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 * GDB now supports Thread Local Storage (TLS) variables on several
15 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
16 architectures require kernel changes. TLS is not yet supported for
17 amd64 and i386 process core dumps.
19 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
20 addresses that required unmasking are shown in the backtrace with the
23 * Two new convenience functions $_cimag and $_creal that extract the
24 imaginary and real parts respectively from complex numbers.
26 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
27 provide the exitcode or exit status of the shell commands launched by
28 GDB commands such as "shell", "pipe" and "make".
30 * The RX port now supports XML target descriptions.
32 * GDB now shows the Ada task names at more places, e.g. in task switching
35 * GDB can now be compiled with Python 3 on Windows.
37 * New convenience variable $_ada_exception holds the address of the
38 Ada exception being thrown. This is set by Ada-related catchpoints.
40 * GDB can now place breakpoints on nested functions and subroutines in
41 Fortran code. The '::' operator can be used between parent and
42 child scopes when placing breakpoints, for example:
44 (gdb) break outer_function::inner_function
46 The 'outer_function::' prefix is only needed if 'inner_function' is
47 not visible in the current scope.
49 * In addition to the system-wide gdbinit file, if configured with
50 --with-system-gdbinit-dir, GDB will now also load files in that directory
51 as system gdbinit files, unless the -nx or -n flag is provided. Files
52 with extensions .gdb, .py and .scm are supported as long as GDB was
53 compiled with support for that language.
57 ** The gdb.Value type has a new method 'format_string' which returns a
58 string representing the value. The formatting is controlled by the
59 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
60 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
61 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
63 ** gdb.Type has a new property 'objfile' which returns the objfile the
66 ** The frame information printed by the python frame filtering code
67 is now consistent with what the 'backtrace' command prints when
68 there are no filters, or when the 'backtrace' '-no-filters' option
71 ** The new function gdb.lookup_static_symbol can be used to look up
72 symbols with static linkage.
74 ** gdb.Objfile has new methods 'lookup_global_symbol' and
75 'lookup_static_symbol' to lookup a symbol from this objfile only.
77 ** gdb.Block now supports the dictionary syntax for accessing symbols in
78 this block (e.g. block['local_variable']).
82 | [COMMAND] | SHELL_COMMAND
83 | -d DELIM COMMAND DELIM SHELL_COMMAND
84 pipe [COMMAND] | SHELL_COMMAND
85 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
86 Executes COMMAND and sends its output to SHELL_COMMAND.
87 With no COMMAND, repeat the last executed command
88 and send its output to SHELL_COMMAND.
90 with SETTING [VALUE] [-- COMMAND]
91 w SETTING [VALUE] [-- COMMAND]
92 Temporarily set SETTING, run COMMAND, and restore SETTING.
93 Usage: with SETTING -- COMMAND
94 With no COMMAND, repeats the last executed command.
95 SETTING is any GDB setting you can change with the "set"
96 subcommands. For example, 'with language c -- print someobj'
97 temporarily switches to the C language in order to print someobj.
98 Settings can be combined: 'w lang c -- w print elements unlimited --
99 usercmd' switches to the C language and runs usercmd with no limit
100 of array elements to print.
102 maint with SETTING [VALUE] [-- COMMAND]
103 Like "with", but works with "maintenance set" settings.
105 set may-call-functions [on|off]
106 show may-call-functions
107 This controls whether GDB will attempt to call functions in
108 the program, such as with expressions in the print command. It
109 defaults to on. Calling functions in the program being debugged
110 can have undesired side effects. It is now possible to forbid
111 such function calls. If function calls are forbidden, GDB will throw
112 an error when a command (such as print expression) calls a function
115 set print finish [on|off]
117 This controls whether the `finish' command will display the value
118 that is returned by the current function. When `off', the value is
119 still entered into the value history, but it is not printed. The
124 Allows deeply nested structures to be simplified when printing by
125 replacing deeply nested parts (beyond the max-depth) with ellipses.
126 The default max-depth is 20, but this can be set to unlimited to get
127 the old behavior back.
129 set logging debugredirect [on|off]
130 By default, GDB debug output will go to both the terminal and the logfile.
131 Set if you want debug output to go only to the log file.
133 set style title foreground COLOR
134 set style title background COLOR
135 set style title intensity VALUE
136 Control the styling of titles.
138 set style highlight foreground COLOR
139 set style highlight background COLOR
140 set style highlight intensity VALUE
141 Control the styling of highlightings.
143 maint set test-settings KIND
144 maint show test-settings KIND
145 A set of commands used by the testsuite for exercising the settings
148 set print frame-info [short-location|location|location-and-address
149 |source-and-location|source-line|auto]
150 show print frame-info
151 This controls what frame information is printed by the commands printing
152 a frame. This setting will e.g. influence the behaviour of 'backtrace',
153 'frame', 'stepi'. The python frame filtering also respect this setting.
154 The 'backtrace' '-frame-info' option can override this global setting.
159 The "help" command uses the title style to enhance the
160 readibility of its output by styling the classes and
164 Similarly to "help", the "apropos" command also uses the
165 title style for the command names. "apropos" accepts now
166 a flag "-v" (verbose) to show the full documentation
167 of matching commands and to use the highlight style to mark
168 the documentation parts matching REGEXP.
172 The GDB printf and eval commands can now print C-style and Ada-style
173 string convenience variables without calling functions in the program.
174 This allows to do formatted printing of strings without having
175 a running inferior, or when debugging a core dump.
177 info sources [-dirname | -basename] [--] [REGEXP]
178 This command has now optional arguments to only print the files
179 whose names match REGEXP. The arguments -dirname and -basename
180 allow to restrict matching respectively to the dirname and basename
184 The "show style" and its subcommands are now styling
185 a style name in their output using its own style, to help
186 the user visualize the different styles.
188 set print frame-arguments
189 The new value 'presence' indicates to only indicate the presence of
190 arguments using ..., instead of printing argument names and values.
192 set print raw-frame-arguments
193 show print raw-frame-arguments
195 These commands replace the similarly-named "set/show print raw
196 frame-arguments" commands (now with a dash instead of a space). The
197 old commands are now deprecated and may be removed in a future
200 maint test-options require-delimiter
201 maint test-options unknown-is-error
202 maint test-options unknown-is-operand
203 maint show test-options-completion-result
204 Commands used by the testsuite to validate the command options
207 focus, winheight, +, -, >, <
208 These commands are now case-sensitive.
210 * New command options, command completion
212 GDB now has a standard infrastructure to support dash-style command
213 options ('-OPT'). One benefit is that commands that use it can
214 easily support completion of command line arguments. Try "CMD
215 -[TAB]" or "help CMD" to find options supported by a command. Over
216 time, we intend to migrate most commands to this infrastructure. A
217 number of commands got support for new command options in this
220 ** The "print" and "compile print" commands now support a number of
221 options that allow overriding relevant global print settings as
222 set by "set print" subcommands:
226 -array-indexes [on|off]
227 -elements NUMBER|unlimited
231 -repeats NUMBER|unlimited
232 -static-members [on|off]
237 Note that because the "print"/"compile print" commands accept
238 arbitrary expressions which may look like options (including
239 abbreviations), if you specify any command option, then you must
240 use a double dash ("--") to mark the end of argument processing.
242 ** The "backtrace" command now supports a number of options that
243 allow overriding relevant global print settings as set by "set
244 backtrace" and "set print" subcommands:
246 -entry-values no|only|preferred|if-needed|both|compact|default
247 -frame-arguments all|scalars|none
248 -raw-frame-arguments [on|off]
249 -frame-info auto|source-line|location|source-and-location
250 |location-and-address|short-location
254 In addition, the full/no-filters/hide qualifiers are now also
255 exposed as command options too:
261 ** The "frame apply", "tfaas" and "faas" commands similarly now
262 support the following options:
267 ** The new "info sources" options -dirname and -basename options
268 are using the standard '-OPT' infrastructure.
270 All options above can also be abbreviated. The argument of boolean
271 (on/off) options can be 0/1 too, and also the argument is assumed
272 "on" if omitted. This allows writing compact command invocations,
275 (gdb) p -r -p -o 0 -- *myptr
277 The above is equivalent to:
279 (gdb) print -raw -pretty -object off -- *myptr
281 ** The "info types" command now supports the '-q' flag to disable
282 printing of some header information in a similar fashion to "info
283 variables" and "info functions".
285 ** The "info variables", "info functions", and "whereis" commands
286 now take a '-n' flag that excludes non-debug symbols (symbols
287 from the symbol table, not from the debug info such as DWARF)
290 * Completion improvements
292 ** GDB can now complete the options of the "thread apply all" and
293 "taas" commands, and their "-ascending" option can now be
296 ** GDB can now complete the options of the "info threads", "info
297 functions", "info variables", "info locals", and "info args"
300 ** GDB can now complete the options of the "compile file" and
301 "compile code" commands. The "compile file" command now
302 completes on filenames.
304 ** GDB can now complete the backtrace command's
305 "full/no-filters/hide" qualifiers.
307 * In settings, you can now abbreviate "unlimited".
309 E.g., "set print elements u" is now equivalent to "set print
315 This lists all the possible completions for the rest of the line, if it
316 were to be given as a command itself. This is intended for use by MI
317 frontends in cases when separate CLI and MI channels cannot be used.
319 -catch-throw, -catch-rethrow, and -catch-catch
320 These can be used to catch C++ exceptions in a similar fashion to
321 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
325 ** The default version of the MI interpreter is now 3 (-i=mi3).
327 ** The output of information about multi-location breakpoints (which is
328 syntactically incorrect in MI 2) has changed in MI 3. This affects
329 the following commands and events:
333 - =breakpoint-created
334 - =breakpoint-modified
336 The -fix-multi-location-breakpoint-output command can be used to enable
337 this behavior with previous MI versions.
339 ** Backtraces and frames include a new optional field addr_flags which is
340 given after the addr field. On AArch64 this contains PAC if the address
341 has been masked in the frame. On all other targets the field is not
346 The testsuite now creates the files gdb.cmd (containing the arguments
347 used to launch GDB) and gdb.in (containing all the commands sent to
348 GDB) in the output directory for each test script. Multiple invocations
349 are appended with .1, .2, .3 etc.
351 * Building GDB and GDBserver now requires GNU make >= 3.82.
353 Using another implementation of the make program or an earlier version of
354 GNU make to build GDB or GDBserver is not supported.
356 * Building GDB now requires GNU readline >= 7.0.
358 GDB now bundles GNU readline 8.0, but if you choose to use
359 --with-system-readline, only readline >= 7.0 can be used.
361 * The TUI SingleKey keymap is now named "SingleKey". This can be used
362 from .inputrc to bind keys in this keymap. This feature is only
363 available when gdb is built against GNU readline 8.0 or later.
365 * Removed targets and native configurations
367 GDB no longer supports debugging the Cell Broadband Engine. This includes
368 both debugging standalone Cell/B.E. SPU applications and integrated debugging
369 of Cell/B.E. applications that use both the PPU and SPU architectures.
375 *** Changes in GDB 8.3
377 * GDB and GDBserver now support access to additional registers on
378 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
381 * GDB now has experimental support for the compilation and injection of
382 C++ source code into the inferior. This beta release does not include
383 support for several language features, such as templates, constructors,
386 This feature requires GCC 7.1 or higher built with libcp1.so
389 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
390 can be passed using the '[ADDRESS]:PORT' notation, or the regular
391 'ADDRESS:PORT' method.
393 * DWARF index cache: GDB can now automatically save indices of DWARF
394 symbols on disk to speed up further loading of the same binaries.
396 * Ada task switching is now supported on aarch64-elf targets when
397 debugging a program using the Ravenscar Profile. For more information,
398 see the "Tasking Support when using the Ravenscar Profile" section
399 in the GDB user manual.
401 * GDB in batch mode now exits with status 1 if the last command to be
404 * The RISC-V target now supports target descriptions.
406 * System call catchpoints now support system call aliases on FreeBSD.
407 When the ABI of a system call changes in FreeBSD, this is
408 implemented by leaving a compatibility system call using the old ABI
409 at the existing number and allocating a new system call number for
410 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
411 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
412 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
413 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
414 so that a system call catchpoint for the 'kevent' system call will
415 catch invocations of both the 'kevent' and 'freebsd11_kevent'
416 binaries. This ensures that 'kevent' system calls are caught for
417 binaries using either the old or new ABIs.
419 * Terminal styling is now available for the CLI and the TUI. GNU
420 Source Highlight can additionally be used to provide styling of
421 source code snippets. See the "set style" commands, below, for more
424 * Removed support for old demangling styles arm, edg, gnu, hp and
429 set debug compile-cplus-types
430 show debug compile-cplus-types
431 Control the display of debug output about type conversion in the
432 C++ compile feature. Commands have no effect while compiliong
437 Control whether debug output about files/functions skipping is
440 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
441 Apply a command to some frames.
442 FLAG arguments allow to control what output to produce and how to handle
443 errors raised when applying COMMAND to a frame.
446 Apply a command to all threads (ignoring errors and empty output).
447 Shortcut for 'thread apply all -s COMMAND'.
450 Apply a command to all frames (ignoring errors and empty output).
451 Shortcut for 'frame apply all -s COMMAND'.
454 Apply a command to all frames of all threads (ignoring errors and empty
456 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
458 maint set dwarf unwinders (on|off)
459 maint show dwarf unwinders
460 Control whether DWARF unwinders can be used.
463 Display a list of open files for a process.
467 Changes to the "frame", "select-frame", and "info frame" CLI commands.
468 These commands all now take a frame specification which
469 is either a frame level, or one of the keywords 'level', 'address',
470 'function', or 'view' followed by a parameter. Selecting a frame by
471 address, or viewing a frame outside the current backtrace now
472 requires the use of a keyword. Selecting a frame by level is
473 unchanged. The MI comment "-stack-select-frame" is unchanged.
475 target remote FILENAME
476 target extended-remote FILENAME
477 If FILENAME is a Unix domain socket, GDB will attempt to connect
478 to this socket instead of opening FILENAME as a character device.
480 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
481 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
482 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
483 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
484 These commands can now print only the searched entities
485 matching the provided regexp(s), giving a condition
486 on the entity names or entity types. The flag -q disables
487 printing headers or informations messages.
493 These commands now determine the syntax for the shown entities
494 according to the language chosen by `set language'. In particular,
495 `set language auto' means to automatically choose the language of
498 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
499 The 'thread apply' command accepts new FLAG arguments.
500 FLAG arguments allow to control what output to produce and how to handle
501 errors raised when applying COMMAND to a thread.
503 set tui tab-width NCHARS
504 show tui tab-width NCHARS
505 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
507 set style enabled [on|off]
509 Enable or disable terminal styling. Styling is enabled by default
510 on most hosts, but disabled by default when in batch mode.
512 set style sources [on|off]
514 Enable or disable source code styling. Source code styling is
515 enabled by default, but only takes effect if styling in general is
516 enabled, and if GDB was linked with GNU Source Highlight.
518 set style filename foreground COLOR
519 set style filename background COLOR
520 set style filename intensity VALUE
521 Control the styling of file names.
523 set style function foreground COLOR
524 set style function background COLOR
525 set style function intensity VALUE
526 Control the styling of function names.
528 set style variable foreground COLOR
529 set style variable background COLOR
530 set style variable intensity VALUE
531 Control the styling of variable names.
533 set style address foreground COLOR
534 set style address background COLOR
535 set style address intensity VALUE
536 Control the styling of addresses.
540 ** The '-data-disassemble' MI command now accepts an '-a' option to
541 disassemble the whole function surrounding the given program
542 counter value or function name. Support for this feature can be
543 verified by using the "-list-features" command, which should
544 contain "data-disassemble-a-option".
546 ** Command responses and notifications that include a frame now include
547 the frame's architecture in a new "arch" attribute.
549 * New native configurations
551 GNU/Linux/RISC-V riscv*-*-linux*
552 FreeBSD/riscv riscv*-*-freebsd*
556 GNU/Linux/RISC-V riscv*-*-linux*
558 CSKY GNU/LINUX csky*-*-linux
559 FreeBSD/riscv riscv*-*-freebsd*
561 GNU/Linux/OpenRISC or1k*-*-linux*
565 GDB no longer supports native debugging on versions of MS-Windows
570 ** GDB no longer supports Python versions less than 2.6.
572 ** The gdb.Inferior type has a new 'progspace' property, which is the program
573 space associated to that inferior.
575 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
576 of objfiles associated to that program space.
578 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
579 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
582 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
583 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
584 correct and did not work properly.
586 ** The gdb.Value type has a new constructor, which is used to construct a
587 gdb.Value from a Python buffer object and a gdb.Type.
593 Enable or disable the undefined behavior sanitizer. This is
594 disabled by default, but passing --enable-ubsan=yes or
595 --enable-ubsan=auto to configure will enable it. Enabling this can
596 cause a performance penalty. The undefined behavior sanitizer was
597 first introduced in GCC 4.9.
599 *** Changes in GDB 8.2
601 * The 'set disassembler-options' command now supports specifying options
604 * The 'symbol-file' command now accepts an '-o' option to add a relative
605 offset to all sections.
607 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
608 a relative offset to all sections, but it allows to override the load
609 address of individual sections using '-s'.
611 * The 'add-symbol-file' command no longer requires the second argument
612 (address of the text section).
614 * The endianness used with the 'set endian auto' mode in the absence of
615 an executable selected for debugging is now the last endianness chosen
616 either by one of the 'set endian big' and 'set endian little' commands
617 or by inferring from the last executable used, rather than the startup
620 * The pager now allows a "c" response, meaning to disable the pager
621 for the rest of the current command.
623 * The commands 'info variables/functions/types' now show the source line
624 numbers of symbol definitions when available.
626 * 'info proc' now works on running processes on FreeBSD systems and core
627 files created on FreeBSD systems.
629 * C expressions can now use _Alignof, and C++ expressions can now use
632 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
633 the vector length while the process is running.
639 Control display of debugging info regarding the FreeBSD native target.
641 set|show varsize-limit
642 This new setting allows the user to control the maximum size of Ada
643 objects being printed when those objects have a variable type,
644 instead of that maximum size being hardcoded to 65536 bytes.
646 set|show record btrace cpu
647 Controls the processor to be used for enabling errata workarounds for
650 maint check libthread-db
651 Run integrity checks on the current inferior's thread debugging
654 maint set check-libthread-db (on|off)
655 maint show check-libthread-db
656 Control whether to run integrity checks on inferior specific thread
657 debugging libraries as they are loaded. The default is not to
662 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
664 ** The commands attached to a breakpoint can be set by assigning to
665 the breakpoint's "commands" field.
667 ** gdb.execute can now execute multi-line gdb commands.
669 ** The new functions gdb.convenience_variable and
670 gdb.set_convenience_variable can be used to get and set the value
671 of convenience variables.
673 ** A gdb.Parameter will no longer print the "set" help text on an
674 ordinary "set"; instead by default a "set" will be silent unless
675 the get_set_string method returns a non-empty string.
679 RiscV ELF riscv*-*-elf
681 * Removed targets and native configurations
683 m88k running OpenBSD m88*-*-openbsd*
684 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
685 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
686 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
688 * Aarch64/Linux hardware watchpoints improvements
690 Hardware watchpoints on unaligned addresses are now properly
691 supported when running Linux kernel 4.10 or higher: read and access
692 watchpoints are no longer spuriously missed, and all watchpoints
693 lengths between 1 and 8 bytes are supported. On older kernels,
694 watchpoints set on unaligned addresses are no longer missed, with
695 the tradeoff that there is a possibility of false hits being
700 --enable-codesign=CERT
701 This can be used to invoke "codesign -s CERT" after building gdb.
702 This option is useful on macOS, where code signing is required for
703 gdb to work properly.
705 --disable-gdbcli has been removed
706 This is now silently accepted, but does nothing.
708 *** Changes in GDB 8.1
710 * GDB now supports dynamically creating arbitrary register groups specified
711 in XML target descriptions. This allows for finer grain grouping of
712 registers on systems with a large amount of registers.
714 * The 'ptype' command now accepts a '/o' flag, which prints the
715 offsets and sizes of fields in a struct, like the pahole(1) tool.
717 * New "--readnever" command line option instructs GDB to not read each
718 symbol file's symbolic debug information. This makes startup faster
719 but at the expense of not being able to perform symbolic debugging.
720 This option is intended for use cases where symbolic debugging will
721 not be used, e.g., when you only need to dump the debuggee's core.
723 * GDB now uses the GNU MPFR library, if available, to emulate target
724 floating-point arithmetic during expression evaluation when the target
725 uses different floating-point formats than the host. At least version
726 3.1 of GNU MPFR is required.
728 * GDB now supports access to the guarded-storage-control registers and the
729 software-based guarded-storage broadcast control registers on IBM z14.
731 * On Unix systems, GDB now supports transmitting environment variables
732 that are to be set or unset to GDBserver. These variables will
733 affect the environment to be passed to the remote inferior.
735 To inform GDB of environment variables that are to be transmitted to
736 GDBserver, use the "set environment" command. Only user set
737 environment variables are sent to GDBserver.
739 To inform GDB of environment variables that are to be unset before
740 the remote inferior is started by the GDBserver, use the "unset
741 environment" command.
743 * Completion improvements
745 ** GDB can now complete function parameters in linespecs and
746 explicit locations without quoting. When setting breakpoints,
747 quoting around functions names to help with TAB-completion is
748 generally no longer necessary. For example, this now completes
751 (gdb) b function(in[TAB]
752 (gdb) b function(int)
754 Related, GDB is no longer confused with completing functions in
755 C++ anonymous namespaces:
758 (gdb) b (anonymous namespace)::[TAB][TAB]
759 (anonymous namespace)::a_function()
760 (anonymous namespace)::b_function()
762 ** GDB now has much improved linespec and explicit locations TAB
763 completion support, that better understands what you're
764 completing and offers better suggestions. For example, GDB no
765 longer offers data symbols as possible completions when you're
766 setting a breakpoint.
768 ** GDB now TAB-completes label symbol names.
770 ** The "complete" command now mimics TAB completion accurately.
772 * New command line options (gcore)
775 Dump all memory mappings.
777 * Breakpoints on C++ functions are now set on all scopes by default
779 By default, breakpoints on functions/methods are now interpreted as
780 specifying all functions with the given name ignoring missing
781 leading scopes (namespaces and classes).
783 For example, assuming a C++ program with symbols named:
788 both commands "break func()" and "break B::func()" set a breakpoint
791 You can use the new flag "-qualified" to override this. This makes
792 GDB interpret the specified function name as a complete
793 fully-qualified name instead. For example, using the same C++
794 program, the "break -q B::func" command sets a breakpoint on
795 "B::func", only. A parameter has been added to the Python
796 gdb.Breakpoint constructor to achieve the same result when creating
797 a breakpoint from Python.
799 * Breakpoints on functions marked with C++ ABI tags
801 GDB can now set breakpoints on functions marked with C++ ABI tags
802 (e.g., [abi:cxx11]). See here for a description of ABI tags:
803 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
805 Functions with a C++11 abi tag are demangled/displayed like this:
807 function[abi:cxx11](int)
810 You can now set a breakpoint on such functions simply as if they had
813 (gdb) b function(int)
815 Or if you need to disambiguate between tags, like:
817 (gdb) b function[abi:other_tag](int)
819 Tab completion was adjusted accordingly as well.
823 ** New events gdb.new_inferior, gdb.inferior_deleted, and
824 gdb.new_thread are emitted. See the manual for further
825 description of these.
827 ** A new function, "gdb.rbreak" has been added to the Python API.
828 This function allows the setting of a large number of breakpoints
829 via a regex pattern in Python. See the manual for further details.
831 ** Python breakpoints can now accept explicit locations. See the
832 manual for a further description of this feature.
835 * New features in the GDB remote stub, GDBserver
837 ** GDBserver is now able to start inferior processes with a
838 specified initial working directory.
840 The user can set the desired working directory to be used from
841 GDB using the new "set cwd" command.
843 ** New "--selftest" command line option runs some GDBserver self
844 tests. These self tests are disabled in releases.
846 ** On Unix systems, GDBserver now does globbing expansion and variable
847 substitution in inferior command line arguments.
849 This is done by starting inferiors using a shell, like GDB does.
850 See "set startup-with-shell" in the user manual for how to disable
851 this from GDB when using "target extended-remote". When using
852 "target remote", you can disable the startup with shell by using the
853 new "--no-startup-with-shell" GDBserver command line option.
855 ** On Unix systems, GDBserver now supports receiving environment
856 variables that are to be set or unset from GDB. These variables
857 will affect the environment to be passed to the inferior.
859 * When catching an Ada exception raised with a message, GDB now prints
860 the message in the catchpoint hit notification. In GDB/MI mode, that
861 information is provided as an extra field named "exception-message"
862 in the *stopped notification.
864 * Trait objects can now be inspected When debugging Rust code. This
865 requires compiler support which will appear in Rust 1.24.
869 QEnvironmentHexEncoded
870 Inform GDBserver of an environment variable that is to be passed to
871 the inferior when starting it.
874 Inform GDBserver of an environment variable that is to be unset
875 before starting the remote inferior.
878 Inform GDBserver that the environment should be reset (i.e.,
879 user-set environment variables should be unset).
882 Indicates whether the inferior must be started with a shell or not.
885 Tell GDBserver that the inferior to be started should use a specific
888 * The "maintenance print c-tdesc" command now takes an optional
889 argument which is the file name of XML target description.
891 * The "maintenance selftest" command now takes an optional argument to
892 filter the tests to be run.
894 * The "enable", and "disable" commands now accept a range of
895 breakpoint locations, e.g. "enable 1.3-5".
900 Set and show the current working directory for the inferior.
903 Set and show compilation command used for compiling and injecting code
904 with the 'compile' commands.
906 set debug separate-debug-file
907 show debug separate-debug-file
908 Control the display of debug output about separate debug file search.
910 set dump-excluded-mappings
911 show dump-excluded-mappings
912 Control whether mappings marked with the VM_DONTDUMP flag should be
913 dumped when generating a core file.
916 List the registered selftests.
919 Start the debugged program stopping at the first instruction.
922 Control display of debugging messages related to OpenRISC targets.
924 set|show print type nested-type-limit
925 Set and show the limit of nesting level for nested types that the
926 type printer will show.
928 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
931 * Safer/improved support for debugging with no debug info
933 GDB no longer assumes functions with no debug information return
936 This means that GDB now refuses to call such functions unless you
937 tell it the function's type, by either casting the call to the
938 declared return type, or by casting the function to a function
939 pointer of the right type, and calling that:
941 (gdb) p getenv ("PATH")
942 'getenv' has unknown return type; cast the call to its declared return type
943 (gdb) p (char *) getenv ("PATH")
944 $1 = 0x7fffffffe "/usr/local/bin:/"...
945 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
946 $2 = 0x7fffffffe "/usr/local/bin:/"...
948 Similarly, GDB no longer assumes that global variables with no debug
949 info have type 'int', and refuses to print the variable's value
950 unless you tell it the variable's type:
953 'var' has unknown type; cast it to its declared type
957 * New native configurations
959 FreeBSD/aarch64 aarch64*-*-freebsd*
960 FreeBSD/arm arm*-*-freebsd*
964 FreeBSD/aarch64 aarch64*-*-freebsd*
965 FreeBSD/arm arm*-*-freebsd*
966 OpenRISC ELF or1k*-*-elf
968 * Removed targets and native configurations
970 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
972 *** Changes in GDB 8.0
974 * GDB now supports access to the PKU register on GNU/Linux. The register is
975 added by the Memory Protection Keys for Userspace feature which will be
976 available in future Intel CPUs.
978 * GDB now supports C++11 rvalue references.
982 ** New functions to start, stop and access a running btrace recording.
983 ** Rvalue references are now supported in gdb.Type.
985 * GDB now supports recording and replaying rdrand and rdseed Intel 64
988 * Building GDB and GDBserver now requires a C++11 compiler.
990 For example, GCC 4.8 or later.
992 It is no longer possible to build GDB or GDBserver with a C
993 compiler. The --disable-build-with-cxx configure option has been
996 * Building GDB and GDBserver now requires GNU make >= 3.81.
998 It is no longer supported to build GDB or GDBserver with another
999 implementation of the make program or an earlier version of GNU make.
1001 * Native debugging on MS-Windows supports command-line redirection
1003 Command-line arguments used for starting programs on MS-Windows can
1004 now include redirection symbols supported by native Windows shells,
1005 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1006 as "run", "start", and "set args", as well as the corresponding MI
1009 * Support for thread names on MS-Windows.
1011 GDB now catches and handles the special exception that programs
1012 running on MS-Windows use to assign names to threads in the
1015 * Support for Java programs compiled with gcj has been removed.
1017 * User commands now accept an unlimited number of arguments.
1018 Previously, only up to 10 was accepted.
1020 * The "eval" command now expands user-defined command arguments.
1022 This makes it easier to process a variable number of arguments:
1027 eval "print $arg%d", $i
1032 * Target descriptions can now describe registers for sparc32 and sparc64.
1034 * GDB now supports DWARF version 5 (debug information format).
1035 Its .debug_names index is not yet supported.
1037 * New native configurations
1039 FreeBSD/mips mips*-*-freebsd
1043 Synopsys ARC arc*-*-elf32
1044 FreeBSD/mips mips*-*-freebsd
1046 * Removed targets and native configurations
1048 Alpha running FreeBSD alpha*-*-freebsd*
1049 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1054 Erases all the flash memory regions reported by the target.
1056 maint print arc arc-instruction address
1057 Print internal disassembler information about instruction at a given address.
1061 set disassembler-options
1062 show disassembler-options
1063 Controls the passing of target specific information to the disassembler.
1064 If it is necessary to specify more than one disassembler option then
1065 multiple options can be placed together into a comma separated list.
1066 The default value is the empty string. Currently, the only supported
1067 targets are ARM, PowerPC and S/390.
1072 Erases all the flash memory regions reported by the target. This is
1073 equivalent to the CLI command flash-erase.
1075 -file-list-shared-libraries
1076 List the shared libraries in the program. This is
1077 equivalent to the CLI command "info shared".
1080 Catchpoints stopping the program when Ada exceptions are
1081 handled. This is equivalent to the CLI command "catch handlers".
1083 *** Changes in GDB 7.12
1085 * GDB and GDBserver now build with a C++ compiler by default.
1087 The --enable-build-with-cxx configure option is now enabled by
1088 default. One must now explicitly configure with
1089 --disable-build-with-cxx in order to build with a C compiler. This
1090 option will be removed in a future release.
1092 * GDBserver now supports recording btrace without maintaining an active
1095 * GDB now supports a negative repeat count in the 'x' command to examine
1096 memory backward from the given address. For example:
1099 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1100 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1101 (gdb) x/-5i 0x0000000000400580
1102 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1103 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1104 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1105 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1106 0x40057b <main(int, char**)+25>:
1107 callq 0x400536 <Func1(int, char const*)>
1109 * Fortran: Support structures with fields of dynamic types and
1110 arrays of dynamic types.
1112 * The symbol dumping maintenance commands have new syntax.
1113 maint print symbols [-pc address] [--] [filename]
1114 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1115 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1116 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1117 maint print msymbols [-objfile objfile] [--] [filename]
1119 * GDB now supports multibit bitfields and enums in target register
1122 * New Python-based convenience function $_as_string(val), which returns
1123 the textual representation of a value. This function is especially
1124 useful to obtain the text label of an enum value.
1126 * Intel MPX bound violation handling.
1128 Segmentation faults caused by a Intel MPX boundary violation
1129 now display the kind of violation (upper or lower), the memory
1130 address accessed and the memory bounds, along with the usual
1131 signal received and code location.
1135 Program received signal SIGSEGV, Segmentation fault
1136 Upper bound violation while accessing address 0x7fffffffc3b3
1137 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1138 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1140 * Rust language support.
1141 GDB now supports debugging programs written in the Rust programming
1142 language. See https://www.rust-lang.org/ for more information about
1145 * Support for running interpreters on specified input/output devices
1147 GDB now supports a new mechanism that allows frontends to provide
1148 fully featured GDB console views, as a better alternative to
1149 building such views on top of the "-interpreter-exec console"
1150 command. See the new "new-ui" command below. With that command,
1151 frontends can now start GDB in the traditional command-line mode
1152 running in an embedded terminal emulator widget, and create a
1153 separate MI interpreter running on a specified i/o device. In this
1154 way, GDB handles line editing, history, tab completion, etc. in the
1155 console all by itself, and the GUI uses the separate MI interpreter
1156 for its own control and synchronization, invisible to the command
1159 * The "catch syscall" command catches groups of related syscalls.
1161 The "catch syscall" command now supports catching a group of related
1162 syscalls using the 'group:' or 'g:' prefix.
1167 skip -gfile file-glob-pattern
1168 skip -function function
1169 skip -rfunction regular-expression
1170 A generalized form of the skip command, with new support for
1171 glob-style file names and regular expressions for function names.
1172 Additionally, a file spec and a function spec may now be combined.
1174 maint info line-table REGEXP
1175 Display the contents of GDB's internal line table data struture.
1178 Run any GDB unit tests that were compiled in.
1181 Start a new user interface instance running INTERP as interpreter,
1182 using the TTY file for input/output.
1186 ** gdb.Breakpoint objects have a new attribute "pending", which
1187 indicates whether the breakpoint is pending.
1188 ** Three new breakpoint-related events have been added:
1189 gdb.breakpoint_created, gdb.breakpoint_modified, and
1190 gdb.breakpoint_deleted.
1192 signal-event EVENTID
1193 Signal ("set") the given MS-Windows event object. This is used in
1194 conjunction with the Windows JIT debugging (AeDebug) support, where
1195 the OS suspends a crashing process until a debugger can attach to
1196 it. Resuming the crashing process, in order to debug it, is done by
1197 signalling an event.
1199 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1200 was added in GDBserver, including JIT compiling fast tracepoint's
1201 conditional expression bytecode into native code.
1203 * Support for various remote target protocols and ROM monitors has
1206 target m32rsdi Remote M32R debugging over SDI
1207 target mips MIPS remote debugging protocol
1208 target pmon PMON ROM monitor
1209 target ddb NEC's DDB variant of PMON for Vr4300
1210 target rockhopper NEC RockHopper variant of PMON
1211 target lsi LSI variant of PMO
1213 * Support for tracepoints and fast tracepoints on powerpc-linux,
1214 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1215 including JIT compiling fast tracepoint's conditional expression
1216 bytecode into native code.
1218 * MI async record =record-started now includes the method and format used for
1219 recording. For example:
1221 =record-started,thread-group="i1",method="btrace",format="bts"
1223 * MI async record =thread-selected now includes the frame field. For example:
1225 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1229 Andes NDS32 nds32*-*-elf
1231 *** Changes in GDB 7.11
1233 * GDB now supports debugging kernel-based threads on FreeBSD.
1235 * Per-inferior thread numbers
1237 Thread numbers are now per inferior instead of global. If you're
1238 debugging multiple inferiors, GDB displays thread IDs using a
1239 qualified INF_NUM.THR_NUM form. For example:
1243 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1244 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1245 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1246 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1248 As consequence, thread numbers as visible in the $_thread
1249 convenience variable and in Python's InferiorThread.num attribute
1250 are no longer unique between inferiors.
1252 GDB now maintains a second thread ID per thread, referred to as the
1253 global thread ID, which is the new equivalent of thread numbers in
1254 previous releases. See also $_gthread below.
1256 For backwards compatibility, MI's thread IDs always refer to global
1259 * Commands that accept thread IDs now accept the qualified
1260 INF_NUM.THR_NUM form as well. For example:
1263 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1266 * In commands that accept a list of thread IDs, you can now refer to
1267 all threads of an inferior using a star wildcard. GDB accepts
1268 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1269 refer to all threads of the current inferior. For example, "info
1272 * You can use "info threads -gid" to display the global thread ID of
1275 * The new convenience variable $_gthread holds the global number of
1278 * The new convenience variable $_inferior holds the number of the
1281 * GDB now displays the ID and name of the thread that hit a breakpoint
1282 or received a signal, if your program is multi-threaded. For
1285 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1286 Thread 1 "main" received signal SIGINT, Interrupt.
1288 * Record btrace now supports non-stop mode.
1290 * Support for tracepoints on aarch64-linux was added in GDBserver.
1292 * The 'record instruction-history' command now indicates speculative execution
1293 when using the Intel Processor Trace recording format.
1295 * GDB now allows users to specify explicit locations, bypassing
1296 the linespec parser. This feature is also available to GDB/MI
1299 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1300 GDB now is able to debug both AArch64 applications and ARM applications
1303 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1304 including JIT compiling fast tracepoint's conditional expression bytecode
1307 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1309 * "info threads", "info inferiors", "info display", "info checkpoints"
1310 and "maint info program-spaces" now list the corresponding items in
1311 ascending ID order, for consistency with all other "info" commands.
1313 * In Ada, the overloads selection menu has been enhanced to display the
1314 parameter types and the return types for the matching overloaded subprograms.
1318 maint set target-non-stop (on|off|auto)
1319 maint show target-non-stop
1320 Control whether GDB targets always operate in non-stop mode even if
1321 "set non-stop" is "off". The default is "auto", meaning non-stop
1322 mode is enabled if supported by the target.
1324 maint set bfd-sharing
1325 maint show bfd-sharing
1326 Control the reuse of bfd objects.
1329 show debug bfd-cache
1330 Control display of debugging info regarding bfd caching.
1334 Control display of debugging info regarding FreeBSD threads.
1336 set remote multiprocess-extensions-packet
1337 show remote multiprocess-extensions-packet
1338 Set/show the use of the remote protocol multiprocess extensions.
1340 set remote thread-events
1341 show remote thread-events
1342 Set/show the use of thread create/exit events.
1344 set ada print-signatures on|off
1345 show ada print-signatures"
1346 Control whether parameter types and return types are displayed in overloads
1347 selection menus. It is activaled (@code{on}) by default.
1351 Controls the maximum size of memory, in bytes, that GDB will
1352 allocate for value contents. Prevents incorrect programs from
1353 causing GDB to allocate overly large buffers. Default is 64k.
1355 * The "disassemble" command accepts a new modifier: /s.
1356 It prints mixed source+disassembly like /m with two differences:
1357 - disassembled instructions are now printed in program order, and
1358 - and source for all relevant files is now printed.
1359 The "/m" option is now considered deprecated: its "source-centric"
1360 output hasn't proved useful in practice.
1362 * The "record instruction-history" command accepts a new modifier: /s.
1363 It behaves exactly like /m and prints mixed source+disassembly.
1365 * The "set scheduler-locking" command supports a new mode "replay".
1366 It behaves like "off" in record mode and like "on" in replay mode.
1368 * Support for various ROM monitors has been removed:
1370 target dbug dBUG ROM monitor for Motorola ColdFire
1371 target picobug Motorola picobug monitor
1372 target dink32 DINK32 ROM monitor for PowerPC
1373 target m32r Renesas M32R/D ROM monitor
1374 target mon2000 mon2000 ROM monitor
1375 target ppcbug PPCBUG ROM monitor for PowerPC
1377 * Support for reading/writing memory and extracting values on architectures
1378 whose memory is addressable in units of any integral multiple of 8 bits.
1381 Allows to break when an Ada exception is handled.
1383 * New remote packets
1386 Indicates that an exec system call was executed.
1388 exec-events feature in qSupported
1389 The qSupported packet allows GDB to request support for exec
1390 events using the new 'gdbfeature' exec-event, and the qSupported
1391 response can contain the corresponding 'stubfeature'. Set and
1392 show commands can be used to display whether these features are enabled.
1395 Equivalent to interrupting with the ^C character, but works in
1398 thread created stop reason (T05 create:...)
1399 Indicates that the thread was just created and is stopped at entry.
1401 thread exit stop reply (w exitcode;tid)
1402 Indicates that the thread has terminated.
1405 Enables/disables thread create and exit event reporting. For
1406 example, this is used in non-stop mode when GDB stops a set of
1407 threads and synchronously waits for the their corresponding stop
1408 replies. Without exit events, if one of the threads exits, GDB
1409 would hang forever not knowing that it should no longer expect a
1410 stop for that same thread.
1413 Indicates that there are no resumed threads left in the target (all
1414 threads are stopped). The remote stub reports support for this stop
1415 reply to GDB's qSupported query.
1418 Enables/disables catching syscalls from the inferior process.
1419 The remote stub reports support for this packet to GDB's qSupported query.
1421 syscall_entry stop reason
1422 Indicates that a syscall was just called.
1424 syscall_return stop reason
1425 Indicates that a syscall just returned.
1427 * Extended-remote exec events
1429 ** GDB now has support for exec events on extended-remote Linux targets.
1430 For such targets with Linux kernels 2.5.46 and later, this enables
1431 follow-exec-mode and exec catchpoints.
1433 set remote exec-event-feature-packet
1434 show remote exec-event-feature-packet
1435 Set/show the use of the remote exec event feature.
1437 * Thread names in remote protocol
1439 The reply to qXfer:threads:read may now include a name attribute for each
1442 * Target remote mode fork and exec events
1444 ** GDB now has support for fork and exec events on target remote mode
1445 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1446 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1447 fork and exec catchpoints.
1449 * Remote syscall events
1451 ** GDB now has support for catch syscall on remote Linux targets,
1452 currently enabled on x86/x86_64 architectures.
1454 set remote catch-syscall-packet
1455 show remote catch-syscall-packet
1456 Set/show the use of the remote catch syscall feature.
1460 ** The -var-set-format command now accepts the zero-hexadecimal
1461 format. It outputs data in hexadecimal format with zero-padding on the
1466 ** gdb.InferiorThread objects have a new attribute "global_num",
1467 which refers to the thread's global thread ID. The existing
1468 "num" attribute now refers to the thread's per-inferior number.
1469 See "Per-inferior thread numbers" above.
1470 ** gdb.InferiorThread objects have a new attribute "inferior", which
1471 is the Inferior object the thread belongs to.
1473 *** Changes in GDB 7.10
1475 * Support for process record-replay and reverse debugging on aarch64*-linux*
1476 targets has been added. GDB now supports recording of A64 instruction set
1477 including advance SIMD instructions.
1479 * Support for Sun's version of the "stabs" debug file format has been removed.
1481 * GDB now honors the content of the file /proc/PID/coredump_filter
1482 (PID is the process ID) on GNU/Linux systems. This file can be used
1483 to specify the types of memory mappings that will be included in a
1484 corefile. For more information, please refer to the manual page of
1485 "core(5)". GDB also has a new command: "set use-coredump-filter
1486 on|off". It allows to set whether GDB will read the content of the
1487 /proc/PID/coredump_filter file when generating a corefile.
1489 * The "info os" command on GNU/Linux can now display information on
1491 "info os cpus" Listing of all cpus/cores on the system
1493 * GDB has two new commands: "set serial parity odd|even|none" and
1494 "show serial parity". These allows to set or show parity for the
1497 * The "info source" command now displays the producer string if it was
1498 present in the debug info. This typically includes the compiler version
1499 and may include things like its command line arguments.
1501 * The "info dll", an alias of the "info sharedlibrary" command,
1502 is now available on all platforms.
1504 * Directory names supplied to the "set sysroot" commands may be
1505 prefixed with "target:" to tell GDB to access shared libraries from
1506 the target system, be it local or remote. This replaces the prefix
1507 "remote:". The default sysroot has been changed from "" to
1508 "target:". "remote:" is automatically converted to "target:" for
1509 backward compatibility.
1511 * The system root specified by "set sysroot" will be prepended to the
1512 filename of the main executable (if reported to GDB as absolute by
1513 the operating system) when starting processes remotely, and when
1514 attaching to already-running local or remote processes.
1516 * GDB now supports automatic location and retrieval of executable
1517 files from remote targets. Remote debugging can now be initiated
1518 using only a "target remote" or "target extended-remote" command
1519 (no "set sysroot" or "file" commands are required). See "New remote
1522 * The "dump" command now supports verilog hex format.
1524 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1526 * On GNU/Linux, GDB and gdbserver are now able to access executable
1527 and shared library files without a "set sysroot" command when
1528 attaching to processes running in different mount namespaces from
1529 the debugger. This makes it possible to attach to processes in
1530 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1531 See "New remote packets" below.
1533 * The "tui reg" command now provides completion for all of the
1534 available register groups, including target specific groups.
1536 * The HISTSIZE environment variable is no longer read when determining
1537 the size of GDB's command history. GDB now instead reads the dedicated
1538 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1539 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1544 ** Memory ports can now be unbuffered.
1548 ** gdb.Objfile objects have a new attribute "username",
1549 which is the name of the objfile as specified by the user,
1550 without, for example, resolving symlinks.
1551 ** You can now write frame unwinders in Python.
1552 ** gdb.Type objects have a new method "optimized_out",
1553 returning optimized out gdb.Value instance of this type.
1554 ** gdb.Value objects have new methods "reference_value" and
1555 "const_value" which return a reference to the value and a
1556 "const" version of the value respectively.
1560 maint print symbol-cache
1561 Print the contents of the symbol cache.
1563 maint print symbol-cache-statistics
1564 Print statistics of symbol cache usage.
1566 maint flush-symbol-cache
1567 Flush the contents of the symbol cache.
1571 Start branch trace recording using Branch Trace Store (BTS) format.
1574 Evaluate expression by using the compiler and print result.
1578 Explicit commands for enabling and disabling tui mode.
1581 set mpx bound on i386 and amd64
1582 Support for bound table investigation on Intel MPX enabled applications.
1586 Start branch trace recording using Intel Processor Trace format.
1589 Print information about branch tracing internals.
1591 maint btrace packet-history
1592 Print the raw branch tracing data.
1594 maint btrace clear-packet-history
1595 Discard the stored raw branch tracing data.
1598 Discard all branch tracing data. It will be fetched and processed
1599 anew by the next "record" command.
1604 Renamed from "set debug dwarf2-die".
1605 show debug dwarf-die
1606 Renamed from "show debug dwarf2-die".
1608 set debug dwarf-read
1609 Renamed from "set debug dwarf2-read".
1610 show debug dwarf-read
1611 Renamed from "show debug dwarf2-read".
1613 maint set dwarf always-disassemble
1614 Renamed from "maint set dwarf2 always-disassemble".
1615 maint show dwarf always-disassemble
1616 Renamed from "maint show dwarf2 always-disassemble".
1618 maint set dwarf max-cache-age
1619 Renamed from "maint set dwarf2 max-cache-age".
1620 maint show dwarf max-cache-age
1621 Renamed from "maint show dwarf2 max-cache-age".
1623 set debug dwarf-line
1624 show debug dwarf-line
1625 Control display of debugging info regarding DWARF line processing.
1628 show max-completions
1629 Set the maximum number of candidates to be considered during
1630 completion. The default value is 200. This limit allows GDB
1631 to avoid generating large completion lists, the computation of
1632 which can cause the debugger to become temporarily unresponsive.
1634 set history remove-duplicates
1635 show history remove-duplicates
1636 Control the removal of duplicate history entries.
1638 maint set symbol-cache-size
1639 maint show symbol-cache-size
1640 Control the size of the symbol cache.
1642 set|show record btrace bts buffer-size
1643 Set and show the size of the ring buffer used for branch tracing in
1645 The obtained size may differ from the requested size. Use "info
1646 record" to see the obtained buffer size.
1648 set debug linux-namespaces
1649 show debug linux-namespaces
1650 Control display of debugging info regarding Linux namespaces.
1652 set|show record btrace pt buffer-size
1653 Set and show the size of the ring buffer used for branch tracing in
1654 Intel Processor Trace format.
1655 The obtained size may differ from the requested size. Use "info
1656 record" to see the obtained buffer size.
1658 maint set|show btrace pt skip-pad
1659 Set and show whether PAD packets are skipped when computing the
1662 * The command 'thread apply all' can now support new option '-ascending'
1663 to call its specified command for all threads in ascending order.
1665 * Python/Guile scripting
1667 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1668 special section named `.debug_gdb_scripts'.
1670 * New remote packets
1672 qXfer:btrace-conf:read
1673 Return the branch trace configuration for the current thread.
1675 Qbtrace-conf:bts:size
1676 Set the requested ring buffer size for branch tracing in BTS format.
1679 Enable Intel Procesor Trace-based branch tracing for the current
1680 process. The remote stub reports support for this packet to GDB's
1683 Qbtrace-conf:pt:size
1684 Set the requested ring buffer size for branch tracing in Intel Processor
1688 Indicates a memory breakpoint instruction was executed, irrespective
1689 of whether it was GDB that planted the breakpoint or the breakpoint
1690 is hardcoded in the program. This is required for correct non-stop
1694 Indicates the target stopped for a hardware breakpoint. This is
1695 required for correct non-stop mode operation.
1698 Return information about files on the remote system.
1700 qXfer:exec-file:read
1701 Return the full absolute name of the file that was executed to
1702 create a process running on the remote system.
1705 Select the filesystem on which vFile: operations with filename
1706 arguments will operate. This is required for GDB to be able to
1707 access files on remote targets where the remote stub does not
1708 share a common filesystem with the inferior(s).
1711 Indicates that a fork system call was executed.
1714 Indicates that a vfork system call was executed.
1716 vforkdone stop reason
1717 Indicates that a vfork child of the specified process has executed
1718 an exec or exit, allowing the vfork parent to resume execution.
1720 fork-events and vfork-events features in qSupported
1721 The qSupported packet allows GDB to request support for fork and
1722 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1723 and the qSupported response can contain the corresponding
1724 'stubfeatures'. Set and show commands can be used to display
1725 whether these features are enabled.
1727 * Extended-remote fork events
1729 ** GDB now has support for fork events on extended-remote Linux
1730 targets. For targets with Linux kernels 2.5.60 and later, this
1731 enables follow-fork-mode and detach-on-fork for both fork and
1732 vfork, as well as fork and vfork catchpoints.
1734 * The info record command now shows the recording format and the
1735 branch tracing configuration for the current thread when using
1736 the btrace record target.
1737 For the BTS format, it shows the ring buffer size.
1739 * GDB now has support for DTrace USDT (Userland Static Defined
1740 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1742 * GDB now supports access to vector registers on S/390 GNU/Linux
1745 * Removed command line options
1747 -xdb HP-UX XDB compatibility mode.
1749 * Removed targets and native configurations
1751 HP/PA running HP-UX hppa*-*-hpux*
1752 Itanium running HP-UX ia64-*-hpux*
1754 * New configure options
1757 This configure option allows the user to build GDB with support for
1758 Intel Processor Trace (default: auto). This requires libipt.
1760 --with-libipt-prefix=PATH
1761 Specify the path to the version of libipt that GDB should use.
1762 $PATH/include should contain the intel-pt.h header and
1763 $PATH/lib should contain the libipt.so library.
1765 *** Changes in GDB 7.9.1
1769 ** Xmethods can now specify a result type.
1771 *** Changes in GDB 7.9
1773 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1777 ** You can now access frame registers from Python scripts.
1778 ** New attribute 'producer' for gdb.Symtab objects.
1779 ** gdb.Objfile objects have a new attribute "progspace",
1780 which is the gdb.Progspace object of the containing program space.
1781 ** gdb.Objfile objects have a new attribute "owner".
1782 ** gdb.Objfile objects have a new attribute "build_id",
1783 which is the build ID generated when the file was built.
1784 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1785 ** A new event "gdb.clear_objfiles" has been added, triggered when
1786 selecting a new file to debug.
1787 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1788 ** New function gdb.lookup_objfile.
1790 New events which are triggered when GDB modifies the state of the
1793 ** gdb.events.inferior_call_pre: Function call is about to be made.
1794 ** gdb.events.inferior_call_post: Function call has just been made.
1795 ** gdb.events.memory_changed: A memory location has been altered.
1796 ** gdb.events.register_changed: A register has been altered.
1798 * New Python-based convenience functions:
1800 ** $_caller_is(name [, number_of_frames])
1801 ** $_caller_matches(regexp [, number_of_frames])
1802 ** $_any_caller_is(name [, number_of_frames])
1803 ** $_any_caller_matches(regexp [, number_of_frames])
1805 * GDB now supports the compilation and injection of source code into
1806 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1807 to compile the source code to object code, and if successful, inject
1808 and execute that code within the current context of the inferior.
1809 Currently the C language is supported. The commands used to
1810 interface with this new feature are:
1812 compile code [-raw|-r] [--] [source code]
1813 compile file [-raw|-r] filename
1817 demangle [-l language] [--] name
1818 Demangle "name" in the specified language, or the current language
1819 if elided. This command is renamed from the "maint demangle" command.
1820 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1821 as "maint demangler-warning".
1823 queue-signal signal-name-or-number
1824 Queue a signal to be delivered to the thread when it is resumed.
1826 add-auto-load-scripts-directory directory
1827 Add entries to the list of directories from which to load auto-loaded
1830 maint print user-registers
1831 List all currently available "user" registers.
1833 compile code [-r|-raw] [--] [source code]
1834 Compile, inject, and execute in the inferior the executable object
1835 code produced by compiling the provided source code.
1837 compile file [-r|-raw] filename
1838 Compile and inject into the inferior the executable object code
1839 produced by compiling the source code stored in the filename
1842 * On resume, GDB now always passes the signal the program had stopped
1843 for to the thread the signal was sent to, even if the user changed
1844 threads before resuming. Previously GDB would often (but not
1845 always) deliver the signal to the thread that happens to be current
1848 * Conversely, the "signal" command now consistently delivers the
1849 requested signal to the current thread. GDB now asks for
1850 confirmation if the program had stopped for a signal and the user
1851 switched threads meanwhile.
1853 * "breakpoint always-inserted" modes "off" and "auto" merged.
1855 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1856 won't remove breakpoints from the target until all threads stop,
1857 even in non-stop mode. The "auto" mode has been removed, and "off"
1858 is now the default mode.
1862 set debug symbol-lookup
1863 show debug symbol-lookup
1864 Control display of debugging info regarding symbol lookup.
1868 ** The -list-thread-groups command outputs an exit-code field for
1869 inferiors that have exited.
1873 MIPS SDE mips*-sde*-elf*
1877 Support for these obsolete configurations has been removed.
1879 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1880 SGI Irix-5.x mips-*-irix5*
1881 SGI Irix-6.x mips-*-irix6*
1882 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1883 VAX running Ultrix vax-*-ultrix*
1885 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1886 and "assf"), have been removed. Use the "sharedlibrary" command, or
1887 its alias "share", instead.
1889 *** Changes in GDB 7.8
1891 * New command line options
1894 This is an alias for the --data-directory option.
1896 * GDB supports printing and modifying of variable length automatic arrays
1897 as specified in ISO C99.
1899 * The ARM simulator now supports instruction level tracing
1900 with or without disassembly.
1904 GDB now has support for scripting using Guile. Whether this is
1905 available is determined at configure time.
1906 Guile version 2.0 or greater is required.
1907 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1909 * New commands (for set/show, see "New options" below)
1913 Invoke CODE by passing it to the Guile interpreter.
1917 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1919 info auto-load guile-scripts [regexp]
1920 Print the list of automatically loaded Guile scripts.
1922 * The source command is now capable of sourcing Guile scripts.
1923 This feature is dependent on the debugger being built with Guile support.
1927 set print symbol-loading (off|brief|full)
1928 show print symbol-loading
1929 Control whether to print informational messages when loading symbol
1930 information for a file. The default is "full", but when debugging
1931 programs with large numbers of shared libraries the amount of output
1932 becomes less useful.
1934 set guile print-stack (none|message|full)
1935 show guile print-stack
1936 Show a stack trace when an error is encountered in a Guile script.
1938 set auto-load guile-scripts (on|off)
1939 show auto-load guile-scripts
1940 Control auto-loading of Guile script files.
1942 maint ada set ignore-descriptive-types (on|off)
1943 maint ada show ignore-descriptive-types
1944 Control whether the debugger should ignore descriptive types in Ada
1945 programs. The default is not to ignore the descriptive types. See
1946 the user manual for more details on descriptive types and the intended
1947 usage of this option.
1949 set auto-connect-native-target
1951 Control whether GDB is allowed to automatically connect to the
1952 native target for the run, attach, etc. commands when not connected
1953 to any target yet. See also "target native" below.
1955 set record btrace replay-memory-access (read-only|read-write)
1956 show record btrace replay-memory-access
1957 Control what memory accesses are allowed during replay.
1959 maint set target-async (on|off)
1960 maint show target-async
1961 This controls whether GDB targets operate in synchronous or
1962 asynchronous mode. Normally the default is asynchronous, if it is
1963 available; but this can be changed to more easily debug problems
1964 occurring only in synchronous mode.
1966 set mi-async (on|off)
1968 Control whether MI asynchronous mode is preferred. This supersedes
1969 "set target-async" of previous GDB versions.
1971 * "set target-async" is deprecated as a CLI option and is now an alias
1972 for "set mi-async" (only puts MI into async mode).
1974 * Background execution commands (e.g., "c&", "s&", etc.) are now
1975 possible ``out of the box'' if the target supports them. Previously
1976 the user would need to explicitly enable the possibility with the
1977 "set target-async on" command.
1979 * New features in the GDB remote stub, GDBserver
1981 ** New option --debug-format=option1[,option2,...] allows one to add
1982 additional text to each output. At present only timestamps
1983 are supported: --debug-format=timestamps.
1984 Timestamps can also be turned on with the
1985 "monitor set debug-format timestamps" command from GDB.
1987 * The 'record instruction-history' command now starts counting instructions
1988 at one. This also affects the instruction ranges reported by the
1989 'record function-call-history' command when given the /i modifier.
1991 * The command 'record function-call-history' supports a new modifier '/c' to
1992 indent the function names based on their call stack depth.
1993 The fields for the '/i' and '/l' modifier have been reordered.
1994 The source line range is now prefixed with 'at'.
1995 The instruction range is now prefixed with 'inst'.
1996 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1997 "record instruction-history" and "list" commands.
1999 * The ranges given as arguments to the 'record function-call-history' and
2000 'record instruction-history' commands are now inclusive.
2002 * The btrace record target now supports the 'record goto' command.
2003 For locations inside the execution trace, the back trace is computed
2004 based on the information stored in the execution trace.
2006 * The btrace record target supports limited reverse execution and replay.
2007 The target does not record data and therefore does not allow reading
2008 memory or registers.
2010 * The "catch syscall" command now works on s390*-linux* targets.
2012 * The "compare-sections" command is no longer specific to target
2013 remote. It now works with all targets.
2015 * All native targets are now consistently called "native".
2016 Consequently, the "target child", "target GNU", "target djgpp",
2017 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2018 commands have been replaced with "target native". The QNX/NTO port
2019 leaves the "procfs" target in place and adds a "native" target for
2020 consistency with other ports. The impact on users should be minimal
2021 as these commands previously either throwed an error, or were
2022 no-ops. The target's name is visible in the output of the following
2023 commands: "help target", "info target", "info files", "maint print
2026 * The "target native" command now connects to the native target. This
2027 can be used to launch native programs even when "set
2028 auto-connect-native-target" is set to off.
2030 * GDB now supports access to Intel MPX registers on GNU/Linux.
2032 * Support for Intel AVX-512 registers on GNU/Linux.
2033 Support displaying and modifying Intel AVX-512 registers
2034 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2036 * New remote packets
2038 qXfer:btrace:read's annex
2039 The qXfer:btrace:read packet supports a new annex 'delta' to read
2040 branch trace incrementally.
2044 ** Valid Python operations on gdb.Value objects representing
2045 structs/classes invoke the corresponding overloaded operators if
2047 ** New `Xmethods' feature in the Python API. Xmethods are
2048 additional methods or replacements for existing methods of a C++
2049 class. This feature is useful for those cases where a method
2050 defined in C++ source code could be inlined or optimized out by
2051 the compiler, making it unavailable to GDB.
2054 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2056 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2057 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2058 its alias "share", instead.
2060 * The commands "set remotebaud" and "show remotebaud" are no longer
2061 supported. Use "set serial baud" and "show serial baud" (respectively)
2066 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2067 target-async". The latter is left as a deprecated alias of the
2068 former for backward compatibility. If the target supports it,
2069 CLI background execution commands are now always possible by
2070 default, independently of whether the frontend stated a
2071 preference for asynchronous execution with "-gdb-set mi-async".
2072 Previously "-gdb-set target-async off" affected both MI execution
2073 commands and CLI execution commands.
2075 *** Changes in GDB 7.7
2077 * Improved support for process record-replay and reverse debugging on
2078 arm*-linux* targets. Support for thumb32 and syscall instruction
2079 recording has been added.
2081 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2083 * GDB now supports Fission DWP file format version 2.
2084 http://gcc.gnu.org/wiki/DebugFission
2086 * New convenience function "$_isvoid", to check whether an expression
2087 is void. A void expression is an expression where the type of the
2088 result is "void". For example, some convenience variables may be
2089 "void" when evaluated (e.g., "$_exitcode" before the execution of
2090 the program being debugged; or an undefined convenience variable).
2091 Another example, when calling a function whose return type is
2094 * The "maintenance print objfiles" command now takes an optional regexp.
2096 * The "catch syscall" command now works on arm*-linux* targets.
2098 * GDB now consistently shows "<not saved>" when printing values of
2099 registers the debug info indicates have not been saved in the frame
2100 and there's nowhere to retrieve them from
2101 (callee-saved/call-clobbered registers):
2106 (gdb) info registers rax
2109 Before, the former would print "<optimized out>", and the latter
2110 "*value not available*".
2112 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2117 ** Frame filters and frame decorators have been added.
2118 ** Temporary breakpoints are now supported.
2119 ** Line tables representation has been added.
2120 ** New attribute 'parent_type' for gdb.Field objects.
2121 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2122 ** New attribute 'name' for gdb.Type objects.
2126 Nios II ELF nios2*-*-elf
2127 Nios II GNU/Linux nios2*-*-linux
2128 Texas Instruments MSP430 msp430*-*-elf
2130 * Removed native configurations
2132 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2133 been removed. ELF variants of these configurations are kept supported.
2135 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2136 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2137 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2138 i[34567]86-*-openbsd3.[0-3]
2139 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2140 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2141 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2145 Like "catch throw", but catches a re-thrown exception.
2146 maint check-psymtabs
2147 Renamed from old "maint check-symtabs".
2149 Perform consistency checks on symtabs.
2150 maint expand-symtabs
2151 Expand symtabs matching an optional regexp.
2154 Display the details of GDB configure-time options.
2156 maint set|show per-command
2157 maint set|show per-command space
2158 maint set|show per-command time
2159 maint set|show per-command symtab
2160 Enable display of per-command gdb resource usage.
2162 remove-symbol-file FILENAME
2163 remove-symbol-file -a ADDRESS
2164 Remove a symbol file added via add-symbol-file. The file to remove
2165 can be identified by its filename or by an address that lies within
2166 the boundaries of this symbol file in memory.
2169 info exceptions REGEXP
2170 Display the list of Ada exceptions defined in the program being
2171 debugged. If provided, only the exceptions whose names match REGEXP
2176 set debug symfile off|on
2178 Control display of debugging info regarding reading symbol files and
2179 symbol tables within those files
2181 set print raw frame-arguments
2182 show print raw frame-arguments
2183 Set/show whether to print frame arguments in raw mode,
2184 disregarding any defined pretty-printers.
2186 set remote trace-status-packet
2187 show remote trace-status-packet
2188 Set/show the use of remote protocol qTStatus packet.
2192 Control display of debugging messages related to Nios II targets.
2196 Control whether target-assisted range stepping is enabled.
2198 set startup-with-shell
2199 show startup-with-shell
2200 Specifies whether Unix child processes are started via a shell or
2205 Use the target memory cache for accesses to the code segment. This
2206 improves performance of remote debugging (particularly disassembly).
2208 * You can now use a literal value 'unlimited' for options that
2209 interpret 0 or -1 as meaning "unlimited". E.g., "set
2210 trace-buffer-size unlimited" is now an alias for "set
2211 trace-buffer-size -1" and "set height unlimited" is now an alias for
2214 * The "set debug symtab-create" debugging option of GDB has been changed to
2215 accept a verbosity level. 0 means "off", 1 provides basic debugging
2216 output, and values of 2 or greater provides more verbose output.
2218 * New command-line options
2220 Display the details of GDB configure-time options.
2222 * The command 'tsave' can now support new option '-ctf' to save trace
2223 buffer in Common Trace Format.
2225 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2228 * GDB now implements the the C++ 'typeid' operator.
2230 * The new convenience variable $_exception holds the exception being
2231 thrown or caught at an exception-related catchpoint.
2233 * The exception-related catchpoints, like "catch throw", now accept a
2234 regular expression which can be used to filter exceptions by type.
2236 * The new convenience variable $_exitsignal is automatically set to
2237 the terminating signal number when the program being debugged dies
2238 due to an uncaught signal.
2242 ** All MI commands now accept an optional "--language" option.
2243 Support for this feature can be verified by using the "-list-features"
2244 command, which should contain "language-option".
2246 ** The new command -info-gdb-mi-command allows the user to determine
2247 whether a GDB/MI command is supported or not.
2249 ** The "^error" result record returned when trying to execute an undefined
2250 GDB/MI command now provides a variable named "code" whose content is the
2251 "undefined-command" error code. Support for this feature can be verified
2252 by using the "-list-features" command, which should contain
2253 "undefined-command-error-code".
2255 ** The -trace-save MI command can optionally save trace buffer in Common
2258 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2260 ** The command -data-list-register-values now accepts an optional
2261 "--skip-unavailable" option. When used, only the available registers
2264 ** The new command -trace-frame-collected dumps collected variables,
2265 computed expressions, tvars, memory and registers in a traceframe.
2267 ** The commands -stack-list-locals, -stack-list-arguments and
2268 -stack-list-variables now accept an option "--skip-unavailable".
2269 When used, only the available locals or arguments are displayed.
2271 ** The -exec-run command now accepts an optional "--start" option.
2272 When used, the command follows the same semantics as the "start"
2273 command, stopping the program's execution at the start of its
2274 main subprogram. Support for this feature can be verified using
2275 the "-list-features" command, which should contain
2276 "exec-run-start-option".
2278 ** The new commands -catch-assert and -catch-exceptions insert
2279 catchpoints stopping the program when Ada exceptions are raised.
2281 ** The new command -info-ada-exceptions provides the equivalent of
2282 the new "info exceptions" command.
2284 * New system-wide configuration scripts
2285 A GDB installation now provides scripts suitable for use as system-wide
2286 configuration scripts for the following systems:
2290 * GDB now supports target-assigned range stepping with remote targets.
2291 This improves the performance of stepping source lines by reducing
2292 the number of control packets from/to GDB. See "New remote packets"
2295 * GDB now understands the element 'tvar' in the XML traceframe info.
2296 It has the id of the collected trace state variables.
2298 * On S/390 targets that provide the transactional-execution feature,
2299 the program interruption transaction diagnostic block (TDB) is now
2300 represented as a number of additional "registers" in GDB.
2302 * New remote packets
2306 The vCont packet supports a new 'r' action, that tells the remote
2307 stub to step through an address range itself, without GDB
2308 involvemement at each single-step.
2310 qXfer:libraries-svr4:read's annex
2311 The previously unused annex of the qXfer:libraries-svr4:read packet
2312 is now used to support passing an argument list. The remote stub
2313 reports support for this argument list to GDB's qSupported query.
2314 The defined arguments are "start" and "prev", used to reduce work
2315 necessary for library list updating, resulting in significant
2318 * New features in the GDB remote stub, GDBserver
2320 ** GDBserver now supports target-assisted range stepping. Currently
2321 enabled on x86/x86_64 GNU/Linux targets.
2323 ** GDBserver now adds element 'tvar' in the XML in the reply to
2324 'qXfer:traceframe-info:read'. It has the id of the collected
2325 trace state variables.
2327 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2330 * New 'z' formatter for printing and examining memory, this displays the
2331 value as hexadecimal zero padded on the left to the size of the type.
2333 * GDB can now use Windows x64 unwinding data.
2335 * The "set remotebaud" command has been replaced by "set serial baud".
2336 Similarly, "show remotebaud" has been replaced by "show serial baud".
2337 The "set remotebaud" and "show remotebaud" commands are still available
2338 to provide backward compatibility with older versions of GDB.
2340 *** Changes in GDB 7.6
2342 * Target record has been renamed to record-full.
2343 Record/replay is now enabled with the "record full" command.
2344 This also affects settings that are associated with full record/replay
2345 that have been moved from "set/show record" to "set/show record full":
2347 set|show record full insn-number-max
2348 set|show record full stop-at-limit
2349 set|show record full memory-query
2351 * A new record target "record-btrace" has been added. The new target
2352 uses hardware support to record the control-flow of a process. It
2353 does not support replaying the execution, but it implements the
2354 below new commands for investigating the recorded execution log.
2355 This new recording method can be enabled using:
2359 The "record-btrace" target is only available on Intel Atom processors
2360 and requires a Linux kernel 2.6.32 or later.
2362 * Two new commands have been added for record/replay to give information
2363 about the recorded execution without having to replay the execution.
2364 The commands are only supported by "record btrace".
2366 record instruction-history prints the execution history at
2367 instruction granularity
2369 record function-call-history prints the execution history at
2370 function granularity
2372 * New native configurations
2374 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2375 FreeBSD/powerpc powerpc*-*-freebsd
2376 x86_64/Cygwin x86_64-*-cygwin*
2377 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2381 ARM AArch64 aarch64*-*-elf
2382 ARM AArch64 GNU/Linux aarch64*-*-linux
2383 Lynx 178 PowerPC powerpc-*-lynx*178
2384 x86_64/Cygwin x86_64-*-cygwin*
2385 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2387 * If the configured location of system.gdbinit file (as given by the
2388 --with-system-gdbinit option at configure time) is in the
2389 data-directory (as specified by --with-gdb-datadir at configure
2390 time) or in one of its subdirectories, then GDB will look for the
2391 system-wide init file in the directory specified by the
2392 --data-directory command-line option.
2394 * New command line options:
2396 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2397 other initialization files, unlike -nx which disables all of them.
2399 * Removed command line options
2401 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2404 * The 'ptype' and 'whatis' commands now accept an argument to control
2407 * 'info proc' now works on some core files.
2411 ** Vectors can be created with gdb.Type.vector.
2413 ** Python's atexit.register now works in GDB.
2415 ** Types can be pretty-printed via a Python API.
2417 ** Python 3 is now supported (in addition to Python 2.4 or later)
2419 ** New class gdb.Architecture exposes GDB's internal representation
2420 of architecture in the Python API.
2422 ** New method Frame.architecture returns the gdb.Architecture object
2423 corresponding to the frame's architecture.
2425 * New Python-based convenience functions:
2427 ** $_memeq(buf1, buf2, length)
2428 ** $_streq(str1, str2)
2430 ** $_regex(str, regex)
2432 * The 'cd' command now defaults to using '~' (the home directory) if not
2435 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2436 default for GCC since November 2000.
2438 * The command 'forward-search' can now be abbreviated as 'fo'.
2440 * The command 'info tracepoints' can now display 'installed on target'
2441 or 'not installed on target' for each non-pending location of tracepoint.
2443 * New configure options
2445 --enable-libmcheck/--disable-libmcheck
2446 By default, development versions are built with -lmcheck on hosts
2447 that support it, in order to help track memory corruption issues.
2448 Release versions, on the other hand, are built without -lmcheck
2449 by default. The --enable-libmcheck/--disable-libmcheck configure
2450 options allow the user to override that default.
2451 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2452 This configure option allows the user to build GDB with
2453 libbabeltrace using which GDB can read Common Trace Format data.
2455 * New commands (for set/show, see "New options" below)
2458 Catch signals. This is similar to "handle", but allows commands and
2459 conditions to be attached.
2462 List the BFDs known to GDB.
2464 python-interactive [command]
2466 Start a Python interactive prompt, or evaluate the optional command
2467 and print the result of expressions.
2470 "py" is a new alias for "python".
2472 enable type-printer [name]...
2473 disable type-printer [name]...
2474 Enable or disable type printers.
2478 ** For the Renesas Super-H architecture, the "regs" command has been removed
2479 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2484 set print type methods (on|off)
2485 show print type methods
2486 Control whether method declarations are displayed by "ptype".
2487 The default is to show them.
2489 set print type typedefs (on|off)
2490 show print type typedefs
2491 Control whether typedef definitions are displayed by "ptype".
2492 The default is to show them.
2494 set filename-display basename|relative|absolute
2495 show filename-display
2496 Control the way in which filenames is displayed.
2497 The default is "relative", which preserves previous behavior.
2499 set trace-buffer-size
2500 show trace-buffer-size
2501 Request target to change the size of trace buffer.
2503 set remote trace-buffer-size-packet auto|on|off
2504 show remote trace-buffer-size-packet
2505 Control the use of the remote protocol `QTBuffer:size' packet.
2509 Control display of debugging messages related to ARM AArch64.
2512 set debug coff-pe-read
2513 show debug coff-pe-read
2514 Control display of debugging messages related to reading of COFF/PE
2519 Control display of debugging messages related to Mach-O symbols
2522 set debug notification
2523 show debug notification
2524 Control display of debugging info for async remote notification.
2528 ** Command parameter changes are now notified using new async record
2529 "=cmd-param-changed".
2530 ** Trace frame changes caused by command "tfind" are now notified using
2531 new async record "=traceframe-changed".
2532 ** The creation, deletion and modification of trace state variables
2533 are now notified using new async records "=tsv-created",
2534 "=tsv-deleted" and "=tsv-modified".
2535 ** The start and stop of process record are now notified using new
2536 async record "=record-started" and "=record-stopped".
2537 ** Memory changes are now notified using new async record
2539 ** The data-disassemble command response will include a "fullname" field
2540 containing the absolute file name when source has been requested.
2541 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2542 command, to allow pattern filling of memory areas.
2543 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2544 library load/unload events.
2545 ** The response to breakpoint commands and breakpoint async records
2546 includes an "installed" field containing a boolean state about each
2547 non-pending tracepoint location is whether installed on target or not.
2548 ** Output of the "-trace-status" command includes a "trace-file" field
2549 containing the name of the trace file being examined. This field is
2550 optional, and only present when examining a trace file.
2551 ** The "fullname" field is now always present along with the "file" field,
2552 even if the file cannot be found by GDB.
2554 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2555 You must have the LZMA library available when configuring GDB for this
2556 feature to be enabled. For more information, see:
2557 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2559 * New remote packets
2562 Set the size of trace buffer. The remote stub reports support for this
2563 packet to gdb's qSupported query.
2566 Enable Branch Trace Store (BTS)-based branch tracing for the current
2567 thread. The remote stub reports support for this packet to gdb's
2571 Disable branch tracing for the current thread. The remote stub reports
2572 support for this packet to gdb's qSupported query.
2575 Read the traced branches for the current thread. The remote stub
2576 reports support for this packet to gdb's qSupported query.
2578 *** Changes in GDB 7.5
2580 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2581 for more x32 ABI info.
2583 * GDB now supports access to MIPS DSP registers on Linux targets.
2585 * GDB now supports debugging microMIPS binaries.
2587 * The "info os" command on GNU/Linux can now display information on
2588 several new classes of objects managed by the operating system:
2589 "info os procgroups" lists process groups
2590 "info os files" lists file descriptors
2591 "info os sockets" lists internet-domain sockets
2592 "info os shm" lists shared-memory regions
2593 "info os semaphores" lists semaphores
2594 "info os msg" lists message queues
2595 "info os modules" lists loaded kernel modules
2597 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2598 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2599 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2600 options and inspect the probe arguments using the new $_probe_arg family
2601 of convenience variables. You can obtain more information about SystemTap
2602 in <http://sourceware.org/systemtap/>.
2604 * GDB now supports reversible debugging on ARM, it allows you to
2605 debug basic ARM and THUMB instructions, and provides
2606 record/replay support.
2608 * The option "symbol-reloading" has been deleted as it is no longer used.
2612 ** GDB commands implemented in Python can now be put in command class
2615 ** The "maint set python print-stack on|off" is now deleted.
2617 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2618 apply "flag enum"-style pretty-printing to any enum.
2620 ** gdb.lookup_symbol can now work when there is no current frame.
2622 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2623 the source at which the symbol was defined.
2625 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2626 method 'value'. The former indicates whether the symbol needs a
2627 frame in order to compute its value, and the latter computes the
2630 ** A new method 'referenced_value' on gdb.Value objects which can
2631 dereference pointer as well as C++ reference values.
2633 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2634 which return the global and static blocks (as gdb.Block objects),
2635 of the underlying symbol table, respectively.
2637 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2638 object associated with a PC value.
2640 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2641 of the address range occupied by code for the current source line.
2643 * Go language support.
2644 GDB now supports debugging programs written in the Go programming
2647 * GDBserver now supports stdio connections.
2648 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2650 * The binary "gdbtui" can no longer be built or installed.
2651 Use "gdb -tui" instead.
2653 * GDB will now print "flag" enums specially. A flag enum is one where
2654 all the enumerator values have no bits in common when pairwise
2655 "and"ed. When printing a value whose type is a flag enum, GDB will
2656 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2657 (gdb) print (enum E) 3
2660 * The filename part of a linespec will now match trailing components
2661 of a source file name. For example, "break gcc/expr.c:1000" will
2662 now set a breakpoint in build/gcc/expr.c, but not
2663 build/libcpp/expr.c.
2665 * The "info proc" and "generate-core-file" commands will now also
2666 work on remote targets connected to GDBserver on Linux.
2668 * The command "info catch" has been removed. It has been disabled
2669 since December 2007.
2671 * The "catch exception" and "catch assert" commands now accept
2672 a condition at the end of the command, much like the "break"
2673 command does. For instance:
2675 (gdb) catch exception Constraint_Error if Barrier = True
2677 Previously, it was possible to add a condition to such catchpoints,
2678 but it had to be done as a second step, after the catchpoint had been
2679 created, using the "condition" command.
2681 * The "info static-tracepoint-marker" command will now also work on
2682 native Linux targets with in-process agent.
2684 * GDB can now set breakpoints on inlined functions.
2686 * The .gdb_index section has been updated to include symbols for
2687 inlined functions. GDB will ignore older .gdb_index sections by
2688 default, which could cause symbol files to be loaded more slowly
2689 until their .gdb_index sections can be recreated. The new command
2690 "set use-deprecated-index-sections on" will cause GDB to use any older
2691 .gdb_index sections it finds. This will restore performance, but the
2692 ability to set breakpoints on inlined functions will be lost in symbol
2693 files with older .gdb_index sections.
2695 The .gdb_index section has also been updated to record more information
2696 about each symbol. This speeds up the "info variables", "info functions"
2697 and "info types" commands when used with programs having the .gdb_index
2698 section, as well as speeding up debugging with shared libraries using
2699 the .gdb_index section.
2701 * Ada support for GDB/MI Variable Objects has been added.
2703 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2708 ** New command -info-os is the MI equivalent of "info os".
2710 ** Output logs ("set logging" and related) now include MI output.
2714 ** "set use-deprecated-index-sections on|off"
2715 "show use-deprecated-index-sections on|off"
2716 Controls the use of deprecated .gdb_index sections.
2718 ** "catch load" and "catch unload" can be used to stop when a shared
2719 library is loaded or unloaded, respectively.
2721 ** "enable count" can be used to auto-disable a breakpoint after
2724 ** "info vtbl" can be used to show the virtual method tables for
2725 C++ and Java objects.
2727 ** "explore" and its sub commands "explore value" and "explore type"
2728 can be used to recursively explore values and types of
2729 expressions. These commands are available only if GDB is
2730 configured with '--with-python'.
2732 ** "info auto-load" shows status of all kinds of auto-loaded files,
2733 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2734 sequences of commands files, "info auto-load python-scripts"
2735 shows status of auto-loading Python script files,
2736 "info auto-load local-gdbinit" shows status of loading init file
2737 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2738 status of inferior specific thread debugging shared library loading.
2740 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2741 and "show auto-load-scripts" commands have been deprecated, use their
2742 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2743 and "show auto-load python-scripts" counterparts instead.
2745 ** "dprintf location,format,args..." creates a dynamic printf, which
2746 is basically a breakpoint that does a printf and immediately
2747 resumes your program's execution, so it is like a printf that you
2748 can insert dynamically at runtime instead of at compiletime.
2750 ** "set print symbol"
2752 Controls whether GDB attempts to display the symbol, if any,
2753 corresponding to addresses it prints. This defaults to "on", but
2754 you can set it to "off" to restore GDB's previous behavior.
2756 * Deprecated commands
2758 ** For the Renesas Super-H architecture, the "regs" command has been
2759 deprecated, and "info all-registers" should be used instead.
2763 Renesas RL78 rl78-*-elf
2764 HP OpenVMS ia64 ia64-hp-openvms*
2766 * GDBserver supports evaluation of breakpoint conditions. When
2767 support is advertised by GDBserver, GDB may be told to send the
2768 breakpoint conditions in bytecode form to GDBserver. GDBserver
2769 will only report the breakpoint trigger to GDB when its condition
2774 set mips compression
2775 show mips compression
2776 Select the compressed ISA encoding used in functions that have no symbol
2777 information available. The encoding can be set to either of:
2780 and is updated automatically from ELF file flags if available.
2782 set breakpoint condition-evaluation
2783 show breakpoint condition-evaluation
2784 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2785 GDBserver ("target"). Default option "auto" chooses the most efficient
2787 This option can improve debugger efficiency depending on the speed of the
2791 Disable auto-loading globally.
2794 Show auto-loading setting of all kinds of auto-loaded files.
2796 set auto-load gdb-scripts on|off
2797 show auto-load gdb-scripts
2798 Control auto-loading of GDB canned sequences of commands files.
2800 set auto-load python-scripts on|off
2801 show auto-load python-scripts
2802 Control auto-loading of Python script files.
2804 set auto-load local-gdbinit on|off
2805 show auto-load local-gdbinit
2806 Control loading of init file (.gdbinit) from current directory.
2808 set auto-load libthread-db on|off
2809 show auto-load libthread-db
2810 Control auto-loading of inferior specific thread debugging shared library.
2812 set auto-load scripts-directory <dir1>[:<dir2>...]
2813 show auto-load scripts-directory
2814 Set a list of directories from which to load auto-loaded scripts.
2815 Automatically loaded Python scripts and GDB scripts are located in one
2816 of the directories listed by this option.
2817 The delimiter (':' above) may differ according to the host platform.
2819 set auto-load safe-path <dir1>[:<dir2>...]
2820 show auto-load safe-path
2821 Set a list of directories from which it is safe to auto-load files.
2822 The delimiter (':' above) may differ according to the host platform.
2824 set debug auto-load on|off
2825 show debug auto-load
2826 Control display of debugging info for auto-loading the files above.
2828 set dprintf-style gdb|call|agent
2830 Control the way in which a dynamic printf is performed; "gdb"
2831 requests a GDB printf command, while "call" causes dprintf to call a
2832 function in the inferior. "agent" requests that the target agent
2833 (such as GDBserver) do the printing.
2835 set dprintf-function <expr>
2836 show dprintf-function
2837 set dprintf-channel <expr>
2838 show dprintf-channel
2839 Set the function and optional first argument to the call when using
2840 the "call" style of dynamic printf.
2842 set disconnected-dprintf on|off
2843 show disconnected-dprintf
2844 Control whether agent-style dynamic printfs continue to be in effect
2845 after GDB disconnects.
2847 * New configure options
2849 --with-auto-load-dir
2850 Configure default value for the 'set auto-load scripts-directory'
2851 setting above. It defaults to '$debugdir:$datadir/auto-load',
2852 $debugdir representing global debugging info directories (available
2853 via 'show debug-file-directory') and $datadir representing GDB's data
2854 directory (available via 'show data-directory').
2856 --with-auto-load-safe-path
2857 Configure default value for the 'set auto-load safe-path' setting
2858 above. It defaults to the --with-auto-load-dir setting.
2860 --without-auto-load-safe-path
2861 Set 'set auto-load safe-path' to '/', effectively disabling this
2864 * New remote packets
2866 z0/z1 conditional breakpoints extension
2868 The z0/z1 breakpoint insertion packets have been extended to carry
2869 a list of conditional expressions over to the remote stub depending on the
2870 condition evaluation mode. The use of this extension can be controlled
2871 via the "set remote conditional-breakpoints-packet" command.
2875 Specify the signals which the remote stub may pass to the debugged
2876 program without GDB involvement.
2878 * New command line options
2880 --init-command=FILE, -ix Like --command, -x but execute it
2881 before loading inferior.
2882 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2883 execute it before loading inferior.
2885 *** Changes in GDB 7.4
2887 * GDB now handles ambiguous linespecs more consistently; the existing
2888 FILE:LINE support has been expanded to other types of linespecs. A
2889 breakpoint will now be set on all matching locations in all
2890 inferiors, and locations will be added or removed according to
2893 * GDB now allows you to skip uninteresting functions and files when
2894 stepping with the "skip function" and "skip file" commands.
2896 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2897 and "show remote hardware-watchpoint-length-limit". These allows to
2898 set or show the maximum length limit (in bytes) of a remote
2899 target hardware watchpoint.
2901 This allows e.g. to use "unlimited" hardware watchpoints with the
2902 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2903 watchpoints are slower than real hardware watchpoints but are
2904 significantly faster than gdb software watchpoints.
2908 ** The register_pretty_printer function in module gdb.printing now takes
2909 an optional `replace' argument. If True, the new printer replaces any
2912 ** The "maint set python print-stack on|off" command has been
2913 deprecated and will be deleted in GDB 7.5.
2914 A new command: "set python print-stack none|full|message" has
2915 replaced it. Additionally, the default for "print-stack" is
2916 now "message", which just prints the error message without
2919 ** A prompt substitution hook (prompt_hook) is now available to the
2922 ** A new Python module, gdb.prompt has been added to the GDB Python
2923 modules library. This module provides functionality for
2924 escape sequences in prompts (used by set/show
2925 extended-prompt). These escape sequences are replaced by their
2926 corresponding value.
2928 ** Python commands and convenience-functions located in
2929 'data-directory'/python/gdb/command and
2930 'data-directory'/python/gdb/function are now automatically loaded
2933 ** Blocks now provide four new attributes. global_block and
2934 static_block will return the global and static blocks
2935 respectively. is_static and is_global are boolean attributes
2936 that indicate if the block is one of those two types.
2938 ** Symbols now provide the "type" attribute, the type of the symbol.
2940 ** The "gdb.breakpoint" function has been deprecated in favor of
2943 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2944 of a function. This class is based on the "finish" command
2945 available in the CLI.
2947 ** Type objects for struct and union types now allow access to
2948 the fields using standard Python dictionary (mapping) methods.
2949 For example, "some_type['myfield']" now works, as does
2950 "some_type.items()".
2952 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2955 ** A new function, "deep_items" has been added to the gdb.types
2956 module in the GDB Python modules library. This function returns
2957 an iterator over the fields of a struct or union type. Unlike
2958 the standard Python "iteritems" method, it will recursively traverse
2959 any anonymous fields.
2963 ** "*stopped" events can report several new "reason"s, such as
2966 ** Breakpoint changes are now notified using new async records, like
2967 "=breakpoint-modified".
2969 ** New command -ada-task-info.
2971 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2972 $sdir specifies the default system locations of shared libraries.
2973 $pdir specifies the directory where the libpthread used by the application
2976 GDB no longer looks in $sdir and $pdir after it has searched the directories
2977 mentioned in libthread-db-search-path. If you want to search those
2978 directories, they must be specified in libthread-db-search-path.
2979 The default value of libthread-db-search-path on GNU/Linux and Solaris
2980 systems is now "$sdir:$pdir".
2982 $pdir is not supported by gdbserver, it is currently ignored.
2983 $sdir is supported by gdbserver.
2985 * New configure option --with-iconv-bin.
2986 When using the internationalization support like the one in the GNU C
2987 library, GDB will invoke the "iconv" program to get a list of supported
2988 character sets. If this program lives in a non-standard location, one can
2989 use this option to specify where to find it.
2991 * When natively debugging programs on PowerPC BookE processors running
2992 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2993 watchpoints, which specify a mask in addition to an address to watch.
2994 The mask specifies that some bits of an address (the bits which are
2995 reset in the mask) should be ignored when matching the address accessed
2996 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2997 section in the user manual for more details.
2999 * The new option --once causes GDBserver to stop listening for connections once
3000 the first connection is made. The listening port used by GDBserver will
3001 become available after that.
3003 * New commands "info macros" and "alias" have been added.
3005 * New function parameters suffix @entry specifies value of function parameter
3006 at the time the function got called. Entry values are available only since
3012 "!" is now an alias of the "shell" command.
3013 Note that no space is needed between "!" and SHELL COMMAND.
3017 watch EXPRESSION mask MASK_VALUE
3018 The watch command now supports the mask argument which allows creation
3019 of masked watchpoints, if the current architecture supports this feature.
3021 info auto-load-scripts [REGEXP]
3022 This command was formerly named "maintenance print section-scripts".
3023 It is now generally useful and is no longer a maintenance-only command.
3025 info macro [-all] [--] MACRO
3026 The info macro command has new options `-all' and `--'. The first for
3027 printing all definitions of a macro. The second for explicitly specifying
3028 the end of arguments and the beginning of the macro name in case the macro
3029 name starts with a hyphen.
3031 collect[/s] EXPRESSIONS
3032 The tracepoint collect command now takes an optional modifier "/s"
3033 that directs it to dereference pointer-to-character types and
3034 collect the bytes of memory up to a zero byte. The behavior is
3035 similar to what you see when you use the regular print command on a
3036 string. An optional integer following the "/s" sets a bound on the
3037 number of bytes that will be collected.
3040 The trace start command now interprets any supplied arguments as a
3041 note to be recorded with the trace run, with an effect similar to
3042 setting the variable trace-notes.
3045 The trace stop command now interprets any arguments as a note to be
3046 mentioned along with the tstatus report that the trace was stopped
3047 with a command. The effect is similar to setting the variable
3050 * Tracepoints can now be enabled and disabled at any time after a trace
3051 experiment has been started using the standard "enable" and "disable"
3052 commands. It is now possible to start a trace experiment with no enabled
3053 tracepoints; GDB will display a warning, but will allow the experiment to
3054 begin, assuming that tracepoints will be enabled as needed while the trace
3057 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3058 locations with 4-byte instructions, when they were previously
3059 limited to locations with instructions of 5 bytes or longer.
3063 set debug dwarf2-read
3064 show debug dwarf2-read
3065 Turns on or off display of debugging messages related to reading
3066 DWARF debug info. The default is off.
3068 set debug symtab-create
3069 show debug symtab-create
3070 Turns on or off display of debugging messages related to symbol table
3071 creation. The default is off.
3074 show extended-prompt
3075 Set the GDB prompt, and allow escape sequences to be inserted to
3076 display miscellaneous information (see 'help set extended-prompt'
3077 for the list of sequences). This prompt (and any information
3078 accessed through the escape sequences) is updated every time the
3079 prompt is displayed.
3081 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3082 show print entry-values
3083 Set printing of frame argument values at function entry. In some cases
3084 GDB can determine the value of function argument which was passed by the
3085 function caller, even if the value was modified inside the called function.
3087 set debug entry-values
3088 show debug entry-values
3089 Control display of debugging info for determining frame argument values at
3090 function entry and virtual tail call frames.
3092 set basenames-may-differ
3093 show basenames-may-differ
3094 Set whether a source file may have multiple base names.
3095 (A "base name" is the name of a file with the directory part removed.
3096 Example: The base name of "/home/user/hello.c" is "hello.c".)
3097 If set, GDB will canonicalize file names (e.g., expand symlinks)
3098 before comparing them. Canonicalization is an expensive operation,
3099 but it allows the same file be known by more than one base name.
3100 If not set (the default), all source files are assumed to have just
3101 one base name, and gdb will do file name comparisons more efficiently.
3107 Set a user name and notes for the current and any future trace runs.
3108 This is useful for long-running and/or disconnected traces, to
3109 inform others (or yourself) as to who is running the trace, supply
3110 contact information, or otherwise explain what is going on.
3112 set trace-stop-notes
3113 show trace-stop-notes
3114 Set a note attached to the trace run, that is displayed when the
3115 trace has been stopped by a tstop command. This is useful for
3116 instance as an explanation, if you are stopping a trace run that was
3117 started by someone else.
3119 * New remote packets
3123 Dynamically enable a tracepoint in a started trace experiment.
3127 Dynamically disable a tracepoint in a started trace experiment.
3131 Set the user and notes of the trace run.
3135 Query the current status of a tracepoint.
3139 Query the minimum length of instruction at which a fast tracepoint may
3142 * Dcache size (number of lines) and line-size are now runtime-configurable
3143 via "set dcache line" and "set dcache line-size" commands.
3147 Texas Instruments TMS320C6x tic6x-*-*
3151 Renesas RL78 rl78-*-elf
3153 *** Changes in GDB 7.3.1
3155 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3157 *** Changes in GDB 7.3
3159 * GDB has a new command: "thread find [REGEXP]".
3160 It finds the thread id whose name, target id, or thread extra info
3161 matches the given regular expression.
3163 * The "catch syscall" command now works on mips*-linux* targets.
3165 * The -data-disassemble MI command now supports modes 2 and 3 for
3166 dumping the instruction opcodes.
3168 * New command line options
3170 -data-directory DIR Specify DIR as the "data-directory".
3171 This is mostly for testing purposes.
3173 * The "maint set python auto-load on|off" command has been renamed to
3174 "set auto-load-scripts on|off".
3176 * GDB has a new command: "set directories".
3177 It is like the "dir" command except that it replaces the
3178 source path list instead of augmenting it.
3180 * GDB now understands thread names.
3182 On GNU/Linux, "info threads" will display the thread name as set by
3183 prctl or pthread_setname_np.
3185 There is also a new command, "thread name", which can be used to
3186 assign a name internally for GDB to display.
3189 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3190 has been integrated into GDB.
3194 ** The function gdb.Write now accepts an optional keyword 'stream'.
3195 This keyword, when provided, will direct the output to either
3196 stdout, stderr, or GDB's logging output.
3198 ** Parameters can now be be sub-classed in Python, and in particular
3199 you may implement the get_set_doc and get_show_doc functions.
3200 This improves how Parameter set/show documentation is processed
3201 and allows for more dynamic content.
3203 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3204 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3205 have an is_valid method.
3207 ** Breakpoints can now be sub-classed in Python, and in particular
3208 you may implement a 'stop' function that is executed each time
3209 the inferior reaches that breakpoint.
3211 ** New function gdb.lookup_global_symbol looks up a global symbol.
3213 ** GDB values in Python are now callable if the value represents a
3214 function. For example, if 'some_value' represents a function that
3215 takes two integer parameters and returns a value, you can call
3216 that function like so:
3218 result = some_value (10,20)
3220 ** Module gdb.types has been added.
3221 It contains a collection of utilities for working with gdb.Types objects:
3222 get_basic_type, has_field, make_enum_dict.
3224 ** Module gdb.printing has been added.
3225 It contains utilities for writing and registering pretty-printers.
3226 New classes: PrettyPrinter, SubPrettyPrinter,
3227 RegexpCollectionPrettyPrinter.
3228 New function: register_pretty_printer.
3230 ** New commands "info pretty-printers", "enable pretty-printer" and
3231 "disable pretty-printer" have been added.
3233 ** gdb.parameter("directories") is now available.
3235 ** New function gdb.newest_frame returns the newest frame in the
3238 ** The gdb.InferiorThread class has a new "name" attribute. This
3239 holds the thread's name.
3241 ** Python Support for Inferior events.
3242 Python scripts can add observers to be notified of events
3243 occurring in the process being debugged.
3244 The following events are currently supported:
3245 - gdb.events.cont Continue event.
3246 - gdb.events.exited Inferior exited event.
3247 - gdb.events.stop Signal received, and Breakpoint hit events.
3251 ** GDB now puts template parameters in scope when debugging in an
3252 instantiation. For example, if you have:
3254 template<int X> int func (void) { return X; }
3256 then if you step into func<5>, "print X" will show "5". This
3257 feature requires proper debuginfo support from the compiler; it
3258 was added to GCC 4.5.
3260 ** The motion commands "next", "finish", "until", and "advance" now
3261 work better when exceptions are thrown. In particular, GDB will
3262 no longer lose control of the inferior; instead, the GDB will
3263 stop the inferior at the point at which the exception is caught.
3264 This functionality requires a change in the exception handling
3265 code that was introduced in GCC 4.5.
3267 * GDB now follows GCC's rules on accessing volatile objects when
3268 reading or writing target state during expression evaluation.
3269 One notable difference to prior behavior is that "print x = 0"
3270 no longer generates a read of x; the value of the assignment is
3271 now always taken directly from the value being assigned.
3273 * GDB now has some support for using labels in the program's source in
3274 linespecs. For instance, you can use "advance label" to continue
3275 execution to a label.
3277 * GDB now has support for reading and writing a new .gdb_index
3278 section. This section holds a fast index of DWARF debugging
3279 information and can be used to greatly speed up GDB startup and
3280 operation. See the documentation for `save gdb-index' for details.
3282 * The "watch" command now accepts an optional "-location" argument.
3283 When used, this causes GDB to watch the memory referred to by the
3284 expression. Such a watchpoint is never deleted due to it going out
3287 * GDB now supports thread debugging of core dumps on GNU/Linux.
3289 GDB now activates thread debugging using the libthread_db library
3290 when debugging GNU/Linux core dumps, similarly to when debugging
3291 live processes. As a result, when debugging a core dump file, GDB
3292 is now able to display pthread_t ids of threads. For example, "info
3293 threads" shows the same output as when debugging the process when it
3294 was live. In earlier releases, you'd see something like this:
3297 * 1 LWP 6780 main () at main.c:10
3299 While now you see this:
3302 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3304 It is also now possible to inspect TLS variables when debugging core
3307 When debugging a core dump generated on a machine other than the one
3308 used to run GDB, you may need to point GDB at the correct
3309 libthread_db library with the "set libthread-db-search-path"
3310 command. See the user manual for more details on this command.
3312 * When natively debugging programs on PowerPC BookE processors running
3313 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3314 which stop execution of the inferior whenever it executes an instruction
3315 at any address within the specified range. See the "PowerPC Embedded"
3316 section in the user manual for more details.
3318 * New features in the GDB remote stub, GDBserver
3320 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3321 and i686 LynxOS (version 5.x).
3323 ** GDBserver is now supported on Blackfin Linux.
3325 * New native configurations
3327 ia64 HP-UX ia64-*-hpux*
3331 Analog Devices, Inc. Blackfin Processor bfin-*
3333 * Ada task switching is now supported on sparc-elf targets when
3334 debugging a program using the Ravenscar Profile. For more information,
3335 see the "Tasking Support when using the Ravenscar Profile" section
3336 in the GDB user manual.
3338 * Guile support was removed.
3340 * New features in the GNU simulator
3342 ** The --map-info flag lists all known core mappings.
3344 ** CFI flashes may be simulated via the "cfi" device.
3346 *** Changes in GDB 7.2
3348 * Shared library support for remote targets by default
3350 When GDB is configured for a generic, non-OS specific target, like
3351 for example, --target=arm-eabi or one of the many *-*-elf targets,
3352 GDB now queries remote stubs for loaded shared libraries using the
3353 `qXfer:libraries:read' packet. Previously, shared library support
3354 was always disabled for such configurations.
3358 ** Argument Dependent Lookup (ADL)
3360 In C++ ADL lookup directs function search to the namespaces of its
3361 arguments even if the namespace has not been imported.
3371 Here the compiler will search for `foo' in the namespace of 'b'
3372 and find A::foo. GDB now supports this. This construct is commonly
3373 used in the Standard Template Library for operators.
3375 ** Improved User Defined Operator Support
3377 In addition to member operators, GDB now supports lookup of operators
3378 defined in a namespace and imported with a `using' directive, operators
3379 defined in the global scope, operators imported implicitly from an
3380 anonymous namespace, and the ADL operators mentioned in the previous
3382 GDB now also supports proper overload resolution for all the previously
3383 mentioned flavors of operators.
3385 ** static const class members
3387 Printing of static const class members that are initialized in the
3388 class definition has been fixed.
3390 * Windows Thread Information Block access.
3392 On Windows targets, GDB now supports displaying the Windows Thread
3393 Information Block (TIB) structure. This structure is visible either
3394 by using the new command `info w32 thread-information-block' or, by
3395 dereferencing the new convenience variable named `$_tlb', a
3396 thread-specific pointer to the TIB. This feature is also supported
3397 when remote debugging using GDBserver.
3399 * Static tracepoints
3401 Static tracepoints are calls in the user program into a tracing
3402 library. One such library is a port of the LTTng kernel tracer to
3403 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3404 When debugging with GDBserver, GDB now supports combining the GDB
3405 tracepoint machinery with such libraries. For example: the user can
3406 use GDB to probe a static tracepoint marker (a call from the user
3407 program into the tracing library) with the new "strace" command (see
3408 "New commands" below). This creates a "static tracepoint" in the
3409 breakpoint list, that can be manipulated with the same feature set
3410 as fast and regular tracepoints. E.g., collect registers, local and
3411 global variables, collect trace state variables, and define
3412 tracepoint conditions. In addition, the user can collect extra
3413 static tracepoint marker specific data, by collecting the new
3414 $_sdata internal variable. When analyzing the trace buffer, you can
3415 inspect $_sdata like any other variable available to GDB. For more
3416 information, see the "Tracepoints" chapter in GDB user manual. New
3417 remote packets have been defined to support static tracepoints, see
3418 the "New remote packets" section below.
3420 * Better reconstruction of tracepoints after disconnected tracing
3422 GDB will attempt to download the original source form of tracepoint
3423 definitions when starting a trace run, and then will upload these
3424 upon reconnection to the target, resulting in a more accurate
3425 reconstruction of the tracepoints that are in use on the target.
3429 You can now exercise direct control over the ways that GDB can
3430 affect your program. For instance, you can disallow the setting of
3431 breakpoints, so that the program can run continuously (assuming
3432 non-stop mode). In addition, the "observer" variable is available
3433 to switch all of the different controls; in observer mode, GDB
3434 cannot affect the target's behavior at all, which is useful for
3435 tasks like diagnosing live systems in the field.
3437 * The new convenience variable $_thread holds the number of the
3440 * New remote packets
3444 Return the address of the Windows Thread Information Block of a given thread.
3448 In response to several of the tracepoint packets, the target may now
3449 also respond with a number of intermediate `qRelocInsn' request
3450 packets before the final result packet, to have GDB handle
3451 relocating an instruction to execute at a different address. This
3452 is particularly useful for stubs that support fast tracepoints. GDB
3453 reports support for this feature in the qSupported packet.
3457 List static tracepoint markers in the target program.
3461 List static tracepoint markers at a given address in the target
3464 qXfer:statictrace:read
3466 Read the static trace data collected (by a `collect $_sdata'
3467 tracepoint action). The remote stub reports support for this packet
3468 to gdb's qSupported query.
3472 Send the current settings of GDB's permission flags.
3476 Send part of the source (textual) form of a tracepoint definition,
3477 which includes location, conditional, and action list.
3479 * The source command now accepts a -s option to force searching for the
3480 script in the source search path even if the script name specifies
3483 * New features in the GDB remote stub, GDBserver
3485 - GDBserver now support tracepoints (including fast tracepoints, and
3486 static tracepoints). The feature is currently supported by the
3487 i386-linux and amd64-linux builds. See the "Tracepoints support
3488 in gdbserver" section in the manual for more information.
3490 GDBserver JIT compiles the tracepoint's conditional agent
3491 expression bytecode into native code whenever possible for low
3492 overhead dynamic tracepoints conditionals. For such tracepoints,
3493 an expression that examines program state is evaluated when the
3494 tracepoint is reached, in order to determine whether to capture
3495 trace data. If the condition is simple and false, processing the
3496 tracepoint finishes very quickly and no data is gathered.
3498 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3499 for static tracepoints support.
3501 - GDBserver now supports x86_64 Windows 64-bit debugging.
3503 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3504 it understands register description.
3506 * The --batch flag now disables pagination and queries.
3508 * X86 general purpose registers
3510 GDB now supports reading/writing byte, word and double-word x86
3511 general purpose registers directly. This means you can use, say,
3512 $ah or $ax to refer, respectively, to the byte register AH and
3513 16-bit word register AX that are actually portions of the 32-bit
3514 register EAX or 64-bit register RAX.
3516 * The `commands' command now accepts a range of breakpoints to modify.
3517 A plain `commands' following a command that creates multiple
3518 breakpoints affects all the breakpoints set by that command. This
3519 applies to breakpoints set by `rbreak', and also applies when a
3520 single `break' command creates multiple breakpoints (e.g.,
3521 breakpoints on overloaded c++ functions).
3523 * The `rbreak' command now accepts a filename specification as part of
3524 its argument, limiting the functions selected by the regex to those
3525 in the specified file.
3527 * Support for remote debugging Windows and SymbianOS shared libraries
3528 from Unix hosts has been improved. Non Windows GDB builds now can
3529 understand target reported file names that follow MS-DOS based file
3530 system semantics, such as file names that include drive letters and
3531 use the backslash character as directory separator. This makes it
3532 possible to transparently use the "set sysroot" and "set
3533 solib-search-path" on Unix hosts to point as host copies of the
3534 target's shared libraries. See the new command "set
3535 target-file-system-kind" described below, and the "Commands to
3536 specify files" section in the user manual for more information.
3540 eval template, expressions...
3541 Convert the values of one or more expressions under the control
3542 of the string template to a command line, and call it.
3544 set target-file-system-kind unix|dos-based|auto
3545 show target-file-system-kind
3546 Set or show the assumed file system kind for target reported file
3549 save breakpoints <filename>
3550 Save all current breakpoint definitions to a file suitable for use
3551 in a later debugging session. To read the saved breakpoint
3552 definitions, use the `source' command.
3554 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3557 info static-tracepoint-markers
3558 Display information about static tracepoint markers in the target.
3560 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3561 Define a static tracepoint by probing a marker at the given
3562 function, line, address, or marker ID.
3566 Enable and disable observer mode.
3568 set may-write-registers on|off
3569 set may-write-memory on|off
3570 set may-insert-breakpoints on|off
3571 set may-insert-tracepoints on|off
3572 set may-insert-fast-tracepoints on|off
3573 set may-interrupt on|off
3574 Set individual permissions for GDB effects on the target. Note that
3575 some of these settings can have undesirable or surprising
3576 consequences, particularly when changed in the middle of a session.
3577 For instance, disabling the writing of memory can prevent
3578 breakpoints from being inserted, cause single-stepping to fail, or
3579 even crash your program, if you disable after breakpoints have been
3580 inserted. However, GDB should not crash.
3582 set record memory-query on|off
3583 show record memory-query
3584 Control whether to stop the inferior if memory changes caused
3585 by an instruction cannot be recorded.
3590 The disassemble command now supports "start,+length" form of two arguments.
3594 ** GDB now provides a new directory location, called the python directory,
3595 where Python scripts written for GDB can be installed. The location
3596 of that directory is <data-directory>/python, where <data-directory>
3597 is the GDB data directory. For more details, see section `Scripting
3598 GDB using Python' in the manual.
3600 ** The GDB Python API now has access to breakpoints, symbols, symbol
3601 tables, program spaces, inferiors, threads and frame's code blocks.
3602 Additionally, GDB Parameters can now be created from the API, and
3603 manipulated via set/show in the CLI.
3605 ** New functions gdb.target_charset, gdb.target_wide_charset,
3606 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3608 ** New exception gdb.GdbError.
3610 ** Pretty-printers are now also looked up in the current program space.
3612 ** Pretty-printers can now be individually enabled and disabled.
3614 ** GDB now looks for names of Python scripts to auto-load in a
3615 special section named `.debug_gdb_scripts', in addition to looking
3616 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3618 * Tracepoint actions were unified with breakpoint commands. In particular,
3619 there are no longer differences in "info break" output for breakpoints and
3620 tracepoints and the "commands" command can be used for both tracepoints and
3621 regular breakpoints.
3625 ARM Symbian arm*-*-symbianelf*
3627 * D language support.
3628 GDB now supports debugging programs written in the D programming
3631 * GDB now supports the extended ptrace interface for PowerPC which is
3632 available since Linux kernel version 2.6.34. This automatically enables
3633 any hardware breakpoints and additional hardware watchpoints available in
3634 the processor. The old ptrace interface exposes just one hardware
3635 watchpoint and no hardware breakpoints.
3637 * GDB is now able to use the Data Value Compare (DVC) register available on
3638 embedded PowerPC processors to implement in hardware simple watchpoint
3639 conditions of the form:
3641 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3643 This works in native GDB running on Linux kernels with the extended ptrace
3644 interface mentioned above.
3646 *** Changes in GDB 7.1
3650 ** Namespace Support
3652 GDB now supports importing of namespaces in C++. This enables the
3653 user to inspect variables from imported namespaces. Support for
3654 namepace aliasing has also been added. So, if a namespace is
3655 aliased in the current scope (e.g. namepace C=A; ) the user can
3656 print variables using the alias (e.g. (gdb) print C::x).
3660 All known bugs relating to the printing of virtual base class were
3661 fixed. It is now possible to call overloaded static methods using a
3666 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3667 and reinterpret_cast<> are now handled by the C++ expression parser.
3671 Xilinx MicroBlaze microblaze-*-*
3676 Xilinx MicroBlaze microblaze
3679 * Multi-program debugging.
3681 GDB now has support for multi-program (a.k.a. multi-executable or
3682 multi-exec) debugging. This allows for debugging multiple inferiors
3683 simultaneously each running a different program under the same GDB
3684 session. See "Debugging Multiple Inferiors and Programs" in the
3685 manual for more information. This implied some user visible changes
3686 in the multi-inferior support. For example, "info inferiors" now
3687 lists inferiors that are not running yet or that have exited
3688 already. See also "New commands" and "New options" below.
3690 * New tracing features
3692 GDB's tracepoint facility now includes several new features:
3694 ** Trace state variables
3696 GDB tracepoints now include support for trace state variables, which
3697 are variables managed by the target agent during a tracing
3698 experiment. They are useful for tracepoints that trigger each
3699 other, so for instance one tracepoint can count hits in a variable,
3700 and then a second tracepoint has a condition that is true when the
3701 count reaches a particular value. Trace state variables share the
3702 $-syntax of GDB convenience variables, and can appear in both
3703 tracepoint actions and condition expressions. Use the "tvariable"
3704 command to create, and "info tvariables" to view; see "Trace State
3705 Variables" in the manual for more detail.
3709 GDB now includes an option for defining fast tracepoints, which
3710 targets may implement more efficiently, such as by installing a jump
3711 into the target agent rather than a trap instruction. The resulting
3712 speedup can be by two orders of magnitude or more, although the
3713 tradeoff is that some program locations on some target architectures
3714 might not allow fast tracepoint installation, for instance if the
3715 instruction to be replaced is shorter than the jump. To request a
3716 fast tracepoint, use the "ftrace" command, with syntax identical to
3717 the regular trace command.
3719 ** Disconnected tracing
3721 It is now possible to detach GDB from the target while it is running
3722 a trace experiment, then reconnect later to see how the experiment
3723 is going. In addition, a new variable disconnected-tracing lets you
3724 tell the target agent whether to continue running a trace if the
3725 connection is lost unexpectedly.
3729 GDB now has the ability to save the trace buffer into a file, and
3730 then use that file as a target, similarly to you can do with
3731 corefiles. You can select trace frames, print data that was
3732 collected in them, and use tstatus to display the state of the
3733 tracing run at the moment that it was saved. To create a trace
3734 file, use "tsave <filename>", and to use it, do "target tfile
3737 ** Circular trace buffer
3739 You can ask the target agent to handle the trace buffer as a
3740 circular buffer, discarding the oldest trace frames to make room for
3741 newer ones, by setting circular-trace-buffer to on. This feature may
3742 not be available for all target agents.
3747 The disassemble command, when invoked with two arguments, now requires
3748 the arguments to be comma-separated.
3751 The info variables command now displays variable definitions. Files
3752 which only declare a variable are not shown.
3755 The source command is now capable of sourcing Python scripts.
3756 This feature is dependent on the debugger being build with Python
3759 Related to this enhancement is also the introduction of a new command
3760 "set script-extension" (see below).
3762 * New commands (for set/show, see "New options" below)
3764 record save [<FILENAME>]
3765 Save a file (in core file format) containing the process record
3766 execution log for replay debugging at a later time.
3768 record restore <FILENAME>
3769 Restore the process record execution log that was saved at an
3770 earlier time, for replay debugging.
3772 add-inferior [-copies <N>] [-exec <FILENAME>]
3775 clone-inferior [-copies <N>] [ID]
3776 Make a new inferior ready to execute the same program another
3777 inferior has loaded.
3782 maint info program-spaces
3783 List the program spaces loaded into GDB.
3785 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3786 show remote interrupt-sequence
3787 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3788 as the sequence to the remote target in order to interrupt the execution.
3789 Ctrl-C is a default. Some system prefers BREAK which is high level of
3790 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3791 Magic SysRq g. It is BREAK signal and character 'g'.
3793 set remote interrupt-on-connect [on | off]
3794 show remote interrupt-on-connect
3795 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3796 remote target when gdb connects to it. This is needed when you debug
3799 set remotebreak [on | off]
3801 Deprecated. Use "set/show remote interrupt-sequence" instead.
3803 tvariable $NAME [ = EXP ]
3804 Create or modify a trace state variable.
3807 List trace state variables and their values.
3809 delete tvariable $NAME ...
3810 Delete one or more trace state variables.
3813 Evaluate the given expressions without collecting anything into the
3814 trace buffer. (Valid in tracepoint actions only.)
3816 ftrace FN / FILE:LINE / *ADDR
3817 Define a fast tracepoint at the given function, line, or address.
3819 * New expression syntax
3821 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3822 GDB now parses 0b101010 identically with 42.
3826 set follow-exec-mode new|same
3827 show follow-exec-mode
3828 Control whether GDB reuses the same inferior across an exec call or
3829 creates a new one. This is useful to be able to restart the old
3830 executable after the inferior having done an exec call.
3832 set default-collect EXPR, ...
3833 show default-collect
3834 Define a list of expressions to be collected at each tracepoint.
3835 This is a useful way to ensure essential items are not overlooked,
3836 such as registers or a critical global variable.
3838 set disconnected-tracing
3839 show disconnected-tracing
3840 If set to 1, the target is instructed to continue tracing if it
3841 loses its connection to GDB. If 0, the target is to stop tracing
3844 set circular-trace-buffer
3845 show circular-trace-buffer
3846 If set to on, the target is instructed to use a circular trace buffer
3847 and discard the oldest trace frames instead of stopping the trace due
3848 to a full trace buffer. If set to off, the trace stops when the buffer
3849 fills up. Some targets may not support this.
3851 set script-extension off|soft|strict
3852 show script-extension
3853 If set to "off", the debugger does not perform any script language
3854 recognition, and all sourced files are assumed to be GDB scripts.
3855 If set to "soft" (the default), files are sourced according to
3856 filename extension, falling back to GDB scripts if the first
3858 If set to "strict", files are sourced according to filename extension.
3860 set ada trust-PAD-over-XVS on|off
3861 show ada trust-PAD-over-XVS
3862 If off, activate a workaround against a bug in the debugging information
3863 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3864 the GCC sources for more information about the GNAT encoding and
3865 PAD types in particular). It is always safe to set this option to
3866 off, but this introduces a slight performance penalty. The default
3869 * Python API Improvements
3871 ** GDB provides the new class gdb.LazyString. This is useful in
3872 some pretty-printing cases. The new method gdb.Value.lazy_string
3873 provides a simple way to create objects of this type.
3875 ** The fields returned by gdb.Type.fields now have an
3876 `is_base_class' attribute.
3878 ** The new method gdb.Type.range returns the range of an array type.
3880 ** The new method gdb.parse_and_eval can be used to parse and
3881 evaluate an expression.
3883 * New remote packets
3886 Define a trace state variable.
3889 Get the current value of a trace state variable.
3892 Set desired tracing behavior upon disconnection.
3895 Set the trace buffer to be linear or circular.
3898 Get data about the tracepoints currently in use.
3902 Process record now works correctly with hardware watchpoints.
3904 Multiple bug fixes have been made to the mips-irix port, making it
3905 much more reliable. In particular:
3906 - Debugging threaded applications is now possible again. Previously,
3907 GDB would hang while starting the program, or while waiting for
3908 the program to stop at a breakpoint.
3909 - Attaching to a running process no longer hangs.
3910 - An error occurring while loading a core file has been fixed.
3911 - Changing the value of the PC register now works again. This fixes
3912 problems observed when using the "jump" command, or when calling
3913 a function from GDB, or even when assigning a new value to $pc.
3914 - With the "finish" and "return" commands, the return value for functions
3915 returning a small array is now correctly printed.
3916 - It is now possible to break on shared library code which gets executed
3917 during a shared library init phase (code executed while executing
3918 their .init section). Previously, the breakpoint would have no effect.
3919 - GDB is now able to backtrace through the signal handler for
3920 non-threaded programs.
3922 PIE (Position Independent Executable) programs debugging is now supported.
3923 This includes debugging execution of PIC (Position Independent Code) shared
3924 libraries although for that, it should be possible to run such libraries as an
3927 *** Changes in GDB 7.0
3929 * GDB now has an interface for JIT compilation. Applications that
3930 dynamically generate code can create symbol files in memory and register
3931 them with GDB. For users, the feature should work transparently, and
3932 for JIT developers, the interface is documented in the GDB manual in the
3933 "JIT Compilation Interface" chapter.
3935 * Tracepoints may now be conditional. The syntax is as for
3936 breakpoints; either an "if" clause appended to the "trace" command,
3937 or the "condition" command is available. GDB sends the condition to
3938 the target for evaluation using the same bytecode format as is used
3939 for tracepoint actions.
3941 * The disassemble command now supports: an optional /r modifier, print the
3942 raw instructions in hex as well as in symbolic form, and an optional /m
3943 modifier to print mixed source+assembly.
3945 * Process record and replay
3947 In a architecture environment that supports ``process record and
3948 replay'', ``process record and replay'' target can record a log of
3949 the process execution, and replay it with both forward and reverse
3952 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3953 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3954 set execution-direction {forward|reverse}, for targets that support
3957 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3958 feature is available with a native GDB running on kernel version
3961 * GDB now has support for multi-byte and wide character sets on the
3962 target. Strings whose character type is wchar_t, char16_t, or
3963 char32_t are now correctly printed. GDB supports wide- and unicode-
3964 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3965 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3966 `printf'. This feature requires iconv to work properly; if your
3967 system does not have a working iconv, GDB can use GNU libiconv. See
3968 the installation instructions for more information.
3970 * GDB now supports automatic retrieval of shared library files from
3971 remote targets. To use this feature, specify a system root that begins
3972 with the `remote:' prefix, either via the `set sysroot' command or via
3973 the `--with-sysroot' configure-time option.
3975 * "info sharedlibrary" now takes an optional regex of libraries to show,
3976 and it now reports if a shared library has no debugging information.
3978 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3979 now complete on file names.
3981 * When completing in expressions, gdb will attempt to limit
3982 completions to allowable structure or union fields, where appropriate.
3983 For instance, consider:
3985 # struct example { int f1; double f2; };
3986 # struct example variable;
3989 If the user types TAB at the end of this command line, the available
3990 completions will be "f1" and "f2".
3992 * Inlined functions are now supported. They show up in backtraces, and
3993 the "step", "next", and "finish" commands handle them automatically.
3995 * GDB now supports the token-splicing (##) and stringification (#)
3996 operators when expanding macros. It also supports variable-arity
3999 * GDB now supports inspecting extra signal information, exported by
4000 the new $_siginfo convenience variable. The feature is currently
4001 implemented on linux ARM, i386 and amd64.
4003 * GDB can now display the VFP floating point registers and NEON vector
4004 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4005 can provide these registers (requires Linux 2.6.30 or later). Remote
4006 and simulator targets may also provide them.
4008 * New remote packets
4011 Search memory for a sequence of bytes.
4014 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4015 operation over reliable transport links. Use of this packet is
4016 controlled by the `set remote noack-packet' command.
4019 Kill the process with the specified process ID. Use this in preference
4020 to `k' when multiprocess protocol extensions are supported.
4023 Obtains additional operating system information
4027 Read or write additional signal information.
4029 * Removed remote protocol undocumented extension
4031 An undocumented extension to the remote protocol's `S' stop reply
4032 packet that permited the stub to pass a process id was removed.
4033 Remote servers should use the `T' stop reply packet instead.
4035 * GDB now supports multiple function calling conventions according to the
4036 DWARF-2 DW_AT_calling_convention function attribute.
4038 * The SH target utilizes the aforementioned change to distinguish between gcc
4039 and Renesas calling convention. It also adds the new CLI commands
4040 `set/show sh calling-convention'.
4042 * GDB can now read compressed debug sections, as produced by GNU gold
4043 with the --compress-debug-sections=zlib flag.
4045 * 64-bit core files are now supported on AIX.
4047 * Thread switching is now supported on Tru64.
4049 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4050 which will be allocated using malloc later in program execution.
4052 * The qXfer:libraries:read remote procotol packet now allows passing a
4053 list of section offsets.
4055 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4056 conditions handling signals delivered during attach or thread creation
4057 have also been fixed.
4059 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4060 From the user's standpoint, all unqualified instances of True and False
4061 are treated as the standard definitions, regardless of context.
4063 * GDB now parses C++ symbol and type names more flexibly. For
4066 template<typename T> class C { };
4069 GDB will now correctly handle all of:
4071 ptype C<char const *>
4072 ptype C<char const*>
4073 ptype C<const char *>
4074 ptype C<const char*>
4076 * New features in the GDB remote stub, gdbserver
4078 - The "--wrapper" command-line argument tells gdbserver to use a
4079 wrapper program to launch programs for debugging.
4081 - On PowerPC and S/390 targets, it is now possible to use a single
4082 gdbserver executable to debug both 32-bit and 64-bit programs.
4083 (This requires gdbserver itself to be built as a 64-bit executable.)
4085 - gdbserver uses the new noack protocol mode for TCP connections to
4086 reduce communications latency, if also supported and enabled in GDB.
4088 - Support for the sparc64-linux-gnu target is now included in
4091 - The amd64-linux build of gdbserver now supports debugging both
4092 32-bit and 64-bit programs.
4094 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4095 now support hardware watchpoints, and will use them automatically
4100 GDB now has support for scripting using Python. Whether this is
4101 available is determined at configure time.
4103 New GDB commands can now be written in Python.
4105 * Ada tasking support
4107 Ada tasks can now be inspected in GDB. The following commands have
4111 Print the list of Ada tasks.
4113 Print detailed information about task number N.
4115 Print the task number of the current task.
4117 Switch the context of debugging to task number N.
4119 * Support for user-defined prefixed commands. The "define" command can
4120 add new commands to existing prefixes, e.g. "target".
4122 * Multi-inferior, multi-process debugging.
4124 GDB now has generalized support for multi-inferior debugging. See
4125 "Debugging Multiple Inferiors" in the manual for more information.
4126 Although availability still depends on target support, the command
4127 set is more uniform now. The GNU/Linux specific multi-forks support
4128 has been migrated to this new framework. This implied some user
4129 visible changes; see "New commands" and also "Removed commands"
4132 * Target descriptions can now describe the target OS ABI. See the
4133 "Target Description Format" section in the user manual for more
4136 * Target descriptions can now describe "compatible" architectures
4137 to indicate that the target can execute applications for a different
4138 architecture in addition to those for the main target architecture.
4139 See the "Target Description Format" section in the user manual for
4142 * Multi-architecture debugging.
4144 GDB now includes general supports for debugging applications on
4145 hybrid systems that use more than one single processor architecture
4146 at the same time. Each such hybrid architecture still requires
4147 specific support to be added. The only hybrid architecture supported
4148 in this version of GDB is the Cell Broadband Engine.
4150 * GDB now supports integrated debugging of Cell/B.E. applications that
4151 use both the PPU and SPU architectures. To enable support for hybrid
4152 Cell/B.E. debugging, you need to configure GDB to support both the
4153 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4154 --enable-targets configure option.
4156 * Non-stop mode debugging.
4158 For some targets, GDB now supports an optional mode of operation in
4159 which you can examine stopped threads while other threads continue
4160 to execute freely. This is referred to as non-stop mode, with the
4161 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4162 section in the user manual for more information.
4164 To be able to support remote non-stop debugging, a remote stub needs
4165 to implement the non-stop mode remote protocol extensions, as
4166 described in the "Remote Non-Stop" section of the user manual. The
4167 GDB remote stub, gdbserver, has been adjusted to support these
4168 extensions on linux targets.
4170 * New commands (for set/show, see "New options" below)
4172 catch syscall [NAME(S) | NUMBER(S)]
4173 Catch system calls. Arguments, which should be names of system
4174 calls or their numbers, mean catch only those syscalls. Without
4175 arguments, every syscall will be caught. When the inferior issues
4176 any of the specified syscalls, GDB will stop and announce the system
4177 call, both when it is called and when its call returns. This
4178 feature is currently available with a native GDB running on the
4179 Linux Kernel, under the following architectures: x86, x86_64,
4180 PowerPC and PowerPC64.
4182 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4184 Search memory for a sequence of bytes.
4186 maint set python print-stack
4187 maint show python print-stack
4188 Show a stack trace when an error is encountered in a Python script.
4191 Invoke CODE by passing it to the Python interpreter.
4196 These allow macros to be defined, undefined, and listed
4200 Show operating system information about processes.
4203 List the inferiors currently under GDB's control.
4206 Switch focus to inferior number NUM.
4209 Detach from inferior number NUM.
4212 Kill inferior number NUM.
4216 set spu stop-on-load
4217 show spu stop-on-load
4218 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4220 set spu auto-flush-cache
4221 show spu auto-flush-cache
4222 Control whether to automatically flush the software-managed cache
4223 during Cell/B.E. debugging.
4225 set sh calling-convention
4226 show sh calling-convention
4227 Control the calling convention used when calling SH target functions.
4230 show debug timestamp
4231 Control display of timestamps with GDB debugging output.
4233 set disassemble-next-line
4234 show disassemble-next-line
4235 Control display of disassembled source lines or instructions when
4238 set remote noack-packet
4239 show remote noack-packet
4240 Set/show the use of remote protocol QStartNoAckMode packet. See above
4241 under "New remote packets."
4243 set remote query-attached-packet
4244 show remote query-attached-packet
4245 Control use of remote protocol `qAttached' (query-attached) packet.
4247 set remote read-siginfo-object
4248 show remote read-siginfo-object
4249 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4252 set remote write-siginfo-object
4253 show remote write-siginfo-object
4254 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4257 set remote reverse-continue
4258 show remote reverse-continue
4259 Control use of remote protocol 'bc' (reverse-continue) packet.
4261 set remote reverse-step
4262 show remote reverse-step
4263 Control use of remote protocol 'bs' (reverse-step) packet.
4265 set displaced-stepping
4266 show displaced-stepping
4267 Control displaced stepping mode. Displaced stepping is a way to
4268 single-step over breakpoints without removing them from the debuggee.
4269 Also known as "out-of-line single-stepping".
4272 show debug displaced
4273 Control display of debugging info for displaced stepping.
4275 maint set internal-error
4276 maint show internal-error
4277 Control what GDB does when an internal error is detected.
4279 maint set internal-warning
4280 maint show internal-warning
4281 Control what GDB does when an internal warning is detected.
4286 Use a wrapper program to launch programs for debugging.
4288 set multiple-symbols (all|ask|cancel)
4289 show multiple-symbols
4290 The value of this variable can be changed to adjust the debugger behavior
4291 when an expression or a breakpoint location contains an ambiguous symbol
4292 name (an overloaded function name, for instance).
4294 set breakpoint always-inserted
4295 show breakpoint always-inserted
4296 Keep breakpoints always inserted in the target, as opposed to inserting
4297 them when resuming the target, and removing them when the target stops.
4298 This option can improve debugger performance on slow remote targets.
4300 set arm fallback-mode (arm|thumb|auto)
4301 show arm fallback-mode
4302 set arm force-mode (arm|thumb|auto)
4304 These commands control how ARM GDB determines whether instructions
4305 are ARM or Thumb. The default for both settings is auto, which uses
4306 the current CPSR value for instructions without symbols; previous
4307 versions of GDB behaved as if "set arm fallback-mode arm".
4309 set disable-randomization
4310 show disable-randomization
4311 Standalone programs run with the virtual address space randomization enabled
4312 by default on some platforms. This option keeps the addresses stable across
4313 multiple debugging sessions.
4317 Control whether other threads are stopped or not when some thread hits
4322 Requests that asynchronous execution is enabled in the target, if available.
4323 In this case, it's possible to resume target in the background, and interact
4324 with GDB while the target is running. "show target-async" displays the
4325 current state of asynchronous execution of the target.
4327 set target-wide-charset
4328 show target-wide-charset
4329 The target-wide-charset is the name of the character set that GDB
4330 uses when printing characters whose type is wchar_t.
4332 set tcp auto-retry (on|off)
4334 set tcp connect-timeout
4335 show tcp connect-timeout
4336 These commands allow GDB to retry failed TCP connections to a remote stub
4337 with a specified timeout period; this is useful if the stub is launched
4338 in parallel with GDB but may not be ready to accept connections immediately.
4340 set libthread-db-search-path
4341 show libthread-db-search-path
4342 Control list of directories which GDB will search for appropriate
4345 set schedule-multiple (on|off)
4346 show schedule-multiple
4347 Allow GDB to resume all threads of all processes or only threads of
4348 the current process.
4352 Use more aggressive caching for accesses to the stack. This improves
4353 performance of remote debugging (particularly backtraces) without
4354 affecting correctness.
4356 set interactive-mode (on|off|auto)
4357 show interactive-mode
4358 Control whether GDB runs in interactive mode (on) or not (off).
4359 When in interactive mode, GDB waits for the user to answer all
4360 queries. Otherwise, GDB does not wait and assumes the default
4361 answer. When set to auto (the default), GDB determines which
4362 mode to use based on the stdin settings.
4367 For program forks, this is replaced by the new more generic `info
4368 inferiors' command. To list checkpoints, you can still use the
4369 `info checkpoints' command, which was an alias for the `info forks'
4373 Replaced by the new `inferior' command. To switch between
4374 checkpoints, you can still use the `restart' command, which was an
4375 alias for the `fork' command.
4378 This is removed, since some targets don't have a notion of
4379 processes. To switch between processes, you can still use the
4380 `inferior' command using GDB's own inferior number.
4383 For program forks, this is replaced by the new more generic `kill
4384 inferior' command. To delete a checkpoint, you can still use the
4385 `delete checkpoint' command, which was an alias for the `delete
4389 For program forks, this is replaced by the new more generic `detach
4390 inferior' command. To detach a checkpoint, you can still use the
4391 `detach checkpoint' command, which was an alias for the `detach
4394 * New native configurations
4396 x86/x86_64 Darwin i[34567]86-*-darwin*
4398 x86_64 MinGW x86_64-*-mingw*
4402 Lattice Mico32 lm32-*
4403 x86 DICOS i[34567]86-*-dicos*
4404 x86_64 DICOS x86_64-*-dicos*
4407 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4408 (mingw32ce) debugging.
4414 These commands were actually not implemented on any target.
4416 *** Changes in GDB 6.8
4418 * New native configurations
4420 NetBSD/hppa hppa*-*netbsd*
4421 Xtensa GNU/Linux xtensa*-*-linux*
4425 NetBSD/hppa hppa*-*-netbsd*
4426 Xtensa GNU/Lunux xtensa*-*-linux*
4428 * Change in command line behavior -- corefiles vs. process ids.
4430 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4431 attaching to process NUMBER fails, GDB no longer attempts to open a
4432 core file named NUMBER. Attaching to a program using the -c option
4433 is no longer supported. Instead, use the '-p' or '--pid' options.
4435 * GDB can now be built as a native debugger for debugging Windows x86
4436 (mingw32) Portable Executable (PE) programs.
4438 * Pending breakpoints no longer change their number when their address
4441 * GDB now supports breakpoints with multiple locations,
4442 including breakpoints on C++ constructors, inside C++ templates,
4443 and in inlined functions.
4445 * GDB's ability to debug optimized code has been improved. GDB more
4446 accurately identifies function bodies and lexical blocks that occupy
4447 more than one contiguous range of addresses.
4449 * Target descriptions can now describe registers for PowerPC.
4451 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4452 registers on PowerPC targets.
4454 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4455 targets even when the libthread_db library is not available.
4457 * The GDB remote stub, gdbserver, now supports the new file transfer
4458 commands (remote put, remote get, and remote delete).
4460 * The GDB remote stub, gdbserver, now supports run and attach in
4461 extended-remote mode.
4463 * hppa*64*-*-hpux11* target broken
4464 The debugger is unable to start a program and fails with the following
4465 error: "Error trying to get information about dynamic linker".
4466 The gdb-6.7 release is also affected.
4468 * GDB now supports the --enable-targets= configure option to allow
4469 building a single GDB executable that supports multiple remote
4470 target architectures.
4472 * GDB now supports debugging C and C++ programs which use the
4473 Decimal Floating Point extension. In addition, the PowerPC target
4474 now has a set of pseudo-registers to inspect decimal float values
4475 stored in two consecutive float registers.
4477 * The -break-insert MI command can optionally create pending
4480 * Improved support for debugging Ada
4481 Many improvements to the Ada language support have been made. These
4483 - Better support for Ada2005 interface types
4484 - Improved handling of arrays and slices in general
4485 - Better support for Taft-amendment types
4486 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4488 - Improved command completion in Ada
4491 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4496 set print frame-arguments (all|scalars|none)
4497 show print frame-arguments
4498 The value of this variable can be changed to control which argument
4499 values should be printed by the debugger when displaying a frame.
4504 Transfer files to and from a remote target, and delete remote files.
4511 Transfer files to and from a remote target, and delete remote files.
4513 * New remote packets
4520 Open, close, read, write, and delete files on the remote system.
4523 Attach to an existing process on the remote system, in extended-remote
4527 Run a new process on the remote system, in extended-remote mode.
4529 *** Changes in GDB 6.7
4531 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4532 bfd, libiberty and opcodes, as revealed by static analysis donated by
4533 Coverity, Inc. (http://scan.coverity.com).
4535 * When looking up multiply-defined global symbols, GDB will now prefer the
4536 symbol definition in the current shared library if it was built using the
4537 -Bsymbolic linker option.
4539 * When the Text User Interface (TUI) is not configured, GDB will now
4540 recognize the -tui command-line option and print a message that the TUI
4543 * The GDB remote stub, gdbserver, now has lower overhead for high
4544 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4546 * GDB for MIPS targets now autodetects whether a remote target provides
4547 32-bit or 64-bit register values.
4549 * Support for C++ member pointers has been improved.
4551 * GDB now understands XML target descriptions, which specify the
4552 target's overall architecture. GDB can read a description from
4553 a local file or over the remote serial protocol.
4555 * Vectors of single-byte data use a new integer type which is not
4556 automatically displayed as character or string data.
4558 * The /s format now works with the print command. It displays
4559 arrays of single-byte integers and pointers to single-byte integers
4562 * Target descriptions can now describe target-specific registers,
4563 for architectures which have implemented the support (currently
4564 only ARM, M68K, and MIPS).
4566 * GDB and the GDB remote stub, gdbserver, now support the XScale
4569 * The GDB remote stub, gdbserver, has been updated to support
4570 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4571 has been rewritten to use the standard GDB remote protocol.
4573 * GDB can now step into C++ functions which are called through thunks.
4575 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4577 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4578 layout. It also supports a TextSeg= and DataSeg= response when only
4579 segment base addresses (rather than offsets) are available.
4581 * The /i format now outputs any trailing branch delay slot instructions
4582 immediately following the last instruction within the count specified.
4584 * The GDB remote protocol "T" stop reply packet now supports a
4585 "library" response. Combined with the new "qXfer:libraries:read"
4586 packet, this response allows GDB to debug shared libraries on targets
4587 where the operating system manages the list of loaded libraries (e.g.
4588 Windows and SymbianOS).
4590 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4591 (DLLs) on Windows and Windows CE targets.
4593 * GDB now supports a faster verification that a .debug file matches its binary
4594 according to its build-id signature, if the signature is present.
4600 Enable or disable hardware flow control (RTS/CTS) on the serial port
4601 when debugging using remote targets.
4603 set mem inaccessible-by-default
4604 show mem inaccessible-by-default
4605 If the target supplies a memory map, for instance via the remote
4606 protocol's "qXfer:memory-map:read" packet, setting this variable
4607 prevents GDB from accessing memory outside the memory map. This
4608 is useful for targets with memory mapped registers or which react
4609 badly to accesses of unmapped address space.
4611 set breakpoint auto-hw
4612 show breakpoint auto-hw
4613 If the target supplies a memory map, for instance via the remote
4614 protocol's "qXfer:memory-map:read" packet, setting this variable
4615 lets GDB use hardware breakpoints automatically for memory regions
4616 where it can not use software breakpoints. This covers both the
4617 "break" command and internal breakpoints used for other commands
4618 including "next" and "finish".
4621 catch exception unhandled
4622 Stop the program execution when Ada exceptions are raised.
4625 Stop the program execution when an Ada assertion failed.
4629 Set an alternate system root for target files. This is a more
4630 general version of "set solib-absolute-prefix", which is now
4631 an alias to "set sysroot".
4634 Provide extended SPU facility status information. This set of
4635 commands is available only when debugging the Cell/B.E. SPU
4638 * New native configurations
4640 OpenBSD/sh sh*-*openbsd*
4643 unset tdesc filename
4645 Use the specified local file as an XML target description, and do
4646 not query the target for its built-in description.
4650 OpenBSD/sh sh*-*-openbsd*
4651 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4652 Toshiba Media Processor mep-elf
4654 * New remote packets
4657 Ignore the specified signals; pass them directly to the debugged program
4658 without stopping other threads or reporting them to GDB.
4660 qXfer:features:read:
4661 Read an XML target description from the target, which describes its
4666 Read or write contents of an spufs file on the target system. These
4667 packets are available only on the Cell/B.E. SPU architecture.
4669 qXfer:libraries:read:
4670 Report the loaded shared libraries. Combined with new "T" packet
4671 response, this packet allows GDB to debug shared libraries on
4672 targets where the operating system manages the list of loaded
4673 libraries (e.g. Windows and SymbianOS).
4677 Support for these obsolete configurations has been removed.
4685 i[34567]86-*-lynxos*
4686 i[34567]86-*-netware*
4687 i[34567]86-*-sco3.2v5*
4688 i[34567]86-*-sco3.2v4*
4690 i[34567]86-*-sysv4.2*
4693 i[34567]86-*-unixware2*
4694 i[34567]86-*-unixware*
4703 * Other removed features
4710 Various m68k-only ROM monitors.
4717 Various Renesas ROM monitors and debugging interfaces for SH and
4722 Support for a Macraigor serial interface to on-chip debugging.
4723 GDB does not directly support the newer parallel or USB
4728 A debug information format. The predecessor to DWARF 2 and
4729 DWARF 3, which are still supported.
4731 Support for the HP aCC compiler on HP-UX/PA-RISC
4733 SOM-encapsulated symbolic debugging information, automatic
4734 invocation of pxdb, and the aCC custom C++ ABI. This does not
4735 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4736 with aCC can still be debugged on an assembly level.
4738 MIPS ".pdr" sections
4740 A MIPS-specific format used to describe stack frame layout
4741 in debugging information.
4745 GDB could work with an older version of Guile to debug
4746 the interpreter and Scheme programs running in it.
4748 set mips stack-arg-size
4749 set mips saved-gpreg-size
4751 Use "set mips abi" to control parameter passing for MIPS.
4753 *** Changes in GDB 6.6
4758 Cell Broadband Engine SPU spu-elf
4760 * GDB can now be configured as a cross-debugger targeting native Windows
4761 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4762 running on a Windows system over TCP/IP to debug Windows programs.
4764 * The GDB remote stub, gdbserver, has been updated to support Windows and
4765 Cygwin debugging. Both single-threaded and multi-threaded programs are
4768 * The "set trust-readonly-sections" command works again. This command was
4769 broken in GDB 6.3, 6.4, and 6.5.
4771 * The "load" command now supports writing to flash memory, if the remote
4772 stub provides the required support.
4774 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4775 longer requires symbolic debug information (e.g. DWARF-2).
4780 unset substitute-path
4781 show substitute-path
4782 Manage a list of substitution rules that GDB uses to rewrite the name
4783 of the directories where the sources are located. This can be useful
4784 for instance when the sources were moved to a different location
4785 between compilation and debugging.
4789 Print each CLI command as it is executed. Each command is prefixed with
4790 a number of `+' symbols representing the nesting depth.
4791 The source command now has a `-v' option to enable the same feature.
4795 The ARM Demon monitor support (RDP protocol, "target rdp").
4797 Kernel Object Display, an embedded debugging feature which only worked with
4798 an obsolete version of Cisco IOS.
4800 The 'set download-write-size' and 'show download-write-size' commands.
4802 * New remote packets
4805 Tell a stub about GDB client features, and request remote target features.
4806 The first feature implemented is PacketSize, which allows the target to
4807 specify the size of packets it can handle - to minimize the number of
4808 packets required and improve performance when connected to a remote
4812 Fetch an OS auxilliary vector from the remote stub. This packet is a
4813 more efficient replacement for qPart:auxv:read.
4815 qXfer:memory-map:read:
4816 Fetch a memory map from the remote stub, including information about
4817 RAM, ROM, and flash memory devices.
4822 Erase and program a flash memory device.
4824 * Removed remote packets
4827 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4828 used it, and only gdbserver implemented it.
4830 *** Changes in GDB 6.5
4834 Renesas M32C/M16C m32c-elf
4836 Morpho Technologies ms1 ms1-elf
4840 init-if-undefined Initialize a convenience variable, but
4841 only if it doesn't already have a value.
4843 The following commands are presently only implemented for native GNU/Linux:
4845 checkpoint Save a snapshot of the program state.
4847 restart <n> Return the program state to a
4848 previously saved state.
4850 info checkpoints List currently saved checkpoints.
4852 delete-checkpoint <n> Delete a previously saved checkpoint.
4854 set|show detach-on-fork Tell gdb whether to detach from a newly
4855 forked process, or to keep debugging it.
4857 info forks List forks of the user program that
4858 are available to be debugged.
4860 fork <n> Switch to debugging one of several
4861 forks of the user program that are
4862 available to be debugged.
4864 delete-fork <n> Delete a fork from the list of forks
4865 that are available to be debugged (and
4866 kill the forked process).
4868 detach-fork <n> Delete a fork from the list of forks
4869 that are available to be debugged (and
4870 allow the process to continue).
4874 Morpho Technologies ms2 ms1-elf
4876 * Improved Windows host support
4878 GDB now builds as a cross debugger hosted on i686-mingw32, including
4879 native console support, and remote communications using either
4880 network sockets or serial ports.
4882 * Improved Modula-2 language support
4884 GDB can now print most types in the Modula-2 syntax. This includes:
4885 basic types, set types, record types, enumerated types, range types,
4886 pointer types and ARRAY types. Procedure var parameters are correctly
4887 printed and hexadecimal addresses and character constants are also
4888 written in the Modula-2 syntax. Best results can be obtained by using
4889 GNU Modula-2 together with the -gdwarf-2 command line option.
4893 The ARM rdi-share module.
4895 The Netware NLM debug server.
4897 *** Changes in GDB 6.4
4899 * New native configurations
4901 OpenBSD/arm arm*-*-openbsd*
4902 OpenBSD/mips64 mips64-*-openbsd*
4906 Morpho Technologies ms1 ms1-elf
4908 * New command line options
4910 --batch-silent As for --batch, but totally silent.
4911 --return-child-result The debugger will exist with the same value
4912 the child (debugged) program exited with.
4913 --eval-command COMMAND, -ex COMMAND
4914 Execute a single GDB CLI command. This may be
4915 specified multiple times and in conjunction
4916 with the --command (-x) option.
4918 * Deprecated commands removed
4920 The following commands, that were deprecated in 2000, have been
4924 set|show arm disassembly-flavor set|show arm disassembler
4925 othernames set arm disassembler
4926 set|show remotedebug set|show debug remote
4927 set|show archdebug set|show debug arch
4928 set|show eventdebug set|show debug event
4931 * New BSD user-level threads support
4933 It is now possible to debug programs using the user-level threads
4934 library on OpenBSD and FreeBSD. Currently supported (target)
4937 FreeBSD/amd64 x86_64-*-freebsd*
4938 FreeBSD/i386 i386-*-freebsd*
4939 OpenBSD/i386 i386-*-openbsd*
4941 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4942 are not yet supported.
4944 * New support for Matsushita MN10300 w/sim added
4945 (Work in progress). mn10300-elf.
4947 * REMOVED configurations and files
4949 VxWorks and the XDR protocol *-*-vxworks
4950 Motorola MCORE mcore-*-*
4951 National Semiconductor NS32000 ns32k-*-*
4953 * New "set print array-indexes" command
4955 After turning this setting "on", GDB prints the index of each element
4956 when displaying arrays. The default is "off" to preserve the previous
4959 * VAX floating point support
4961 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4963 * User-defined command support
4965 In addition to using $arg0..$arg9 for argument passing, it is now possible
4966 to use $argc to determine now many arguments have been passed. See the
4967 section on user-defined commands in the user manual for more information.
4969 *** Changes in GDB 6.3:
4971 * New command line option
4973 GDB now accepts -l followed by a number to set the timeout for remote
4976 * GDB works with GCC -feliminate-dwarf2-dups
4978 GDB now supports a more compact representation of DWARF-2 debug
4979 information using DW_FORM_ref_addr references. These are produced
4980 by GCC with the option -feliminate-dwarf2-dups and also by some
4981 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4982 to use -feliminate-dwarf2-dups.
4984 * Internationalization
4986 When supported by the host system, GDB will be built with
4987 internationalization (libintl). The task of marking up the sources is
4988 continued, we're looking forward to our first translation.
4992 Initial support for debugging programs compiled with the GNAT
4993 implementation of the Ada programming language has been integrated
4994 into GDB. In this release, support is limited to expression evaluation.
4996 * New native configurations
4998 GNU/Linux/m32r m32r-*-linux-gnu
5002 GDB's remote protocol now includes support for the 'p' packet. This
5003 packet is used to fetch individual registers from a remote inferior.
5005 * END-OF-LIFE registers[] compatibility module
5007 GDB's internal register infrastructure has been completely rewritten.
5008 The new infrastructure making possible the implementation of key new
5009 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5012 GDB 6.3 will be the last release to include the the registers[]
5013 compatibility module that allowed out-of-date configurations to
5014 continue to work. This change directly impacts the following
5024 powerpc bdm protocol
5026 Unless there is activity to revive these configurations, they will be
5027 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5029 * OBSOLETE configurations and files
5031 Configurations that have been declared obsolete in this release have
5032 been commented out. Unless there is activity to revive these
5033 configurations, the next release of GDB will have their sources
5034 permanently REMOVED.
5043 *** Changes in GDB 6.2.1:
5045 * MIPS `break main; run' gave an heuristic-fence-post warning
5047 When attempting to run even a simple program, a warning about
5048 heuristic-fence-post being hit would be reported. This problem has
5051 * MIPS IRIX 'long double' crashed GDB
5053 When examining a long double variable, GDB would get a segmentation
5054 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5055 IRIX long double values).
5059 A bug in the VAX stack code was causing problems with the "next"
5060 command. This problem has been fixed.
5062 *** Changes in GDB 6.2:
5064 * Fix for ``many threads''
5066 On GNU/Linux systems that use the NPTL threads library, a program
5067 rapidly creating and deleting threads would confuse GDB leading to the
5070 ptrace: No such process.
5071 thread_db_get_info: cannot get thread info: generic error
5073 This problem has been fixed.
5075 * "-async" and "-noasync" options removed.
5077 Support for the broken "-noasync" option has been removed (it caused
5080 * New ``start'' command.
5082 This command runs the program until the begining of the main procedure.
5084 * New BSD Kernel Data Access Library (libkvm) interface
5086 Using ``target kvm'' it is now possible to debug kernel core dumps and
5087 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5088 platforms. Currently supported (native-only) configurations are:
5090 FreeBSD/amd64 x86_64-*-freebsd*
5091 FreeBSD/i386 i?86-*-freebsd*
5092 NetBSD/i386 i?86-*-netbsd*
5093 NetBSD/m68k m68*-*-netbsd*
5094 NetBSD/sparc sparc-*-netbsd*
5095 OpenBSD/amd64 x86_64-*-openbsd*
5096 OpenBSD/i386 i?86-*-openbsd*
5097 OpenBSD/m68k m68*-openbsd*
5098 OpenBSD/sparc sparc-*-openbsd*
5100 * Signal trampoline code overhauled
5102 Many generic problems with GDB's signal handling code have been fixed.
5103 These include: backtraces through non-contiguous stacks; recognition
5104 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5105 call; backtrace through a signal trampoline; step into and out of
5106 signal handlers; and single-stepping in the signal trampoline.
5108 Please note that kernel bugs are a limiting factor here. These
5109 features have been shown to work on an s390 GNU/Linux system that
5110 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5112 * Cygwin support for DWARF 2 added.
5114 * New native configurations
5116 GNU/Linux/hppa hppa*-*-linux*
5117 OpenBSD/hppa hppa*-*-openbsd*
5118 OpenBSD/m68k m68*-*-openbsd*
5119 OpenBSD/m88k m88*-*-openbsd*
5120 OpenBSD/powerpc powerpc-*-openbsd*
5121 NetBSD/vax vax-*-netbsd*
5122 OpenBSD/vax vax-*-openbsd*
5124 * END-OF-LIFE frame compatibility module
5126 GDB's internal frame infrastructure has been completely rewritten.
5127 The new infrastructure making it possible to support key new features
5128 including DWARF 2 Call Frame Information. To aid in the task of
5129 migrating old configurations to this new infrastructure, a
5130 compatibility module, that allowed old configurations to continue to
5131 work, was also included.
5133 GDB 6.2 will be the last release to include this frame compatibility
5134 module. This change directly impacts the following configurations:
5144 Unless there is activity to revive these configurations, they will be
5145 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5147 * REMOVED configurations and files
5149 Sun 3, running SunOS 3 m68*-*-sunos3*
5150 Sun 3, running SunOS 4 m68*-*-sunos4*
5151 Sun 2, running SunOS 3 m68000-*-sunos3*
5152 Sun 2, running SunOS 4 m68000-*-sunos4*
5153 Motorola 680x0 running LynxOS m68*-*-lynxos*
5154 AT&T 3b1/Unix pc m68*-att-*
5155 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5156 decstation mips-dec-* mips-little-*
5157 riscos mips-*-riscos* mips-*-sysv*
5158 sonymips mips-sony-*
5159 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5161 *** Changes in GDB 6.1.1:
5163 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5165 The TUI (Text-mode User Interface) is now built as part of a default
5166 GDB configuration. It is enabled by either selecting the TUI with the
5167 command line option "-i=tui" or by running the separate "gdbtui"
5168 program. For more information on the TUI, see the manual "Debugging
5171 * Pending breakpoint support (also included in GDB 6.1)
5173 Support has been added to allow you to specify breakpoints in shared
5174 libraries that have not yet been loaded. If a breakpoint location
5175 cannot be found, and the "breakpoint pending" option is set to auto,
5176 GDB queries you if you wish to make the breakpoint pending on a future
5177 shared-library load. If and when GDB resolves the breakpoint symbol,
5178 the pending breakpoint is removed as one or more regular breakpoints
5181 Pending breakpoints are very useful for GCJ Java debugging.
5183 * Fixed ISO-C build problems
5185 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5186 non ISO-C code that stopped them being built using a more strict ISO-C
5187 compiler (e.g., IBM's C compiler).
5189 * Fixed build problem on IRIX 5
5191 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5192 wasn't able to compile compile on an IRIX 5 system.
5194 * Added execute permission to gdb/gdbserver/configure
5196 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5197 permission. This bug would cause configure to fail on a number of
5198 systems (Solaris, IRIX). Ref: server/519.
5200 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5202 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5203 has been updated to use constant array sizes.
5205 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5207 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5208 its generated DWARF Call Frame Info. This encoding was causing GDB to
5209 panic, that panic has been fixed. Ref: gdb/1628.
5211 * Fixed a problem when examining parameters in shared library code.
5213 When examining parameters in optimized shared library code generated
5214 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5215 not available''. GDB now correctly displays the variable's value.
5217 *** Changes in GDB 6.1:
5219 * Removed --with-mmalloc
5221 Support for the mmalloc memory manager has been removed, as it
5222 conflicted with the internal gdb byte cache.
5224 * Changes in AMD64 configurations
5226 The AMD64 target now includes the %cs and %ss registers. As a result
5227 the AMD64 remote protocol has changed; this affects the floating-point
5228 and SSE registers. If you rely on those registers for your debugging,
5229 you should upgrade gdbserver on the remote side.
5231 * Revised SPARC target
5233 The SPARC target has been completely revised, incorporating the
5234 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5235 support for LynxOS and SunOS 4 has been dropped. Calling functions
5236 from within GDB on operating systems with a non-executable stack
5237 (Solaris, OpenBSD) now works.
5241 GDB has a new C++ demangler which does a better job on the mangled
5242 names generated by current versions of g++. It also runs faster, so
5243 with this and other changes gdb should now start faster on large C++
5246 * DWARF 2 Location Expressions
5248 GDB support for location expressions has been extended to support function
5249 arguments and frame bases. Older versions of GDB could crash when they
5252 * C++ nested types and namespaces
5254 GDB's support for nested types and namespaces in C++ has been
5255 improved, especially if you use the DWARF 2 debugging format. (This
5256 is the default for recent versions of GCC on most platforms.)
5257 Specifically, if you have a class "Inner" defined within a class or
5258 namespace "Outer", then GDB realizes that the class's name is
5259 "Outer::Inner", not simply "Inner". This should greatly reduce the
5260 frequency of complaints about not finding RTTI symbols. In addition,
5261 if you are stopped at inside of a function defined within a namespace,
5262 GDB modifies its name lookup accordingly.
5264 * New native configurations
5266 NetBSD/amd64 x86_64-*-netbsd*
5267 OpenBSD/amd64 x86_64-*-openbsd*
5268 OpenBSD/alpha alpha*-*-openbsd*
5269 OpenBSD/sparc sparc-*-openbsd*
5270 OpenBSD/sparc64 sparc64-*-openbsd*
5272 * New debugging protocols
5274 M32R with SDI protocol m32r-*-elf*
5276 * "set prompt-escape-char" command deleted.
5278 The command "set prompt-escape-char" has been deleted. This command,
5279 and its very obscure effet on GDB's prompt, was never documented,
5280 tested, nor mentioned in the NEWS file.
5282 * OBSOLETE configurations and files
5284 Configurations that have been declared obsolete in this release have
5285 been commented out. Unless there is activity to revive these
5286 configurations, the next release of GDB will have their sources
5287 permanently REMOVED.
5289 Sun 3, running SunOS 3 m68*-*-sunos3*
5290 Sun 3, running SunOS 4 m68*-*-sunos4*
5291 Sun 2, running SunOS 3 m68000-*-sunos3*
5292 Sun 2, running SunOS 4 m68000-*-sunos4*
5293 Motorola 680x0 running LynxOS m68*-*-lynxos*
5294 AT&T 3b1/Unix pc m68*-att-*
5295 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5296 decstation mips-dec-* mips-little-*
5297 riscos mips-*-riscos* mips-*-sysv*
5298 sonymips mips-sony-*
5299 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5301 * REMOVED configurations and files
5303 SGI Irix-4.x mips-sgi-irix4 or iris4
5304 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5305 Z8000 simulator z8k-zilog-none or z8ksim
5306 Matsushita MN10200 w/simulator mn10200-*-*
5307 H8/500 simulator h8500-hitachi-hms or h8500hms
5308 HP/PA running BSD hppa*-*-bsd*
5309 HP/PA running OSF/1 hppa*-*-osf*
5310 HP/PA Pro target hppa*-*-pro*
5311 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5312 386BSD i[3456]86-*-bsd*
5313 Sequent family i[3456]86-sequent-sysv4*
5314 i[3456]86-sequent-sysv*
5315 i[3456]86-sequent-bsd*
5316 SPARC running LynxOS sparc-*-lynxos*
5317 SPARC running SunOS 4 sparc-*-sunos4*
5318 Tsqware Sparclet sparclet-*-*
5319 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5321 *** Changes in GDB 6.0:
5325 Support for debugging the Objective-C programming language has been
5326 integrated into GDB.
5328 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5330 DWARF 2's Call Frame Information makes available compiler generated
5331 information that more exactly describes the program's run-time stack.
5332 By using this information, GDB is able to provide more robust stack
5335 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5336 have been updated to use a new backtrace mechanism which includes
5337 DWARF 2 CFI support.
5341 GDB's remote protocol has been extended to include support for hosted
5342 file I/O (where the remote target uses GDB's file system). See GDB's
5343 remote protocol documentation for details.
5345 * All targets using the new architecture framework.
5347 All of GDB's targets have been updated to use the new internal
5348 architecture framework. The way is now open for future GDB releases
5349 to include cross-architecture native debugging support (i386 on amd64,
5352 * GNU/Linux's Thread Local Storage (TLS)
5354 GDB now includes support for for the GNU/Linux implementation of
5355 per-thread variables.
5357 * GNU/Linux's Native POSIX Thread Library (NPTL)
5359 GDB's thread code has been updated to work with either the new
5360 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5362 * Separate debug info.
5364 GDB, in conjunction with BINUTILS, now supports a mechanism for
5365 automatically loading debug information from a separate file. Instead
5366 of shipping full debug and non-debug versions of system libraries,
5367 system integrators can now instead ship just the stripped libraries
5368 and optional debug files.
5370 * DWARF 2 Location Expressions
5372 DWARF 2 Location Expressions allow the compiler to more completely
5373 describe the location of variables (even in optimized code) to the
5376 GDB now includes preliminary support for location expressions (support
5377 for DW_OP_piece is still missing).
5381 A number of long standing bugs that caused GDB to die while starting a
5382 Java application have been fixed. GDB's Java support is now
5383 considered "useable".
5385 * GNU/Linux support for fork, vfork, and exec.
5387 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5388 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5391 * GDB supports logging output to a file
5393 There are two new commands, "set logging" and "show logging", which can be
5394 used to capture GDB's output to a file.
5396 * The meaning of "detach" has changed for gdbserver
5398 The "detach" command will now resume the application, as documented. To
5399 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5402 * d10v, m68hc11 `regs' command deprecated
5404 The `info registers' command has been updated so that it displays the
5405 registers using a format identical to the old `regs' command.
5409 A new command, "maint set profile on/off", has been added. This command can
5410 be used to enable or disable profiling while running GDB, to profile a
5411 session or a set of commands. In addition there is a new configure switch,
5412 "--enable-profiling", which will cause GDB to be compiled with profiling
5413 data, for more informative profiling results.
5415 * Default MI syntax changed to "mi2".
5417 The default MI (machine interface) syntax, enabled by the command line
5418 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5419 "mi1", can be enabled by specifying the option "-i=mi1".
5421 Support for the original "mi0" syntax (included in GDB 5.0) has been
5424 Fix for gdb/192: removed extraneous space when displaying frame level.
5425 Fix for gdb/672: update changelist is now output in mi list format.
5426 Fix for gdb/702: a -var-assign that updates the value now shows up
5427 in a subsequent -var-update.
5429 * New native configurations.
5431 FreeBSD/amd64 x86_64-*-freebsd*
5433 * Multi-arched targets.
5435 HP/PA HPUX11 hppa*-*-hpux*
5436 Renesas M32R/D w/simulator m32r-*-elf*
5438 * OBSOLETE configurations and files
5440 Configurations that have been declared obsolete in this release have
5441 been commented out. Unless there is activity to revive these
5442 configurations, the next release of GDB will have their sources
5443 permanently REMOVED.
5445 Z8000 simulator z8k-zilog-none or z8ksim
5446 Matsushita MN10200 w/simulator mn10200-*-*
5447 H8/500 simulator h8500-hitachi-hms or h8500hms
5448 HP/PA running BSD hppa*-*-bsd*
5449 HP/PA running OSF/1 hppa*-*-osf*
5450 HP/PA Pro target hppa*-*-pro*
5451 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5452 Sequent family i[3456]86-sequent-sysv4*
5453 i[3456]86-sequent-sysv*
5454 i[3456]86-sequent-bsd*
5455 Tsqware Sparclet sparclet-*-*
5456 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5458 * REMOVED configurations and files
5461 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5462 IBM AIX PS/2 i[3456]86-*-aix
5463 i386 running Mach 3.0 i[3456]86-*-mach3*
5464 i386 running Mach i[3456]86-*-mach*
5465 i386 running OSF/1 i[3456]86-*osf1mk*
5466 HP/Apollo 68k Family m68*-apollo*-sysv*,
5468 m68*-hp-bsd*, m68*-hp-hpux*
5469 Argonaut Risc Chip (ARC) arc-*-*
5470 Mitsubishi D30V d30v-*-*
5471 Fujitsu FR30 fr30-*-elf*
5472 OS/9000 i[34]86-*-os9k
5473 I960 with MON960 i960-*-coff
5475 * MIPS $fp behavior changed
5477 The convenience variable $fp, for the MIPS, now consistently returns
5478 the address of the current frame's base. Previously, depending on the
5479 context, $fp could refer to either $sp or the current frame's base
5480 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5481 The GNU Source-Level Debugger''.
5483 *** Changes in GDB 5.3:
5485 * GNU/Linux shared library multi-threaded performance improved.
5487 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5488 `/proc', in preference to `ptrace' for memory reads. This may result
5489 in an improvement in the start-up time of multi-threaded, shared
5490 library applications when run under GDB. One GDB user writes: ``loads
5491 shared libs like mad''.
5493 * ``gdbserver'' now supports multi-threaded applications on some targets
5495 Support for debugging multi-threaded applications which use
5496 the GNU/Linux LinuxThreads package has been added for
5497 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5498 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5500 * GDB now supports C/C++ preprocessor macros.
5502 GDB now expands preprocessor macro invocations in C/C++ expressions,
5503 and provides various commands for showing macro definitions and how
5506 The new command `macro expand EXPRESSION' expands any macro
5507 invocations in expression, and shows the result.
5509 The new command `show macro MACRO-NAME' shows the definition of the
5510 macro named MACRO-NAME, and where it was defined.
5512 Most compilers don't include information about macros in the debugging
5513 information by default. In GCC 3.1, for example, you need to compile
5514 your program with the options `-gdwarf-2 -g3'. If the macro
5515 information is present in the executable, GDB will read it.
5517 * Multi-arched targets.
5519 DEC Alpha (partial) alpha*-*-*
5520 DEC VAX (partial) vax-*-*
5522 National Semiconductor NS32000 (partial) ns32k-*-*
5523 Motorola 68000 (partial) m68k-*-*
5524 Motorola MCORE mcore-*-*
5528 Fujitsu FRV architecture added by Red Hat frv*-*-*
5531 * New native configurations
5533 Alpha NetBSD alpha*-*-netbsd*
5534 SH NetBSD sh*-*-netbsdelf*
5535 MIPS NetBSD mips*-*-netbsd*
5536 UltraSPARC NetBSD sparc64-*-netbsd*
5538 * OBSOLETE configurations and files
5540 Configurations that have been declared obsolete in this release have
5541 been commented out. Unless there is activity to revive these
5542 configurations, the next release of GDB will have their sources
5543 permanently REMOVED.
5545 Mitsubishi D30V d30v-*-*
5546 OS/9000 i[34]86-*-os9k
5547 IBM AIX PS/2 i[3456]86-*-aix
5548 Fujitsu FR30 fr30-*-elf*
5549 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5550 Argonaut Risc Chip (ARC) arc-*-*
5551 i386 running Mach 3.0 i[3456]86-*-mach3*
5552 i386 running Mach i[3456]86-*-mach*
5553 i386 running OSF/1 i[3456]86-*osf1mk*
5554 HP/Apollo 68k Family m68*-apollo*-sysv*,
5556 m68*-hp-bsd*, m68*-hp-hpux*
5557 I960 with MON960 i960-*-coff
5559 * OBSOLETE languages
5561 CHILL, a Pascal like language used by telecommunications companies.
5563 * REMOVED configurations and files
5565 AMD 29k family via UDI a29k-amd-udi, udi29k
5566 A29K VxWorks a29k-*-vxworks
5567 AMD 29000 embedded, using EBMON a29k-none-none
5568 AMD 29000 embedded with COFF a29k-none-coff
5569 AMD 29000 embedded with a.out a29k-none-aout
5571 testsuite/gdb.hp/gdb.threads-hp/ directory
5573 * New command "set max-user-call-depth <nnn>"
5575 This command allows the user to limit the call depth of user-defined
5576 commands. The default is 1024.
5578 * Changes in FreeBSD/i386 native debugging.
5580 Support for the "generate-core-file" has been added.
5582 * New commands "dump", "append", and "restore".
5584 These commands allow data to be copied from target memory
5585 to a bfd-format or binary file (dump and append), and back
5586 from a file into memory (restore).
5588 * Improved "next/step" support on multi-processor Alpha Tru64.
5590 The previous single-step mechanism could cause unpredictable problems,
5591 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5592 of a software single-step mechanism prevents this.
5594 *** Changes in GDB 5.2.1:
5602 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5603 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5604 Fix, by Joel Brobecker imported from mainline.
5606 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5607 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5608 Fix, by Fred Fish, imported from mainline.
5610 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5611 Surprisingly enough, it works now.
5612 By Michal Ludvig, imported from mainline.
5614 i386 hardware watchpoint support:
5615 avoid misses on second run for some targets.
5616 By Pierre Muller, imported from mainline.
5618 *** Changes in GDB 5.2:
5620 * New command "set trust-readonly-sections on[off]".
5622 This command is a hint that tells gdb that read-only sections
5623 really are read-only (ie. that their contents will not change).
5624 In this mode, gdb will go to the object file rather than the
5625 target to read memory from read-only sections (such as ".text").
5626 This can be a significant performance improvement on some
5627 (notably embedded) targets.
5629 * New command "generate-core-file" (or "gcore").
5631 This new gdb command allows the user to drop a core file of the child
5632 process state at any time. So far it's been implemented only for
5633 GNU/Linux and Solaris, but should be relatively easily ported to other
5634 hosts. Argument is core file name (defaults to core.<pid>).
5636 * New command line option
5638 GDB now accepts --pid or -p followed by a process id.
5640 * Change in command line behavior -- corefiles vs. process ids.
5642 There is a subtle behavior in the way in which GDB handles
5643 command line arguments. The first non-flag argument is always
5644 a program to debug, but the second non-flag argument may either
5645 be a corefile or a process id. Previously, GDB would attempt to
5646 open the second argument as a corefile, and if that failed, would
5647 issue a superfluous error message and then attempt to attach it as
5648 a process. Now, if the second argument begins with a non-digit,
5649 it will be treated as a corefile. If it begins with a digit,
5650 GDB will attempt to attach it as a process, and if no such process
5651 is found, will then attempt to open it as a corefile.
5653 * Changes in ARM configurations.
5655 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5656 configuration is fully multi-arch.
5658 * New native configurations
5660 ARM NetBSD arm*-*-netbsd*
5661 x86 OpenBSD i[3456]86-*-openbsd*
5662 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5663 Sparc64 running FreeBSD sparc64-*-freebsd*
5667 Sanyo XStormy16 xstormy16-elf
5669 * OBSOLETE configurations and files
5671 Configurations that have been declared obsolete in this release have
5672 been commented out. Unless there is activity to revive these
5673 configurations, the next release of GDB will have their sources
5674 permanently REMOVED.
5676 AMD 29k family via UDI a29k-amd-udi, udi29k
5677 A29K VxWorks a29k-*-vxworks
5678 AMD 29000 embedded, using EBMON a29k-none-none
5679 AMD 29000 embedded with COFF a29k-none-coff
5680 AMD 29000 embedded with a.out a29k-none-aout
5682 testsuite/gdb.hp/gdb.threads-hp/ directory
5684 * REMOVED configurations and files
5686 TI TMS320C80 tic80-*-*
5688 PowerPC Solaris powerpcle-*-solaris*
5689 PowerPC Windows NT powerpcle-*-cygwin32
5690 PowerPC Netware powerpc-*-netware*
5691 Harris/CXUX m88k m88*-harris-cxux*
5692 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5693 ns32k-utek-sysv* ns32k-utek-*
5694 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5695 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5696 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5697 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5698 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5700 * Changes to command line processing
5702 The new `--args' feature can be used to specify command-line arguments
5703 for the inferior from gdb's command line.
5705 * Changes to key bindings
5707 There is a new `operate-and-get-next' function bound to `C-o'.
5709 *** Changes in GDB 5.1.1
5711 Fix compile problem on DJGPP.
5713 Fix a problem with floating-point registers on the i386 being
5716 Fix to stop GDB crashing on .debug_str debug info.
5718 Numerous documentation fixes.
5720 Numerous testsuite fixes.
5722 *** Changes in GDB 5.1:
5724 * New native configurations
5726 Alpha FreeBSD alpha*-*-freebsd*
5727 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5728 MIPS GNU/Linux mips*-*-linux*
5729 MIPS SGI Irix 6.x mips*-sgi-irix6*
5730 ia64 AIX ia64-*-aix*
5731 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5735 Motorola 68HC11 and 68HC12 m68hc11-elf
5737 UltraSparc running GNU/Linux sparc64-*-linux*
5739 * OBSOLETE configurations and files
5741 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5742 Harris/CXUX m88k m88*-harris-cxux*
5743 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5744 ns32k-utek-sysv* ns32k-utek-*
5745 TI TMS320C80 tic80-*-*
5747 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5748 PowerPC Solaris powerpcle-*-solaris*
5749 PowerPC Windows NT powerpcle-*-cygwin32
5750 PowerPC Netware powerpc-*-netware*
5751 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5752 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5753 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5754 Apple Macintosh (MPW) host N/A
5756 stuff.c (Program to stuff files into a specially prepared space in kdb)
5757 kdb-start.c (Main loop for the standalone kernel debugger)
5759 Configurations that have been declared obsolete in this release have
5760 been commented out. Unless there is activity to revive these
5761 configurations, the next release of GDB will have their sources
5762 permanently REMOVED.
5764 * REMOVED configurations and files
5766 Altos 3068 m68*-altos-*
5767 Convex c1-*-*, c2-*-*
5769 ARM RISCix arm-*-* (as host)
5773 * GDB has been converted to ISO C.
5775 GDB's source code has been converted to ISO C. In particular, the
5776 sources are fully protoized, and rely on standard headers being
5781 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5783 * The MI enabled by default.
5785 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5786 revised and enabled by default. Packages which use GDB as a debugging
5787 engine behind a UI or another front end are encouraged to switch to
5788 using the GDB/MI interface, instead of the old annotations interface
5789 which is now deprecated.
5791 * Support for debugging Pascal programs.
5793 GDB now includes support for debugging Pascal programs. The following
5794 main features are supported:
5796 - Pascal-specific data types such as sets;
5798 - automatic recognition of Pascal sources based on file-name
5801 - Pascal-style display of data types, variables, and functions;
5803 - a Pascal expression parser.
5805 However, some important features are not yet supported.
5807 - Pascal string operations are not supported at all;
5809 - there are some problems with boolean types;
5811 - Pascal type hexadecimal constants are not supported
5812 because they conflict with the internal variables format;
5814 - support for Pascal objects and classes is not full yet;
5816 - unlike Pascal, GDB is case-sensitive for symbol names.
5818 * Changes in completion.
5820 Commands such as `shell', `run' and `set args', which pass arguments
5821 to inferior programs, now complete on file names, similar to what
5822 users expect at the shell prompt.
5824 Commands which accept locations, such as `disassemble', `print',
5825 `breakpoint', `until', etc. now complete on filenames as well as
5826 program symbols. Thus, if you type "break foob TAB", and the source
5827 files linked into the programs include `foobar.c', that file name will
5828 be one of the candidates for completion. However, file names are not
5829 considered for completion after you typed a colon that delimits a file
5830 name from a name of a function in that file, as in "break foo.c:bar".
5832 `set demangle-style' completes on available demangling styles.
5834 * New platform-independent commands:
5836 It is now possible to define a post-hook for a command as well as a
5837 hook that runs before the command. For more details, see the
5838 documentation of `hookpost' in the GDB manual.
5840 * Changes in GNU/Linux native debugging.
5842 Support for debugging multi-threaded programs has been completely
5843 revised for all platforms except m68k and sparc. You can now debug as
5844 many threads as your system allows you to have.
5846 Attach/detach is supported for multi-threaded programs.
5848 Support for SSE registers was added for x86. This doesn't work for
5849 multi-threaded programs though.
5851 * Changes in MIPS configurations.
5853 Multi-arch support is enabled for all MIPS configurations.
5855 GDB can now be built as native debugger on SGI Irix 6.x systems for
5856 debugging n32 executables. (Debugging 64-bit executables is not yet
5859 * Unified support for hardware watchpoints in all x86 configurations.
5861 Most (if not all) native x86 configurations support hardware-assisted
5862 breakpoints and watchpoints in a unified manner. This support
5863 implements debug register sharing between watchpoints, which allows to
5864 put a virtually infinite number of watchpoints on the same address,
5865 and also supports watching regions up to 16 bytes with several debug
5868 The new maintenance command `maintenance show-debug-regs' toggles
5869 debugging print-outs in functions that insert, remove, and test
5870 watchpoints and hardware breakpoints.
5872 * Changes in the DJGPP native configuration.
5874 New command ``info dos sysinfo'' displays assorted information about
5875 the CPU, OS, memory, and DPMI server.
5877 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5878 display information about segment descriptors stored in GDT, LDT, and
5881 New commands ``info dos pde'' and ``info dos pte'' display entries
5882 from Page Directory and Page Tables (for now works with CWSDPMI only).
5883 New command ``info dos address-pte'' displays the Page Table entry for
5884 a given linear address.
5886 GDB can now pass command lines longer than 126 characters to the
5887 program being debugged (requires an update to the libdbg.a library
5888 which is part of the DJGPP development kit).
5890 DWARF2 debug info is now supported.
5892 It is now possible to `step' and `next' through calls to `longjmp'.
5894 * Changes in documentation.
5896 All GDB documentation was converted to GFDL, the GNU Free
5897 Documentation License.
5899 Tracepoints-related commands are now fully documented in the GDB
5902 TUI, the Text-mode User Interface, is now documented in the manual.
5904 Tracepoints-related commands are now fully documented in the GDB
5907 The "GDB Internals" manual now has an index. It also includes
5908 documentation of `ui_out' functions, GDB coding standards, x86
5909 hardware watchpoints, and memory region attributes.
5911 * GDB's version number moved to ``version.in''
5913 The Makefile variable VERSION has been replaced by the file
5914 ``version.in''. People creating GDB distributions should update the
5915 contents of this file.
5919 GUD support is now a standard part of the EMACS distribution.
5921 *** Changes in GDB 5.0:
5923 * Improved support for debugging FP programs on x86 targets
5925 Unified and much-improved support for debugging floating-point
5926 programs on all x86 targets. In particular, ``info float'' now
5927 displays the FP registers in the same format on all x86 targets, with
5928 greater level of detail.
5930 * Improvements and bugfixes in hardware-assisted watchpoints
5932 It is now possible to watch array elements, struct members, and
5933 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5934 on x86 targets no longer erroneously trigger when the address is
5937 * Improvements in the native DJGPP version of GDB
5939 The distribution now includes all the scripts and auxiliary files
5940 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5941 machines ``out of the box''.
5943 The DJGPP version can now debug programs that use signals. It is
5944 possible to catch signals that happened in the debuggee, deliver
5945 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5946 would kill the program being debugged.) Programs that hook hardware
5947 interrupts (keyboard, timer, etc.) can also be debugged.
5949 It is now possible to debug DJGPP programs that redirect their
5950 standard handles or switch them to raw (as opposed to cooked) mode, or
5951 even close them. The command ``run < foo > bar'' works as expected,
5952 and ``info terminal'' reports useful information about the debuggee's
5953 terminal, including raw/cooked mode, redirection, etc.
5955 The DJGPP version now uses termios functions for console I/O, which
5956 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5959 DOS-style file names with drive letters are now fully supported by
5962 It is now possible to debug DJGPP programs that switch their working
5963 directory. It is also possible to rerun the debuggee any number of
5964 times without restarting GDB; thus, you can use the same setup,
5965 breakpoints, etc. for many debugging sessions.
5967 * New native configurations
5969 ARM GNU/Linux arm*-*-linux*
5970 PowerPC GNU/Linux powerpc-*-linux*
5974 Motorola MCore mcore-*-*
5975 x86 VxWorks i[3456]86-*-vxworks*
5976 PowerPC VxWorks powerpc-*-vxworks*
5977 TI TMS320C80 tic80-*-*
5979 * OBSOLETE configurations
5981 Altos 3068 m68*-altos-*
5982 Convex c1-*-*, c2-*-*
5984 ARM RISCix arm-*-* (as host)
5987 Configurations that have been declared obsolete will be commented out,
5988 but the code will be left in place. If there is no activity to revive
5989 these configurations before the next release of GDB, the sources will
5990 be permanently REMOVED.
5992 * Gould support removed
5994 Support for the Gould PowerNode and NP1 has been removed.
5996 * New features for SVR4
5998 On SVR4 native platforms (such as Solaris), if you attach to a process
5999 without first loading a symbol file, GDB will now attempt to locate and
6000 load symbols from the running process's executable file.
6002 * Many C++ enhancements
6004 C++ support has been greatly improved. Overload resolution now works properly
6005 in almost all cases. RTTI support is on the way.
6007 * Remote targets can connect to a sub-program
6009 A popen(3) style serial-device has been added. This device starts a
6010 sub-process (such as a stand-alone simulator) and then communicates
6011 with that. The sub-program to run is specified using the syntax
6012 ``|<program> <args>'' vis:
6014 (gdb) set remotedebug 1
6015 (gdb) target extended-remote |mn10300-elf-sim program-args
6017 * MIPS 64 remote protocol
6019 A long standing bug in the mips64 remote protocol where by GDB
6020 expected certain 32 bit registers (ex SR) to be transfered as 32
6021 instead of 64 bits has been fixed.
6023 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6024 added to provide backward compatibility with older versions of GDB.
6026 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6028 The command ``set remotebinarydownload'' command has been replaced by
6029 ``set remote X-packet''. Other commands in ``set remote'' family
6030 include ``set remote P-packet''.
6032 * Breakpoint commands accept ranges.
6034 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6035 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6036 ``tracepoint passcount'' also accepts a range of tracepoints.
6038 * ``apropos'' command added.
6040 The ``apropos'' command searches through command names and
6041 documentation strings, printing out matches, making it much easier to
6042 try to find a command that does what you are looking for.
6046 A new machine oriented interface (MI) has been added to GDB. This
6047 interface is designed for debug environments running GDB as a separate
6048 process. This is part of the long term libGDB project. See the
6049 "GDB/MI" chapter of the GDB manual for further information. It can be
6050 enabled by configuring with:
6052 .../configure --enable-gdbmi
6054 *** Changes in GDB-4.18:
6056 * New native configurations
6058 HP-UX 10.20 hppa*-*-hpux10.20
6059 HP-UX 11.x hppa*-*-hpux11.0*
6060 M68K GNU/Linux m68*-*-linux*
6064 Fujitsu FR30 fr30-*-elf*
6065 Intel StrongARM strongarm-*-*
6066 Mitsubishi D30V d30v-*-*
6068 * OBSOLETE configurations
6070 Gould PowerNode, NP1 np1-*-*, pn-*-*
6072 Configurations that have been declared obsolete will be commented out,
6073 but the code will be left in place. If there is no activity to revive
6074 these configurations before the next release of GDB, the sources will
6075 be permanently REMOVED.
6079 As a compatibility experiment, GDB's source files buildsym.h and
6080 buildsym.c have been converted to pure standard C, no longer
6081 containing any K&R compatibility code. We believe that all systems in
6082 use today either come with a standard C compiler, or have a GCC port
6083 available. If this is not true, please report the affected
6084 configuration to bug-gdb@gnu.org immediately. See the README file for
6085 information about getting a standard C compiler if you don't have one
6090 GDB now uses readline 2.2.
6092 * set extension-language
6094 You can now control the mapping between filename extensions and source
6095 languages by using the `set extension-language' command. For instance,
6096 you can ask GDB to treat .c files as C++ by saying
6097 set extension-language .c c++
6098 The command `info extensions' lists all of the recognized extensions
6099 and their associated languages.
6101 * Setting processor type for PowerPC and RS/6000
6103 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6104 you can use the `set processor' command to specify what variant of the
6105 PowerPC family you are debugging. The command
6109 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6110 following PowerPC and RS6000 variants:
6112 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6113 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6115 403GC IBM PowerPC 403GC
6116 505 Motorola PowerPC 505
6117 860 Motorola PowerPC 860 or 850
6118 601 Motorola PowerPC 601
6119 602 Motorola PowerPC 602
6120 603 Motorola/IBM PowerPC 603 or 603e
6121 604 Motorola PowerPC 604 or 604e
6122 750 Motorola/IBM PowerPC 750 or 750
6124 At the moment, this command just tells GDB what to name the
6125 special-purpose processor registers. Since almost all the affected
6126 registers are inaccessible to user-level programs, this command is
6127 only useful for remote debugging in its present form.
6131 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6132 more extensive support for HP-UX. Added features include shared
6133 library support, kernel threads and hardware watchpoints for 11.00,
6134 support for HP's ANSI C and C++ compilers, and a compatibility mode
6135 for xdb and dbx commands.
6139 HP's donation includes the new concept of catchpoints, which is a
6140 generalization of the old catch command. On HP-UX, it is now possible
6141 to catch exec, fork, and vfork, as well as library loading.
6143 This means that the existing catch command has changed; its first
6144 argument now specifies the type of catch to be set up. See the
6145 output of "help catch" for a list of catchpoint types.
6147 * Debugging across forks
6149 On HP-UX, you can choose which process to debug when a fork() happens
6154 HP has donated a curses-based terminal user interface (TUI). To get
6155 it, build with --enable-tui. Although this can be enabled for any
6156 configuration, at present it only works for native HP debugging.
6158 * GDB remote protocol additions
6160 A new protocol packet 'X' that writes binary data is now available.
6161 Default behavior is to try 'X', then drop back to 'M' if the stub
6162 fails to respond. The settable variable `remotebinarydownload'
6163 allows explicit control over the use of 'X'.
6165 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6166 full 64-bit address. The command
6168 set remoteaddresssize 32
6170 can be used to revert to the old behaviour. For existing remote stubs
6171 the change should not be noticed, as the additional address information
6174 In order to assist in debugging stubs, you may use the maintenance
6175 command `packet' to send any text string to the stub. For instance,
6177 maint packet heythere
6179 sends the packet "$heythere#<checksum>". Note that it is very easy to
6180 disrupt a debugging session by sending the wrong packet at the wrong
6183 The compare-sections command allows you to compare section data on the
6184 target to what is in the executable file without uploading or
6185 downloading, by comparing CRC checksums.
6187 * Tracing can collect general expressions
6189 You may now collect general expressions at tracepoints. This requires
6190 further additions to the target-side stub; see tracepoint.c and
6191 doc/agentexpr.texi for further details.
6193 * mask-address variable for Mips
6195 For Mips targets, you may control the zeroing of the upper 32 bits of
6196 a 64-bit address by entering `set mask-address on'. This is mainly
6197 of interest to users of embedded R4xxx and R5xxx processors.
6199 * Higher serial baud rates
6201 GDB's serial code now allows you to specify baud rates 57600, 115200,
6202 230400, and 460800 baud. (Note that your host system may not be able
6203 to achieve all of these rates.)
6207 The i960 configuration now includes an initial implementation of a
6208 builtin simulator, contributed by Jim Wilson.
6211 *** Changes in GDB-4.17:
6213 * New native configurations
6215 Alpha GNU/Linux alpha*-*-linux*
6216 Unixware 2.x i[3456]86-unixware2*
6217 Irix 6.x mips*-sgi-irix6*
6218 PowerPC GNU/Linux powerpc-*-linux*
6219 PowerPC Solaris powerpcle-*-solaris*
6220 Sparc GNU/Linux sparc-*-linux*
6221 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6225 Argonaut Risc Chip (ARC) arc-*-*
6226 Hitachi H8/300S h8300*-*-*
6227 Matsushita MN10200 w/simulator mn10200-*-*
6228 Matsushita MN10300 w/simulator mn10300-*-*
6229 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6230 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6231 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6232 Mitsubishi D10V w/simulator d10v-*-*
6233 Mitsubishi M32R/D w/simulator m32r-*-elf*
6234 Tsqware Sparclet sparclet-*-*
6235 NEC V850 w/simulator v850-*-*
6237 * New debugging protocols
6239 ARM with RDI protocol arm*-*-*
6240 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6241 DDB and LSI variants of PMON protocol mips*-*-*
6242 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6243 PowerPC with SDS protocol powerpc{,le}-*-eabi
6244 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6248 All configurations can now understand and use the DWARF 2 debugging
6249 format. The choice is automatic, if the symbol file contains DWARF 2
6254 GDB now includes basic Java language support. This support is
6255 only useful with Java compilers that produce native machine code.
6257 * solib-absolute-prefix and solib-search-path
6259 For SunOS and SVR4 shared libraries, you may now set the prefix for
6260 loading absolute shared library symbol files, and the search path for
6261 locating non-absolute shared library symbol files.
6263 * Live range splitting
6265 GDB can now effectively debug code for which GCC has performed live
6266 range splitting as part of its optimization. See gdb/doc/LRS for
6267 more details on the expected format of the stabs information.
6271 GDB's support for the GNU Hurd, including thread debugging, has been
6272 updated to work with current versions of the Hurd.
6276 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6277 instruction set. ARM GDB automatically detects when Thumb
6278 instructions are in use, and adjusts disassembly and backtracing
6283 GDB's MIPS target configurations now handle the MIP16 16-bit
6288 GDB now includes support for overlays; if an executable has been
6289 linked such that multiple sections are based at the same address, GDB
6290 will decide which section to use for symbolic info. You can choose to
6291 control the decision manually, using overlay commands, or implement
6292 additional target-side support and use "overlay load-target" to bring
6293 in the overlay mapping. Do "help overlay" for more detail.
6297 The command "info symbol <address>" displays information about
6298 the symbol at the specified address.
6302 The standard remote protocol now includes an extension that allows
6303 asynchronous collection and display of trace data. This requires
6304 extensive support in the target-side debugging stub. Tracing mode
6305 includes a new interaction mode in GDB and new commands: see the
6306 file tracepoint.c for more details.
6310 Configurations for embedded MIPS now include a simulator contributed
6311 by Cygnus Solutions. The simulator supports the instruction sets
6312 of most MIPS variants.
6316 Sparc configurations may now include the ERC32 simulator contributed
6317 by the European Space Agency. The simulator is not built into
6318 Sparc targets by default; configure with --enable-sim to include it.
6322 For target configurations that may include multiple variants of a
6323 basic architecture (such as MIPS and SH), you may now set the
6324 architecture explicitly. "set arch" sets, "info arch" lists
6325 the possible architectures.
6327 *** Changes in GDB-4.16:
6329 * New native configurations
6331 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6332 M68K NetBSD m68k-*-netbsd*
6333 PowerPC AIX 4.x powerpc-*-aix*
6334 PowerPC MacOS powerpc-*-macos*
6335 PowerPC Windows NT powerpcle-*-cygwin32
6336 RS/6000 AIX 4.x rs6000-*-aix4*
6340 ARM with RDP protocol arm-*-*
6341 I960 with MON960 i960-*-coff
6342 MIPS VxWorks mips*-*-vxworks*
6343 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6344 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6346 Matra Sparclet sparclet-*-*
6350 The powerpc-eabi configuration now includes the PSIM simulator,
6351 contributed by Andrew Cagney, with assistance from Mike Meissner.
6352 PSIM is a very elaborate model of the PowerPC, including not only
6353 basic instruction set execution, but also details of execution unit
6354 performance and I/O hardware. See sim/ppc/README for more details.
6358 GDB now works with Solaris 2.5.
6360 * Windows 95/NT native
6362 GDB will now work as a native debugger on Windows 95 and Windows NT.
6363 To build it from source, you must use the "gnu-win32" environment,
6364 which uses a DLL to emulate enough of Unix to run the GNU tools.
6365 Further information, binaries, and sources are available at
6366 ftp.cygnus.com, under pub/gnu-win32.
6368 * dont-repeat command
6370 If a user-defined command includes the command `dont-repeat', then the
6371 command will not be repeated if the user just types return. This is
6372 useful if the command is time-consuming to run, so that accidental
6373 extra keystrokes don't run the same command many times.
6375 * Send break instead of ^C
6377 The standard remote protocol now includes an option to send a break
6378 rather than a ^C to the target in order to interrupt it. By default,
6379 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6381 * Remote protocol timeout
6383 The standard remote protocol includes a new variable `remotetimeout'
6384 that allows you to set the number of seconds before GDB gives up trying
6385 to read from the target. The default value is 2.
6387 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6389 By default GDB will automatically keep track of objects as they are
6390 loaded and unloaded by the dynamic linker. By using the command `set
6391 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6392 when shared library events occur, thus allowing you to set breakpoints
6393 in shared libraries which are explicitly loaded by the inferior.
6395 Note this feature does not work on hpux8. On hpux9 you must link
6396 /usr/lib/end.o into your program. This feature should work
6397 automatically on hpux10.
6399 * Irix 5.x hardware watchpoint support
6401 Irix 5 configurations now support the use of hardware watchpoints.
6403 * Mips protocol "SYN garbage limit"
6405 When debugging a Mips target using the `target mips' protocol, you
6406 may set the number of characters that GDB will ignore by setting
6407 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6408 every character. The default value is 1050.
6410 * Recording and replaying remote debug sessions
6412 If you set `remotelogfile' to the name of a file, gdb will write to it
6413 a recording of a remote debug session. This recording may then be
6414 replayed back to gdb using "gdbreplay". See gdbserver/README for
6415 details. This is useful when you have a problem with GDB while doing
6416 remote debugging; you can make a recording of the session and send it
6417 to someone else, who can then recreate the problem.
6419 * Speedups for remote debugging
6421 GDB includes speedups for downloading and stepping MIPS systems using
6422 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6423 and more efficient S-record downloading.
6425 * Memory use reductions and statistics collection
6427 GDB now uses less memory and reports statistics about memory usage.
6428 Try the `maint print statistics' command, for example.
6430 *** Changes in GDB-4.15:
6432 * Psymtabs for XCOFF
6434 The symbol reader for AIX GDB now uses partial symbol tables. This
6435 can greatly improve startup time, especially for large executables.
6437 * Remote targets use caching
6439 Remote targets now use a data cache to speed up communication with the
6440 remote side. The data cache could lead to incorrect results because
6441 it doesn't know about volatile variables, thus making it impossible to
6442 debug targets which use memory mapped I/O devices. `set remotecache
6443 off' turns the the data cache off.
6445 * Remote targets may have threads
6447 The standard remote protocol now includes support for multiple threads
6448 in the target system, using new protocol commands 'H' and 'T'. See
6449 gdb/remote.c for details.
6453 If GDB is configured with `--enable-netrom', then it will include
6454 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6455 acts as though it is a bank of ROM on the target board, but you can
6456 write into it over the network. GDB's support consists only of
6457 support for fast loading into the emulated ROM; to debug, you must use
6458 another protocol, such as standard remote protocol. The usual
6459 sequence is something like
6461 target nrom <netrom-hostname>
6463 target remote <netrom-hostname>:1235
6467 GDB now includes support for the Apple Macintosh, as a host only. It
6468 may be run as either an MPW tool or as a standalone application, and
6469 it can debug through the serial port. All the usual GDB commands are
6470 available, but to the target command, you must supply "serial" as the
6471 device type instead of "/dev/ttyXX". See mpw-README in the main
6472 directory for more information on how to build. The MPW configuration
6473 scripts */mpw-config.in support only a few targets, and only the
6474 mips-idt-ecoff target has been tested.
6478 GDB configuration now uses autoconf. This is not user-visible,
6479 but does simplify configuration and building.
6483 GDB now supports hpux10.
6485 *** Changes in GDB-4.14:
6487 * New native configurations
6489 x86 FreeBSD i[345]86-*-freebsd
6490 x86 NetBSD i[345]86-*-netbsd
6491 NS32k NetBSD ns32k-*-netbsd
6492 Sparc NetBSD sparc-*-netbsd
6496 A29K VxWorks a29k-*-vxworks
6497 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6498 CPU32 EST-300 emulator m68*-*-est*
6499 PowerPC ELF powerpc-*-elf
6502 * Alpha OSF/1 support for procfs
6504 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6505 possible to attach to running processes. As the mounting of the /proc
6506 filesystem is optional on the Alpha, GDB automatically determines
6507 the availability of /proc during startup. This can lead to problems
6508 if /proc is unmounted after GDB has been started.
6510 * Arguments to user-defined commands
6512 User commands may accept up to 10 arguments separated by whitespace.
6513 Arguments are accessed within the user command via $arg0..$arg9. A
6516 print $arg0 + $arg1 + $arg2
6518 To execute the command use:
6521 Defines the command "adder" which prints the sum of its three arguments.
6522 Note the arguments are text substitutions, so they may reference variables,
6523 use complex expressions, or even perform inferior function calls.
6525 * New `if' and `while' commands
6527 This makes it possible to write more sophisticated user-defined
6528 commands. Both commands take a single argument, which is the
6529 expression to evaluate, and must be followed by the commands to
6530 execute, one per line, if the expression is nonzero, the list being
6531 terminated by the word `end'. The `if' command list may include an
6532 `else' word, which causes the following commands to be executed only
6533 if the expression is zero.
6535 * Fortran source language mode
6537 GDB now includes partial support for Fortran 77. It will recognize
6538 Fortran programs and can evaluate a subset of Fortran expressions, but
6539 variables and functions may not be handled correctly. GDB will work
6540 with G77, but does not yet know much about symbols emitted by other
6543 * Better HPUX support
6545 Most debugging facilities now work on dynamic executables for HPPAs
6546 running hpux9 or later. You can attach to running dynamically linked
6547 processes, but by default the dynamic libraries will be read-only, so
6548 for instance you won't be able to put breakpoints in them. To change
6549 that behavior do the following before running the program:
6555 This will cause the libraries to be mapped private and read-write.
6556 To revert to the normal behavior, do this:
6562 You cannot set breakpoints or examine data in the library until after
6563 the library is loaded if the function/data symbols do not have
6566 GDB can now also read debug symbols produced by the HP C compiler on
6567 HPPAs (sorry, no C++, Fortran or 68k support).
6569 * Target byte order now dynamically selectable
6571 You can choose which byte order to use with a target system, via the
6572 commands "set endian big" and "set endian little", and you can see the
6573 current setting by using "show endian". You can also give the command
6574 "set endian auto", in which case GDB will use the byte order
6575 associated with the executable. Currently, only embedded MIPS
6576 configurations support dynamic selection of target byte order.
6578 * New DOS host serial code
6580 This version uses DPMI interrupts to handle buffered I/O, so you
6581 no longer need to run asynctsr when debugging boards connected to
6584 *** Changes in GDB-4.13:
6586 * New "complete" command
6588 This lists all the possible completions for the rest of the line, if it
6589 were to be given as a command itself. This is intended for use by emacs.
6591 * Trailing space optional in prompt
6593 "set prompt" no longer adds a space for you after the prompt you set. This
6594 allows you to set a prompt which ends in a space or one that does not.
6596 * Breakpoint hit counts
6598 "info break" now displays a count of the number of times the breakpoint
6599 has been hit. This is especially useful in conjunction with "ignore"; you
6600 can ignore a large number of breakpoint hits, look at the breakpoint info
6601 to see how many times the breakpoint was hit, then run again, ignoring one
6602 less than that number, and this will get you quickly to the last hit of
6605 * Ability to stop printing at NULL character
6607 "set print null-stop" will cause GDB to stop printing the characters of
6608 an array when the first NULL is encountered. This is useful when large
6609 arrays actually contain only short strings.
6611 * Shared library breakpoints
6613 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6614 breakpoints in shared libraries before the executable is run.
6616 * Hardware watchpoints
6618 There is a new hardware breakpoint for the watch command for sparclite
6619 targets. See gdb/sparclite/hw_breakpoint.note.
6621 Hardware watchpoints are also now supported under GNU/Linux.
6625 Annotations have been added. These are for use with graphical interfaces,
6626 and are still experimental. Currently only gdba.el uses these.
6628 * Improved Irix 5 support
6630 GDB now works properly with Irix 5.2.
6632 * Improved HPPA support
6634 GDB now works properly with the latest GCC and GAS.
6636 * New native configurations
6638 Sequent PTX4 i[34]86-sequent-ptx4
6639 HPPA running OSF/1 hppa*-*-osf*
6640 Atari TT running SVR4 m68*-*-sysv4*
6641 RS/6000 LynxOS rs6000-*-lynxos*
6645 OS/9000 i[34]86-*-os9k
6646 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6649 * Hitachi SH7000 and E7000-PC ICE support
6651 There is now support for communicating with the Hitachi E7000-PC ICE.
6652 This is available automatically when GDB is configured for the SH.
6656 As usual, a variety of small fixes and improvements, both generic
6657 and configuration-specific. See the ChangeLog for more detail.
6659 *** Changes in GDB-4.12:
6661 * Irix 5 is now supported
6665 GDB-4.12 on the HPPA has a number of changes which make it unable
6666 to debug the output from the currently released versions of GCC and
6667 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6668 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6669 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6672 *** Changes in GDB-4.11:
6674 * User visible changes:
6678 The "set remotedebug" option is now consistent between the mips remote
6679 target, remote targets using the gdb-specific protocol, UDI (AMD's
6680 debug protocol for the 29k) and the 88k bug monitor. It is now an
6681 integer specifying a debug level (normally 0 or 1, but 2 means more
6682 debugging info for the mips target).
6684 * DEC Alpha native support
6686 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6687 debug info, but GDB works fairly well with the DEC compiler and should
6688 work with a future GCC release. See the README file for a few
6689 Alpha-specific notes.
6691 * Preliminary thread implementation
6693 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6695 * LynxOS native and target support for 386
6697 This release has been hosted on LynxOS 2.2, and also can be configured
6698 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6701 * Improvements in C++ mangling/demangling.
6703 This release has much better g++ debugging, specifically in name
6704 mangling/demangling, virtual function calls, print virtual table,
6705 call methods, ...etc.
6707 *** Changes in GDB-4.10:
6709 * User visible changes:
6711 Remote debugging using the GDB-specific (`target remote') protocol now
6712 supports the `load' command. This is only useful if you have some
6713 other way of getting the stub to the target system, and you can put it
6714 somewhere in memory where it won't get clobbered by the download.
6716 Filename completion now works.
6718 When run under emacs mode, the "info line" command now causes the
6719 arrow to point to the line specified. Also, "info line" prints
6720 addresses in symbolic form (as well as hex).
6722 All vxworks based targets now support a user settable option, called
6723 vxworks-timeout. This option represents the number of seconds gdb
6724 should wait for responses to rpc's. You might want to use this if
6725 your vxworks target is, perhaps, a slow software simulator or happens
6726 to be on the far side of a thin network line.
6730 This release contains support for using a DEC alpha as a GDB host for
6731 cross debugging. Native alpha debugging is not supported yet.
6734 *** Changes in GDB-4.9:
6738 This is the first GDB release which is accompanied by a matching testsuite.
6739 The testsuite requires installation of dejagnu, which should be available
6740 via ftp from most sites that carry GNU software.
6744 'Cfront' style demangling has had its name changed to 'ARM' style, to
6745 emphasize that it was written from the specifications in the C++ Annotated
6746 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6747 disclaimers, it still generated too much confusion with users attempting to
6748 use gdb with AT&T cfront.
6752 GDB now uses a standard remote interface to a simulator library.
6753 So far, the library contains simulators for the Zilog Z8001/2, the
6754 Hitachi H8/300, H8/500 and Super-H.
6756 * New targets supported
6758 H8/300 simulator h8300-hitachi-hms or h8300hms
6759 H8/500 simulator h8500-hitachi-hms or h8500hms
6760 SH simulator sh-hitachi-hms or sh
6761 Z8000 simulator z8k-zilog-none or z8ksim
6762 IDT MIPS board over serial line mips-idt-ecoff
6764 Cross-debugging to GO32 targets is supported. It requires a custom
6765 version of the i386-stub.c module which is integrated with the
6766 GO32 memory extender.
6768 * New remote protocols
6770 MIPS remote debugging protocol.
6772 * New source languages supported
6774 This version includes preliminary support for Chill, a Pascal like language
6775 used by telecommunications companies. Chill support is also being integrated
6776 into the GNU compiler, but we don't know when it will be publically available.
6779 *** Changes in GDB-4.8:
6781 * HP Precision Architecture supported
6783 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6784 version of this support was available as a set of patches from the
6785 University of Utah. GDB does not support debugging of programs
6786 compiled with the HP compiler, because HP will not document their file
6787 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6788 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6790 Many problems in the preliminary version have been fixed.
6792 * Faster and better demangling
6794 We have improved template demangling and fixed numerous bugs in the GNU style
6795 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6796 character types (wchar_t) are now supported. Demangling of each symbol is now
6797 only done once, and is cached when the symbol table for a file is read in.
6798 This results in a small increase in memory usage for C programs, a moderate
6799 increase in memory usage for C++ programs, and a fantastic speedup in
6802 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6803 from the specifications in the Annotated Reference Manual, which AT&T's
6804 compiler does not actually implement.
6806 * G++ multiple inheritance compiler problem
6808 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6809 inheritance lattices was reworked to properly discover ambiguities. We
6810 recently found an example which causes this new algorithm to fail in a
6811 very subtle way, producing bad debug information for those classes.
6812 The file 'gcc.patch' (in this directory) can be applied to gcc to
6813 circumvent the problem. A future GCC release will contain a complete
6816 The previous G++ debug info problem (mentioned below for the gdb-4.7
6817 release) is fixed in gcc version 2.3.2.
6819 * Improved configure script
6821 The `configure' script will now attempt to guess your system type if
6822 you don't supply a host system type. The old scheme of supplying a
6823 host system triplet is preferable over using this. All the magic is
6824 done in the new `config.guess' script. Examine it for details.
6826 We have also brought our configure script much more in line with the FSF's
6827 version. It now supports the --with-xxx options. In particular,
6828 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6829 The resulting GDB will not be able to read arbitrary object file formats --
6830 only the format ``expected'' to be used on the configured target system.
6831 We hope to make this the default in a future release.
6833 * Documentation improvements
6835 There's new internal documentation on how to modify GDB, and how to
6836 produce clean changes to the code. We implore people to read it
6837 before submitting changes.
6839 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6840 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6841 `info' files are also provided. To build `info' files from scratch,
6842 you will need the latest `makeinfo' release, which will be available in
6843 a future texinfo-X.Y release.
6845 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6846 We're not sure exactly which versions have this problem, but it has
6847 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6848 or better. If that isn't possible, there is a patch in
6849 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6850 around this problem.
6854 GDB now supports array constants that can be used in expressions typed in by
6855 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6856 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6859 The new directory `gdb/sparclite' contains a program that demonstrates
6860 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6862 * New native hosts supported
6864 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6865 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6867 * New targets supported
6869 AMD 29k family via UDI a29k-amd-udi or udi29k
6871 * New file formats supported
6873 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6874 HPUX core files, and SCO 3.2v2 core files.
6878 Attaching to processes now works again; thanks for the many bug reports.
6880 We have also stomped on a bunch of core dumps caused by
6881 printf_filtered("%s") problems.
6883 We eliminated a copyright problem on the rpc and ptrace header files
6884 for VxWorks, which was discovered at the last minute during the 4.7
6885 release. You should now be able to build a VxWorks GDB.
6887 You can now interrupt gdb while an attached process is running. This
6888 will cause the attached process to stop, and give control back to GDB.
6890 We fixed problems caused by using too many file descriptors
6891 for reading symbols from object files and libraries. This was
6892 especially a problem for programs that used many (~100) shared
6895 The `step' command now only enters a subroutine if there is line number
6896 information for the subroutine. Otherwise it acts like the `next'
6897 command. Previously, `step' would enter subroutines if there was
6898 any debugging information about the routine. This avoids problems
6899 when using `cc -g1' on MIPS machines.
6901 * Internal improvements
6903 GDB's internal interfaces have been improved to make it easier to support
6904 debugging of multiple languages in the future.
6906 GDB now uses a common structure for symbol information internally.
6907 Minimal symbols (derived from linkage symbols in object files), partial
6908 symbols (from a quick scan of debug information), and full symbols
6909 contain a common subset of information, making it easier to write
6910 shared code that handles any of them.
6912 * New command line options
6914 We now accept --silent as an alias for --quiet.
6918 The memory-mapped-malloc library is now licensed under the GNU Library
6919 General Public License.
6921 *** Changes in GDB-4.7:
6923 * Host/native/target split
6925 GDB has had some major internal surgery to untangle the support for
6926 hosts and remote targets. Now, when you configure GDB for a remote
6927 target, it will no longer load in all of the support for debugging
6928 local programs on the host. When fully completed and tested, this will
6929 ensure that arbitrary host/target combinations are possible.
6931 The primary conceptual shift is to separate the non-portable code in
6932 GDB into three categories. Host specific code is required any time GDB
6933 is compiled on that host, regardless of the target. Target specific
6934 code relates to the peculiarities of the target, but can be compiled on
6935 any host. Native specific code is everything else: it can only be
6936 built when the host and target are the same system. Child process
6937 handling and core file support are two common `native' examples.
6939 GDB's use of /proc for controlling Unix child processes is now cleaner.
6940 It has been split out into a single module under the `target_ops' vector,
6941 plus two native-dependent functions for each system that uses /proc.
6943 * New hosts supported
6945 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6946 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6947 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6949 * New targets supported
6951 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6952 68030 and CPU32 m68030-*-*, m68332-*-*
6954 * New native hosts supported
6956 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6957 (386bsd is not well tested yet)
6958 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6960 * New file formats supported
6962 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6963 supports reading of `a.out.adobe' object files, which are an a.out
6964 format extended with minimal information about multiple sections.
6968 `show copying' is the same as the old `info copying'.
6969 `show warranty' is the same as `info warrantee'.
6970 These were renamed for consistency. The old commands continue to work.
6972 `info handle' is a new alias for `info signals'.
6974 You can now define pre-command hooks, which attach arbitrary command
6975 scripts to any command. The commands in the hook will be executed
6976 prior to the user's command. You can also create a hook which will be
6977 executed whenever the program stops. See gdb.texinfo.
6981 We now deal with Cfront style name mangling, and can even extract type
6982 info from mangled symbols. GDB can automatically figure out which
6983 symbol mangling style your C++ compiler uses.
6985 Calling of methods and virtual functions has been improved as well.
6989 The crash that occured when debugging Sun Ansi-C compiled binaries is
6990 fixed. This was due to mishandling of the extra N_SO stabs output
6993 We also finally got Ultrix 4.2 running in house, and fixed core file
6994 support, with help from a dozen people on the net.
6996 John M. Farrell discovered that the reason that single-stepping was so
6997 slow on all of the Mips based platforms (primarily SGI and DEC) was
6998 that we were trying to demangle and lookup a symbol used for internal
6999 purposes on every instruction that was being stepped through. Changing
7000 the name of that symbol so that it couldn't be mistaken for a C++
7001 mangled symbol sped things up a great deal.
7003 Rich Pixley sped up symbol lookups in general by getting much smarter
7004 about when C++ symbol mangling is necessary. This should make symbol
7005 completion (TAB on the command line) much faster. It's not as fast as
7006 we'd like, but it's significantly faster than gdb-4.6.
7010 A new user controllable variable 'call_scratch_address' can
7011 specify the location of a scratch area to be used when GDB
7012 calls a function in the target. This is necessary because the
7013 usual method of putting the scratch area on the stack does not work
7014 in systems that have separate instruction and data spaces.
7016 We integrated changes to support the 29k UDI (Universal Debugger
7017 Interface), but discovered at the last minute that we didn't have all
7018 of the appropriate copyright paperwork. We are working with AMD to
7019 resolve this, and hope to have it available soon.
7023 We have sped up the remote serial line protocol, especially for targets
7024 with lots of registers. It now supports a new `expedited status' ('T')
7025 message which can be used in place of the existing 'S' status message.
7026 This allows the remote stub to send only the registers that GDB
7027 needs to make a quick decision about single-stepping or conditional
7028 breakpoints, eliminating the need to fetch the entire register set for
7029 each instruction being stepped through.
7031 The GDB remote serial protocol now implements a write-through cache for
7032 registers, only re-reading the registers if the target has run.
7034 There is also a new remote serial stub for SPARC processors. You can
7035 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7036 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7037 processor with a serial port.
7041 Configure.in files have become much easier to read and modify. A new
7042 `table driven' format makes it more obvious what configurations are
7043 supported, and what files each one uses.
7047 There is a new opcodes library which will eventually contain all of the
7048 disassembly routines and opcode tables. At present, it only contains
7049 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7050 disassembler (binutils/objdump) to share these routines.
7052 The libiberty library is now copylefted under the GNU Library General
7053 Public License. This allows more liberal use, and was done so libg++
7054 can use it. This makes no difference to GDB, since the Library License
7055 grants all the rights from the General Public License.
7059 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7060 reference to the stabs symbol info used by the debugger. It is (as far
7061 as we know) the only published document on this fascinating topic. We
7062 encourage you to read it, compare it to the stabs information on your
7063 system, and send improvements on the document in general (to
7064 bug-gdb@prep.ai.mit.edu).
7066 And, of course, many bugs have been fixed.
7069 *** Changes in GDB-4.6:
7071 * Better support for C++ function names
7073 GDB now accepts as input the "demangled form" of C++ overloaded function
7074 names and member function names, and can do command completion on such names
7075 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7076 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7077 Make use of command completion, it is your friend.
7079 GDB also now accepts a variety of C++ mangled symbol formats. They are
7080 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7081 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7082 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7083 for the list of formats.
7085 * G++ symbol mangling problem
7087 Recent versions of gcc have a bug in how they emit debugging information for
7088 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7089 directory) can be applied to gcc to fix the problem. Alternatively, if you
7090 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7091 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7092 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7095 * New 'maintenance' command
7097 All of the commands related to hacking GDB internals have been moved out of
7098 the main command set, and now live behind the 'maintenance' command. This
7099 can also be abbreviated as 'mt'. The following changes were made:
7101 dump-me -> maintenance dump-me
7102 info all-breakpoints -> maintenance info breakpoints
7103 printmsyms -> maintenance print msyms
7104 printobjfiles -> maintenance print objfiles
7105 printpsyms -> maintenance print psymbols
7106 printsyms -> maintenance print symbols
7108 The following commands are new:
7110 maintenance demangle Call internal GDB demangler routine to
7111 demangle a C++ link name and prints the result.
7112 maintenance print type Print a type chain for a given symbol
7114 * Change to .gdbinit file processing
7116 We now read the $HOME/.gdbinit file before processing the argv arguments
7117 (e.g. reading symbol files or core files). This allows global parameters to
7118 be set, which will apply during the symbol reading. The ./.gdbinit is still
7119 read after argv processing.
7121 * New hosts supported
7123 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7125 GNU/Linux support i386-unknown-linux or linux
7127 We are also including code to support the HP/PA running BSD and HPUX. This
7128 is almost guaranteed not to work, as we didn't have time to test or build it
7129 for this release. We are including it so that the more adventurous (or
7130 masochistic) of you can play with it. We also had major problems with the
7131 fact that the compiler that we got from HP doesn't support the -g option.
7134 * New targets supported
7136 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7138 * More smarts about finding #include files
7140 GDB now remembers the compilation directory for all include files, and for
7141 all files from which C is generated (like yacc and lex sources). This
7142 greatly improves GDB's ability to find yacc/lex sources, and include files,
7143 especially if you are debugging your program from a directory different from
7144 the one that contains your sources.
7146 We also fixed a bug which caused difficulty with listing and setting
7147 breakpoints in include files which contain C code. (In the past, you had to
7148 try twice in order to list an include file that you hadn't looked at before.)
7150 * Interesting infernals change
7152 GDB now deals with arbitrary numbers of sections, where the symbols for each
7153 section must be relocated relative to that section's landing place in the
7154 target's address space. This work was needed to support ELF with embedded
7155 stabs used by Solaris-2.0.
7157 * Bug fixes (of course!)
7159 There have been loads of fixes for the following things:
7160 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7161 i960, stabs, DOS(GO32), procfs, etc...
7163 See the ChangeLog for details.
7165 *** Changes in GDB-4.5:
7167 * New machines supported (host and target)
7169 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7171 SGI Irix-4.x mips-sgi-irix4 or iris4
7173 * New malloc package
7175 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7176 Mmalloc is capable of handling mutiple heaps of memory. It is also
7177 capable of saving a heap to a file, and then mapping it back in later.
7178 This can be used to greatly speedup the startup of GDB by using a
7179 pre-parsed symbol table which lives in a mmalloc managed heap. For
7180 more details, please read mmalloc/mmalloc.texi.
7184 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7185 'help info proc' for details.
7187 * MIPS ecoff symbol table format
7189 The code that reads MIPS symbol table format is now supported on all hosts.
7190 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7193 * File name changes for MS-DOS
7195 Many files in the config directories have been renamed to make it easier to
7196 support GDB on MS-DOSe systems (which have very restrictive file name
7197 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7198 environment) is close to working but has some remaining problems. Note
7199 that debugging of DOS programs is not supported, due to limitations
7200 in the ``operating system'', but it can be used to host cross-debugging.
7202 * Cross byte order fixes
7204 Many fixes have been made to support cross debugging of Sparc and MIPS
7205 targets from hosts whose byte order differs.
7207 * New -mapped and -readnow options
7209 If memory-mapped files are available on your system through the 'mmap'
7210 system call, you can use the -mapped option on the `file' or
7211 `symbol-file' commands to cause GDB to write the symbols from your
7212 program into a reusable file. If the program you are debugging is
7213 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7214 Future GDB debugging sessions will notice the presence of this file,
7215 and will quickly map in symbol information from it, rather than reading
7216 the symbol table from the executable program. Using the '-mapped'
7217 option in a GDB `file' or `symbol-file' command has the same effect as
7218 starting GDB with the '-mapped' command-line option.
7220 You can cause GDB to read the entire symbol table immediately by using
7221 the '-readnow' option with any of the commands that load symbol table
7222 information (or on the GDB command line). This makes the command
7223 slower, but makes future operations faster.
7225 The -mapped and -readnow options are typically combined in order to
7226 build a `fred.syms' file that contains complete symbol information.
7227 A simple GDB invocation to do nothing but build a `.syms' file for future
7230 gdb -batch -nx -mapped -readnow programname
7232 The `.syms' file is specific to the host machine on which GDB is run.
7233 It holds an exact image of GDB's internal symbol table. It cannot be
7234 shared across multiple host platforms.
7236 * longjmp() handling
7238 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7239 siglongjmp() without losing control. This feature has not yet been ported to
7240 all systems. It currently works on many 386 platforms, all MIPS-based
7241 platforms (SGI, DECstation, etc), and Sun3/4.
7245 Preliminary work has been put in to support the new Solaris OS from Sun. At
7246 this time, it can control and debug processes, but it is not capable of
7251 As always, many many bug fixes. The major areas were with g++, and mipsread.
7252 People using the MIPS-based platforms should experience fewer mysterious
7253 crashes and trashed symbol tables.
7255 *** Changes in GDB-4.4:
7257 * New machines supported (host and target)
7259 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7261 BSD Reno on Vax vax-dec-bsd
7262 Ultrix on Vax vax-dec-ultrix
7264 * New machines supported (target)
7266 AMD 29000 embedded, using EBMON a29k-none-none
7270 GDB continues to improve its handling of C++. `References' work better.
7271 The demangler has also been improved, and now deals with symbols mangled as
7272 per the Annotated C++ Reference Guide.
7274 GDB also now handles `stabs' symbol information embedded in MIPS
7275 `ecoff' symbol tables. Since the ecoff format was not easily
7276 extensible to handle new languages such as C++, this appeared to be a
7277 good way to put C++ debugging info into MIPS binaries. This option
7278 will be supported in the GNU C compiler, version 2, when it is
7281 * New features for SVR4
7283 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7284 shared libraries. Debugging dynamically linked programs should present
7285 only minor differences from debugging statically linked programs.
7287 The `info proc' command will print out information about any process
7288 on an SVR4 system (including the one you are debugging). At the moment,
7289 it prints the address mappings of the process.
7291 If you bring up GDB on another SVR4 system, please send mail to
7292 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7294 * Better dynamic linking support in SunOS
7296 Reading symbols from shared libraries which contain debugging symbols
7297 now works properly. However, there remain issues such as automatic
7298 skipping of `transfer vector' code during function calls, which
7299 make it harder to debug code in a shared library, than to debug the
7300 same code linked statically.
7304 GDB is now using the latest `getopt' routines from the FSF. This
7305 version accepts the -- prefix for options with long names. GDB will
7306 continue to accept the old forms (-option and +option) as well.
7307 Various single letter abbreviations for options have been explicity
7308 added to the option table so that they won't get overshadowed in the
7309 future by other options that begin with the same letter.
7313 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7314 Many assorted bugs have been handled. Many more remain to be handled.
7315 See the various ChangeLog files (primarily in gdb and bfd) for details.
7318 *** Changes in GDB-4.3:
7320 * New machines supported (host and target)
7322 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7323 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7324 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7326 * Almost SCO Unix support
7328 We had hoped to support:
7329 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7330 (except for core file support), but we discovered very late in the release
7331 that it has problems with process groups that render gdb unusable. Sorry
7332 about that. I encourage people to fix it and post the fixes.
7334 * Preliminary ELF and DWARF support
7336 GDB can read ELF object files on System V Release 4, and can handle
7337 debugging records for C, in DWARF format, in ELF files. This support
7338 is preliminary. If you bring up GDB on another SVR4 system, please
7339 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7344 GDB now uses the latest `readline' library. One user-visible change
7345 is that two tabs will list possible command completions, which previously
7346 required typing M-? (meta-question mark, or ESC ?).
7350 The `stepi' bug that many of you noticed has been squashed.
7351 Many bugs in C++ have been handled. Many more remain to be handled.
7352 See the various ChangeLog files (primarily in gdb and bfd) for details.
7354 * State of the MIPS world (in case you wondered):
7356 GDB can understand the symbol tables emitted by the compilers
7357 supplied by most vendors of MIPS-based machines, including DEC. These
7358 symbol tables are in a format that essentially nobody else uses.
7360 Some versions of gcc come with an assembler post-processor called
7361 mips-tfile. This program is required if you want to do source-level
7362 debugging of gcc-compiled programs. I believe FSF does not ship
7363 mips-tfile with gcc version 1, but it will eventually come with gcc
7366 Debugging of g++ output remains a problem. g++ version 1.xx does not
7367 really support it at all. (If you're lucky, you should be able to get
7368 line numbers and stack traces to work, but no parameters or local
7369 variables.) With some work it should be possible to improve the
7372 When gcc version 2 is released, you will have somewhat better luck.
7373 However, even then you will get confusing results for inheritance and
7376 We will eventually provide full debugging of g++ output on
7377 DECstations. This will probably involve some kind of stabs-in-ecoff
7378 encapulation, but the details have not been worked out yet.
7381 *** Changes in GDB-4.2:
7383 * Improved configuration
7385 Only one copy of `configure' exists now, and it is not self-modifying.
7386 Porting BFD is simpler.
7390 The `step' and `next' commands now only stop at the first instruction
7391 of a source line. This prevents the multiple stops that used to occur
7392 in switch statements, for-loops, etc. `Step' continues to stop if a
7393 function that has debugging information is called within the line.
7397 Lots of small bugs fixed. More remain.
7399 * New host supported (not target)
7401 Intel 386 PC clone running Mach i386-none-mach
7404 *** Changes in GDB-4.1:
7406 * Multiple source language support
7408 GDB now has internal scaffolding to handle several source languages.
7409 It determines the type of each source file from its filename extension,
7410 and will switch expression parsing and number formatting to match the
7411 language of the function in the currently selected stack frame.
7412 You can also specifically set the language to be used, with
7413 `set language c' or `set language modula-2'.
7417 GDB now has preliminary support for the GNU Modula-2 compiler,
7418 currently under development at the State University of New York at
7419 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7420 continue through the fall of 1991 and into 1992.
7422 Other Modula-2 compilers are currently not supported, and attempting to
7423 debug programs compiled with them will likely result in an error as the
7424 symbol table is read. Feel free to work on it, though!
7426 There are hooks in GDB for strict type checking and range checking,
7427 in the `Modula-2 philosophy', but they do not currently work.
7431 GDB can now write to executable and core files (e.g. patch
7432 a variable's value). You must turn this switch on, specify
7433 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7434 by assigning a new value to a variable. Modifications take
7437 * Automatic SunOS shared library reading
7439 When you run your program, GDB automatically determines where its
7440 shared libraries (if any) have been loaded, and reads their symbols.
7441 The `share' command is no longer needed. This also works when
7442 examining core files.
7446 You can specify the number of lines that the `list' command shows.
7449 * New machines supported (host and target)
7451 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7452 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7453 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7455 * New hosts supported (not targets)
7457 IBM RT/PC: romp-ibm-aix or rtpc
7459 * New targets supported (not hosts)
7461 AMD 29000 embedded with COFF a29k-none-coff
7462 AMD 29000 embedded with a.out a29k-none-aout
7463 Ultracomputer remote kernel debug a29k-nyu-kern
7465 * New remote interfaces
7471 *** Changes in GDB-4.0:
7475 Wide output is wrapped at good places to make the output more readable.
7477 Gdb now supports cross-debugging from a host machine of one type to a
7478 target machine of another type. Communication with the target system
7479 is over serial lines. The ``target'' command handles connecting to the
7480 remote system; the ``load'' command will download a program into the
7481 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7482 also supports debugging of realtime processes running under VxWorks,
7483 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7484 stub on the target system.
7486 New CPUs supported include the AMD 29000 and Intel 960.
7488 GDB now reads object files and symbol tables via a ``binary file''
7489 library, which allows a single copy of GDB to debug programs of multiple
7490 object file types such as a.out and coff.
7492 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7493 refcard.dvi and refcard.ps are available to format it).
7496 * Control-Variable user interface simplified
7498 All variables that control the operation of the debugger can be set
7499 by the ``set'' command, and displayed by the ``show'' command.
7501 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7502 ``Show prompt'' produces the response:
7503 Gdb's prompt is new-gdb=>.
7505 What follows are the NEW set commands. The command ``help set'' will
7506 print a complete list of old and new set commands. ``help set FOO''
7507 will give a longer description of the variable FOO. ``show'' will show
7508 all of the variable descriptions and their current settings.
7510 confirm on/off: Enables warning questions for operations that are
7511 hard to recover from, e.g. rerunning the program while
7512 it is already running. Default is ON.
7514 editing on/off: Enables EMACS style command line editing
7515 of input. Previous lines can be recalled with
7516 control-P, the current line can be edited with control-B,
7517 you can search for commands with control-R, etc.
7520 history filename NAME: NAME is where the gdb command history
7521 will be stored. The default is .gdb_history,
7522 or the value of the environment variable
7525 history size N: The size, in commands, of the command history. The
7526 default is 256, or the value of the environment variable
7529 history save on/off: If this value is set to ON, the history file will
7530 be saved after exiting gdb. If set to OFF, the
7531 file will not be saved. The default is OFF.
7533 history expansion on/off: If this value is set to ON, then csh-like
7534 history expansion will be performed on
7535 command line input. The default is OFF.
7537 radix N: Sets the default radix for input and output. It can be set
7538 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7539 in the current radix, so "set radix 10" is always a no-op.
7541 height N: This integer value is the number of lines on a page. Default
7542 is 24, the current `stty rows'' setting, or the ``li#''
7543 setting from the termcap entry matching the environment
7546 width N: This integer value is the number of characters on a line.
7547 Default is 80, the current `stty cols'' setting, or the ``co#''
7548 setting from the termcap entry matching the environment
7551 Note: ``set screensize'' is obsolete. Use ``set height'' and
7552 ``set width'' instead.
7554 print address on/off: Print memory addresses in various command displays,
7555 such as stack traces and structure values. Gdb looks
7556 more ``symbolic'' if you turn this off; it looks more
7557 ``machine level'' with it on. Default is ON.
7559 print array on/off: Prettyprint arrays. New convenient format! Default
7562 print demangle on/off: Print C++ symbols in "source" form if on,
7565 print asm-demangle on/off: Same, for assembler level printouts
7568 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7571 * Support for Epoch Environment.
7573 The epoch environment is a version of Emacs v18 with windowing. One
7574 new command, ``inspect'', is identical to ``print'', except that if you
7575 are running in the epoch environment, the value is printed in its own
7579 * Support for Shared Libraries
7581 GDB can now debug programs and core files that use SunOS shared libraries.
7582 Symbols from a shared library cannot be referenced
7583 before the shared library has been linked with the program (this
7584 happens after you type ``run'' and before the function main() is entered).
7585 At any time after this linking (including when examining core files
7586 from dynamically linked programs), gdb reads the symbols from each
7587 shared library when you type the ``sharedlibrary'' command.
7588 It can be abbreviated ``share''.
7590 sharedlibrary REGEXP: Load shared object library symbols for files
7591 matching a unix regular expression. No argument
7592 indicates to load symbols for all shared libraries.
7594 info sharedlibrary: Status of loaded shared libraries.
7599 A watchpoint stops execution of a program whenever the value of an
7600 expression changes. Checking for this slows down execution
7601 tremendously whenever you are in the scope of the expression, but is
7602 quite useful for catching tough ``bit-spreader'' or pointer misuse
7603 problems. Some machines such as the 386 have hardware for doing this
7604 more quickly, and future versions of gdb will use this hardware.
7606 watch EXP: Set a watchpoint (breakpoint) for an expression.
7608 info watchpoints: Information about your watchpoints.
7610 delete N: Deletes watchpoint number N (same as breakpoints).
7611 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7612 enable N: Re-enables watchpoint number N (same as breakpoints).
7615 * C++ multiple inheritance
7617 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7620 * C++ exception handling
7622 Gdb now supports limited C++ exception handling. Besides the existing
7623 ability to breakpoint on an exception handler, gdb can breakpoint on
7624 the raising of an exception (before the stack is peeled back to the
7627 catch FOO: If there is a FOO exception handler in the dynamic scope,
7628 set a breakpoint to catch exceptions which may be raised there.
7629 Multiple exceptions (``catch foo bar baz'') may be caught.
7631 info catch: Lists all exceptions which may be caught in the
7632 current stack frame.
7635 * Minor command changes
7637 The command ``call func (arg, arg, ...)'' now acts like the print
7638 command, except it does not print or save a value if the function's result
7639 is void. This is similar to dbx usage.
7641 The ``up'' and ``down'' commands now always print the frame they end up
7642 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7643 frames without printing.
7645 * New directory command
7647 'dir' now adds directories to the FRONT of the source search path.
7648 The path starts off empty. Source files that contain debug information
7649 about the directory in which they were compiled can be found even
7650 with an empty path; Sun CC and GCC include this information. If GDB can't
7651 find your source file in the current directory, type "dir .".
7653 * Configuring GDB for compilation
7655 For normal use, type ``./configure host''. See README or gdb.texinfo
7658 GDB now handles cross debugging. If you are remotely debugging between
7659 two different machines, type ``./configure host -target=targ''.
7660 Host is the machine where GDB will run; targ is the machine
7661 where the program that you are debugging will run.