1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.3
6 * 'thread-exited' event is now available in the annotations interface.
8 * New built-in convenience variables $_gdb_major and $_gdb_minor
9 provide the GDB version. They are handy for conditionally using
10 features available only in or since specific GDB versions, in
11 scripts that should work error-free with many different versions,
12 such as in system-wide init files.
14 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
15 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
16 of the GDB settings and the GDB maintenance settings. They are handy
17 for changing the logic of user defined commands depending on the
20 * GDB now supports Thread Local Storage (TLS) variables on several
21 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
22 architectures require kernel changes. TLS is not yet supported for
23 amd64 and i386 process core dumps.
25 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
26 addresses that required unmasking are shown in the backtrace with the
29 * Two new convenience functions $_cimag and $_creal that extract the
30 imaginary and real parts respectively from complex numbers.
32 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
33 provide the exitcode or exit status of the shell commands launched by
34 GDB commands such as "shell", "pipe" and "make".
36 * The RX port now supports XML target descriptions.
38 * GDB now shows the Ada task names at more places, e.g. in task switching
41 * GDB can now be compiled with Python 3 on Windows.
43 * New convenience variable $_ada_exception holds the address of the
44 Ada exception being thrown. This is set by Ada-related catchpoints.
46 * GDB can now place breakpoints on nested functions and subroutines in
47 Fortran code. The '::' operator can be used between parent and
48 child scopes when placing breakpoints, for example:
50 (gdb) break outer_function::inner_function
52 The 'outer_function::' prefix is only needed if 'inner_function' is
53 not visible in the current scope.
55 * In addition to the system-wide gdbinit file, if configured with
56 --with-system-gdbinit-dir, GDB will now also load files in that directory
57 as system gdbinit files, unless the -nx or -n flag is provided. Files
58 with extensions .gdb, .py and .scm are supported as long as GDB was
59 compiled with support for that language.
63 ** The gdb.Value type has a new method 'format_string' which returns a
64 string representing the value. The formatting is controlled by the
65 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
66 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
67 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
69 ** gdb.Type has a new property 'objfile' which returns the objfile the
72 ** The frame information printed by the python frame filtering code
73 is now consistent with what the 'backtrace' command prints when
74 there are no filters, or when the 'backtrace' '-no-filters' option
77 ** The new function gdb.lookup_static_symbol can be used to look up
78 symbols with static linkage.
80 ** The new function gdb.lookup_static_symbols can be used to look up
81 all static symbols with static linkage.
83 ** gdb.Objfile has new methods 'lookup_global_symbol' and
84 'lookup_static_symbol' to lookup a symbol from this objfile only.
86 ** gdb.Block now supports the dictionary syntax for accessing symbols in
87 this block (e.g. block['local_variable']).
91 | [COMMAND] | SHELL_COMMAND
92 | -d DELIM COMMAND DELIM SHELL_COMMAND
93 pipe [COMMAND] | SHELL_COMMAND
94 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
95 Executes COMMAND and sends its output to SHELL_COMMAND.
96 With no COMMAND, repeat the last executed command
97 and send its output to SHELL_COMMAND.
99 with SETTING [VALUE] [-- COMMAND]
100 w SETTING [VALUE] [-- COMMAND]
101 Temporarily set SETTING, run COMMAND, and restore SETTING.
102 Usage: with SETTING -- COMMAND
103 With no COMMAND, repeats the last executed command.
104 SETTING is any GDB setting you can change with the "set"
105 subcommands. For example, 'with language c -- print someobj'
106 temporarily switches to the C language in order to print someobj.
107 Settings can be combined: 'w lang c -- w print elements unlimited --
108 usercmd' switches to the C language and runs usercmd with no limit
109 of array elements to print.
111 maint with SETTING [VALUE] [-- COMMAND]
112 Like "with", but works with "maintenance set" settings.
114 set may-call-functions [on|off]
115 show may-call-functions
116 This controls whether GDB will attempt to call functions in
117 the program, such as with expressions in the print command. It
118 defaults to on. Calling functions in the program being debugged
119 can have undesired side effects. It is now possible to forbid
120 such function calls. If function calls are forbidden, GDB will throw
121 an error when a command (such as print expression) calls a function
124 set print finish [on|off]
126 This controls whether the `finish' command will display the value
127 that is returned by the current function. When `off', the value is
128 still entered into the value history, but it is not printed. The
133 Allows deeply nested structures to be simplified when printing by
134 replacing deeply nested parts (beyond the max-depth) with ellipses.
135 The default max-depth is 20, but this can be set to unlimited to get
136 the old behavior back.
138 set logging debugredirect [on|off]
139 By default, GDB debug output will go to both the terminal and the logfile.
140 Set if you want debug output to go only to the log file.
142 set style title foreground COLOR
143 set style title background COLOR
144 set style title intensity VALUE
145 Control the styling of titles.
147 set style highlight foreground COLOR
148 set style highlight background COLOR
149 set style highlight intensity VALUE
150 Control the styling of highlightings.
152 maint set test-settings KIND
153 maint show test-settings KIND
154 A set of commands used by the testsuite for exercising the settings
157 maint set tui-resize-message [on|off]
158 maint show tui-resize-message
159 Control whether GDB prints a message each time the terminal is
160 resized when in TUI mode. This is primarily useful for testing the
163 set print frame-info [short-location|location|location-and-address
164 |source-and-location|source-line|auto]
165 show print frame-info
166 This controls what frame information is printed by the commands printing
167 a frame. This setting will e.g. influence the behaviour of 'backtrace',
168 'frame', 'stepi'. The python frame filtering also respect this setting.
169 The 'backtrace' '-frame-info' option can override this global setting.
171 info modules [-q] [REGEXP]
172 Return a list of Fortran modules matching REGEXP, or all modules if
175 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
176 Return a list of functions within all modules, grouped by module.
177 The list of functions can be restricted with the optional regular
178 expressions. MODULE_REGEXP matches against the module name,
179 TYPE_REGEXP matches against the function type signature, and REGEXP
180 matches against the function name.
182 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
183 Return a list of variables within all modules, grouped by module.
184 The list of variables can be restricted with the optional regular
185 expressions. MODULE_REGEXP matches against the module name,
186 TYPE_REGEXP matches against the variable type, and REGEXP matches
187 against the variable name.
192 The "help" command uses the title style to enhance the
193 readibility of its output by styling the classes and
197 Similarly to "help", the "apropos" command also uses the
198 title style for the command names. "apropos" accepts now
199 a flag "-v" (verbose) to show the full documentation
200 of matching commands and to use the highlight style to mark
201 the documentation parts matching REGEXP.
205 The GDB printf and eval commands can now print C-style and Ada-style
206 string convenience variables without calling functions in the program.
207 This allows to do formatted printing of strings without having
208 a running inferior, or when debugging a core dump.
210 info sources [-dirname | -basename] [--] [REGEXP]
211 This command has now optional arguments to only print the files
212 whose names match REGEXP. The arguments -dirname and -basename
213 allow to restrict matching respectively to the dirname and basename
217 The "show style" and its subcommands are now styling
218 a style name in their output using its own style, to help
219 the user visualize the different styles.
221 set print frame-arguments
222 The new value 'presence' indicates to only indicate the presence of
223 arguments using ..., instead of printing argument names and values.
225 set print raw-frame-arguments
226 show print raw-frame-arguments
228 These commands replace the similarly-named "set/show print raw
229 frame-arguments" commands (now with a dash instead of a space). The
230 old commands are now deprecated and may be removed in a future
233 maint test-options require-delimiter
234 maint test-options unknown-is-error
235 maint test-options unknown-is-operand
236 maint show test-options-completion-result
237 Commands used by the testsuite to validate the command options
240 focus, winheight, +, -, >, <
241 These commands are now case-sensitive.
243 * New command options, command completion
245 GDB now has a standard infrastructure to support dash-style command
246 options ('-OPT'). One benefit is that commands that use it can
247 easily support completion of command line arguments. Try "CMD
248 -[TAB]" or "help CMD" to find options supported by a command. Over
249 time, we intend to migrate most commands to this infrastructure. A
250 number of commands got support for new command options in this
253 ** The "print" and "compile print" commands now support a number of
254 options that allow overriding relevant global print settings as
255 set by "set print" subcommands:
259 -array-indexes [on|off]
260 -elements NUMBER|unlimited
264 -repeats NUMBER|unlimited
265 -static-members [on|off]
270 Note that because the "print"/"compile print" commands accept
271 arbitrary expressions which may look like options (including
272 abbreviations), if you specify any command option, then you must
273 use a double dash ("--") to mark the end of argument processing.
275 ** The "backtrace" command now supports a number of options that
276 allow overriding relevant global print settings as set by "set
277 backtrace" and "set print" subcommands:
279 -entry-values no|only|preferred|if-needed|both|compact|default
280 -frame-arguments all|scalars|none
281 -raw-frame-arguments [on|off]
282 -frame-info auto|source-line|location|source-and-location
283 |location-and-address|short-location
287 In addition, the full/no-filters/hide qualifiers are now also
288 exposed as command options too:
294 ** The "frame apply", "tfaas" and "faas" commands similarly now
295 support the following options:
300 ** The new "info sources" options -dirname and -basename options
301 are using the standard '-OPT' infrastructure.
303 All options above can also be abbreviated. The argument of boolean
304 (on/off) options can be 0/1 too, and also the argument is assumed
305 "on" if omitted. This allows writing compact command invocations,
308 (gdb) p -r -p -o 0 -- *myptr
310 The above is equivalent to:
312 (gdb) print -raw -pretty -object off -- *myptr
314 ** The "info types" command now supports the '-q' flag to disable
315 printing of some header information in a similar fashion to "info
316 variables" and "info functions".
318 ** The "info variables", "info functions", and "whereis" commands
319 now take a '-n' flag that excludes non-debug symbols (symbols
320 from the symbol table, not from the debug info such as DWARF)
323 * Completion improvements
325 ** GDB can now complete the options of the "thread apply all" and
326 "taas" commands, and their "-ascending" option can now be
329 ** GDB can now complete the options of the "info threads", "info
330 functions", "info variables", "info locals", and "info args"
333 ** GDB can now complete the options of the "compile file" and
334 "compile code" commands. The "compile file" command now
335 completes on filenames.
337 ** GDB can now complete the backtrace command's
338 "full/no-filters/hide" qualifiers.
340 * In settings, you can now abbreviate "unlimited".
342 E.g., "set print elements u" is now equivalent to "set print
348 This lists all the possible completions for the rest of the line, if it
349 were to be given as a command itself. This is intended for use by MI
350 frontends in cases when separate CLI and MI channels cannot be used.
352 -catch-throw, -catch-rethrow, and -catch-catch
353 These can be used to catch C++ exceptions in a similar fashion to
354 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
358 ** The default version of the MI interpreter is now 3 (-i=mi3).
360 ** The output of information about multi-location breakpoints (which is
361 syntactically incorrect in MI 2) has changed in MI 3. This affects
362 the following commands and events:
366 - =breakpoint-created
367 - =breakpoint-modified
369 The -fix-multi-location-breakpoint-output command can be used to enable
370 this behavior with previous MI versions.
372 ** Backtraces and frames include a new optional field addr_flags which is
373 given after the addr field. On AArch64 this contains PAC if the address
374 has been masked in the frame. On all other targets the field is not
379 The testsuite now creates the files gdb.cmd (containing the arguments
380 used to launch GDB) and gdb.in (containing all the commands sent to
381 GDB) in the output directory for each test script. Multiple invocations
382 are appended with .1, .2, .3 etc.
384 * Building GDB and GDBserver now requires GNU make >= 3.82.
386 Using another implementation of the make program or an earlier version of
387 GNU make to build GDB or GDBserver is not supported.
389 * Building GDB now requires GNU readline >= 7.0.
391 GDB now bundles GNU readline 8.0, but if you choose to use
392 --with-system-readline, only readline >= 7.0 can be used.
394 * The TUI SingleKey keymap is now named "SingleKey". This can be used
395 from .inputrc to bind keys in this keymap. This feature is only
396 available when gdb is built against GNU readline 8.0 or later.
398 * Removed targets and native configurations
400 GDB no longer supports debugging the Cell Broadband Engine. This includes
401 both debugging standalone Cell/B.E. SPU applications and integrated debugging
402 of Cell/B.E. applications that use both the PPU and SPU architectures.
408 * Removed targets and native configurations
410 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
413 *** Changes in GDB 8.3
415 * GDB and GDBserver now support access to additional registers on
416 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
419 * GDB now has experimental support for the compilation and injection of
420 C++ source code into the inferior. This beta release does not include
421 support for several language features, such as templates, constructors,
424 This feature requires GCC 7.1 or higher built with libcp1.so
427 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
428 can be passed using the '[ADDRESS]:PORT' notation, or the regular
429 'ADDRESS:PORT' method.
431 * DWARF index cache: GDB can now automatically save indices of DWARF
432 symbols on disk to speed up further loading of the same binaries.
434 * Ada task switching is now supported on aarch64-elf targets when
435 debugging a program using the Ravenscar Profile. For more information,
436 see the "Tasking Support when using the Ravenscar Profile" section
437 in the GDB user manual.
439 * GDB in batch mode now exits with status 1 if the last command to be
442 * The RISC-V target now supports target descriptions.
444 * System call catchpoints now support system call aliases on FreeBSD.
445 When the ABI of a system call changes in FreeBSD, this is
446 implemented by leaving a compatibility system call using the old ABI
447 at the existing number and allocating a new system call number for
448 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
449 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
450 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
451 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
452 so that a system call catchpoint for the 'kevent' system call will
453 catch invocations of both the 'kevent' and 'freebsd11_kevent'
454 binaries. This ensures that 'kevent' system calls are caught for
455 binaries using either the old or new ABIs.
457 * Terminal styling is now available for the CLI and the TUI. GNU
458 Source Highlight can additionally be used to provide styling of
459 source code snippets. See the "set style" commands, below, for more
462 * Removed support for old demangling styles arm, edg, gnu, hp and
467 set debug compile-cplus-types
468 show debug compile-cplus-types
469 Control the display of debug output about type conversion in the
470 C++ compile feature. Commands have no effect while compiliong
475 Control whether debug output about files/functions skipping is
478 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
479 Apply a command to some frames.
480 FLAG arguments allow to control what output to produce and how to handle
481 errors raised when applying COMMAND to a frame.
484 Apply a command to all threads (ignoring errors and empty output).
485 Shortcut for 'thread apply all -s COMMAND'.
488 Apply a command to all frames (ignoring errors and empty output).
489 Shortcut for 'frame apply all -s COMMAND'.
492 Apply a command to all frames of all threads (ignoring errors and empty
494 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
496 maint set dwarf unwinders (on|off)
497 maint show dwarf unwinders
498 Control whether DWARF unwinders can be used.
501 Display a list of open files for a process.
505 Changes to the "frame", "select-frame", and "info frame" CLI commands.
506 These commands all now take a frame specification which
507 is either a frame level, or one of the keywords 'level', 'address',
508 'function', or 'view' followed by a parameter. Selecting a frame by
509 address, or viewing a frame outside the current backtrace now
510 requires the use of a keyword. Selecting a frame by level is
511 unchanged. The MI comment "-stack-select-frame" is unchanged.
513 target remote FILENAME
514 target extended-remote FILENAME
515 If FILENAME is a Unix domain socket, GDB will attempt to connect
516 to this socket instead of opening FILENAME as a character device.
518 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
519 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
520 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
521 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
522 These commands can now print only the searched entities
523 matching the provided regexp(s), giving a condition
524 on the entity names or entity types. The flag -q disables
525 printing headers or informations messages.
531 These commands now determine the syntax for the shown entities
532 according to the language chosen by `set language'. In particular,
533 `set language auto' means to automatically choose the language of
536 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
537 The 'thread apply' command accepts new FLAG arguments.
538 FLAG arguments allow to control what output to produce and how to handle
539 errors raised when applying COMMAND to a thread.
541 set tui tab-width NCHARS
542 show tui tab-width NCHARS
543 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
545 set style enabled [on|off]
547 Enable or disable terminal styling. Styling is enabled by default
548 on most hosts, but disabled by default when in batch mode.
550 set style sources [on|off]
552 Enable or disable source code styling. Source code styling is
553 enabled by default, but only takes effect if styling in general is
554 enabled, and if GDB was linked with GNU Source Highlight.
556 set style filename foreground COLOR
557 set style filename background COLOR
558 set style filename intensity VALUE
559 Control the styling of file names.
561 set style function foreground COLOR
562 set style function background COLOR
563 set style function intensity VALUE
564 Control the styling of function names.
566 set style variable foreground COLOR
567 set style variable background COLOR
568 set style variable intensity VALUE
569 Control the styling of variable names.
571 set style address foreground COLOR
572 set style address background COLOR
573 set style address intensity VALUE
574 Control the styling of addresses.
578 ** The '-data-disassemble' MI command now accepts an '-a' option to
579 disassemble the whole function surrounding the given program
580 counter value or function name. Support for this feature can be
581 verified by using the "-list-features" command, which should
582 contain "data-disassemble-a-option".
584 ** Command responses and notifications that include a frame now include
585 the frame's architecture in a new "arch" attribute.
587 * New native configurations
589 GNU/Linux/RISC-V riscv*-*-linux*
590 FreeBSD/riscv riscv*-*-freebsd*
594 GNU/Linux/RISC-V riscv*-*-linux*
596 CSKY GNU/LINUX csky*-*-linux
597 FreeBSD/riscv riscv*-*-freebsd*
599 GNU/Linux/OpenRISC or1k*-*-linux*
603 GDB no longer supports native debugging on versions of MS-Windows
608 ** GDB no longer supports Python versions less than 2.6.
610 ** The gdb.Inferior type has a new 'progspace' property, which is the program
611 space associated to that inferior.
613 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
614 of objfiles associated to that program space.
616 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
617 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
620 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
621 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
622 correct and did not work properly.
624 ** The gdb.Value type has a new constructor, which is used to construct a
625 gdb.Value from a Python buffer object and a gdb.Type.
631 Enable or disable the undefined behavior sanitizer. This is
632 disabled by default, but passing --enable-ubsan=yes or
633 --enable-ubsan=auto to configure will enable it. Enabling this can
634 cause a performance penalty. The undefined behavior sanitizer was
635 first introduced in GCC 4.9.
637 *** Changes in GDB 8.2
639 * The 'set disassembler-options' command now supports specifying options
642 * The 'symbol-file' command now accepts an '-o' option to add a relative
643 offset to all sections.
645 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
646 a relative offset to all sections, but it allows to override the load
647 address of individual sections using '-s'.
649 * The 'add-symbol-file' command no longer requires the second argument
650 (address of the text section).
652 * The endianness used with the 'set endian auto' mode in the absence of
653 an executable selected for debugging is now the last endianness chosen
654 either by one of the 'set endian big' and 'set endian little' commands
655 or by inferring from the last executable used, rather than the startup
658 * The pager now allows a "c" response, meaning to disable the pager
659 for the rest of the current command.
661 * The commands 'info variables/functions/types' now show the source line
662 numbers of symbol definitions when available.
664 * 'info proc' now works on running processes on FreeBSD systems and core
665 files created on FreeBSD systems.
667 * C expressions can now use _Alignof, and C++ expressions can now use
670 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
671 the vector length while the process is running.
677 Control display of debugging info regarding the FreeBSD native target.
679 set|show varsize-limit
680 This new setting allows the user to control the maximum size of Ada
681 objects being printed when those objects have a variable type,
682 instead of that maximum size being hardcoded to 65536 bytes.
684 set|show record btrace cpu
685 Controls the processor to be used for enabling errata workarounds for
688 maint check libthread-db
689 Run integrity checks on the current inferior's thread debugging
692 maint set check-libthread-db (on|off)
693 maint show check-libthread-db
694 Control whether to run integrity checks on inferior specific thread
695 debugging libraries as they are loaded. The default is not to
700 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
702 ** The commands attached to a breakpoint can be set by assigning to
703 the breakpoint's "commands" field.
705 ** gdb.execute can now execute multi-line gdb commands.
707 ** The new functions gdb.convenience_variable and
708 gdb.set_convenience_variable can be used to get and set the value
709 of convenience variables.
711 ** A gdb.Parameter will no longer print the "set" help text on an
712 ordinary "set"; instead by default a "set" will be silent unless
713 the get_set_string method returns a non-empty string.
717 RiscV ELF riscv*-*-elf
719 * Removed targets and native configurations
721 m88k running OpenBSD m88*-*-openbsd*
722 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
723 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
724 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
726 * Aarch64/Linux hardware watchpoints improvements
728 Hardware watchpoints on unaligned addresses are now properly
729 supported when running Linux kernel 4.10 or higher: read and access
730 watchpoints are no longer spuriously missed, and all watchpoints
731 lengths between 1 and 8 bytes are supported. On older kernels,
732 watchpoints set on unaligned addresses are no longer missed, with
733 the tradeoff that there is a possibility of false hits being
738 --enable-codesign=CERT
739 This can be used to invoke "codesign -s CERT" after building gdb.
740 This option is useful on macOS, where code signing is required for
741 gdb to work properly.
743 --disable-gdbcli has been removed
744 This is now silently accepted, but does nothing.
746 *** Changes in GDB 8.1
748 * GDB now supports dynamically creating arbitrary register groups specified
749 in XML target descriptions. This allows for finer grain grouping of
750 registers on systems with a large amount of registers.
752 * The 'ptype' command now accepts a '/o' flag, which prints the
753 offsets and sizes of fields in a struct, like the pahole(1) tool.
755 * New "--readnever" command line option instructs GDB to not read each
756 symbol file's symbolic debug information. This makes startup faster
757 but at the expense of not being able to perform symbolic debugging.
758 This option is intended for use cases where symbolic debugging will
759 not be used, e.g., when you only need to dump the debuggee's core.
761 * GDB now uses the GNU MPFR library, if available, to emulate target
762 floating-point arithmetic during expression evaluation when the target
763 uses different floating-point formats than the host. At least version
764 3.1 of GNU MPFR is required.
766 * GDB now supports access to the guarded-storage-control registers and the
767 software-based guarded-storage broadcast control registers on IBM z14.
769 * On Unix systems, GDB now supports transmitting environment variables
770 that are to be set or unset to GDBserver. These variables will
771 affect the environment to be passed to the remote inferior.
773 To inform GDB of environment variables that are to be transmitted to
774 GDBserver, use the "set environment" command. Only user set
775 environment variables are sent to GDBserver.
777 To inform GDB of environment variables that are to be unset before
778 the remote inferior is started by the GDBserver, use the "unset
779 environment" command.
781 * Completion improvements
783 ** GDB can now complete function parameters in linespecs and
784 explicit locations without quoting. When setting breakpoints,
785 quoting around functions names to help with TAB-completion is
786 generally no longer necessary. For example, this now completes
789 (gdb) b function(in[TAB]
790 (gdb) b function(int)
792 Related, GDB is no longer confused with completing functions in
793 C++ anonymous namespaces:
796 (gdb) b (anonymous namespace)::[TAB][TAB]
797 (anonymous namespace)::a_function()
798 (anonymous namespace)::b_function()
800 ** GDB now has much improved linespec and explicit locations TAB
801 completion support, that better understands what you're
802 completing and offers better suggestions. For example, GDB no
803 longer offers data symbols as possible completions when you're
804 setting a breakpoint.
806 ** GDB now TAB-completes label symbol names.
808 ** The "complete" command now mimics TAB completion accurately.
810 * New command line options (gcore)
813 Dump all memory mappings.
815 * Breakpoints on C++ functions are now set on all scopes by default
817 By default, breakpoints on functions/methods are now interpreted as
818 specifying all functions with the given name ignoring missing
819 leading scopes (namespaces and classes).
821 For example, assuming a C++ program with symbols named:
826 both commands "break func()" and "break B::func()" set a breakpoint
829 You can use the new flag "-qualified" to override this. This makes
830 GDB interpret the specified function name as a complete
831 fully-qualified name instead. For example, using the same C++
832 program, the "break -q B::func" command sets a breakpoint on
833 "B::func", only. A parameter has been added to the Python
834 gdb.Breakpoint constructor to achieve the same result when creating
835 a breakpoint from Python.
837 * Breakpoints on functions marked with C++ ABI tags
839 GDB can now set breakpoints on functions marked with C++ ABI tags
840 (e.g., [abi:cxx11]). See here for a description of ABI tags:
841 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
843 Functions with a C++11 abi tag are demangled/displayed like this:
845 function[abi:cxx11](int)
848 You can now set a breakpoint on such functions simply as if they had
851 (gdb) b function(int)
853 Or if you need to disambiguate between tags, like:
855 (gdb) b function[abi:other_tag](int)
857 Tab completion was adjusted accordingly as well.
861 ** New events gdb.new_inferior, gdb.inferior_deleted, and
862 gdb.new_thread are emitted. See the manual for further
863 description of these.
865 ** A new function, "gdb.rbreak" has been added to the Python API.
866 This function allows the setting of a large number of breakpoints
867 via a regex pattern in Python. See the manual for further details.
869 ** Python breakpoints can now accept explicit locations. See the
870 manual for a further description of this feature.
873 * New features in the GDB remote stub, GDBserver
875 ** GDBserver is now able to start inferior processes with a
876 specified initial working directory.
878 The user can set the desired working directory to be used from
879 GDB using the new "set cwd" command.
881 ** New "--selftest" command line option runs some GDBserver self
882 tests. These self tests are disabled in releases.
884 ** On Unix systems, GDBserver now does globbing expansion and variable
885 substitution in inferior command line arguments.
887 This is done by starting inferiors using a shell, like GDB does.
888 See "set startup-with-shell" in the user manual for how to disable
889 this from GDB when using "target extended-remote". When using
890 "target remote", you can disable the startup with shell by using the
891 new "--no-startup-with-shell" GDBserver command line option.
893 ** On Unix systems, GDBserver now supports receiving environment
894 variables that are to be set or unset from GDB. These variables
895 will affect the environment to be passed to the inferior.
897 * When catching an Ada exception raised with a message, GDB now prints
898 the message in the catchpoint hit notification. In GDB/MI mode, that
899 information is provided as an extra field named "exception-message"
900 in the *stopped notification.
902 * Trait objects can now be inspected When debugging Rust code. This
903 requires compiler support which will appear in Rust 1.24.
907 QEnvironmentHexEncoded
908 Inform GDBserver of an environment variable that is to be passed to
909 the inferior when starting it.
912 Inform GDBserver of an environment variable that is to be unset
913 before starting the remote inferior.
916 Inform GDBserver that the environment should be reset (i.e.,
917 user-set environment variables should be unset).
920 Indicates whether the inferior must be started with a shell or not.
923 Tell GDBserver that the inferior to be started should use a specific
926 * The "maintenance print c-tdesc" command now takes an optional
927 argument which is the file name of XML target description.
929 * The "maintenance selftest" command now takes an optional argument to
930 filter the tests to be run.
932 * The "enable", and "disable" commands now accept a range of
933 breakpoint locations, e.g. "enable 1.3-5".
938 Set and show the current working directory for the inferior.
941 Set and show compilation command used for compiling and injecting code
942 with the 'compile' commands.
944 set debug separate-debug-file
945 show debug separate-debug-file
946 Control the display of debug output about separate debug file search.
948 set dump-excluded-mappings
949 show dump-excluded-mappings
950 Control whether mappings marked with the VM_DONTDUMP flag should be
951 dumped when generating a core file.
954 List the registered selftests.
957 Start the debugged program stopping at the first instruction.
960 Control display of debugging messages related to OpenRISC targets.
962 set|show print type nested-type-limit
963 Set and show the limit of nesting level for nested types that the
964 type printer will show.
966 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
969 * Safer/improved support for debugging with no debug info
971 GDB no longer assumes functions with no debug information return
974 This means that GDB now refuses to call such functions unless you
975 tell it the function's type, by either casting the call to the
976 declared return type, or by casting the function to a function
977 pointer of the right type, and calling that:
979 (gdb) p getenv ("PATH")
980 'getenv' has unknown return type; cast the call to its declared return type
981 (gdb) p (char *) getenv ("PATH")
982 $1 = 0x7fffffffe "/usr/local/bin:/"...
983 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
984 $2 = 0x7fffffffe "/usr/local/bin:/"...
986 Similarly, GDB no longer assumes that global variables with no debug
987 info have type 'int', and refuses to print the variable's value
988 unless you tell it the variable's type:
991 'var' has unknown type; cast it to its declared type
995 * New native configurations
997 FreeBSD/aarch64 aarch64*-*-freebsd*
998 FreeBSD/arm arm*-*-freebsd*
1002 FreeBSD/aarch64 aarch64*-*-freebsd*
1003 FreeBSD/arm arm*-*-freebsd*
1004 OpenRISC ELF or1k*-*-elf
1006 * Removed targets and native configurations
1008 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1010 *** Changes in GDB 8.0
1012 * GDB now supports access to the PKU register on GNU/Linux. The register is
1013 added by the Memory Protection Keys for Userspace feature which will be
1014 available in future Intel CPUs.
1016 * GDB now supports C++11 rvalue references.
1020 ** New functions to start, stop and access a running btrace recording.
1021 ** Rvalue references are now supported in gdb.Type.
1023 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1026 * Building GDB and GDBserver now requires a C++11 compiler.
1028 For example, GCC 4.8 or later.
1030 It is no longer possible to build GDB or GDBserver with a C
1031 compiler. The --disable-build-with-cxx configure option has been
1034 * Building GDB and GDBserver now requires GNU make >= 3.81.
1036 It is no longer supported to build GDB or GDBserver with another
1037 implementation of the make program or an earlier version of GNU make.
1039 * Native debugging on MS-Windows supports command-line redirection
1041 Command-line arguments used for starting programs on MS-Windows can
1042 now include redirection symbols supported by native Windows shells,
1043 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1044 as "run", "start", and "set args", as well as the corresponding MI
1047 * Support for thread names on MS-Windows.
1049 GDB now catches and handles the special exception that programs
1050 running on MS-Windows use to assign names to threads in the
1053 * Support for Java programs compiled with gcj has been removed.
1055 * User commands now accept an unlimited number of arguments.
1056 Previously, only up to 10 was accepted.
1058 * The "eval" command now expands user-defined command arguments.
1060 This makes it easier to process a variable number of arguments:
1065 eval "print $arg%d", $i
1070 * Target descriptions can now describe registers for sparc32 and sparc64.
1072 * GDB now supports DWARF version 5 (debug information format).
1073 Its .debug_names index is not yet supported.
1075 * New native configurations
1077 FreeBSD/mips mips*-*-freebsd
1081 Synopsys ARC arc*-*-elf32
1082 FreeBSD/mips mips*-*-freebsd
1084 * Removed targets and native configurations
1086 Alpha running FreeBSD alpha*-*-freebsd*
1087 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1092 Erases all the flash memory regions reported by the target.
1094 maint print arc arc-instruction address
1095 Print internal disassembler information about instruction at a given address.
1099 set disassembler-options
1100 show disassembler-options
1101 Controls the passing of target specific information to the disassembler.
1102 If it is necessary to specify more than one disassembler option then
1103 multiple options can be placed together into a comma separated list.
1104 The default value is the empty string. Currently, the only supported
1105 targets are ARM, PowerPC and S/390.
1110 Erases all the flash memory regions reported by the target. This is
1111 equivalent to the CLI command flash-erase.
1113 -file-list-shared-libraries
1114 List the shared libraries in the program. This is
1115 equivalent to the CLI command "info shared".
1118 Catchpoints stopping the program when Ada exceptions are
1119 handled. This is equivalent to the CLI command "catch handlers".
1121 *** Changes in GDB 7.12
1123 * GDB and GDBserver now build with a C++ compiler by default.
1125 The --enable-build-with-cxx configure option is now enabled by
1126 default. One must now explicitly configure with
1127 --disable-build-with-cxx in order to build with a C compiler. This
1128 option will be removed in a future release.
1130 * GDBserver now supports recording btrace without maintaining an active
1133 * GDB now supports a negative repeat count in the 'x' command to examine
1134 memory backward from the given address. For example:
1137 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1138 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1139 (gdb) x/-5i 0x0000000000400580
1140 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1141 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1142 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1143 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1144 0x40057b <main(int, char**)+25>:
1145 callq 0x400536 <Func1(int, char const*)>
1147 * Fortran: Support structures with fields of dynamic types and
1148 arrays of dynamic types.
1150 * The symbol dumping maintenance commands have new syntax.
1151 maint print symbols [-pc address] [--] [filename]
1152 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1153 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1154 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1155 maint print msymbols [-objfile objfile] [--] [filename]
1157 * GDB now supports multibit bitfields and enums in target register
1160 * New Python-based convenience function $_as_string(val), which returns
1161 the textual representation of a value. This function is especially
1162 useful to obtain the text label of an enum value.
1164 * Intel MPX bound violation handling.
1166 Segmentation faults caused by a Intel MPX boundary violation
1167 now display the kind of violation (upper or lower), the memory
1168 address accessed and the memory bounds, along with the usual
1169 signal received and code location.
1173 Program received signal SIGSEGV, Segmentation fault
1174 Upper bound violation while accessing address 0x7fffffffc3b3
1175 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1176 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1178 * Rust language support.
1179 GDB now supports debugging programs written in the Rust programming
1180 language. See https://www.rust-lang.org/ for more information about
1183 * Support for running interpreters on specified input/output devices
1185 GDB now supports a new mechanism that allows frontends to provide
1186 fully featured GDB console views, as a better alternative to
1187 building such views on top of the "-interpreter-exec console"
1188 command. See the new "new-ui" command below. With that command,
1189 frontends can now start GDB in the traditional command-line mode
1190 running in an embedded terminal emulator widget, and create a
1191 separate MI interpreter running on a specified i/o device. In this
1192 way, GDB handles line editing, history, tab completion, etc. in the
1193 console all by itself, and the GUI uses the separate MI interpreter
1194 for its own control and synchronization, invisible to the command
1197 * The "catch syscall" command catches groups of related syscalls.
1199 The "catch syscall" command now supports catching a group of related
1200 syscalls using the 'group:' or 'g:' prefix.
1205 skip -gfile file-glob-pattern
1206 skip -function function
1207 skip -rfunction regular-expression
1208 A generalized form of the skip command, with new support for
1209 glob-style file names and regular expressions for function names.
1210 Additionally, a file spec and a function spec may now be combined.
1212 maint info line-table REGEXP
1213 Display the contents of GDB's internal line table data struture.
1216 Run any GDB unit tests that were compiled in.
1219 Start a new user interface instance running INTERP as interpreter,
1220 using the TTY file for input/output.
1224 ** gdb.Breakpoint objects have a new attribute "pending", which
1225 indicates whether the breakpoint is pending.
1226 ** Three new breakpoint-related events have been added:
1227 gdb.breakpoint_created, gdb.breakpoint_modified, and
1228 gdb.breakpoint_deleted.
1230 signal-event EVENTID
1231 Signal ("set") the given MS-Windows event object. This is used in
1232 conjunction with the Windows JIT debugging (AeDebug) support, where
1233 the OS suspends a crashing process until a debugger can attach to
1234 it. Resuming the crashing process, in order to debug it, is done by
1235 signalling an event.
1237 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1238 was added in GDBserver, including JIT compiling fast tracepoint's
1239 conditional expression bytecode into native code.
1241 * Support for various remote target protocols and ROM monitors has
1244 target m32rsdi Remote M32R debugging over SDI
1245 target mips MIPS remote debugging protocol
1246 target pmon PMON ROM monitor
1247 target ddb NEC's DDB variant of PMON for Vr4300
1248 target rockhopper NEC RockHopper variant of PMON
1249 target lsi LSI variant of PMO
1251 * Support for tracepoints and fast tracepoints on powerpc-linux,
1252 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1253 including JIT compiling fast tracepoint's conditional expression
1254 bytecode into native code.
1256 * MI async record =record-started now includes the method and format used for
1257 recording. For example:
1259 =record-started,thread-group="i1",method="btrace",format="bts"
1261 * MI async record =thread-selected now includes the frame field. For example:
1263 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1267 Andes NDS32 nds32*-*-elf
1269 *** Changes in GDB 7.11
1271 * GDB now supports debugging kernel-based threads on FreeBSD.
1273 * Per-inferior thread numbers
1275 Thread numbers are now per inferior instead of global. If you're
1276 debugging multiple inferiors, GDB displays thread IDs using a
1277 qualified INF_NUM.THR_NUM form. For example:
1281 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1282 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1283 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1284 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1286 As consequence, thread numbers as visible in the $_thread
1287 convenience variable and in Python's InferiorThread.num attribute
1288 are no longer unique between inferiors.
1290 GDB now maintains a second thread ID per thread, referred to as the
1291 global thread ID, which is the new equivalent of thread numbers in
1292 previous releases. See also $_gthread below.
1294 For backwards compatibility, MI's thread IDs always refer to global
1297 * Commands that accept thread IDs now accept the qualified
1298 INF_NUM.THR_NUM form as well. For example:
1301 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1304 * In commands that accept a list of thread IDs, you can now refer to
1305 all threads of an inferior using a star wildcard. GDB accepts
1306 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1307 refer to all threads of the current inferior. For example, "info
1310 * You can use "info threads -gid" to display the global thread ID of
1313 * The new convenience variable $_gthread holds the global number of
1316 * The new convenience variable $_inferior holds the number of the
1319 * GDB now displays the ID and name of the thread that hit a breakpoint
1320 or received a signal, if your program is multi-threaded. For
1323 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1324 Thread 1 "main" received signal SIGINT, Interrupt.
1326 * Record btrace now supports non-stop mode.
1328 * Support for tracepoints on aarch64-linux was added in GDBserver.
1330 * The 'record instruction-history' command now indicates speculative execution
1331 when using the Intel Processor Trace recording format.
1333 * GDB now allows users to specify explicit locations, bypassing
1334 the linespec parser. This feature is also available to GDB/MI
1337 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1338 GDB now is able to debug both AArch64 applications and ARM applications
1341 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1342 including JIT compiling fast tracepoint's conditional expression bytecode
1345 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1347 * "info threads", "info inferiors", "info display", "info checkpoints"
1348 and "maint info program-spaces" now list the corresponding items in
1349 ascending ID order, for consistency with all other "info" commands.
1351 * In Ada, the overloads selection menu has been enhanced to display the
1352 parameter types and the return types for the matching overloaded subprograms.
1356 maint set target-non-stop (on|off|auto)
1357 maint show target-non-stop
1358 Control whether GDB targets always operate in non-stop mode even if
1359 "set non-stop" is "off". The default is "auto", meaning non-stop
1360 mode is enabled if supported by the target.
1362 maint set bfd-sharing
1363 maint show bfd-sharing
1364 Control the reuse of bfd objects.
1367 show debug bfd-cache
1368 Control display of debugging info regarding bfd caching.
1372 Control display of debugging info regarding FreeBSD threads.
1374 set remote multiprocess-extensions-packet
1375 show remote multiprocess-extensions-packet
1376 Set/show the use of the remote protocol multiprocess extensions.
1378 set remote thread-events
1379 show remote thread-events
1380 Set/show the use of thread create/exit events.
1382 set ada print-signatures on|off
1383 show ada print-signatures"
1384 Control whether parameter types and return types are displayed in overloads
1385 selection menus. It is activaled (@code{on}) by default.
1389 Controls the maximum size of memory, in bytes, that GDB will
1390 allocate for value contents. Prevents incorrect programs from
1391 causing GDB to allocate overly large buffers. Default is 64k.
1393 * The "disassemble" command accepts a new modifier: /s.
1394 It prints mixed source+disassembly like /m with two differences:
1395 - disassembled instructions are now printed in program order, and
1396 - and source for all relevant files is now printed.
1397 The "/m" option is now considered deprecated: its "source-centric"
1398 output hasn't proved useful in practice.
1400 * The "record instruction-history" command accepts a new modifier: /s.
1401 It behaves exactly like /m and prints mixed source+disassembly.
1403 * The "set scheduler-locking" command supports a new mode "replay".
1404 It behaves like "off" in record mode and like "on" in replay mode.
1406 * Support for various ROM monitors has been removed:
1408 target dbug dBUG ROM monitor for Motorola ColdFire
1409 target picobug Motorola picobug monitor
1410 target dink32 DINK32 ROM monitor for PowerPC
1411 target m32r Renesas M32R/D ROM monitor
1412 target mon2000 mon2000 ROM monitor
1413 target ppcbug PPCBUG ROM monitor for PowerPC
1415 * Support for reading/writing memory and extracting values on architectures
1416 whose memory is addressable in units of any integral multiple of 8 bits.
1419 Allows to break when an Ada exception is handled.
1421 * New remote packets
1424 Indicates that an exec system call was executed.
1426 exec-events feature in qSupported
1427 The qSupported packet allows GDB to request support for exec
1428 events using the new 'gdbfeature' exec-event, and the qSupported
1429 response can contain the corresponding 'stubfeature'. Set and
1430 show commands can be used to display whether these features are enabled.
1433 Equivalent to interrupting with the ^C character, but works in
1436 thread created stop reason (T05 create:...)
1437 Indicates that the thread was just created and is stopped at entry.
1439 thread exit stop reply (w exitcode;tid)
1440 Indicates that the thread has terminated.
1443 Enables/disables thread create and exit event reporting. For
1444 example, this is used in non-stop mode when GDB stops a set of
1445 threads and synchronously waits for the their corresponding stop
1446 replies. Without exit events, if one of the threads exits, GDB
1447 would hang forever not knowing that it should no longer expect a
1448 stop for that same thread.
1451 Indicates that there are no resumed threads left in the target (all
1452 threads are stopped). The remote stub reports support for this stop
1453 reply to GDB's qSupported query.
1456 Enables/disables catching syscalls from the inferior process.
1457 The remote stub reports support for this packet to GDB's qSupported query.
1459 syscall_entry stop reason
1460 Indicates that a syscall was just called.
1462 syscall_return stop reason
1463 Indicates that a syscall just returned.
1465 * Extended-remote exec events
1467 ** GDB now has support for exec events on extended-remote Linux targets.
1468 For such targets with Linux kernels 2.5.46 and later, this enables
1469 follow-exec-mode and exec catchpoints.
1471 set remote exec-event-feature-packet
1472 show remote exec-event-feature-packet
1473 Set/show the use of the remote exec event feature.
1475 * Thread names in remote protocol
1477 The reply to qXfer:threads:read may now include a name attribute for each
1480 * Target remote mode fork and exec events
1482 ** GDB now has support for fork and exec events on target remote mode
1483 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1484 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1485 fork and exec catchpoints.
1487 * Remote syscall events
1489 ** GDB now has support for catch syscall on remote Linux targets,
1490 currently enabled on x86/x86_64 architectures.
1492 set remote catch-syscall-packet
1493 show remote catch-syscall-packet
1494 Set/show the use of the remote catch syscall feature.
1498 ** The -var-set-format command now accepts the zero-hexadecimal
1499 format. It outputs data in hexadecimal format with zero-padding on the
1504 ** gdb.InferiorThread objects have a new attribute "global_num",
1505 which refers to the thread's global thread ID. The existing
1506 "num" attribute now refers to the thread's per-inferior number.
1507 See "Per-inferior thread numbers" above.
1508 ** gdb.InferiorThread objects have a new attribute "inferior", which
1509 is the Inferior object the thread belongs to.
1511 *** Changes in GDB 7.10
1513 * Support for process record-replay and reverse debugging on aarch64*-linux*
1514 targets has been added. GDB now supports recording of A64 instruction set
1515 including advance SIMD instructions.
1517 * Support for Sun's version of the "stabs" debug file format has been removed.
1519 * GDB now honors the content of the file /proc/PID/coredump_filter
1520 (PID is the process ID) on GNU/Linux systems. This file can be used
1521 to specify the types of memory mappings that will be included in a
1522 corefile. For more information, please refer to the manual page of
1523 "core(5)". GDB also has a new command: "set use-coredump-filter
1524 on|off". It allows to set whether GDB will read the content of the
1525 /proc/PID/coredump_filter file when generating a corefile.
1527 * The "info os" command on GNU/Linux can now display information on
1529 "info os cpus" Listing of all cpus/cores on the system
1531 * GDB has two new commands: "set serial parity odd|even|none" and
1532 "show serial parity". These allows to set or show parity for the
1535 * The "info source" command now displays the producer string if it was
1536 present in the debug info. This typically includes the compiler version
1537 and may include things like its command line arguments.
1539 * The "info dll", an alias of the "info sharedlibrary" command,
1540 is now available on all platforms.
1542 * Directory names supplied to the "set sysroot" commands may be
1543 prefixed with "target:" to tell GDB to access shared libraries from
1544 the target system, be it local or remote. This replaces the prefix
1545 "remote:". The default sysroot has been changed from "" to
1546 "target:". "remote:" is automatically converted to "target:" for
1547 backward compatibility.
1549 * The system root specified by "set sysroot" will be prepended to the
1550 filename of the main executable (if reported to GDB as absolute by
1551 the operating system) when starting processes remotely, and when
1552 attaching to already-running local or remote processes.
1554 * GDB now supports automatic location and retrieval of executable
1555 files from remote targets. Remote debugging can now be initiated
1556 using only a "target remote" or "target extended-remote" command
1557 (no "set sysroot" or "file" commands are required). See "New remote
1560 * The "dump" command now supports verilog hex format.
1562 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1564 * On GNU/Linux, GDB and gdbserver are now able to access executable
1565 and shared library files without a "set sysroot" command when
1566 attaching to processes running in different mount namespaces from
1567 the debugger. This makes it possible to attach to processes in
1568 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1569 See "New remote packets" below.
1571 * The "tui reg" command now provides completion for all of the
1572 available register groups, including target specific groups.
1574 * The HISTSIZE environment variable is no longer read when determining
1575 the size of GDB's command history. GDB now instead reads the dedicated
1576 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1577 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1582 ** Memory ports can now be unbuffered.
1586 ** gdb.Objfile objects have a new attribute "username",
1587 which is the name of the objfile as specified by the user,
1588 without, for example, resolving symlinks.
1589 ** You can now write frame unwinders in Python.
1590 ** gdb.Type objects have a new method "optimized_out",
1591 returning optimized out gdb.Value instance of this type.
1592 ** gdb.Value objects have new methods "reference_value" and
1593 "const_value" which return a reference to the value and a
1594 "const" version of the value respectively.
1598 maint print symbol-cache
1599 Print the contents of the symbol cache.
1601 maint print symbol-cache-statistics
1602 Print statistics of symbol cache usage.
1604 maint flush-symbol-cache
1605 Flush the contents of the symbol cache.
1609 Start branch trace recording using Branch Trace Store (BTS) format.
1612 Evaluate expression by using the compiler and print result.
1616 Explicit commands for enabling and disabling tui mode.
1619 set mpx bound on i386 and amd64
1620 Support for bound table investigation on Intel MPX enabled applications.
1624 Start branch trace recording using Intel Processor Trace format.
1627 Print information about branch tracing internals.
1629 maint btrace packet-history
1630 Print the raw branch tracing data.
1632 maint btrace clear-packet-history
1633 Discard the stored raw branch tracing data.
1636 Discard all branch tracing data. It will be fetched and processed
1637 anew by the next "record" command.
1642 Renamed from "set debug dwarf2-die".
1643 show debug dwarf-die
1644 Renamed from "show debug dwarf2-die".
1646 set debug dwarf-read
1647 Renamed from "set debug dwarf2-read".
1648 show debug dwarf-read
1649 Renamed from "show debug dwarf2-read".
1651 maint set dwarf always-disassemble
1652 Renamed from "maint set dwarf2 always-disassemble".
1653 maint show dwarf always-disassemble
1654 Renamed from "maint show dwarf2 always-disassemble".
1656 maint set dwarf max-cache-age
1657 Renamed from "maint set dwarf2 max-cache-age".
1658 maint show dwarf max-cache-age
1659 Renamed from "maint show dwarf2 max-cache-age".
1661 set debug dwarf-line
1662 show debug dwarf-line
1663 Control display of debugging info regarding DWARF line processing.
1666 show max-completions
1667 Set the maximum number of candidates to be considered during
1668 completion. The default value is 200. This limit allows GDB
1669 to avoid generating large completion lists, the computation of
1670 which can cause the debugger to become temporarily unresponsive.
1672 set history remove-duplicates
1673 show history remove-duplicates
1674 Control the removal of duplicate history entries.
1676 maint set symbol-cache-size
1677 maint show symbol-cache-size
1678 Control the size of the symbol cache.
1680 set|show record btrace bts buffer-size
1681 Set and show the size of the ring buffer used for branch tracing in
1683 The obtained size may differ from the requested size. Use "info
1684 record" to see the obtained buffer size.
1686 set debug linux-namespaces
1687 show debug linux-namespaces
1688 Control display of debugging info regarding Linux namespaces.
1690 set|show record btrace pt buffer-size
1691 Set and show the size of the ring buffer used for branch tracing in
1692 Intel Processor Trace format.
1693 The obtained size may differ from the requested size. Use "info
1694 record" to see the obtained buffer size.
1696 maint set|show btrace pt skip-pad
1697 Set and show whether PAD packets are skipped when computing the
1700 * The command 'thread apply all' can now support new option '-ascending'
1701 to call its specified command for all threads in ascending order.
1703 * Python/Guile scripting
1705 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1706 special section named `.debug_gdb_scripts'.
1708 * New remote packets
1710 qXfer:btrace-conf:read
1711 Return the branch trace configuration for the current thread.
1713 Qbtrace-conf:bts:size
1714 Set the requested ring buffer size for branch tracing in BTS format.
1717 Enable Intel Procesor Trace-based branch tracing for the current
1718 process. The remote stub reports support for this packet to GDB's
1721 Qbtrace-conf:pt:size
1722 Set the requested ring buffer size for branch tracing in Intel Processor
1726 Indicates a memory breakpoint instruction was executed, irrespective
1727 of whether it was GDB that planted the breakpoint or the breakpoint
1728 is hardcoded in the program. This is required for correct non-stop
1732 Indicates the target stopped for a hardware breakpoint. This is
1733 required for correct non-stop mode operation.
1736 Return information about files on the remote system.
1738 qXfer:exec-file:read
1739 Return the full absolute name of the file that was executed to
1740 create a process running on the remote system.
1743 Select the filesystem on which vFile: operations with filename
1744 arguments will operate. This is required for GDB to be able to
1745 access files on remote targets where the remote stub does not
1746 share a common filesystem with the inferior(s).
1749 Indicates that a fork system call was executed.
1752 Indicates that a vfork system call was executed.
1754 vforkdone stop reason
1755 Indicates that a vfork child of the specified process has executed
1756 an exec or exit, allowing the vfork parent to resume execution.
1758 fork-events and vfork-events features in qSupported
1759 The qSupported packet allows GDB to request support for fork and
1760 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1761 and the qSupported response can contain the corresponding
1762 'stubfeatures'. Set and show commands can be used to display
1763 whether these features are enabled.
1765 * Extended-remote fork events
1767 ** GDB now has support for fork events on extended-remote Linux
1768 targets. For targets with Linux kernels 2.5.60 and later, this
1769 enables follow-fork-mode and detach-on-fork for both fork and
1770 vfork, as well as fork and vfork catchpoints.
1772 * The info record command now shows the recording format and the
1773 branch tracing configuration for the current thread when using
1774 the btrace record target.
1775 For the BTS format, it shows the ring buffer size.
1777 * GDB now has support for DTrace USDT (Userland Static Defined
1778 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1780 * GDB now supports access to vector registers on S/390 GNU/Linux
1783 * Removed command line options
1785 -xdb HP-UX XDB compatibility mode.
1787 * Removed targets and native configurations
1789 HP/PA running HP-UX hppa*-*-hpux*
1790 Itanium running HP-UX ia64-*-hpux*
1792 * New configure options
1795 This configure option allows the user to build GDB with support for
1796 Intel Processor Trace (default: auto). This requires libipt.
1798 --with-libipt-prefix=PATH
1799 Specify the path to the version of libipt that GDB should use.
1800 $PATH/include should contain the intel-pt.h header and
1801 $PATH/lib should contain the libipt.so library.
1803 *** Changes in GDB 7.9.1
1807 ** Xmethods can now specify a result type.
1809 *** Changes in GDB 7.9
1811 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1815 ** You can now access frame registers from Python scripts.
1816 ** New attribute 'producer' for gdb.Symtab objects.
1817 ** gdb.Objfile objects have a new attribute "progspace",
1818 which is the gdb.Progspace object of the containing program space.
1819 ** gdb.Objfile objects have a new attribute "owner".
1820 ** gdb.Objfile objects have a new attribute "build_id",
1821 which is the build ID generated when the file was built.
1822 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1823 ** A new event "gdb.clear_objfiles" has been added, triggered when
1824 selecting a new file to debug.
1825 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1826 ** New function gdb.lookup_objfile.
1828 New events which are triggered when GDB modifies the state of the
1831 ** gdb.events.inferior_call_pre: Function call is about to be made.
1832 ** gdb.events.inferior_call_post: Function call has just been made.
1833 ** gdb.events.memory_changed: A memory location has been altered.
1834 ** gdb.events.register_changed: A register has been altered.
1836 * New Python-based convenience functions:
1838 ** $_caller_is(name [, number_of_frames])
1839 ** $_caller_matches(regexp [, number_of_frames])
1840 ** $_any_caller_is(name [, number_of_frames])
1841 ** $_any_caller_matches(regexp [, number_of_frames])
1843 * GDB now supports the compilation and injection of source code into
1844 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1845 to compile the source code to object code, and if successful, inject
1846 and execute that code within the current context of the inferior.
1847 Currently the C language is supported. The commands used to
1848 interface with this new feature are:
1850 compile code [-raw|-r] [--] [source code]
1851 compile file [-raw|-r] filename
1855 demangle [-l language] [--] name
1856 Demangle "name" in the specified language, or the current language
1857 if elided. This command is renamed from the "maint demangle" command.
1858 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1859 as "maint demangler-warning".
1861 queue-signal signal-name-or-number
1862 Queue a signal to be delivered to the thread when it is resumed.
1864 add-auto-load-scripts-directory directory
1865 Add entries to the list of directories from which to load auto-loaded
1868 maint print user-registers
1869 List all currently available "user" registers.
1871 compile code [-r|-raw] [--] [source code]
1872 Compile, inject, and execute in the inferior the executable object
1873 code produced by compiling the provided source code.
1875 compile file [-r|-raw] filename
1876 Compile and inject into the inferior the executable object code
1877 produced by compiling the source code stored in the filename
1880 * On resume, GDB now always passes the signal the program had stopped
1881 for to the thread the signal was sent to, even if the user changed
1882 threads before resuming. Previously GDB would often (but not
1883 always) deliver the signal to the thread that happens to be current
1886 * Conversely, the "signal" command now consistently delivers the
1887 requested signal to the current thread. GDB now asks for
1888 confirmation if the program had stopped for a signal and the user
1889 switched threads meanwhile.
1891 * "breakpoint always-inserted" modes "off" and "auto" merged.
1893 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1894 won't remove breakpoints from the target until all threads stop,
1895 even in non-stop mode. The "auto" mode has been removed, and "off"
1896 is now the default mode.
1900 set debug symbol-lookup
1901 show debug symbol-lookup
1902 Control display of debugging info regarding symbol lookup.
1906 ** The -list-thread-groups command outputs an exit-code field for
1907 inferiors that have exited.
1911 MIPS SDE mips*-sde*-elf*
1915 Support for these obsolete configurations has been removed.
1917 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1918 SGI Irix-5.x mips-*-irix5*
1919 SGI Irix-6.x mips-*-irix6*
1920 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1921 VAX running Ultrix vax-*-ultrix*
1923 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1924 and "assf"), have been removed. Use the "sharedlibrary" command, or
1925 its alias "share", instead.
1927 *** Changes in GDB 7.8
1929 * New command line options
1932 This is an alias for the --data-directory option.
1934 * GDB supports printing and modifying of variable length automatic arrays
1935 as specified in ISO C99.
1937 * The ARM simulator now supports instruction level tracing
1938 with or without disassembly.
1942 GDB now has support for scripting using Guile. Whether this is
1943 available is determined at configure time.
1944 Guile version 2.0 or greater is required.
1945 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1947 * New commands (for set/show, see "New options" below)
1951 Invoke CODE by passing it to the Guile interpreter.
1955 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1957 info auto-load guile-scripts [regexp]
1958 Print the list of automatically loaded Guile scripts.
1960 * The source command is now capable of sourcing Guile scripts.
1961 This feature is dependent on the debugger being built with Guile support.
1965 set print symbol-loading (off|brief|full)
1966 show print symbol-loading
1967 Control whether to print informational messages when loading symbol
1968 information for a file. The default is "full", but when debugging
1969 programs with large numbers of shared libraries the amount of output
1970 becomes less useful.
1972 set guile print-stack (none|message|full)
1973 show guile print-stack
1974 Show a stack trace when an error is encountered in a Guile script.
1976 set auto-load guile-scripts (on|off)
1977 show auto-load guile-scripts
1978 Control auto-loading of Guile script files.
1980 maint ada set ignore-descriptive-types (on|off)
1981 maint ada show ignore-descriptive-types
1982 Control whether the debugger should ignore descriptive types in Ada
1983 programs. The default is not to ignore the descriptive types. See
1984 the user manual for more details on descriptive types and the intended
1985 usage of this option.
1987 set auto-connect-native-target
1989 Control whether GDB is allowed to automatically connect to the
1990 native target for the run, attach, etc. commands when not connected
1991 to any target yet. See also "target native" below.
1993 set record btrace replay-memory-access (read-only|read-write)
1994 show record btrace replay-memory-access
1995 Control what memory accesses are allowed during replay.
1997 maint set target-async (on|off)
1998 maint show target-async
1999 This controls whether GDB targets operate in synchronous or
2000 asynchronous mode. Normally the default is asynchronous, if it is
2001 available; but this can be changed to more easily debug problems
2002 occurring only in synchronous mode.
2004 set mi-async (on|off)
2006 Control whether MI asynchronous mode is preferred. This supersedes
2007 "set target-async" of previous GDB versions.
2009 * "set target-async" is deprecated as a CLI option and is now an alias
2010 for "set mi-async" (only puts MI into async mode).
2012 * Background execution commands (e.g., "c&", "s&", etc.) are now
2013 possible ``out of the box'' if the target supports them. Previously
2014 the user would need to explicitly enable the possibility with the
2015 "set target-async on" command.
2017 * New features in the GDB remote stub, GDBserver
2019 ** New option --debug-format=option1[,option2,...] allows one to add
2020 additional text to each output. At present only timestamps
2021 are supported: --debug-format=timestamps.
2022 Timestamps can also be turned on with the
2023 "monitor set debug-format timestamps" command from GDB.
2025 * The 'record instruction-history' command now starts counting instructions
2026 at one. This also affects the instruction ranges reported by the
2027 'record function-call-history' command when given the /i modifier.
2029 * The command 'record function-call-history' supports a new modifier '/c' to
2030 indent the function names based on their call stack depth.
2031 The fields for the '/i' and '/l' modifier have been reordered.
2032 The source line range is now prefixed with 'at'.
2033 The instruction range is now prefixed with 'inst'.
2034 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2035 "record instruction-history" and "list" commands.
2037 * The ranges given as arguments to the 'record function-call-history' and
2038 'record instruction-history' commands are now inclusive.
2040 * The btrace record target now supports the 'record goto' command.
2041 For locations inside the execution trace, the back trace is computed
2042 based on the information stored in the execution trace.
2044 * The btrace record target supports limited reverse execution and replay.
2045 The target does not record data and therefore does not allow reading
2046 memory or registers.
2048 * The "catch syscall" command now works on s390*-linux* targets.
2050 * The "compare-sections" command is no longer specific to target
2051 remote. It now works with all targets.
2053 * All native targets are now consistently called "native".
2054 Consequently, the "target child", "target GNU", "target djgpp",
2055 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2056 commands have been replaced with "target native". The QNX/NTO port
2057 leaves the "procfs" target in place and adds a "native" target for
2058 consistency with other ports. The impact on users should be minimal
2059 as these commands previously either throwed an error, or were
2060 no-ops. The target's name is visible in the output of the following
2061 commands: "help target", "info target", "info files", "maint print
2064 * The "target native" command now connects to the native target. This
2065 can be used to launch native programs even when "set
2066 auto-connect-native-target" is set to off.
2068 * GDB now supports access to Intel MPX registers on GNU/Linux.
2070 * Support for Intel AVX-512 registers on GNU/Linux.
2071 Support displaying and modifying Intel AVX-512 registers
2072 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2074 * New remote packets
2076 qXfer:btrace:read's annex
2077 The qXfer:btrace:read packet supports a new annex 'delta' to read
2078 branch trace incrementally.
2082 ** Valid Python operations on gdb.Value objects representing
2083 structs/classes invoke the corresponding overloaded operators if
2085 ** New `Xmethods' feature in the Python API. Xmethods are
2086 additional methods or replacements for existing methods of a C++
2087 class. This feature is useful for those cases where a method
2088 defined in C++ source code could be inlined or optimized out by
2089 the compiler, making it unavailable to GDB.
2092 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2094 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2095 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2096 its alias "share", instead.
2098 * The commands "set remotebaud" and "show remotebaud" are no longer
2099 supported. Use "set serial baud" and "show serial baud" (respectively)
2104 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2105 target-async". The latter is left as a deprecated alias of the
2106 former for backward compatibility. If the target supports it,
2107 CLI background execution commands are now always possible by
2108 default, independently of whether the frontend stated a
2109 preference for asynchronous execution with "-gdb-set mi-async".
2110 Previously "-gdb-set target-async off" affected both MI execution
2111 commands and CLI execution commands.
2113 *** Changes in GDB 7.7
2115 * Improved support for process record-replay and reverse debugging on
2116 arm*-linux* targets. Support for thumb32 and syscall instruction
2117 recording has been added.
2119 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2121 * GDB now supports Fission DWP file format version 2.
2122 http://gcc.gnu.org/wiki/DebugFission
2124 * New convenience function "$_isvoid", to check whether an expression
2125 is void. A void expression is an expression where the type of the
2126 result is "void". For example, some convenience variables may be
2127 "void" when evaluated (e.g., "$_exitcode" before the execution of
2128 the program being debugged; or an undefined convenience variable).
2129 Another example, when calling a function whose return type is
2132 * The "maintenance print objfiles" command now takes an optional regexp.
2134 * The "catch syscall" command now works on arm*-linux* targets.
2136 * GDB now consistently shows "<not saved>" when printing values of
2137 registers the debug info indicates have not been saved in the frame
2138 and there's nowhere to retrieve them from
2139 (callee-saved/call-clobbered registers):
2144 (gdb) info registers rax
2147 Before, the former would print "<optimized out>", and the latter
2148 "*value not available*".
2150 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2155 ** Frame filters and frame decorators have been added.
2156 ** Temporary breakpoints are now supported.
2157 ** Line tables representation has been added.
2158 ** New attribute 'parent_type' for gdb.Field objects.
2159 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2160 ** New attribute 'name' for gdb.Type objects.
2164 Nios II ELF nios2*-*-elf
2165 Nios II GNU/Linux nios2*-*-linux
2166 Texas Instruments MSP430 msp430*-*-elf
2168 * Removed native configurations
2170 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2171 been removed. ELF variants of these configurations are kept supported.
2173 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2174 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2175 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2176 i[34567]86-*-openbsd3.[0-3]
2177 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2178 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2179 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2183 Like "catch throw", but catches a re-thrown exception.
2184 maint check-psymtabs
2185 Renamed from old "maint check-symtabs".
2187 Perform consistency checks on symtabs.
2188 maint expand-symtabs
2189 Expand symtabs matching an optional regexp.
2192 Display the details of GDB configure-time options.
2194 maint set|show per-command
2195 maint set|show per-command space
2196 maint set|show per-command time
2197 maint set|show per-command symtab
2198 Enable display of per-command gdb resource usage.
2200 remove-symbol-file FILENAME
2201 remove-symbol-file -a ADDRESS
2202 Remove a symbol file added via add-symbol-file. The file to remove
2203 can be identified by its filename or by an address that lies within
2204 the boundaries of this symbol file in memory.
2207 info exceptions REGEXP
2208 Display the list of Ada exceptions defined in the program being
2209 debugged. If provided, only the exceptions whose names match REGEXP
2214 set debug symfile off|on
2216 Control display of debugging info regarding reading symbol files and
2217 symbol tables within those files
2219 set print raw frame-arguments
2220 show print raw frame-arguments
2221 Set/show whether to print frame arguments in raw mode,
2222 disregarding any defined pretty-printers.
2224 set remote trace-status-packet
2225 show remote trace-status-packet
2226 Set/show the use of remote protocol qTStatus packet.
2230 Control display of debugging messages related to Nios II targets.
2234 Control whether target-assisted range stepping is enabled.
2236 set startup-with-shell
2237 show startup-with-shell
2238 Specifies whether Unix child processes are started via a shell or
2243 Use the target memory cache for accesses to the code segment. This
2244 improves performance of remote debugging (particularly disassembly).
2246 * You can now use a literal value 'unlimited' for options that
2247 interpret 0 or -1 as meaning "unlimited". E.g., "set
2248 trace-buffer-size unlimited" is now an alias for "set
2249 trace-buffer-size -1" and "set height unlimited" is now an alias for
2252 * The "set debug symtab-create" debugging option of GDB has been changed to
2253 accept a verbosity level. 0 means "off", 1 provides basic debugging
2254 output, and values of 2 or greater provides more verbose output.
2256 * New command-line options
2258 Display the details of GDB configure-time options.
2260 * The command 'tsave' can now support new option '-ctf' to save trace
2261 buffer in Common Trace Format.
2263 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2266 * GDB now implements the the C++ 'typeid' operator.
2268 * The new convenience variable $_exception holds the exception being
2269 thrown or caught at an exception-related catchpoint.
2271 * The exception-related catchpoints, like "catch throw", now accept a
2272 regular expression which can be used to filter exceptions by type.
2274 * The new convenience variable $_exitsignal is automatically set to
2275 the terminating signal number when the program being debugged dies
2276 due to an uncaught signal.
2280 ** All MI commands now accept an optional "--language" option.
2281 Support for this feature can be verified by using the "-list-features"
2282 command, which should contain "language-option".
2284 ** The new command -info-gdb-mi-command allows the user to determine
2285 whether a GDB/MI command is supported or not.
2287 ** The "^error" result record returned when trying to execute an undefined
2288 GDB/MI command now provides a variable named "code" whose content is the
2289 "undefined-command" error code. Support for this feature can be verified
2290 by using the "-list-features" command, which should contain
2291 "undefined-command-error-code".
2293 ** The -trace-save MI command can optionally save trace buffer in Common
2296 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2298 ** The command -data-list-register-values now accepts an optional
2299 "--skip-unavailable" option. When used, only the available registers
2302 ** The new command -trace-frame-collected dumps collected variables,
2303 computed expressions, tvars, memory and registers in a traceframe.
2305 ** The commands -stack-list-locals, -stack-list-arguments and
2306 -stack-list-variables now accept an option "--skip-unavailable".
2307 When used, only the available locals or arguments are displayed.
2309 ** The -exec-run command now accepts an optional "--start" option.
2310 When used, the command follows the same semantics as the "start"
2311 command, stopping the program's execution at the start of its
2312 main subprogram. Support for this feature can be verified using
2313 the "-list-features" command, which should contain
2314 "exec-run-start-option".
2316 ** The new commands -catch-assert and -catch-exceptions insert
2317 catchpoints stopping the program when Ada exceptions are raised.
2319 ** The new command -info-ada-exceptions provides the equivalent of
2320 the new "info exceptions" command.
2322 * New system-wide configuration scripts
2323 A GDB installation now provides scripts suitable for use as system-wide
2324 configuration scripts for the following systems:
2328 * GDB now supports target-assigned range stepping with remote targets.
2329 This improves the performance of stepping source lines by reducing
2330 the number of control packets from/to GDB. See "New remote packets"
2333 * GDB now understands the element 'tvar' in the XML traceframe info.
2334 It has the id of the collected trace state variables.
2336 * On S/390 targets that provide the transactional-execution feature,
2337 the program interruption transaction diagnostic block (TDB) is now
2338 represented as a number of additional "registers" in GDB.
2340 * New remote packets
2344 The vCont packet supports a new 'r' action, that tells the remote
2345 stub to step through an address range itself, without GDB
2346 involvemement at each single-step.
2348 qXfer:libraries-svr4:read's annex
2349 The previously unused annex of the qXfer:libraries-svr4:read packet
2350 is now used to support passing an argument list. The remote stub
2351 reports support for this argument list to GDB's qSupported query.
2352 The defined arguments are "start" and "prev", used to reduce work
2353 necessary for library list updating, resulting in significant
2356 * New features in the GDB remote stub, GDBserver
2358 ** GDBserver now supports target-assisted range stepping. Currently
2359 enabled on x86/x86_64 GNU/Linux targets.
2361 ** GDBserver now adds element 'tvar' in the XML in the reply to
2362 'qXfer:traceframe-info:read'. It has the id of the collected
2363 trace state variables.
2365 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2368 * New 'z' formatter for printing and examining memory, this displays the
2369 value as hexadecimal zero padded on the left to the size of the type.
2371 * GDB can now use Windows x64 unwinding data.
2373 * The "set remotebaud" command has been replaced by "set serial baud".
2374 Similarly, "show remotebaud" has been replaced by "show serial baud".
2375 The "set remotebaud" and "show remotebaud" commands are still available
2376 to provide backward compatibility with older versions of GDB.
2378 *** Changes in GDB 7.6
2380 * Target record has been renamed to record-full.
2381 Record/replay is now enabled with the "record full" command.
2382 This also affects settings that are associated with full record/replay
2383 that have been moved from "set/show record" to "set/show record full":
2385 set|show record full insn-number-max
2386 set|show record full stop-at-limit
2387 set|show record full memory-query
2389 * A new record target "record-btrace" has been added. The new target
2390 uses hardware support to record the control-flow of a process. It
2391 does not support replaying the execution, but it implements the
2392 below new commands for investigating the recorded execution log.
2393 This new recording method can be enabled using:
2397 The "record-btrace" target is only available on Intel Atom processors
2398 and requires a Linux kernel 2.6.32 or later.
2400 * Two new commands have been added for record/replay to give information
2401 about the recorded execution without having to replay the execution.
2402 The commands are only supported by "record btrace".
2404 record instruction-history prints the execution history at
2405 instruction granularity
2407 record function-call-history prints the execution history at
2408 function granularity
2410 * New native configurations
2412 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2413 FreeBSD/powerpc powerpc*-*-freebsd
2414 x86_64/Cygwin x86_64-*-cygwin*
2415 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2419 ARM AArch64 aarch64*-*-elf
2420 ARM AArch64 GNU/Linux aarch64*-*-linux
2421 Lynx 178 PowerPC powerpc-*-lynx*178
2422 x86_64/Cygwin x86_64-*-cygwin*
2423 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2425 * If the configured location of system.gdbinit file (as given by the
2426 --with-system-gdbinit option at configure time) is in the
2427 data-directory (as specified by --with-gdb-datadir at configure
2428 time) or in one of its subdirectories, then GDB will look for the
2429 system-wide init file in the directory specified by the
2430 --data-directory command-line option.
2432 * New command line options:
2434 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2435 other initialization files, unlike -nx which disables all of them.
2437 * Removed command line options
2439 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2442 * The 'ptype' and 'whatis' commands now accept an argument to control
2445 * 'info proc' now works on some core files.
2449 ** Vectors can be created with gdb.Type.vector.
2451 ** Python's atexit.register now works in GDB.
2453 ** Types can be pretty-printed via a Python API.
2455 ** Python 3 is now supported (in addition to Python 2.4 or later)
2457 ** New class gdb.Architecture exposes GDB's internal representation
2458 of architecture in the Python API.
2460 ** New method Frame.architecture returns the gdb.Architecture object
2461 corresponding to the frame's architecture.
2463 * New Python-based convenience functions:
2465 ** $_memeq(buf1, buf2, length)
2466 ** $_streq(str1, str2)
2468 ** $_regex(str, regex)
2470 * The 'cd' command now defaults to using '~' (the home directory) if not
2473 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2474 default for GCC since November 2000.
2476 * The command 'forward-search' can now be abbreviated as 'fo'.
2478 * The command 'info tracepoints' can now display 'installed on target'
2479 or 'not installed on target' for each non-pending location of tracepoint.
2481 * New configure options
2483 --enable-libmcheck/--disable-libmcheck
2484 By default, development versions are built with -lmcheck on hosts
2485 that support it, in order to help track memory corruption issues.
2486 Release versions, on the other hand, are built without -lmcheck
2487 by default. The --enable-libmcheck/--disable-libmcheck configure
2488 options allow the user to override that default.
2489 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2490 This configure option allows the user to build GDB with
2491 libbabeltrace using which GDB can read Common Trace Format data.
2493 * New commands (for set/show, see "New options" below)
2496 Catch signals. This is similar to "handle", but allows commands and
2497 conditions to be attached.
2500 List the BFDs known to GDB.
2502 python-interactive [command]
2504 Start a Python interactive prompt, or evaluate the optional command
2505 and print the result of expressions.
2508 "py" is a new alias for "python".
2510 enable type-printer [name]...
2511 disable type-printer [name]...
2512 Enable or disable type printers.
2516 ** For the Renesas Super-H architecture, the "regs" command has been removed
2517 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2522 set print type methods (on|off)
2523 show print type methods
2524 Control whether method declarations are displayed by "ptype".
2525 The default is to show them.
2527 set print type typedefs (on|off)
2528 show print type typedefs
2529 Control whether typedef definitions are displayed by "ptype".
2530 The default is to show them.
2532 set filename-display basename|relative|absolute
2533 show filename-display
2534 Control the way in which filenames is displayed.
2535 The default is "relative", which preserves previous behavior.
2537 set trace-buffer-size
2538 show trace-buffer-size
2539 Request target to change the size of trace buffer.
2541 set remote trace-buffer-size-packet auto|on|off
2542 show remote trace-buffer-size-packet
2543 Control the use of the remote protocol `QTBuffer:size' packet.
2547 Control display of debugging messages related to ARM AArch64.
2550 set debug coff-pe-read
2551 show debug coff-pe-read
2552 Control display of debugging messages related to reading of COFF/PE
2557 Control display of debugging messages related to Mach-O symbols
2560 set debug notification
2561 show debug notification
2562 Control display of debugging info for async remote notification.
2566 ** Command parameter changes are now notified using new async record
2567 "=cmd-param-changed".
2568 ** Trace frame changes caused by command "tfind" are now notified using
2569 new async record "=traceframe-changed".
2570 ** The creation, deletion and modification of trace state variables
2571 are now notified using new async records "=tsv-created",
2572 "=tsv-deleted" and "=tsv-modified".
2573 ** The start and stop of process record are now notified using new
2574 async record "=record-started" and "=record-stopped".
2575 ** Memory changes are now notified using new async record
2577 ** The data-disassemble command response will include a "fullname" field
2578 containing the absolute file name when source has been requested.
2579 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2580 command, to allow pattern filling of memory areas.
2581 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2582 library load/unload events.
2583 ** The response to breakpoint commands and breakpoint async records
2584 includes an "installed" field containing a boolean state about each
2585 non-pending tracepoint location is whether installed on target or not.
2586 ** Output of the "-trace-status" command includes a "trace-file" field
2587 containing the name of the trace file being examined. This field is
2588 optional, and only present when examining a trace file.
2589 ** The "fullname" field is now always present along with the "file" field,
2590 even if the file cannot be found by GDB.
2592 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2593 You must have the LZMA library available when configuring GDB for this
2594 feature to be enabled. For more information, see:
2595 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2597 * New remote packets
2600 Set the size of trace buffer. The remote stub reports support for this
2601 packet to gdb's qSupported query.
2604 Enable Branch Trace Store (BTS)-based branch tracing for the current
2605 thread. The remote stub reports support for this packet to gdb's
2609 Disable branch tracing for the current thread. The remote stub reports
2610 support for this packet to gdb's qSupported query.
2613 Read the traced branches for the current thread. The remote stub
2614 reports support for this packet to gdb's qSupported query.
2616 *** Changes in GDB 7.5
2618 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2619 for more x32 ABI info.
2621 * GDB now supports access to MIPS DSP registers on Linux targets.
2623 * GDB now supports debugging microMIPS binaries.
2625 * The "info os" command on GNU/Linux can now display information on
2626 several new classes of objects managed by the operating system:
2627 "info os procgroups" lists process groups
2628 "info os files" lists file descriptors
2629 "info os sockets" lists internet-domain sockets
2630 "info os shm" lists shared-memory regions
2631 "info os semaphores" lists semaphores
2632 "info os msg" lists message queues
2633 "info os modules" lists loaded kernel modules
2635 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2636 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2637 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2638 options and inspect the probe arguments using the new $_probe_arg family
2639 of convenience variables. You can obtain more information about SystemTap
2640 in <http://sourceware.org/systemtap/>.
2642 * GDB now supports reversible debugging on ARM, it allows you to
2643 debug basic ARM and THUMB instructions, and provides
2644 record/replay support.
2646 * The option "symbol-reloading" has been deleted as it is no longer used.
2650 ** GDB commands implemented in Python can now be put in command class
2653 ** The "maint set python print-stack on|off" is now deleted.
2655 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2656 apply "flag enum"-style pretty-printing to any enum.
2658 ** gdb.lookup_symbol can now work when there is no current frame.
2660 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2661 the source at which the symbol was defined.
2663 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2664 method 'value'. The former indicates whether the symbol needs a
2665 frame in order to compute its value, and the latter computes the
2668 ** A new method 'referenced_value' on gdb.Value objects which can
2669 dereference pointer as well as C++ reference values.
2671 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2672 which return the global and static blocks (as gdb.Block objects),
2673 of the underlying symbol table, respectively.
2675 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2676 object associated with a PC value.
2678 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2679 of the address range occupied by code for the current source line.
2681 * Go language support.
2682 GDB now supports debugging programs written in the Go programming
2685 * GDBserver now supports stdio connections.
2686 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2688 * The binary "gdbtui" can no longer be built or installed.
2689 Use "gdb -tui" instead.
2691 * GDB will now print "flag" enums specially. A flag enum is one where
2692 all the enumerator values have no bits in common when pairwise
2693 "and"ed. When printing a value whose type is a flag enum, GDB will
2694 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2695 (gdb) print (enum E) 3
2698 * The filename part of a linespec will now match trailing components
2699 of a source file name. For example, "break gcc/expr.c:1000" will
2700 now set a breakpoint in build/gcc/expr.c, but not
2701 build/libcpp/expr.c.
2703 * The "info proc" and "generate-core-file" commands will now also
2704 work on remote targets connected to GDBserver on Linux.
2706 * The command "info catch" has been removed. It has been disabled
2707 since December 2007.
2709 * The "catch exception" and "catch assert" commands now accept
2710 a condition at the end of the command, much like the "break"
2711 command does. For instance:
2713 (gdb) catch exception Constraint_Error if Barrier = True
2715 Previously, it was possible to add a condition to such catchpoints,
2716 but it had to be done as a second step, after the catchpoint had been
2717 created, using the "condition" command.
2719 * The "info static-tracepoint-marker" command will now also work on
2720 native Linux targets with in-process agent.
2722 * GDB can now set breakpoints on inlined functions.
2724 * The .gdb_index section has been updated to include symbols for
2725 inlined functions. GDB will ignore older .gdb_index sections by
2726 default, which could cause symbol files to be loaded more slowly
2727 until their .gdb_index sections can be recreated. The new command
2728 "set use-deprecated-index-sections on" will cause GDB to use any older
2729 .gdb_index sections it finds. This will restore performance, but the
2730 ability to set breakpoints on inlined functions will be lost in symbol
2731 files with older .gdb_index sections.
2733 The .gdb_index section has also been updated to record more information
2734 about each symbol. This speeds up the "info variables", "info functions"
2735 and "info types" commands when used with programs having the .gdb_index
2736 section, as well as speeding up debugging with shared libraries using
2737 the .gdb_index section.
2739 * Ada support for GDB/MI Variable Objects has been added.
2741 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2746 ** New command -info-os is the MI equivalent of "info os".
2748 ** Output logs ("set logging" and related) now include MI output.
2752 ** "set use-deprecated-index-sections on|off"
2753 "show use-deprecated-index-sections on|off"
2754 Controls the use of deprecated .gdb_index sections.
2756 ** "catch load" and "catch unload" can be used to stop when a shared
2757 library is loaded or unloaded, respectively.
2759 ** "enable count" can be used to auto-disable a breakpoint after
2762 ** "info vtbl" can be used to show the virtual method tables for
2763 C++ and Java objects.
2765 ** "explore" and its sub commands "explore value" and "explore type"
2766 can be used to recursively explore values and types of
2767 expressions. These commands are available only if GDB is
2768 configured with '--with-python'.
2770 ** "info auto-load" shows status of all kinds of auto-loaded files,
2771 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2772 sequences of commands files, "info auto-load python-scripts"
2773 shows status of auto-loading Python script files,
2774 "info auto-load local-gdbinit" shows status of loading init file
2775 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2776 status of inferior specific thread debugging shared library loading.
2778 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2779 and "show auto-load-scripts" commands have been deprecated, use their
2780 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2781 and "show auto-load python-scripts" counterparts instead.
2783 ** "dprintf location,format,args..." creates a dynamic printf, which
2784 is basically a breakpoint that does a printf and immediately
2785 resumes your program's execution, so it is like a printf that you
2786 can insert dynamically at runtime instead of at compiletime.
2788 ** "set print symbol"
2790 Controls whether GDB attempts to display the symbol, if any,
2791 corresponding to addresses it prints. This defaults to "on", but
2792 you can set it to "off" to restore GDB's previous behavior.
2794 * Deprecated commands
2796 ** For the Renesas Super-H architecture, the "regs" command has been
2797 deprecated, and "info all-registers" should be used instead.
2801 Renesas RL78 rl78-*-elf
2802 HP OpenVMS ia64 ia64-hp-openvms*
2804 * GDBserver supports evaluation of breakpoint conditions. When
2805 support is advertised by GDBserver, GDB may be told to send the
2806 breakpoint conditions in bytecode form to GDBserver. GDBserver
2807 will only report the breakpoint trigger to GDB when its condition
2812 set mips compression
2813 show mips compression
2814 Select the compressed ISA encoding used in functions that have no symbol
2815 information available. The encoding can be set to either of:
2818 and is updated automatically from ELF file flags if available.
2820 set breakpoint condition-evaluation
2821 show breakpoint condition-evaluation
2822 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2823 GDBserver ("target"). Default option "auto" chooses the most efficient
2825 This option can improve debugger efficiency depending on the speed of the
2829 Disable auto-loading globally.
2832 Show auto-loading setting of all kinds of auto-loaded files.
2834 set auto-load gdb-scripts on|off
2835 show auto-load gdb-scripts
2836 Control auto-loading of GDB canned sequences of commands files.
2838 set auto-load python-scripts on|off
2839 show auto-load python-scripts
2840 Control auto-loading of Python script files.
2842 set auto-load local-gdbinit on|off
2843 show auto-load local-gdbinit
2844 Control loading of init file (.gdbinit) from current directory.
2846 set auto-load libthread-db on|off
2847 show auto-load libthread-db
2848 Control auto-loading of inferior specific thread debugging shared library.
2850 set auto-load scripts-directory <dir1>[:<dir2>...]
2851 show auto-load scripts-directory
2852 Set a list of directories from which to load auto-loaded scripts.
2853 Automatically loaded Python scripts and GDB scripts are located in one
2854 of the directories listed by this option.
2855 The delimiter (':' above) may differ according to the host platform.
2857 set auto-load safe-path <dir1>[:<dir2>...]
2858 show auto-load safe-path
2859 Set a list of directories from which it is safe to auto-load files.
2860 The delimiter (':' above) may differ according to the host platform.
2862 set debug auto-load on|off
2863 show debug auto-load
2864 Control display of debugging info for auto-loading the files above.
2866 set dprintf-style gdb|call|agent
2868 Control the way in which a dynamic printf is performed; "gdb"
2869 requests a GDB printf command, while "call" causes dprintf to call a
2870 function in the inferior. "agent" requests that the target agent
2871 (such as GDBserver) do the printing.
2873 set dprintf-function <expr>
2874 show dprintf-function
2875 set dprintf-channel <expr>
2876 show dprintf-channel
2877 Set the function and optional first argument to the call when using
2878 the "call" style of dynamic printf.
2880 set disconnected-dprintf on|off
2881 show disconnected-dprintf
2882 Control whether agent-style dynamic printfs continue to be in effect
2883 after GDB disconnects.
2885 * New configure options
2887 --with-auto-load-dir
2888 Configure default value for the 'set auto-load scripts-directory'
2889 setting above. It defaults to '$debugdir:$datadir/auto-load',
2890 $debugdir representing global debugging info directories (available
2891 via 'show debug-file-directory') and $datadir representing GDB's data
2892 directory (available via 'show data-directory').
2894 --with-auto-load-safe-path
2895 Configure default value for the 'set auto-load safe-path' setting
2896 above. It defaults to the --with-auto-load-dir setting.
2898 --without-auto-load-safe-path
2899 Set 'set auto-load safe-path' to '/', effectively disabling this
2902 * New remote packets
2904 z0/z1 conditional breakpoints extension
2906 The z0/z1 breakpoint insertion packets have been extended to carry
2907 a list of conditional expressions over to the remote stub depending on the
2908 condition evaluation mode. The use of this extension can be controlled
2909 via the "set remote conditional-breakpoints-packet" command.
2913 Specify the signals which the remote stub may pass to the debugged
2914 program without GDB involvement.
2916 * New command line options
2918 --init-command=FILE, -ix Like --command, -x but execute it
2919 before loading inferior.
2920 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2921 execute it before loading inferior.
2923 *** Changes in GDB 7.4
2925 * GDB now handles ambiguous linespecs more consistently; the existing
2926 FILE:LINE support has been expanded to other types of linespecs. A
2927 breakpoint will now be set on all matching locations in all
2928 inferiors, and locations will be added or removed according to
2931 * GDB now allows you to skip uninteresting functions and files when
2932 stepping with the "skip function" and "skip file" commands.
2934 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2935 and "show remote hardware-watchpoint-length-limit". These allows to
2936 set or show the maximum length limit (in bytes) of a remote
2937 target hardware watchpoint.
2939 This allows e.g. to use "unlimited" hardware watchpoints with the
2940 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2941 watchpoints are slower than real hardware watchpoints but are
2942 significantly faster than gdb software watchpoints.
2946 ** The register_pretty_printer function in module gdb.printing now takes
2947 an optional `replace' argument. If True, the new printer replaces any
2950 ** The "maint set python print-stack on|off" command has been
2951 deprecated and will be deleted in GDB 7.5.
2952 A new command: "set python print-stack none|full|message" has
2953 replaced it. Additionally, the default for "print-stack" is
2954 now "message", which just prints the error message without
2957 ** A prompt substitution hook (prompt_hook) is now available to the
2960 ** A new Python module, gdb.prompt has been added to the GDB Python
2961 modules library. This module provides functionality for
2962 escape sequences in prompts (used by set/show
2963 extended-prompt). These escape sequences are replaced by their
2964 corresponding value.
2966 ** Python commands and convenience-functions located in
2967 'data-directory'/python/gdb/command and
2968 'data-directory'/python/gdb/function are now automatically loaded
2971 ** Blocks now provide four new attributes. global_block and
2972 static_block will return the global and static blocks
2973 respectively. is_static and is_global are boolean attributes
2974 that indicate if the block is one of those two types.
2976 ** Symbols now provide the "type" attribute, the type of the symbol.
2978 ** The "gdb.breakpoint" function has been deprecated in favor of
2981 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2982 of a function. This class is based on the "finish" command
2983 available in the CLI.
2985 ** Type objects for struct and union types now allow access to
2986 the fields using standard Python dictionary (mapping) methods.
2987 For example, "some_type['myfield']" now works, as does
2988 "some_type.items()".
2990 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2993 ** A new function, "deep_items" has been added to the gdb.types
2994 module in the GDB Python modules library. This function returns
2995 an iterator over the fields of a struct or union type. Unlike
2996 the standard Python "iteritems" method, it will recursively traverse
2997 any anonymous fields.
3001 ** "*stopped" events can report several new "reason"s, such as
3004 ** Breakpoint changes are now notified using new async records, like
3005 "=breakpoint-modified".
3007 ** New command -ada-task-info.
3009 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3010 $sdir specifies the default system locations of shared libraries.
3011 $pdir specifies the directory where the libpthread used by the application
3014 GDB no longer looks in $sdir and $pdir after it has searched the directories
3015 mentioned in libthread-db-search-path. If you want to search those
3016 directories, they must be specified in libthread-db-search-path.
3017 The default value of libthread-db-search-path on GNU/Linux and Solaris
3018 systems is now "$sdir:$pdir".
3020 $pdir is not supported by gdbserver, it is currently ignored.
3021 $sdir is supported by gdbserver.
3023 * New configure option --with-iconv-bin.
3024 When using the internationalization support like the one in the GNU C
3025 library, GDB will invoke the "iconv" program to get a list of supported
3026 character sets. If this program lives in a non-standard location, one can
3027 use this option to specify where to find it.
3029 * When natively debugging programs on PowerPC BookE processors running
3030 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3031 watchpoints, which specify a mask in addition to an address to watch.
3032 The mask specifies that some bits of an address (the bits which are
3033 reset in the mask) should be ignored when matching the address accessed
3034 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3035 section in the user manual for more details.
3037 * The new option --once causes GDBserver to stop listening for connections once
3038 the first connection is made. The listening port used by GDBserver will
3039 become available after that.
3041 * New commands "info macros" and "alias" have been added.
3043 * New function parameters suffix @entry specifies value of function parameter
3044 at the time the function got called. Entry values are available only since
3050 "!" is now an alias of the "shell" command.
3051 Note that no space is needed between "!" and SHELL COMMAND.
3055 watch EXPRESSION mask MASK_VALUE
3056 The watch command now supports the mask argument which allows creation
3057 of masked watchpoints, if the current architecture supports this feature.
3059 info auto-load-scripts [REGEXP]
3060 This command was formerly named "maintenance print section-scripts".
3061 It is now generally useful and is no longer a maintenance-only command.
3063 info macro [-all] [--] MACRO
3064 The info macro command has new options `-all' and `--'. The first for
3065 printing all definitions of a macro. The second for explicitly specifying
3066 the end of arguments and the beginning of the macro name in case the macro
3067 name starts with a hyphen.
3069 collect[/s] EXPRESSIONS
3070 The tracepoint collect command now takes an optional modifier "/s"
3071 that directs it to dereference pointer-to-character types and
3072 collect the bytes of memory up to a zero byte. The behavior is
3073 similar to what you see when you use the regular print command on a
3074 string. An optional integer following the "/s" sets a bound on the
3075 number of bytes that will be collected.
3078 The trace start command now interprets any supplied arguments as a
3079 note to be recorded with the trace run, with an effect similar to
3080 setting the variable trace-notes.
3083 The trace stop command now interprets any arguments as a note to be
3084 mentioned along with the tstatus report that the trace was stopped
3085 with a command. The effect is similar to setting the variable
3088 * Tracepoints can now be enabled and disabled at any time after a trace
3089 experiment has been started using the standard "enable" and "disable"
3090 commands. It is now possible to start a trace experiment with no enabled
3091 tracepoints; GDB will display a warning, but will allow the experiment to
3092 begin, assuming that tracepoints will be enabled as needed while the trace
3095 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3096 locations with 4-byte instructions, when they were previously
3097 limited to locations with instructions of 5 bytes or longer.
3101 set debug dwarf2-read
3102 show debug dwarf2-read
3103 Turns on or off display of debugging messages related to reading
3104 DWARF debug info. The default is off.
3106 set debug symtab-create
3107 show debug symtab-create
3108 Turns on or off display of debugging messages related to symbol table
3109 creation. The default is off.
3112 show extended-prompt
3113 Set the GDB prompt, and allow escape sequences to be inserted to
3114 display miscellaneous information (see 'help set extended-prompt'
3115 for the list of sequences). This prompt (and any information
3116 accessed through the escape sequences) is updated every time the
3117 prompt is displayed.
3119 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3120 show print entry-values
3121 Set printing of frame argument values at function entry. In some cases
3122 GDB can determine the value of function argument which was passed by the
3123 function caller, even if the value was modified inside the called function.
3125 set debug entry-values
3126 show debug entry-values
3127 Control display of debugging info for determining frame argument values at
3128 function entry and virtual tail call frames.
3130 set basenames-may-differ
3131 show basenames-may-differ
3132 Set whether a source file may have multiple base names.
3133 (A "base name" is the name of a file with the directory part removed.
3134 Example: The base name of "/home/user/hello.c" is "hello.c".)
3135 If set, GDB will canonicalize file names (e.g., expand symlinks)
3136 before comparing them. Canonicalization is an expensive operation,
3137 but it allows the same file be known by more than one base name.
3138 If not set (the default), all source files are assumed to have just
3139 one base name, and gdb will do file name comparisons more efficiently.
3145 Set a user name and notes for the current and any future trace runs.
3146 This is useful for long-running and/or disconnected traces, to
3147 inform others (or yourself) as to who is running the trace, supply
3148 contact information, or otherwise explain what is going on.
3150 set trace-stop-notes
3151 show trace-stop-notes
3152 Set a note attached to the trace run, that is displayed when the
3153 trace has been stopped by a tstop command. This is useful for
3154 instance as an explanation, if you are stopping a trace run that was
3155 started by someone else.
3157 * New remote packets
3161 Dynamically enable a tracepoint in a started trace experiment.
3165 Dynamically disable a tracepoint in a started trace experiment.
3169 Set the user and notes of the trace run.
3173 Query the current status of a tracepoint.
3177 Query the minimum length of instruction at which a fast tracepoint may
3180 * Dcache size (number of lines) and line-size are now runtime-configurable
3181 via "set dcache line" and "set dcache line-size" commands.
3185 Texas Instruments TMS320C6x tic6x-*-*
3189 Renesas RL78 rl78-*-elf
3191 *** Changes in GDB 7.3.1
3193 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3195 *** Changes in GDB 7.3
3197 * GDB has a new command: "thread find [REGEXP]".
3198 It finds the thread id whose name, target id, or thread extra info
3199 matches the given regular expression.
3201 * The "catch syscall" command now works on mips*-linux* targets.
3203 * The -data-disassemble MI command now supports modes 2 and 3 for
3204 dumping the instruction opcodes.
3206 * New command line options
3208 -data-directory DIR Specify DIR as the "data-directory".
3209 This is mostly for testing purposes.
3211 * The "maint set python auto-load on|off" command has been renamed to
3212 "set auto-load-scripts on|off".
3214 * GDB has a new command: "set directories".
3215 It is like the "dir" command except that it replaces the
3216 source path list instead of augmenting it.
3218 * GDB now understands thread names.
3220 On GNU/Linux, "info threads" will display the thread name as set by
3221 prctl or pthread_setname_np.
3223 There is also a new command, "thread name", which can be used to
3224 assign a name internally for GDB to display.
3227 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3228 has been integrated into GDB.
3232 ** The function gdb.Write now accepts an optional keyword 'stream'.
3233 This keyword, when provided, will direct the output to either
3234 stdout, stderr, or GDB's logging output.
3236 ** Parameters can now be be sub-classed in Python, and in particular
3237 you may implement the get_set_doc and get_show_doc functions.
3238 This improves how Parameter set/show documentation is processed
3239 and allows for more dynamic content.
3241 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3242 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3243 have an is_valid method.
3245 ** Breakpoints can now be sub-classed in Python, and in particular
3246 you may implement a 'stop' function that is executed each time
3247 the inferior reaches that breakpoint.
3249 ** New function gdb.lookup_global_symbol looks up a global symbol.
3251 ** GDB values in Python are now callable if the value represents a
3252 function. For example, if 'some_value' represents a function that
3253 takes two integer parameters and returns a value, you can call
3254 that function like so:
3256 result = some_value (10,20)
3258 ** Module gdb.types has been added.
3259 It contains a collection of utilities for working with gdb.Types objects:
3260 get_basic_type, has_field, make_enum_dict.
3262 ** Module gdb.printing has been added.
3263 It contains utilities for writing and registering pretty-printers.
3264 New classes: PrettyPrinter, SubPrettyPrinter,
3265 RegexpCollectionPrettyPrinter.
3266 New function: register_pretty_printer.
3268 ** New commands "info pretty-printers", "enable pretty-printer" and
3269 "disable pretty-printer" have been added.
3271 ** gdb.parameter("directories") is now available.
3273 ** New function gdb.newest_frame returns the newest frame in the
3276 ** The gdb.InferiorThread class has a new "name" attribute. This
3277 holds the thread's name.
3279 ** Python Support for Inferior events.
3280 Python scripts can add observers to be notified of events
3281 occurring in the process being debugged.
3282 The following events are currently supported:
3283 - gdb.events.cont Continue event.
3284 - gdb.events.exited Inferior exited event.
3285 - gdb.events.stop Signal received, and Breakpoint hit events.
3289 ** GDB now puts template parameters in scope when debugging in an
3290 instantiation. For example, if you have:
3292 template<int X> int func (void) { return X; }
3294 then if you step into func<5>, "print X" will show "5". This
3295 feature requires proper debuginfo support from the compiler; it
3296 was added to GCC 4.5.
3298 ** The motion commands "next", "finish", "until", and "advance" now
3299 work better when exceptions are thrown. In particular, GDB will
3300 no longer lose control of the inferior; instead, the GDB will
3301 stop the inferior at the point at which the exception is caught.
3302 This functionality requires a change in the exception handling
3303 code that was introduced in GCC 4.5.
3305 * GDB now follows GCC's rules on accessing volatile objects when
3306 reading or writing target state during expression evaluation.
3307 One notable difference to prior behavior is that "print x = 0"
3308 no longer generates a read of x; the value of the assignment is
3309 now always taken directly from the value being assigned.
3311 * GDB now has some support for using labels in the program's source in
3312 linespecs. For instance, you can use "advance label" to continue
3313 execution to a label.
3315 * GDB now has support for reading and writing a new .gdb_index
3316 section. This section holds a fast index of DWARF debugging
3317 information and can be used to greatly speed up GDB startup and
3318 operation. See the documentation for `save gdb-index' for details.
3320 * The "watch" command now accepts an optional "-location" argument.
3321 When used, this causes GDB to watch the memory referred to by the
3322 expression. Such a watchpoint is never deleted due to it going out
3325 * GDB now supports thread debugging of core dumps on GNU/Linux.
3327 GDB now activates thread debugging using the libthread_db library
3328 when debugging GNU/Linux core dumps, similarly to when debugging
3329 live processes. As a result, when debugging a core dump file, GDB
3330 is now able to display pthread_t ids of threads. For example, "info
3331 threads" shows the same output as when debugging the process when it
3332 was live. In earlier releases, you'd see something like this:
3335 * 1 LWP 6780 main () at main.c:10
3337 While now you see this:
3340 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3342 It is also now possible to inspect TLS variables when debugging core
3345 When debugging a core dump generated on a machine other than the one
3346 used to run GDB, you may need to point GDB at the correct
3347 libthread_db library with the "set libthread-db-search-path"
3348 command. See the user manual for more details on this command.
3350 * When natively debugging programs on PowerPC BookE processors running
3351 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3352 which stop execution of the inferior whenever it executes an instruction
3353 at any address within the specified range. See the "PowerPC Embedded"
3354 section in the user manual for more details.
3356 * New features in the GDB remote stub, GDBserver
3358 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3359 and i686 LynxOS (version 5.x).
3361 ** GDBserver is now supported on Blackfin Linux.
3363 * New native configurations
3365 ia64 HP-UX ia64-*-hpux*
3369 Analog Devices, Inc. Blackfin Processor bfin-*
3371 * Ada task switching is now supported on sparc-elf targets when
3372 debugging a program using the Ravenscar Profile. For more information,
3373 see the "Tasking Support when using the Ravenscar Profile" section
3374 in the GDB user manual.
3376 * Guile support was removed.
3378 * New features in the GNU simulator
3380 ** The --map-info flag lists all known core mappings.
3382 ** CFI flashes may be simulated via the "cfi" device.
3384 *** Changes in GDB 7.2
3386 * Shared library support for remote targets by default
3388 When GDB is configured for a generic, non-OS specific target, like
3389 for example, --target=arm-eabi or one of the many *-*-elf targets,
3390 GDB now queries remote stubs for loaded shared libraries using the
3391 `qXfer:libraries:read' packet. Previously, shared library support
3392 was always disabled for such configurations.
3396 ** Argument Dependent Lookup (ADL)
3398 In C++ ADL lookup directs function search to the namespaces of its
3399 arguments even if the namespace has not been imported.
3409 Here the compiler will search for `foo' in the namespace of 'b'
3410 and find A::foo. GDB now supports this. This construct is commonly
3411 used in the Standard Template Library for operators.
3413 ** Improved User Defined Operator Support
3415 In addition to member operators, GDB now supports lookup of operators
3416 defined in a namespace and imported with a `using' directive, operators
3417 defined in the global scope, operators imported implicitly from an
3418 anonymous namespace, and the ADL operators mentioned in the previous
3420 GDB now also supports proper overload resolution for all the previously
3421 mentioned flavors of operators.
3423 ** static const class members
3425 Printing of static const class members that are initialized in the
3426 class definition has been fixed.
3428 * Windows Thread Information Block access.
3430 On Windows targets, GDB now supports displaying the Windows Thread
3431 Information Block (TIB) structure. This structure is visible either
3432 by using the new command `info w32 thread-information-block' or, by
3433 dereferencing the new convenience variable named `$_tlb', a
3434 thread-specific pointer to the TIB. This feature is also supported
3435 when remote debugging using GDBserver.
3437 * Static tracepoints
3439 Static tracepoints are calls in the user program into a tracing
3440 library. One such library is a port of the LTTng kernel tracer to
3441 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3442 When debugging with GDBserver, GDB now supports combining the GDB
3443 tracepoint machinery with such libraries. For example: the user can
3444 use GDB to probe a static tracepoint marker (a call from the user
3445 program into the tracing library) with the new "strace" command (see
3446 "New commands" below). This creates a "static tracepoint" in the
3447 breakpoint list, that can be manipulated with the same feature set
3448 as fast and regular tracepoints. E.g., collect registers, local and
3449 global variables, collect trace state variables, and define
3450 tracepoint conditions. In addition, the user can collect extra
3451 static tracepoint marker specific data, by collecting the new
3452 $_sdata internal variable. When analyzing the trace buffer, you can
3453 inspect $_sdata like any other variable available to GDB. For more
3454 information, see the "Tracepoints" chapter in GDB user manual. New
3455 remote packets have been defined to support static tracepoints, see
3456 the "New remote packets" section below.
3458 * Better reconstruction of tracepoints after disconnected tracing
3460 GDB will attempt to download the original source form of tracepoint
3461 definitions when starting a trace run, and then will upload these
3462 upon reconnection to the target, resulting in a more accurate
3463 reconstruction of the tracepoints that are in use on the target.
3467 You can now exercise direct control over the ways that GDB can
3468 affect your program. For instance, you can disallow the setting of
3469 breakpoints, so that the program can run continuously (assuming
3470 non-stop mode). In addition, the "observer" variable is available
3471 to switch all of the different controls; in observer mode, GDB
3472 cannot affect the target's behavior at all, which is useful for
3473 tasks like diagnosing live systems in the field.
3475 * The new convenience variable $_thread holds the number of the
3478 * New remote packets
3482 Return the address of the Windows Thread Information Block of a given thread.
3486 In response to several of the tracepoint packets, the target may now
3487 also respond with a number of intermediate `qRelocInsn' request
3488 packets before the final result packet, to have GDB handle
3489 relocating an instruction to execute at a different address. This
3490 is particularly useful for stubs that support fast tracepoints. GDB
3491 reports support for this feature in the qSupported packet.
3495 List static tracepoint markers in the target program.
3499 List static tracepoint markers at a given address in the target
3502 qXfer:statictrace:read
3504 Read the static trace data collected (by a `collect $_sdata'
3505 tracepoint action). The remote stub reports support for this packet
3506 to gdb's qSupported query.
3510 Send the current settings of GDB's permission flags.
3514 Send part of the source (textual) form of a tracepoint definition,
3515 which includes location, conditional, and action list.
3517 * The source command now accepts a -s option to force searching for the
3518 script in the source search path even if the script name specifies
3521 * New features in the GDB remote stub, GDBserver
3523 - GDBserver now support tracepoints (including fast tracepoints, and
3524 static tracepoints). The feature is currently supported by the
3525 i386-linux and amd64-linux builds. See the "Tracepoints support
3526 in gdbserver" section in the manual for more information.
3528 GDBserver JIT compiles the tracepoint's conditional agent
3529 expression bytecode into native code whenever possible for low
3530 overhead dynamic tracepoints conditionals. For such tracepoints,
3531 an expression that examines program state is evaluated when the
3532 tracepoint is reached, in order to determine whether to capture
3533 trace data. If the condition is simple and false, processing the
3534 tracepoint finishes very quickly and no data is gathered.
3536 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3537 for static tracepoints support.
3539 - GDBserver now supports x86_64 Windows 64-bit debugging.
3541 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3542 it understands register description.
3544 * The --batch flag now disables pagination and queries.
3546 * X86 general purpose registers
3548 GDB now supports reading/writing byte, word and double-word x86
3549 general purpose registers directly. This means you can use, say,
3550 $ah or $ax to refer, respectively, to the byte register AH and
3551 16-bit word register AX that are actually portions of the 32-bit
3552 register EAX or 64-bit register RAX.
3554 * The `commands' command now accepts a range of breakpoints to modify.
3555 A plain `commands' following a command that creates multiple
3556 breakpoints affects all the breakpoints set by that command. This
3557 applies to breakpoints set by `rbreak', and also applies when a
3558 single `break' command creates multiple breakpoints (e.g.,
3559 breakpoints on overloaded c++ functions).
3561 * The `rbreak' command now accepts a filename specification as part of
3562 its argument, limiting the functions selected by the regex to those
3563 in the specified file.
3565 * Support for remote debugging Windows and SymbianOS shared libraries
3566 from Unix hosts has been improved. Non Windows GDB builds now can
3567 understand target reported file names that follow MS-DOS based file
3568 system semantics, such as file names that include drive letters and
3569 use the backslash character as directory separator. This makes it
3570 possible to transparently use the "set sysroot" and "set
3571 solib-search-path" on Unix hosts to point as host copies of the
3572 target's shared libraries. See the new command "set
3573 target-file-system-kind" described below, and the "Commands to
3574 specify files" section in the user manual for more information.
3578 eval template, expressions...
3579 Convert the values of one or more expressions under the control
3580 of the string template to a command line, and call it.
3582 set target-file-system-kind unix|dos-based|auto
3583 show target-file-system-kind
3584 Set or show the assumed file system kind for target reported file
3587 save breakpoints <filename>
3588 Save all current breakpoint definitions to a file suitable for use
3589 in a later debugging session. To read the saved breakpoint
3590 definitions, use the `source' command.
3592 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3595 info static-tracepoint-markers
3596 Display information about static tracepoint markers in the target.
3598 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3599 Define a static tracepoint by probing a marker at the given
3600 function, line, address, or marker ID.
3604 Enable and disable observer mode.
3606 set may-write-registers on|off
3607 set may-write-memory on|off
3608 set may-insert-breakpoints on|off
3609 set may-insert-tracepoints on|off
3610 set may-insert-fast-tracepoints on|off
3611 set may-interrupt on|off
3612 Set individual permissions for GDB effects on the target. Note that
3613 some of these settings can have undesirable or surprising
3614 consequences, particularly when changed in the middle of a session.
3615 For instance, disabling the writing of memory can prevent
3616 breakpoints from being inserted, cause single-stepping to fail, or
3617 even crash your program, if you disable after breakpoints have been
3618 inserted. However, GDB should not crash.
3620 set record memory-query on|off
3621 show record memory-query
3622 Control whether to stop the inferior if memory changes caused
3623 by an instruction cannot be recorded.
3628 The disassemble command now supports "start,+length" form of two arguments.
3632 ** GDB now provides a new directory location, called the python directory,
3633 where Python scripts written for GDB can be installed. The location
3634 of that directory is <data-directory>/python, where <data-directory>
3635 is the GDB data directory. For more details, see section `Scripting
3636 GDB using Python' in the manual.
3638 ** The GDB Python API now has access to breakpoints, symbols, symbol
3639 tables, program spaces, inferiors, threads and frame's code blocks.
3640 Additionally, GDB Parameters can now be created from the API, and
3641 manipulated via set/show in the CLI.
3643 ** New functions gdb.target_charset, gdb.target_wide_charset,
3644 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3646 ** New exception gdb.GdbError.
3648 ** Pretty-printers are now also looked up in the current program space.
3650 ** Pretty-printers can now be individually enabled and disabled.
3652 ** GDB now looks for names of Python scripts to auto-load in a
3653 special section named `.debug_gdb_scripts', in addition to looking
3654 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3656 * Tracepoint actions were unified with breakpoint commands. In particular,
3657 there are no longer differences in "info break" output for breakpoints and
3658 tracepoints and the "commands" command can be used for both tracepoints and
3659 regular breakpoints.
3663 ARM Symbian arm*-*-symbianelf*
3665 * D language support.
3666 GDB now supports debugging programs written in the D programming
3669 * GDB now supports the extended ptrace interface for PowerPC which is
3670 available since Linux kernel version 2.6.34. This automatically enables
3671 any hardware breakpoints and additional hardware watchpoints available in
3672 the processor. The old ptrace interface exposes just one hardware
3673 watchpoint and no hardware breakpoints.
3675 * GDB is now able to use the Data Value Compare (DVC) register available on
3676 embedded PowerPC processors to implement in hardware simple watchpoint
3677 conditions of the form:
3679 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3681 This works in native GDB running on Linux kernels with the extended ptrace
3682 interface mentioned above.
3684 *** Changes in GDB 7.1
3688 ** Namespace Support
3690 GDB now supports importing of namespaces in C++. This enables the
3691 user to inspect variables from imported namespaces. Support for
3692 namepace aliasing has also been added. So, if a namespace is
3693 aliased in the current scope (e.g. namepace C=A; ) the user can
3694 print variables using the alias (e.g. (gdb) print C::x).
3698 All known bugs relating to the printing of virtual base class were
3699 fixed. It is now possible to call overloaded static methods using a
3704 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3705 and reinterpret_cast<> are now handled by the C++ expression parser.
3709 Xilinx MicroBlaze microblaze-*-*
3714 Xilinx MicroBlaze microblaze
3717 * Multi-program debugging.
3719 GDB now has support for multi-program (a.k.a. multi-executable or
3720 multi-exec) debugging. This allows for debugging multiple inferiors
3721 simultaneously each running a different program under the same GDB
3722 session. See "Debugging Multiple Inferiors and Programs" in the
3723 manual for more information. This implied some user visible changes
3724 in the multi-inferior support. For example, "info inferiors" now
3725 lists inferiors that are not running yet or that have exited
3726 already. See also "New commands" and "New options" below.
3728 * New tracing features
3730 GDB's tracepoint facility now includes several new features:
3732 ** Trace state variables
3734 GDB tracepoints now include support for trace state variables, which
3735 are variables managed by the target agent during a tracing
3736 experiment. They are useful for tracepoints that trigger each
3737 other, so for instance one tracepoint can count hits in a variable,
3738 and then a second tracepoint has a condition that is true when the
3739 count reaches a particular value. Trace state variables share the
3740 $-syntax of GDB convenience variables, and can appear in both
3741 tracepoint actions and condition expressions. Use the "tvariable"
3742 command to create, and "info tvariables" to view; see "Trace State
3743 Variables" in the manual for more detail.
3747 GDB now includes an option for defining fast tracepoints, which
3748 targets may implement more efficiently, such as by installing a jump
3749 into the target agent rather than a trap instruction. The resulting
3750 speedup can be by two orders of magnitude or more, although the
3751 tradeoff is that some program locations on some target architectures
3752 might not allow fast tracepoint installation, for instance if the
3753 instruction to be replaced is shorter than the jump. To request a
3754 fast tracepoint, use the "ftrace" command, with syntax identical to
3755 the regular trace command.
3757 ** Disconnected tracing
3759 It is now possible to detach GDB from the target while it is running
3760 a trace experiment, then reconnect later to see how the experiment
3761 is going. In addition, a new variable disconnected-tracing lets you
3762 tell the target agent whether to continue running a trace if the
3763 connection is lost unexpectedly.
3767 GDB now has the ability to save the trace buffer into a file, and
3768 then use that file as a target, similarly to you can do with
3769 corefiles. You can select trace frames, print data that was
3770 collected in them, and use tstatus to display the state of the
3771 tracing run at the moment that it was saved. To create a trace
3772 file, use "tsave <filename>", and to use it, do "target tfile
3775 ** Circular trace buffer
3777 You can ask the target agent to handle the trace buffer as a
3778 circular buffer, discarding the oldest trace frames to make room for
3779 newer ones, by setting circular-trace-buffer to on. This feature may
3780 not be available for all target agents.
3785 The disassemble command, when invoked with two arguments, now requires
3786 the arguments to be comma-separated.
3789 The info variables command now displays variable definitions. Files
3790 which only declare a variable are not shown.
3793 The source command is now capable of sourcing Python scripts.
3794 This feature is dependent on the debugger being build with Python
3797 Related to this enhancement is also the introduction of a new command
3798 "set script-extension" (see below).
3800 * New commands (for set/show, see "New options" below)
3802 record save [<FILENAME>]
3803 Save a file (in core file format) containing the process record
3804 execution log for replay debugging at a later time.
3806 record restore <FILENAME>
3807 Restore the process record execution log that was saved at an
3808 earlier time, for replay debugging.
3810 add-inferior [-copies <N>] [-exec <FILENAME>]
3813 clone-inferior [-copies <N>] [ID]
3814 Make a new inferior ready to execute the same program another
3815 inferior has loaded.
3820 maint info program-spaces
3821 List the program spaces loaded into GDB.
3823 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3824 show remote interrupt-sequence
3825 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3826 as the sequence to the remote target in order to interrupt the execution.
3827 Ctrl-C is a default. Some system prefers BREAK which is high level of
3828 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3829 Magic SysRq g. It is BREAK signal and character 'g'.
3831 set remote interrupt-on-connect [on | off]
3832 show remote interrupt-on-connect
3833 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3834 remote target when gdb connects to it. This is needed when you debug
3837 set remotebreak [on | off]
3839 Deprecated. Use "set/show remote interrupt-sequence" instead.
3841 tvariable $NAME [ = EXP ]
3842 Create or modify a trace state variable.
3845 List trace state variables and their values.
3847 delete tvariable $NAME ...
3848 Delete one or more trace state variables.
3851 Evaluate the given expressions without collecting anything into the
3852 trace buffer. (Valid in tracepoint actions only.)
3854 ftrace FN / FILE:LINE / *ADDR
3855 Define a fast tracepoint at the given function, line, or address.
3857 * New expression syntax
3859 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3860 GDB now parses 0b101010 identically with 42.
3864 set follow-exec-mode new|same
3865 show follow-exec-mode
3866 Control whether GDB reuses the same inferior across an exec call or
3867 creates a new one. This is useful to be able to restart the old
3868 executable after the inferior having done an exec call.
3870 set default-collect EXPR, ...
3871 show default-collect
3872 Define a list of expressions to be collected at each tracepoint.
3873 This is a useful way to ensure essential items are not overlooked,
3874 such as registers or a critical global variable.
3876 set disconnected-tracing
3877 show disconnected-tracing
3878 If set to 1, the target is instructed to continue tracing if it
3879 loses its connection to GDB. If 0, the target is to stop tracing
3882 set circular-trace-buffer
3883 show circular-trace-buffer
3884 If set to on, the target is instructed to use a circular trace buffer
3885 and discard the oldest trace frames instead of stopping the trace due
3886 to a full trace buffer. If set to off, the trace stops when the buffer
3887 fills up. Some targets may not support this.
3889 set script-extension off|soft|strict
3890 show script-extension
3891 If set to "off", the debugger does not perform any script language
3892 recognition, and all sourced files are assumed to be GDB scripts.
3893 If set to "soft" (the default), files are sourced according to
3894 filename extension, falling back to GDB scripts if the first
3896 If set to "strict", files are sourced according to filename extension.
3898 set ada trust-PAD-over-XVS on|off
3899 show ada trust-PAD-over-XVS
3900 If off, activate a workaround against a bug in the debugging information
3901 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3902 the GCC sources for more information about the GNAT encoding and
3903 PAD types in particular). It is always safe to set this option to
3904 off, but this introduces a slight performance penalty. The default
3907 * Python API Improvements
3909 ** GDB provides the new class gdb.LazyString. This is useful in
3910 some pretty-printing cases. The new method gdb.Value.lazy_string
3911 provides a simple way to create objects of this type.
3913 ** The fields returned by gdb.Type.fields now have an
3914 `is_base_class' attribute.
3916 ** The new method gdb.Type.range returns the range of an array type.
3918 ** The new method gdb.parse_and_eval can be used to parse and
3919 evaluate an expression.
3921 * New remote packets
3924 Define a trace state variable.
3927 Get the current value of a trace state variable.
3930 Set desired tracing behavior upon disconnection.
3933 Set the trace buffer to be linear or circular.
3936 Get data about the tracepoints currently in use.
3940 Process record now works correctly with hardware watchpoints.
3942 Multiple bug fixes have been made to the mips-irix port, making it
3943 much more reliable. In particular:
3944 - Debugging threaded applications is now possible again. Previously,
3945 GDB would hang while starting the program, or while waiting for
3946 the program to stop at a breakpoint.
3947 - Attaching to a running process no longer hangs.
3948 - An error occurring while loading a core file has been fixed.
3949 - Changing the value of the PC register now works again. This fixes
3950 problems observed when using the "jump" command, or when calling
3951 a function from GDB, or even when assigning a new value to $pc.
3952 - With the "finish" and "return" commands, the return value for functions
3953 returning a small array is now correctly printed.
3954 - It is now possible to break on shared library code which gets executed
3955 during a shared library init phase (code executed while executing
3956 their .init section). Previously, the breakpoint would have no effect.
3957 - GDB is now able to backtrace through the signal handler for
3958 non-threaded programs.
3960 PIE (Position Independent Executable) programs debugging is now supported.
3961 This includes debugging execution of PIC (Position Independent Code) shared
3962 libraries although for that, it should be possible to run such libraries as an
3965 *** Changes in GDB 7.0
3967 * GDB now has an interface for JIT compilation. Applications that
3968 dynamically generate code can create symbol files in memory and register
3969 them with GDB. For users, the feature should work transparently, and
3970 for JIT developers, the interface is documented in the GDB manual in the
3971 "JIT Compilation Interface" chapter.
3973 * Tracepoints may now be conditional. The syntax is as for
3974 breakpoints; either an "if" clause appended to the "trace" command,
3975 or the "condition" command is available. GDB sends the condition to
3976 the target for evaluation using the same bytecode format as is used
3977 for tracepoint actions.
3979 * The disassemble command now supports: an optional /r modifier, print the
3980 raw instructions in hex as well as in symbolic form, and an optional /m
3981 modifier to print mixed source+assembly.
3983 * Process record and replay
3985 In a architecture environment that supports ``process record and
3986 replay'', ``process record and replay'' target can record a log of
3987 the process execution, and replay it with both forward and reverse
3990 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3991 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3992 set execution-direction {forward|reverse}, for targets that support
3995 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3996 feature is available with a native GDB running on kernel version
3999 * GDB now has support for multi-byte and wide character sets on the
4000 target. Strings whose character type is wchar_t, char16_t, or
4001 char32_t are now correctly printed. GDB supports wide- and unicode-
4002 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4003 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4004 `printf'. This feature requires iconv to work properly; if your
4005 system does not have a working iconv, GDB can use GNU libiconv. See
4006 the installation instructions for more information.
4008 * GDB now supports automatic retrieval of shared library files from
4009 remote targets. To use this feature, specify a system root that begins
4010 with the `remote:' prefix, either via the `set sysroot' command or via
4011 the `--with-sysroot' configure-time option.
4013 * "info sharedlibrary" now takes an optional regex of libraries to show,
4014 and it now reports if a shared library has no debugging information.
4016 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4017 now complete on file names.
4019 * When completing in expressions, gdb will attempt to limit
4020 completions to allowable structure or union fields, where appropriate.
4021 For instance, consider:
4023 # struct example { int f1; double f2; };
4024 # struct example variable;
4027 If the user types TAB at the end of this command line, the available
4028 completions will be "f1" and "f2".
4030 * Inlined functions are now supported. They show up in backtraces, and
4031 the "step", "next", and "finish" commands handle them automatically.
4033 * GDB now supports the token-splicing (##) and stringification (#)
4034 operators when expanding macros. It also supports variable-arity
4037 * GDB now supports inspecting extra signal information, exported by
4038 the new $_siginfo convenience variable. The feature is currently
4039 implemented on linux ARM, i386 and amd64.
4041 * GDB can now display the VFP floating point registers and NEON vector
4042 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4043 can provide these registers (requires Linux 2.6.30 or later). Remote
4044 and simulator targets may also provide them.
4046 * New remote packets
4049 Search memory for a sequence of bytes.
4052 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4053 operation over reliable transport links. Use of this packet is
4054 controlled by the `set remote noack-packet' command.
4057 Kill the process with the specified process ID. Use this in preference
4058 to `k' when multiprocess protocol extensions are supported.
4061 Obtains additional operating system information
4065 Read or write additional signal information.
4067 * Removed remote protocol undocumented extension
4069 An undocumented extension to the remote protocol's `S' stop reply
4070 packet that permited the stub to pass a process id was removed.
4071 Remote servers should use the `T' stop reply packet instead.
4073 * GDB now supports multiple function calling conventions according to the
4074 DWARF-2 DW_AT_calling_convention function attribute.
4076 * The SH target utilizes the aforementioned change to distinguish between gcc
4077 and Renesas calling convention. It also adds the new CLI commands
4078 `set/show sh calling-convention'.
4080 * GDB can now read compressed debug sections, as produced by GNU gold
4081 with the --compress-debug-sections=zlib flag.
4083 * 64-bit core files are now supported on AIX.
4085 * Thread switching is now supported on Tru64.
4087 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4088 which will be allocated using malloc later in program execution.
4090 * The qXfer:libraries:read remote procotol packet now allows passing a
4091 list of section offsets.
4093 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4094 conditions handling signals delivered during attach or thread creation
4095 have also been fixed.
4097 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4098 From the user's standpoint, all unqualified instances of True and False
4099 are treated as the standard definitions, regardless of context.
4101 * GDB now parses C++ symbol and type names more flexibly. For
4104 template<typename T> class C { };
4107 GDB will now correctly handle all of:
4109 ptype C<char const *>
4110 ptype C<char const*>
4111 ptype C<const char *>
4112 ptype C<const char*>
4114 * New features in the GDB remote stub, gdbserver
4116 - The "--wrapper" command-line argument tells gdbserver to use a
4117 wrapper program to launch programs for debugging.
4119 - On PowerPC and S/390 targets, it is now possible to use a single
4120 gdbserver executable to debug both 32-bit and 64-bit programs.
4121 (This requires gdbserver itself to be built as a 64-bit executable.)
4123 - gdbserver uses the new noack protocol mode for TCP connections to
4124 reduce communications latency, if also supported and enabled in GDB.
4126 - Support for the sparc64-linux-gnu target is now included in
4129 - The amd64-linux build of gdbserver now supports debugging both
4130 32-bit and 64-bit programs.
4132 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4133 now support hardware watchpoints, and will use them automatically
4138 GDB now has support for scripting using Python. Whether this is
4139 available is determined at configure time.
4141 New GDB commands can now be written in Python.
4143 * Ada tasking support
4145 Ada tasks can now be inspected in GDB. The following commands have
4149 Print the list of Ada tasks.
4151 Print detailed information about task number N.
4153 Print the task number of the current task.
4155 Switch the context of debugging to task number N.
4157 * Support for user-defined prefixed commands. The "define" command can
4158 add new commands to existing prefixes, e.g. "target".
4160 * Multi-inferior, multi-process debugging.
4162 GDB now has generalized support for multi-inferior debugging. See
4163 "Debugging Multiple Inferiors" in the manual for more information.
4164 Although availability still depends on target support, the command
4165 set is more uniform now. The GNU/Linux specific multi-forks support
4166 has been migrated to this new framework. This implied some user
4167 visible changes; see "New commands" and also "Removed commands"
4170 * Target descriptions can now describe the target OS ABI. See the
4171 "Target Description Format" section in the user manual for more
4174 * Target descriptions can now describe "compatible" architectures
4175 to indicate that the target can execute applications for a different
4176 architecture in addition to those for the main target architecture.
4177 See the "Target Description Format" section in the user manual for
4180 * Multi-architecture debugging.
4182 GDB now includes general supports for debugging applications on
4183 hybrid systems that use more than one single processor architecture
4184 at the same time. Each such hybrid architecture still requires
4185 specific support to be added. The only hybrid architecture supported
4186 in this version of GDB is the Cell Broadband Engine.
4188 * GDB now supports integrated debugging of Cell/B.E. applications that
4189 use both the PPU and SPU architectures. To enable support for hybrid
4190 Cell/B.E. debugging, you need to configure GDB to support both the
4191 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4192 --enable-targets configure option.
4194 * Non-stop mode debugging.
4196 For some targets, GDB now supports an optional mode of operation in
4197 which you can examine stopped threads while other threads continue
4198 to execute freely. This is referred to as non-stop mode, with the
4199 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4200 section in the user manual for more information.
4202 To be able to support remote non-stop debugging, a remote stub needs
4203 to implement the non-stop mode remote protocol extensions, as
4204 described in the "Remote Non-Stop" section of the user manual. The
4205 GDB remote stub, gdbserver, has been adjusted to support these
4206 extensions on linux targets.
4208 * New commands (for set/show, see "New options" below)
4210 catch syscall [NAME(S) | NUMBER(S)]
4211 Catch system calls. Arguments, which should be names of system
4212 calls or their numbers, mean catch only those syscalls. Without
4213 arguments, every syscall will be caught. When the inferior issues
4214 any of the specified syscalls, GDB will stop and announce the system
4215 call, both when it is called and when its call returns. This
4216 feature is currently available with a native GDB running on the
4217 Linux Kernel, under the following architectures: x86, x86_64,
4218 PowerPC and PowerPC64.
4220 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4222 Search memory for a sequence of bytes.
4224 maint set python print-stack
4225 maint show python print-stack
4226 Show a stack trace when an error is encountered in a Python script.
4229 Invoke CODE by passing it to the Python interpreter.
4234 These allow macros to be defined, undefined, and listed
4238 Show operating system information about processes.
4241 List the inferiors currently under GDB's control.
4244 Switch focus to inferior number NUM.
4247 Detach from inferior number NUM.
4250 Kill inferior number NUM.
4254 set spu stop-on-load
4255 show spu stop-on-load
4256 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4258 set spu auto-flush-cache
4259 show spu auto-flush-cache
4260 Control whether to automatically flush the software-managed cache
4261 during Cell/B.E. debugging.
4263 set sh calling-convention
4264 show sh calling-convention
4265 Control the calling convention used when calling SH target functions.
4268 show debug timestamp
4269 Control display of timestamps with GDB debugging output.
4271 set disassemble-next-line
4272 show disassemble-next-line
4273 Control display of disassembled source lines or instructions when
4276 set remote noack-packet
4277 show remote noack-packet
4278 Set/show the use of remote protocol QStartNoAckMode packet. See above
4279 under "New remote packets."
4281 set remote query-attached-packet
4282 show remote query-attached-packet
4283 Control use of remote protocol `qAttached' (query-attached) packet.
4285 set remote read-siginfo-object
4286 show remote read-siginfo-object
4287 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4290 set remote write-siginfo-object
4291 show remote write-siginfo-object
4292 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4295 set remote reverse-continue
4296 show remote reverse-continue
4297 Control use of remote protocol 'bc' (reverse-continue) packet.
4299 set remote reverse-step
4300 show remote reverse-step
4301 Control use of remote protocol 'bs' (reverse-step) packet.
4303 set displaced-stepping
4304 show displaced-stepping
4305 Control displaced stepping mode. Displaced stepping is a way to
4306 single-step over breakpoints without removing them from the debuggee.
4307 Also known as "out-of-line single-stepping".
4310 show debug displaced
4311 Control display of debugging info for displaced stepping.
4313 maint set internal-error
4314 maint show internal-error
4315 Control what GDB does when an internal error is detected.
4317 maint set internal-warning
4318 maint show internal-warning
4319 Control what GDB does when an internal warning is detected.
4324 Use a wrapper program to launch programs for debugging.
4326 set multiple-symbols (all|ask|cancel)
4327 show multiple-symbols
4328 The value of this variable can be changed to adjust the debugger behavior
4329 when an expression or a breakpoint location contains an ambiguous symbol
4330 name (an overloaded function name, for instance).
4332 set breakpoint always-inserted
4333 show breakpoint always-inserted
4334 Keep breakpoints always inserted in the target, as opposed to inserting
4335 them when resuming the target, and removing them when the target stops.
4336 This option can improve debugger performance on slow remote targets.
4338 set arm fallback-mode (arm|thumb|auto)
4339 show arm fallback-mode
4340 set arm force-mode (arm|thumb|auto)
4342 These commands control how ARM GDB determines whether instructions
4343 are ARM or Thumb. The default for both settings is auto, which uses
4344 the current CPSR value for instructions without symbols; previous
4345 versions of GDB behaved as if "set arm fallback-mode arm".
4347 set disable-randomization
4348 show disable-randomization
4349 Standalone programs run with the virtual address space randomization enabled
4350 by default on some platforms. This option keeps the addresses stable across
4351 multiple debugging sessions.
4355 Control whether other threads are stopped or not when some thread hits
4360 Requests that asynchronous execution is enabled in the target, if available.
4361 In this case, it's possible to resume target in the background, and interact
4362 with GDB while the target is running. "show target-async" displays the
4363 current state of asynchronous execution of the target.
4365 set target-wide-charset
4366 show target-wide-charset
4367 The target-wide-charset is the name of the character set that GDB
4368 uses when printing characters whose type is wchar_t.
4370 set tcp auto-retry (on|off)
4372 set tcp connect-timeout
4373 show tcp connect-timeout
4374 These commands allow GDB to retry failed TCP connections to a remote stub
4375 with a specified timeout period; this is useful if the stub is launched
4376 in parallel with GDB but may not be ready to accept connections immediately.
4378 set libthread-db-search-path
4379 show libthread-db-search-path
4380 Control list of directories which GDB will search for appropriate
4383 set schedule-multiple (on|off)
4384 show schedule-multiple
4385 Allow GDB to resume all threads of all processes or only threads of
4386 the current process.
4390 Use more aggressive caching for accesses to the stack. This improves
4391 performance of remote debugging (particularly backtraces) without
4392 affecting correctness.
4394 set interactive-mode (on|off|auto)
4395 show interactive-mode
4396 Control whether GDB runs in interactive mode (on) or not (off).
4397 When in interactive mode, GDB waits for the user to answer all
4398 queries. Otherwise, GDB does not wait and assumes the default
4399 answer. When set to auto (the default), GDB determines which
4400 mode to use based on the stdin settings.
4405 For program forks, this is replaced by the new more generic `info
4406 inferiors' command. To list checkpoints, you can still use the
4407 `info checkpoints' command, which was an alias for the `info forks'
4411 Replaced by the new `inferior' command. To switch between
4412 checkpoints, you can still use the `restart' command, which was an
4413 alias for the `fork' command.
4416 This is removed, since some targets don't have a notion of
4417 processes. To switch between processes, you can still use the
4418 `inferior' command using GDB's own inferior number.
4421 For program forks, this is replaced by the new more generic `kill
4422 inferior' command. To delete a checkpoint, you can still use the
4423 `delete checkpoint' command, which was an alias for the `delete
4427 For program forks, this is replaced by the new more generic `detach
4428 inferior' command. To detach a checkpoint, you can still use the
4429 `detach checkpoint' command, which was an alias for the `detach
4432 * New native configurations
4434 x86/x86_64 Darwin i[34567]86-*-darwin*
4436 x86_64 MinGW x86_64-*-mingw*
4440 Lattice Mico32 lm32-*
4441 x86 DICOS i[34567]86-*-dicos*
4442 x86_64 DICOS x86_64-*-dicos*
4445 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4446 (mingw32ce) debugging.
4452 These commands were actually not implemented on any target.
4454 *** Changes in GDB 6.8
4456 * New native configurations
4458 NetBSD/hppa hppa*-*netbsd*
4459 Xtensa GNU/Linux xtensa*-*-linux*
4463 NetBSD/hppa hppa*-*-netbsd*
4464 Xtensa GNU/Lunux xtensa*-*-linux*
4466 * Change in command line behavior -- corefiles vs. process ids.
4468 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4469 attaching to process NUMBER fails, GDB no longer attempts to open a
4470 core file named NUMBER. Attaching to a program using the -c option
4471 is no longer supported. Instead, use the '-p' or '--pid' options.
4473 * GDB can now be built as a native debugger for debugging Windows x86
4474 (mingw32) Portable Executable (PE) programs.
4476 * Pending breakpoints no longer change their number when their address
4479 * GDB now supports breakpoints with multiple locations,
4480 including breakpoints on C++ constructors, inside C++ templates,
4481 and in inlined functions.
4483 * GDB's ability to debug optimized code has been improved. GDB more
4484 accurately identifies function bodies and lexical blocks that occupy
4485 more than one contiguous range of addresses.
4487 * Target descriptions can now describe registers for PowerPC.
4489 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4490 registers on PowerPC targets.
4492 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4493 targets even when the libthread_db library is not available.
4495 * The GDB remote stub, gdbserver, now supports the new file transfer
4496 commands (remote put, remote get, and remote delete).
4498 * The GDB remote stub, gdbserver, now supports run and attach in
4499 extended-remote mode.
4501 * hppa*64*-*-hpux11* target broken
4502 The debugger is unable to start a program and fails with the following
4503 error: "Error trying to get information about dynamic linker".
4504 The gdb-6.7 release is also affected.
4506 * GDB now supports the --enable-targets= configure option to allow
4507 building a single GDB executable that supports multiple remote
4508 target architectures.
4510 * GDB now supports debugging C and C++ programs which use the
4511 Decimal Floating Point extension. In addition, the PowerPC target
4512 now has a set of pseudo-registers to inspect decimal float values
4513 stored in two consecutive float registers.
4515 * The -break-insert MI command can optionally create pending
4518 * Improved support for debugging Ada
4519 Many improvements to the Ada language support have been made. These
4521 - Better support for Ada2005 interface types
4522 - Improved handling of arrays and slices in general
4523 - Better support for Taft-amendment types
4524 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4526 - Improved command completion in Ada
4529 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4534 set print frame-arguments (all|scalars|none)
4535 show print frame-arguments
4536 The value of this variable can be changed to control which argument
4537 values should be printed by the debugger when displaying a frame.
4542 Transfer files to and from a remote target, and delete remote files.
4549 Transfer files to and from a remote target, and delete remote files.
4551 * New remote packets
4558 Open, close, read, write, and delete files on the remote system.
4561 Attach to an existing process on the remote system, in extended-remote
4565 Run a new process on the remote system, in extended-remote mode.
4567 *** Changes in GDB 6.7
4569 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4570 bfd, libiberty and opcodes, as revealed by static analysis donated by
4571 Coverity, Inc. (http://scan.coverity.com).
4573 * When looking up multiply-defined global symbols, GDB will now prefer the
4574 symbol definition in the current shared library if it was built using the
4575 -Bsymbolic linker option.
4577 * When the Text User Interface (TUI) is not configured, GDB will now
4578 recognize the -tui command-line option and print a message that the TUI
4581 * The GDB remote stub, gdbserver, now has lower overhead for high
4582 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4584 * GDB for MIPS targets now autodetects whether a remote target provides
4585 32-bit or 64-bit register values.
4587 * Support for C++ member pointers has been improved.
4589 * GDB now understands XML target descriptions, which specify the
4590 target's overall architecture. GDB can read a description from
4591 a local file or over the remote serial protocol.
4593 * Vectors of single-byte data use a new integer type which is not
4594 automatically displayed as character or string data.
4596 * The /s format now works with the print command. It displays
4597 arrays of single-byte integers and pointers to single-byte integers
4600 * Target descriptions can now describe target-specific registers,
4601 for architectures which have implemented the support (currently
4602 only ARM, M68K, and MIPS).
4604 * GDB and the GDB remote stub, gdbserver, now support the XScale
4607 * The GDB remote stub, gdbserver, has been updated to support
4608 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4609 has been rewritten to use the standard GDB remote protocol.
4611 * GDB can now step into C++ functions which are called through thunks.
4613 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4615 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4616 layout. It also supports a TextSeg= and DataSeg= response when only
4617 segment base addresses (rather than offsets) are available.
4619 * The /i format now outputs any trailing branch delay slot instructions
4620 immediately following the last instruction within the count specified.
4622 * The GDB remote protocol "T" stop reply packet now supports a
4623 "library" response. Combined with the new "qXfer:libraries:read"
4624 packet, this response allows GDB to debug shared libraries on targets
4625 where the operating system manages the list of loaded libraries (e.g.
4626 Windows and SymbianOS).
4628 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4629 (DLLs) on Windows and Windows CE targets.
4631 * GDB now supports a faster verification that a .debug file matches its binary
4632 according to its build-id signature, if the signature is present.
4638 Enable or disable hardware flow control (RTS/CTS) on the serial port
4639 when debugging using remote targets.
4641 set mem inaccessible-by-default
4642 show mem inaccessible-by-default
4643 If the target supplies a memory map, for instance via the remote
4644 protocol's "qXfer:memory-map:read" packet, setting this variable
4645 prevents GDB from accessing memory outside the memory map. This
4646 is useful for targets with memory mapped registers or which react
4647 badly to accesses of unmapped address space.
4649 set breakpoint auto-hw
4650 show breakpoint auto-hw
4651 If the target supplies a memory map, for instance via the remote
4652 protocol's "qXfer:memory-map:read" packet, setting this variable
4653 lets GDB use hardware breakpoints automatically for memory regions
4654 where it can not use software breakpoints. This covers both the
4655 "break" command and internal breakpoints used for other commands
4656 including "next" and "finish".
4659 catch exception unhandled
4660 Stop the program execution when Ada exceptions are raised.
4663 Stop the program execution when an Ada assertion failed.
4667 Set an alternate system root for target files. This is a more
4668 general version of "set solib-absolute-prefix", which is now
4669 an alias to "set sysroot".
4672 Provide extended SPU facility status information. This set of
4673 commands is available only when debugging the Cell/B.E. SPU
4676 * New native configurations
4678 OpenBSD/sh sh*-*openbsd*
4681 unset tdesc filename
4683 Use the specified local file as an XML target description, and do
4684 not query the target for its built-in description.
4688 OpenBSD/sh sh*-*-openbsd*
4689 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4690 Toshiba Media Processor mep-elf
4692 * New remote packets
4695 Ignore the specified signals; pass them directly to the debugged program
4696 without stopping other threads or reporting them to GDB.
4698 qXfer:features:read:
4699 Read an XML target description from the target, which describes its
4704 Read or write contents of an spufs file on the target system. These
4705 packets are available only on the Cell/B.E. SPU architecture.
4707 qXfer:libraries:read:
4708 Report the loaded shared libraries. Combined with new "T" packet
4709 response, this packet allows GDB to debug shared libraries on
4710 targets where the operating system manages the list of loaded
4711 libraries (e.g. Windows and SymbianOS).
4715 Support for these obsolete configurations has been removed.
4723 i[34567]86-*-lynxos*
4724 i[34567]86-*-netware*
4725 i[34567]86-*-sco3.2v5*
4726 i[34567]86-*-sco3.2v4*
4728 i[34567]86-*-sysv4.2*
4731 i[34567]86-*-unixware2*
4732 i[34567]86-*-unixware*
4741 * Other removed features
4748 Various m68k-only ROM monitors.
4755 Various Renesas ROM monitors and debugging interfaces for SH and
4760 Support for a Macraigor serial interface to on-chip debugging.
4761 GDB does not directly support the newer parallel or USB
4766 A debug information format. The predecessor to DWARF 2 and
4767 DWARF 3, which are still supported.
4769 Support for the HP aCC compiler on HP-UX/PA-RISC
4771 SOM-encapsulated symbolic debugging information, automatic
4772 invocation of pxdb, and the aCC custom C++ ABI. This does not
4773 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4774 with aCC can still be debugged on an assembly level.
4776 MIPS ".pdr" sections
4778 A MIPS-specific format used to describe stack frame layout
4779 in debugging information.
4783 GDB could work with an older version of Guile to debug
4784 the interpreter and Scheme programs running in it.
4786 set mips stack-arg-size
4787 set mips saved-gpreg-size
4789 Use "set mips abi" to control parameter passing for MIPS.
4791 *** Changes in GDB 6.6
4796 Cell Broadband Engine SPU spu-elf
4798 * GDB can now be configured as a cross-debugger targeting native Windows
4799 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4800 running on a Windows system over TCP/IP to debug Windows programs.
4802 * The GDB remote stub, gdbserver, has been updated to support Windows and
4803 Cygwin debugging. Both single-threaded and multi-threaded programs are
4806 * The "set trust-readonly-sections" command works again. This command was
4807 broken in GDB 6.3, 6.4, and 6.5.
4809 * The "load" command now supports writing to flash memory, if the remote
4810 stub provides the required support.
4812 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4813 longer requires symbolic debug information (e.g. DWARF-2).
4818 unset substitute-path
4819 show substitute-path
4820 Manage a list of substitution rules that GDB uses to rewrite the name
4821 of the directories where the sources are located. This can be useful
4822 for instance when the sources were moved to a different location
4823 between compilation and debugging.
4827 Print each CLI command as it is executed. Each command is prefixed with
4828 a number of `+' symbols representing the nesting depth.
4829 The source command now has a `-v' option to enable the same feature.
4833 The ARM Demon monitor support (RDP protocol, "target rdp").
4835 Kernel Object Display, an embedded debugging feature which only worked with
4836 an obsolete version of Cisco IOS.
4838 The 'set download-write-size' and 'show download-write-size' commands.
4840 * New remote packets
4843 Tell a stub about GDB client features, and request remote target features.
4844 The first feature implemented is PacketSize, which allows the target to
4845 specify the size of packets it can handle - to minimize the number of
4846 packets required and improve performance when connected to a remote
4850 Fetch an OS auxilliary vector from the remote stub. This packet is a
4851 more efficient replacement for qPart:auxv:read.
4853 qXfer:memory-map:read:
4854 Fetch a memory map from the remote stub, including information about
4855 RAM, ROM, and flash memory devices.
4860 Erase and program a flash memory device.
4862 * Removed remote packets
4865 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4866 used it, and only gdbserver implemented it.
4868 *** Changes in GDB 6.5
4872 Renesas M32C/M16C m32c-elf
4874 Morpho Technologies ms1 ms1-elf
4878 init-if-undefined Initialize a convenience variable, but
4879 only if it doesn't already have a value.
4881 The following commands are presently only implemented for native GNU/Linux:
4883 checkpoint Save a snapshot of the program state.
4885 restart <n> Return the program state to a
4886 previously saved state.
4888 info checkpoints List currently saved checkpoints.
4890 delete-checkpoint <n> Delete a previously saved checkpoint.
4892 set|show detach-on-fork Tell gdb whether to detach from a newly
4893 forked process, or to keep debugging it.
4895 info forks List forks of the user program that
4896 are available to be debugged.
4898 fork <n> Switch to debugging one of several
4899 forks of the user program that are
4900 available to be debugged.
4902 delete-fork <n> Delete a fork from the list of forks
4903 that are available to be debugged (and
4904 kill the forked process).
4906 detach-fork <n> Delete a fork from the list of forks
4907 that are available to be debugged (and
4908 allow the process to continue).
4912 Morpho Technologies ms2 ms1-elf
4914 * Improved Windows host support
4916 GDB now builds as a cross debugger hosted on i686-mingw32, including
4917 native console support, and remote communications using either
4918 network sockets or serial ports.
4920 * Improved Modula-2 language support
4922 GDB can now print most types in the Modula-2 syntax. This includes:
4923 basic types, set types, record types, enumerated types, range types,
4924 pointer types and ARRAY types. Procedure var parameters are correctly
4925 printed and hexadecimal addresses and character constants are also
4926 written in the Modula-2 syntax. Best results can be obtained by using
4927 GNU Modula-2 together with the -gdwarf-2 command line option.
4931 The ARM rdi-share module.
4933 The Netware NLM debug server.
4935 *** Changes in GDB 6.4
4937 * New native configurations
4939 OpenBSD/arm arm*-*-openbsd*
4940 OpenBSD/mips64 mips64-*-openbsd*
4944 Morpho Technologies ms1 ms1-elf
4946 * New command line options
4948 --batch-silent As for --batch, but totally silent.
4949 --return-child-result The debugger will exist with the same value
4950 the child (debugged) program exited with.
4951 --eval-command COMMAND, -ex COMMAND
4952 Execute a single GDB CLI command. This may be
4953 specified multiple times and in conjunction
4954 with the --command (-x) option.
4956 * Deprecated commands removed
4958 The following commands, that were deprecated in 2000, have been
4962 set|show arm disassembly-flavor set|show arm disassembler
4963 othernames set arm disassembler
4964 set|show remotedebug set|show debug remote
4965 set|show archdebug set|show debug arch
4966 set|show eventdebug set|show debug event
4969 * New BSD user-level threads support
4971 It is now possible to debug programs using the user-level threads
4972 library on OpenBSD and FreeBSD. Currently supported (target)
4975 FreeBSD/amd64 x86_64-*-freebsd*
4976 FreeBSD/i386 i386-*-freebsd*
4977 OpenBSD/i386 i386-*-openbsd*
4979 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4980 are not yet supported.
4982 * New support for Matsushita MN10300 w/sim added
4983 (Work in progress). mn10300-elf.
4985 * REMOVED configurations and files
4987 VxWorks and the XDR protocol *-*-vxworks
4988 Motorola MCORE mcore-*-*
4989 National Semiconductor NS32000 ns32k-*-*
4991 * New "set print array-indexes" command
4993 After turning this setting "on", GDB prints the index of each element
4994 when displaying arrays. The default is "off" to preserve the previous
4997 * VAX floating point support
4999 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5001 * User-defined command support
5003 In addition to using $arg0..$arg9 for argument passing, it is now possible
5004 to use $argc to determine now many arguments have been passed. See the
5005 section on user-defined commands in the user manual for more information.
5007 *** Changes in GDB 6.3:
5009 * New command line option
5011 GDB now accepts -l followed by a number to set the timeout for remote
5014 * GDB works with GCC -feliminate-dwarf2-dups
5016 GDB now supports a more compact representation of DWARF-2 debug
5017 information using DW_FORM_ref_addr references. These are produced
5018 by GCC with the option -feliminate-dwarf2-dups and also by some
5019 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5020 to use -feliminate-dwarf2-dups.
5022 * Internationalization
5024 When supported by the host system, GDB will be built with
5025 internationalization (libintl). The task of marking up the sources is
5026 continued, we're looking forward to our first translation.
5030 Initial support for debugging programs compiled with the GNAT
5031 implementation of the Ada programming language has been integrated
5032 into GDB. In this release, support is limited to expression evaluation.
5034 * New native configurations
5036 GNU/Linux/m32r m32r-*-linux-gnu
5040 GDB's remote protocol now includes support for the 'p' packet. This
5041 packet is used to fetch individual registers from a remote inferior.
5043 * END-OF-LIFE registers[] compatibility module
5045 GDB's internal register infrastructure has been completely rewritten.
5046 The new infrastructure making possible the implementation of key new
5047 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5050 GDB 6.3 will be the last release to include the the registers[]
5051 compatibility module that allowed out-of-date configurations to
5052 continue to work. This change directly impacts the following
5062 powerpc bdm protocol
5064 Unless there is activity to revive these configurations, they will be
5065 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5067 * OBSOLETE configurations and files
5069 Configurations that have been declared obsolete in this release have
5070 been commented out. Unless there is activity to revive these
5071 configurations, the next release of GDB will have their sources
5072 permanently REMOVED.
5081 *** Changes in GDB 6.2.1:
5083 * MIPS `break main; run' gave an heuristic-fence-post warning
5085 When attempting to run even a simple program, a warning about
5086 heuristic-fence-post being hit would be reported. This problem has
5089 * MIPS IRIX 'long double' crashed GDB
5091 When examining a long double variable, GDB would get a segmentation
5092 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5093 IRIX long double values).
5097 A bug in the VAX stack code was causing problems with the "next"
5098 command. This problem has been fixed.
5100 *** Changes in GDB 6.2:
5102 * Fix for ``many threads''
5104 On GNU/Linux systems that use the NPTL threads library, a program
5105 rapidly creating and deleting threads would confuse GDB leading to the
5108 ptrace: No such process.
5109 thread_db_get_info: cannot get thread info: generic error
5111 This problem has been fixed.
5113 * "-async" and "-noasync" options removed.
5115 Support for the broken "-noasync" option has been removed (it caused
5118 * New ``start'' command.
5120 This command runs the program until the begining of the main procedure.
5122 * New BSD Kernel Data Access Library (libkvm) interface
5124 Using ``target kvm'' it is now possible to debug kernel core dumps and
5125 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5126 platforms. Currently supported (native-only) configurations are:
5128 FreeBSD/amd64 x86_64-*-freebsd*
5129 FreeBSD/i386 i?86-*-freebsd*
5130 NetBSD/i386 i?86-*-netbsd*
5131 NetBSD/m68k m68*-*-netbsd*
5132 NetBSD/sparc sparc-*-netbsd*
5133 OpenBSD/amd64 x86_64-*-openbsd*
5134 OpenBSD/i386 i?86-*-openbsd*
5135 OpenBSD/m68k m68*-openbsd*
5136 OpenBSD/sparc sparc-*-openbsd*
5138 * Signal trampoline code overhauled
5140 Many generic problems with GDB's signal handling code have been fixed.
5141 These include: backtraces through non-contiguous stacks; recognition
5142 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5143 call; backtrace through a signal trampoline; step into and out of
5144 signal handlers; and single-stepping in the signal trampoline.
5146 Please note that kernel bugs are a limiting factor here. These
5147 features have been shown to work on an s390 GNU/Linux system that
5148 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5150 * Cygwin support for DWARF 2 added.
5152 * New native configurations
5154 GNU/Linux/hppa hppa*-*-linux*
5155 OpenBSD/hppa hppa*-*-openbsd*
5156 OpenBSD/m68k m68*-*-openbsd*
5157 OpenBSD/m88k m88*-*-openbsd*
5158 OpenBSD/powerpc powerpc-*-openbsd*
5159 NetBSD/vax vax-*-netbsd*
5160 OpenBSD/vax vax-*-openbsd*
5162 * END-OF-LIFE frame compatibility module
5164 GDB's internal frame infrastructure has been completely rewritten.
5165 The new infrastructure making it possible to support key new features
5166 including DWARF 2 Call Frame Information. To aid in the task of
5167 migrating old configurations to this new infrastructure, a
5168 compatibility module, that allowed old configurations to continue to
5169 work, was also included.
5171 GDB 6.2 will be the last release to include this frame compatibility
5172 module. This change directly impacts the following configurations:
5182 Unless there is activity to revive these configurations, they will be
5183 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5185 * REMOVED configurations and files
5187 Sun 3, running SunOS 3 m68*-*-sunos3*
5188 Sun 3, running SunOS 4 m68*-*-sunos4*
5189 Sun 2, running SunOS 3 m68000-*-sunos3*
5190 Sun 2, running SunOS 4 m68000-*-sunos4*
5191 Motorola 680x0 running LynxOS m68*-*-lynxos*
5192 AT&T 3b1/Unix pc m68*-att-*
5193 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5194 decstation mips-dec-* mips-little-*
5195 riscos mips-*-riscos* mips-*-sysv*
5196 sonymips mips-sony-*
5197 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5199 *** Changes in GDB 6.1.1:
5201 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5203 The TUI (Text-mode User Interface) is now built as part of a default
5204 GDB configuration. It is enabled by either selecting the TUI with the
5205 command line option "-i=tui" or by running the separate "gdbtui"
5206 program. For more information on the TUI, see the manual "Debugging
5209 * Pending breakpoint support (also included in GDB 6.1)
5211 Support has been added to allow you to specify breakpoints in shared
5212 libraries that have not yet been loaded. If a breakpoint location
5213 cannot be found, and the "breakpoint pending" option is set to auto,
5214 GDB queries you if you wish to make the breakpoint pending on a future
5215 shared-library load. If and when GDB resolves the breakpoint symbol,
5216 the pending breakpoint is removed as one or more regular breakpoints
5219 Pending breakpoints are very useful for GCJ Java debugging.
5221 * Fixed ISO-C build problems
5223 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5224 non ISO-C code that stopped them being built using a more strict ISO-C
5225 compiler (e.g., IBM's C compiler).
5227 * Fixed build problem on IRIX 5
5229 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5230 wasn't able to compile compile on an IRIX 5 system.
5232 * Added execute permission to gdb/gdbserver/configure
5234 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5235 permission. This bug would cause configure to fail on a number of
5236 systems (Solaris, IRIX). Ref: server/519.
5238 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5240 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5241 has been updated to use constant array sizes.
5243 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5245 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5246 its generated DWARF Call Frame Info. This encoding was causing GDB to
5247 panic, that panic has been fixed. Ref: gdb/1628.
5249 * Fixed a problem when examining parameters in shared library code.
5251 When examining parameters in optimized shared library code generated
5252 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5253 not available''. GDB now correctly displays the variable's value.
5255 *** Changes in GDB 6.1:
5257 * Removed --with-mmalloc
5259 Support for the mmalloc memory manager has been removed, as it
5260 conflicted with the internal gdb byte cache.
5262 * Changes in AMD64 configurations
5264 The AMD64 target now includes the %cs and %ss registers. As a result
5265 the AMD64 remote protocol has changed; this affects the floating-point
5266 and SSE registers. If you rely on those registers for your debugging,
5267 you should upgrade gdbserver on the remote side.
5269 * Revised SPARC target
5271 The SPARC target has been completely revised, incorporating the
5272 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5273 support for LynxOS and SunOS 4 has been dropped. Calling functions
5274 from within GDB on operating systems with a non-executable stack
5275 (Solaris, OpenBSD) now works.
5279 GDB has a new C++ demangler which does a better job on the mangled
5280 names generated by current versions of g++. It also runs faster, so
5281 with this and other changes gdb should now start faster on large C++
5284 * DWARF 2 Location Expressions
5286 GDB support for location expressions has been extended to support function
5287 arguments and frame bases. Older versions of GDB could crash when they
5290 * C++ nested types and namespaces
5292 GDB's support for nested types and namespaces in C++ has been
5293 improved, especially if you use the DWARF 2 debugging format. (This
5294 is the default for recent versions of GCC on most platforms.)
5295 Specifically, if you have a class "Inner" defined within a class or
5296 namespace "Outer", then GDB realizes that the class's name is
5297 "Outer::Inner", not simply "Inner". This should greatly reduce the
5298 frequency of complaints about not finding RTTI symbols. In addition,
5299 if you are stopped at inside of a function defined within a namespace,
5300 GDB modifies its name lookup accordingly.
5302 * New native configurations
5304 NetBSD/amd64 x86_64-*-netbsd*
5305 OpenBSD/amd64 x86_64-*-openbsd*
5306 OpenBSD/alpha alpha*-*-openbsd*
5307 OpenBSD/sparc sparc-*-openbsd*
5308 OpenBSD/sparc64 sparc64-*-openbsd*
5310 * New debugging protocols
5312 M32R with SDI protocol m32r-*-elf*
5314 * "set prompt-escape-char" command deleted.
5316 The command "set prompt-escape-char" has been deleted. This command,
5317 and its very obscure effet on GDB's prompt, was never documented,
5318 tested, nor mentioned in the NEWS file.
5320 * OBSOLETE configurations and files
5322 Configurations that have been declared obsolete in this release have
5323 been commented out. Unless there is activity to revive these
5324 configurations, the next release of GDB will have their sources
5325 permanently REMOVED.
5327 Sun 3, running SunOS 3 m68*-*-sunos3*
5328 Sun 3, running SunOS 4 m68*-*-sunos4*
5329 Sun 2, running SunOS 3 m68000-*-sunos3*
5330 Sun 2, running SunOS 4 m68000-*-sunos4*
5331 Motorola 680x0 running LynxOS m68*-*-lynxos*
5332 AT&T 3b1/Unix pc m68*-att-*
5333 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5334 decstation mips-dec-* mips-little-*
5335 riscos mips-*-riscos* mips-*-sysv*
5336 sonymips mips-sony-*
5337 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5339 * REMOVED configurations and files
5341 SGI Irix-4.x mips-sgi-irix4 or iris4
5342 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5343 Z8000 simulator z8k-zilog-none or z8ksim
5344 Matsushita MN10200 w/simulator mn10200-*-*
5345 H8/500 simulator h8500-hitachi-hms or h8500hms
5346 HP/PA running BSD hppa*-*-bsd*
5347 HP/PA running OSF/1 hppa*-*-osf*
5348 HP/PA Pro target hppa*-*-pro*
5349 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5350 386BSD i[3456]86-*-bsd*
5351 Sequent family i[3456]86-sequent-sysv4*
5352 i[3456]86-sequent-sysv*
5353 i[3456]86-sequent-bsd*
5354 SPARC running LynxOS sparc-*-lynxos*
5355 SPARC running SunOS 4 sparc-*-sunos4*
5356 Tsqware Sparclet sparclet-*-*
5357 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5359 *** Changes in GDB 6.0:
5363 Support for debugging the Objective-C programming language has been
5364 integrated into GDB.
5366 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5368 DWARF 2's Call Frame Information makes available compiler generated
5369 information that more exactly describes the program's run-time stack.
5370 By using this information, GDB is able to provide more robust stack
5373 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5374 have been updated to use a new backtrace mechanism which includes
5375 DWARF 2 CFI support.
5379 GDB's remote protocol has been extended to include support for hosted
5380 file I/O (where the remote target uses GDB's file system). See GDB's
5381 remote protocol documentation for details.
5383 * All targets using the new architecture framework.
5385 All of GDB's targets have been updated to use the new internal
5386 architecture framework. The way is now open for future GDB releases
5387 to include cross-architecture native debugging support (i386 on amd64,
5390 * GNU/Linux's Thread Local Storage (TLS)
5392 GDB now includes support for for the GNU/Linux implementation of
5393 per-thread variables.
5395 * GNU/Linux's Native POSIX Thread Library (NPTL)
5397 GDB's thread code has been updated to work with either the new
5398 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5400 * Separate debug info.
5402 GDB, in conjunction with BINUTILS, now supports a mechanism for
5403 automatically loading debug information from a separate file. Instead
5404 of shipping full debug and non-debug versions of system libraries,
5405 system integrators can now instead ship just the stripped libraries
5406 and optional debug files.
5408 * DWARF 2 Location Expressions
5410 DWARF 2 Location Expressions allow the compiler to more completely
5411 describe the location of variables (even in optimized code) to the
5414 GDB now includes preliminary support for location expressions (support
5415 for DW_OP_piece is still missing).
5419 A number of long standing bugs that caused GDB to die while starting a
5420 Java application have been fixed. GDB's Java support is now
5421 considered "useable".
5423 * GNU/Linux support for fork, vfork, and exec.
5425 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5426 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5429 * GDB supports logging output to a file
5431 There are two new commands, "set logging" and "show logging", which can be
5432 used to capture GDB's output to a file.
5434 * The meaning of "detach" has changed for gdbserver
5436 The "detach" command will now resume the application, as documented. To
5437 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5440 * d10v, m68hc11 `regs' command deprecated
5442 The `info registers' command has been updated so that it displays the
5443 registers using a format identical to the old `regs' command.
5447 A new command, "maint set profile on/off", has been added. This command can
5448 be used to enable or disable profiling while running GDB, to profile a
5449 session or a set of commands. In addition there is a new configure switch,
5450 "--enable-profiling", which will cause GDB to be compiled with profiling
5451 data, for more informative profiling results.
5453 * Default MI syntax changed to "mi2".
5455 The default MI (machine interface) syntax, enabled by the command line
5456 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5457 "mi1", can be enabled by specifying the option "-i=mi1".
5459 Support for the original "mi0" syntax (included in GDB 5.0) has been
5462 Fix for gdb/192: removed extraneous space when displaying frame level.
5463 Fix for gdb/672: update changelist is now output in mi list format.
5464 Fix for gdb/702: a -var-assign that updates the value now shows up
5465 in a subsequent -var-update.
5467 * New native configurations.
5469 FreeBSD/amd64 x86_64-*-freebsd*
5471 * Multi-arched targets.
5473 HP/PA HPUX11 hppa*-*-hpux*
5474 Renesas M32R/D w/simulator m32r-*-elf*
5476 * OBSOLETE configurations and files
5478 Configurations that have been declared obsolete in this release have
5479 been commented out. Unless there is activity to revive these
5480 configurations, the next release of GDB will have their sources
5481 permanently REMOVED.
5483 Z8000 simulator z8k-zilog-none or z8ksim
5484 Matsushita MN10200 w/simulator mn10200-*-*
5485 H8/500 simulator h8500-hitachi-hms or h8500hms
5486 HP/PA running BSD hppa*-*-bsd*
5487 HP/PA running OSF/1 hppa*-*-osf*
5488 HP/PA Pro target hppa*-*-pro*
5489 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5490 Sequent family i[3456]86-sequent-sysv4*
5491 i[3456]86-sequent-sysv*
5492 i[3456]86-sequent-bsd*
5493 Tsqware Sparclet sparclet-*-*
5494 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5496 * REMOVED configurations and files
5499 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5500 IBM AIX PS/2 i[3456]86-*-aix
5501 i386 running Mach 3.0 i[3456]86-*-mach3*
5502 i386 running Mach i[3456]86-*-mach*
5503 i386 running OSF/1 i[3456]86-*osf1mk*
5504 HP/Apollo 68k Family m68*-apollo*-sysv*,
5506 m68*-hp-bsd*, m68*-hp-hpux*
5507 Argonaut Risc Chip (ARC) arc-*-*
5508 Mitsubishi D30V d30v-*-*
5509 Fujitsu FR30 fr30-*-elf*
5510 OS/9000 i[34]86-*-os9k
5511 I960 with MON960 i960-*-coff
5513 * MIPS $fp behavior changed
5515 The convenience variable $fp, for the MIPS, now consistently returns
5516 the address of the current frame's base. Previously, depending on the
5517 context, $fp could refer to either $sp or the current frame's base
5518 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5519 The GNU Source-Level Debugger''.
5521 *** Changes in GDB 5.3:
5523 * GNU/Linux shared library multi-threaded performance improved.
5525 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5526 `/proc', in preference to `ptrace' for memory reads. This may result
5527 in an improvement in the start-up time of multi-threaded, shared
5528 library applications when run under GDB. One GDB user writes: ``loads
5529 shared libs like mad''.
5531 * ``gdbserver'' now supports multi-threaded applications on some targets
5533 Support for debugging multi-threaded applications which use
5534 the GNU/Linux LinuxThreads package has been added for
5535 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5536 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5538 * GDB now supports C/C++ preprocessor macros.
5540 GDB now expands preprocessor macro invocations in C/C++ expressions,
5541 and provides various commands for showing macro definitions and how
5544 The new command `macro expand EXPRESSION' expands any macro
5545 invocations in expression, and shows the result.
5547 The new command `show macro MACRO-NAME' shows the definition of the
5548 macro named MACRO-NAME, and where it was defined.
5550 Most compilers don't include information about macros in the debugging
5551 information by default. In GCC 3.1, for example, you need to compile
5552 your program with the options `-gdwarf-2 -g3'. If the macro
5553 information is present in the executable, GDB will read it.
5555 * Multi-arched targets.
5557 DEC Alpha (partial) alpha*-*-*
5558 DEC VAX (partial) vax-*-*
5560 National Semiconductor NS32000 (partial) ns32k-*-*
5561 Motorola 68000 (partial) m68k-*-*
5562 Motorola MCORE mcore-*-*
5566 Fujitsu FRV architecture added by Red Hat frv*-*-*
5569 * New native configurations
5571 Alpha NetBSD alpha*-*-netbsd*
5572 SH NetBSD sh*-*-netbsdelf*
5573 MIPS NetBSD mips*-*-netbsd*
5574 UltraSPARC NetBSD sparc64-*-netbsd*
5576 * OBSOLETE configurations and files
5578 Configurations that have been declared obsolete in this release have
5579 been commented out. Unless there is activity to revive these
5580 configurations, the next release of GDB will have their sources
5581 permanently REMOVED.
5583 Mitsubishi D30V d30v-*-*
5584 OS/9000 i[34]86-*-os9k
5585 IBM AIX PS/2 i[3456]86-*-aix
5586 Fujitsu FR30 fr30-*-elf*
5587 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5588 Argonaut Risc Chip (ARC) arc-*-*
5589 i386 running Mach 3.0 i[3456]86-*-mach3*
5590 i386 running Mach i[3456]86-*-mach*
5591 i386 running OSF/1 i[3456]86-*osf1mk*
5592 HP/Apollo 68k Family m68*-apollo*-sysv*,
5594 m68*-hp-bsd*, m68*-hp-hpux*
5595 I960 with MON960 i960-*-coff
5597 * OBSOLETE languages
5599 CHILL, a Pascal like language used by telecommunications companies.
5601 * REMOVED configurations and files
5603 AMD 29k family via UDI a29k-amd-udi, udi29k
5604 A29K VxWorks a29k-*-vxworks
5605 AMD 29000 embedded, using EBMON a29k-none-none
5606 AMD 29000 embedded with COFF a29k-none-coff
5607 AMD 29000 embedded with a.out a29k-none-aout
5609 testsuite/gdb.hp/gdb.threads-hp/ directory
5611 * New command "set max-user-call-depth <nnn>"
5613 This command allows the user to limit the call depth of user-defined
5614 commands. The default is 1024.
5616 * Changes in FreeBSD/i386 native debugging.
5618 Support for the "generate-core-file" has been added.
5620 * New commands "dump", "append", and "restore".
5622 These commands allow data to be copied from target memory
5623 to a bfd-format or binary file (dump and append), and back
5624 from a file into memory (restore).
5626 * Improved "next/step" support on multi-processor Alpha Tru64.
5628 The previous single-step mechanism could cause unpredictable problems,
5629 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5630 of a software single-step mechanism prevents this.
5632 *** Changes in GDB 5.2.1:
5640 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5641 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5642 Fix, by Joel Brobecker imported from mainline.
5644 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5645 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5646 Fix, by Fred Fish, imported from mainline.
5648 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5649 Surprisingly enough, it works now.
5650 By Michal Ludvig, imported from mainline.
5652 i386 hardware watchpoint support:
5653 avoid misses on second run for some targets.
5654 By Pierre Muller, imported from mainline.
5656 *** Changes in GDB 5.2:
5658 * New command "set trust-readonly-sections on[off]".
5660 This command is a hint that tells gdb that read-only sections
5661 really are read-only (ie. that their contents will not change).
5662 In this mode, gdb will go to the object file rather than the
5663 target to read memory from read-only sections (such as ".text").
5664 This can be a significant performance improvement on some
5665 (notably embedded) targets.
5667 * New command "generate-core-file" (or "gcore").
5669 This new gdb command allows the user to drop a core file of the child
5670 process state at any time. So far it's been implemented only for
5671 GNU/Linux and Solaris, but should be relatively easily ported to other
5672 hosts. Argument is core file name (defaults to core.<pid>).
5674 * New command line option
5676 GDB now accepts --pid or -p followed by a process id.
5678 * Change in command line behavior -- corefiles vs. process ids.
5680 There is a subtle behavior in the way in which GDB handles
5681 command line arguments. The first non-flag argument is always
5682 a program to debug, but the second non-flag argument may either
5683 be a corefile or a process id. Previously, GDB would attempt to
5684 open the second argument as a corefile, and if that failed, would
5685 issue a superfluous error message and then attempt to attach it as
5686 a process. Now, if the second argument begins with a non-digit,
5687 it will be treated as a corefile. If it begins with a digit,
5688 GDB will attempt to attach it as a process, and if no such process
5689 is found, will then attempt to open it as a corefile.
5691 * Changes in ARM configurations.
5693 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5694 configuration is fully multi-arch.
5696 * New native configurations
5698 ARM NetBSD arm*-*-netbsd*
5699 x86 OpenBSD i[3456]86-*-openbsd*
5700 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5701 Sparc64 running FreeBSD sparc64-*-freebsd*
5705 Sanyo XStormy16 xstormy16-elf
5707 * OBSOLETE configurations and files
5709 Configurations that have been declared obsolete in this release have
5710 been commented out. Unless there is activity to revive these
5711 configurations, the next release of GDB will have their sources
5712 permanently REMOVED.
5714 AMD 29k family via UDI a29k-amd-udi, udi29k
5715 A29K VxWorks a29k-*-vxworks
5716 AMD 29000 embedded, using EBMON a29k-none-none
5717 AMD 29000 embedded with COFF a29k-none-coff
5718 AMD 29000 embedded with a.out a29k-none-aout
5720 testsuite/gdb.hp/gdb.threads-hp/ directory
5722 * REMOVED configurations and files
5724 TI TMS320C80 tic80-*-*
5726 PowerPC Solaris powerpcle-*-solaris*
5727 PowerPC Windows NT powerpcle-*-cygwin32
5728 PowerPC Netware powerpc-*-netware*
5729 Harris/CXUX m88k m88*-harris-cxux*
5730 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5731 ns32k-utek-sysv* ns32k-utek-*
5732 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5733 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5734 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5735 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5736 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5738 * Changes to command line processing
5740 The new `--args' feature can be used to specify command-line arguments
5741 for the inferior from gdb's command line.
5743 * Changes to key bindings
5745 There is a new `operate-and-get-next' function bound to `C-o'.
5747 *** Changes in GDB 5.1.1
5749 Fix compile problem on DJGPP.
5751 Fix a problem with floating-point registers on the i386 being
5754 Fix to stop GDB crashing on .debug_str debug info.
5756 Numerous documentation fixes.
5758 Numerous testsuite fixes.
5760 *** Changes in GDB 5.1:
5762 * New native configurations
5764 Alpha FreeBSD alpha*-*-freebsd*
5765 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5766 MIPS GNU/Linux mips*-*-linux*
5767 MIPS SGI Irix 6.x mips*-sgi-irix6*
5768 ia64 AIX ia64-*-aix*
5769 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5773 Motorola 68HC11 and 68HC12 m68hc11-elf
5775 UltraSparc running GNU/Linux sparc64-*-linux*
5777 * OBSOLETE configurations and files
5779 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5780 Harris/CXUX m88k m88*-harris-cxux*
5781 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5782 ns32k-utek-sysv* ns32k-utek-*
5783 TI TMS320C80 tic80-*-*
5785 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5786 PowerPC Solaris powerpcle-*-solaris*
5787 PowerPC Windows NT powerpcle-*-cygwin32
5788 PowerPC Netware powerpc-*-netware*
5789 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5790 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5791 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5792 Apple Macintosh (MPW) host N/A
5794 stuff.c (Program to stuff files into a specially prepared space in kdb)
5795 kdb-start.c (Main loop for the standalone kernel debugger)
5797 Configurations that have been declared obsolete in this release have
5798 been commented out. Unless there is activity to revive these
5799 configurations, the next release of GDB will have their sources
5800 permanently REMOVED.
5802 * REMOVED configurations and files
5804 Altos 3068 m68*-altos-*
5805 Convex c1-*-*, c2-*-*
5807 ARM RISCix arm-*-* (as host)
5811 * GDB has been converted to ISO C.
5813 GDB's source code has been converted to ISO C. In particular, the
5814 sources are fully protoized, and rely on standard headers being
5819 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5821 * The MI enabled by default.
5823 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5824 revised and enabled by default. Packages which use GDB as a debugging
5825 engine behind a UI or another front end are encouraged to switch to
5826 using the GDB/MI interface, instead of the old annotations interface
5827 which is now deprecated.
5829 * Support for debugging Pascal programs.
5831 GDB now includes support for debugging Pascal programs. The following
5832 main features are supported:
5834 - Pascal-specific data types such as sets;
5836 - automatic recognition of Pascal sources based on file-name
5839 - Pascal-style display of data types, variables, and functions;
5841 - a Pascal expression parser.
5843 However, some important features are not yet supported.
5845 - Pascal string operations are not supported at all;
5847 - there are some problems with boolean types;
5849 - Pascal type hexadecimal constants are not supported
5850 because they conflict with the internal variables format;
5852 - support for Pascal objects and classes is not full yet;
5854 - unlike Pascal, GDB is case-sensitive for symbol names.
5856 * Changes in completion.
5858 Commands such as `shell', `run' and `set args', which pass arguments
5859 to inferior programs, now complete on file names, similar to what
5860 users expect at the shell prompt.
5862 Commands which accept locations, such as `disassemble', `print',
5863 `breakpoint', `until', etc. now complete on filenames as well as
5864 program symbols. Thus, if you type "break foob TAB", and the source
5865 files linked into the programs include `foobar.c', that file name will
5866 be one of the candidates for completion. However, file names are not
5867 considered for completion after you typed a colon that delimits a file
5868 name from a name of a function in that file, as in "break foo.c:bar".
5870 `set demangle-style' completes on available demangling styles.
5872 * New platform-independent commands:
5874 It is now possible to define a post-hook for a command as well as a
5875 hook that runs before the command. For more details, see the
5876 documentation of `hookpost' in the GDB manual.
5878 * Changes in GNU/Linux native debugging.
5880 Support for debugging multi-threaded programs has been completely
5881 revised for all platforms except m68k and sparc. You can now debug as
5882 many threads as your system allows you to have.
5884 Attach/detach is supported for multi-threaded programs.
5886 Support for SSE registers was added for x86. This doesn't work for
5887 multi-threaded programs though.
5889 * Changes in MIPS configurations.
5891 Multi-arch support is enabled for all MIPS configurations.
5893 GDB can now be built as native debugger on SGI Irix 6.x systems for
5894 debugging n32 executables. (Debugging 64-bit executables is not yet
5897 * Unified support for hardware watchpoints in all x86 configurations.
5899 Most (if not all) native x86 configurations support hardware-assisted
5900 breakpoints and watchpoints in a unified manner. This support
5901 implements debug register sharing between watchpoints, which allows to
5902 put a virtually infinite number of watchpoints on the same address,
5903 and also supports watching regions up to 16 bytes with several debug
5906 The new maintenance command `maintenance show-debug-regs' toggles
5907 debugging print-outs in functions that insert, remove, and test
5908 watchpoints and hardware breakpoints.
5910 * Changes in the DJGPP native configuration.
5912 New command ``info dos sysinfo'' displays assorted information about
5913 the CPU, OS, memory, and DPMI server.
5915 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5916 display information about segment descriptors stored in GDT, LDT, and
5919 New commands ``info dos pde'' and ``info dos pte'' display entries
5920 from Page Directory and Page Tables (for now works with CWSDPMI only).
5921 New command ``info dos address-pte'' displays the Page Table entry for
5922 a given linear address.
5924 GDB can now pass command lines longer than 126 characters to the
5925 program being debugged (requires an update to the libdbg.a library
5926 which is part of the DJGPP development kit).
5928 DWARF2 debug info is now supported.
5930 It is now possible to `step' and `next' through calls to `longjmp'.
5932 * Changes in documentation.
5934 All GDB documentation was converted to GFDL, the GNU Free
5935 Documentation License.
5937 Tracepoints-related commands are now fully documented in the GDB
5940 TUI, the Text-mode User Interface, is now documented in the manual.
5942 Tracepoints-related commands are now fully documented in the GDB
5945 The "GDB Internals" manual now has an index. It also includes
5946 documentation of `ui_out' functions, GDB coding standards, x86
5947 hardware watchpoints, and memory region attributes.
5949 * GDB's version number moved to ``version.in''
5951 The Makefile variable VERSION has been replaced by the file
5952 ``version.in''. People creating GDB distributions should update the
5953 contents of this file.
5957 GUD support is now a standard part of the EMACS distribution.
5959 *** Changes in GDB 5.0:
5961 * Improved support for debugging FP programs on x86 targets
5963 Unified and much-improved support for debugging floating-point
5964 programs on all x86 targets. In particular, ``info float'' now
5965 displays the FP registers in the same format on all x86 targets, with
5966 greater level of detail.
5968 * Improvements and bugfixes in hardware-assisted watchpoints
5970 It is now possible to watch array elements, struct members, and
5971 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5972 on x86 targets no longer erroneously trigger when the address is
5975 * Improvements in the native DJGPP version of GDB
5977 The distribution now includes all the scripts and auxiliary files
5978 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5979 machines ``out of the box''.
5981 The DJGPP version can now debug programs that use signals. It is
5982 possible to catch signals that happened in the debuggee, deliver
5983 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5984 would kill the program being debugged.) Programs that hook hardware
5985 interrupts (keyboard, timer, etc.) can also be debugged.
5987 It is now possible to debug DJGPP programs that redirect their
5988 standard handles or switch them to raw (as opposed to cooked) mode, or
5989 even close them. The command ``run < foo > bar'' works as expected,
5990 and ``info terminal'' reports useful information about the debuggee's
5991 terminal, including raw/cooked mode, redirection, etc.
5993 The DJGPP version now uses termios functions for console I/O, which
5994 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5997 DOS-style file names with drive letters are now fully supported by
6000 It is now possible to debug DJGPP programs that switch their working
6001 directory. It is also possible to rerun the debuggee any number of
6002 times without restarting GDB; thus, you can use the same setup,
6003 breakpoints, etc. for many debugging sessions.
6005 * New native configurations
6007 ARM GNU/Linux arm*-*-linux*
6008 PowerPC GNU/Linux powerpc-*-linux*
6012 Motorola MCore mcore-*-*
6013 x86 VxWorks i[3456]86-*-vxworks*
6014 PowerPC VxWorks powerpc-*-vxworks*
6015 TI TMS320C80 tic80-*-*
6017 * OBSOLETE configurations
6019 Altos 3068 m68*-altos-*
6020 Convex c1-*-*, c2-*-*
6022 ARM RISCix arm-*-* (as host)
6025 Configurations that have been declared obsolete will be commented out,
6026 but the code will be left in place. If there is no activity to revive
6027 these configurations before the next release of GDB, the sources will
6028 be permanently REMOVED.
6030 * Gould support removed
6032 Support for the Gould PowerNode and NP1 has been removed.
6034 * New features for SVR4
6036 On SVR4 native platforms (such as Solaris), if you attach to a process
6037 without first loading a symbol file, GDB will now attempt to locate and
6038 load symbols from the running process's executable file.
6040 * Many C++ enhancements
6042 C++ support has been greatly improved. Overload resolution now works properly
6043 in almost all cases. RTTI support is on the way.
6045 * Remote targets can connect to a sub-program
6047 A popen(3) style serial-device has been added. This device starts a
6048 sub-process (such as a stand-alone simulator) and then communicates
6049 with that. The sub-program to run is specified using the syntax
6050 ``|<program> <args>'' vis:
6052 (gdb) set remotedebug 1
6053 (gdb) target extended-remote |mn10300-elf-sim program-args
6055 * MIPS 64 remote protocol
6057 A long standing bug in the mips64 remote protocol where by GDB
6058 expected certain 32 bit registers (ex SR) to be transfered as 32
6059 instead of 64 bits has been fixed.
6061 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6062 added to provide backward compatibility with older versions of GDB.
6064 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6066 The command ``set remotebinarydownload'' command has been replaced by
6067 ``set remote X-packet''. Other commands in ``set remote'' family
6068 include ``set remote P-packet''.
6070 * Breakpoint commands accept ranges.
6072 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6073 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6074 ``tracepoint passcount'' also accepts a range of tracepoints.
6076 * ``apropos'' command added.
6078 The ``apropos'' command searches through command names and
6079 documentation strings, printing out matches, making it much easier to
6080 try to find a command that does what you are looking for.
6084 A new machine oriented interface (MI) has been added to GDB. This
6085 interface is designed for debug environments running GDB as a separate
6086 process. This is part of the long term libGDB project. See the
6087 "GDB/MI" chapter of the GDB manual for further information. It can be
6088 enabled by configuring with:
6090 .../configure --enable-gdbmi
6092 *** Changes in GDB-4.18:
6094 * New native configurations
6096 HP-UX 10.20 hppa*-*-hpux10.20
6097 HP-UX 11.x hppa*-*-hpux11.0*
6098 M68K GNU/Linux m68*-*-linux*
6102 Fujitsu FR30 fr30-*-elf*
6103 Intel StrongARM strongarm-*-*
6104 Mitsubishi D30V d30v-*-*
6106 * OBSOLETE configurations
6108 Gould PowerNode, NP1 np1-*-*, pn-*-*
6110 Configurations that have been declared obsolete will be commented out,
6111 but the code will be left in place. If there is no activity to revive
6112 these configurations before the next release of GDB, the sources will
6113 be permanently REMOVED.
6117 As a compatibility experiment, GDB's source files buildsym.h and
6118 buildsym.c have been converted to pure standard C, no longer
6119 containing any K&R compatibility code. We believe that all systems in
6120 use today either come with a standard C compiler, or have a GCC port
6121 available. If this is not true, please report the affected
6122 configuration to bug-gdb@gnu.org immediately. See the README file for
6123 information about getting a standard C compiler if you don't have one
6128 GDB now uses readline 2.2.
6130 * set extension-language
6132 You can now control the mapping between filename extensions and source
6133 languages by using the `set extension-language' command. For instance,
6134 you can ask GDB to treat .c files as C++ by saying
6135 set extension-language .c c++
6136 The command `info extensions' lists all of the recognized extensions
6137 and their associated languages.
6139 * Setting processor type for PowerPC and RS/6000
6141 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6142 you can use the `set processor' command to specify what variant of the
6143 PowerPC family you are debugging. The command
6147 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6148 following PowerPC and RS6000 variants:
6150 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6151 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6153 403GC IBM PowerPC 403GC
6154 505 Motorola PowerPC 505
6155 860 Motorola PowerPC 860 or 850
6156 601 Motorola PowerPC 601
6157 602 Motorola PowerPC 602
6158 603 Motorola/IBM PowerPC 603 or 603e
6159 604 Motorola PowerPC 604 or 604e
6160 750 Motorola/IBM PowerPC 750 or 750
6162 At the moment, this command just tells GDB what to name the
6163 special-purpose processor registers. Since almost all the affected
6164 registers are inaccessible to user-level programs, this command is
6165 only useful for remote debugging in its present form.
6169 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6170 more extensive support for HP-UX. Added features include shared
6171 library support, kernel threads and hardware watchpoints for 11.00,
6172 support for HP's ANSI C and C++ compilers, and a compatibility mode
6173 for xdb and dbx commands.
6177 HP's donation includes the new concept of catchpoints, which is a
6178 generalization of the old catch command. On HP-UX, it is now possible
6179 to catch exec, fork, and vfork, as well as library loading.
6181 This means that the existing catch command has changed; its first
6182 argument now specifies the type of catch to be set up. See the
6183 output of "help catch" for a list of catchpoint types.
6185 * Debugging across forks
6187 On HP-UX, you can choose which process to debug when a fork() happens
6192 HP has donated a curses-based terminal user interface (TUI). To get
6193 it, build with --enable-tui. Although this can be enabled for any
6194 configuration, at present it only works for native HP debugging.
6196 * GDB remote protocol additions
6198 A new protocol packet 'X' that writes binary data is now available.
6199 Default behavior is to try 'X', then drop back to 'M' if the stub
6200 fails to respond. The settable variable `remotebinarydownload'
6201 allows explicit control over the use of 'X'.
6203 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6204 full 64-bit address. The command
6206 set remoteaddresssize 32
6208 can be used to revert to the old behaviour. For existing remote stubs
6209 the change should not be noticed, as the additional address information
6212 In order to assist in debugging stubs, you may use the maintenance
6213 command `packet' to send any text string to the stub. For instance,
6215 maint packet heythere
6217 sends the packet "$heythere#<checksum>". Note that it is very easy to
6218 disrupt a debugging session by sending the wrong packet at the wrong
6221 The compare-sections command allows you to compare section data on the
6222 target to what is in the executable file without uploading or
6223 downloading, by comparing CRC checksums.
6225 * Tracing can collect general expressions
6227 You may now collect general expressions at tracepoints. This requires
6228 further additions to the target-side stub; see tracepoint.c and
6229 doc/agentexpr.texi for further details.
6231 * mask-address variable for Mips
6233 For Mips targets, you may control the zeroing of the upper 32 bits of
6234 a 64-bit address by entering `set mask-address on'. This is mainly
6235 of interest to users of embedded R4xxx and R5xxx processors.
6237 * Higher serial baud rates
6239 GDB's serial code now allows you to specify baud rates 57600, 115200,
6240 230400, and 460800 baud. (Note that your host system may not be able
6241 to achieve all of these rates.)
6245 The i960 configuration now includes an initial implementation of a
6246 builtin simulator, contributed by Jim Wilson.
6249 *** Changes in GDB-4.17:
6251 * New native configurations
6253 Alpha GNU/Linux alpha*-*-linux*
6254 Unixware 2.x i[3456]86-unixware2*
6255 Irix 6.x mips*-sgi-irix6*
6256 PowerPC GNU/Linux powerpc-*-linux*
6257 PowerPC Solaris powerpcle-*-solaris*
6258 Sparc GNU/Linux sparc-*-linux*
6259 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6263 Argonaut Risc Chip (ARC) arc-*-*
6264 Hitachi H8/300S h8300*-*-*
6265 Matsushita MN10200 w/simulator mn10200-*-*
6266 Matsushita MN10300 w/simulator mn10300-*-*
6267 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6268 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6269 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6270 Mitsubishi D10V w/simulator d10v-*-*
6271 Mitsubishi M32R/D w/simulator m32r-*-elf*
6272 Tsqware Sparclet sparclet-*-*
6273 NEC V850 w/simulator v850-*-*
6275 * New debugging protocols
6277 ARM with RDI protocol arm*-*-*
6278 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6279 DDB and LSI variants of PMON protocol mips*-*-*
6280 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6281 PowerPC with SDS protocol powerpc{,le}-*-eabi
6282 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6286 All configurations can now understand and use the DWARF 2 debugging
6287 format. The choice is automatic, if the symbol file contains DWARF 2
6292 GDB now includes basic Java language support. This support is
6293 only useful with Java compilers that produce native machine code.
6295 * solib-absolute-prefix and solib-search-path
6297 For SunOS and SVR4 shared libraries, you may now set the prefix for
6298 loading absolute shared library symbol files, and the search path for
6299 locating non-absolute shared library symbol files.
6301 * Live range splitting
6303 GDB can now effectively debug code for which GCC has performed live
6304 range splitting as part of its optimization. See gdb/doc/LRS for
6305 more details on the expected format of the stabs information.
6309 GDB's support for the GNU Hurd, including thread debugging, has been
6310 updated to work with current versions of the Hurd.
6314 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6315 instruction set. ARM GDB automatically detects when Thumb
6316 instructions are in use, and adjusts disassembly and backtracing
6321 GDB's MIPS target configurations now handle the MIP16 16-bit
6326 GDB now includes support for overlays; if an executable has been
6327 linked such that multiple sections are based at the same address, GDB
6328 will decide which section to use for symbolic info. You can choose to
6329 control the decision manually, using overlay commands, or implement
6330 additional target-side support and use "overlay load-target" to bring
6331 in the overlay mapping. Do "help overlay" for more detail.
6335 The command "info symbol <address>" displays information about
6336 the symbol at the specified address.
6340 The standard remote protocol now includes an extension that allows
6341 asynchronous collection and display of trace data. This requires
6342 extensive support in the target-side debugging stub. Tracing mode
6343 includes a new interaction mode in GDB and new commands: see the
6344 file tracepoint.c for more details.
6348 Configurations for embedded MIPS now include a simulator contributed
6349 by Cygnus Solutions. The simulator supports the instruction sets
6350 of most MIPS variants.
6354 Sparc configurations may now include the ERC32 simulator contributed
6355 by the European Space Agency. The simulator is not built into
6356 Sparc targets by default; configure with --enable-sim to include it.
6360 For target configurations that may include multiple variants of a
6361 basic architecture (such as MIPS and SH), you may now set the
6362 architecture explicitly. "set arch" sets, "info arch" lists
6363 the possible architectures.
6365 *** Changes in GDB-4.16:
6367 * New native configurations
6369 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6370 M68K NetBSD m68k-*-netbsd*
6371 PowerPC AIX 4.x powerpc-*-aix*
6372 PowerPC MacOS powerpc-*-macos*
6373 PowerPC Windows NT powerpcle-*-cygwin32
6374 RS/6000 AIX 4.x rs6000-*-aix4*
6378 ARM with RDP protocol arm-*-*
6379 I960 with MON960 i960-*-coff
6380 MIPS VxWorks mips*-*-vxworks*
6381 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6382 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6384 Matra Sparclet sparclet-*-*
6388 The powerpc-eabi configuration now includes the PSIM simulator,
6389 contributed by Andrew Cagney, with assistance from Mike Meissner.
6390 PSIM is a very elaborate model of the PowerPC, including not only
6391 basic instruction set execution, but also details of execution unit
6392 performance and I/O hardware. See sim/ppc/README for more details.
6396 GDB now works with Solaris 2.5.
6398 * Windows 95/NT native
6400 GDB will now work as a native debugger on Windows 95 and Windows NT.
6401 To build it from source, you must use the "gnu-win32" environment,
6402 which uses a DLL to emulate enough of Unix to run the GNU tools.
6403 Further information, binaries, and sources are available at
6404 ftp.cygnus.com, under pub/gnu-win32.
6406 * dont-repeat command
6408 If a user-defined command includes the command `dont-repeat', then the
6409 command will not be repeated if the user just types return. This is
6410 useful if the command is time-consuming to run, so that accidental
6411 extra keystrokes don't run the same command many times.
6413 * Send break instead of ^C
6415 The standard remote protocol now includes an option to send a break
6416 rather than a ^C to the target in order to interrupt it. By default,
6417 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6419 * Remote protocol timeout
6421 The standard remote protocol includes a new variable `remotetimeout'
6422 that allows you to set the number of seconds before GDB gives up trying
6423 to read from the target. The default value is 2.
6425 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6427 By default GDB will automatically keep track of objects as they are
6428 loaded and unloaded by the dynamic linker. By using the command `set
6429 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6430 when shared library events occur, thus allowing you to set breakpoints
6431 in shared libraries which are explicitly loaded by the inferior.
6433 Note this feature does not work on hpux8. On hpux9 you must link
6434 /usr/lib/end.o into your program. This feature should work
6435 automatically on hpux10.
6437 * Irix 5.x hardware watchpoint support
6439 Irix 5 configurations now support the use of hardware watchpoints.
6441 * Mips protocol "SYN garbage limit"
6443 When debugging a Mips target using the `target mips' protocol, you
6444 may set the number of characters that GDB will ignore by setting
6445 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6446 every character. The default value is 1050.
6448 * Recording and replaying remote debug sessions
6450 If you set `remotelogfile' to the name of a file, gdb will write to it
6451 a recording of a remote debug session. This recording may then be
6452 replayed back to gdb using "gdbreplay". See gdbserver/README for
6453 details. This is useful when you have a problem with GDB while doing
6454 remote debugging; you can make a recording of the session and send it
6455 to someone else, who can then recreate the problem.
6457 * Speedups for remote debugging
6459 GDB includes speedups for downloading and stepping MIPS systems using
6460 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6461 and more efficient S-record downloading.
6463 * Memory use reductions and statistics collection
6465 GDB now uses less memory and reports statistics about memory usage.
6466 Try the `maint print statistics' command, for example.
6468 *** Changes in GDB-4.15:
6470 * Psymtabs for XCOFF
6472 The symbol reader for AIX GDB now uses partial symbol tables. This
6473 can greatly improve startup time, especially for large executables.
6475 * Remote targets use caching
6477 Remote targets now use a data cache to speed up communication with the
6478 remote side. The data cache could lead to incorrect results because
6479 it doesn't know about volatile variables, thus making it impossible to
6480 debug targets which use memory mapped I/O devices. `set remotecache
6481 off' turns the the data cache off.
6483 * Remote targets may have threads
6485 The standard remote protocol now includes support for multiple threads
6486 in the target system, using new protocol commands 'H' and 'T'. See
6487 gdb/remote.c for details.
6491 If GDB is configured with `--enable-netrom', then it will include
6492 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6493 acts as though it is a bank of ROM on the target board, but you can
6494 write into it over the network. GDB's support consists only of
6495 support for fast loading into the emulated ROM; to debug, you must use
6496 another protocol, such as standard remote protocol. The usual
6497 sequence is something like
6499 target nrom <netrom-hostname>
6501 target remote <netrom-hostname>:1235
6505 GDB now includes support for the Apple Macintosh, as a host only. It
6506 may be run as either an MPW tool or as a standalone application, and
6507 it can debug through the serial port. All the usual GDB commands are
6508 available, but to the target command, you must supply "serial" as the
6509 device type instead of "/dev/ttyXX". See mpw-README in the main
6510 directory for more information on how to build. The MPW configuration
6511 scripts */mpw-config.in support only a few targets, and only the
6512 mips-idt-ecoff target has been tested.
6516 GDB configuration now uses autoconf. This is not user-visible,
6517 but does simplify configuration and building.
6521 GDB now supports hpux10.
6523 *** Changes in GDB-4.14:
6525 * New native configurations
6527 x86 FreeBSD i[345]86-*-freebsd
6528 x86 NetBSD i[345]86-*-netbsd
6529 NS32k NetBSD ns32k-*-netbsd
6530 Sparc NetBSD sparc-*-netbsd
6534 A29K VxWorks a29k-*-vxworks
6535 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6536 CPU32 EST-300 emulator m68*-*-est*
6537 PowerPC ELF powerpc-*-elf
6540 * Alpha OSF/1 support for procfs
6542 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6543 possible to attach to running processes. As the mounting of the /proc
6544 filesystem is optional on the Alpha, GDB automatically determines
6545 the availability of /proc during startup. This can lead to problems
6546 if /proc is unmounted after GDB has been started.
6548 * Arguments to user-defined commands
6550 User commands may accept up to 10 arguments separated by whitespace.
6551 Arguments are accessed within the user command via $arg0..$arg9. A
6554 print $arg0 + $arg1 + $arg2
6556 To execute the command use:
6559 Defines the command "adder" which prints the sum of its three arguments.
6560 Note the arguments are text substitutions, so they may reference variables,
6561 use complex expressions, or even perform inferior function calls.
6563 * New `if' and `while' commands
6565 This makes it possible to write more sophisticated user-defined
6566 commands. Both commands take a single argument, which is the
6567 expression to evaluate, and must be followed by the commands to
6568 execute, one per line, if the expression is nonzero, the list being
6569 terminated by the word `end'. The `if' command list may include an
6570 `else' word, which causes the following commands to be executed only
6571 if the expression is zero.
6573 * Fortran source language mode
6575 GDB now includes partial support for Fortran 77. It will recognize
6576 Fortran programs and can evaluate a subset of Fortran expressions, but
6577 variables and functions may not be handled correctly. GDB will work
6578 with G77, but does not yet know much about symbols emitted by other
6581 * Better HPUX support
6583 Most debugging facilities now work on dynamic executables for HPPAs
6584 running hpux9 or later. You can attach to running dynamically linked
6585 processes, but by default the dynamic libraries will be read-only, so
6586 for instance you won't be able to put breakpoints in them. To change
6587 that behavior do the following before running the program:
6593 This will cause the libraries to be mapped private and read-write.
6594 To revert to the normal behavior, do this:
6600 You cannot set breakpoints or examine data in the library until after
6601 the library is loaded if the function/data symbols do not have
6604 GDB can now also read debug symbols produced by the HP C compiler on
6605 HPPAs (sorry, no C++, Fortran or 68k support).
6607 * Target byte order now dynamically selectable
6609 You can choose which byte order to use with a target system, via the
6610 commands "set endian big" and "set endian little", and you can see the
6611 current setting by using "show endian". You can also give the command
6612 "set endian auto", in which case GDB will use the byte order
6613 associated with the executable. Currently, only embedded MIPS
6614 configurations support dynamic selection of target byte order.
6616 * New DOS host serial code
6618 This version uses DPMI interrupts to handle buffered I/O, so you
6619 no longer need to run asynctsr when debugging boards connected to
6622 *** Changes in GDB-4.13:
6624 * New "complete" command
6626 This lists all the possible completions for the rest of the line, if it
6627 were to be given as a command itself. This is intended for use by emacs.
6629 * Trailing space optional in prompt
6631 "set prompt" no longer adds a space for you after the prompt you set. This
6632 allows you to set a prompt which ends in a space or one that does not.
6634 * Breakpoint hit counts
6636 "info break" now displays a count of the number of times the breakpoint
6637 has been hit. This is especially useful in conjunction with "ignore"; you
6638 can ignore a large number of breakpoint hits, look at the breakpoint info
6639 to see how many times the breakpoint was hit, then run again, ignoring one
6640 less than that number, and this will get you quickly to the last hit of
6643 * Ability to stop printing at NULL character
6645 "set print null-stop" will cause GDB to stop printing the characters of
6646 an array when the first NULL is encountered. This is useful when large
6647 arrays actually contain only short strings.
6649 * Shared library breakpoints
6651 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6652 breakpoints in shared libraries before the executable is run.
6654 * Hardware watchpoints
6656 There is a new hardware breakpoint for the watch command for sparclite
6657 targets. See gdb/sparclite/hw_breakpoint.note.
6659 Hardware watchpoints are also now supported under GNU/Linux.
6663 Annotations have been added. These are for use with graphical interfaces,
6664 and are still experimental. Currently only gdba.el uses these.
6666 * Improved Irix 5 support
6668 GDB now works properly with Irix 5.2.
6670 * Improved HPPA support
6672 GDB now works properly with the latest GCC and GAS.
6674 * New native configurations
6676 Sequent PTX4 i[34]86-sequent-ptx4
6677 HPPA running OSF/1 hppa*-*-osf*
6678 Atari TT running SVR4 m68*-*-sysv4*
6679 RS/6000 LynxOS rs6000-*-lynxos*
6683 OS/9000 i[34]86-*-os9k
6684 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6687 * Hitachi SH7000 and E7000-PC ICE support
6689 There is now support for communicating with the Hitachi E7000-PC ICE.
6690 This is available automatically when GDB is configured for the SH.
6694 As usual, a variety of small fixes and improvements, both generic
6695 and configuration-specific. See the ChangeLog for more detail.
6697 *** Changes in GDB-4.12:
6699 * Irix 5 is now supported
6703 GDB-4.12 on the HPPA has a number of changes which make it unable
6704 to debug the output from the currently released versions of GCC and
6705 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6706 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6707 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6710 *** Changes in GDB-4.11:
6712 * User visible changes:
6716 The "set remotedebug" option is now consistent between the mips remote
6717 target, remote targets using the gdb-specific protocol, UDI (AMD's
6718 debug protocol for the 29k) and the 88k bug monitor. It is now an
6719 integer specifying a debug level (normally 0 or 1, but 2 means more
6720 debugging info for the mips target).
6722 * DEC Alpha native support
6724 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6725 debug info, but GDB works fairly well with the DEC compiler and should
6726 work with a future GCC release. See the README file for a few
6727 Alpha-specific notes.
6729 * Preliminary thread implementation
6731 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6733 * LynxOS native and target support for 386
6735 This release has been hosted on LynxOS 2.2, and also can be configured
6736 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6739 * Improvements in C++ mangling/demangling.
6741 This release has much better g++ debugging, specifically in name
6742 mangling/demangling, virtual function calls, print virtual table,
6743 call methods, ...etc.
6745 *** Changes in GDB-4.10:
6747 * User visible changes:
6749 Remote debugging using the GDB-specific (`target remote') protocol now
6750 supports the `load' command. This is only useful if you have some
6751 other way of getting the stub to the target system, and you can put it
6752 somewhere in memory where it won't get clobbered by the download.
6754 Filename completion now works.
6756 When run under emacs mode, the "info line" command now causes the
6757 arrow to point to the line specified. Also, "info line" prints
6758 addresses in symbolic form (as well as hex).
6760 All vxworks based targets now support a user settable option, called
6761 vxworks-timeout. This option represents the number of seconds gdb
6762 should wait for responses to rpc's. You might want to use this if
6763 your vxworks target is, perhaps, a slow software simulator or happens
6764 to be on the far side of a thin network line.
6768 This release contains support for using a DEC alpha as a GDB host for
6769 cross debugging. Native alpha debugging is not supported yet.
6772 *** Changes in GDB-4.9:
6776 This is the first GDB release which is accompanied by a matching testsuite.
6777 The testsuite requires installation of dejagnu, which should be available
6778 via ftp from most sites that carry GNU software.
6782 'Cfront' style demangling has had its name changed to 'ARM' style, to
6783 emphasize that it was written from the specifications in the C++ Annotated
6784 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6785 disclaimers, it still generated too much confusion with users attempting to
6786 use gdb with AT&T cfront.
6790 GDB now uses a standard remote interface to a simulator library.
6791 So far, the library contains simulators for the Zilog Z8001/2, the
6792 Hitachi H8/300, H8/500 and Super-H.
6794 * New targets supported
6796 H8/300 simulator h8300-hitachi-hms or h8300hms
6797 H8/500 simulator h8500-hitachi-hms or h8500hms
6798 SH simulator sh-hitachi-hms or sh
6799 Z8000 simulator z8k-zilog-none or z8ksim
6800 IDT MIPS board over serial line mips-idt-ecoff
6802 Cross-debugging to GO32 targets is supported. It requires a custom
6803 version of the i386-stub.c module which is integrated with the
6804 GO32 memory extender.
6806 * New remote protocols
6808 MIPS remote debugging protocol.
6810 * New source languages supported
6812 This version includes preliminary support for Chill, a Pascal like language
6813 used by telecommunications companies. Chill support is also being integrated
6814 into the GNU compiler, but we don't know when it will be publically available.
6817 *** Changes in GDB-4.8:
6819 * HP Precision Architecture supported
6821 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6822 version of this support was available as a set of patches from the
6823 University of Utah. GDB does not support debugging of programs
6824 compiled with the HP compiler, because HP will not document their file
6825 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6826 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6828 Many problems in the preliminary version have been fixed.
6830 * Faster and better demangling
6832 We have improved template demangling and fixed numerous bugs in the GNU style
6833 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6834 character types (wchar_t) are now supported. Demangling of each symbol is now
6835 only done once, and is cached when the symbol table for a file is read in.
6836 This results in a small increase in memory usage for C programs, a moderate
6837 increase in memory usage for C++ programs, and a fantastic speedup in
6840 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6841 from the specifications in the Annotated Reference Manual, which AT&T's
6842 compiler does not actually implement.
6844 * G++ multiple inheritance compiler problem
6846 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6847 inheritance lattices was reworked to properly discover ambiguities. We
6848 recently found an example which causes this new algorithm to fail in a
6849 very subtle way, producing bad debug information for those classes.
6850 The file 'gcc.patch' (in this directory) can be applied to gcc to
6851 circumvent the problem. A future GCC release will contain a complete
6854 The previous G++ debug info problem (mentioned below for the gdb-4.7
6855 release) is fixed in gcc version 2.3.2.
6857 * Improved configure script
6859 The `configure' script will now attempt to guess your system type if
6860 you don't supply a host system type. The old scheme of supplying a
6861 host system triplet is preferable over using this. All the magic is
6862 done in the new `config.guess' script. Examine it for details.
6864 We have also brought our configure script much more in line with the FSF's
6865 version. It now supports the --with-xxx options. In particular,
6866 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6867 The resulting GDB will not be able to read arbitrary object file formats --
6868 only the format ``expected'' to be used on the configured target system.
6869 We hope to make this the default in a future release.
6871 * Documentation improvements
6873 There's new internal documentation on how to modify GDB, and how to
6874 produce clean changes to the code. We implore people to read it
6875 before submitting changes.
6877 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6878 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6879 `info' files are also provided. To build `info' files from scratch,
6880 you will need the latest `makeinfo' release, which will be available in
6881 a future texinfo-X.Y release.
6883 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6884 We're not sure exactly which versions have this problem, but it has
6885 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6886 or better. If that isn't possible, there is a patch in
6887 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6888 around this problem.
6892 GDB now supports array constants that can be used in expressions typed in by
6893 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6894 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6897 The new directory `gdb/sparclite' contains a program that demonstrates
6898 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6900 * New native hosts supported
6902 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6903 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6905 * New targets supported
6907 AMD 29k family via UDI a29k-amd-udi or udi29k
6909 * New file formats supported
6911 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6912 HPUX core files, and SCO 3.2v2 core files.
6916 Attaching to processes now works again; thanks for the many bug reports.
6918 We have also stomped on a bunch of core dumps caused by
6919 printf_filtered("%s") problems.
6921 We eliminated a copyright problem on the rpc and ptrace header files
6922 for VxWorks, which was discovered at the last minute during the 4.7
6923 release. You should now be able to build a VxWorks GDB.
6925 You can now interrupt gdb while an attached process is running. This
6926 will cause the attached process to stop, and give control back to GDB.
6928 We fixed problems caused by using too many file descriptors
6929 for reading symbols from object files and libraries. This was
6930 especially a problem for programs that used many (~100) shared
6933 The `step' command now only enters a subroutine if there is line number
6934 information for the subroutine. Otherwise it acts like the `next'
6935 command. Previously, `step' would enter subroutines if there was
6936 any debugging information about the routine. This avoids problems
6937 when using `cc -g1' on MIPS machines.
6939 * Internal improvements
6941 GDB's internal interfaces have been improved to make it easier to support
6942 debugging of multiple languages in the future.
6944 GDB now uses a common structure for symbol information internally.
6945 Minimal symbols (derived from linkage symbols in object files), partial
6946 symbols (from a quick scan of debug information), and full symbols
6947 contain a common subset of information, making it easier to write
6948 shared code that handles any of them.
6950 * New command line options
6952 We now accept --silent as an alias for --quiet.
6956 The memory-mapped-malloc library is now licensed under the GNU Library
6957 General Public License.
6959 *** Changes in GDB-4.7:
6961 * Host/native/target split
6963 GDB has had some major internal surgery to untangle the support for
6964 hosts and remote targets. Now, when you configure GDB for a remote
6965 target, it will no longer load in all of the support for debugging
6966 local programs on the host. When fully completed and tested, this will
6967 ensure that arbitrary host/target combinations are possible.
6969 The primary conceptual shift is to separate the non-portable code in
6970 GDB into three categories. Host specific code is required any time GDB
6971 is compiled on that host, regardless of the target. Target specific
6972 code relates to the peculiarities of the target, but can be compiled on
6973 any host. Native specific code is everything else: it can only be
6974 built when the host and target are the same system. Child process
6975 handling and core file support are two common `native' examples.
6977 GDB's use of /proc for controlling Unix child processes is now cleaner.
6978 It has been split out into a single module under the `target_ops' vector,
6979 plus two native-dependent functions for each system that uses /proc.
6981 * New hosts supported
6983 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6984 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6985 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6987 * New targets supported
6989 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6990 68030 and CPU32 m68030-*-*, m68332-*-*
6992 * New native hosts supported
6994 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6995 (386bsd is not well tested yet)
6996 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6998 * New file formats supported
7000 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7001 supports reading of `a.out.adobe' object files, which are an a.out
7002 format extended with minimal information about multiple sections.
7006 `show copying' is the same as the old `info copying'.
7007 `show warranty' is the same as `info warrantee'.
7008 These were renamed for consistency. The old commands continue to work.
7010 `info handle' is a new alias for `info signals'.
7012 You can now define pre-command hooks, which attach arbitrary command
7013 scripts to any command. The commands in the hook will be executed
7014 prior to the user's command. You can also create a hook which will be
7015 executed whenever the program stops. See gdb.texinfo.
7019 We now deal with Cfront style name mangling, and can even extract type
7020 info from mangled symbols. GDB can automatically figure out which
7021 symbol mangling style your C++ compiler uses.
7023 Calling of methods and virtual functions has been improved as well.
7027 The crash that occured when debugging Sun Ansi-C compiled binaries is
7028 fixed. This was due to mishandling of the extra N_SO stabs output
7031 We also finally got Ultrix 4.2 running in house, and fixed core file
7032 support, with help from a dozen people on the net.
7034 John M. Farrell discovered that the reason that single-stepping was so
7035 slow on all of the Mips based platforms (primarily SGI and DEC) was
7036 that we were trying to demangle and lookup a symbol used for internal
7037 purposes on every instruction that was being stepped through. Changing
7038 the name of that symbol so that it couldn't be mistaken for a C++
7039 mangled symbol sped things up a great deal.
7041 Rich Pixley sped up symbol lookups in general by getting much smarter
7042 about when C++ symbol mangling is necessary. This should make symbol
7043 completion (TAB on the command line) much faster. It's not as fast as
7044 we'd like, but it's significantly faster than gdb-4.6.
7048 A new user controllable variable 'call_scratch_address' can
7049 specify the location of a scratch area to be used when GDB
7050 calls a function in the target. This is necessary because the
7051 usual method of putting the scratch area on the stack does not work
7052 in systems that have separate instruction and data spaces.
7054 We integrated changes to support the 29k UDI (Universal Debugger
7055 Interface), but discovered at the last minute that we didn't have all
7056 of the appropriate copyright paperwork. We are working with AMD to
7057 resolve this, and hope to have it available soon.
7061 We have sped up the remote serial line protocol, especially for targets
7062 with lots of registers. It now supports a new `expedited status' ('T')
7063 message which can be used in place of the existing 'S' status message.
7064 This allows the remote stub to send only the registers that GDB
7065 needs to make a quick decision about single-stepping or conditional
7066 breakpoints, eliminating the need to fetch the entire register set for
7067 each instruction being stepped through.
7069 The GDB remote serial protocol now implements a write-through cache for
7070 registers, only re-reading the registers if the target has run.
7072 There is also a new remote serial stub for SPARC processors. You can
7073 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7074 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7075 processor with a serial port.
7079 Configure.in files have become much easier to read and modify. A new
7080 `table driven' format makes it more obvious what configurations are
7081 supported, and what files each one uses.
7085 There is a new opcodes library which will eventually contain all of the
7086 disassembly routines and opcode tables. At present, it only contains
7087 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7088 disassembler (binutils/objdump) to share these routines.
7090 The libiberty library is now copylefted under the GNU Library General
7091 Public License. This allows more liberal use, and was done so libg++
7092 can use it. This makes no difference to GDB, since the Library License
7093 grants all the rights from the General Public License.
7097 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7098 reference to the stabs symbol info used by the debugger. It is (as far
7099 as we know) the only published document on this fascinating topic. We
7100 encourage you to read it, compare it to the stabs information on your
7101 system, and send improvements on the document in general (to
7102 bug-gdb@prep.ai.mit.edu).
7104 And, of course, many bugs have been fixed.
7107 *** Changes in GDB-4.6:
7109 * Better support for C++ function names
7111 GDB now accepts as input the "demangled form" of C++ overloaded function
7112 names and member function names, and can do command completion on such names
7113 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7114 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7115 Make use of command completion, it is your friend.
7117 GDB also now accepts a variety of C++ mangled symbol formats. They are
7118 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7119 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7120 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7121 for the list of formats.
7123 * G++ symbol mangling problem
7125 Recent versions of gcc have a bug in how they emit debugging information for
7126 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7127 directory) can be applied to gcc to fix the problem. Alternatively, if you
7128 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7129 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7130 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7133 * New 'maintenance' command
7135 All of the commands related to hacking GDB internals have been moved out of
7136 the main command set, and now live behind the 'maintenance' command. This
7137 can also be abbreviated as 'mt'. The following changes were made:
7139 dump-me -> maintenance dump-me
7140 info all-breakpoints -> maintenance info breakpoints
7141 printmsyms -> maintenance print msyms
7142 printobjfiles -> maintenance print objfiles
7143 printpsyms -> maintenance print psymbols
7144 printsyms -> maintenance print symbols
7146 The following commands are new:
7148 maintenance demangle Call internal GDB demangler routine to
7149 demangle a C++ link name and prints the result.
7150 maintenance print type Print a type chain for a given symbol
7152 * Change to .gdbinit file processing
7154 We now read the $HOME/.gdbinit file before processing the argv arguments
7155 (e.g. reading symbol files or core files). This allows global parameters to
7156 be set, which will apply during the symbol reading. The ./.gdbinit is still
7157 read after argv processing.
7159 * New hosts supported
7161 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7163 GNU/Linux support i386-unknown-linux or linux
7165 We are also including code to support the HP/PA running BSD and HPUX. This
7166 is almost guaranteed not to work, as we didn't have time to test or build it
7167 for this release. We are including it so that the more adventurous (or
7168 masochistic) of you can play with it. We also had major problems with the
7169 fact that the compiler that we got from HP doesn't support the -g option.
7172 * New targets supported
7174 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7176 * More smarts about finding #include files
7178 GDB now remembers the compilation directory for all include files, and for
7179 all files from which C is generated (like yacc and lex sources). This
7180 greatly improves GDB's ability to find yacc/lex sources, and include files,
7181 especially if you are debugging your program from a directory different from
7182 the one that contains your sources.
7184 We also fixed a bug which caused difficulty with listing and setting
7185 breakpoints in include files which contain C code. (In the past, you had to
7186 try twice in order to list an include file that you hadn't looked at before.)
7188 * Interesting infernals change
7190 GDB now deals with arbitrary numbers of sections, where the symbols for each
7191 section must be relocated relative to that section's landing place in the
7192 target's address space. This work was needed to support ELF with embedded
7193 stabs used by Solaris-2.0.
7195 * Bug fixes (of course!)
7197 There have been loads of fixes for the following things:
7198 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7199 i960, stabs, DOS(GO32), procfs, etc...
7201 See the ChangeLog for details.
7203 *** Changes in GDB-4.5:
7205 * New machines supported (host and target)
7207 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7209 SGI Irix-4.x mips-sgi-irix4 or iris4
7211 * New malloc package
7213 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7214 Mmalloc is capable of handling mutiple heaps of memory. It is also
7215 capable of saving a heap to a file, and then mapping it back in later.
7216 This can be used to greatly speedup the startup of GDB by using a
7217 pre-parsed symbol table which lives in a mmalloc managed heap. For
7218 more details, please read mmalloc/mmalloc.texi.
7222 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7223 'help info proc' for details.
7225 * MIPS ecoff symbol table format
7227 The code that reads MIPS symbol table format is now supported on all hosts.
7228 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7231 * File name changes for MS-DOS
7233 Many files in the config directories have been renamed to make it easier to
7234 support GDB on MS-DOSe systems (which have very restrictive file name
7235 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7236 environment) is close to working but has some remaining problems. Note
7237 that debugging of DOS programs is not supported, due to limitations
7238 in the ``operating system'', but it can be used to host cross-debugging.
7240 * Cross byte order fixes
7242 Many fixes have been made to support cross debugging of Sparc and MIPS
7243 targets from hosts whose byte order differs.
7245 * New -mapped and -readnow options
7247 If memory-mapped files are available on your system through the 'mmap'
7248 system call, you can use the -mapped option on the `file' or
7249 `symbol-file' commands to cause GDB to write the symbols from your
7250 program into a reusable file. If the program you are debugging is
7251 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7252 Future GDB debugging sessions will notice the presence of this file,
7253 and will quickly map in symbol information from it, rather than reading
7254 the symbol table from the executable program. Using the '-mapped'
7255 option in a GDB `file' or `symbol-file' command has the same effect as
7256 starting GDB with the '-mapped' command-line option.
7258 You can cause GDB to read the entire symbol table immediately by using
7259 the '-readnow' option with any of the commands that load symbol table
7260 information (or on the GDB command line). This makes the command
7261 slower, but makes future operations faster.
7263 The -mapped and -readnow options are typically combined in order to
7264 build a `fred.syms' file that contains complete symbol information.
7265 A simple GDB invocation to do nothing but build a `.syms' file for future
7268 gdb -batch -nx -mapped -readnow programname
7270 The `.syms' file is specific to the host machine on which GDB is run.
7271 It holds an exact image of GDB's internal symbol table. It cannot be
7272 shared across multiple host platforms.
7274 * longjmp() handling
7276 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7277 siglongjmp() without losing control. This feature has not yet been ported to
7278 all systems. It currently works on many 386 platforms, all MIPS-based
7279 platforms (SGI, DECstation, etc), and Sun3/4.
7283 Preliminary work has been put in to support the new Solaris OS from Sun. At
7284 this time, it can control and debug processes, but it is not capable of
7289 As always, many many bug fixes. The major areas were with g++, and mipsread.
7290 People using the MIPS-based platforms should experience fewer mysterious
7291 crashes and trashed symbol tables.
7293 *** Changes in GDB-4.4:
7295 * New machines supported (host and target)
7297 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7299 BSD Reno on Vax vax-dec-bsd
7300 Ultrix on Vax vax-dec-ultrix
7302 * New machines supported (target)
7304 AMD 29000 embedded, using EBMON a29k-none-none
7308 GDB continues to improve its handling of C++. `References' work better.
7309 The demangler has also been improved, and now deals with symbols mangled as
7310 per the Annotated C++ Reference Guide.
7312 GDB also now handles `stabs' symbol information embedded in MIPS
7313 `ecoff' symbol tables. Since the ecoff format was not easily
7314 extensible to handle new languages such as C++, this appeared to be a
7315 good way to put C++ debugging info into MIPS binaries. This option
7316 will be supported in the GNU C compiler, version 2, when it is
7319 * New features for SVR4
7321 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7322 shared libraries. Debugging dynamically linked programs should present
7323 only minor differences from debugging statically linked programs.
7325 The `info proc' command will print out information about any process
7326 on an SVR4 system (including the one you are debugging). At the moment,
7327 it prints the address mappings of the process.
7329 If you bring up GDB on another SVR4 system, please send mail to
7330 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7332 * Better dynamic linking support in SunOS
7334 Reading symbols from shared libraries which contain debugging symbols
7335 now works properly. However, there remain issues such as automatic
7336 skipping of `transfer vector' code during function calls, which
7337 make it harder to debug code in a shared library, than to debug the
7338 same code linked statically.
7342 GDB is now using the latest `getopt' routines from the FSF. This
7343 version accepts the -- prefix for options with long names. GDB will
7344 continue to accept the old forms (-option and +option) as well.
7345 Various single letter abbreviations for options have been explicity
7346 added to the option table so that they won't get overshadowed in the
7347 future by other options that begin with the same letter.
7351 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7352 Many assorted bugs have been handled. Many more remain to be handled.
7353 See the various ChangeLog files (primarily in gdb and bfd) for details.
7356 *** Changes in GDB-4.3:
7358 * New machines supported (host and target)
7360 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7361 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7362 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7364 * Almost SCO Unix support
7366 We had hoped to support:
7367 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7368 (except for core file support), but we discovered very late in the release
7369 that it has problems with process groups that render gdb unusable. Sorry
7370 about that. I encourage people to fix it and post the fixes.
7372 * Preliminary ELF and DWARF support
7374 GDB can read ELF object files on System V Release 4, and can handle
7375 debugging records for C, in DWARF format, in ELF files. This support
7376 is preliminary. If you bring up GDB on another SVR4 system, please
7377 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7382 GDB now uses the latest `readline' library. One user-visible change
7383 is that two tabs will list possible command completions, which previously
7384 required typing M-? (meta-question mark, or ESC ?).
7388 The `stepi' bug that many of you noticed has been squashed.
7389 Many bugs in C++ have been handled. Many more remain to be handled.
7390 See the various ChangeLog files (primarily in gdb and bfd) for details.
7392 * State of the MIPS world (in case you wondered):
7394 GDB can understand the symbol tables emitted by the compilers
7395 supplied by most vendors of MIPS-based machines, including DEC. These
7396 symbol tables are in a format that essentially nobody else uses.
7398 Some versions of gcc come with an assembler post-processor called
7399 mips-tfile. This program is required if you want to do source-level
7400 debugging of gcc-compiled programs. I believe FSF does not ship
7401 mips-tfile with gcc version 1, but it will eventually come with gcc
7404 Debugging of g++ output remains a problem. g++ version 1.xx does not
7405 really support it at all. (If you're lucky, you should be able to get
7406 line numbers and stack traces to work, but no parameters or local
7407 variables.) With some work it should be possible to improve the
7410 When gcc version 2 is released, you will have somewhat better luck.
7411 However, even then you will get confusing results for inheritance and
7414 We will eventually provide full debugging of g++ output on
7415 DECstations. This will probably involve some kind of stabs-in-ecoff
7416 encapulation, but the details have not been worked out yet.
7419 *** Changes in GDB-4.2:
7421 * Improved configuration
7423 Only one copy of `configure' exists now, and it is not self-modifying.
7424 Porting BFD is simpler.
7428 The `step' and `next' commands now only stop at the first instruction
7429 of a source line. This prevents the multiple stops that used to occur
7430 in switch statements, for-loops, etc. `Step' continues to stop if a
7431 function that has debugging information is called within the line.
7435 Lots of small bugs fixed. More remain.
7437 * New host supported (not target)
7439 Intel 386 PC clone running Mach i386-none-mach
7442 *** Changes in GDB-4.1:
7444 * Multiple source language support
7446 GDB now has internal scaffolding to handle several source languages.
7447 It determines the type of each source file from its filename extension,
7448 and will switch expression parsing and number formatting to match the
7449 language of the function in the currently selected stack frame.
7450 You can also specifically set the language to be used, with
7451 `set language c' or `set language modula-2'.
7455 GDB now has preliminary support for the GNU Modula-2 compiler,
7456 currently under development at the State University of New York at
7457 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7458 continue through the fall of 1991 and into 1992.
7460 Other Modula-2 compilers are currently not supported, and attempting to
7461 debug programs compiled with them will likely result in an error as the
7462 symbol table is read. Feel free to work on it, though!
7464 There are hooks in GDB for strict type checking and range checking,
7465 in the `Modula-2 philosophy', but they do not currently work.
7469 GDB can now write to executable and core files (e.g. patch
7470 a variable's value). You must turn this switch on, specify
7471 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7472 by assigning a new value to a variable. Modifications take
7475 * Automatic SunOS shared library reading
7477 When you run your program, GDB automatically determines where its
7478 shared libraries (if any) have been loaded, and reads their symbols.
7479 The `share' command is no longer needed. This also works when
7480 examining core files.
7484 You can specify the number of lines that the `list' command shows.
7487 * New machines supported (host and target)
7489 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7490 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7491 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7493 * New hosts supported (not targets)
7495 IBM RT/PC: romp-ibm-aix or rtpc
7497 * New targets supported (not hosts)
7499 AMD 29000 embedded with COFF a29k-none-coff
7500 AMD 29000 embedded with a.out a29k-none-aout
7501 Ultracomputer remote kernel debug a29k-nyu-kern
7503 * New remote interfaces
7509 *** Changes in GDB-4.0:
7513 Wide output is wrapped at good places to make the output more readable.
7515 Gdb now supports cross-debugging from a host machine of one type to a
7516 target machine of another type. Communication with the target system
7517 is over serial lines. The ``target'' command handles connecting to the
7518 remote system; the ``load'' command will download a program into the
7519 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7520 also supports debugging of realtime processes running under VxWorks,
7521 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7522 stub on the target system.
7524 New CPUs supported include the AMD 29000 and Intel 960.
7526 GDB now reads object files and symbol tables via a ``binary file''
7527 library, which allows a single copy of GDB to debug programs of multiple
7528 object file types such as a.out and coff.
7530 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7531 refcard.dvi and refcard.ps are available to format it).
7534 * Control-Variable user interface simplified
7536 All variables that control the operation of the debugger can be set
7537 by the ``set'' command, and displayed by the ``show'' command.
7539 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7540 ``Show prompt'' produces the response:
7541 Gdb's prompt is new-gdb=>.
7543 What follows are the NEW set commands. The command ``help set'' will
7544 print a complete list of old and new set commands. ``help set FOO''
7545 will give a longer description of the variable FOO. ``show'' will show
7546 all of the variable descriptions and their current settings.
7548 confirm on/off: Enables warning questions for operations that are
7549 hard to recover from, e.g. rerunning the program while
7550 it is already running. Default is ON.
7552 editing on/off: Enables EMACS style command line editing
7553 of input. Previous lines can be recalled with
7554 control-P, the current line can be edited with control-B,
7555 you can search for commands with control-R, etc.
7558 history filename NAME: NAME is where the gdb command history
7559 will be stored. The default is .gdb_history,
7560 or the value of the environment variable
7563 history size N: The size, in commands, of the command history. The
7564 default is 256, or the value of the environment variable
7567 history save on/off: If this value is set to ON, the history file will
7568 be saved after exiting gdb. If set to OFF, the
7569 file will not be saved. The default is OFF.
7571 history expansion on/off: If this value is set to ON, then csh-like
7572 history expansion will be performed on
7573 command line input. The default is OFF.
7575 radix N: Sets the default radix for input and output. It can be set
7576 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7577 in the current radix, so "set radix 10" is always a no-op.
7579 height N: This integer value is the number of lines on a page. Default
7580 is 24, the current `stty rows'' setting, or the ``li#''
7581 setting from the termcap entry matching the environment
7584 width N: This integer value is the number of characters on a line.
7585 Default is 80, the current `stty cols'' setting, or the ``co#''
7586 setting from the termcap entry matching the environment
7589 Note: ``set screensize'' is obsolete. Use ``set height'' and
7590 ``set width'' instead.
7592 print address on/off: Print memory addresses in various command displays,
7593 such as stack traces and structure values. Gdb looks
7594 more ``symbolic'' if you turn this off; it looks more
7595 ``machine level'' with it on. Default is ON.
7597 print array on/off: Prettyprint arrays. New convenient format! Default
7600 print demangle on/off: Print C++ symbols in "source" form if on,
7603 print asm-demangle on/off: Same, for assembler level printouts
7606 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7609 * Support for Epoch Environment.
7611 The epoch environment is a version of Emacs v18 with windowing. One
7612 new command, ``inspect'', is identical to ``print'', except that if you
7613 are running in the epoch environment, the value is printed in its own
7617 * Support for Shared Libraries
7619 GDB can now debug programs and core files that use SunOS shared libraries.
7620 Symbols from a shared library cannot be referenced
7621 before the shared library has been linked with the program (this
7622 happens after you type ``run'' and before the function main() is entered).
7623 At any time after this linking (including when examining core files
7624 from dynamically linked programs), gdb reads the symbols from each
7625 shared library when you type the ``sharedlibrary'' command.
7626 It can be abbreviated ``share''.
7628 sharedlibrary REGEXP: Load shared object library symbols for files
7629 matching a unix regular expression. No argument
7630 indicates to load symbols for all shared libraries.
7632 info sharedlibrary: Status of loaded shared libraries.
7637 A watchpoint stops execution of a program whenever the value of an
7638 expression changes. Checking for this slows down execution
7639 tremendously whenever you are in the scope of the expression, but is
7640 quite useful for catching tough ``bit-spreader'' or pointer misuse
7641 problems. Some machines such as the 386 have hardware for doing this
7642 more quickly, and future versions of gdb will use this hardware.
7644 watch EXP: Set a watchpoint (breakpoint) for an expression.
7646 info watchpoints: Information about your watchpoints.
7648 delete N: Deletes watchpoint number N (same as breakpoints).
7649 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7650 enable N: Re-enables watchpoint number N (same as breakpoints).
7653 * C++ multiple inheritance
7655 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7658 * C++ exception handling
7660 Gdb now supports limited C++ exception handling. Besides the existing
7661 ability to breakpoint on an exception handler, gdb can breakpoint on
7662 the raising of an exception (before the stack is peeled back to the
7665 catch FOO: If there is a FOO exception handler in the dynamic scope,
7666 set a breakpoint to catch exceptions which may be raised there.
7667 Multiple exceptions (``catch foo bar baz'') may be caught.
7669 info catch: Lists all exceptions which may be caught in the
7670 current stack frame.
7673 * Minor command changes
7675 The command ``call func (arg, arg, ...)'' now acts like the print
7676 command, except it does not print or save a value if the function's result
7677 is void. This is similar to dbx usage.
7679 The ``up'' and ``down'' commands now always print the frame they end up
7680 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7681 frames without printing.
7683 * New directory command
7685 'dir' now adds directories to the FRONT of the source search path.
7686 The path starts off empty. Source files that contain debug information
7687 about the directory in which they were compiled can be found even
7688 with an empty path; Sun CC and GCC include this information. If GDB can't
7689 find your source file in the current directory, type "dir .".
7691 * Configuring GDB for compilation
7693 For normal use, type ``./configure host''. See README or gdb.texinfo
7696 GDB now handles cross debugging. If you are remotely debugging between
7697 two different machines, type ``./configure host -target=targ''.
7698 Host is the machine where GDB will run; targ is the machine
7699 where the program that you are debugging will run.