1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.3
6 * 'thread-exited' event is now available in the annotations interface.
8 * New built-in convenience variables $_gdb_major and $_gdb_minor
9 provide the GDB version. They are handy for conditionally using
10 features available only in or since specific GDB versions, in
11 scripts that should work error-free with many different versions,
12 such as in system-wide init files.
14 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
15 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
16 of the GDB settings and the GDB maintenance settings. They are handy
17 for changing the logic of user defined commands depending on the
20 * GDB now supports Thread Local Storage (TLS) variables on several
21 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
22 architectures require kernel changes. TLS is not yet supported for
23 amd64 and i386 process core dumps.
25 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
26 addresses that required unmasking are shown in the backtrace with the
29 * Two new convenience functions $_cimag and $_creal that extract the
30 imaginary and real parts respectively from complex numbers.
32 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
33 provide the exitcode or exit status of the shell commands launched by
34 GDB commands such as "shell", "pipe" and "make".
36 * The RX port now supports XML target descriptions.
38 * GDB now shows the Ada task names at more places, e.g. in task switching
41 * GDB can now be compiled with Python 3 on Windows.
43 * New convenience variable $_ada_exception holds the address of the
44 Ada exception being thrown. This is set by Ada-related catchpoints.
46 * GDB can now place breakpoints on nested functions and subroutines in
47 Fortran code. The '::' operator can be used between parent and
48 child scopes when placing breakpoints, for example:
50 (gdb) break outer_function::inner_function
52 The 'outer_function::' prefix is only needed if 'inner_function' is
53 not visible in the current scope.
55 * In addition to the system-wide gdbinit file, if configured with
56 --with-system-gdbinit-dir, GDB will now also load files in that directory
57 as system gdbinit files, unless the -nx or -n flag is provided. Files
58 with extensions .gdb, .py and .scm are supported as long as GDB was
59 compiled with support for that language.
63 ** The gdb.Value type has a new method 'format_string' which returns a
64 string representing the value. The formatting is controlled by the
65 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
66 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
67 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
69 ** gdb.Type has a new property 'objfile' which returns the objfile the
72 ** The frame information printed by the python frame filtering code
73 is now consistent with what the 'backtrace' command prints when
74 there are no filters, or when the 'backtrace' '-no-filters' option
77 ** The new function gdb.lookup_static_symbol can be used to look up
78 symbols with static linkage.
80 ** gdb.Objfile has new methods 'lookup_global_symbol' and
81 'lookup_static_symbol' to lookup a symbol from this objfile only.
83 ** gdb.Block now supports the dictionary syntax for accessing symbols in
84 this block (e.g. block['local_variable']).
88 | [COMMAND] | SHELL_COMMAND
89 | -d DELIM COMMAND DELIM SHELL_COMMAND
90 pipe [COMMAND] | SHELL_COMMAND
91 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
92 Executes COMMAND and sends its output to SHELL_COMMAND.
93 With no COMMAND, repeat the last executed command
94 and send its output to SHELL_COMMAND.
96 with SETTING [VALUE] [-- COMMAND]
97 w SETTING [VALUE] [-- COMMAND]
98 Temporarily set SETTING, run COMMAND, and restore SETTING.
99 Usage: with SETTING -- COMMAND
100 With no COMMAND, repeats the last executed command.
101 SETTING is any GDB setting you can change with the "set"
102 subcommands. For example, 'with language c -- print someobj'
103 temporarily switches to the C language in order to print someobj.
104 Settings can be combined: 'w lang c -- w print elements unlimited --
105 usercmd' switches to the C language and runs usercmd with no limit
106 of array elements to print.
108 maint with SETTING [VALUE] [-- COMMAND]
109 Like "with", but works with "maintenance set" settings.
111 set may-call-functions [on|off]
112 show may-call-functions
113 This controls whether GDB will attempt to call functions in
114 the program, such as with expressions in the print command. It
115 defaults to on. Calling functions in the program being debugged
116 can have undesired side effects. It is now possible to forbid
117 such function calls. If function calls are forbidden, GDB will throw
118 an error when a command (such as print expression) calls a function
121 set print finish [on|off]
123 This controls whether the `finish' command will display the value
124 that is returned by the current function. When `off', the value is
125 still entered into the value history, but it is not printed. The
130 Allows deeply nested structures to be simplified when printing by
131 replacing deeply nested parts (beyond the max-depth) with ellipses.
132 The default max-depth is 20, but this can be set to unlimited to get
133 the old behavior back.
135 set logging debugredirect [on|off]
136 By default, GDB debug output will go to both the terminal and the logfile.
137 Set if you want debug output to go only to the log file.
139 set style title foreground COLOR
140 set style title background COLOR
141 set style title intensity VALUE
142 Control the styling of titles.
144 set style highlight foreground COLOR
145 set style highlight background COLOR
146 set style highlight intensity VALUE
147 Control the styling of highlightings.
149 maint set test-settings KIND
150 maint show test-settings KIND
151 A set of commands used by the testsuite for exercising the settings
154 set print frame-info [short-location|location|location-and-address
155 |source-and-location|source-line|auto]
156 show print frame-info
157 This controls what frame information is printed by the commands printing
158 a frame. This setting will e.g. influence the behaviour of 'backtrace',
159 'frame', 'stepi'. The python frame filtering also respect this setting.
160 The 'backtrace' '-frame-info' option can override this global setting.
165 The "help" command uses the title style to enhance the
166 readibility of its output by styling the classes and
170 Similarly to "help", the "apropos" command also uses the
171 title style for the command names. "apropos" accepts now
172 a flag "-v" (verbose) to show the full documentation
173 of matching commands and to use the highlight style to mark
174 the documentation parts matching REGEXP.
178 The GDB printf and eval commands can now print C-style and Ada-style
179 string convenience variables without calling functions in the program.
180 This allows to do formatted printing of strings without having
181 a running inferior, or when debugging a core dump.
183 info sources [-dirname | -basename] [--] [REGEXP]
184 This command has now optional arguments to only print the files
185 whose names match REGEXP. The arguments -dirname and -basename
186 allow to restrict matching respectively to the dirname and basename
190 The "show style" and its subcommands are now styling
191 a style name in their output using its own style, to help
192 the user visualize the different styles.
194 set print frame-arguments
195 The new value 'presence' indicates to only indicate the presence of
196 arguments using ..., instead of printing argument names and values.
198 set print raw-frame-arguments
199 show print raw-frame-arguments
201 These commands replace the similarly-named "set/show print raw
202 frame-arguments" commands (now with a dash instead of a space). The
203 old commands are now deprecated and may be removed in a future
206 maint test-options require-delimiter
207 maint test-options unknown-is-error
208 maint test-options unknown-is-operand
209 maint show test-options-completion-result
210 Commands used by the testsuite to validate the command options
213 focus, winheight, +, -, >, <
214 These commands are now case-sensitive.
216 * New command options, command completion
218 GDB now has a standard infrastructure to support dash-style command
219 options ('-OPT'). One benefit is that commands that use it can
220 easily support completion of command line arguments. Try "CMD
221 -[TAB]" or "help CMD" to find options supported by a command. Over
222 time, we intend to migrate most commands to this infrastructure. A
223 number of commands got support for new command options in this
226 ** The "print" and "compile print" commands now support a number of
227 options that allow overriding relevant global print settings as
228 set by "set print" subcommands:
232 -array-indexes [on|off]
233 -elements NUMBER|unlimited
237 -repeats NUMBER|unlimited
238 -static-members [on|off]
243 Note that because the "print"/"compile print" commands accept
244 arbitrary expressions which may look like options (including
245 abbreviations), if you specify any command option, then you must
246 use a double dash ("--") to mark the end of argument processing.
248 ** The "backtrace" command now supports a number of options that
249 allow overriding relevant global print settings as set by "set
250 backtrace" and "set print" subcommands:
252 -entry-values no|only|preferred|if-needed|both|compact|default
253 -frame-arguments all|scalars|none
254 -raw-frame-arguments [on|off]
255 -frame-info auto|source-line|location|source-and-location
256 |location-and-address|short-location
260 In addition, the full/no-filters/hide qualifiers are now also
261 exposed as command options too:
267 ** The "frame apply", "tfaas" and "faas" commands similarly now
268 support the following options:
273 ** The new "info sources" options -dirname and -basename options
274 are using the standard '-OPT' infrastructure.
276 All options above can also be abbreviated. The argument of boolean
277 (on/off) options can be 0/1 too, and also the argument is assumed
278 "on" if omitted. This allows writing compact command invocations,
281 (gdb) p -r -p -o 0 -- *myptr
283 The above is equivalent to:
285 (gdb) print -raw -pretty -object off -- *myptr
287 ** The "info types" command now supports the '-q' flag to disable
288 printing of some header information in a similar fashion to "info
289 variables" and "info functions".
291 ** The "info variables", "info functions", and "whereis" commands
292 now take a '-n' flag that excludes non-debug symbols (symbols
293 from the symbol table, not from the debug info such as DWARF)
296 * Completion improvements
298 ** GDB can now complete the options of the "thread apply all" and
299 "taas" commands, and their "-ascending" option can now be
302 ** GDB can now complete the options of the "info threads", "info
303 functions", "info variables", "info locals", and "info args"
306 ** GDB can now complete the options of the "compile file" and
307 "compile code" commands. The "compile file" command now
308 completes on filenames.
310 ** GDB can now complete the backtrace command's
311 "full/no-filters/hide" qualifiers.
313 * In settings, you can now abbreviate "unlimited".
315 E.g., "set print elements u" is now equivalent to "set print
321 This lists all the possible completions for the rest of the line, if it
322 were to be given as a command itself. This is intended for use by MI
323 frontends in cases when separate CLI and MI channels cannot be used.
325 -catch-throw, -catch-rethrow, and -catch-catch
326 These can be used to catch C++ exceptions in a similar fashion to
327 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
331 ** The default version of the MI interpreter is now 3 (-i=mi3).
333 ** The output of information about multi-location breakpoints (which is
334 syntactically incorrect in MI 2) has changed in MI 3. This affects
335 the following commands and events:
339 - =breakpoint-created
340 - =breakpoint-modified
342 The -fix-multi-location-breakpoint-output command can be used to enable
343 this behavior with previous MI versions.
345 ** Backtraces and frames include a new optional field addr_flags which is
346 given after the addr field. On AArch64 this contains PAC if the address
347 has been masked in the frame. On all other targets the field is not
352 The testsuite now creates the files gdb.cmd (containing the arguments
353 used to launch GDB) and gdb.in (containing all the commands sent to
354 GDB) in the output directory for each test script. Multiple invocations
355 are appended with .1, .2, .3 etc.
357 * Building GDB and GDBserver now requires GNU make >= 3.82.
359 Using another implementation of the make program or an earlier version of
360 GNU make to build GDB or GDBserver is not supported.
362 * Building GDB now requires GNU readline >= 7.0.
364 GDB now bundles GNU readline 8.0, but if you choose to use
365 --with-system-readline, only readline >= 7.0 can be used.
367 * The TUI SingleKey keymap is now named "SingleKey". This can be used
368 from .inputrc to bind keys in this keymap. This feature is only
369 available when gdb is built against GNU readline 8.0 or later.
371 * Removed targets and native configurations
373 GDB no longer supports debugging the Cell Broadband Engine. This includes
374 both debugging standalone Cell/B.E. SPU applications and integrated debugging
375 of Cell/B.E. applications that use both the PPU and SPU architectures.
381 *** Changes in GDB 8.3
383 * GDB and GDBserver now support access to additional registers on
384 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
387 * GDB now has experimental support for the compilation and injection of
388 C++ source code into the inferior. This beta release does not include
389 support for several language features, such as templates, constructors,
392 This feature requires GCC 7.1 or higher built with libcp1.so
395 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
396 can be passed using the '[ADDRESS]:PORT' notation, or the regular
397 'ADDRESS:PORT' method.
399 * DWARF index cache: GDB can now automatically save indices of DWARF
400 symbols on disk to speed up further loading of the same binaries.
402 * Ada task switching is now supported on aarch64-elf targets when
403 debugging a program using the Ravenscar Profile. For more information,
404 see the "Tasking Support when using the Ravenscar Profile" section
405 in the GDB user manual.
407 * GDB in batch mode now exits with status 1 if the last command to be
410 * The RISC-V target now supports target descriptions.
412 * System call catchpoints now support system call aliases on FreeBSD.
413 When the ABI of a system call changes in FreeBSD, this is
414 implemented by leaving a compatibility system call using the old ABI
415 at the existing number and allocating a new system call number for
416 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
417 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
418 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
419 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
420 so that a system call catchpoint for the 'kevent' system call will
421 catch invocations of both the 'kevent' and 'freebsd11_kevent'
422 binaries. This ensures that 'kevent' system calls are caught for
423 binaries using either the old or new ABIs.
425 * Terminal styling is now available for the CLI and the TUI. GNU
426 Source Highlight can additionally be used to provide styling of
427 source code snippets. See the "set style" commands, below, for more
430 * Removed support for old demangling styles arm, edg, gnu, hp and
435 set debug compile-cplus-types
436 show debug compile-cplus-types
437 Control the display of debug output about type conversion in the
438 C++ compile feature. Commands have no effect while compiliong
443 Control whether debug output about files/functions skipping is
446 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
447 Apply a command to some frames.
448 FLAG arguments allow to control what output to produce and how to handle
449 errors raised when applying COMMAND to a frame.
452 Apply a command to all threads (ignoring errors and empty output).
453 Shortcut for 'thread apply all -s COMMAND'.
456 Apply a command to all frames (ignoring errors and empty output).
457 Shortcut for 'frame apply all -s COMMAND'.
460 Apply a command to all frames of all threads (ignoring errors and empty
462 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
464 maint set dwarf unwinders (on|off)
465 maint show dwarf unwinders
466 Control whether DWARF unwinders can be used.
469 Display a list of open files for a process.
473 Changes to the "frame", "select-frame", and "info frame" CLI commands.
474 These commands all now take a frame specification which
475 is either a frame level, or one of the keywords 'level', 'address',
476 'function', or 'view' followed by a parameter. Selecting a frame by
477 address, or viewing a frame outside the current backtrace now
478 requires the use of a keyword. Selecting a frame by level is
479 unchanged. The MI comment "-stack-select-frame" is unchanged.
481 target remote FILENAME
482 target extended-remote FILENAME
483 If FILENAME is a Unix domain socket, GDB will attempt to connect
484 to this socket instead of opening FILENAME as a character device.
486 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
487 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
488 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
489 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
490 These commands can now print only the searched entities
491 matching the provided regexp(s), giving a condition
492 on the entity names or entity types. The flag -q disables
493 printing headers or informations messages.
499 These commands now determine the syntax for the shown entities
500 according to the language chosen by `set language'. In particular,
501 `set language auto' means to automatically choose the language of
504 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
505 The 'thread apply' command accepts new FLAG arguments.
506 FLAG arguments allow to control what output to produce and how to handle
507 errors raised when applying COMMAND to a thread.
509 set tui tab-width NCHARS
510 show tui tab-width NCHARS
511 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
513 set style enabled [on|off]
515 Enable or disable terminal styling. Styling is enabled by default
516 on most hosts, but disabled by default when in batch mode.
518 set style sources [on|off]
520 Enable or disable source code styling. Source code styling is
521 enabled by default, but only takes effect if styling in general is
522 enabled, and if GDB was linked with GNU Source Highlight.
524 set style filename foreground COLOR
525 set style filename background COLOR
526 set style filename intensity VALUE
527 Control the styling of file names.
529 set style function foreground COLOR
530 set style function background COLOR
531 set style function intensity VALUE
532 Control the styling of function names.
534 set style variable foreground COLOR
535 set style variable background COLOR
536 set style variable intensity VALUE
537 Control the styling of variable names.
539 set style address foreground COLOR
540 set style address background COLOR
541 set style address intensity VALUE
542 Control the styling of addresses.
546 ** The '-data-disassemble' MI command now accepts an '-a' option to
547 disassemble the whole function surrounding the given program
548 counter value or function name. Support for this feature can be
549 verified by using the "-list-features" command, which should
550 contain "data-disassemble-a-option".
552 ** Command responses and notifications that include a frame now include
553 the frame's architecture in a new "arch" attribute.
555 * New native configurations
557 GNU/Linux/RISC-V riscv*-*-linux*
558 FreeBSD/riscv riscv*-*-freebsd*
562 GNU/Linux/RISC-V riscv*-*-linux*
564 CSKY GNU/LINUX csky*-*-linux
565 FreeBSD/riscv riscv*-*-freebsd*
567 GNU/Linux/OpenRISC or1k*-*-linux*
571 GDB no longer supports native debugging on versions of MS-Windows
576 ** GDB no longer supports Python versions less than 2.6.
578 ** The gdb.Inferior type has a new 'progspace' property, which is the program
579 space associated to that inferior.
581 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
582 of objfiles associated to that program space.
584 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
585 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
588 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
589 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
590 correct and did not work properly.
592 ** The gdb.Value type has a new constructor, which is used to construct a
593 gdb.Value from a Python buffer object and a gdb.Type.
599 Enable or disable the undefined behavior sanitizer. This is
600 disabled by default, but passing --enable-ubsan=yes or
601 --enable-ubsan=auto to configure will enable it. Enabling this can
602 cause a performance penalty. The undefined behavior sanitizer was
603 first introduced in GCC 4.9.
605 *** Changes in GDB 8.2
607 * The 'set disassembler-options' command now supports specifying options
610 * The 'symbol-file' command now accepts an '-o' option to add a relative
611 offset to all sections.
613 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
614 a relative offset to all sections, but it allows to override the load
615 address of individual sections using '-s'.
617 * The 'add-symbol-file' command no longer requires the second argument
618 (address of the text section).
620 * The endianness used with the 'set endian auto' mode in the absence of
621 an executable selected for debugging is now the last endianness chosen
622 either by one of the 'set endian big' and 'set endian little' commands
623 or by inferring from the last executable used, rather than the startup
626 * The pager now allows a "c" response, meaning to disable the pager
627 for the rest of the current command.
629 * The commands 'info variables/functions/types' now show the source line
630 numbers of symbol definitions when available.
632 * 'info proc' now works on running processes on FreeBSD systems and core
633 files created on FreeBSD systems.
635 * C expressions can now use _Alignof, and C++ expressions can now use
638 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
639 the vector length while the process is running.
645 Control display of debugging info regarding the FreeBSD native target.
647 set|show varsize-limit
648 This new setting allows the user to control the maximum size of Ada
649 objects being printed when those objects have a variable type,
650 instead of that maximum size being hardcoded to 65536 bytes.
652 set|show record btrace cpu
653 Controls the processor to be used for enabling errata workarounds for
656 maint check libthread-db
657 Run integrity checks on the current inferior's thread debugging
660 maint set check-libthread-db (on|off)
661 maint show check-libthread-db
662 Control whether to run integrity checks on inferior specific thread
663 debugging libraries as they are loaded. The default is not to
668 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
670 ** The commands attached to a breakpoint can be set by assigning to
671 the breakpoint's "commands" field.
673 ** gdb.execute can now execute multi-line gdb commands.
675 ** The new functions gdb.convenience_variable and
676 gdb.set_convenience_variable can be used to get and set the value
677 of convenience variables.
679 ** A gdb.Parameter will no longer print the "set" help text on an
680 ordinary "set"; instead by default a "set" will be silent unless
681 the get_set_string method returns a non-empty string.
685 RiscV ELF riscv*-*-elf
687 * Removed targets and native configurations
689 m88k running OpenBSD m88*-*-openbsd*
690 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
691 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
692 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
694 * Aarch64/Linux hardware watchpoints improvements
696 Hardware watchpoints on unaligned addresses are now properly
697 supported when running Linux kernel 4.10 or higher: read and access
698 watchpoints are no longer spuriously missed, and all watchpoints
699 lengths between 1 and 8 bytes are supported. On older kernels,
700 watchpoints set on unaligned addresses are no longer missed, with
701 the tradeoff that there is a possibility of false hits being
706 --enable-codesign=CERT
707 This can be used to invoke "codesign -s CERT" after building gdb.
708 This option is useful on macOS, where code signing is required for
709 gdb to work properly.
711 --disable-gdbcli has been removed
712 This is now silently accepted, but does nothing.
714 *** Changes in GDB 8.1
716 * GDB now supports dynamically creating arbitrary register groups specified
717 in XML target descriptions. This allows for finer grain grouping of
718 registers on systems with a large amount of registers.
720 * The 'ptype' command now accepts a '/o' flag, which prints the
721 offsets and sizes of fields in a struct, like the pahole(1) tool.
723 * New "--readnever" command line option instructs GDB to not read each
724 symbol file's symbolic debug information. This makes startup faster
725 but at the expense of not being able to perform symbolic debugging.
726 This option is intended for use cases where symbolic debugging will
727 not be used, e.g., when you only need to dump the debuggee's core.
729 * GDB now uses the GNU MPFR library, if available, to emulate target
730 floating-point arithmetic during expression evaluation when the target
731 uses different floating-point formats than the host. At least version
732 3.1 of GNU MPFR is required.
734 * GDB now supports access to the guarded-storage-control registers and the
735 software-based guarded-storage broadcast control registers on IBM z14.
737 * On Unix systems, GDB now supports transmitting environment variables
738 that are to be set or unset to GDBserver. These variables will
739 affect the environment to be passed to the remote inferior.
741 To inform GDB of environment variables that are to be transmitted to
742 GDBserver, use the "set environment" command. Only user set
743 environment variables are sent to GDBserver.
745 To inform GDB of environment variables that are to be unset before
746 the remote inferior is started by the GDBserver, use the "unset
747 environment" command.
749 * Completion improvements
751 ** GDB can now complete function parameters in linespecs and
752 explicit locations without quoting. When setting breakpoints,
753 quoting around functions names to help with TAB-completion is
754 generally no longer necessary. For example, this now completes
757 (gdb) b function(in[TAB]
758 (gdb) b function(int)
760 Related, GDB is no longer confused with completing functions in
761 C++ anonymous namespaces:
764 (gdb) b (anonymous namespace)::[TAB][TAB]
765 (anonymous namespace)::a_function()
766 (anonymous namespace)::b_function()
768 ** GDB now has much improved linespec and explicit locations TAB
769 completion support, that better understands what you're
770 completing and offers better suggestions. For example, GDB no
771 longer offers data symbols as possible completions when you're
772 setting a breakpoint.
774 ** GDB now TAB-completes label symbol names.
776 ** The "complete" command now mimics TAB completion accurately.
778 * New command line options (gcore)
781 Dump all memory mappings.
783 * Breakpoints on C++ functions are now set on all scopes by default
785 By default, breakpoints on functions/methods are now interpreted as
786 specifying all functions with the given name ignoring missing
787 leading scopes (namespaces and classes).
789 For example, assuming a C++ program with symbols named:
794 both commands "break func()" and "break B::func()" set a breakpoint
797 You can use the new flag "-qualified" to override this. This makes
798 GDB interpret the specified function name as a complete
799 fully-qualified name instead. For example, using the same C++
800 program, the "break -q B::func" command sets a breakpoint on
801 "B::func", only. A parameter has been added to the Python
802 gdb.Breakpoint constructor to achieve the same result when creating
803 a breakpoint from Python.
805 * Breakpoints on functions marked with C++ ABI tags
807 GDB can now set breakpoints on functions marked with C++ ABI tags
808 (e.g., [abi:cxx11]). See here for a description of ABI tags:
809 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
811 Functions with a C++11 abi tag are demangled/displayed like this:
813 function[abi:cxx11](int)
816 You can now set a breakpoint on such functions simply as if they had
819 (gdb) b function(int)
821 Or if you need to disambiguate between tags, like:
823 (gdb) b function[abi:other_tag](int)
825 Tab completion was adjusted accordingly as well.
829 ** New events gdb.new_inferior, gdb.inferior_deleted, and
830 gdb.new_thread are emitted. See the manual for further
831 description of these.
833 ** A new function, "gdb.rbreak" has been added to the Python API.
834 This function allows the setting of a large number of breakpoints
835 via a regex pattern in Python. See the manual for further details.
837 ** Python breakpoints can now accept explicit locations. See the
838 manual for a further description of this feature.
841 * New features in the GDB remote stub, GDBserver
843 ** GDBserver is now able to start inferior processes with a
844 specified initial working directory.
846 The user can set the desired working directory to be used from
847 GDB using the new "set cwd" command.
849 ** New "--selftest" command line option runs some GDBserver self
850 tests. These self tests are disabled in releases.
852 ** On Unix systems, GDBserver now does globbing expansion and variable
853 substitution in inferior command line arguments.
855 This is done by starting inferiors using a shell, like GDB does.
856 See "set startup-with-shell" in the user manual for how to disable
857 this from GDB when using "target extended-remote". When using
858 "target remote", you can disable the startup with shell by using the
859 new "--no-startup-with-shell" GDBserver command line option.
861 ** On Unix systems, GDBserver now supports receiving environment
862 variables that are to be set or unset from GDB. These variables
863 will affect the environment to be passed to the inferior.
865 * When catching an Ada exception raised with a message, GDB now prints
866 the message in the catchpoint hit notification. In GDB/MI mode, that
867 information is provided as an extra field named "exception-message"
868 in the *stopped notification.
870 * Trait objects can now be inspected When debugging Rust code. This
871 requires compiler support which will appear in Rust 1.24.
875 QEnvironmentHexEncoded
876 Inform GDBserver of an environment variable that is to be passed to
877 the inferior when starting it.
880 Inform GDBserver of an environment variable that is to be unset
881 before starting the remote inferior.
884 Inform GDBserver that the environment should be reset (i.e.,
885 user-set environment variables should be unset).
888 Indicates whether the inferior must be started with a shell or not.
891 Tell GDBserver that the inferior to be started should use a specific
894 * The "maintenance print c-tdesc" command now takes an optional
895 argument which is the file name of XML target description.
897 * The "maintenance selftest" command now takes an optional argument to
898 filter the tests to be run.
900 * The "enable", and "disable" commands now accept a range of
901 breakpoint locations, e.g. "enable 1.3-5".
906 Set and show the current working directory for the inferior.
909 Set and show compilation command used for compiling and injecting code
910 with the 'compile' commands.
912 set debug separate-debug-file
913 show debug separate-debug-file
914 Control the display of debug output about separate debug file search.
916 set dump-excluded-mappings
917 show dump-excluded-mappings
918 Control whether mappings marked with the VM_DONTDUMP flag should be
919 dumped when generating a core file.
922 List the registered selftests.
925 Start the debugged program stopping at the first instruction.
928 Control display of debugging messages related to OpenRISC targets.
930 set|show print type nested-type-limit
931 Set and show the limit of nesting level for nested types that the
932 type printer will show.
934 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
937 * Safer/improved support for debugging with no debug info
939 GDB no longer assumes functions with no debug information return
942 This means that GDB now refuses to call such functions unless you
943 tell it the function's type, by either casting the call to the
944 declared return type, or by casting the function to a function
945 pointer of the right type, and calling that:
947 (gdb) p getenv ("PATH")
948 'getenv' has unknown return type; cast the call to its declared return type
949 (gdb) p (char *) getenv ("PATH")
950 $1 = 0x7fffffffe "/usr/local/bin:/"...
951 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
952 $2 = 0x7fffffffe "/usr/local/bin:/"...
954 Similarly, GDB no longer assumes that global variables with no debug
955 info have type 'int', and refuses to print the variable's value
956 unless you tell it the variable's type:
959 'var' has unknown type; cast it to its declared type
963 * New native configurations
965 FreeBSD/aarch64 aarch64*-*-freebsd*
966 FreeBSD/arm arm*-*-freebsd*
970 FreeBSD/aarch64 aarch64*-*-freebsd*
971 FreeBSD/arm arm*-*-freebsd*
972 OpenRISC ELF or1k*-*-elf
974 * Removed targets and native configurations
976 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
978 *** Changes in GDB 8.0
980 * GDB now supports access to the PKU register on GNU/Linux. The register is
981 added by the Memory Protection Keys for Userspace feature which will be
982 available in future Intel CPUs.
984 * GDB now supports C++11 rvalue references.
988 ** New functions to start, stop and access a running btrace recording.
989 ** Rvalue references are now supported in gdb.Type.
991 * GDB now supports recording and replaying rdrand and rdseed Intel 64
994 * Building GDB and GDBserver now requires a C++11 compiler.
996 For example, GCC 4.8 or later.
998 It is no longer possible to build GDB or GDBserver with a C
999 compiler. The --disable-build-with-cxx configure option has been
1002 * Building GDB and GDBserver now requires GNU make >= 3.81.
1004 It is no longer supported to build GDB or GDBserver with another
1005 implementation of the make program or an earlier version of GNU make.
1007 * Native debugging on MS-Windows supports command-line redirection
1009 Command-line arguments used for starting programs on MS-Windows can
1010 now include redirection symbols supported by native Windows shells,
1011 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1012 as "run", "start", and "set args", as well as the corresponding MI
1015 * Support for thread names on MS-Windows.
1017 GDB now catches and handles the special exception that programs
1018 running on MS-Windows use to assign names to threads in the
1021 * Support for Java programs compiled with gcj has been removed.
1023 * User commands now accept an unlimited number of arguments.
1024 Previously, only up to 10 was accepted.
1026 * The "eval" command now expands user-defined command arguments.
1028 This makes it easier to process a variable number of arguments:
1033 eval "print $arg%d", $i
1038 * Target descriptions can now describe registers for sparc32 and sparc64.
1040 * GDB now supports DWARF version 5 (debug information format).
1041 Its .debug_names index is not yet supported.
1043 * New native configurations
1045 FreeBSD/mips mips*-*-freebsd
1049 Synopsys ARC arc*-*-elf32
1050 FreeBSD/mips mips*-*-freebsd
1052 * Removed targets and native configurations
1054 Alpha running FreeBSD alpha*-*-freebsd*
1055 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1060 Erases all the flash memory regions reported by the target.
1062 maint print arc arc-instruction address
1063 Print internal disassembler information about instruction at a given address.
1067 set disassembler-options
1068 show disassembler-options
1069 Controls the passing of target specific information to the disassembler.
1070 If it is necessary to specify more than one disassembler option then
1071 multiple options can be placed together into a comma separated list.
1072 The default value is the empty string. Currently, the only supported
1073 targets are ARM, PowerPC and S/390.
1078 Erases all the flash memory regions reported by the target. This is
1079 equivalent to the CLI command flash-erase.
1081 -file-list-shared-libraries
1082 List the shared libraries in the program. This is
1083 equivalent to the CLI command "info shared".
1086 Catchpoints stopping the program when Ada exceptions are
1087 handled. This is equivalent to the CLI command "catch handlers".
1089 *** Changes in GDB 7.12
1091 * GDB and GDBserver now build with a C++ compiler by default.
1093 The --enable-build-with-cxx configure option is now enabled by
1094 default. One must now explicitly configure with
1095 --disable-build-with-cxx in order to build with a C compiler. This
1096 option will be removed in a future release.
1098 * GDBserver now supports recording btrace without maintaining an active
1101 * GDB now supports a negative repeat count in the 'x' command to examine
1102 memory backward from the given address. For example:
1105 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1106 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1107 (gdb) x/-5i 0x0000000000400580
1108 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1109 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1110 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1111 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1112 0x40057b <main(int, char**)+25>:
1113 callq 0x400536 <Func1(int, char const*)>
1115 * Fortran: Support structures with fields of dynamic types and
1116 arrays of dynamic types.
1118 * The symbol dumping maintenance commands have new syntax.
1119 maint print symbols [-pc address] [--] [filename]
1120 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1121 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1122 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1123 maint print msymbols [-objfile objfile] [--] [filename]
1125 * GDB now supports multibit bitfields and enums in target register
1128 * New Python-based convenience function $_as_string(val), which returns
1129 the textual representation of a value. This function is especially
1130 useful to obtain the text label of an enum value.
1132 * Intel MPX bound violation handling.
1134 Segmentation faults caused by a Intel MPX boundary violation
1135 now display the kind of violation (upper or lower), the memory
1136 address accessed and the memory bounds, along with the usual
1137 signal received and code location.
1141 Program received signal SIGSEGV, Segmentation fault
1142 Upper bound violation while accessing address 0x7fffffffc3b3
1143 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1144 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1146 * Rust language support.
1147 GDB now supports debugging programs written in the Rust programming
1148 language. See https://www.rust-lang.org/ for more information about
1151 * Support for running interpreters on specified input/output devices
1153 GDB now supports a new mechanism that allows frontends to provide
1154 fully featured GDB console views, as a better alternative to
1155 building such views on top of the "-interpreter-exec console"
1156 command. See the new "new-ui" command below. With that command,
1157 frontends can now start GDB in the traditional command-line mode
1158 running in an embedded terminal emulator widget, and create a
1159 separate MI interpreter running on a specified i/o device. In this
1160 way, GDB handles line editing, history, tab completion, etc. in the
1161 console all by itself, and the GUI uses the separate MI interpreter
1162 for its own control and synchronization, invisible to the command
1165 * The "catch syscall" command catches groups of related syscalls.
1167 The "catch syscall" command now supports catching a group of related
1168 syscalls using the 'group:' or 'g:' prefix.
1173 skip -gfile file-glob-pattern
1174 skip -function function
1175 skip -rfunction regular-expression
1176 A generalized form of the skip command, with new support for
1177 glob-style file names and regular expressions for function names.
1178 Additionally, a file spec and a function spec may now be combined.
1180 maint info line-table REGEXP
1181 Display the contents of GDB's internal line table data struture.
1184 Run any GDB unit tests that were compiled in.
1187 Start a new user interface instance running INTERP as interpreter,
1188 using the TTY file for input/output.
1192 ** gdb.Breakpoint objects have a new attribute "pending", which
1193 indicates whether the breakpoint is pending.
1194 ** Three new breakpoint-related events have been added:
1195 gdb.breakpoint_created, gdb.breakpoint_modified, and
1196 gdb.breakpoint_deleted.
1198 signal-event EVENTID
1199 Signal ("set") the given MS-Windows event object. This is used in
1200 conjunction with the Windows JIT debugging (AeDebug) support, where
1201 the OS suspends a crashing process until a debugger can attach to
1202 it. Resuming the crashing process, in order to debug it, is done by
1203 signalling an event.
1205 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1206 was added in GDBserver, including JIT compiling fast tracepoint's
1207 conditional expression bytecode into native code.
1209 * Support for various remote target protocols and ROM monitors has
1212 target m32rsdi Remote M32R debugging over SDI
1213 target mips MIPS remote debugging protocol
1214 target pmon PMON ROM monitor
1215 target ddb NEC's DDB variant of PMON for Vr4300
1216 target rockhopper NEC RockHopper variant of PMON
1217 target lsi LSI variant of PMO
1219 * Support for tracepoints and fast tracepoints on powerpc-linux,
1220 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1221 including JIT compiling fast tracepoint's conditional expression
1222 bytecode into native code.
1224 * MI async record =record-started now includes the method and format used for
1225 recording. For example:
1227 =record-started,thread-group="i1",method="btrace",format="bts"
1229 * MI async record =thread-selected now includes the frame field. For example:
1231 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1235 Andes NDS32 nds32*-*-elf
1237 *** Changes in GDB 7.11
1239 * GDB now supports debugging kernel-based threads on FreeBSD.
1241 * Per-inferior thread numbers
1243 Thread numbers are now per inferior instead of global. If you're
1244 debugging multiple inferiors, GDB displays thread IDs using a
1245 qualified INF_NUM.THR_NUM form. For example:
1249 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1250 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1251 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1252 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1254 As consequence, thread numbers as visible in the $_thread
1255 convenience variable and in Python's InferiorThread.num attribute
1256 are no longer unique between inferiors.
1258 GDB now maintains a second thread ID per thread, referred to as the
1259 global thread ID, which is the new equivalent of thread numbers in
1260 previous releases. See also $_gthread below.
1262 For backwards compatibility, MI's thread IDs always refer to global
1265 * Commands that accept thread IDs now accept the qualified
1266 INF_NUM.THR_NUM form as well. For example:
1269 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1272 * In commands that accept a list of thread IDs, you can now refer to
1273 all threads of an inferior using a star wildcard. GDB accepts
1274 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1275 refer to all threads of the current inferior. For example, "info
1278 * You can use "info threads -gid" to display the global thread ID of
1281 * The new convenience variable $_gthread holds the global number of
1284 * The new convenience variable $_inferior holds the number of the
1287 * GDB now displays the ID and name of the thread that hit a breakpoint
1288 or received a signal, if your program is multi-threaded. For
1291 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1292 Thread 1 "main" received signal SIGINT, Interrupt.
1294 * Record btrace now supports non-stop mode.
1296 * Support for tracepoints on aarch64-linux was added in GDBserver.
1298 * The 'record instruction-history' command now indicates speculative execution
1299 when using the Intel Processor Trace recording format.
1301 * GDB now allows users to specify explicit locations, bypassing
1302 the linespec parser. This feature is also available to GDB/MI
1305 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1306 GDB now is able to debug both AArch64 applications and ARM applications
1309 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1310 including JIT compiling fast tracepoint's conditional expression bytecode
1313 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1315 * "info threads", "info inferiors", "info display", "info checkpoints"
1316 and "maint info program-spaces" now list the corresponding items in
1317 ascending ID order, for consistency with all other "info" commands.
1319 * In Ada, the overloads selection menu has been enhanced to display the
1320 parameter types and the return types for the matching overloaded subprograms.
1324 maint set target-non-stop (on|off|auto)
1325 maint show target-non-stop
1326 Control whether GDB targets always operate in non-stop mode even if
1327 "set non-stop" is "off". The default is "auto", meaning non-stop
1328 mode is enabled if supported by the target.
1330 maint set bfd-sharing
1331 maint show bfd-sharing
1332 Control the reuse of bfd objects.
1335 show debug bfd-cache
1336 Control display of debugging info regarding bfd caching.
1340 Control display of debugging info regarding FreeBSD threads.
1342 set remote multiprocess-extensions-packet
1343 show remote multiprocess-extensions-packet
1344 Set/show the use of the remote protocol multiprocess extensions.
1346 set remote thread-events
1347 show remote thread-events
1348 Set/show the use of thread create/exit events.
1350 set ada print-signatures on|off
1351 show ada print-signatures"
1352 Control whether parameter types and return types are displayed in overloads
1353 selection menus. It is activaled (@code{on}) by default.
1357 Controls the maximum size of memory, in bytes, that GDB will
1358 allocate for value contents. Prevents incorrect programs from
1359 causing GDB to allocate overly large buffers. Default is 64k.
1361 * The "disassemble" command accepts a new modifier: /s.
1362 It prints mixed source+disassembly like /m with two differences:
1363 - disassembled instructions are now printed in program order, and
1364 - and source for all relevant files is now printed.
1365 The "/m" option is now considered deprecated: its "source-centric"
1366 output hasn't proved useful in practice.
1368 * The "record instruction-history" command accepts a new modifier: /s.
1369 It behaves exactly like /m and prints mixed source+disassembly.
1371 * The "set scheduler-locking" command supports a new mode "replay".
1372 It behaves like "off" in record mode and like "on" in replay mode.
1374 * Support for various ROM monitors has been removed:
1376 target dbug dBUG ROM monitor for Motorola ColdFire
1377 target picobug Motorola picobug monitor
1378 target dink32 DINK32 ROM monitor for PowerPC
1379 target m32r Renesas M32R/D ROM monitor
1380 target mon2000 mon2000 ROM monitor
1381 target ppcbug PPCBUG ROM monitor for PowerPC
1383 * Support for reading/writing memory and extracting values on architectures
1384 whose memory is addressable in units of any integral multiple of 8 bits.
1387 Allows to break when an Ada exception is handled.
1389 * New remote packets
1392 Indicates that an exec system call was executed.
1394 exec-events feature in qSupported
1395 The qSupported packet allows GDB to request support for exec
1396 events using the new 'gdbfeature' exec-event, and the qSupported
1397 response can contain the corresponding 'stubfeature'. Set and
1398 show commands can be used to display whether these features are enabled.
1401 Equivalent to interrupting with the ^C character, but works in
1404 thread created stop reason (T05 create:...)
1405 Indicates that the thread was just created and is stopped at entry.
1407 thread exit stop reply (w exitcode;tid)
1408 Indicates that the thread has terminated.
1411 Enables/disables thread create and exit event reporting. For
1412 example, this is used in non-stop mode when GDB stops a set of
1413 threads and synchronously waits for the their corresponding stop
1414 replies. Without exit events, if one of the threads exits, GDB
1415 would hang forever not knowing that it should no longer expect a
1416 stop for that same thread.
1419 Indicates that there are no resumed threads left in the target (all
1420 threads are stopped). The remote stub reports support for this stop
1421 reply to GDB's qSupported query.
1424 Enables/disables catching syscalls from the inferior process.
1425 The remote stub reports support for this packet to GDB's qSupported query.
1427 syscall_entry stop reason
1428 Indicates that a syscall was just called.
1430 syscall_return stop reason
1431 Indicates that a syscall just returned.
1433 * Extended-remote exec events
1435 ** GDB now has support for exec events on extended-remote Linux targets.
1436 For such targets with Linux kernels 2.5.46 and later, this enables
1437 follow-exec-mode and exec catchpoints.
1439 set remote exec-event-feature-packet
1440 show remote exec-event-feature-packet
1441 Set/show the use of the remote exec event feature.
1443 * Thread names in remote protocol
1445 The reply to qXfer:threads:read may now include a name attribute for each
1448 * Target remote mode fork and exec events
1450 ** GDB now has support for fork and exec events on target remote mode
1451 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1452 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1453 fork and exec catchpoints.
1455 * Remote syscall events
1457 ** GDB now has support for catch syscall on remote Linux targets,
1458 currently enabled on x86/x86_64 architectures.
1460 set remote catch-syscall-packet
1461 show remote catch-syscall-packet
1462 Set/show the use of the remote catch syscall feature.
1466 ** The -var-set-format command now accepts the zero-hexadecimal
1467 format. It outputs data in hexadecimal format with zero-padding on the
1472 ** gdb.InferiorThread objects have a new attribute "global_num",
1473 which refers to the thread's global thread ID. The existing
1474 "num" attribute now refers to the thread's per-inferior number.
1475 See "Per-inferior thread numbers" above.
1476 ** gdb.InferiorThread objects have a new attribute "inferior", which
1477 is the Inferior object the thread belongs to.
1479 *** Changes in GDB 7.10
1481 * Support for process record-replay and reverse debugging on aarch64*-linux*
1482 targets has been added. GDB now supports recording of A64 instruction set
1483 including advance SIMD instructions.
1485 * Support for Sun's version of the "stabs" debug file format has been removed.
1487 * GDB now honors the content of the file /proc/PID/coredump_filter
1488 (PID is the process ID) on GNU/Linux systems. This file can be used
1489 to specify the types of memory mappings that will be included in a
1490 corefile. For more information, please refer to the manual page of
1491 "core(5)". GDB also has a new command: "set use-coredump-filter
1492 on|off". It allows to set whether GDB will read the content of the
1493 /proc/PID/coredump_filter file when generating a corefile.
1495 * The "info os" command on GNU/Linux can now display information on
1497 "info os cpus" Listing of all cpus/cores on the system
1499 * GDB has two new commands: "set serial parity odd|even|none" and
1500 "show serial parity". These allows to set or show parity for the
1503 * The "info source" command now displays the producer string if it was
1504 present in the debug info. This typically includes the compiler version
1505 and may include things like its command line arguments.
1507 * The "info dll", an alias of the "info sharedlibrary" command,
1508 is now available on all platforms.
1510 * Directory names supplied to the "set sysroot" commands may be
1511 prefixed with "target:" to tell GDB to access shared libraries from
1512 the target system, be it local or remote. This replaces the prefix
1513 "remote:". The default sysroot has been changed from "" to
1514 "target:". "remote:" is automatically converted to "target:" for
1515 backward compatibility.
1517 * The system root specified by "set sysroot" will be prepended to the
1518 filename of the main executable (if reported to GDB as absolute by
1519 the operating system) when starting processes remotely, and when
1520 attaching to already-running local or remote processes.
1522 * GDB now supports automatic location and retrieval of executable
1523 files from remote targets. Remote debugging can now be initiated
1524 using only a "target remote" or "target extended-remote" command
1525 (no "set sysroot" or "file" commands are required). See "New remote
1528 * The "dump" command now supports verilog hex format.
1530 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1532 * On GNU/Linux, GDB and gdbserver are now able to access executable
1533 and shared library files without a "set sysroot" command when
1534 attaching to processes running in different mount namespaces from
1535 the debugger. This makes it possible to attach to processes in
1536 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1537 See "New remote packets" below.
1539 * The "tui reg" command now provides completion for all of the
1540 available register groups, including target specific groups.
1542 * The HISTSIZE environment variable is no longer read when determining
1543 the size of GDB's command history. GDB now instead reads the dedicated
1544 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1545 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1550 ** Memory ports can now be unbuffered.
1554 ** gdb.Objfile objects have a new attribute "username",
1555 which is the name of the objfile as specified by the user,
1556 without, for example, resolving symlinks.
1557 ** You can now write frame unwinders in Python.
1558 ** gdb.Type objects have a new method "optimized_out",
1559 returning optimized out gdb.Value instance of this type.
1560 ** gdb.Value objects have new methods "reference_value" and
1561 "const_value" which return a reference to the value and a
1562 "const" version of the value respectively.
1566 maint print symbol-cache
1567 Print the contents of the symbol cache.
1569 maint print symbol-cache-statistics
1570 Print statistics of symbol cache usage.
1572 maint flush-symbol-cache
1573 Flush the contents of the symbol cache.
1577 Start branch trace recording using Branch Trace Store (BTS) format.
1580 Evaluate expression by using the compiler and print result.
1584 Explicit commands for enabling and disabling tui mode.
1587 set mpx bound on i386 and amd64
1588 Support for bound table investigation on Intel MPX enabled applications.
1592 Start branch trace recording using Intel Processor Trace format.
1595 Print information about branch tracing internals.
1597 maint btrace packet-history
1598 Print the raw branch tracing data.
1600 maint btrace clear-packet-history
1601 Discard the stored raw branch tracing data.
1604 Discard all branch tracing data. It will be fetched and processed
1605 anew by the next "record" command.
1610 Renamed from "set debug dwarf2-die".
1611 show debug dwarf-die
1612 Renamed from "show debug dwarf2-die".
1614 set debug dwarf-read
1615 Renamed from "set debug dwarf2-read".
1616 show debug dwarf-read
1617 Renamed from "show debug dwarf2-read".
1619 maint set dwarf always-disassemble
1620 Renamed from "maint set dwarf2 always-disassemble".
1621 maint show dwarf always-disassemble
1622 Renamed from "maint show dwarf2 always-disassemble".
1624 maint set dwarf max-cache-age
1625 Renamed from "maint set dwarf2 max-cache-age".
1626 maint show dwarf max-cache-age
1627 Renamed from "maint show dwarf2 max-cache-age".
1629 set debug dwarf-line
1630 show debug dwarf-line
1631 Control display of debugging info regarding DWARF line processing.
1634 show max-completions
1635 Set the maximum number of candidates to be considered during
1636 completion. The default value is 200. This limit allows GDB
1637 to avoid generating large completion lists, the computation of
1638 which can cause the debugger to become temporarily unresponsive.
1640 set history remove-duplicates
1641 show history remove-duplicates
1642 Control the removal of duplicate history entries.
1644 maint set symbol-cache-size
1645 maint show symbol-cache-size
1646 Control the size of the symbol cache.
1648 set|show record btrace bts buffer-size
1649 Set and show the size of the ring buffer used for branch tracing in
1651 The obtained size may differ from the requested size. Use "info
1652 record" to see the obtained buffer size.
1654 set debug linux-namespaces
1655 show debug linux-namespaces
1656 Control display of debugging info regarding Linux namespaces.
1658 set|show record btrace pt buffer-size
1659 Set and show the size of the ring buffer used for branch tracing in
1660 Intel Processor Trace format.
1661 The obtained size may differ from the requested size. Use "info
1662 record" to see the obtained buffer size.
1664 maint set|show btrace pt skip-pad
1665 Set and show whether PAD packets are skipped when computing the
1668 * The command 'thread apply all' can now support new option '-ascending'
1669 to call its specified command for all threads in ascending order.
1671 * Python/Guile scripting
1673 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1674 special section named `.debug_gdb_scripts'.
1676 * New remote packets
1678 qXfer:btrace-conf:read
1679 Return the branch trace configuration for the current thread.
1681 Qbtrace-conf:bts:size
1682 Set the requested ring buffer size for branch tracing in BTS format.
1685 Enable Intel Procesor Trace-based branch tracing for the current
1686 process. The remote stub reports support for this packet to GDB's
1689 Qbtrace-conf:pt:size
1690 Set the requested ring buffer size for branch tracing in Intel Processor
1694 Indicates a memory breakpoint instruction was executed, irrespective
1695 of whether it was GDB that planted the breakpoint or the breakpoint
1696 is hardcoded in the program. This is required for correct non-stop
1700 Indicates the target stopped for a hardware breakpoint. This is
1701 required for correct non-stop mode operation.
1704 Return information about files on the remote system.
1706 qXfer:exec-file:read
1707 Return the full absolute name of the file that was executed to
1708 create a process running on the remote system.
1711 Select the filesystem on which vFile: operations with filename
1712 arguments will operate. This is required for GDB to be able to
1713 access files on remote targets where the remote stub does not
1714 share a common filesystem with the inferior(s).
1717 Indicates that a fork system call was executed.
1720 Indicates that a vfork system call was executed.
1722 vforkdone stop reason
1723 Indicates that a vfork child of the specified process has executed
1724 an exec or exit, allowing the vfork parent to resume execution.
1726 fork-events and vfork-events features in qSupported
1727 The qSupported packet allows GDB to request support for fork and
1728 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1729 and the qSupported response can contain the corresponding
1730 'stubfeatures'. Set and show commands can be used to display
1731 whether these features are enabled.
1733 * Extended-remote fork events
1735 ** GDB now has support for fork events on extended-remote Linux
1736 targets. For targets with Linux kernels 2.5.60 and later, this
1737 enables follow-fork-mode and detach-on-fork for both fork and
1738 vfork, as well as fork and vfork catchpoints.
1740 * The info record command now shows the recording format and the
1741 branch tracing configuration for the current thread when using
1742 the btrace record target.
1743 For the BTS format, it shows the ring buffer size.
1745 * GDB now has support for DTrace USDT (Userland Static Defined
1746 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1748 * GDB now supports access to vector registers on S/390 GNU/Linux
1751 * Removed command line options
1753 -xdb HP-UX XDB compatibility mode.
1755 * Removed targets and native configurations
1757 HP/PA running HP-UX hppa*-*-hpux*
1758 Itanium running HP-UX ia64-*-hpux*
1760 * New configure options
1763 This configure option allows the user to build GDB with support for
1764 Intel Processor Trace (default: auto). This requires libipt.
1766 --with-libipt-prefix=PATH
1767 Specify the path to the version of libipt that GDB should use.
1768 $PATH/include should contain the intel-pt.h header and
1769 $PATH/lib should contain the libipt.so library.
1771 *** Changes in GDB 7.9.1
1775 ** Xmethods can now specify a result type.
1777 *** Changes in GDB 7.9
1779 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1783 ** You can now access frame registers from Python scripts.
1784 ** New attribute 'producer' for gdb.Symtab objects.
1785 ** gdb.Objfile objects have a new attribute "progspace",
1786 which is the gdb.Progspace object of the containing program space.
1787 ** gdb.Objfile objects have a new attribute "owner".
1788 ** gdb.Objfile objects have a new attribute "build_id",
1789 which is the build ID generated when the file was built.
1790 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1791 ** A new event "gdb.clear_objfiles" has been added, triggered when
1792 selecting a new file to debug.
1793 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1794 ** New function gdb.lookup_objfile.
1796 New events which are triggered when GDB modifies the state of the
1799 ** gdb.events.inferior_call_pre: Function call is about to be made.
1800 ** gdb.events.inferior_call_post: Function call has just been made.
1801 ** gdb.events.memory_changed: A memory location has been altered.
1802 ** gdb.events.register_changed: A register has been altered.
1804 * New Python-based convenience functions:
1806 ** $_caller_is(name [, number_of_frames])
1807 ** $_caller_matches(regexp [, number_of_frames])
1808 ** $_any_caller_is(name [, number_of_frames])
1809 ** $_any_caller_matches(regexp [, number_of_frames])
1811 * GDB now supports the compilation and injection of source code into
1812 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1813 to compile the source code to object code, and if successful, inject
1814 and execute that code within the current context of the inferior.
1815 Currently the C language is supported. The commands used to
1816 interface with this new feature are:
1818 compile code [-raw|-r] [--] [source code]
1819 compile file [-raw|-r] filename
1823 demangle [-l language] [--] name
1824 Demangle "name" in the specified language, or the current language
1825 if elided. This command is renamed from the "maint demangle" command.
1826 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1827 as "maint demangler-warning".
1829 queue-signal signal-name-or-number
1830 Queue a signal to be delivered to the thread when it is resumed.
1832 add-auto-load-scripts-directory directory
1833 Add entries to the list of directories from which to load auto-loaded
1836 maint print user-registers
1837 List all currently available "user" registers.
1839 compile code [-r|-raw] [--] [source code]
1840 Compile, inject, and execute in the inferior the executable object
1841 code produced by compiling the provided source code.
1843 compile file [-r|-raw] filename
1844 Compile and inject into the inferior the executable object code
1845 produced by compiling the source code stored in the filename
1848 * On resume, GDB now always passes the signal the program had stopped
1849 for to the thread the signal was sent to, even if the user changed
1850 threads before resuming. Previously GDB would often (but not
1851 always) deliver the signal to the thread that happens to be current
1854 * Conversely, the "signal" command now consistently delivers the
1855 requested signal to the current thread. GDB now asks for
1856 confirmation if the program had stopped for a signal and the user
1857 switched threads meanwhile.
1859 * "breakpoint always-inserted" modes "off" and "auto" merged.
1861 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1862 won't remove breakpoints from the target until all threads stop,
1863 even in non-stop mode. The "auto" mode has been removed, and "off"
1864 is now the default mode.
1868 set debug symbol-lookup
1869 show debug symbol-lookup
1870 Control display of debugging info regarding symbol lookup.
1874 ** The -list-thread-groups command outputs an exit-code field for
1875 inferiors that have exited.
1879 MIPS SDE mips*-sde*-elf*
1883 Support for these obsolete configurations has been removed.
1885 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1886 SGI Irix-5.x mips-*-irix5*
1887 SGI Irix-6.x mips-*-irix6*
1888 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1889 VAX running Ultrix vax-*-ultrix*
1891 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1892 and "assf"), have been removed. Use the "sharedlibrary" command, or
1893 its alias "share", instead.
1895 *** Changes in GDB 7.8
1897 * New command line options
1900 This is an alias for the --data-directory option.
1902 * GDB supports printing and modifying of variable length automatic arrays
1903 as specified in ISO C99.
1905 * The ARM simulator now supports instruction level tracing
1906 with or without disassembly.
1910 GDB now has support for scripting using Guile. Whether this is
1911 available is determined at configure time.
1912 Guile version 2.0 or greater is required.
1913 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1915 * New commands (for set/show, see "New options" below)
1919 Invoke CODE by passing it to the Guile interpreter.
1923 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1925 info auto-load guile-scripts [regexp]
1926 Print the list of automatically loaded Guile scripts.
1928 * The source command is now capable of sourcing Guile scripts.
1929 This feature is dependent on the debugger being built with Guile support.
1933 set print symbol-loading (off|brief|full)
1934 show print symbol-loading
1935 Control whether to print informational messages when loading symbol
1936 information for a file. The default is "full", but when debugging
1937 programs with large numbers of shared libraries the amount of output
1938 becomes less useful.
1940 set guile print-stack (none|message|full)
1941 show guile print-stack
1942 Show a stack trace when an error is encountered in a Guile script.
1944 set auto-load guile-scripts (on|off)
1945 show auto-load guile-scripts
1946 Control auto-loading of Guile script files.
1948 maint ada set ignore-descriptive-types (on|off)
1949 maint ada show ignore-descriptive-types
1950 Control whether the debugger should ignore descriptive types in Ada
1951 programs. The default is not to ignore the descriptive types. See
1952 the user manual for more details on descriptive types and the intended
1953 usage of this option.
1955 set auto-connect-native-target
1957 Control whether GDB is allowed to automatically connect to the
1958 native target for the run, attach, etc. commands when not connected
1959 to any target yet. See also "target native" below.
1961 set record btrace replay-memory-access (read-only|read-write)
1962 show record btrace replay-memory-access
1963 Control what memory accesses are allowed during replay.
1965 maint set target-async (on|off)
1966 maint show target-async
1967 This controls whether GDB targets operate in synchronous or
1968 asynchronous mode. Normally the default is asynchronous, if it is
1969 available; but this can be changed to more easily debug problems
1970 occurring only in synchronous mode.
1972 set mi-async (on|off)
1974 Control whether MI asynchronous mode is preferred. This supersedes
1975 "set target-async" of previous GDB versions.
1977 * "set target-async" is deprecated as a CLI option and is now an alias
1978 for "set mi-async" (only puts MI into async mode).
1980 * Background execution commands (e.g., "c&", "s&", etc.) are now
1981 possible ``out of the box'' if the target supports them. Previously
1982 the user would need to explicitly enable the possibility with the
1983 "set target-async on" command.
1985 * New features in the GDB remote stub, GDBserver
1987 ** New option --debug-format=option1[,option2,...] allows one to add
1988 additional text to each output. At present only timestamps
1989 are supported: --debug-format=timestamps.
1990 Timestamps can also be turned on with the
1991 "monitor set debug-format timestamps" command from GDB.
1993 * The 'record instruction-history' command now starts counting instructions
1994 at one. This also affects the instruction ranges reported by the
1995 'record function-call-history' command when given the /i modifier.
1997 * The command 'record function-call-history' supports a new modifier '/c' to
1998 indent the function names based on their call stack depth.
1999 The fields for the '/i' and '/l' modifier have been reordered.
2000 The source line range is now prefixed with 'at'.
2001 The instruction range is now prefixed with 'inst'.
2002 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2003 "record instruction-history" and "list" commands.
2005 * The ranges given as arguments to the 'record function-call-history' and
2006 'record instruction-history' commands are now inclusive.
2008 * The btrace record target now supports the 'record goto' command.
2009 For locations inside the execution trace, the back trace is computed
2010 based on the information stored in the execution trace.
2012 * The btrace record target supports limited reverse execution and replay.
2013 The target does not record data and therefore does not allow reading
2014 memory or registers.
2016 * The "catch syscall" command now works on s390*-linux* targets.
2018 * The "compare-sections" command is no longer specific to target
2019 remote. It now works with all targets.
2021 * All native targets are now consistently called "native".
2022 Consequently, the "target child", "target GNU", "target djgpp",
2023 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2024 commands have been replaced with "target native". The QNX/NTO port
2025 leaves the "procfs" target in place and adds a "native" target for
2026 consistency with other ports. The impact on users should be minimal
2027 as these commands previously either throwed an error, or were
2028 no-ops. The target's name is visible in the output of the following
2029 commands: "help target", "info target", "info files", "maint print
2032 * The "target native" command now connects to the native target. This
2033 can be used to launch native programs even when "set
2034 auto-connect-native-target" is set to off.
2036 * GDB now supports access to Intel MPX registers on GNU/Linux.
2038 * Support for Intel AVX-512 registers on GNU/Linux.
2039 Support displaying and modifying Intel AVX-512 registers
2040 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2042 * New remote packets
2044 qXfer:btrace:read's annex
2045 The qXfer:btrace:read packet supports a new annex 'delta' to read
2046 branch trace incrementally.
2050 ** Valid Python operations on gdb.Value objects representing
2051 structs/classes invoke the corresponding overloaded operators if
2053 ** New `Xmethods' feature in the Python API. Xmethods are
2054 additional methods or replacements for existing methods of a C++
2055 class. This feature is useful for those cases where a method
2056 defined in C++ source code could be inlined or optimized out by
2057 the compiler, making it unavailable to GDB.
2060 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2062 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2063 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2064 its alias "share", instead.
2066 * The commands "set remotebaud" and "show remotebaud" are no longer
2067 supported. Use "set serial baud" and "show serial baud" (respectively)
2072 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2073 target-async". The latter is left as a deprecated alias of the
2074 former for backward compatibility. If the target supports it,
2075 CLI background execution commands are now always possible by
2076 default, independently of whether the frontend stated a
2077 preference for asynchronous execution with "-gdb-set mi-async".
2078 Previously "-gdb-set target-async off" affected both MI execution
2079 commands and CLI execution commands.
2081 *** Changes in GDB 7.7
2083 * Improved support for process record-replay and reverse debugging on
2084 arm*-linux* targets. Support for thumb32 and syscall instruction
2085 recording has been added.
2087 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2089 * GDB now supports Fission DWP file format version 2.
2090 http://gcc.gnu.org/wiki/DebugFission
2092 * New convenience function "$_isvoid", to check whether an expression
2093 is void. A void expression is an expression where the type of the
2094 result is "void". For example, some convenience variables may be
2095 "void" when evaluated (e.g., "$_exitcode" before the execution of
2096 the program being debugged; or an undefined convenience variable).
2097 Another example, when calling a function whose return type is
2100 * The "maintenance print objfiles" command now takes an optional regexp.
2102 * The "catch syscall" command now works on arm*-linux* targets.
2104 * GDB now consistently shows "<not saved>" when printing values of
2105 registers the debug info indicates have not been saved in the frame
2106 and there's nowhere to retrieve them from
2107 (callee-saved/call-clobbered registers):
2112 (gdb) info registers rax
2115 Before, the former would print "<optimized out>", and the latter
2116 "*value not available*".
2118 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2123 ** Frame filters and frame decorators have been added.
2124 ** Temporary breakpoints are now supported.
2125 ** Line tables representation has been added.
2126 ** New attribute 'parent_type' for gdb.Field objects.
2127 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2128 ** New attribute 'name' for gdb.Type objects.
2132 Nios II ELF nios2*-*-elf
2133 Nios II GNU/Linux nios2*-*-linux
2134 Texas Instruments MSP430 msp430*-*-elf
2136 * Removed native configurations
2138 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2139 been removed. ELF variants of these configurations are kept supported.
2141 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2142 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2143 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2144 i[34567]86-*-openbsd3.[0-3]
2145 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2146 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2147 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2151 Like "catch throw", but catches a re-thrown exception.
2152 maint check-psymtabs
2153 Renamed from old "maint check-symtabs".
2155 Perform consistency checks on symtabs.
2156 maint expand-symtabs
2157 Expand symtabs matching an optional regexp.
2160 Display the details of GDB configure-time options.
2162 maint set|show per-command
2163 maint set|show per-command space
2164 maint set|show per-command time
2165 maint set|show per-command symtab
2166 Enable display of per-command gdb resource usage.
2168 remove-symbol-file FILENAME
2169 remove-symbol-file -a ADDRESS
2170 Remove a symbol file added via add-symbol-file. The file to remove
2171 can be identified by its filename or by an address that lies within
2172 the boundaries of this symbol file in memory.
2175 info exceptions REGEXP
2176 Display the list of Ada exceptions defined in the program being
2177 debugged. If provided, only the exceptions whose names match REGEXP
2182 set debug symfile off|on
2184 Control display of debugging info regarding reading symbol files and
2185 symbol tables within those files
2187 set print raw frame-arguments
2188 show print raw frame-arguments
2189 Set/show whether to print frame arguments in raw mode,
2190 disregarding any defined pretty-printers.
2192 set remote trace-status-packet
2193 show remote trace-status-packet
2194 Set/show the use of remote protocol qTStatus packet.
2198 Control display of debugging messages related to Nios II targets.
2202 Control whether target-assisted range stepping is enabled.
2204 set startup-with-shell
2205 show startup-with-shell
2206 Specifies whether Unix child processes are started via a shell or
2211 Use the target memory cache for accesses to the code segment. This
2212 improves performance of remote debugging (particularly disassembly).
2214 * You can now use a literal value 'unlimited' for options that
2215 interpret 0 or -1 as meaning "unlimited". E.g., "set
2216 trace-buffer-size unlimited" is now an alias for "set
2217 trace-buffer-size -1" and "set height unlimited" is now an alias for
2220 * The "set debug symtab-create" debugging option of GDB has been changed to
2221 accept a verbosity level. 0 means "off", 1 provides basic debugging
2222 output, and values of 2 or greater provides more verbose output.
2224 * New command-line options
2226 Display the details of GDB configure-time options.
2228 * The command 'tsave' can now support new option '-ctf' to save trace
2229 buffer in Common Trace Format.
2231 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2234 * GDB now implements the the C++ 'typeid' operator.
2236 * The new convenience variable $_exception holds the exception being
2237 thrown or caught at an exception-related catchpoint.
2239 * The exception-related catchpoints, like "catch throw", now accept a
2240 regular expression which can be used to filter exceptions by type.
2242 * The new convenience variable $_exitsignal is automatically set to
2243 the terminating signal number when the program being debugged dies
2244 due to an uncaught signal.
2248 ** All MI commands now accept an optional "--language" option.
2249 Support for this feature can be verified by using the "-list-features"
2250 command, which should contain "language-option".
2252 ** The new command -info-gdb-mi-command allows the user to determine
2253 whether a GDB/MI command is supported or not.
2255 ** The "^error" result record returned when trying to execute an undefined
2256 GDB/MI command now provides a variable named "code" whose content is the
2257 "undefined-command" error code. Support for this feature can be verified
2258 by using the "-list-features" command, which should contain
2259 "undefined-command-error-code".
2261 ** The -trace-save MI command can optionally save trace buffer in Common
2264 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2266 ** The command -data-list-register-values now accepts an optional
2267 "--skip-unavailable" option. When used, only the available registers
2270 ** The new command -trace-frame-collected dumps collected variables,
2271 computed expressions, tvars, memory and registers in a traceframe.
2273 ** The commands -stack-list-locals, -stack-list-arguments and
2274 -stack-list-variables now accept an option "--skip-unavailable".
2275 When used, only the available locals or arguments are displayed.
2277 ** The -exec-run command now accepts an optional "--start" option.
2278 When used, the command follows the same semantics as the "start"
2279 command, stopping the program's execution at the start of its
2280 main subprogram. Support for this feature can be verified using
2281 the "-list-features" command, which should contain
2282 "exec-run-start-option".
2284 ** The new commands -catch-assert and -catch-exceptions insert
2285 catchpoints stopping the program when Ada exceptions are raised.
2287 ** The new command -info-ada-exceptions provides the equivalent of
2288 the new "info exceptions" command.
2290 * New system-wide configuration scripts
2291 A GDB installation now provides scripts suitable for use as system-wide
2292 configuration scripts for the following systems:
2296 * GDB now supports target-assigned range stepping with remote targets.
2297 This improves the performance of stepping source lines by reducing
2298 the number of control packets from/to GDB. See "New remote packets"
2301 * GDB now understands the element 'tvar' in the XML traceframe info.
2302 It has the id of the collected trace state variables.
2304 * On S/390 targets that provide the transactional-execution feature,
2305 the program interruption transaction diagnostic block (TDB) is now
2306 represented as a number of additional "registers" in GDB.
2308 * New remote packets
2312 The vCont packet supports a new 'r' action, that tells the remote
2313 stub to step through an address range itself, without GDB
2314 involvemement at each single-step.
2316 qXfer:libraries-svr4:read's annex
2317 The previously unused annex of the qXfer:libraries-svr4:read packet
2318 is now used to support passing an argument list. The remote stub
2319 reports support for this argument list to GDB's qSupported query.
2320 The defined arguments are "start" and "prev", used to reduce work
2321 necessary for library list updating, resulting in significant
2324 * New features in the GDB remote stub, GDBserver
2326 ** GDBserver now supports target-assisted range stepping. Currently
2327 enabled on x86/x86_64 GNU/Linux targets.
2329 ** GDBserver now adds element 'tvar' in the XML in the reply to
2330 'qXfer:traceframe-info:read'. It has the id of the collected
2331 trace state variables.
2333 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2336 * New 'z' formatter for printing and examining memory, this displays the
2337 value as hexadecimal zero padded on the left to the size of the type.
2339 * GDB can now use Windows x64 unwinding data.
2341 * The "set remotebaud" command has been replaced by "set serial baud".
2342 Similarly, "show remotebaud" has been replaced by "show serial baud".
2343 The "set remotebaud" and "show remotebaud" commands are still available
2344 to provide backward compatibility with older versions of GDB.
2346 *** Changes in GDB 7.6
2348 * Target record has been renamed to record-full.
2349 Record/replay is now enabled with the "record full" command.
2350 This also affects settings that are associated with full record/replay
2351 that have been moved from "set/show record" to "set/show record full":
2353 set|show record full insn-number-max
2354 set|show record full stop-at-limit
2355 set|show record full memory-query
2357 * A new record target "record-btrace" has been added. The new target
2358 uses hardware support to record the control-flow of a process. It
2359 does not support replaying the execution, but it implements the
2360 below new commands for investigating the recorded execution log.
2361 This new recording method can be enabled using:
2365 The "record-btrace" target is only available on Intel Atom processors
2366 and requires a Linux kernel 2.6.32 or later.
2368 * Two new commands have been added for record/replay to give information
2369 about the recorded execution without having to replay the execution.
2370 The commands are only supported by "record btrace".
2372 record instruction-history prints the execution history at
2373 instruction granularity
2375 record function-call-history prints the execution history at
2376 function granularity
2378 * New native configurations
2380 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2381 FreeBSD/powerpc powerpc*-*-freebsd
2382 x86_64/Cygwin x86_64-*-cygwin*
2383 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2387 ARM AArch64 aarch64*-*-elf
2388 ARM AArch64 GNU/Linux aarch64*-*-linux
2389 Lynx 178 PowerPC powerpc-*-lynx*178
2390 x86_64/Cygwin x86_64-*-cygwin*
2391 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2393 * If the configured location of system.gdbinit file (as given by the
2394 --with-system-gdbinit option at configure time) is in the
2395 data-directory (as specified by --with-gdb-datadir at configure
2396 time) or in one of its subdirectories, then GDB will look for the
2397 system-wide init file in the directory specified by the
2398 --data-directory command-line option.
2400 * New command line options:
2402 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2403 other initialization files, unlike -nx which disables all of them.
2405 * Removed command line options
2407 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2410 * The 'ptype' and 'whatis' commands now accept an argument to control
2413 * 'info proc' now works on some core files.
2417 ** Vectors can be created with gdb.Type.vector.
2419 ** Python's atexit.register now works in GDB.
2421 ** Types can be pretty-printed via a Python API.
2423 ** Python 3 is now supported (in addition to Python 2.4 or later)
2425 ** New class gdb.Architecture exposes GDB's internal representation
2426 of architecture in the Python API.
2428 ** New method Frame.architecture returns the gdb.Architecture object
2429 corresponding to the frame's architecture.
2431 * New Python-based convenience functions:
2433 ** $_memeq(buf1, buf2, length)
2434 ** $_streq(str1, str2)
2436 ** $_regex(str, regex)
2438 * The 'cd' command now defaults to using '~' (the home directory) if not
2441 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2442 default for GCC since November 2000.
2444 * The command 'forward-search' can now be abbreviated as 'fo'.
2446 * The command 'info tracepoints' can now display 'installed on target'
2447 or 'not installed on target' for each non-pending location of tracepoint.
2449 * New configure options
2451 --enable-libmcheck/--disable-libmcheck
2452 By default, development versions are built with -lmcheck on hosts
2453 that support it, in order to help track memory corruption issues.
2454 Release versions, on the other hand, are built without -lmcheck
2455 by default. The --enable-libmcheck/--disable-libmcheck configure
2456 options allow the user to override that default.
2457 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2458 This configure option allows the user to build GDB with
2459 libbabeltrace using which GDB can read Common Trace Format data.
2461 * New commands (for set/show, see "New options" below)
2464 Catch signals. This is similar to "handle", but allows commands and
2465 conditions to be attached.
2468 List the BFDs known to GDB.
2470 python-interactive [command]
2472 Start a Python interactive prompt, or evaluate the optional command
2473 and print the result of expressions.
2476 "py" is a new alias for "python".
2478 enable type-printer [name]...
2479 disable type-printer [name]...
2480 Enable or disable type printers.
2484 ** For the Renesas Super-H architecture, the "regs" command has been removed
2485 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2490 set print type methods (on|off)
2491 show print type methods
2492 Control whether method declarations are displayed by "ptype".
2493 The default is to show them.
2495 set print type typedefs (on|off)
2496 show print type typedefs
2497 Control whether typedef definitions are displayed by "ptype".
2498 The default is to show them.
2500 set filename-display basename|relative|absolute
2501 show filename-display
2502 Control the way in which filenames is displayed.
2503 The default is "relative", which preserves previous behavior.
2505 set trace-buffer-size
2506 show trace-buffer-size
2507 Request target to change the size of trace buffer.
2509 set remote trace-buffer-size-packet auto|on|off
2510 show remote trace-buffer-size-packet
2511 Control the use of the remote protocol `QTBuffer:size' packet.
2515 Control display of debugging messages related to ARM AArch64.
2518 set debug coff-pe-read
2519 show debug coff-pe-read
2520 Control display of debugging messages related to reading of COFF/PE
2525 Control display of debugging messages related to Mach-O symbols
2528 set debug notification
2529 show debug notification
2530 Control display of debugging info for async remote notification.
2534 ** Command parameter changes are now notified using new async record
2535 "=cmd-param-changed".
2536 ** Trace frame changes caused by command "tfind" are now notified using
2537 new async record "=traceframe-changed".
2538 ** The creation, deletion and modification of trace state variables
2539 are now notified using new async records "=tsv-created",
2540 "=tsv-deleted" and "=tsv-modified".
2541 ** The start and stop of process record are now notified using new
2542 async record "=record-started" and "=record-stopped".
2543 ** Memory changes are now notified using new async record
2545 ** The data-disassemble command response will include a "fullname" field
2546 containing the absolute file name when source has been requested.
2547 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2548 command, to allow pattern filling of memory areas.
2549 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2550 library load/unload events.
2551 ** The response to breakpoint commands and breakpoint async records
2552 includes an "installed" field containing a boolean state about each
2553 non-pending tracepoint location is whether installed on target or not.
2554 ** Output of the "-trace-status" command includes a "trace-file" field
2555 containing the name of the trace file being examined. This field is
2556 optional, and only present when examining a trace file.
2557 ** The "fullname" field is now always present along with the "file" field,
2558 even if the file cannot be found by GDB.
2560 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2561 You must have the LZMA library available when configuring GDB for this
2562 feature to be enabled. For more information, see:
2563 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2565 * New remote packets
2568 Set the size of trace buffer. The remote stub reports support for this
2569 packet to gdb's qSupported query.
2572 Enable Branch Trace Store (BTS)-based branch tracing for the current
2573 thread. The remote stub reports support for this packet to gdb's
2577 Disable branch tracing for the current thread. The remote stub reports
2578 support for this packet to gdb's qSupported query.
2581 Read the traced branches for the current thread. The remote stub
2582 reports support for this packet to gdb's qSupported query.
2584 *** Changes in GDB 7.5
2586 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2587 for more x32 ABI info.
2589 * GDB now supports access to MIPS DSP registers on Linux targets.
2591 * GDB now supports debugging microMIPS binaries.
2593 * The "info os" command on GNU/Linux can now display information on
2594 several new classes of objects managed by the operating system:
2595 "info os procgroups" lists process groups
2596 "info os files" lists file descriptors
2597 "info os sockets" lists internet-domain sockets
2598 "info os shm" lists shared-memory regions
2599 "info os semaphores" lists semaphores
2600 "info os msg" lists message queues
2601 "info os modules" lists loaded kernel modules
2603 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2604 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2605 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2606 options and inspect the probe arguments using the new $_probe_arg family
2607 of convenience variables. You can obtain more information about SystemTap
2608 in <http://sourceware.org/systemtap/>.
2610 * GDB now supports reversible debugging on ARM, it allows you to
2611 debug basic ARM and THUMB instructions, and provides
2612 record/replay support.
2614 * The option "symbol-reloading" has been deleted as it is no longer used.
2618 ** GDB commands implemented in Python can now be put in command class
2621 ** The "maint set python print-stack on|off" is now deleted.
2623 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2624 apply "flag enum"-style pretty-printing to any enum.
2626 ** gdb.lookup_symbol can now work when there is no current frame.
2628 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2629 the source at which the symbol was defined.
2631 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2632 method 'value'. The former indicates whether the symbol needs a
2633 frame in order to compute its value, and the latter computes the
2636 ** A new method 'referenced_value' on gdb.Value objects which can
2637 dereference pointer as well as C++ reference values.
2639 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2640 which return the global and static blocks (as gdb.Block objects),
2641 of the underlying symbol table, respectively.
2643 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2644 object associated with a PC value.
2646 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2647 of the address range occupied by code for the current source line.
2649 * Go language support.
2650 GDB now supports debugging programs written in the Go programming
2653 * GDBserver now supports stdio connections.
2654 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2656 * The binary "gdbtui" can no longer be built or installed.
2657 Use "gdb -tui" instead.
2659 * GDB will now print "flag" enums specially. A flag enum is one where
2660 all the enumerator values have no bits in common when pairwise
2661 "and"ed. When printing a value whose type is a flag enum, GDB will
2662 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2663 (gdb) print (enum E) 3
2666 * The filename part of a linespec will now match trailing components
2667 of a source file name. For example, "break gcc/expr.c:1000" will
2668 now set a breakpoint in build/gcc/expr.c, but not
2669 build/libcpp/expr.c.
2671 * The "info proc" and "generate-core-file" commands will now also
2672 work on remote targets connected to GDBserver on Linux.
2674 * The command "info catch" has been removed. It has been disabled
2675 since December 2007.
2677 * The "catch exception" and "catch assert" commands now accept
2678 a condition at the end of the command, much like the "break"
2679 command does. For instance:
2681 (gdb) catch exception Constraint_Error if Barrier = True
2683 Previously, it was possible to add a condition to such catchpoints,
2684 but it had to be done as a second step, after the catchpoint had been
2685 created, using the "condition" command.
2687 * The "info static-tracepoint-marker" command will now also work on
2688 native Linux targets with in-process agent.
2690 * GDB can now set breakpoints on inlined functions.
2692 * The .gdb_index section has been updated to include symbols for
2693 inlined functions. GDB will ignore older .gdb_index sections by
2694 default, which could cause symbol files to be loaded more slowly
2695 until their .gdb_index sections can be recreated. The new command
2696 "set use-deprecated-index-sections on" will cause GDB to use any older
2697 .gdb_index sections it finds. This will restore performance, but the
2698 ability to set breakpoints on inlined functions will be lost in symbol
2699 files with older .gdb_index sections.
2701 The .gdb_index section has also been updated to record more information
2702 about each symbol. This speeds up the "info variables", "info functions"
2703 and "info types" commands when used with programs having the .gdb_index
2704 section, as well as speeding up debugging with shared libraries using
2705 the .gdb_index section.
2707 * Ada support for GDB/MI Variable Objects has been added.
2709 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2714 ** New command -info-os is the MI equivalent of "info os".
2716 ** Output logs ("set logging" and related) now include MI output.
2720 ** "set use-deprecated-index-sections on|off"
2721 "show use-deprecated-index-sections on|off"
2722 Controls the use of deprecated .gdb_index sections.
2724 ** "catch load" and "catch unload" can be used to stop when a shared
2725 library is loaded or unloaded, respectively.
2727 ** "enable count" can be used to auto-disable a breakpoint after
2730 ** "info vtbl" can be used to show the virtual method tables for
2731 C++ and Java objects.
2733 ** "explore" and its sub commands "explore value" and "explore type"
2734 can be used to recursively explore values and types of
2735 expressions. These commands are available only if GDB is
2736 configured with '--with-python'.
2738 ** "info auto-load" shows status of all kinds of auto-loaded files,
2739 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2740 sequences of commands files, "info auto-load python-scripts"
2741 shows status of auto-loading Python script files,
2742 "info auto-load local-gdbinit" shows status of loading init file
2743 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2744 status of inferior specific thread debugging shared library loading.
2746 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2747 and "show auto-load-scripts" commands have been deprecated, use their
2748 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2749 and "show auto-load python-scripts" counterparts instead.
2751 ** "dprintf location,format,args..." creates a dynamic printf, which
2752 is basically a breakpoint that does a printf and immediately
2753 resumes your program's execution, so it is like a printf that you
2754 can insert dynamically at runtime instead of at compiletime.
2756 ** "set print symbol"
2758 Controls whether GDB attempts to display the symbol, if any,
2759 corresponding to addresses it prints. This defaults to "on", but
2760 you can set it to "off" to restore GDB's previous behavior.
2762 * Deprecated commands
2764 ** For the Renesas Super-H architecture, the "regs" command has been
2765 deprecated, and "info all-registers" should be used instead.
2769 Renesas RL78 rl78-*-elf
2770 HP OpenVMS ia64 ia64-hp-openvms*
2772 * GDBserver supports evaluation of breakpoint conditions. When
2773 support is advertised by GDBserver, GDB may be told to send the
2774 breakpoint conditions in bytecode form to GDBserver. GDBserver
2775 will only report the breakpoint trigger to GDB when its condition
2780 set mips compression
2781 show mips compression
2782 Select the compressed ISA encoding used in functions that have no symbol
2783 information available. The encoding can be set to either of:
2786 and is updated automatically from ELF file flags if available.
2788 set breakpoint condition-evaluation
2789 show breakpoint condition-evaluation
2790 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2791 GDBserver ("target"). Default option "auto" chooses the most efficient
2793 This option can improve debugger efficiency depending on the speed of the
2797 Disable auto-loading globally.
2800 Show auto-loading setting of all kinds of auto-loaded files.
2802 set auto-load gdb-scripts on|off
2803 show auto-load gdb-scripts
2804 Control auto-loading of GDB canned sequences of commands files.
2806 set auto-load python-scripts on|off
2807 show auto-load python-scripts
2808 Control auto-loading of Python script files.
2810 set auto-load local-gdbinit on|off
2811 show auto-load local-gdbinit
2812 Control loading of init file (.gdbinit) from current directory.
2814 set auto-load libthread-db on|off
2815 show auto-load libthread-db
2816 Control auto-loading of inferior specific thread debugging shared library.
2818 set auto-load scripts-directory <dir1>[:<dir2>...]
2819 show auto-load scripts-directory
2820 Set a list of directories from which to load auto-loaded scripts.
2821 Automatically loaded Python scripts and GDB scripts are located in one
2822 of the directories listed by this option.
2823 The delimiter (':' above) may differ according to the host platform.
2825 set auto-load safe-path <dir1>[:<dir2>...]
2826 show auto-load safe-path
2827 Set a list of directories from which it is safe to auto-load files.
2828 The delimiter (':' above) may differ according to the host platform.
2830 set debug auto-load on|off
2831 show debug auto-load
2832 Control display of debugging info for auto-loading the files above.
2834 set dprintf-style gdb|call|agent
2836 Control the way in which a dynamic printf is performed; "gdb"
2837 requests a GDB printf command, while "call" causes dprintf to call a
2838 function in the inferior. "agent" requests that the target agent
2839 (such as GDBserver) do the printing.
2841 set dprintf-function <expr>
2842 show dprintf-function
2843 set dprintf-channel <expr>
2844 show dprintf-channel
2845 Set the function and optional first argument to the call when using
2846 the "call" style of dynamic printf.
2848 set disconnected-dprintf on|off
2849 show disconnected-dprintf
2850 Control whether agent-style dynamic printfs continue to be in effect
2851 after GDB disconnects.
2853 * New configure options
2855 --with-auto-load-dir
2856 Configure default value for the 'set auto-load scripts-directory'
2857 setting above. It defaults to '$debugdir:$datadir/auto-load',
2858 $debugdir representing global debugging info directories (available
2859 via 'show debug-file-directory') and $datadir representing GDB's data
2860 directory (available via 'show data-directory').
2862 --with-auto-load-safe-path
2863 Configure default value for the 'set auto-load safe-path' setting
2864 above. It defaults to the --with-auto-load-dir setting.
2866 --without-auto-load-safe-path
2867 Set 'set auto-load safe-path' to '/', effectively disabling this
2870 * New remote packets
2872 z0/z1 conditional breakpoints extension
2874 The z0/z1 breakpoint insertion packets have been extended to carry
2875 a list of conditional expressions over to the remote stub depending on the
2876 condition evaluation mode. The use of this extension can be controlled
2877 via the "set remote conditional-breakpoints-packet" command.
2881 Specify the signals which the remote stub may pass to the debugged
2882 program without GDB involvement.
2884 * New command line options
2886 --init-command=FILE, -ix Like --command, -x but execute it
2887 before loading inferior.
2888 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2889 execute it before loading inferior.
2891 *** Changes in GDB 7.4
2893 * GDB now handles ambiguous linespecs more consistently; the existing
2894 FILE:LINE support has been expanded to other types of linespecs. A
2895 breakpoint will now be set on all matching locations in all
2896 inferiors, and locations will be added or removed according to
2899 * GDB now allows you to skip uninteresting functions and files when
2900 stepping with the "skip function" and "skip file" commands.
2902 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2903 and "show remote hardware-watchpoint-length-limit". These allows to
2904 set or show the maximum length limit (in bytes) of a remote
2905 target hardware watchpoint.
2907 This allows e.g. to use "unlimited" hardware watchpoints with the
2908 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2909 watchpoints are slower than real hardware watchpoints but are
2910 significantly faster than gdb software watchpoints.
2914 ** The register_pretty_printer function in module gdb.printing now takes
2915 an optional `replace' argument. If True, the new printer replaces any
2918 ** The "maint set python print-stack on|off" command has been
2919 deprecated and will be deleted in GDB 7.5.
2920 A new command: "set python print-stack none|full|message" has
2921 replaced it. Additionally, the default for "print-stack" is
2922 now "message", which just prints the error message without
2925 ** A prompt substitution hook (prompt_hook) is now available to the
2928 ** A new Python module, gdb.prompt has been added to the GDB Python
2929 modules library. This module provides functionality for
2930 escape sequences in prompts (used by set/show
2931 extended-prompt). These escape sequences are replaced by their
2932 corresponding value.
2934 ** Python commands and convenience-functions located in
2935 'data-directory'/python/gdb/command and
2936 'data-directory'/python/gdb/function are now automatically loaded
2939 ** Blocks now provide four new attributes. global_block and
2940 static_block will return the global and static blocks
2941 respectively. is_static and is_global are boolean attributes
2942 that indicate if the block is one of those two types.
2944 ** Symbols now provide the "type" attribute, the type of the symbol.
2946 ** The "gdb.breakpoint" function has been deprecated in favor of
2949 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2950 of a function. This class is based on the "finish" command
2951 available in the CLI.
2953 ** Type objects for struct and union types now allow access to
2954 the fields using standard Python dictionary (mapping) methods.
2955 For example, "some_type['myfield']" now works, as does
2956 "some_type.items()".
2958 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2961 ** A new function, "deep_items" has been added to the gdb.types
2962 module in the GDB Python modules library. This function returns
2963 an iterator over the fields of a struct or union type. Unlike
2964 the standard Python "iteritems" method, it will recursively traverse
2965 any anonymous fields.
2969 ** "*stopped" events can report several new "reason"s, such as
2972 ** Breakpoint changes are now notified using new async records, like
2973 "=breakpoint-modified".
2975 ** New command -ada-task-info.
2977 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2978 $sdir specifies the default system locations of shared libraries.
2979 $pdir specifies the directory where the libpthread used by the application
2982 GDB no longer looks in $sdir and $pdir after it has searched the directories
2983 mentioned in libthread-db-search-path. If you want to search those
2984 directories, they must be specified in libthread-db-search-path.
2985 The default value of libthread-db-search-path on GNU/Linux and Solaris
2986 systems is now "$sdir:$pdir".
2988 $pdir is not supported by gdbserver, it is currently ignored.
2989 $sdir is supported by gdbserver.
2991 * New configure option --with-iconv-bin.
2992 When using the internationalization support like the one in the GNU C
2993 library, GDB will invoke the "iconv" program to get a list of supported
2994 character sets. If this program lives in a non-standard location, one can
2995 use this option to specify where to find it.
2997 * When natively debugging programs on PowerPC BookE processors running
2998 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2999 watchpoints, which specify a mask in addition to an address to watch.
3000 The mask specifies that some bits of an address (the bits which are
3001 reset in the mask) should be ignored when matching the address accessed
3002 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3003 section in the user manual for more details.
3005 * The new option --once causes GDBserver to stop listening for connections once
3006 the first connection is made. The listening port used by GDBserver will
3007 become available after that.
3009 * New commands "info macros" and "alias" have been added.
3011 * New function parameters suffix @entry specifies value of function parameter
3012 at the time the function got called. Entry values are available only since
3018 "!" is now an alias of the "shell" command.
3019 Note that no space is needed between "!" and SHELL COMMAND.
3023 watch EXPRESSION mask MASK_VALUE
3024 The watch command now supports the mask argument which allows creation
3025 of masked watchpoints, if the current architecture supports this feature.
3027 info auto-load-scripts [REGEXP]
3028 This command was formerly named "maintenance print section-scripts".
3029 It is now generally useful and is no longer a maintenance-only command.
3031 info macro [-all] [--] MACRO
3032 The info macro command has new options `-all' and `--'. The first for
3033 printing all definitions of a macro. The second for explicitly specifying
3034 the end of arguments and the beginning of the macro name in case the macro
3035 name starts with a hyphen.
3037 collect[/s] EXPRESSIONS
3038 The tracepoint collect command now takes an optional modifier "/s"
3039 that directs it to dereference pointer-to-character types and
3040 collect the bytes of memory up to a zero byte. The behavior is
3041 similar to what you see when you use the regular print command on a
3042 string. An optional integer following the "/s" sets a bound on the
3043 number of bytes that will be collected.
3046 The trace start command now interprets any supplied arguments as a
3047 note to be recorded with the trace run, with an effect similar to
3048 setting the variable trace-notes.
3051 The trace stop command now interprets any arguments as a note to be
3052 mentioned along with the tstatus report that the trace was stopped
3053 with a command. The effect is similar to setting the variable
3056 * Tracepoints can now be enabled and disabled at any time after a trace
3057 experiment has been started using the standard "enable" and "disable"
3058 commands. It is now possible to start a trace experiment with no enabled
3059 tracepoints; GDB will display a warning, but will allow the experiment to
3060 begin, assuming that tracepoints will be enabled as needed while the trace
3063 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3064 locations with 4-byte instructions, when they were previously
3065 limited to locations with instructions of 5 bytes or longer.
3069 set debug dwarf2-read
3070 show debug dwarf2-read
3071 Turns on or off display of debugging messages related to reading
3072 DWARF debug info. The default is off.
3074 set debug symtab-create
3075 show debug symtab-create
3076 Turns on or off display of debugging messages related to symbol table
3077 creation. The default is off.
3080 show extended-prompt
3081 Set the GDB prompt, and allow escape sequences to be inserted to
3082 display miscellaneous information (see 'help set extended-prompt'
3083 for the list of sequences). This prompt (and any information
3084 accessed through the escape sequences) is updated every time the
3085 prompt is displayed.
3087 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3088 show print entry-values
3089 Set printing of frame argument values at function entry. In some cases
3090 GDB can determine the value of function argument which was passed by the
3091 function caller, even if the value was modified inside the called function.
3093 set debug entry-values
3094 show debug entry-values
3095 Control display of debugging info for determining frame argument values at
3096 function entry and virtual tail call frames.
3098 set basenames-may-differ
3099 show basenames-may-differ
3100 Set whether a source file may have multiple base names.
3101 (A "base name" is the name of a file with the directory part removed.
3102 Example: The base name of "/home/user/hello.c" is "hello.c".)
3103 If set, GDB will canonicalize file names (e.g., expand symlinks)
3104 before comparing them. Canonicalization is an expensive operation,
3105 but it allows the same file be known by more than one base name.
3106 If not set (the default), all source files are assumed to have just
3107 one base name, and gdb will do file name comparisons more efficiently.
3113 Set a user name and notes for the current and any future trace runs.
3114 This is useful for long-running and/or disconnected traces, to
3115 inform others (or yourself) as to who is running the trace, supply
3116 contact information, or otherwise explain what is going on.
3118 set trace-stop-notes
3119 show trace-stop-notes
3120 Set a note attached to the trace run, that is displayed when the
3121 trace has been stopped by a tstop command. This is useful for
3122 instance as an explanation, if you are stopping a trace run that was
3123 started by someone else.
3125 * New remote packets
3129 Dynamically enable a tracepoint in a started trace experiment.
3133 Dynamically disable a tracepoint in a started trace experiment.
3137 Set the user and notes of the trace run.
3141 Query the current status of a tracepoint.
3145 Query the minimum length of instruction at which a fast tracepoint may
3148 * Dcache size (number of lines) and line-size are now runtime-configurable
3149 via "set dcache line" and "set dcache line-size" commands.
3153 Texas Instruments TMS320C6x tic6x-*-*
3157 Renesas RL78 rl78-*-elf
3159 *** Changes in GDB 7.3.1
3161 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3163 *** Changes in GDB 7.3
3165 * GDB has a new command: "thread find [REGEXP]".
3166 It finds the thread id whose name, target id, or thread extra info
3167 matches the given regular expression.
3169 * The "catch syscall" command now works on mips*-linux* targets.
3171 * The -data-disassemble MI command now supports modes 2 and 3 for
3172 dumping the instruction opcodes.
3174 * New command line options
3176 -data-directory DIR Specify DIR as the "data-directory".
3177 This is mostly for testing purposes.
3179 * The "maint set python auto-load on|off" command has been renamed to
3180 "set auto-load-scripts on|off".
3182 * GDB has a new command: "set directories".
3183 It is like the "dir" command except that it replaces the
3184 source path list instead of augmenting it.
3186 * GDB now understands thread names.
3188 On GNU/Linux, "info threads" will display the thread name as set by
3189 prctl or pthread_setname_np.
3191 There is also a new command, "thread name", which can be used to
3192 assign a name internally for GDB to display.
3195 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3196 has been integrated into GDB.
3200 ** The function gdb.Write now accepts an optional keyword 'stream'.
3201 This keyword, when provided, will direct the output to either
3202 stdout, stderr, or GDB's logging output.
3204 ** Parameters can now be be sub-classed in Python, and in particular
3205 you may implement the get_set_doc and get_show_doc functions.
3206 This improves how Parameter set/show documentation is processed
3207 and allows for more dynamic content.
3209 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3210 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3211 have an is_valid method.
3213 ** Breakpoints can now be sub-classed in Python, and in particular
3214 you may implement a 'stop' function that is executed each time
3215 the inferior reaches that breakpoint.
3217 ** New function gdb.lookup_global_symbol looks up a global symbol.
3219 ** GDB values in Python are now callable if the value represents a
3220 function. For example, if 'some_value' represents a function that
3221 takes two integer parameters and returns a value, you can call
3222 that function like so:
3224 result = some_value (10,20)
3226 ** Module gdb.types has been added.
3227 It contains a collection of utilities for working with gdb.Types objects:
3228 get_basic_type, has_field, make_enum_dict.
3230 ** Module gdb.printing has been added.
3231 It contains utilities for writing and registering pretty-printers.
3232 New classes: PrettyPrinter, SubPrettyPrinter,
3233 RegexpCollectionPrettyPrinter.
3234 New function: register_pretty_printer.
3236 ** New commands "info pretty-printers", "enable pretty-printer" and
3237 "disable pretty-printer" have been added.
3239 ** gdb.parameter("directories") is now available.
3241 ** New function gdb.newest_frame returns the newest frame in the
3244 ** The gdb.InferiorThread class has a new "name" attribute. This
3245 holds the thread's name.
3247 ** Python Support for Inferior events.
3248 Python scripts can add observers to be notified of events
3249 occurring in the process being debugged.
3250 The following events are currently supported:
3251 - gdb.events.cont Continue event.
3252 - gdb.events.exited Inferior exited event.
3253 - gdb.events.stop Signal received, and Breakpoint hit events.
3257 ** GDB now puts template parameters in scope when debugging in an
3258 instantiation. For example, if you have:
3260 template<int X> int func (void) { return X; }
3262 then if you step into func<5>, "print X" will show "5". This
3263 feature requires proper debuginfo support from the compiler; it
3264 was added to GCC 4.5.
3266 ** The motion commands "next", "finish", "until", and "advance" now
3267 work better when exceptions are thrown. In particular, GDB will
3268 no longer lose control of the inferior; instead, the GDB will
3269 stop the inferior at the point at which the exception is caught.
3270 This functionality requires a change in the exception handling
3271 code that was introduced in GCC 4.5.
3273 * GDB now follows GCC's rules on accessing volatile objects when
3274 reading or writing target state during expression evaluation.
3275 One notable difference to prior behavior is that "print x = 0"
3276 no longer generates a read of x; the value of the assignment is
3277 now always taken directly from the value being assigned.
3279 * GDB now has some support for using labels in the program's source in
3280 linespecs. For instance, you can use "advance label" to continue
3281 execution to a label.
3283 * GDB now has support for reading and writing a new .gdb_index
3284 section. This section holds a fast index of DWARF debugging
3285 information and can be used to greatly speed up GDB startup and
3286 operation. See the documentation for `save gdb-index' for details.
3288 * The "watch" command now accepts an optional "-location" argument.
3289 When used, this causes GDB to watch the memory referred to by the
3290 expression. Such a watchpoint is never deleted due to it going out
3293 * GDB now supports thread debugging of core dumps on GNU/Linux.
3295 GDB now activates thread debugging using the libthread_db library
3296 when debugging GNU/Linux core dumps, similarly to when debugging
3297 live processes. As a result, when debugging a core dump file, GDB
3298 is now able to display pthread_t ids of threads. For example, "info
3299 threads" shows the same output as when debugging the process when it
3300 was live. In earlier releases, you'd see something like this:
3303 * 1 LWP 6780 main () at main.c:10
3305 While now you see this:
3308 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3310 It is also now possible to inspect TLS variables when debugging core
3313 When debugging a core dump generated on a machine other than the one
3314 used to run GDB, you may need to point GDB at the correct
3315 libthread_db library with the "set libthread-db-search-path"
3316 command. See the user manual for more details on this command.
3318 * When natively debugging programs on PowerPC BookE processors running
3319 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3320 which stop execution of the inferior whenever it executes an instruction
3321 at any address within the specified range. See the "PowerPC Embedded"
3322 section in the user manual for more details.
3324 * New features in the GDB remote stub, GDBserver
3326 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3327 and i686 LynxOS (version 5.x).
3329 ** GDBserver is now supported on Blackfin Linux.
3331 * New native configurations
3333 ia64 HP-UX ia64-*-hpux*
3337 Analog Devices, Inc. Blackfin Processor bfin-*
3339 * Ada task switching is now supported on sparc-elf targets when
3340 debugging a program using the Ravenscar Profile. For more information,
3341 see the "Tasking Support when using the Ravenscar Profile" section
3342 in the GDB user manual.
3344 * Guile support was removed.
3346 * New features in the GNU simulator
3348 ** The --map-info flag lists all known core mappings.
3350 ** CFI flashes may be simulated via the "cfi" device.
3352 *** Changes in GDB 7.2
3354 * Shared library support for remote targets by default
3356 When GDB is configured for a generic, non-OS specific target, like
3357 for example, --target=arm-eabi or one of the many *-*-elf targets,
3358 GDB now queries remote stubs for loaded shared libraries using the
3359 `qXfer:libraries:read' packet. Previously, shared library support
3360 was always disabled for such configurations.
3364 ** Argument Dependent Lookup (ADL)
3366 In C++ ADL lookup directs function search to the namespaces of its
3367 arguments even if the namespace has not been imported.
3377 Here the compiler will search for `foo' in the namespace of 'b'
3378 and find A::foo. GDB now supports this. This construct is commonly
3379 used in the Standard Template Library for operators.
3381 ** Improved User Defined Operator Support
3383 In addition to member operators, GDB now supports lookup of operators
3384 defined in a namespace and imported with a `using' directive, operators
3385 defined in the global scope, operators imported implicitly from an
3386 anonymous namespace, and the ADL operators mentioned in the previous
3388 GDB now also supports proper overload resolution for all the previously
3389 mentioned flavors of operators.
3391 ** static const class members
3393 Printing of static const class members that are initialized in the
3394 class definition has been fixed.
3396 * Windows Thread Information Block access.
3398 On Windows targets, GDB now supports displaying the Windows Thread
3399 Information Block (TIB) structure. This structure is visible either
3400 by using the new command `info w32 thread-information-block' or, by
3401 dereferencing the new convenience variable named `$_tlb', a
3402 thread-specific pointer to the TIB. This feature is also supported
3403 when remote debugging using GDBserver.
3405 * Static tracepoints
3407 Static tracepoints are calls in the user program into a tracing
3408 library. One such library is a port of the LTTng kernel tracer to
3409 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3410 When debugging with GDBserver, GDB now supports combining the GDB
3411 tracepoint machinery with such libraries. For example: the user can
3412 use GDB to probe a static tracepoint marker (a call from the user
3413 program into the tracing library) with the new "strace" command (see
3414 "New commands" below). This creates a "static tracepoint" in the
3415 breakpoint list, that can be manipulated with the same feature set
3416 as fast and regular tracepoints. E.g., collect registers, local and
3417 global variables, collect trace state variables, and define
3418 tracepoint conditions. In addition, the user can collect extra
3419 static tracepoint marker specific data, by collecting the new
3420 $_sdata internal variable. When analyzing the trace buffer, you can
3421 inspect $_sdata like any other variable available to GDB. For more
3422 information, see the "Tracepoints" chapter in GDB user manual. New
3423 remote packets have been defined to support static tracepoints, see
3424 the "New remote packets" section below.
3426 * Better reconstruction of tracepoints after disconnected tracing
3428 GDB will attempt to download the original source form of tracepoint
3429 definitions when starting a trace run, and then will upload these
3430 upon reconnection to the target, resulting in a more accurate
3431 reconstruction of the tracepoints that are in use on the target.
3435 You can now exercise direct control over the ways that GDB can
3436 affect your program. For instance, you can disallow the setting of
3437 breakpoints, so that the program can run continuously (assuming
3438 non-stop mode). In addition, the "observer" variable is available
3439 to switch all of the different controls; in observer mode, GDB
3440 cannot affect the target's behavior at all, which is useful for
3441 tasks like diagnosing live systems in the field.
3443 * The new convenience variable $_thread holds the number of the
3446 * New remote packets
3450 Return the address of the Windows Thread Information Block of a given thread.
3454 In response to several of the tracepoint packets, the target may now
3455 also respond with a number of intermediate `qRelocInsn' request
3456 packets before the final result packet, to have GDB handle
3457 relocating an instruction to execute at a different address. This
3458 is particularly useful for stubs that support fast tracepoints. GDB
3459 reports support for this feature in the qSupported packet.
3463 List static tracepoint markers in the target program.
3467 List static tracepoint markers at a given address in the target
3470 qXfer:statictrace:read
3472 Read the static trace data collected (by a `collect $_sdata'
3473 tracepoint action). The remote stub reports support for this packet
3474 to gdb's qSupported query.
3478 Send the current settings of GDB's permission flags.
3482 Send part of the source (textual) form of a tracepoint definition,
3483 which includes location, conditional, and action list.
3485 * The source command now accepts a -s option to force searching for the
3486 script in the source search path even if the script name specifies
3489 * New features in the GDB remote stub, GDBserver
3491 - GDBserver now support tracepoints (including fast tracepoints, and
3492 static tracepoints). The feature is currently supported by the
3493 i386-linux and amd64-linux builds. See the "Tracepoints support
3494 in gdbserver" section in the manual for more information.
3496 GDBserver JIT compiles the tracepoint's conditional agent
3497 expression bytecode into native code whenever possible for low
3498 overhead dynamic tracepoints conditionals. For such tracepoints,
3499 an expression that examines program state is evaluated when the
3500 tracepoint is reached, in order to determine whether to capture
3501 trace data. If the condition is simple and false, processing the
3502 tracepoint finishes very quickly and no data is gathered.
3504 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3505 for static tracepoints support.
3507 - GDBserver now supports x86_64 Windows 64-bit debugging.
3509 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3510 it understands register description.
3512 * The --batch flag now disables pagination and queries.
3514 * X86 general purpose registers
3516 GDB now supports reading/writing byte, word and double-word x86
3517 general purpose registers directly. This means you can use, say,
3518 $ah or $ax to refer, respectively, to the byte register AH and
3519 16-bit word register AX that are actually portions of the 32-bit
3520 register EAX or 64-bit register RAX.
3522 * The `commands' command now accepts a range of breakpoints to modify.
3523 A plain `commands' following a command that creates multiple
3524 breakpoints affects all the breakpoints set by that command. This
3525 applies to breakpoints set by `rbreak', and also applies when a
3526 single `break' command creates multiple breakpoints (e.g.,
3527 breakpoints on overloaded c++ functions).
3529 * The `rbreak' command now accepts a filename specification as part of
3530 its argument, limiting the functions selected by the regex to those
3531 in the specified file.
3533 * Support for remote debugging Windows and SymbianOS shared libraries
3534 from Unix hosts has been improved. Non Windows GDB builds now can
3535 understand target reported file names that follow MS-DOS based file
3536 system semantics, such as file names that include drive letters and
3537 use the backslash character as directory separator. This makes it
3538 possible to transparently use the "set sysroot" and "set
3539 solib-search-path" on Unix hosts to point as host copies of the
3540 target's shared libraries. See the new command "set
3541 target-file-system-kind" described below, and the "Commands to
3542 specify files" section in the user manual for more information.
3546 eval template, expressions...
3547 Convert the values of one or more expressions under the control
3548 of the string template to a command line, and call it.
3550 set target-file-system-kind unix|dos-based|auto
3551 show target-file-system-kind
3552 Set or show the assumed file system kind for target reported file
3555 save breakpoints <filename>
3556 Save all current breakpoint definitions to a file suitable for use
3557 in a later debugging session. To read the saved breakpoint
3558 definitions, use the `source' command.
3560 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3563 info static-tracepoint-markers
3564 Display information about static tracepoint markers in the target.
3566 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3567 Define a static tracepoint by probing a marker at the given
3568 function, line, address, or marker ID.
3572 Enable and disable observer mode.
3574 set may-write-registers on|off
3575 set may-write-memory on|off
3576 set may-insert-breakpoints on|off
3577 set may-insert-tracepoints on|off
3578 set may-insert-fast-tracepoints on|off
3579 set may-interrupt on|off
3580 Set individual permissions for GDB effects on the target. Note that
3581 some of these settings can have undesirable or surprising
3582 consequences, particularly when changed in the middle of a session.
3583 For instance, disabling the writing of memory can prevent
3584 breakpoints from being inserted, cause single-stepping to fail, or
3585 even crash your program, if you disable after breakpoints have been
3586 inserted. However, GDB should not crash.
3588 set record memory-query on|off
3589 show record memory-query
3590 Control whether to stop the inferior if memory changes caused
3591 by an instruction cannot be recorded.
3596 The disassemble command now supports "start,+length" form of two arguments.
3600 ** GDB now provides a new directory location, called the python directory,
3601 where Python scripts written for GDB can be installed. The location
3602 of that directory is <data-directory>/python, where <data-directory>
3603 is the GDB data directory. For more details, see section `Scripting
3604 GDB using Python' in the manual.
3606 ** The GDB Python API now has access to breakpoints, symbols, symbol
3607 tables, program spaces, inferiors, threads and frame's code blocks.
3608 Additionally, GDB Parameters can now be created from the API, and
3609 manipulated via set/show in the CLI.
3611 ** New functions gdb.target_charset, gdb.target_wide_charset,
3612 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3614 ** New exception gdb.GdbError.
3616 ** Pretty-printers are now also looked up in the current program space.
3618 ** Pretty-printers can now be individually enabled and disabled.
3620 ** GDB now looks for names of Python scripts to auto-load in a
3621 special section named `.debug_gdb_scripts', in addition to looking
3622 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3624 * Tracepoint actions were unified with breakpoint commands. In particular,
3625 there are no longer differences in "info break" output for breakpoints and
3626 tracepoints and the "commands" command can be used for both tracepoints and
3627 regular breakpoints.
3631 ARM Symbian arm*-*-symbianelf*
3633 * D language support.
3634 GDB now supports debugging programs written in the D programming
3637 * GDB now supports the extended ptrace interface for PowerPC which is
3638 available since Linux kernel version 2.6.34. This automatically enables
3639 any hardware breakpoints and additional hardware watchpoints available in
3640 the processor. The old ptrace interface exposes just one hardware
3641 watchpoint and no hardware breakpoints.
3643 * GDB is now able to use the Data Value Compare (DVC) register available on
3644 embedded PowerPC processors to implement in hardware simple watchpoint
3645 conditions of the form:
3647 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3649 This works in native GDB running on Linux kernels with the extended ptrace
3650 interface mentioned above.
3652 *** Changes in GDB 7.1
3656 ** Namespace Support
3658 GDB now supports importing of namespaces in C++. This enables the
3659 user to inspect variables from imported namespaces. Support for
3660 namepace aliasing has also been added. So, if a namespace is
3661 aliased in the current scope (e.g. namepace C=A; ) the user can
3662 print variables using the alias (e.g. (gdb) print C::x).
3666 All known bugs relating to the printing of virtual base class were
3667 fixed. It is now possible to call overloaded static methods using a
3672 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3673 and reinterpret_cast<> are now handled by the C++ expression parser.
3677 Xilinx MicroBlaze microblaze-*-*
3682 Xilinx MicroBlaze microblaze
3685 * Multi-program debugging.
3687 GDB now has support for multi-program (a.k.a. multi-executable or
3688 multi-exec) debugging. This allows for debugging multiple inferiors
3689 simultaneously each running a different program under the same GDB
3690 session. See "Debugging Multiple Inferiors and Programs" in the
3691 manual for more information. This implied some user visible changes
3692 in the multi-inferior support. For example, "info inferiors" now
3693 lists inferiors that are not running yet or that have exited
3694 already. See also "New commands" and "New options" below.
3696 * New tracing features
3698 GDB's tracepoint facility now includes several new features:
3700 ** Trace state variables
3702 GDB tracepoints now include support for trace state variables, which
3703 are variables managed by the target agent during a tracing
3704 experiment. They are useful for tracepoints that trigger each
3705 other, so for instance one tracepoint can count hits in a variable,
3706 and then a second tracepoint has a condition that is true when the
3707 count reaches a particular value. Trace state variables share the
3708 $-syntax of GDB convenience variables, and can appear in both
3709 tracepoint actions and condition expressions. Use the "tvariable"
3710 command to create, and "info tvariables" to view; see "Trace State
3711 Variables" in the manual for more detail.
3715 GDB now includes an option for defining fast tracepoints, which
3716 targets may implement more efficiently, such as by installing a jump
3717 into the target agent rather than a trap instruction. The resulting
3718 speedup can be by two orders of magnitude or more, although the
3719 tradeoff is that some program locations on some target architectures
3720 might not allow fast tracepoint installation, for instance if the
3721 instruction to be replaced is shorter than the jump. To request a
3722 fast tracepoint, use the "ftrace" command, with syntax identical to
3723 the regular trace command.
3725 ** Disconnected tracing
3727 It is now possible to detach GDB from the target while it is running
3728 a trace experiment, then reconnect later to see how the experiment
3729 is going. In addition, a new variable disconnected-tracing lets you
3730 tell the target agent whether to continue running a trace if the
3731 connection is lost unexpectedly.
3735 GDB now has the ability to save the trace buffer into a file, and
3736 then use that file as a target, similarly to you can do with
3737 corefiles. You can select trace frames, print data that was
3738 collected in them, and use tstatus to display the state of the
3739 tracing run at the moment that it was saved. To create a trace
3740 file, use "tsave <filename>", and to use it, do "target tfile
3743 ** Circular trace buffer
3745 You can ask the target agent to handle the trace buffer as a
3746 circular buffer, discarding the oldest trace frames to make room for
3747 newer ones, by setting circular-trace-buffer to on. This feature may
3748 not be available for all target agents.
3753 The disassemble command, when invoked with two arguments, now requires
3754 the arguments to be comma-separated.
3757 The info variables command now displays variable definitions. Files
3758 which only declare a variable are not shown.
3761 The source command is now capable of sourcing Python scripts.
3762 This feature is dependent on the debugger being build with Python
3765 Related to this enhancement is also the introduction of a new command
3766 "set script-extension" (see below).
3768 * New commands (for set/show, see "New options" below)
3770 record save [<FILENAME>]
3771 Save a file (in core file format) containing the process record
3772 execution log for replay debugging at a later time.
3774 record restore <FILENAME>
3775 Restore the process record execution log that was saved at an
3776 earlier time, for replay debugging.
3778 add-inferior [-copies <N>] [-exec <FILENAME>]
3781 clone-inferior [-copies <N>] [ID]
3782 Make a new inferior ready to execute the same program another
3783 inferior has loaded.
3788 maint info program-spaces
3789 List the program spaces loaded into GDB.
3791 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3792 show remote interrupt-sequence
3793 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3794 as the sequence to the remote target in order to interrupt the execution.
3795 Ctrl-C is a default. Some system prefers BREAK which is high level of
3796 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3797 Magic SysRq g. It is BREAK signal and character 'g'.
3799 set remote interrupt-on-connect [on | off]
3800 show remote interrupt-on-connect
3801 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3802 remote target when gdb connects to it. This is needed when you debug
3805 set remotebreak [on | off]
3807 Deprecated. Use "set/show remote interrupt-sequence" instead.
3809 tvariable $NAME [ = EXP ]
3810 Create or modify a trace state variable.
3813 List trace state variables and their values.
3815 delete tvariable $NAME ...
3816 Delete one or more trace state variables.
3819 Evaluate the given expressions without collecting anything into the
3820 trace buffer. (Valid in tracepoint actions only.)
3822 ftrace FN / FILE:LINE / *ADDR
3823 Define a fast tracepoint at the given function, line, or address.
3825 * New expression syntax
3827 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3828 GDB now parses 0b101010 identically with 42.
3832 set follow-exec-mode new|same
3833 show follow-exec-mode
3834 Control whether GDB reuses the same inferior across an exec call or
3835 creates a new one. This is useful to be able to restart the old
3836 executable after the inferior having done an exec call.
3838 set default-collect EXPR, ...
3839 show default-collect
3840 Define a list of expressions to be collected at each tracepoint.
3841 This is a useful way to ensure essential items are not overlooked,
3842 such as registers or a critical global variable.
3844 set disconnected-tracing
3845 show disconnected-tracing
3846 If set to 1, the target is instructed to continue tracing if it
3847 loses its connection to GDB. If 0, the target is to stop tracing
3850 set circular-trace-buffer
3851 show circular-trace-buffer
3852 If set to on, the target is instructed to use a circular trace buffer
3853 and discard the oldest trace frames instead of stopping the trace due
3854 to a full trace buffer. If set to off, the trace stops when the buffer
3855 fills up. Some targets may not support this.
3857 set script-extension off|soft|strict
3858 show script-extension
3859 If set to "off", the debugger does not perform any script language
3860 recognition, and all sourced files are assumed to be GDB scripts.
3861 If set to "soft" (the default), files are sourced according to
3862 filename extension, falling back to GDB scripts if the first
3864 If set to "strict", files are sourced according to filename extension.
3866 set ada trust-PAD-over-XVS on|off
3867 show ada trust-PAD-over-XVS
3868 If off, activate a workaround against a bug in the debugging information
3869 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3870 the GCC sources for more information about the GNAT encoding and
3871 PAD types in particular). It is always safe to set this option to
3872 off, but this introduces a slight performance penalty. The default
3875 * Python API Improvements
3877 ** GDB provides the new class gdb.LazyString. This is useful in
3878 some pretty-printing cases. The new method gdb.Value.lazy_string
3879 provides a simple way to create objects of this type.
3881 ** The fields returned by gdb.Type.fields now have an
3882 `is_base_class' attribute.
3884 ** The new method gdb.Type.range returns the range of an array type.
3886 ** The new method gdb.parse_and_eval can be used to parse and
3887 evaluate an expression.
3889 * New remote packets
3892 Define a trace state variable.
3895 Get the current value of a trace state variable.
3898 Set desired tracing behavior upon disconnection.
3901 Set the trace buffer to be linear or circular.
3904 Get data about the tracepoints currently in use.
3908 Process record now works correctly with hardware watchpoints.
3910 Multiple bug fixes have been made to the mips-irix port, making it
3911 much more reliable. In particular:
3912 - Debugging threaded applications is now possible again. Previously,
3913 GDB would hang while starting the program, or while waiting for
3914 the program to stop at a breakpoint.
3915 - Attaching to a running process no longer hangs.
3916 - An error occurring while loading a core file has been fixed.
3917 - Changing the value of the PC register now works again. This fixes
3918 problems observed when using the "jump" command, or when calling
3919 a function from GDB, or even when assigning a new value to $pc.
3920 - With the "finish" and "return" commands, the return value for functions
3921 returning a small array is now correctly printed.
3922 - It is now possible to break on shared library code which gets executed
3923 during a shared library init phase (code executed while executing
3924 their .init section). Previously, the breakpoint would have no effect.
3925 - GDB is now able to backtrace through the signal handler for
3926 non-threaded programs.
3928 PIE (Position Independent Executable) programs debugging is now supported.
3929 This includes debugging execution of PIC (Position Independent Code) shared
3930 libraries although for that, it should be possible to run such libraries as an
3933 *** Changes in GDB 7.0
3935 * GDB now has an interface for JIT compilation. Applications that
3936 dynamically generate code can create symbol files in memory and register
3937 them with GDB. For users, the feature should work transparently, and
3938 for JIT developers, the interface is documented in the GDB manual in the
3939 "JIT Compilation Interface" chapter.
3941 * Tracepoints may now be conditional. The syntax is as for
3942 breakpoints; either an "if" clause appended to the "trace" command,
3943 or the "condition" command is available. GDB sends the condition to
3944 the target for evaluation using the same bytecode format as is used
3945 for tracepoint actions.
3947 * The disassemble command now supports: an optional /r modifier, print the
3948 raw instructions in hex as well as in symbolic form, and an optional /m
3949 modifier to print mixed source+assembly.
3951 * Process record and replay
3953 In a architecture environment that supports ``process record and
3954 replay'', ``process record and replay'' target can record a log of
3955 the process execution, and replay it with both forward and reverse
3958 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3959 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3960 set execution-direction {forward|reverse}, for targets that support
3963 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3964 feature is available with a native GDB running on kernel version
3967 * GDB now has support for multi-byte and wide character sets on the
3968 target. Strings whose character type is wchar_t, char16_t, or
3969 char32_t are now correctly printed. GDB supports wide- and unicode-
3970 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3971 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3972 `printf'. This feature requires iconv to work properly; if your
3973 system does not have a working iconv, GDB can use GNU libiconv. See
3974 the installation instructions for more information.
3976 * GDB now supports automatic retrieval of shared library files from
3977 remote targets. To use this feature, specify a system root that begins
3978 with the `remote:' prefix, either via the `set sysroot' command or via
3979 the `--with-sysroot' configure-time option.
3981 * "info sharedlibrary" now takes an optional regex of libraries to show,
3982 and it now reports if a shared library has no debugging information.
3984 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3985 now complete on file names.
3987 * When completing in expressions, gdb will attempt to limit
3988 completions to allowable structure or union fields, where appropriate.
3989 For instance, consider:
3991 # struct example { int f1; double f2; };
3992 # struct example variable;
3995 If the user types TAB at the end of this command line, the available
3996 completions will be "f1" and "f2".
3998 * Inlined functions are now supported. They show up in backtraces, and
3999 the "step", "next", and "finish" commands handle them automatically.
4001 * GDB now supports the token-splicing (##) and stringification (#)
4002 operators when expanding macros. It also supports variable-arity
4005 * GDB now supports inspecting extra signal information, exported by
4006 the new $_siginfo convenience variable. The feature is currently
4007 implemented on linux ARM, i386 and amd64.
4009 * GDB can now display the VFP floating point registers and NEON vector
4010 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4011 can provide these registers (requires Linux 2.6.30 or later). Remote
4012 and simulator targets may also provide them.
4014 * New remote packets
4017 Search memory for a sequence of bytes.
4020 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4021 operation over reliable transport links. Use of this packet is
4022 controlled by the `set remote noack-packet' command.
4025 Kill the process with the specified process ID. Use this in preference
4026 to `k' when multiprocess protocol extensions are supported.
4029 Obtains additional operating system information
4033 Read or write additional signal information.
4035 * Removed remote protocol undocumented extension
4037 An undocumented extension to the remote protocol's `S' stop reply
4038 packet that permited the stub to pass a process id was removed.
4039 Remote servers should use the `T' stop reply packet instead.
4041 * GDB now supports multiple function calling conventions according to the
4042 DWARF-2 DW_AT_calling_convention function attribute.
4044 * The SH target utilizes the aforementioned change to distinguish between gcc
4045 and Renesas calling convention. It also adds the new CLI commands
4046 `set/show sh calling-convention'.
4048 * GDB can now read compressed debug sections, as produced by GNU gold
4049 with the --compress-debug-sections=zlib flag.
4051 * 64-bit core files are now supported on AIX.
4053 * Thread switching is now supported on Tru64.
4055 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4056 which will be allocated using malloc later in program execution.
4058 * The qXfer:libraries:read remote procotol packet now allows passing a
4059 list of section offsets.
4061 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4062 conditions handling signals delivered during attach or thread creation
4063 have also been fixed.
4065 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4066 From the user's standpoint, all unqualified instances of True and False
4067 are treated as the standard definitions, regardless of context.
4069 * GDB now parses C++ symbol and type names more flexibly. For
4072 template<typename T> class C { };
4075 GDB will now correctly handle all of:
4077 ptype C<char const *>
4078 ptype C<char const*>
4079 ptype C<const char *>
4080 ptype C<const char*>
4082 * New features in the GDB remote stub, gdbserver
4084 - The "--wrapper" command-line argument tells gdbserver to use a
4085 wrapper program to launch programs for debugging.
4087 - On PowerPC and S/390 targets, it is now possible to use a single
4088 gdbserver executable to debug both 32-bit and 64-bit programs.
4089 (This requires gdbserver itself to be built as a 64-bit executable.)
4091 - gdbserver uses the new noack protocol mode for TCP connections to
4092 reduce communications latency, if also supported and enabled in GDB.
4094 - Support for the sparc64-linux-gnu target is now included in
4097 - The amd64-linux build of gdbserver now supports debugging both
4098 32-bit and 64-bit programs.
4100 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4101 now support hardware watchpoints, and will use them automatically
4106 GDB now has support for scripting using Python. Whether this is
4107 available is determined at configure time.
4109 New GDB commands can now be written in Python.
4111 * Ada tasking support
4113 Ada tasks can now be inspected in GDB. The following commands have
4117 Print the list of Ada tasks.
4119 Print detailed information about task number N.
4121 Print the task number of the current task.
4123 Switch the context of debugging to task number N.
4125 * Support for user-defined prefixed commands. The "define" command can
4126 add new commands to existing prefixes, e.g. "target".
4128 * Multi-inferior, multi-process debugging.
4130 GDB now has generalized support for multi-inferior debugging. See
4131 "Debugging Multiple Inferiors" in the manual for more information.
4132 Although availability still depends on target support, the command
4133 set is more uniform now. The GNU/Linux specific multi-forks support
4134 has been migrated to this new framework. This implied some user
4135 visible changes; see "New commands" and also "Removed commands"
4138 * Target descriptions can now describe the target OS ABI. See the
4139 "Target Description Format" section in the user manual for more
4142 * Target descriptions can now describe "compatible" architectures
4143 to indicate that the target can execute applications for a different
4144 architecture in addition to those for the main target architecture.
4145 See the "Target Description Format" section in the user manual for
4148 * Multi-architecture debugging.
4150 GDB now includes general supports for debugging applications on
4151 hybrid systems that use more than one single processor architecture
4152 at the same time. Each such hybrid architecture still requires
4153 specific support to be added. The only hybrid architecture supported
4154 in this version of GDB is the Cell Broadband Engine.
4156 * GDB now supports integrated debugging of Cell/B.E. applications that
4157 use both the PPU and SPU architectures. To enable support for hybrid
4158 Cell/B.E. debugging, you need to configure GDB to support both the
4159 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4160 --enable-targets configure option.
4162 * Non-stop mode debugging.
4164 For some targets, GDB now supports an optional mode of operation in
4165 which you can examine stopped threads while other threads continue
4166 to execute freely. This is referred to as non-stop mode, with the
4167 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4168 section in the user manual for more information.
4170 To be able to support remote non-stop debugging, a remote stub needs
4171 to implement the non-stop mode remote protocol extensions, as
4172 described in the "Remote Non-Stop" section of the user manual. The
4173 GDB remote stub, gdbserver, has been adjusted to support these
4174 extensions on linux targets.
4176 * New commands (for set/show, see "New options" below)
4178 catch syscall [NAME(S) | NUMBER(S)]
4179 Catch system calls. Arguments, which should be names of system
4180 calls or their numbers, mean catch only those syscalls. Without
4181 arguments, every syscall will be caught. When the inferior issues
4182 any of the specified syscalls, GDB will stop and announce the system
4183 call, both when it is called and when its call returns. This
4184 feature is currently available with a native GDB running on the
4185 Linux Kernel, under the following architectures: x86, x86_64,
4186 PowerPC and PowerPC64.
4188 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4190 Search memory for a sequence of bytes.
4192 maint set python print-stack
4193 maint show python print-stack
4194 Show a stack trace when an error is encountered in a Python script.
4197 Invoke CODE by passing it to the Python interpreter.
4202 These allow macros to be defined, undefined, and listed
4206 Show operating system information about processes.
4209 List the inferiors currently under GDB's control.
4212 Switch focus to inferior number NUM.
4215 Detach from inferior number NUM.
4218 Kill inferior number NUM.
4222 set spu stop-on-load
4223 show spu stop-on-load
4224 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4226 set spu auto-flush-cache
4227 show spu auto-flush-cache
4228 Control whether to automatically flush the software-managed cache
4229 during Cell/B.E. debugging.
4231 set sh calling-convention
4232 show sh calling-convention
4233 Control the calling convention used when calling SH target functions.
4236 show debug timestamp
4237 Control display of timestamps with GDB debugging output.
4239 set disassemble-next-line
4240 show disassemble-next-line
4241 Control display of disassembled source lines or instructions when
4244 set remote noack-packet
4245 show remote noack-packet
4246 Set/show the use of remote protocol QStartNoAckMode packet. See above
4247 under "New remote packets."
4249 set remote query-attached-packet
4250 show remote query-attached-packet
4251 Control use of remote protocol `qAttached' (query-attached) packet.
4253 set remote read-siginfo-object
4254 show remote read-siginfo-object
4255 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4258 set remote write-siginfo-object
4259 show remote write-siginfo-object
4260 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4263 set remote reverse-continue
4264 show remote reverse-continue
4265 Control use of remote protocol 'bc' (reverse-continue) packet.
4267 set remote reverse-step
4268 show remote reverse-step
4269 Control use of remote protocol 'bs' (reverse-step) packet.
4271 set displaced-stepping
4272 show displaced-stepping
4273 Control displaced stepping mode. Displaced stepping is a way to
4274 single-step over breakpoints without removing them from the debuggee.
4275 Also known as "out-of-line single-stepping".
4278 show debug displaced
4279 Control display of debugging info for displaced stepping.
4281 maint set internal-error
4282 maint show internal-error
4283 Control what GDB does when an internal error is detected.
4285 maint set internal-warning
4286 maint show internal-warning
4287 Control what GDB does when an internal warning is detected.
4292 Use a wrapper program to launch programs for debugging.
4294 set multiple-symbols (all|ask|cancel)
4295 show multiple-symbols
4296 The value of this variable can be changed to adjust the debugger behavior
4297 when an expression or a breakpoint location contains an ambiguous symbol
4298 name (an overloaded function name, for instance).
4300 set breakpoint always-inserted
4301 show breakpoint always-inserted
4302 Keep breakpoints always inserted in the target, as opposed to inserting
4303 them when resuming the target, and removing them when the target stops.
4304 This option can improve debugger performance on slow remote targets.
4306 set arm fallback-mode (arm|thumb|auto)
4307 show arm fallback-mode
4308 set arm force-mode (arm|thumb|auto)
4310 These commands control how ARM GDB determines whether instructions
4311 are ARM or Thumb. The default for both settings is auto, which uses
4312 the current CPSR value for instructions without symbols; previous
4313 versions of GDB behaved as if "set arm fallback-mode arm".
4315 set disable-randomization
4316 show disable-randomization
4317 Standalone programs run with the virtual address space randomization enabled
4318 by default on some platforms. This option keeps the addresses stable across
4319 multiple debugging sessions.
4323 Control whether other threads are stopped or not when some thread hits
4328 Requests that asynchronous execution is enabled in the target, if available.
4329 In this case, it's possible to resume target in the background, and interact
4330 with GDB while the target is running. "show target-async" displays the
4331 current state of asynchronous execution of the target.
4333 set target-wide-charset
4334 show target-wide-charset
4335 The target-wide-charset is the name of the character set that GDB
4336 uses when printing characters whose type is wchar_t.
4338 set tcp auto-retry (on|off)
4340 set tcp connect-timeout
4341 show tcp connect-timeout
4342 These commands allow GDB to retry failed TCP connections to a remote stub
4343 with a specified timeout period; this is useful if the stub is launched
4344 in parallel with GDB but may not be ready to accept connections immediately.
4346 set libthread-db-search-path
4347 show libthread-db-search-path
4348 Control list of directories which GDB will search for appropriate
4351 set schedule-multiple (on|off)
4352 show schedule-multiple
4353 Allow GDB to resume all threads of all processes or only threads of
4354 the current process.
4358 Use more aggressive caching for accesses to the stack. This improves
4359 performance of remote debugging (particularly backtraces) without
4360 affecting correctness.
4362 set interactive-mode (on|off|auto)
4363 show interactive-mode
4364 Control whether GDB runs in interactive mode (on) or not (off).
4365 When in interactive mode, GDB waits for the user to answer all
4366 queries. Otherwise, GDB does not wait and assumes the default
4367 answer. When set to auto (the default), GDB determines which
4368 mode to use based on the stdin settings.
4373 For program forks, this is replaced by the new more generic `info
4374 inferiors' command. To list checkpoints, you can still use the
4375 `info checkpoints' command, which was an alias for the `info forks'
4379 Replaced by the new `inferior' command. To switch between
4380 checkpoints, you can still use the `restart' command, which was an
4381 alias for the `fork' command.
4384 This is removed, since some targets don't have a notion of
4385 processes. To switch between processes, you can still use the
4386 `inferior' command using GDB's own inferior number.
4389 For program forks, this is replaced by the new more generic `kill
4390 inferior' command. To delete a checkpoint, you can still use the
4391 `delete checkpoint' command, which was an alias for the `delete
4395 For program forks, this is replaced by the new more generic `detach
4396 inferior' command. To detach a checkpoint, you can still use the
4397 `detach checkpoint' command, which was an alias for the `detach
4400 * New native configurations
4402 x86/x86_64 Darwin i[34567]86-*-darwin*
4404 x86_64 MinGW x86_64-*-mingw*
4408 Lattice Mico32 lm32-*
4409 x86 DICOS i[34567]86-*-dicos*
4410 x86_64 DICOS x86_64-*-dicos*
4413 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4414 (mingw32ce) debugging.
4420 These commands were actually not implemented on any target.
4422 *** Changes in GDB 6.8
4424 * New native configurations
4426 NetBSD/hppa hppa*-*netbsd*
4427 Xtensa GNU/Linux xtensa*-*-linux*
4431 NetBSD/hppa hppa*-*-netbsd*
4432 Xtensa GNU/Lunux xtensa*-*-linux*
4434 * Change in command line behavior -- corefiles vs. process ids.
4436 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4437 attaching to process NUMBER fails, GDB no longer attempts to open a
4438 core file named NUMBER. Attaching to a program using the -c option
4439 is no longer supported. Instead, use the '-p' or '--pid' options.
4441 * GDB can now be built as a native debugger for debugging Windows x86
4442 (mingw32) Portable Executable (PE) programs.
4444 * Pending breakpoints no longer change their number when their address
4447 * GDB now supports breakpoints with multiple locations,
4448 including breakpoints on C++ constructors, inside C++ templates,
4449 and in inlined functions.
4451 * GDB's ability to debug optimized code has been improved. GDB more
4452 accurately identifies function bodies and lexical blocks that occupy
4453 more than one contiguous range of addresses.
4455 * Target descriptions can now describe registers for PowerPC.
4457 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4458 registers on PowerPC targets.
4460 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4461 targets even when the libthread_db library is not available.
4463 * The GDB remote stub, gdbserver, now supports the new file transfer
4464 commands (remote put, remote get, and remote delete).
4466 * The GDB remote stub, gdbserver, now supports run and attach in
4467 extended-remote mode.
4469 * hppa*64*-*-hpux11* target broken
4470 The debugger is unable to start a program and fails with the following
4471 error: "Error trying to get information about dynamic linker".
4472 The gdb-6.7 release is also affected.
4474 * GDB now supports the --enable-targets= configure option to allow
4475 building a single GDB executable that supports multiple remote
4476 target architectures.
4478 * GDB now supports debugging C and C++ programs which use the
4479 Decimal Floating Point extension. In addition, the PowerPC target
4480 now has a set of pseudo-registers to inspect decimal float values
4481 stored in two consecutive float registers.
4483 * The -break-insert MI command can optionally create pending
4486 * Improved support for debugging Ada
4487 Many improvements to the Ada language support have been made. These
4489 - Better support for Ada2005 interface types
4490 - Improved handling of arrays and slices in general
4491 - Better support for Taft-amendment types
4492 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4494 - Improved command completion in Ada
4497 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4502 set print frame-arguments (all|scalars|none)
4503 show print frame-arguments
4504 The value of this variable can be changed to control which argument
4505 values should be printed by the debugger when displaying a frame.
4510 Transfer files to and from a remote target, and delete remote files.
4517 Transfer files to and from a remote target, and delete remote files.
4519 * New remote packets
4526 Open, close, read, write, and delete files on the remote system.
4529 Attach to an existing process on the remote system, in extended-remote
4533 Run a new process on the remote system, in extended-remote mode.
4535 *** Changes in GDB 6.7
4537 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4538 bfd, libiberty and opcodes, as revealed by static analysis donated by
4539 Coverity, Inc. (http://scan.coverity.com).
4541 * When looking up multiply-defined global symbols, GDB will now prefer the
4542 symbol definition in the current shared library if it was built using the
4543 -Bsymbolic linker option.
4545 * When the Text User Interface (TUI) is not configured, GDB will now
4546 recognize the -tui command-line option and print a message that the TUI
4549 * The GDB remote stub, gdbserver, now has lower overhead for high
4550 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4552 * GDB for MIPS targets now autodetects whether a remote target provides
4553 32-bit or 64-bit register values.
4555 * Support for C++ member pointers has been improved.
4557 * GDB now understands XML target descriptions, which specify the
4558 target's overall architecture. GDB can read a description from
4559 a local file or over the remote serial protocol.
4561 * Vectors of single-byte data use a new integer type which is not
4562 automatically displayed as character or string data.
4564 * The /s format now works with the print command. It displays
4565 arrays of single-byte integers and pointers to single-byte integers
4568 * Target descriptions can now describe target-specific registers,
4569 for architectures which have implemented the support (currently
4570 only ARM, M68K, and MIPS).
4572 * GDB and the GDB remote stub, gdbserver, now support the XScale
4575 * The GDB remote stub, gdbserver, has been updated to support
4576 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4577 has been rewritten to use the standard GDB remote protocol.
4579 * GDB can now step into C++ functions which are called through thunks.
4581 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4583 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4584 layout. It also supports a TextSeg= and DataSeg= response when only
4585 segment base addresses (rather than offsets) are available.
4587 * The /i format now outputs any trailing branch delay slot instructions
4588 immediately following the last instruction within the count specified.
4590 * The GDB remote protocol "T" stop reply packet now supports a
4591 "library" response. Combined with the new "qXfer:libraries:read"
4592 packet, this response allows GDB to debug shared libraries on targets
4593 where the operating system manages the list of loaded libraries (e.g.
4594 Windows and SymbianOS).
4596 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4597 (DLLs) on Windows and Windows CE targets.
4599 * GDB now supports a faster verification that a .debug file matches its binary
4600 according to its build-id signature, if the signature is present.
4606 Enable or disable hardware flow control (RTS/CTS) on the serial port
4607 when debugging using remote targets.
4609 set mem inaccessible-by-default
4610 show mem inaccessible-by-default
4611 If the target supplies a memory map, for instance via the remote
4612 protocol's "qXfer:memory-map:read" packet, setting this variable
4613 prevents GDB from accessing memory outside the memory map. This
4614 is useful for targets with memory mapped registers or which react
4615 badly to accesses of unmapped address space.
4617 set breakpoint auto-hw
4618 show breakpoint auto-hw
4619 If the target supplies a memory map, for instance via the remote
4620 protocol's "qXfer:memory-map:read" packet, setting this variable
4621 lets GDB use hardware breakpoints automatically for memory regions
4622 where it can not use software breakpoints. This covers both the
4623 "break" command and internal breakpoints used for other commands
4624 including "next" and "finish".
4627 catch exception unhandled
4628 Stop the program execution when Ada exceptions are raised.
4631 Stop the program execution when an Ada assertion failed.
4635 Set an alternate system root for target files. This is a more
4636 general version of "set solib-absolute-prefix", which is now
4637 an alias to "set sysroot".
4640 Provide extended SPU facility status information. This set of
4641 commands is available only when debugging the Cell/B.E. SPU
4644 * New native configurations
4646 OpenBSD/sh sh*-*openbsd*
4649 unset tdesc filename
4651 Use the specified local file as an XML target description, and do
4652 not query the target for its built-in description.
4656 OpenBSD/sh sh*-*-openbsd*
4657 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4658 Toshiba Media Processor mep-elf
4660 * New remote packets
4663 Ignore the specified signals; pass them directly to the debugged program
4664 without stopping other threads or reporting them to GDB.
4666 qXfer:features:read:
4667 Read an XML target description from the target, which describes its
4672 Read or write contents of an spufs file on the target system. These
4673 packets are available only on the Cell/B.E. SPU architecture.
4675 qXfer:libraries:read:
4676 Report the loaded shared libraries. Combined with new "T" packet
4677 response, this packet allows GDB to debug shared libraries on
4678 targets where the operating system manages the list of loaded
4679 libraries (e.g. Windows and SymbianOS).
4683 Support for these obsolete configurations has been removed.
4691 i[34567]86-*-lynxos*
4692 i[34567]86-*-netware*
4693 i[34567]86-*-sco3.2v5*
4694 i[34567]86-*-sco3.2v4*
4696 i[34567]86-*-sysv4.2*
4699 i[34567]86-*-unixware2*
4700 i[34567]86-*-unixware*
4709 * Other removed features
4716 Various m68k-only ROM monitors.
4723 Various Renesas ROM monitors and debugging interfaces for SH and
4728 Support for a Macraigor serial interface to on-chip debugging.
4729 GDB does not directly support the newer parallel or USB
4734 A debug information format. The predecessor to DWARF 2 and
4735 DWARF 3, which are still supported.
4737 Support for the HP aCC compiler on HP-UX/PA-RISC
4739 SOM-encapsulated symbolic debugging information, automatic
4740 invocation of pxdb, and the aCC custom C++ ABI. This does not
4741 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4742 with aCC can still be debugged on an assembly level.
4744 MIPS ".pdr" sections
4746 A MIPS-specific format used to describe stack frame layout
4747 in debugging information.
4751 GDB could work with an older version of Guile to debug
4752 the interpreter and Scheme programs running in it.
4754 set mips stack-arg-size
4755 set mips saved-gpreg-size
4757 Use "set mips abi" to control parameter passing for MIPS.
4759 *** Changes in GDB 6.6
4764 Cell Broadband Engine SPU spu-elf
4766 * GDB can now be configured as a cross-debugger targeting native Windows
4767 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4768 running on a Windows system over TCP/IP to debug Windows programs.
4770 * The GDB remote stub, gdbserver, has been updated to support Windows and
4771 Cygwin debugging. Both single-threaded and multi-threaded programs are
4774 * The "set trust-readonly-sections" command works again. This command was
4775 broken in GDB 6.3, 6.4, and 6.5.
4777 * The "load" command now supports writing to flash memory, if the remote
4778 stub provides the required support.
4780 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4781 longer requires symbolic debug information (e.g. DWARF-2).
4786 unset substitute-path
4787 show substitute-path
4788 Manage a list of substitution rules that GDB uses to rewrite the name
4789 of the directories where the sources are located. This can be useful
4790 for instance when the sources were moved to a different location
4791 between compilation and debugging.
4795 Print each CLI command as it is executed. Each command is prefixed with
4796 a number of `+' symbols representing the nesting depth.
4797 The source command now has a `-v' option to enable the same feature.
4801 The ARM Demon monitor support (RDP protocol, "target rdp").
4803 Kernel Object Display, an embedded debugging feature which only worked with
4804 an obsolete version of Cisco IOS.
4806 The 'set download-write-size' and 'show download-write-size' commands.
4808 * New remote packets
4811 Tell a stub about GDB client features, and request remote target features.
4812 The first feature implemented is PacketSize, which allows the target to
4813 specify the size of packets it can handle - to minimize the number of
4814 packets required and improve performance when connected to a remote
4818 Fetch an OS auxilliary vector from the remote stub. This packet is a
4819 more efficient replacement for qPart:auxv:read.
4821 qXfer:memory-map:read:
4822 Fetch a memory map from the remote stub, including information about
4823 RAM, ROM, and flash memory devices.
4828 Erase and program a flash memory device.
4830 * Removed remote packets
4833 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4834 used it, and only gdbserver implemented it.
4836 *** Changes in GDB 6.5
4840 Renesas M32C/M16C m32c-elf
4842 Morpho Technologies ms1 ms1-elf
4846 init-if-undefined Initialize a convenience variable, but
4847 only if it doesn't already have a value.
4849 The following commands are presently only implemented for native GNU/Linux:
4851 checkpoint Save a snapshot of the program state.
4853 restart <n> Return the program state to a
4854 previously saved state.
4856 info checkpoints List currently saved checkpoints.
4858 delete-checkpoint <n> Delete a previously saved checkpoint.
4860 set|show detach-on-fork Tell gdb whether to detach from a newly
4861 forked process, or to keep debugging it.
4863 info forks List forks of the user program that
4864 are available to be debugged.
4866 fork <n> Switch to debugging one of several
4867 forks of the user program that are
4868 available to be debugged.
4870 delete-fork <n> Delete a fork from the list of forks
4871 that are available to be debugged (and
4872 kill the forked process).
4874 detach-fork <n> Delete a fork from the list of forks
4875 that are available to be debugged (and
4876 allow the process to continue).
4880 Morpho Technologies ms2 ms1-elf
4882 * Improved Windows host support
4884 GDB now builds as a cross debugger hosted on i686-mingw32, including
4885 native console support, and remote communications using either
4886 network sockets or serial ports.
4888 * Improved Modula-2 language support
4890 GDB can now print most types in the Modula-2 syntax. This includes:
4891 basic types, set types, record types, enumerated types, range types,
4892 pointer types and ARRAY types. Procedure var parameters are correctly
4893 printed and hexadecimal addresses and character constants are also
4894 written in the Modula-2 syntax. Best results can be obtained by using
4895 GNU Modula-2 together with the -gdwarf-2 command line option.
4899 The ARM rdi-share module.
4901 The Netware NLM debug server.
4903 *** Changes in GDB 6.4
4905 * New native configurations
4907 OpenBSD/arm arm*-*-openbsd*
4908 OpenBSD/mips64 mips64-*-openbsd*
4912 Morpho Technologies ms1 ms1-elf
4914 * New command line options
4916 --batch-silent As for --batch, but totally silent.
4917 --return-child-result The debugger will exist with the same value
4918 the child (debugged) program exited with.
4919 --eval-command COMMAND, -ex COMMAND
4920 Execute a single GDB CLI command. This may be
4921 specified multiple times and in conjunction
4922 with the --command (-x) option.
4924 * Deprecated commands removed
4926 The following commands, that were deprecated in 2000, have been
4930 set|show arm disassembly-flavor set|show arm disassembler
4931 othernames set arm disassembler
4932 set|show remotedebug set|show debug remote
4933 set|show archdebug set|show debug arch
4934 set|show eventdebug set|show debug event
4937 * New BSD user-level threads support
4939 It is now possible to debug programs using the user-level threads
4940 library on OpenBSD and FreeBSD. Currently supported (target)
4943 FreeBSD/amd64 x86_64-*-freebsd*
4944 FreeBSD/i386 i386-*-freebsd*
4945 OpenBSD/i386 i386-*-openbsd*
4947 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4948 are not yet supported.
4950 * New support for Matsushita MN10300 w/sim added
4951 (Work in progress). mn10300-elf.
4953 * REMOVED configurations and files
4955 VxWorks and the XDR protocol *-*-vxworks
4956 Motorola MCORE mcore-*-*
4957 National Semiconductor NS32000 ns32k-*-*
4959 * New "set print array-indexes" command
4961 After turning this setting "on", GDB prints the index of each element
4962 when displaying arrays. The default is "off" to preserve the previous
4965 * VAX floating point support
4967 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4969 * User-defined command support
4971 In addition to using $arg0..$arg9 for argument passing, it is now possible
4972 to use $argc to determine now many arguments have been passed. See the
4973 section on user-defined commands in the user manual for more information.
4975 *** Changes in GDB 6.3:
4977 * New command line option
4979 GDB now accepts -l followed by a number to set the timeout for remote
4982 * GDB works with GCC -feliminate-dwarf2-dups
4984 GDB now supports a more compact representation of DWARF-2 debug
4985 information using DW_FORM_ref_addr references. These are produced
4986 by GCC with the option -feliminate-dwarf2-dups and also by some
4987 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4988 to use -feliminate-dwarf2-dups.
4990 * Internationalization
4992 When supported by the host system, GDB will be built with
4993 internationalization (libintl). The task of marking up the sources is
4994 continued, we're looking forward to our first translation.
4998 Initial support for debugging programs compiled with the GNAT
4999 implementation of the Ada programming language has been integrated
5000 into GDB. In this release, support is limited to expression evaluation.
5002 * New native configurations
5004 GNU/Linux/m32r m32r-*-linux-gnu
5008 GDB's remote protocol now includes support for the 'p' packet. This
5009 packet is used to fetch individual registers from a remote inferior.
5011 * END-OF-LIFE registers[] compatibility module
5013 GDB's internal register infrastructure has been completely rewritten.
5014 The new infrastructure making possible the implementation of key new
5015 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5018 GDB 6.3 will be the last release to include the the registers[]
5019 compatibility module that allowed out-of-date configurations to
5020 continue to work. This change directly impacts the following
5030 powerpc bdm protocol
5032 Unless there is activity to revive these configurations, they will be
5033 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5035 * OBSOLETE configurations and files
5037 Configurations that have been declared obsolete in this release have
5038 been commented out. Unless there is activity to revive these
5039 configurations, the next release of GDB will have their sources
5040 permanently REMOVED.
5049 *** Changes in GDB 6.2.1:
5051 * MIPS `break main; run' gave an heuristic-fence-post warning
5053 When attempting to run even a simple program, a warning about
5054 heuristic-fence-post being hit would be reported. This problem has
5057 * MIPS IRIX 'long double' crashed GDB
5059 When examining a long double variable, GDB would get a segmentation
5060 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5061 IRIX long double values).
5065 A bug in the VAX stack code was causing problems with the "next"
5066 command. This problem has been fixed.
5068 *** Changes in GDB 6.2:
5070 * Fix for ``many threads''
5072 On GNU/Linux systems that use the NPTL threads library, a program
5073 rapidly creating and deleting threads would confuse GDB leading to the
5076 ptrace: No such process.
5077 thread_db_get_info: cannot get thread info: generic error
5079 This problem has been fixed.
5081 * "-async" and "-noasync" options removed.
5083 Support for the broken "-noasync" option has been removed (it caused
5086 * New ``start'' command.
5088 This command runs the program until the begining of the main procedure.
5090 * New BSD Kernel Data Access Library (libkvm) interface
5092 Using ``target kvm'' it is now possible to debug kernel core dumps and
5093 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5094 platforms. Currently supported (native-only) configurations are:
5096 FreeBSD/amd64 x86_64-*-freebsd*
5097 FreeBSD/i386 i?86-*-freebsd*
5098 NetBSD/i386 i?86-*-netbsd*
5099 NetBSD/m68k m68*-*-netbsd*
5100 NetBSD/sparc sparc-*-netbsd*
5101 OpenBSD/amd64 x86_64-*-openbsd*
5102 OpenBSD/i386 i?86-*-openbsd*
5103 OpenBSD/m68k m68*-openbsd*
5104 OpenBSD/sparc sparc-*-openbsd*
5106 * Signal trampoline code overhauled
5108 Many generic problems with GDB's signal handling code have been fixed.
5109 These include: backtraces through non-contiguous stacks; recognition
5110 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5111 call; backtrace through a signal trampoline; step into and out of
5112 signal handlers; and single-stepping in the signal trampoline.
5114 Please note that kernel bugs are a limiting factor here. These
5115 features have been shown to work on an s390 GNU/Linux system that
5116 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5118 * Cygwin support for DWARF 2 added.
5120 * New native configurations
5122 GNU/Linux/hppa hppa*-*-linux*
5123 OpenBSD/hppa hppa*-*-openbsd*
5124 OpenBSD/m68k m68*-*-openbsd*
5125 OpenBSD/m88k m88*-*-openbsd*
5126 OpenBSD/powerpc powerpc-*-openbsd*
5127 NetBSD/vax vax-*-netbsd*
5128 OpenBSD/vax vax-*-openbsd*
5130 * END-OF-LIFE frame compatibility module
5132 GDB's internal frame infrastructure has been completely rewritten.
5133 The new infrastructure making it possible to support key new features
5134 including DWARF 2 Call Frame Information. To aid in the task of
5135 migrating old configurations to this new infrastructure, a
5136 compatibility module, that allowed old configurations to continue to
5137 work, was also included.
5139 GDB 6.2 will be the last release to include this frame compatibility
5140 module. This change directly impacts the following configurations:
5150 Unless there is activity to revive these configurations, they will be
5151 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5153 * REMOVED configurations and files
5155 Sun 3, running SunOS 3 m68*-*-sunos3*
5156 Sun 3, running SunOS 4 m68*-*-sunos4*
5157 Sun 2, running SunOS 3 m68000-*-sunos3*
5158 Sun 2, running SunOS 4 m68000-*-sunos4*
5159 Motorola 680x0 running LynxOS m68*-*-lynxos*
5160 AT&T 3b1/Unix pc m68*-att-*
5161 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5162 decstation mips-dec-* mips-little-*
5163 riscos mips-*-riscos* mips-*-sysv*
5164 sonymips mips-sony-*
5165 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5167 *** Changes in GDB 6.1.1:
5169 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5171 The TUI (Text-mode User Interface) is now built as part of a default
5172 GDB configuration. It is enabled by either selecting the TUI with the
5173 command line option "-i=tui" or by running the separate "gdbtui"
5174 program. For more information on the TUI, see the manual "Debugging
5177 * Pending breakpoint support (also included in GDB 6.1)
5179 Support has been added to allow you to specify breakpoints in shared
5180 libraries that have not yet been loaded. If a breakpoint location
5181 cannot be found, and the "breakpoint pending" option is set to auto,
5182 GDB queries you if you wish to make the breakpoint pending on a future
5183 shared-library load. If and when GDB resolves the breakpoint symbol,
5184 the pending breakpoint is removed as one or more regular breakpoints
5187 Pending breakpoints are very useful for GCJ Java debugging.
5189 * Fixed ISO-C build problems
5191 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5192 non ISO-C code that stopped them being built using a more strict ISO-C
5193 compiler (e.g., IBM's C compiler).
5195 * Fixed build problem on IRIX 5
5197 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5198 wasn't able to compile compile on an IRIX 5 system.
5200 * Added execute permission to gdb/gdbserver/configure
5202 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5203 permission. This bug would cause configure to fail on a number of
5204 systems (Solaris, IRIX). Ref: server/519.
5206 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5208 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5209 has been updated to use constant array sizes.
5211 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5213 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5214 its generated DWARF Call Frame Info. This encoding was causing GDB to
5215 panic, that panic has been fixed. Ref: gdb/1628.
5217 * Fixed a problem when examining parameters in shared library code.
5219 When examining parameters in optimized shared library code generated
5220 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5221 not available''. GDB now correctly displays the variable's value.
5223 *** Changes in GDB 6.1:
5225 * Removed --with-mmalloc
5227 Support for the mmalloc memory manager has been removed, as it
5228 conflicted with the internal gdb byte cache.
5230 * Changes in AMD64 configurations
5232 The AMD64 target now includes the %cs and %ss registers. As a result
5233 the AMD64 remote protocol has changed; this affects the floating-point
5234 and SSE registers. If you rely on those registers for your debugging,
5235 you should upgrade gdbserver on the remote side.
5237 * Revised SPARC target
5239 The SPARC target has been completely revised, incorporating the
5240 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5241 support for LynxOS and SunOS 4 has been dropped. Calling functions
5242 from within GDB on operating systems with a non-executable stack
5243 (Solaris, OpenBSD) now works.
5247 GDB has a new C++ demangler which does a better job on the mangled
5248 names generated by current versions of g++. It also runs faster, so
5249 with this and other changes gdb should now start faster on large C++
5252 * DWARF 2 Location Expressions
5254 GDB support for location expressions has been extended to support function
5255 arguments and frame bases. Older versions of GDB could crash when they
5258 * C++ nested types and namespaces
5260 GDB's support for nested types and namespaces in C++ has been
5261 improved, especially if you use the DWARF 2 debugging format. (This
5262 is the default for recent versions of GCC on most platforms.)
5263 Specifically, if you have a class "Inner" defined within a class or
5264 namespace "Outer", then GDB realizes that the class's name is
5265 "Outer::Inner", not simply "Inner". This should greatly reduce the
5266 frequency of complaints about not finding RTTI symbols. In addition,
5267 if you are stopped at inside of a function defined within a namespace,
5268 GDB modifies its name lookup accordingly.
5270 * New native configurations
5272 NetBSD/amd64 x86_64-*-netbsd*
5273 OpenBSD/amd64 x86_64-*-openbsd*
5274 OpenBSD/alpha alpha*-*-openbsd*
5275 OpenBSD/sparc sparc-*-openbsd*
5276 OpenBSD/sparc64 sparc64-*-openbsd*
5278 * New debugging protocols
5280 M32R with SDI protocol m32r-*-elf*
5282 * "set prompt-escape-char" command deleted.
5284 The command "set prompt-escape-char" has been deleted. This command,
5285 and its very obscure effet on GDB's prompt, was never documented,
5286 tested, nor mentioned in the NEWS file.
5288 * OBSOLETE configurations and files
5290 Configurations that have been declared obsolete in this release have
5291 been commented out. Unless there is activity to revive these
5292 configurations, the next release of GDB will have their sources
5293 permanently REMOVED.
5295 Sun 3, running SunOS 3 m68*-*-sunos3*
5296 Sun 3, running SunOS 4 m68*-*-sunos4*
5297 Sun 2, running SunOS 3 m68000-*-sunos3*
5298 Sun 2, running SunOS 4 m68000-*-sunos4*
5299 Motorola 680x0 running LynxOS m68*-*-lynxos*
5300 AT&T 3b1/Unix pc m68*-att-*
5301 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5302 decstation mips-dec-* mips-little-*
5303 riscos mips-*-riscos* mips-*-sysv*
5304 sonymips mips-sony-*
5305 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5307 * REMOVED configurations and files
5309 SGI Irix-4.x mips-sgi-irix4 or iris4
5310 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5311 Z8000 simulator z8k-zilog-none or z8ksim
5312 Matsushita MN10200 w/simulator mn10200-*-*
5313 H8/500 simulator h8500-hitachi-hms or h8500hms
5314 HP/PA running BSD hppa*-*-bsd*
5315 HP/PA running OSF/1 hppa*-*-osf*
5316 HP/PA Pro target hppa*-*-pro*
5317 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5318 386BSD i[3456]86-*-bsd*
5319 Sequent family i[3456]86-sequent-sysv4*
5320 i[3456]86-sequent-sysv*
5321 i[3456]86-sequent-bsd*
5322 SPARC running LynxOS sparc-*-lynxos*
5323 SPARC running SunOS 4 sparc-*-sunos4*
5324 Tsqware Sparclet sparclet-*-*
5325 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5327 *** Changes in GDB 6.0:
5331 Support for debugging the Objective-C programming language has been
5332 integrated into GDB.
5334 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5336 DWARF 2's Call Frame Information makes available compiler generated
5337 information that more exactly describes the program's run-time stack.
5338 By using this information, GDB is able to provide more robust stack
5341 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5342 have been updated to use a new backtrace mechanism which includes
5343 DWARF 2 CFI support.
5347 GDB's remote protocol has been extended to include support for hosted
5348 file I/O (where the remote target uses GDB's file system). See GDB's
5349 remote protocol documentation for details.
5351 * All targets using the new architecture framework.
5353 All of GDB's targets have been updated to use the new internal
5354 architecture framework. The way is now open for future GDB releases
5355 to include cross-architecture native debugging support (i386 on amd64,
5358 * GNU/Linux's Thread Local Storage (TLS)
5360 GDB now includes support for for the GNU/Linux implementation of
5361 per-thread variables.
5363 * GNU/Linux's Native POSIX Thread Library (NPTL)
5365 GDB's thread code has been updated to work with either the new
5366 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5368 * Separate debug info.
5370 GDB, in conjunction with BINUTILS, now supports a mechanism for
5371 automatically loading debug information from a separate file. Instead
5372 of shipping full debug and non-debug versions of system libraries,
5373 system integrators can now instead ship just the stripped libraries
5374 and optional debug files.
5376 * DWARF 2 Location Expressions
5378 DWARF 2 Location Expressions allow the compiler to more completely
5379 describe the location of variables (even in optimized code) to the
5382 GDB now includes preliminary support for location expressions (support
5383 for DW_OP_piece is still missing).
5387 A number of long standing bugs that caused GDB to die while starting a
5388 Java application have been fixed. GDB's Java support is now
5389 considered "useable".
5391 * GNU/Linux support for fork, vfork, and exec.
5393 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5394 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5397 * GDB supports logging output to a file
5399 There are two new commands, "set logging" and "show logging", which can be
5400 used to capture GDB's output to a file.
5402 * The meaning of "detach" has changed for gdbserver
5404 The "detach" command will now resume the application, as documented. To
5405 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5408 * d10v, m68hc11 `regs' command deprecated
5410 The `info registers' command has been updated so that it displays the
5411 registers using a format identical to the old `regs' command.
5415 A new command, "maint set profile on/off", has been added. This command can
5416 be used to enable or disable profiling while running GDB, to profile a
5417 session or a set of commands. In addition there is a new configure switch,
5418 "--enable-profiling", which will cause GDB to be compiled with profiling
5419 data, for more informative profiling results.
5421 * Default MI syntax changed to "mi2".
5423 The default MI (machine interface) syntax, enabled by the command line
5424 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5425 "mi1", can be enabled by specifying the option "-i=mi1".
5427 Support for the original "mi0" syntax (included in GDB 5.0) has been
5430 Fix for gdb/192: removed extraneous space when displaying frame level.
5431 Fix for gdb/672: update changelist is now output in mi list format.
5432 Fix for gdb/702: a -var-assign that updates the value now shows up
5433 in a subsequent -var-update.
5435 * New native configurations.
5437 FreeBSD/amd64 x86_64-*-freebsd*
5439 * Multi-arched targets.
5441 HP/PA HPUX11 hppa*-*-hpux*
5442 Renesas M32R/D w/simulator m32r-*-elf*
5444 * OBSOLETE configurations and files
5446 Configurations that have been declared obsolete in this release have
5447 been commented out. Unless there is activity to revive these
5448 configurations, the next release of GDB will have their sources
5449 permanently REMOVED.
5451 Z8000 simulator z8k-zilog-none or z8ksim
5452 Matsushita MN10200 w/simulator mn10200-*-*
5453 H8/500 simulator h8500-hitachi-hms or h8500hms
5454 HP/PA running BSD hppa*-*-bsd*
5455 HP/PA running OSF/1 hppa*-*-osf*
5456 HP/PA Pro target hppa*-*-pro*
5457 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5458 Sequent family i[3456]86-sequent-sysv4*
5459 i[3456]86-sequent-sysv*
5460 i[3456]86-sequent-bsd*
5461 Tsqware Sparclet sparclet-*-*
5462 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5464 * REMOVED configurations and files
5467 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5468 IBM AIX PS/2 i[3456]86-*-aix
5469 i386 running Mach 3.0 i[3456]86-*-mach3*
5470 i386 running Mach i[3456]86-*-mach*
5471 i386 running OSF/1 i[3456]86-*osf1mk*
5472 HP/Apollo 68k Family m68*-apollo*-sysv*,
5474 m68*-hp-bsd*, m68*-hp-hpux*
5475 Argonaut Risc Chip (ARC) arc-*-*
5476 Mitsubishi D30V d30v-*-*
5477 Fujitsu FR30 fr30-*-elf*
5478 OS/9000 i[34]86-*-os9k
5479 I960 with MON960 i960-*-coff
5481 * MIPS $fp behavior changed
5483 The convenience variable $fp, for the MIPS, now consistently returns
5484 the address of the current frame's base. Previously, depending on the
5485 context, $fp could refer to either $sp or the current frame's base
5486 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5487 The GNU Source-Level Debugger''.
5489 *** Changes in GDB 5.3:
5491 * GNU/Linux shared library multi-threaded performance improved.
5493 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5494 `/proc', in preference to `ptrace' for memory reads. This may result
5495 in an improvement in the start-up time of multi-threaded, shared
5496 library applications when run under GDB. One GDB user writes: ``loads
5497 shared libs like mad''.
5499 * ``gdbserver'' now supports multi-threaded applications on some targets
5501 Support for debugging multi-threaded applications which use
5502 the GNU/Linux LinuxThreads package has been added for
5503 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5504 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5506 * GDB now supports C/C++ preprocessor macros.
5508 GDB now expands preprocessor macro invocations in C/C++ expressions,
5509 and provides various commands for showing macro definitions and how
5512 The new command `macro expand EXPRESSION' expands any macro
5513 invocations in expression, and shows the result.
5515 The new command `show macro MACRO-NAME' shows the definition of the
5516 macro named MACRO-NAME, and where it was defined.
5518 Most compilers don't include information about macros in the debugging
5519 information by default. In GCC 3.1, for example, you need to compile
5520 your program with the options `-gdwarf-2 -g3'. If the macro
5521 information is present in the executable, GDB will read it.
5523 * Multi-arched targets.
5525 DEC Alpha (partial) alpha*-*-*
5526 DEC VAX (partial) vax-*-*
5528 National Semiconductor NS32000 (partial) ns32k-*-*
5529 Motorola 68000 (partial) m68k-*-*
5530 Motorola MCORE mcore-*-*
5534 Fujitsu FRV architecture added by Red Hat frv*-*-*
5537 * New native configurations
5539 Alpha NetBSD alpha*-*-netbsd*
5540 SH NetBSD sh*-*-netbsdelf*
5541 MIPS NetBSD mips*-*-netbsd*
5542 UltraSPARC NetBSD sparc64-*-netbsd*
5544 * OBSOLETE configurations and files
5546 Configurations that have been declared obsolete in this release have
5547 been commented out. Unless there is activity to revive these
5548 configurations, the next release of GDB will have their sources
5549 permanently REMOVED.
5551 Mitsubishi D30V d30v-*-*
5552 OS/9000 i[34]86-*-os9k
5553 IBM AIX PS/2 i[3456]86-*-aix
5554 Fujitsu FR30 fr30-*-elf*
5555 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5556 Argonaut Risc Chip (ARC) arc-*-*
5557 i386 running Mach 3.0 i[3456]86-*-mach3*
5558 i386 running Mach i[3456]86-*-mach*
5559 i386 running OSF/1 i[3456]86-*osf1mk*
5560 HP/Apollo 68k Family m68*-apollo*-sysv*,
5562 m68*-hp-bsd*, m68*-hp-hpux*
5563 I960 with MON960 i960-*-coff
5565 * OBSOLETE languages
5567 CHILL, a Pascal like language used by telecommunications companies.
5569 * REMOVED configurations and files
5571 AMD 29k family via UDI a29k-amd-udi, udi29k
5572 A29K VxWorks a29k-*-vxworks
5573 AMD 29000 embedded, using EBMON a29k-none-none
5574 AMD 29000 embedded with COFF a29k-none-coff
5575 AMD 29000 embedded with a.out a29k-none-aout
5577 testsuite/gdb.hp/gdb.threads-hp/ directory
5579 * New command "set max-user-call-depth <nnn>"
5581 This command allows the user to limit the call depth of user-defined
5582 commands. The default is 1024.
5584 * Changes in FreeBSD/i386 native debugging.
5586 Support for the "generate-core-file" has been added.
5588 * New commands "dump", "append", and "restore".
5590 These commands allow data to be copied from target memory
5591 to a bfd-format or binary file (dump and append), and back
5592 from a file into memory (restore).
5594 * Improved "next/step" support on multi-processor Alpha Tru64.
5596 The previous single-step mechanism could cause unpredictable problems,
5597 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5598 of a software single-step mechanism prevents this.
5600 *** Changes in GDB 5.2.1:
5608 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5609 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5610 Fix, by Joel Brobecker imported from mainline.
5612 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5613 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5614 Fix, by Fred Fish, imported from mainline.
5616 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5617 Surprisingly enough, it works now.
5618 By Michal Ludvig, imported from mainline.
5620 i386 hardware watchpoint support:
5621 avoid misses on second run for some targets.
5622 By Pierre Muller, imported from mainline.
5624 *** Changes in GDB 5.2:
5626 * New command "set trust-readonly-sections on[off]".
5628 This command is a hint that tells gdb that read-only sections
5629 really are read-only (ie. that their contents will not change).
5630 In this mode, gdb will go to the object file rather than the
5631 target to read memory from read-only sections (such as ".text").
5632 This can be a significant performance improvement on some
5633 (notably embedded) targets.
5635 * New command "generate-core-file" (or "gcore").
5637 This new gdb command allows the user to drop a core file of the child
5638 process state at any time. So far it's been implemented only for
5639 GNU/Linux and Solaris, but should be relatively easily ported to other
5640 hosts. Argument is core file name (defaults to core.<pid>).
5642 * New command line option
5644 GDB now accepts --pid or -p followed by a process id.
5646 * Change in command line behavior -- corefiles vs. process ids.
5648 There is a subtle behavior in the way in which GDB handles
5649 command line arguments. The first non-flag argument is always
5650 a program to debug, but the second non-flag argument may either
5651 be a corefile or a process id. Previously, GDB would attempt to
5652 open the second argument as a corefile, and if that failed, would
5653 issue a superfluous error message and then attempt to attach it as
5654 a process. Now, if the second argument begins with a non-digit,
5655 it will be treated as a corefile. If it begins with a digit,
5656 GDB will attempt to attach it as a process, and if no such process
5657 is found, will then attempt to open it as a corefile.
5659 * Changes in ARM configurations.
5661 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5662 configuration is fully multi-arch.
5664 * New native configurations
5666 ARM NetBSD arm*-*-netbsd*
5667 x86 OpenBSD i[3456]86-*-openbsd*
5668 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5669 Sparc64 running FreeBSD sparc64-*-freebsd*
5673 Sanyo XStormy16 xstormy16-elf
5675 * OBSOLETE configurations and files
5677 Configurations that have been declared obsolete in this release have
5678 been commented out. Unless there is activity to revive these
5679 configurations, the next release of GDB will have their sources
5680 permanently REMOVED.
5682 AMD 29k family via UDI a29k-amd-udi, udi29k
5683 A29K VxWorks a29k-*-vxworks
5684 AMD 29000 embedded, using EBMON a29k-none-none
5685 AMD 29000 embedded with COFF a29k-none-coff
5686 AMD 29000 embedded with a.out a29k-none-aout
5688 testsuite/gdb.hp/gdb.threads-hp/ directory
5690 * REMOVED configurations and files
5692 TI TMS320C80 tic80-*-*
5694 PowerPC Solaris powerpcle-*-solaris*
5695 PowerPC Windows NT powerpcle-*-cygwin32
5696 PowerPC Netware powerpc-*-netware*
5697 Harris/CXUX m88k m88*-harris-cxux*
5698 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5699 ns32k-utek-sysv* ns32k-utek-*
5700 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5701 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5702 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5703 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5704 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5706 * Changes to command line processing
5708 The new `--args' feature can be used to specify command-line arguments
5709 for the inferior from gdb's command line.
5711 * Changes to key bindings
5713 There is a new `operate-and-get-next' function bound to `C-o'.
5715 *** Changes in GDB 5.1.1
5717 Fix compile problem on DJGPP.
5719 Fix a problem with floating-point registers on the i386 being
5722 Fix to stop GDB crashing on .debug_str debug info.
5724 Numerous documentation fixes.
5726 Numerous testsuite fixes.
5728 *** Changes in GDB 5.1:
5730 * New native configurations
5732 Alpha FreeBSD alpha*-*-freebsd*
5733 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5734 MIPS GNU/Linux mips*-*-linux*
5735 MIPS SGI Irix 6.x mips*-sgi-irix6*
5736 ia64 AIX ia64-*-aix*
5737 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5741 Motorola 68HC11 and 68HC12 m68hc11-elf
5743 UltraSparc running GNU/Linux sparc64-*-linux*
5745 * OBSOLETE configurations and files
5747 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5748 Harris/CXUX m88k m88*-harris-cxux*
5749 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5750 ns32k-utek-sysv* ns32k-utek-*
5751 TI TMS320C80 tic80-*-*
5753 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5754 PowerPC Solaris powerpcle-*-solaris*
5755 PowerPC Windows NT powerpcle-*-cygwin32
5756 PowerPC Netware powerpc-*-netware*
5757 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5758 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5759 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5760 Apple Macintosh (MPW) host N/A
5762 stuff.c (Program to stuff files into a specially prepared space in kdb)
5763 kdb-start.c (Main loop for the standalone kernel debugger)
5765 Configurations that have been declared obsolete in this release have
5766 been commented out. Unless there is activity to revive these
5767 configurations, the next release of GDB will have their sources
5768 permanently REMOVED.
5770 * REMOVED configurations and files
5772 Altos 3068 m68*-altos-*
5773 Convex c1-*-*, c2-*-*
5775 ARM RISCix arm-*-* (as host)
5779 * GDB has been converted to ISO C.
5781 GDB's source code has been converted to ISO C. In particular, the
5782 sources are fully protoized, and rely on standard headers being
5787 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5789 * The MI enabled by default.
5791 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5792 revised and enabled by default. Packages which use GDB as a debugging
5793 engine behind a UI or another front end are encouraged to switch to
5794 using the GDB/MI interface, instead of the old annotations interface
5795 which is now deprecated.
5797 * Support for debugging Pascal programs.
5799 GDB now includes support for debugging Pascal programs. The following
5800 main features are supported:
5802 - Pascal-specific data types such as sets;
5804 - automatic recognition of Pascal sources based on file-name
5807 - Pascal-style display of data types, variables, and functions;
5809 - a Pascal expression parser.
5811 However, some important features are not yet supported.
5813 - Pascal string operations are not supported at all;
5815 - there are some problems with boolean types;
5817 - Pascal type hexadecimal constants are not supported
5818 because they conflict with the internal variables format;
5820 - support for Pascal objects and classes is not full yet;
5822 - unlike Pascal, GDB is case-sensitive for symbol names.
5824 * Changes in completion.
5826 Commands such as `shell', `run' and `set args', which pass arguments
5827 to inferior programs, now complete on file names, similar to what
5828 users expect at the shell prompt.
5830 Commands which accept locations, such as `disassemble', `print',
5831 `breakpoint', `until', etc. now complete on filenames as well as
5832 program symbols. Thus, if you type "break foob TAB", and the source
5833 files linked into the programs include `foobar.c', that file name will
5834 be one of the candidates for completion. However, file names are not
5835 considered for completion after you typed a colon that delimits a file
5836 name from a name of a function in that file, as in "break foo.c:bar".
5838 `set demangle-style' completes on available demangling styles.
5840 * New platform-independent commands:
5842 It is now possible to define a post-hook for a command as well as a
5843 hook that runs before the command. For more details, see the
5844 documentation of `hookpost' in the GDB manual.
5846 * Changes in GNU/Linux native debugging.
5848 Support for debugging multi-threaded programs has been completely
5849 revised for all platforms except m68k and sparc. You can now debug as
5850 many threads as your system allows you to have.
5852 Attach/detach is supported for multi-threaded programs.
5854 Support for SSE registers was added for x86. This doesn't work for
5855 multi-threaded programs though.
5857 * Changes in MIPS configurations.
5859 Multi-arch support is enabled for all MIPS configurations.
5861 GDB can now be built as native debugger on SGI Irix 6.x systems for
5862 debugging n32 executables. (Debugging 64-bit executables is not yet
5865 * Unified support for hardware watchpoints in all x86 configurations.
5867 Most (if not all) native x86 configurations support hardware-assisted
5868 breakpoints and watchpoints in a unified manner. This support
5869 implements debug register sharing between watchpoints, which allows to
5870 put a virtually infinite number of watchpoints on the same address,
5871 and also supports watching regions up to 16 bytes with several debug
5874 The new maintenance command `maintenance show-debug-regs' toggles
5875 debugging print-outs in functions that insert, remove, and test
5876 watchpoints and hardware breakpoints.
5878 * Changes in the DJGPP native configuration.
5880 New command ``info dos sysinfo'' displays assorted information about
5881 the CPU, OS, memory, and DPMI server.
5883 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5884 display information about segment descriptors stored in GDT, LDT, and
5887 New commands ``info dos pde'' and ``info dos pte'' display entries
5888 from Page Directory and Page Tables (for now works with CWSDPMI only).
5889 New command ``info dos address-pte'' displays the Page Table entry for
5890 a given linear address.
5892 GDB can now pass command lines longer than 126 characters to the
5893 program being debugged (requires an update to the libdbg.a library
5894 which is part of the DJGPP development kit).
5896 DWARF2 debug info is now supported.
5898 It is now possible to `step' and `next' through calls to `longjmp'.
5900 * Changes in documentation.
5902 All GDB documentation was converted to GFDL, the GNU Free
5903 Documentation License.
5905 Tracepoints-related commands are now fully documented in the GDB
5908 TUI, the Text-mode User Interface, is now documented in the manual.
5910 Tracepoints-related commands are now fully documented in the GDB
5913 The "GDB Internals" manual now has an index. It also includes
5914 documentation of `ui_out' functions, GDB coding standards, x86
5915 hardware watchpoints, and memory region attributes.
5917 * GDB's version number moved to ``version.in''
5919 The Makefile variable VERSION has been replaced by the file
5920 ``version.in''. People creating GDB distributions should update the
5921 contents of this file.
5925 GUD support is now a standard part of the EMACS distribution.
5927 *** Changes in GDB 5.0:
5929 * Improved support for debugging FP programs on x86 targets
5931 Unified and much-improved support for debugging floating-point
5932 programs on all x86 targets. In particular, ``info float'' now
5933 displays the FP registers in the same format on all x86 targets, with
5934 greater level of detail.
5936 * Improvements and bugfixes in hardware-assisted watchpoints
5938 It is now possible to watch array elements, struct members, and
5939 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5940 on x86 targets no longer erroneously trigger when the address is
5943 * Improvements in the native DJGPP version of GDB
5945 The distribution now includes all the scripts and auxiliary files
5946 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5947 machines ``out of the box''.
5949 The DJGPP version can now debug programs that use signals. It is
5950 possible to catch signals that happened in the debuggee, deliver
5951 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5952 would kill the program being debugged.) Programs that hook hardware
5953 interrupts (keyboard, timer, etc.) can also be debugged.
5955 It is now possible to debug DJGPP programs that redirect their
5956 standard handles or switch them to raw (as opposed to cooked) mode, or
5957 even close them. The command ``run < foo > bar'' works as expected,
5958 and ``info terminal'' reports useful information about the debuggee's
5959 terminal, including raw/cooked mode, redirection, etc.
5961 The DJGPP version now uses termios functions for console I/O, which
5962 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5965 DOS-style file names with drive letters are now fully supported by
5968 It is now possible to debug DJGPP programs that switch their working
5969 directory. It is also possible to rerun the debuggee any number of
5970 times without restarting GDB; thus, you can use the same setup,
5971 breakpoints, etc. for many debugging sessions.
5973 * New native configurations
5975 ARM GNU/Linux arm*-*-linux*
5976 PowerPC GNU/Linux powerpc-*-linux*
5980 Motorola MCore mcore-*-*
5981 x86 VxWorks i[3456]86-*-vxworks*
5982 PowerPC VxWorks powerpc-*-vxworks*
5983 TI TMS320C80 tic80-*-*
5985 * OBSOLETE configurations
5987 Altos 3068 m68*-altos-*
5988 Convex c1-*-*, c2-*-*
5990 ARM RISCix arm-*-* (as host)
5993 Configurations that have been declared obsolete will be commented out,
5994 but the code will be left in place. If there is no activity to revive
5995 these configurations before the next release of GDB, the sources will
5996 be permanently REMOVED.
5998 * Gould support removed
6000 Support for the Gould PowerNode and NP1 has been removed.
6002 * New features for SVR4
6004 On SVR4 native platforms (such as Solaris), if you attach to a process
6005 without first loading a symbol file, GDB will now attempt to locate and
6006 load symbols from the running process's executable file.
6008 * Many C++ enhancements
6010 C++ support has been greatly improved. Overload resolution now works properly
6011 in almost all cases. RTTI support is on the way.
6013 * Remote targets can connect to a sub-program
6015 A popen(3) style serial-device has been added. This device starts a
6016 sub-process (such as a stand-alone simulator) and then communicates
6017 with that. The sub-program to run is specified using the syntax
6018 ``|<program> <args>'' vis:
6020 (gdb) set remotedebug 1
6021 (gdb) target extended-remote |mn10300-elf-sim program-args
6023 * MIPS 64 remote protocol
6025 A long standing bug in the mips64 remote protocol where by GDB
6026 expected certain 32 bit registers (ex SR) to be transfered as 32
6027 instead of 64 bits has been fixed.
6029 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6030 added to provide backward compatibility with older versions of GDB.
6032 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6034 The command ``set remotebinarydownload'' command has been replaced by
6035 ``set remote X-packet''. Other commands in ``set remote'' family
6036 include ``set remote P-packet''.
6038 * Breakpoint commands accept ranges.
6040 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6041 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6042 ``tracepoint passcount'' also accepts a range of tracepoints.
6044 * ``apropos'' command added.
6046 The ``apropos'' command searches through command names and
6047 documentation strings, printing out matches, making it much easier to
6048 try to find a command that does what you are looking for.
6052 A new machine oriented interface (MI) has been added to GDB. This
6053 interface is designed for debug environments running GDB as a separate
6054 process. This is part of the long term libGDB project. See the
6055 "GDB/MI" chapter of the GDB manual for further information. It can be
6056 enabled by configuring with:
6058 .../configure --enable-gdbmi
6060 *** Changes in GDB-4.18:
6062 * New native configurations
6064 HP-UX 10.20 hppa*-*-hpux10.20
6065 HP-UX 11.x hppa*-*-hpux11.0*
6066 M68K GNU/Linux m68*-*-linux*
6070 Fujitsu FR30 fr30-*-elf*
6071 Intel StrongARM strongarm-*-*
6072 Mitsubishi D30V d30v-*-*
6074 * OBSOLETE configurations
6076 Gould PowerNode, NP1 np1-*-*, pn-*-*
6078 Configurations that have been declared obsolete will be commented out,
6079 but the code will be left in place. If there is no activity to revive
6080 these configurations before the next release of GDB, the sources will
6081 be permanently REMOVED.
6085 As a compatibility experiment, GDB's source files buildsym.h and
6086 buildsym.c have been converted to pure standard C, no longer
6087 containing any K&R compatibility code. We believe that all systems in
6088 use today either come with a standard C compiler, or have a GCC port
6089 available. If this is not true, please report the affected
6090 configuration to bug-gdb@gnu.org immediately. See the README file for
6091 information about getting a standard C compiler if you don't have one
6096 GDB now uses readline 2.2.
6098 * set extension-language
6100 You can now control the mapping between filename extensions and source
6101 languages by using the `set extension-language' command. For instance,
6102 you can ask GDB to treat .c files as C++ by saying
6103 set extension-language .c c++
6104 The command `info extensions' lists all of the recognized extensions
6105 and their associated languages.
6107 * Setting processor type for PowerPC and RS/6000
6109 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6110 you can use the `set processor' command to specify what variant of the
6111 PowerPC family you are debugging. The command
6115 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6116 following PowerPC and RS6000 variants:
6118 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6119 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6121 403GC IBM PowerPC 403GC
6122 505 Motorola PowerPC 505
6123 860 Motorola PowerPC 860 or 850
6124 601 Motorola PowerPC 601
6125 602 Motorola PowerPC 602
6126 603 Motorola/IBM PowerPC 603 or 603e
6127 604 Motorola PowerPC 604 or 604e
6128 750 Motorola/IBM PowerPC 750 or 750
6130 At the moment, this command just tells GDB what to name the
6131 special-purpose processor registers. Since almost all the affected
6132 registers are inaccessible to user-level programs, this command is
6133 only useful for remote debugging in its present form.
6137 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6138 more extensive support for HP-UX. Added features include shared
6139 library support, kernel threads and hardware watchpoints for 11.00,
6140 support for HP's ANSI C and C++ compilers, and a compatibility mode
6141 for xdb and dbx commands.
6145 HP's donation includes the new concept of catchpoints, which is a
6146 generalization of the old catch command. On HP-UX, it is now possible
6147 to catch exec, fork, and vfork, as well as library loading.
6149 This means that the existing catch command has changed; its first
6150 argument now specifies the type of catch to be set up. See the
6151 output of "help catch" for a list of catchpoint types.
6153 * Debugging across forks
6155 On HP-UX, you can choose which process to debug when a fork() happens
6160 HP has donated a curses-based terminal user interface (TUI). To get
6161 it, build with --enable-tui. Although this can be enabled for any
6162 configuration, at present it only works for native HP debugging.
6164 * GDB remote protocol additions
6166 A new protocol packet 'X' that writes binary data is now available.
6167 Default behavior is to try 'X', then drop back to 'M' if the stub
6168 fails to respond. The settable variable `remotebinarydownload'
6169 allows explicit control over the use of 'X'.
6171 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6172 full 64-bit address. The command
6174 set remoteaddresssize 32
6176 can be used to revert to the old behaviour. For existing remote stubs
6177 the change should not be noticed, as the additional address information
6180 In order to assist in debugging stubs, you may use the maintenance
6181 command `packet' to send any text string to the stub. For instance,
6183 maint packet heythere
6185 sends the packet "$heythere#<checksum>". Note that it is very easy to
6186 disrupt a debugging session by sending the wrong packet at the wrong
6189 The compare-sections command allows you to compare section data on the
6190 target to what is in the executable file without uploading or
6191 downloading, by comparing CRC checksums.
6193 * Tracing can collect general expressions
6195 You may now collect general expressions at tracepoints. This requires
6196 further additions to the target-side stub; see tracepoint.c and
6197 doc/agentexpr.texi for further details.
6199 * mask-address variable for Mips
6201 For Mips targets, you may control the zeroing of the upper 32 bits of
6202 a 64-bit address by entering `set mask-address on'. This is mainly
6203 of interest to users of embedded R4xxx and R5xxx processors.
6205 * Higher serial baud rates
6207 GDB's serial code now allows you to specify baud rates 57600, 115200,
6208 230400, and 460800 baud. (Note that your host system may not be able
6209 to achieve all of these rates.)
6213 The i960 configuration now includes an initial implementation of a
6214 builtin simulator, contributed by Jim Wilson.
6217 *** Changes in GDB-4.17:
6219 * New native configurations
6221 Alpha GNU/Linux alpha*-*-linux*
6222 Unixware 2.x i[3456]86-unixware2*
6223 Irix 6.x mips*-sgi-irix6*
6224 PowerPC GNU/Linux powerpc-*-linux*
6225 PowerPC Solaris powerpcle-*-solaris*
6226 Sparc GNU/Linux sparc-*-linux*
6227 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6231 Argonaut Risc Chip (ARC) arc-*-*
6232 Hitachi H8/300S h8300*-*-*
6233 Matsushita MN10200 w/simulator mn10200-*-*
6234 Matsushita MN10300 w/simulator mn10300-*-*
6235 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6236 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6237 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6238 Mitsubishi D10V w/simulator d10v-*-*
6239 Mitsubishi M32R/D w/simulator m32r-*-elf*
6240 Tsqware Sparclet sparclet-*-*
6241 NEC V850 w/simulator v850-*-*
6243 * New debugging protocols
6245 ARM with RDI protocol arm*-*-*
6246 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6247 DDB and LSI variants of PMON protocol mips*-*-*
6248 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6249 PowerPC with SDS protocol powerpc{,le}-*-eabi
6250 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6254 All configurations can now understand and use the DWARF 2 debugging
6255 format. The choice is automatic, if the symbol file contains DWARF 2
6260 GDB now includes basic Java language support. This support is
6261 only useful with Java compilers that produce native machine code.
6263 * solib-absolute-prefix and solib-search-path
6265 For SunOS and SVR4 shared libraries, you may now set the prefix for
6266 loading absolute shared library symbol files, and the search path for
6267 locating non-absolute shared library symbol files.
6269 * Live range splitting
6271 GDB can now effectively debug code for which GCC has performed live
6272 range splitting as part of its optimization. See gdb/doc/LRS for
6273 more details on the expected format of the stabs information.
6277 GDB's support for the GNU Hurd, including thread debugging, has been
6278 updated to work with current versions of the Hurd.
6282 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6283 instruction set. ARM GDB automatically detects when Thumb
6284 instructions are in use, and adjusts disassembly and backtracing
6289 GDB's MIPS target configurations now handle the MIP16 16-bit
6294 GDB now includes support for overlays; if an executable has been
6295 linked such that multiple sections are based at the same address, GDB
6296 will decide which section to use for symbolic info. You can choose to
6297 control the decision manually, using overlay commands, or implement
6298 additional target-side support and use "overlay load-target" to bring
6299 in the overlay mapping. Do "help overlay" for more detail.
6303 The command "info symbol <address>" displays information about
6304 the symbol at the specified address.
6308 The standard remote protocol now includes an extension that allows
6309 asynchronous collection and display of trace data. This requires
6310 extensive support in the target-side debugging stub. Tracing mode
6311 includes a new interaction mode in GDB and new commands: see the
6312 file tracepoint.c for more details.
6316 Configurations for embedded MIPS now include a simulator contributed
6317 by Cygnus Solutions. The simulator supports the instruction sets
6318 of most MIPS variants.
6322 Sparc configurations may now include the ERC32 simulator contributed
6323 by the European Space Agency. The simulator is not built into
6324 Sparc targets by default; configure with --enable-sim to include it.
6328 For target configurations that may include multiple variants of a
6329 basic architecture (such as MIPS and SH), you may now set the
6330 architecture explicitly. "set arch" sets, "info arch" lists
6331 the possible architectures.
6333 *** Changes in GDB-4.16:
6335 * New native configurations
6337 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6338 M68K NetBSD m68k-*-netbsd*
6339 PowerPC AIX 4.x powerpc-*-aix*
6340 PowerPC MacOS powerpc-*-macos*
6341 PowerPC Windows NT powerpcle-*-cygwin32
6342 RS/6000 AIX 4.x rs6000-*-aix4*
6346 ARM with RDP protocol arm-*-*
6347 I960 with MON960 i960-*-coff
6348 MIPS VxWorks mips*-*-vxworks*
6349 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6350 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6352 Matra Sparclet sparclet-*-*
6356 The powerpc-eabi configuration now includes the PSIM simulator,
6357 contributed by Andrew Cagney, with assistance from Mike Meissner.
6358 PSIM is a very elaborate model of the PowerPC, including not only
6359 basic instruction set execution, but also details of execution unit
6360 performance and I/O hardware. See sim/ppc/README for more details.
6364 GDB now works with Solaris 2.5.
6366 * Windows 95/NT native
6368 GDB will now work as a native debugger on Windows 95 and Windows NT.
6369 To build it from source, you must use the "gnu-win32" environment,
6370 which uses a DLL to emulate enough of Unix to run the GNU tools.
6371 Further information, binaries, and sources are available at
6372 ftp.cygnus.com, under pub/gnu-win32.
6374 * dont-repeat command
6376 If a user-defined command includes the command `dont-repeat', then the
6377 command will not be repeated if the user just types return. This is
6378 useful if the command is time-consuming to run, so that accidental
6379 extra keystrokes don't run the same command many times.
6381 * Send break instead of ^C
6383 The standard remote protocol now includes an option to send a break
6384 rather than a ^C to the target in order to interrupt it. By default,
6385 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6387 * Remote protocol timeout
6389 The standard remote protocol includes a new variable `remotetimeout'
6390 that allows you to set the number of seconds before GDB gives up trying
6391 to read from the target. The default value is 2.
6393 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6395 By default GDB will automatically keep track of objects as they are
6396 loaded and unloaded by the dynamic linker. By using the command `set
6397 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6398 when shared library events occur, thus allowing you to set breakpoints
6399 in shared libraries which are explicitly loaded by the inferior.
6401 Note this feature does not work on hpux8. On hpux9 you must link
6402 /usr/lib/end.o into your program. This feature should work
6403 automatically on hpux10.
6405 * Irix 5.x hardware watchpoint support
6407 Irix 5 configurations now support the use of hardware watchpoints.
6409 * Mips protocol "SYN garbage limit"
6411 When debugging a Mips target using the `target mips' protocol, you
6412 may set the number of characters that GDB will ignore by setting
6413 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6414 every character. The default value is 1050.
6416 * Recording and replaying remote debug sessions
6418 If you set `remotelogfile' to the name of a file, gdb will write to it
6419 a recording of a remote debug session. This recording may then be
6420 replayed back to gdb using "gdbreplay". See gdbserver/README for
6421 details. This is useful when you have a problem with GDB while doing
6422 remote debugging; you can make a recording of the session and send it
6423 to someone else, who can then recreate the problem.
6425 * Speedups for remote debugging
6427 GDB includes speedups for downloading and stepping MIPS systems using
6428 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6429 and more efficient S-record downloading.
6431 * Memory use reductions and statistics collection
6433 GDB now uses less memory and reports statistics about memory usage.
6434 Try the `maint print statistics' command, for example.
6436 *** Changes in GDB-4.15:
6438 * Psymtabs for XCOFF
6440 The symbol reader for AIX GDB now uses partial symbol tables. This
6441 can greatly improve startup time, especially for large executables.
6443 * Remote targets use caching
6445 Remote targets now use a data cache to speed up communication with the
6446 remote side. The data cache could lead to incorrect results because
6447 it doesn't know about volatile variables, thus making it impossible to
6448 debug targets which use memory mapped I/O devices. `set remotecache
6449 off' turns the the data cache off.
6451 * Remote targets may have threads
6453 The standard remote protocol now includes support for multiple threads
6454 in the target system, using new protocol commands 'H' and 'T'. See
6455 gdb/remote.c for details.
6459 If GDB is configured with `--enable-netrom', then it will include
6460 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6461 acts as though it is a bank of ROM on the target board, but you can
6462 write into it over the network. GDB's support consists only of
6463 support for fast loading into the emulated ROM; to debug, you must use
6464 another protocol, such as standard remote protocol. The usual
6465 sequence is something like
6467 target nrom <netrom-hostname>
6469 target remote <netrom-hostname>:1235
6473 GDB now includes support for the Apple Macintosh, as a host only. It
6474 may be run as either an MPW tool or as a standalone application, and
6475 it can debug through the serial port. All the usual GDB commands are
6476 available, but to the target command, you must supply "serial" as the
6477 device type instead of "/dev/ttyXX". See mpw-README in the main
6478 directory for more information on how to build. The MPW configuration
6479 scripts */mpw-config.in support only a few targets, and only the
6480 mips-idt-ecoff target has been tested.
6484 GDB configuration now uses autoconf. This is not user-visible,
6485 but does simplify configuration and building.
6489 GDB now supports hpux10.
6491 *** Changes in GDB-4.14:
6493 * New native configurations
6495 x86 FreeBSD i[345]86-*-freebsd
6496 x86 NetBSD i[345]86-*-netbsd
6497 NS32k NetBSD ns32k-*-netbsd
6498 Sparc NetBSD sparc-*-netbsd
6502 A29K VxWorks a29k-*-vxworks
6503 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6504 CPU32 EST-300 emulator m68*-*-est*
6505 PowerPC ELF powerpc-*-elf
6508 * Alpha OSF/1 support for procfs
6510 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6511 possible to attach to running processes. As the mounting of the /proc
6512 filesystem is optional on the Alpha, GDB automatically determines
6513 the availability of /proc during startup. This can lead to problems
6514 if /proc is unmounted after GDB has been started.
6516 * Arguments to user-defined commands
6518 User commands may accept up to 10 arguments separated by whitespace.
6519 Arguments are accessed within the user command via $arg0..$arg9. A
6522 print $arg0 + $arg1 + $arg2
6524 To execute the command use:
6527 Defines the command "adder" which prints the sum of its three arguments.
6528 Note the arguments are text substitutions, so they may reference variables,
6529 use complex expressions, or even perform inferior function calls.
6531 * New `if' and `while' commands
6533 This makes it possible to write more sophisticated user-defined
6534 commands. Both commands take a single argument, which is the
6535 expression to evaluate, and must be followed by the commands to
6536 execute, one per line, if the expression is nonzero, the list being
6537 terminated by the word `end'. The `if' command list may include an
6538 `else' word, which causes the following commands to be executed only
6539 if the expression is zero.
6541 * Fortran source language mode
6543 GDB now includes partial support for Fortran 77. It will recognize
6544 Fortran programs and can evaluate a subset of Fortran expressions, but
6545 variables and functions may not be handled correctly. GDB will work
6546 with G77, but does not yet know much about symbols emitted by other
6549 * Better HPUX support
6551 Most debugging facilities now work on dynamic executables for HPPAs
6552 running hpux9 or later. You can attach to running dynamically linked
6553 processes, but by default the dynamic libraries will be read-only, so
6554 for instance you won't be able to put breakpoints in them. To change
6555 that behavior do the following before running the program:
6561 This will cause the libraries to be mapped private and read-write.
6562 To revert to the normal behavior, do this:
6568 You cannot set breakpoints or examine data in the library until after
6569 the library is loaded if the function/data symbols do not have
6572 GDB can now also read debug symbols produced by the HP C compiler on
6573 HPPAs (sorry, no C++, Fortran or 68k support).
6575 * Target byte order now dynamically selectable
6577 You can choose which byte order to use with a target system, via the
6578 commands "set endian big" and "set endian little", and you can see the
6579 current setting by using "show endian". You can also give the command
6580 "set endian auto", in which case GDB will use the byte order
6581 associated with the executable. Currently, only embedded MIPS
6582 configurations support dynamic selection of target byte order.
6584 * New DOS host serial code
6586 This version uses DPMI interrupts to handle buffered I/O, so you
6587 no longer need to run asynctsr when debugging boards connected to
6590 *** Changes in GDB-4.13:
6592 * New "complete" command
6594 This lists all the possible completions for the rest of the line, if it
6595 were to be given as a command itself. This is intended for use by emacs.
6597 * Trailing space optional in prompt
6599 "set prompt" no longer adds a space for you after the prompt you set. This
6600 allows you to set a prompt which ends in a space or one that does not.
6602 * Breakpoint hit counts
6604 "info break" now displays a count of the number of times the breakpoint
6605 has been hit. This is especially useful in conjunction with "ignore"; you
6606 can ignore a large number of breakpoint hits, look at the breakpoint info
6607 to see how many times the breakpoint was hit, then run again, ignoring one
6608 less than that number, and this will get you quickly to the last hit of
6611 * Ability to stop printing at NULL character
6613 "set print null-stop" will cause GDB to stop printing the characters of
6614 an array when the first NULL is encountered. This is useful when large
6615 arrays actually contain only short strings.
6617 * Shared library breakpoints
6619 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6620 breakpoints in shared libraries before the executable is run.
6622 * Hardware watchpoints
6624 There is a new hardware breakpoint for the watch command for sparclite
6625 targets. See gdb/sparclite/hw_breakpoint.note.
6627 Hardware watchpoints are also now supported under GNU/Linux.
6631 Annotations have been added. These are for use with graphical interfaces,
6632 and are still experimental. Currently only gdba.el uses these.
6634 * Improved Irix 5 support
6636 GDB now works properly with Irix 5.2.
6638 * Improved HPPA support
6640 GDB now works properly with the latest GCC and GAS.
6642 * New native configurations
6644 Sequent PTX4 i[34]86-sequent-ptx4
6645 HPPA running OSF/1 hppa*-*-osf*
6646 Atari TT running SVR4 m68*-*-sysv4*
6647 RS/6000 LynxOS rs6000-*-lynxos*
6651 OS/9000 i[34]86-*-os9k
6652 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6655 * Hitachi SH7000 and E7000-PC ICE support
6657 There is now support for communicating with the Hitachi E7000-PC ICE.
6658 This is available automatically when GDB is configured for the SH.
6662 As usual, a variety of small fixes and improvements, both generic
6663 and configuration-specific. See the ChangeLog for more detail.
6665 *** Changes in GDB-4.12:
6667 * Irix 5 is now supported
6671 GDB-4.12 on the HPPA has a number of changes which make it unable
6672 to debug the output from the currently released versions of GCC and
6673 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6674 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6675 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6678 *** Changes in GDB-4.11:
6680 * User visible changes:
6684 The "set remotedebug" option is now consistent between the mips remote
6685 target, remote targets using the gdb-specific protocol, UDI (AMD's
6686 debug protocol for the 29k) and the 88k bug monitor. It is now an
6687 integer specifying a debug level (normally 0 or 1, but 2 means more
6688 debugging info for the mips target).
6690 * DEC Alpha native support
6692 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6693 debug info, but GDB works fairly well with the DEC compiler and should
6694 work with a future GCC release. See the README file for a few
6695 Alpha-specific notes.
6697 * Preliminary thread implementation
6699 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6701 * LynxOS native and target support for 386
6703 This release has been hosted on LynxOS 2.2, and also can be configured
6704 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6707 * Improvements in C++ mangling/demangling.
6709 This release has much better g++ debugging, specifically in name
6710 mangling/demangling, virtual function calls, print virtual table,
6711 call methods, ...etc.
6713 *** Changes in GDB-4.10:
6715 * User visible changes:
6717 Remote debugging using the GDB-specific (`target remote') protocol now
6718 supports the `load' command. This is only useful if you have some
6719 other way of getting the stub to the target system, and you can put it
6720 somewhere in memory where it won't get clobbered by the download.
6722 Filename completion now works.
6724 When run under emacs mode, the "info line" command now causes the
6725 arrow to point to the line specified. Also, "info line" prints
6726 addresses in symbolic form (as well as hex).
6728 All vxworks based targets now support a user settable option, called
6729 vxworks-timeout. This option represents the number of seconds gdb
6730 should wait for responses to rpc's. You might want to use this if
6731 your vxworks target is, perhaps, a slow software simulator or happens
6732 to be on the far side of a thin network line.
6736 This release contains support for using a DEC alpha as a GDB host for
6737 cross debugging. Native alpha debugging is not supported yet.
6740 *** Changes in GDB-4.9:
6744 This is the first GDB release which is accompanied by a matching testsuite.
6745 The testsuite requires installation of dejagnu, which should be available
6746 via ftp from most sites that carry GNU software.
6750 'Cfront' style demangling has had its name changed to 'ARM' style, to
6751 emphasize that it was written from the specifications in the C++ Annotated
6752 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6753 disclaimers, it still generated too much confusion with users attempting to
6754 use gdb with AT&T cfront.
6758 GDB now uses a standard remote interface to a simulator library.
6759 So far, the library contains simulators for the Zilog Z8001/2, the
6760 Hitachi H8/300, H8/500 and Super-H.
6762 * New targets supported
6764 H8/300 simulator h8300-hitachi-hms or h8300hms
6765 H8/500 simulator h8500-hitachi-hms or h8500hms
6766 SH simulator sh-hitachi-hms or sh
6767 Z8000 simulator z8k-zilog-none or z8ksim
6768 IDT MIPS board over serial line mips-idt-ecoff
6770 Cross-debugging to GO32 targets is supported. It requires a custom
6771 version of the i386-stub.c module which is integrated with the
6772 GO32 memory extender.
6774 * New remote protocols
6776 MIPS remote debugging protocol.
6778 * New source languages supported
6780 This version includes preliminary support for Chill, a Pascal like language
6781 used by telecommunications companies. Chill support is also being integrated
6782 into the GNU compiler, but we don't know when it will be publically available.
6785 *** Changes in GDB-4.8:
6787 * HP Precision Architecture supported
6789 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6790 version of this support was available as a set of patches from the
6791 University of Utah. GDB does not support debugging of programs
6792 compiled with the HP compiler, because HP will not document their file
6793 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6794 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6796 Many problems in the preliminary version have been fixed.
6798 * Faster and better demangling
6800 We have improved template demangling and fixed numerous bugs in the GNU style
6801 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6802 character types (wchar_t) are now supported. Demangling of each symbol is now
6803 only done once, and is cached when the symbol table for a file is read in.
6804 This results in a small increase in memory usage for C programs, a moderate
6805 increase in memory usage for C++ programs, and a fantastic speedup in
6808 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6809 from the specifications in the Annotated Reference Manual, which AT&T's
6810 compiler does not actually implement.
6812 * G++ multiple inheritance compiler problem
6814 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6815 inheritance lattices was reworked to properly discover ambiguities. We
6816 recently found an example which causes this new algorithm to fail in a
6817 very subtle way, producing bad debug information for those classes.
6818 The file 'gcc.patch' (in this directory) can be applied to gcc to
6819 circumvent the problem. A future GCC release will contain a complete
6822 The previous G++ debug info problem (mentioned below for the gdb-4.7
6823 release) is fixed in gcc version 2.3.2.
6825 * Improved configure script
6827 The `configure' script will now attempt to guess your system type if
6828 you don't supply a host system type. The old scheme of supplying a
6829 host system triplet is preferable over using this. All the magic is
6830 done in the new `config.guess' script. Examine it for details.
6832 We have also brought our configure script much more in line with the FSF's
6833 version. It now supports the --with-xxx options. In particular,
6834 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6835 The resulting GDB will not be able to read arbitrary object file formats --
6836 only the format ``expected'' to be used on the configured target system.
6837 We hope to make this the default in a future release.
6839 * Documentation improvements
6841 There's new internal documentation on how to modify GDB, and how to
6842 produce clean changes to the code. We implore people to read it
6843 before submitting changes.
6845 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6846 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6847 `info' files are also provided. To build `info' files from scratch,
6848 you will need the latest `makeinfo' release, which will be available in
6849 a future texinfo-X.Y release.
6851 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6852 We're not sure exactly which versions have this problem, but it has
6853 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6854 or better. If that isn't possible, there is a patch in
6855 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6856 around this problem.
6860 GDB now supports array constants that can be used in expressions typed in by
6861 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6862 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6865 The new directory `gdb/sparclite' contains a program that demonstrates
6866 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6868 * New native hosts supported
6870 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6871 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6873 * New targets supported
6875 AMD 29k family via UDI a29k-amd-udi or udi29k
6877 * New file formats supported
6879 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6880 HPUX core files, and SCO 3.2v2 core files.
6884 Attaching to processes now works again; thanks for the many bug reports.
6886 We have also stomped on a bunch of core dumps caused by
6887 printf_filtered("%s") problems.
6889 We eliminated a copyright problem on the rpc and ptrace header files
6890 for VxWorks, which was discovered at the last minute during the 4.7
6891 release. You should now be able to build a VxWorks GDB.
6893 You can now interrupt gdb while an attached process is running. This
6894 will cause the attached process to stop, and give control back to GDB.
6896 We fixed problems caused by using too many file descriptors
6897 for reading symbols from object files and libraries. This was
6898 especially a problem for programs that used many (~100) shared
6901 The `step' command now only enters a subroutine if there is line number
6902 information for the subroutine. Otherwise it acts like the `next'
6903 command. Previously, `step' would enter subroutines if there was
6904 any debugging information about the routine. This avoids problems
6905 when using `cc -g1' on MIPS machines.
6907 * Internal improvements
6909 GDB's internal interfaces have been improved to make it easier to support
6910 debugging of multiple languages in the future.
6912 GDB now uses a common structure for symbol information internally.
6913 Minimal symbols (derived from linkage symbols in object files), partial
6914 symbols (from a quick scan of debug information), and full symbols
6915 contain a common subset of information, making it easier to write
6916 shared code that handles any of them.
6918 * New command line options
6920 We now accept --silent as an alias for --quiet.
6924 The memory-mapped-malloc library is now licensed under the GNU Library
6925 General Public License.
6927 *** Changes in GDB-4.7:
6929 * Host/native/target split
6931 GDB has had some major internal surgery to untangle the support for
6932 hosts and remote targets. Now, when you configure GDB for a remote
6933 target, it will no longer load in all of the support for debugging
6934 local programs on the host. When fully completed and tested, this will
6935 ensure that arbitrary host/target combinations are possible.
6937 The primary conceptual shift is to separate the non-portable code in
6938 GDB into three categories. Host specific code is required any time GDB
6939 is compiled on that host, regardless of the target. Target specific
6940 code relates to the peculiarities of the target, but can be compiled on
6941 any host. Native specific code is everything else: it can only be
6942 built when the host and target are the same system. Child process
6943 handling and core file support are two common `native' examples.
6945 GDB's use of /proc for controlling Unix child processes is now cleaner.
6946 It has been split out into a single module under the `target_ops' vector,
6947 plus two native-dependent functions for each system that uses /proc.
6949 * New hosts supported
6951 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6952 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6953 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6955 * New targets supported
6957 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6958 68030 and CPU32 m68030-*-*, m68332-*-*
6960 * New native hosts supported
6962 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6963 (386bsd is not well tested yet)
6964 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6966 * New file formats supported
6968 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6969 supports reading of `a.out.adobe' object files, which are an a.out
6970 format extended with minimal information about multiple sections.
6974 `show copying' is the same as the old `info copying'.
6975 `show warranty' is the same as `info warrantee'.
6976 These were renamed for consistency. The old commands continue to work.
6978 `info handle' is a new alias for `info signals'.
6980 You can now define pre-command hooks, which attach arbitrary command
6981 scripts to any command. The commands in the hook will be executed
6982 prior to the user's command. You can also create a hook which will be
6983 executed whenever the program stops. See gdb.texinfo.
6987 We now deal with Cfront style name mangling, and can even extract type
6988 info from mangled symbols. GDB can automatically figure out which
6989 symbol mangling style your C++ compiler uses.
6991 Calling of methods and virtual functions has been improved as well.
6995 The crash that occured when debugging Sun Ansi-C compiled binaries is
6996 fixed. This was due to mishandling of the extra N_SO stabs output
6999 We also finally got Ultrix 4.2 running in house, and fixed core file
7000 support, with help from a dozen people on the net.
7002 John M. Farrell discovered that the reason that single-stepping was so
7003 slow on all of the Mips based platforms (primarily SGI and DEC) was
7004 that we were trying to demangle and lookup a symbol used for internal
7005 purposes on every instruction that was being stepped through. Changing
7006 the name of that symbol so that it couldn't be mistaken for a C++
7007 mangled symbol sped things up a great deal.
7009 Rich Pixley sped up symbol lookups in general by getting much smarter
7010 about when C++ symbol mangling is necessary. This should make symbol
7011 completion (TAB on the command line) much faster. It's not as fast as
7012 we'd like, but it's significantly faster than gdb-4.6.
7016 A new user controllable variable 'call_scratch_address' can
7017 specify the location of a scratch area to be used when GDB
7018 calls a function in the target. This is necessary because the
7019 usual method of putting the scratch area on the stack does not work
7020 in systems that have separate instruction and data spaces.
7022 We integrated changes to support the 29k UDI (Universal Debugger
7023 Interface), but discovered at the last minute that we didn't have all
7024 of the appropriate copyright paperwork. We are working with AMD to
7025 resolve this, and hope to have it available soon.
7029 We have sped up the remote serial line protocol, especially for targets
7030 with lots of registers. It now supports a new `expedited status' ('T')
7031 message which can be used in place of the existing 'S' status message.
7032 This allows the remote stub to send only the registers that GDB
7033 needs to make a quick decision about single-stepping or conditional
7034 breakpoints, eliminating the need to fetch the entire register set for
7035 each instruction being stepped through.
7037 The GDB remote serial protocol now implements a write-through cache for
7038 registers, only re-reading the registers if the target has run.
7040 There is also a new remote serial stub for SPARC processors. You can
7041 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7042 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7043 processor with a serial port.
7047 Configure.in files have become much easier to read and modify. A new
7048 `table driven' format makes it more obvious what configurations are
7049 supported, and what files each one uses.
7053 There is a new opcodes library which will eventually contain all of the
7054 disassembly routines and opcode tables. At present, it only contains
7055 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7056 disassembler (binutils/objdump) to share these routines.
7058 The libiberty library is now copylefted under the GNU Library General
7059 Public License. This allows more liberal use, and was done so libg++
7060 can use it. This makes no difference to GDB, since the Library License
7061 grants all the rights from the General Public License.
7065 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7066 reference to the stabs symbol info used by the debugger. It is (as far
7067 as we know) the only published document on this fascinating topic. We
7068 encourage you to read it, compare it to the stabs information on your
7069 system, and send improvements on the document in general (to
7070 bug-gdb@prep.ai.mit.edu).
7072 And, of course, many bugs have been fixed.
7075 *** Changes in GDB-4.6:
7077 * Better support for C++ function names
7079 GDB now accepts as input the "demangled form" of C++ overloaded function
7080 names and member function names, and can do command completion on such names
7081 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7082 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7083 Make use of command completion, it is your friend.
7085 GDB also now accepts a variety of C++ mangled symbol formats. They are
7086 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7087 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7088 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7089 for the list of formats.
7091 * G++ symbol mangling problem
7093 Recent versions of gcc have a bug in how they emit debugging information for
7094 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7095 directory) can be applied to gcc to fix the problem. Alternatively, if you
7096 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7097 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7098 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7101 * New 'maintenance' command
7103 All of the commands related to hacking GDB internals have been moved out of
7104 the main command set, and now live behind the 'maintenance' command. This
7105 can also be abbreviated as 'mt'. The following changes were made:
7107 dump-me -> maintenance dump-me
7108 info all-breakpoints -> maintenance info breakpoints
7109 printmsyms -> maintenance print msyms
7110 printobjfiles -> maintenance print objfiles
7111 printpsyms -> maintenance print psymbols
7112 printsyms -> maintenance print symbols
7114 The following commands are new:
7116 maintenance demangle Call internal GDB demangler routine to
7117 demangle a C++ link name and prints the result.
7118 maintenance print type Print a type chain for a given symbol
7120 * Change to .gdbinit file processing
7122 We now read the $HOME/.gdbinit file before processing the argv arguments
7123 (e.g. reading symbol files or core files). This allows global parameters to
7124 be set, which will apply during the symbol reading. The ./.gdbinit is still
7125 read after argv processing.
7127 * New hosts supported
7129 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7131 GNU/Linux support i386-unknown-linux or linux
7133 We are also including code to support the HP/PA running BSD and HPUX. This
7134 is almost guaranteed not to work, as we didn't have time to test or build it
7135 for this release. We are including it so that the more adventurous (or
7136 masochistic) of you can play with it. We also had major problems with the
7137 fact that the compiler that we got from HP doesn't support the -g option.
7140 * New targets supported
7142 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7144 * More smarts about finding #include files
7146 GDB now remembers the compilation directory for all include files, and for
7147 all files from which C is generated (like yacc and lex sources). This
7148 greatly improves GDB's ability to find yacc/lex sources, and include files,
7149 especially if you are debugging your program from a directory different from
7150 the one that contains your sources.
7152 We also fixed a bug which caused difficulty with listing and setting
7153 breakpoints in include files which contain C code. (In the past, you had to
7154 try twice in order to list an include file that you hadn't looked at before.)
7156 * Interesting infernals change
7158 GDB now deals with arbitrary numbers of sections, where the symbols for each
7159 section must be relocated relative to that section's landing place in the
7160 target's address space. This work was needed to support ELF with embedded
7161 stabs used by Solaris-2.0.
7163 * Bug fixes (of course!)
7165 There have been loads of fixes for the following things:
7166 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7167 i960, stabs, DOS(GO32), procfs, etc...
7169 See the ChangeLog for details.
7171 *** Changes in GDB-4.5:
7173 * New machines supported (host and target)
7175 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7177 SGI Irix-4.x mips-sgi-irix4 or iris4
7179 * New malloc package
7181 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7182 Mmalloc is capable of handling mutiple heaps of memory. It is also
7183 capable of saving a heap to a file, and then mapping it back in later.
7184 This can be used to greatly speedup the startup of GDB by using a
7185 pre-parsed symbol table which lives in a mmalloc managed heap. For
7186 more details, please read mmalloc/mmalloc.texi.
7190 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7191 'help info proc' for details.
7193 * MIPS ecoff symbol table format
7195 The code that reads MIPS symbol table format is now supported on all hosts.
7196 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7199 * File name changes for MS-DOS
7201 Many files in the config directories have been renamed to make it easier to
7202 support GDB on MS-DOSe systems (which have very restrictive file name
7203 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7204 environment) is close to working but has some remaining problems. Note
7205 that debugging of DOS programs is not supported, due to limitations
7206 in the ``operating system'', but it can be used to host cross-debugging.
7208 * Cross byte order fixes
7210 Many fixes have been made to support cross debugging of Sparc and MIPS
7211 targets from hosts whose byte order differs.
7213 * New -mapped and -readnow options
7215 If memory-mapped files are available on your system through the 'mmap'
7216 system call, you can use the -mapped option on the `file' or
7217 `symbol-file' commands to cause GDB to write the symbols from your
7218 program into a reusable file. If the program you are debugging is
7219 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7220 Future GDB debugging sessions will notice the presence of this file,
7221 and will quickly map in symbol information from it, rather than reading
7222 the symbol table from the executable program. Using the '-mapped'
7223 option in a GDB `file' or `symbol-file' command has the same effect as
7224 starting GDB with the '-mapped' command-line option.
7226 You can cause GDB to read the entire symbol table immediately by using
7227 the '-readnow' option with any of the commands that load symbol table
7228 information (or on the GDB command line). This makes the command
7229 slower, but makes future operations faster.
7231 The -mapped and -readnow options are typically combined in order to
7232 build a `fred.syms' file that contains complete symbol information.
7233 A simple GDB invocation to do nothing but build a `.syms' file for future
7236 gdb -batch -nx -mapped -readnow programname
7238 The `.syms' file is specific to the host machine on which GDB is run.
7239 It holds an exact image of GDB's internal symbol table. It cannot be
7240 shared across multiple host platforms.
7242 * longjmp() handling
7244 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7245 siglongjmp() without losing control. This feature has not yet been ported to
7246 all systems. It currently works on many 386 platforms, all MIPS-based
7247 platforms (SGI, DECstation, etc), and Sun3/4.
7251 Preliminary work has been put in to support the new Solaris OS from Sun. At
7252 this time, it can control and debug processes, but it is not capable of
7257 As always, many many bug fixes. The major areas were with g++, and mipsread.
7258 People using the MIPS-based platforms should experience fewer mysterious
7259 crashes and trashed symbol tables.
7261 *** Changes in GDB-4.4:
7263 * New machines supported (host and target)
7265 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7267 BSD Reno on Vax vax-dec-bsd
7268 Ultrix on Vax vax-dec-ultrix
7270 * New machines supported (target)
7272 AMD 29000 embedded, using EBMON a29k-none-none
7276 GDB continues to improve its handling of C++. `References' work better.
7277 The demangler has also been improved, and now deals with symbols mangled as
7278 per the Annotated C++ Reference Guide.
7280 GDB also now handles `stabs' symbol information embedded in MIPS
7281 `ecoff' symbol tables. Since the ecoff format was not easily
7282 extensible to handle new languages such as C++, this appeared to be a
7283 good way to put C++ debugging info into MIPS binaries. This option
7284 will be supported in the GNU C compiler, version 2, when it is
7287 * New features for SVR4
7289 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7290 shared libraries. Debugging dynamically linked programs should present
7291 only minor differences from debugging statically linked programs.
7293 The `info proc' command will print out information about any process
7294 on an SVR4 system (including the one you are debugging). At the moment,
7295 it prints the address mappings of the process.
7297 If you bring up GDB on another SVR4 system, please send mail to
7298 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7300 * Better dynamic linking support in SunOS
7302 Reading symbols from shared libraries which contain debugging symbols
7303 now works properly. However, there remain issues such as automatic
7304 skipping of `transfer vector' code during function calls, which
7305 make it harder to debug code in a shared library, than to debug the
7306 same code linked statically.
7310 GDB is now using the latest `getopt' routines from the FSF. This
7311 version accepts the -- prefix for options with long names. GDB will
7312 continue to accept the old forms (-option and +option) as well.
7313 Various single letter abbreviations for options have been explicity
7314 added to the option table so that they won't get overshadowed in the
7315 future by other options that begin with the same letter.
7319 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7320 Many assorted bugs have been handled. Many more remain to be handled.
7321 See the various ChangeLog files (primarily in gdb and bfd) for details.
7324 *** Changes in GDB-4.3:
7326 * New machines supported (host and target)
7328 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7329 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7330 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7332 * Almost SCO Unix support
7334 We had hoped to support:
7335 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7336 (except for core file support), but we discovered very late in the release
7337 that it has problems with process groups that render gdb unusable. Sorry
7338 about that. I encourage people to fix it and post the fixes.
7340 * Preliminary ELF and DWARF support
7342 GDB can read ELF object files on System V Release 4, and can handle
7343 debugging records for C, in DWARF format, in ELF files. This support
7344 is preliminary. If you bring up GDB on another SVR4 system, please
7345 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7350 GDB now uses the latest `readline' library. One user-visible change
7351 is that two tabs will list possible command completions, which previously
7352 required typing M-? (meta-question mark, or ESC ?).
7356 The `stepi' bug that many of you noticed has been squashed.
7357 Many bugs in C++ have been handled. Many more remain to be handled.
7358 See the various ChangeLog files (primarily in gdb and bfd) for details.
7360 * State of the MIPS world (in case you wondered):
7362 GDB can understand the symbol tables emitted by the compilers
7363 supplied by most vendors of MIPS-based machines, including DEC. These
7364 symbol tables are in a format that essentially nobody else uses.
7366 Some versions of gcc come with an assembler post-processor called
7367 mips-tfile. This program is required if you want to do source-level
7368 debugging of gcc-compiled programs. I believe FSF does not ship
7369 mips-tfile with gcc version 1, but it will eventually come with gcc
7372 Debugging of g++ output remains a problem. g++ version 1.xx does not
7373 really support it at all. (If you're lucky, you should be able to get
7374 line numbers and stack traces to work, but no parameters or local
7375 variables.) With some work it should be possible to improve the
7378 When gcc version 2 is released, you will have somewhat better luck.
7379 However, even then you will get confusing results for inheritance and
7382 We will eventually provide full debugging of g++ output on
7383 DECstations. This will probably involve some kind of stabs-in-ecoff
7384 encapulation, but the details have not been worked out yet.
7387 *** Changes in GDB-4.2:
7389 * Improved configuration
7391 Only one copy of `configure' exists now, and it is not self-modifying.
7392 Porting BFD is simpler.
7396 The `step' and `next' commands now only stop at the first instruction
7397 of a source line. This prevents the multiple stops that used to occur
7398 in switch statements, for-loops, etc. `Step' continues to stop if a
7399 function that has debugging information is called within the line.
7403 Lots of small bugs fixed. More remain.
7405 * New host supported (not target)
7407 Intel 386 PC clone running Mach i386-none-mach
7410 *** Changes in GDB-4.1:
7412 * Multiple source language support
7414 GDB now has internal scaffolding to handle several source languages.
7415 It determines the type of each source file from its filename extension,
7416 and will switch expression parsing and number formatting to match the
7417 language of the function in the currently selected stack frame.
7418 You can also specifically set the language to be used, with
7419 `set language c' or `set language modula-2'.
7423 GDB now has preliminary support for the GNU Modula-2 compiler,
7424 currently under development at the State University of New York at
7425 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7426 continue through the fall of 1991 and into 1992.
7428 Other Modula-2 compilers are currently not supported, and attempting to
7429 debug programs compiled with them will likely result in an error as the
7430 symbol table is read. Feel free to work on it, though!
7432 There are hooks in GDB for strict type checking and range checking,
7433 in the `Modula-2 philosophy', but they do not currently work.
7437 GDB can now write to executable and core files (e.g. patch
7438 a variable's value). You must turn this switch on, specify
7439 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7440 by assigning a new value to a variable. Modifications take
7443 * Automatic SunOS shared library reading
7445 When you run your program, GDB automatically determines where its
7446 shared libraries (if any) have been loaded, and reads their symbols.
7447 The `share' command is no longer needed. This also works when
7448 examining core files.
7452 You can specify the number of lines that the `list' command shows.
7455 * New machines supported (host and target)
7457 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7458 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7459 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7461 * New hosts supported (not targets)
7463 IBM RT/PC: romp-ibm-aix or rtpc
7465 * New targets supported (not hosts)
7467 AMD 29000 embedded with COFF a29k-none-coff
7468 AMD 29000 embedded with a.out a29k-none-aout
7469 Ultracomputer remote kernel debug a29k-nyu-kern
7471 * New remote interfaces
7477 *** Changes in GDB-4.0:
7481 Wide output is wrapped at good places to make the output more readable.
7483 Gdb now supports cross-debugging from a host machine of one type to a
7484 target machine of another type. Communication with the target system
7485 is over serial lines. The ``target'' command handles connecting to the
7486 remote system; the ``load'' command will download a program into the
7487 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7488 also supports debugging of realtime processes running under VxWorks,
7489 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7490 stub on the target system.
7492 New CPUs supported include the AMD 29000 and Intel 960.
7494 GDB now reads object files and symbol tables via a ``binary file''
7495 library, which allows a single copy of GDB to debug programs of multiple
7496 object file types such as a.out and coff.
7498 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7499 refcard.dvi and refcard.ps are available to format it).
7502 * Control-Variable user interface simplified
7504 All variables that control the operation of the debugger can be set
7505 by the ``set'' command, and displayed by the ``show'' command.
7507 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7508 ``Show prompt'' produces the response:
7509 Gdb's prompt is new-gdb=>.
7511 What follows are the NEW set commands. The command ``help set'' will
7512 print a complete list of old and new set commands. ``help set FOO''
7513 will give a longer description of the variable FOO. ``show'' will show
7514 all of the variable descriptions and their current settings.
7516 confirm on/off: Enables warning questions for operations that are
7517 hard to recover from, e.g. rerunning the program while
7518 it is already running. Default is ON.
7520 editing on/off: Enables EMACS style command line editing
7521 of input. Previous lines can be recalled with
7522 control-P, the current line can be edited with control-B,
7523 you can search for commands with control-R, etc.
7526 history filename NAME: NAME is where the gdb command history
7527 will be stored. The default is .gdb_history,
7528 or the value of the environment variable
7531 history size N: The size, in commands, of the command history. The
7532 default is 256, or the value of the environment variable
7535 history save on/off: If this value is set to ON, the history file will
7536 be saved after exiting gdb. If set to OFF, the
7537 file will not be saved. The default is OFF.
7539 history expansion on/off: If this value is set to ON, then csh-like
7540 history expansion will be performed on
7541 command line input. The default is OFF.
7543 radix N: Sets the default radix for input and output. It can be set
7544 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7545 in the current radix, so "set radix 10" is always a no-op.
7547 height N: This integer value is the number of lines on a page. Default
7548 is 24, the current `stty rows'' setting, or the ``li#''
7549 setting from the termcap entry matching the environment
7552 width N: This integer value is the number of characters on a line.
7553 Default is 80, the current `stty cols'' setting, or the ``co#''
7554 setting from the termcap entry matching the environment
7557 Note: ``set screensize'' is obsolete. Use ``set height'' and
7558 ``set width'' instead.
7560 print address on/off: Print memory addresses in various command displays,
7561 such as stack traces and structure values. Gdb looks
7562 more ``symbolic'' if you turn this off; it looks more
7563 ``machine level'' with it on. Default is ON.
7565 print array on/off: Prettyprint arrays. New convenient format! Default
7568 print demangle on/off: Print C++ symbols in "source" form if on,
7571 print asm-demangle on/off: Same, for assembler level printouts
7574 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7577 * Support for Epoch Environment.
7579 The epoch environment is a version of Emacs v18 with windowing. One
7580 new command, ``inspect'', is identical to ``print'', except that if you
7581 are running in the epoch environment, the value is printed in its own
7585 * Support for Shared Libraries
7587 GDB can now debug programs and core files that use SunOS shared libraries.
7588 Symbols from a shared library cannot be referenced
7589 before the shared library has been linked with the program (this
7590 happens after you type ``run'' and before the function main() is entered).
7591 At any time after this linking (including when examining core files
7592 from dynamically linked programs), gdb reads the symbols from each
7593 shared library when you type the ``sharedlibrary'' command.
7594 It can be abbreviated ``share''.
7596 sharedlibrary REGEXP: Load shared object library symbols for files
7597 matching a unix regular expression. No argument
7598 indicates to load symbols for all shared libraries.
7600 info sharedlibrary: Status of loaded shared libraries.
7605 A watchpoint stops execution of a program whenever the value of an
7606 expression changes. Checking for this slows down execution
7607 tremendously whenever you are in the scope of the expression, but is
7608 quite useful for catching tough ``bit-spreader'' or pointer misuse
7609 problems. Some machines such as the 386 have hardware for doing this
7610 more quickly, and future versions of gdb will use this hardware.
7612 watch EXP: Set a watchpoint (breakpoint) for an expression.
7614 info watchpoints: Information about your watchpoints.
7616 delete N: Deletes watchpoint number N (same as breakpoints).
7617 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7618 enable N: Re-enables watchpoint number N (same as breakpoints).
7621 * C++ multiple inheritance
7623 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7626 * C++ exception handling
7628 Gdb now supports limited C++ exception handling. Besides the existing
7629 ability to breakpoint on an exception handler, gdb can breakpoint on
7630 the raising of an exception (before the stack is peeled back to the
7633 catch FOO: If there is a FOO exception handler in the dynamic scope,
7634 set a breakpoint to catch exceptions which may be raised there.
7635 Multiple exceptions (``catch foo bar baz'') may be caught.
7637 info catch: Lists all exceptions which may be caught in the
7638 current stack frame.
7641 * Minor command changes
7643 The command ``call func (arg, arg, ...)'' now acts like the print
7644 command, except it does not print or save a value if the function's result
7645 is void. This is similar to dbx usage.
7647 The ``up'' and ``down'' commands now always print the frame they end up
7648 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7649 frames without printing.
7651 * New directory command
7653 'dir' now adds directories to the FRONT of the source search path.
7654 The path starts off empty. Source files that contain debug information
7655 about the directory in which they were compiled can be found even
7656 with an empty path; Sun CC and GCC include this information. If GDB can't
7657 find your source file in the current directory, type "dir .".
7659 * Configuring GDB for compilation
7661 For normal use, type ``./configure host''. See README or gdb.texinfo
7664 GDB now handles cross debugging. If you are remotely debugging between
7665 two different machines, type ``./configure host -target=targ''.
7666 Host is the machine where GDB will run; targ is the machine
7667 where the program that you are debugging will run.