'' setting, or the ``co#''
7619 setting from the termcap entry matching the environment
7622 Note: ``set screensize'' is obsolete. Use ``set height'' and
7623 ``set width'' instead.
7625 print address on/off: Print memory addresses in various command displays,
7626 such as stack traces and structure values. Gdb looks
7627 more ``symbolic'' if you turn this off; it looks more
7628 ``machine level'' with it on. Default is ON.
7630 print array on/off: Prettyprint arrays. New convenient format! Default
7633 print demangle on/off: Print C++ symbols in "source" form if on,
7636 print asm-demangle on/off: Same, for assembler level printouts
7639 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7642 * Support for Epoch Environment.
7644 The epoch environment is a version of Emacs v18 with windowing. One
7645 new command, ``inspect'', is identical to ``print'', except that if you
7646 are running in the epoch environment, the value is printed in its own
7650 * Support for Shared Libraries
7652 GDB can now debug programs and core files that use SunOS shared libraries.
7653 Symbols from a shared library cannot be referenced
7654 before the shared library has been linked with the program (this
7655 happens after you type ``run'' and before the function main() is entered).
7656 At any time after this linking (including when examining core files
7657 from dynamically linked programs), gdb reads the symbols from each
7658 shared library when you type the ``sharedlibrary'' command.
7659 It can be abbreviated ``share''.
7661 sharedlibrary REGEXP: Load shared object library symbols for files
7662 matching a unix regular expression. No argument
7663 indicates to load symbols for all shared libraries.
7665 info sharedlibrary: Status of loaded shared libraries.
7670 A watchpoint stops execution of a program whenever the value of an
7671 expression changes. Checking for this slows down execution
7672 tremendously whenever you are in the scope of the expression, but is
7673 quite useful for catching tough ``bit-spreader'' or pointer misuse
7674 problems. Some machines such as the 386 have hardware for doing this
7675 more quickly, and future versions of gdb will use this hardware.
7677 watch EXP: Set a watchpoint (breakpoint) for an expression.
7679 info watchpoints: Information about your watchpoints.
7681 delete N: Deletes watchpoint number N (same as breakpoints).
7682 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7683 enable N: Re-enables watchpoint number N (same as breakpoints).
7686 * C++ multiple inheritance
7688 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7691 * C++ exception handling
7693 Gdb now supports limited C++ exception handling. Besides the existing
7694 ability to breakpoint on an exception handler, gdb can breakpoint on
7695 the raising of an exception (before the stack is peeled back to the
7698 catch FOO: If there is a FOO exception handler in the dynamic scope,
7699 set a breakpoint to catch exceptions which may be raised there.
7700 Multiple exceptions (``catch foo bar baz'') may be caught.
7702 info catch: Lists all exceptions which may be caught in the
7703 current stack frame.
7706 * Minor command changes
7708 The command ``call func (arg, arg, ...)'' now acts like the print
7709 command, except it does not print or save a value if the function's result
7710 is void. This is similar to dbx usage.
7712 The ``up'' and ``down'' commands now always print the frame they end up
7713 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7714 frames without printing.
7716 * New directory command
7718 'dir' now adds directories to the FRONT of the source search path.
7719 The path starts off empty. Source files that contain debug information
7720 about the directory in which they were compiled can be found even
7721 with an empty path; Sun CC and GCC include this information. If GDB can't
7722 find your source file in the current directory, type "dir .".
7724 * Configuring GDB for compilation
7726 For normal use, type ``./configure host''. See README or gdb.texinfo
7729 GDB now handles cross debugging. If you are remotely debugging between
7730 two different machines, type ``./configure host -target=targ''.
7731 Host is the machine where GDB will run; targ is the machine
7732 where the program that you are debugging will run.