1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.3
6 * 'thread-exited' event is now available in the annotations interface.
8 * New built-in convenience variables $_gdb_major and $_gdb_minor
9 provide the GDB version. They are handy for conditionally using
10 features available only in or since specific GDB versions, in
11 scripts that should work error-free with many different versions,
12 such as in system-wide init files.
14 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
15 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
16 of the GDB settings and the GDB maintenance settings. They are handy
17 for changing the logic of user defined commands depending on the
20 * GDB now supports Thread Local Storage (TLS) variables on several
21 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
22 architectures require kernel changes. TLS is not yet supported for
23 amd64 and i386 process core dumps.
25 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
26 addresses that required unmasking are shown in the backtrace with the
29 * Two new convenience functions $_cimag and $_creal that extract the
30 imaginary and real parts respectively from complex numbers.
32 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
33 provide the exitcode or exit status of the shell commands launched by
34 GDB commands such as "shell", "pipe" and "make".
36 * The RX port now supports XML target descriptions.
38 * GDB now shows the Ada task names at more places, e.g. in task switching
41 * GDB can now be compiled with Python 3 on Windows.
43 * New convenience variable $_ada_exception holds the address of the
44 Ada exception being thrown. This is set by Ada-related catchpoints.
46 * GDB can now place breakpoints on nested functions and subroutines in
47 Fortran code. The '::' operator can be used between parent and
48 child scopes when placing breakpoints, for example:
50 (gdb) break outer_function::inner_function
52 The 'outer_function::' prefix is only needed if 'inner_function' is
53 not visible in the current scope.
55 * In addition to the system-wide gdbinit file, if configured with
56 --with-system-gdbinit-dir, GDB will now also load files in that directory
57 as system gdbinit files, unless the -nx or -n flag is provided. Files
58 with extensions .gdb, .py and .scm are supported as long as GDB was
59 compiled with support for that language.
63 ** The gdb.Value type has a new method 'format_string' which returns a
64 string representing the value. The formatting is controlled by the
65 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
66 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
67 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
69 ** gdb.Type has a new property 'objfile' which returns the objfile the
72 ** The frame information printed by the python frame filtering code
73 is now consistent with what the 'backtrace' command prints when
74 there are no filters, or when the 'backtrace' '-no-filters' option
77 ** The new function gdb.lookup_static_symbol can be used to look up
78 symbols with static linkage.
80 ** The new function gdb.lookup_static_symbols can be used to look up
81 all static symbols with static linkage.
83 ** gdb.Objfile has new methods 'lookup_global_symbol' and
84 'lookup_static_symbol' to lookup a symbol from this objfile only.
86 ** gdb.Block now supports the dictionary syntax for accessing symbols in
87 this block (e.g. block['local_variable']).
91 | [COMMAND] | SHELL_COMMAND
92 | -d DELIM COMMAND DELIM SHELL_COMMAND
93 pipe [COMMAND] | SHELL_COMMAND
94 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
95 Executes COMMAND and sends its output to SHELL_COMMAND.
96 With no COMMAND, repeat the last executed command
97 and send its output to SHELL_COMMAND.
99 with SETTING [VALUE] [-- COMMAND]
100 w SETTING [VALUE] [-- COMMAND]
101 Temporarily set SETTING, run COMMAND, and restore SETTING.
102 Usage: with SETTING -- COMMAND
103 With no COMMAND, repeats the last executed command.
104 SETTING is any GDB setting you can change with the "set"
105 subcommands. For example, 'with language c -- print someobj'
106 temporarily switches to the C language in order to print someobj.
107 Settings can be combined: 'w lang c -- w print elements unlimited --
108 usercmd' switches to the C language and runs usercmd with no limit
109 of array elements to print.
111 maint with SETTING [VALUE] [-- COMMAND]
112 Like "with", but works with "maintenance set" settings.
114 set may-call-functions [on|off]
115 show may-call-functions
116 This controls whether GDB will attempt to call functions in
117 the program, such as with expressions in the print command. It
118 defaults to on. Calling functions in the program being debugged
119 can have undesired side effects. It is now possible to forbid
120 such function calls. If function calls are forbidden, GDB will throw
121 an error when a command (such as print expression) calls a function
124 set print finish [on|off]
126 This controls whether the `finish' command will display the value
127 that is returned by the current function. When `off', the value is
128 still entered into the value history, but it is not printed. The
133 Allows deeply nested structures to be simplified when printing by
134 replacing deeply nested parts (beyond the max-depth) with ellipses.
135 The default max-depth is 20, but this can be set to unlimited to get
136 the old behavior back.
138 set logging debugredirect [on|off]
139 By default, GDB debug output will go to both the terminal and the logfile.
140 Set if you want debug output to go only to the log file.
142 set style title foreground COLOR
143 set style title background COLOR
144 set style title intensity VALUE
145 Control the styling of titles.
147 set style highlight foreground COLOR
148 set style highlight background COLOR
149 set style highlight intensity VALUE
150 Control the styling of highlightings.
152 maint set test-settings KIND
153 maint show test-settings KIND
154 A set of commands used by the testsuite for exercising the settings
157 maint set tui-resize-message [on|off]
158 maint show tui-resize-message
159 Control whether GDB prints a message each time the terminal is
160 resized when in TUI mode. This is primarily useful for testing the
163 set print frame-info [short-location|location|location-and-address
164 |source-and-location|source-line|auto]
165 show print frame-info
166 This controls what frame information is printed by the commands printing
167 a frame. This setting will e.g. influence the behaviour of 'backtrace',
168 'frame', 'stepi'. The python frame filtering also respect this setting.
169 The 'backtrace' '-frame-info' option can override this global setting.
171 info modules [-q] [REGEXP]
172 Return a list of Fortran modules matching REGEXP, or all modules if
175 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
176 Return a list of functions within all modules, grouped by module.
177 The list of functions can be restricted with the optional regular
178 expressions. MODULE_REGEXP matches against the module name,
179 TYPE_REGEXP matches against the function type signature, and REGEXP
180 matches against the function name.
182 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
183 Return a list of variables within all modules, grouped by module.
184 The list of variables can be restricted with the optional regular
185 expressions. MODULE_REGEXP matches against the module name,
186 TYPE_REGEXP matches against the variable type, and REGEXP matches
187 against the variable name.
189 set debug remote-packet-max-chars
190 show debug remote-packet-max-chars
191 Controls the number of characters to output in a remote packet when using
193 The default is 512 bytes.
198 The "help" command uses the title style to enhance the
199 readibility of its output by styling the classes and
203 Similarly to "help", the "apropos" command also uses the
204 title style for the command names. "apropos" accepts now
205 a flag "-v" (verbose) to show the full documentation
206 of matching commands and to use the highlight style to mark
207 the documentation parts matching REGEXP.
211 The GDB printf and eval commands can now print C-style and Ada-style
212 string convenience variables without calling functions in the program.
213 This allows to do formatted printing of strings without having
214 a running inferior, or when debugging a core dump.
216 info sources [-dirname | -basename] [--] [REGEXP]
217 This command has now optional arguments to only print the files
218 whose names match REGEXP. The arguments -dirname and -basename
219 allow to restrict matching respectively to the dirname and basename
223 The "show style" and its subcommands are now styling
224 a style name in their output using its own style, to help
225 the user visualize the different styles.
227 set print frame-arguments
228 The new value 'presence' indicates to only indicate the presence of
229 arguments using ..., instead of printing argument names and values.
231 set print raw-frame-arguments
232 show print raw-frame-arguments
234 These commands replace the similarly-named "set/show print raw
235 frame-arguments" commands (now with a dash instead of a space). The
236 old commands are now deprecated and may be removed in a future
239 maint test-options require-delimiter
240 maint test-options unknown-is-error
241 maint test-options unknown-is-operand
242 maint show test-options-completion-result
243 Commands used by the testsuite to validate the command options
246 focus, winheight, +, -, >, <
247 These commands are now case-sensitive.
249 * New command options, command completion
251 GDB now has a standard infrastructure to support dash-style command
252 options ('-OPT'). One benefit is that commands that use it can
253 easily support completion of command line arguments. Try "CMD
254 -[TAB]" or "help CMD" to find options supported by a command. Over
255 time, we intend to migrate most commands to this infrastructure. A
256 number of commands got support for new command options in this
259 ** The "print" and "compile print" commands now support a number of
260 options that allow overriding relevant global print settings as
261 set by "set print" subcommands:
265 -array-indexes [on|off]
266 -elements NUMBER|unlimited
270 -repeats NUMBER|unlimited
271 -static-members [on|off]
276 Note that because the "print"/"compile print" commands accept
277 arbitrary expressions which may look like options (including
278 abbreviations), if you specify any command option, then you must
279 use a double dash ("--") to mark the end of argument processing.
281 ** The "backtrace" command now supports a number of options that
282 allow overriding relevant global print settings as set by "set
283 backtrace" and "set print" subcommands:
285 -entry-values no|only|preferred|if-needed|both|compact|default
286 -frame-arguments all|scalars|none
287 -raw-frame-arguments [on|off]
288 -frame-info auto|source-line|location|source-and-location
289 |location-and-address|short-location
293 In addition, the full/no-filters/hide qualifiers are now also
294 exposed as command options too:
300 ** The "frame apply", "tfaas" and "faas" commands similarly now
301 support the following options:
306 ** The new "info sources" options -dirname and -basename options
307 are using the standard '-OPT' infrastructure.
309 All options above can also be abbreviated. The argument of boolean
310 (on/off) options can be 0/1 too, and also the argument is assumed
311 "on" if omitted. This allows writing compact command invocations,
314 (gdb) p -r -p -o 0 -- *myptr
316 The above is equivalent to:
318 (gdb) print -raw -pretty -object off -- *myptr
320 ** The "info types" command now supports the '-q' flag to disable
321 printing of some header information in a similar fashion to "info
322 variables" and "info functions".
324 ** The "info variables", "info functions", and "whereis" commands
325 now take a '-n' flag that excludes non-debug symbols (symbols
326 from the symbol table, not from the debug info such as DWARF)
329 * Completion improvements
331 ** GDB can now complete the options of the "thread apply all" and
332 "taas" commands, and their "-ascending" option can now be
335 ** GDB can now complete the options of the "info threads", "info
336 functions", "info variables", "info locals", and "info args"
339 ** GDB can now complete the options of the "compile file" and
340 "compile code" commands. The "compile file" command now
341 completes on filenames.
343 ** GDB can now complete the backtrace command's
344 "full/no-filters/hide" qualifiers.
346 * In settings, you can now abbreviate "unlimited".
348 E.g., "set print elements u" is now equivalent to "set print
354 This lists all the possible completions for the rest of the line, if it
355 were to be given as a command itself. This is intended for use by MI
356 frontends in cases when separate CLI and MI channels cannot be used.
358 -catch-throw, -catch-rethrow, and -catch-catch
359 These can be used to catch C++ exceptions in a similar fashion to
360 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
364 ** The default version of the MI interpreter is now 3 (-i=mi3).
366 ** The output of information about multi-location breakpoints (which is
367 syntactically incorrect in MI 2) has changed in MI 3. This affects
368 the following commands and events:
372 - =breakpoint-created
373 - =breakpoint-modified
375 The -fix-multi-location-breakpoint-output command can be used to enable
376 this behavior with previous MI versions.
378 ** Backtraces and frames include a new optional field addr_flags which is
379 given after the addr field. On AArch64 this contains PAC if the address
380 has been masked in the frame. On all other targets the field is not
385 The testsuite now creates the files gdb.cmd (containing the arguments
386 used to launch GDB) and gdb.in (containing all the commands sent to
387 GDB) in the output directory for each test script. Multiple invocations
388 are appended with .1, .2, .3 etc.
390 * Building GDB and GDBserver now requires GNU make >= 3.82.
392 Using another implementation of the make program or an earlier version of
393 GNU make to build GDB or GDBserver is not supported.
395 * Building GDB now requires GNU readline >= 7.0.
397 GDB now bundles GNU readline 8.0, but if you choose to use
398 --with-system-readline, only readline >= 7.0 can be used.
400 * The TUI SingleKey keymap is now named "SingleKey". This can be used
401 from .inputrc to bind keys in this keymap. This feature is only
402 available when gdb is built against GNU readline 8.0 or later.
404 * Removed targets and native configurations
406 GDB no longer supports debugging the Cell Broadband Engine. This includes
407 both debugging standalone Cell/B.E. SPU applications and integrated debugging
408 of Cell/B.E. applications that use both the PPU and SPU architectures.
414 * Removed targets and native configurations
416 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
419 *** Changes in GDB 8.3
421 * GDB and GDBserver now support access to additional registers on
422 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
425 * GDB now has experimental support for the compilation and injection of
426 C++ source code into the inferior. This beta release does not include
427 support for several language features, such as templates, constructors,
430 This feature requires GCC 7.1 or higher built with libcp1.so
433 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
434 can be passed using the '[ADDRESS]:PORT' notation, or the regular
435 'ADDRESS:PORT' method.
437 * DWARF index cache: GDB can now automatically save indices of DWARF
438 symbols on disk to speed up further loading of the same binaries.
440 * Ada task switching is now supported on aarch64-elf targets when
441 debugging a program using the Ravenscar Profile. For more information,
442 see the "Tasking Support when using the Ravenscar Profile" section
443 in the GDB user manual.
445 * GDB in batch mode now exits with status 1 if the last command to be
448 * The RISC-V target now supports target descriptions.
450 * System call catchpoints now support system call aliases on FreeBSD.
451 When the ABI of a system call changes in FreeBSD, this is
452 implemented by leaving a compatibility system call using the old ABI
453 at the existing number and allocating a new system call number for
454 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
455 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
456 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
457 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
458 so that a system call catchpoint for the 'kevent' system call will
459 catch invocations of both the 'kevent' and 'freebsd11_kevent'
460 binaries. This ensures that 'kevent' system calls are caught for
461 binaries using either the old or new ABIs.
463 * Terminal styling is now available for the CLI and the TUI. GNU
464 Source Highlight can additionally be used to provide styling of
465 source code snippets. See the "set style" commands, below, for more
468 * Removed support for old demangling styles arm, edg, gnu, hp and
473 set debug compile-cplus-types
474 show debug compile-cplus-types
475 Control the display of debug output about type conversion in the
476 C++ compile feature. Commands have no effect while compiliong
481 Control whether debug output about files/functions skipping is
484 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
485 Apply a command to some frames.
486 FLAG arguments allow to control what output to produce and how to handle
487 errors raised when applying COMMAND to a frame.
490 Apply a command to all threads (ignoring errors and empty output).
491 Shortcut for 'thread apply all -s COMMAND'.
494 Apply a command to all frames (ignoring errors and empty output).
495 Shortcut for 'frame apply all -s COMMAND'.
498 Apply a command to all frames of all threads (ignoring errors and empty
500 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
502 maint set dwarf unwinders (on|off)
503 maint show dwarf unwinders
504 Control whether DWARF unwinders can be used.
507 Display a list of open files for a process.
511 Changes to the "frame", "select-frame", and "info frame" CLI commands.
512 These commands all now take a frame specification which
513 is either a frame level, or one of the keywords 'level', 'address',
514 'function', or 'view' followed by a parameter. Selecting a frame by
515 address, or viewing a frame outside the current backtrace now
516 requires the use of a keyword. Selecting a frame by level is
517 unchanged. The MI comment "-stack-select-frame" is unchanged.
519 target remote FILENAME
520 target extended-remote FILENAME
521 If FILENAME is a Unix domain socket, GDB will attempt to connect
522 to this socket instead of opening FILENAME as a character device.
524 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
525 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
526 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
527 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
528 These commands can now print only the searched entities
529 matching the provided regexp(s), giving a condition
530 on the entity names or entity types. The flag -q disables
531 printing headers or informations messages.
537 These commands now determine the syntax for the shown entities
538 according to the language chosen by `set language'. In particular,
539 `set language auto' means to automatically choose the language of
542 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
543 The 'thread apply' command accepts new FLAG arguments.
544 FLAG arguments allow to control what output to produce and how to handle
545 errors raised when applying COMMAND to a thread.
547 set tui tab-width NCHARS
548 show tui tab-width NCHARS
549 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
551 set style enabled [on|off]
553 Enable or disable terminal styling. Styling is enabled by default
554 on most hosts, but disabled by default when in batch mode.
556 set style sources [on|off]
558 Enable or disable source code styling. Source code styling is
559 enabled by default, but only takes effect if styling in general is
560 enabled, and if GDB was linked with GNU Source Highlight.
562 set style filename foreground COLOR
563 set style filename background COLOR
564 set style filename intensity VALUE
565 Control the styling of file names.
567 set style function foreground COLOR
568 set style function background COLOR
569 set style function intensity VALUE
570 Control the styling of function names.
572 set style variable foreground COLOR
573 set style variable background COLOR
574 set style variable intensity VALUE
575 Control the styling of variable names.
577 set style address foreground COLOR
578 set style address background COLOR
579 set style address intensity VALUE
580 Control the styling of addresses.
584 ** The '-data-disassemble' MI command now accepts an '-a' option to
585 disassemble the whole function surrounding the given program
586 counter value or function name. Support for this feature can be
587 verified by using the "-list-features" command, which should
588 contain "data-disassemble-a-option".
590 ** Command responses and notifications that include a frame now include
591 the frame's architecture in a new "arch" attribute.
593 * New native configurations
595 GNU/Linux/RISC-V riscv*-*-linux*
596 FreeBSD/riscv riscv*-*-freebsd*
600 GNU/Linux/RISC-V riscv*-*-linux*
602 CSKY GNU/LINUX csky*-*-linux
603 FreeBSD/riscv riscv*-*-freebsd*
605 GNU/Linux/OpenRISC or1k*-*-linux*
609 GDB no longer supports native debugging on versions of MS-Windows
614 ** GDB no longer supports Python versions less than 2.6.
616 ** The gdb.Inferior type has a new 'progspace' property, which is the program
617 space associated to that inferior.
619 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
620 of objfiles associated to that program space.
622 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
623 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
626 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
627 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
628 correct and did not work properly.
630 ** The gdb.Value type has a new constructor, which is used to construct a
631 gdb.Value from a Python buffer object and a gdb.Type.
637 Enable or disable the undefined behavior sanitizer. This is
638 disabled by default, but passing --enable-ubsan=yes or
639 --enable-ubsan=auto to configure will enable it. Enabling this can
640 cause a performance penalty. The undefined behavior sanitizer was
641 first introduced in GCC 4.9.
643 *** Changes in GDB 8.2
645 * The 'set disassembler-options' command now supports specifying options
648 * The 'symbol-file' command now accepts an '-o' option to add a relative
649 offset to all sections.
651 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
652 a relative offset to all sections, but it allows to override the load
653 address of individual sections using '-s'.
655 * The 'add-symbol-file' command no longer requires the second argument
656 (address of the text section).
658 * The endianness used with the 'set endian auto' mode in the absence of
659 an executable selected for debugging is now the last endianness chosen
660 either by one of the 'set endian big' and 'set endian little' commands
661 or by inferring from the last executable used, rather than the startup
664 * The pager now allows a "c" response, meaning to disable the pager
665 for the rest of the current command.
667 * The commands 'info variables/functions/types' now show the source line
668 numbers of symbol definitions when available.
670 * 'info proc' now works on running processes on FreeBSD systems and core
671 files created on FreeBSD systems.
673 * C expressions can now use _Alignof, and C++ expressions can now use
676 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
677 the vector length while the process is running.
683 Control display of debugging info regarding the FreeBSD native target.
685 set|show varsize-limit
686 This new setting allows the user to control the maximum size of Ada
687 objects being printed when those objects have a variable type,
688 instead of that maximum size being hardcoded to 65536 bytes.
690 set|show record btrace cpu
691 Controls the processor to be used for enabling errata workarounds for
694 maint check libthread-db
695 Run integrity checks on the current inferior's thread debugging
698 maint set check-libthread-db (on|off)
699 maint show check-libthread-db
700 Control whether to run integrity checks on inferior specific thread
701 debugging libraries as they are loaded. The default is not to
706 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
708 ** The commands attached to a breakpoint can be set by assigning to
709 the breakpoint's "commands" field.
711 ** gdb.execute can now execute multi-line gdb commands.
713 ** The new functions gdb.convenience_variable and
714 gdb.set_convenience_variable can be used to get and set the value
715 of convenience variables.
717 ** A gdb.Parameter will no longer print the "set" help text on an
718 ordinary "set"; instead by default a "set" will be silent unless
719 the get_set_string method returns a non-empty string.
723 RiscV ELF riscv*-*-elf
725 * Removed targets and native configurations
727 m88k running OpenBSD m88*-*-openbsd*
728 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
729 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
730 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
732 * Aarch64/Linux hardware watchpoints improvements
734 Hardware watchpoints on unaligned addresses are now properly
735 supported when running Linux kernel 4.10 or higher: read and access
736 watchpoints are no longer spuriously missed, and all watchpoints
737 lengths between 1 and 8 bytes are supported. On older kernels,
738 watchpoints set on unaligned addresses are no longer missed, with
739 the tradeoff that there is a possibility of false hits being
744 --enable-codesign=CERT
745 This can be used to invoke "codesign -s CERT" after building gdb.
746 This option is useful on macOS, where code signing is required for
747 gdb to work properly.
749 --disable-gdbcli has been removed
750 This is now silently accepted, but does nothing.
752 *** Changes in GDB 8.1
754 * GDB now supports dynamically creating arbitrary register groups specified
755 in XML target descriptions. This allows for finer grain grouping of
756 registers on systems with a large amount of registers.
758 * The 'ptype' command now accepts a '/o' flag, which prints the
759 offsets and sizes of fields in a struct, like the pahole(1) tool.
761 * New "--readnever" command line option instructs GDB to not read each
762 symbol file's symbolic debug information. This makes startup faster
763 but at the expense of not being able to perform symbolic debugging.
764 This option is intended for use cases where symbolic debugging will
765 not be used, e.g., when you only need to dump the debuggee's core.
767 * GDB now uses the GNU MPFR library, if available, to emulate target
768 floating-point arithmetic during expression evaluation when the target
769 uses different floating-point formats than the host. At least version
770 3.1 of GNU MPFR is required.
772 * GDB now supports access to the guarded-storage-control registers and the
773 software-based guarded-storage broadcast control registers on IBM z14.
775 * On Unix systems, GDB now supports transmitting environment variables
776 that are to be set or unset to GDBserver. These variables will
777 affect the environment to be passed to the remote inferior.
779 To inform GDB of environment variables that are to be transmitted to
780 GDBserver, use the "set environment" command. Only user set
781 environment variables are sent to GDBserver.
783 To inform GDB of environment variables that are to be unset before
784 the remote inferior is started by the GDBserver, use the "unset
785 environment" command.
787 * Completion improvements
789 ** GDB can now complete function parameters in linespecs and
790 explicit locations without quoting. When setting breakpoints,
791 quoting around functions names to help with TAB-completion is
792 generally no longer necessary. For example, this now completes
795 (gdb) b function(in[TAB]
796 (gdb) b function(int)
798 Related, GDB is no longer confused with completing functions in
799 C++ anonymous namespaces:
802 (gdb) b (anonymous namespace)::[TAB][TAB]
803 (anonymous namespace)::a_function()
804 (anonymous namespace)::b_function()
806 ** GDB now has much improved linespec and explicit locations TAB
807 completion support, that better understands what you're
808 completing and offers better suggestions. For example, GDB no
809 longer offers data symbols as possible completions when you're
810 setting a breakpoint.
812 ** GDB now TAB-completes label symbol names.
814 ** The "complete" command now mimics TAB completion accurately.
816 * New command line options (gcore)
819 Dump all memory mappings.
821 * Breakpoints on C++ functions are now set on all scopes by default
823 By default, breakpoints on functions/methods are now interpreted as
824 specifying all functions with the given name ignoring missing
825 leading scopes (namespaces and classes).
827 For example, assuming a C++ program with symbols named:
832 both commands "break func()" and "break B::func()" set a breakpoint
835 You can use the new flag "-qualified" to override this. This makes
836 GDB interpret the specified function name as a complete
837 fully-qualified name instead. For example, using the same C++
838 program, the "break -q B::func" command sets a breakpoint on
839 "B::func", only. A parameter has been added to the Python
840 gdb.Breakpoint constructor to achieve the same result when creating
841 a breakpoint from Python.
843 * Breakpoints on functions marked with C++ ABI tags
845 GDB can now set breakpoints on functions marked with C++ ABI tags
846 (e.g., [abi:cxx11]). See here for a description of ABI tags:
847 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
849 Functions with a C++11 abi tag are demangled/displayed like this:
851 function[abi:cxx11](int)
854 You can now set a breakpoint on such functions simply as if they had
857 (gdb) b function(int)
859 Or if you need to disambiguate between tags, like:
861 (gdb) b function[abi:other_tag](int)
863 Tab completion was adjusted accordingly as well.
867 ** New events gdb.new_inferior, gdb.inferior_deleted, and
868 gdb.new_thread are emitted. See the manual for further
869 description of these.
871 ** A new function, "gdb.rbreak" has been added to the Python API.
872 This function allows the setting of a large number of breakpoints
873 via a regex pattern in Python. See the manual for further details.
875 ** Python breakpoints can now accept explicit locations. See the
876 manual for a further description of this feature.
879 * New features in the GDB remote stub, GDBserver
881 ** GDBserver is now able to start inferior processes with a
882 specified initial working directory.
884 The user can set the desired working directory to be used from
885 GDB using the new "set cwd" command.
887 ** New "--selftest" command line option runs some GDBserver self
888 tests. These self tests are disabled in releases.
890 ** On Unix systems, GDBserver now does globbing expansion and variable
891 substitution in inferior command line arguments.
893 This is done by starting inferiors using a shell, like GDB does.
894 See "set startup-with-shell" in the user manual for how to disable
895 this from GDB when using "target extended-remote". When using
896 "target remote", you can disable the startup with shell by using the
897 new "--no-startup-with-shell" GDBserver command line option.
899 ** On Unix systems, GDBserver now supports receiving environment
900 variables that are to be set or unset from GDB. These variables
901 will affect the environment to be passed to the inferior.
903 * When catching an Ada exception raised with a message, GDB now prints
904 the message in the catchpoint hit notification. In GDB/MI mode, that
905 information is provided as an extra field named "exception-message"
906 in the *stopped notification.
908 * Trait objects can now be inspected When debugging Rust code. This
909 requires compiler support which will appear in Rust 1.24.
913 QEnvironmentHexEncoded
914 Inform GDBserver of an environment variable that is to be passed to
915 the inferior when starting it.
918 Inform GDBserver of an environment variable that is to be unset
919 before starting the remote inferior.
922 Inform GDBserver that the environment should be reset (i.e.,
923 user-set environment variables should be unset).
926 Indicates whether the inferior must be started with a shell or not.
929 Tell GDBserver that the inferior to be started should use a specific
932 * The "maintenance print c-tdesc" command now takes an optional
933 argument which is the file name of XML target description.
935 * The "maintenance selftest" command now takes an optional argument to
936 filter the tests to be run.
938 * The "enable", and "disable" commands now accept a range of
939 breakpoint locations, e.g. "enable 1.3-5".
944 Set and show the current working directory for the inferior.
947 Set and show compilation command used for compiling and injecting code
948 with the 'compile' commands.
950 set debug separate-debug-file
951 show debug separate-debug-file
952 Control the display of debug output about separate debug file search.
954 set dump-excluded-mappings
955 show dump-excluded-mappings
956 Control whether mappings marked with the VM_DONTDUMP flag should be
957 dumped when generating a core file.
960 List the registered selftests.
963 Start the debugged program stopping at the first instruction.
966 Control display of debugging messages related to OpenRISC targets.
968 set|show print type nested-type-limit
969 Set and show the limit of nesting level for nested types that the
970 type printer will show.
972 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
975 * Safer/improved support for debugging with no debug info
977 GDB no longer assumes functions with no debug information return
980 This means that GDB now refuses to call such functions unless you
981 tell it the function's type, by either casting the call to the
982 declared return type, or by casting the function to a function
983 pointer of the right type, and calling that:
985 (gdb) p getenv ("PATH")
986 'getenv' has unknown return type; cast the call to its declared return type
987 (gdb) p (char *) getenv ("PATH")
988 $1 = 0x7fffffffe "/usr/local/bin:/"...
989 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
990 $2 = 0x7fffffffe "/usr/local/bin:/"...
992 Similarly, GDB no longer assumes that global variables with no debug
993 info have type 'int', and refuses to print the variable's value
994 unless you tell it the variable's type:
997 'var' has unknown type; cast it to its declared type
1001 * New native configurations
1003 FreeBSD/aarch64 aarch64*-*-freebsd*
1004 FreeBSD/arm arm*-*-freebsd*
1008 FreeBSD/aarch64 aarch64*-*-freebsd*
1009 FreeBSD/arm arm*-*-freebsd*
1010 OpenRISC ELF or1k*-*-elf
1012 * Removed targets and native configurations
1014 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1016 *** Changes in GDB 8.0
1018 * GDB now supports access to the PKU register on GNU/Linux. The register is
1019 added by the Memory Protection Keys for Userspace feature which will be
1020 available in future Intel CPUs.
1022 * GDB now supports C++11 rvalue references.
1026 ** New functions to start, stop and access a running btrace recording.
1027 ** Rvalue references are now supported in gdb.Type.
1029 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1032 * Building GDB and GDBserver now requires a C++11 compiler.
1034 For example, GCC 4.8 or later.
1036 It is no longer possible to build GDB or GDBserver with a C
1037 compiler. The --disable-build-with-cxx configure option has been
1040 * Building GDB and GDBserver now requires GNU make >= 3.81.
1042 It is no longer supported to build GDB or GDBserver with another
1043 implementation of the make program or an earlier version of GNU make.
1045 * Native debugging on MS-Windows supports command-line redirection
1047 Command-line arguments used for starting programs on MS-Windows can
1048 now include redirection symbols supported by native Windows shells,
1049 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1050 as "run", "start", and "set args", as well as the corresponding MI
1053 * Support for thread names on MS-Windows.
1055 GDB now catches and handles the special exception that programs
1056 running on MS-Windows use to assign names to threads in the
1059 * Support for Java programs compiled with gcj has been removed.
1061 * User commands now accept an unlimited number of arguments.
1062 Previously, only up to 10 was accepted.
1064 * The "eval" command now expands user-defined command arguments.
1066 This makes it easier to process a variable number of arguments:
1071 eval "print $arg%d", $i
1076 * Target descriptions can now describe registers for sparc32 and sparc64.
1078 * GDB now supports DWARF version 5 (debug information format).
1079 Its .debug_names index is not yet supported.
1081 * New native configurations
1083 FreeBSD/mips mips*-*-freebsd
1087 Synopsys ARC arc*-*-elf32
1088 FreeBSD/mips mips*-*-freebsd
1090 * Removed targets and native configurations
1092 Alpha running FreeBSD alpha*-*-freebsd*
1093 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1098 Erases all the flash memory regions reported by the target.
1100 maint print arc arc-instruction address
1101 Print internal disassembler information about instruction at a given address.
1105 set disassembler-options
1106 show disassembler-options
1107 Controls the passing of target specific information to the disassembler.
1108 If it is necessary to specify more than one disassembler option then
1109 multiple options can be placed together into a comma separated list.
1110 The default value is the empty string. Currently, the only supported
1111 targets are ARM, PowerPC and S/390.
1116 Erases all the flash memory regions reported by the target. This is
1117 equivalent to the CLI command flash-erase.
1119 -file-list-shared-libraries
1120 List the shared libraries in the program. This is
1121 equivalent to the CLI command "info shared".
1124 Catchpoints stopping the program when Ada exceptions are
1125 handled. This is equivalent to the CLI command "catch handlers".
1127 *** Changes in GDB 7.12
1129 * GDB and GDBserver now build with a C++ compiler by default.
1131 The --enable-build-with-cxx configure option is now enabled by
1132 default. One must now explicitly configure with
1133 --disable-build-with-cxx in order to build with a C compiler. This
1134 option will be removed in a future release.
1136 * GDBserver now supports recording btrace without maintaining an active
1139 * GDB now supports a negative repeat count in the 'x' command to examine
1140 memory backward from the given address. For example:
1143 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1144 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1145 (gdb) x/-5i 0x0000000000400580
1146 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1147 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1148 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1149 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1150 0x40057b <main(int, char**)+25>:
1151 callq 0x400536 <Func1(int, char const*)>
1153 * Fortran: Support structures with fields of dynamic types and
1154 arrays of dynamic types.
1156 * The symbol dumping maintenance commands have new syntax.
1157 maint print symbols [-pc address] [--] [filename]
1158 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1159 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1160 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1161 maint print msymbols [-objfile objfile] [--] [filename]
1163 * GDB now supports multibit bitfields and enums in target register
1166 * New Python-based convenience function $_as_string(val), which returns
1167 the textual representation of a value. This function is especially
1168 useful to obtain the text label of an enum value.
1170 * Intel MPX bound violation handling.
1172 Segmentation faults caused by a Intel MPX boundary violation
1173 now display the kind of violation (upper or lower), the memory
1174 address accessed and the memory bounds, along with the usual
1175 signal received and code location.
1179 Program received signal SIGSEGV, Segmentation fault
1180 Upper bound violation while accessing address 0x7fffffffc3b3
1181 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1182 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1184 * Rust language support.
1185 GDB now supports debugging programs written in the Rust programming
1186 language. See https://www.rust-lang.org/ for more information about
1189 * Support for running interpreters on specified input/output devices
1191 GDB now supports a new mechanism that allows frontends to provide
1192 fully featured GDB console views, as a better alternative to
1193 building such views on top of the "-interpreter-exec console"
1194 command. See the new "new-ui" command below. With that command,
1195 frontends can now start GDB in the traditional command-line mode
1196 running in an embedded terminal emulator widget, and create a
1197 separate MI interpreter running on a specified i/o device. In this
1198 way, GDB handles line editing, history, tab completion, etc. in the
1199 console all by itself, and the GUI uses the separate MI interpreter
1200 for its own control and synchronization, invisible to the command
1203 * The "catch syscall" command catches groups of related syscalls.
1205 The "catch syscall" command now supports catching a group of related
1206 syscalls using the 'group:' or 'g:' prefix.
1211 skip -gfile file-glob-pattern
1212 skip -function function
1213 skip -rfunction regular-expression
1214 A generalized form of the skip command, with new support for
1215 glob-style file names and regular expressions for function names.
1216 Additionally, a file spec and a function spec may now be combined.
1218 maint info line-table REGEXP
1219 Display the contents of GDB's internal line table data struture.
1222 Run any GDB unit tests that were compiled in.
1225 Start a new user interface instance running INTERP as interpreter,
1226 using the TTY file for input/output.
1230 ** gdb.Breakpoint objects have a new attribute "pending", which
1231 indicates whether the breakpoint is pending.
1232 ** Three new breakpoint-related events have been added:
1233 gdb.breakpoint_created, gdb.breakpoint_modified, and
1234 gdb.breakpoint_deleted.
1236 signal-event EVENTID
1237 Signal ("set") the given MS-Windows event object. This is used in
1238 conjunction with the Windows JIT debugging (AeDebug) support, where
1239 the OS suspends a crashing process until a debugger can attach to
1240 it. Resuming the crashing process, in order to debug it, is done by
1241 signalling an event.
1243 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1244 was added in GDBserver, including JIT compiling fast tracepoint's
1245 conditional expression bytecode into native code.
1247 * Support for various remote target protocols and ROM monitors has
1250 target m32rsdi Remote M32R debugging over SDI
1251 target mips MIPS remote debugging protocol
1252 target pmon PMON ROM monitor
1253 target ddb NEC's DDB variant of PMON for Vr4300
1254 target rockhopper NEC RockHopper variant of PMON
1255 target lsi LSI variant of PMO
1257 * Support for tracepoints and fast tracepoints on powerpc-linux,
1258 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1259 including JIT compiling fast tracepoint's conditional expression
1260 bytecode into native code.
1262 * MI async record =record-started now includes the method and format used for
1263 recording. For example:
1265 =record-started,thread-group="i1",method="btrace",format="bts"
1267 * MI async record =thread-selected now includes the frame field. For example:
1269 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1273 Andes NDS32 nds32*-*-elf
1275 *** Changes in GDB 7.11
1277 * GDB now supports debugging kernel-based threads on FreeBSD.
1279 * Per-inferior thread numbers
1281 Thread numbers are now per inferior instead of global. If you're
1282 debugging multiple inferiors, GDB displays thread IDs using a
1283 qualified INF_NUM.THR_NUM form. For example:
1287 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1288 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1289 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1290 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1292 As consequence, thread numbers as visible in the $_thread
1293 convenience variable and in Python's InferiorThread.num attribute
1294 are no longer unique between inferiors.
1296 GDB now maintains a second thread ID per thread, referred to as the
1297 global thread ID, which is the new equivalent of thread numbers in
1298 previous releases. See also $_gthread below.
1300 For backwards compatibility, MI's thread IDs always refer to global
1303 * Commands that accept thread IDs now accept the qualified
1304 INF_NUM.THR_NUM form as well. For example:
1307 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1310 * In commands that accept a list of thread IDs, you can now refer to
1311 all threads of an inferior using a star wildcard. GDB accepts
1312 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1313 refer to all threads of the current inferior. For example, "info
1316 * You can use "info threads -gid" to display the global thread ID of
1319 * The new convenience variable $_gthread holds the global number of
1322 * The new convenience variable $_inferior holds the number of the
1325 * GDB now displays the ID and name of the thread that hit a breakpoint
1326 or received a signal, if your program is multi-threaded. For
1329 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1330 Thread 1 "main" received signal SIGINT, Interrupt.
1332 * Record btrace now supports non-stop mode.
1334 * Support for tracepoints on aarch64-linux was added in GDBserver.
1336 * The 'record instruction-history' command now indicates speculative execution
1337 when using the Intel Processor Trace recording format.
1339 * GDB now allows users to specify explicit locations, bypassing
1340 the linespec parser. This feature is also available to GDB/MI
1343 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1344 GDB now is able to debug both AArch64 applications and ARM applications
1347 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1348 including JIT compiling fast tracepoint's conditional expression bytecode
1351 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1353 * "info threads", "info inferiors", "info display", "info checkpoints"
1354 and "maint info program-spaces" now list the corresponding items in
1355 ascending ID order, for consistency with all other "info" commands.
1357 * In Ada, the overloads selection menu has been enhanced to display the
1358 parameter types and the return types for the matching overloaded subprograms.
1362 maint set target-non-stop (on|off|auto)
1363 maint show target-non-stop
1364 Control whether GDB targets always operate in non-stop mode even if
1365 "set non-stop" is "off". The default is "auto", meaning non-stop
1366 mode is enabled if supported by the target.
1368 maint set bfd-sharing
1369 maint show bfd-sharing
1370 Control the reuse of bfd objects.
1373 show debug bfd-cache
1374 Control display of debugging info regarding bfd caching.
1378 Control display of debugging info regarding FreeBSD threads.
1380 set remote multiprocess-extensions-packet
1381 show remote multiprocess-extensions-packet
1382 Set/show the use of the remote protocol multiprocess extensions.
1384 set remote thread-events
1385 show remote thread-events
1386 Set/show the use of thread create/exit events.
1388 set ada print-signatures on|off
1389 show ada print-signatures"
1390 Control whether parameter types and return types are displayed in overloads
1391 selection menus. It is activaled (@code{on}) by default.
1395 Controls the maximum size of memory, in bytes, that GDB will
1396 allocate for value contents. Prevents incorrect programs from
1397 causing GDB to allocate overly large buffers. Default is 64k.
1399 * The "disassemble" command accepts a new modifier: /s.
1400 It prints mixed source+disassembly like /m with two differences:
1401 - disassembled instructions are now printed in program order, and
1402 - and source for all relevant files is now printed.
1403 The "/m" option is now considered deprecated: its "source-centric"
1404 output hasn't proved useful in practice.
1406 * The "record instruction-history" command accepts a new modifier: /s.
1407 It behaves exactly like /m and prints mixed source+disassembly.
1409 * The "set scheduler-locking" command supports a new mode "replay".
1410 It behaves like "off" in record mode and like "on" in replay mode.
1412 * Support for various ROM monitors has been removed:
1414 target dbug dBUG ROM monitor for Motorola ColdFire
1415 target picobug Motorola picobug monitor
1416 target dink32 DINK32 ROM monitor for PowerPC
1417 target m32r Renesas M32R/D ROM monitor
1418 target mon2000 mon2000 ROM monitor
1419 target ppcbug PPCBUG ROM monitor for PowerPC
1421 * Support for reading/writing memory and extracting values on architectures
1422 whose memory is addressable in units of any integral multiple of 8 bits.
1425 Allows to break when an Ada exception is handled.
1427 * New remote packets
1430 Indicates that an exec system call was executed.
1432 exec-events feature in qSupported
1433 The qSupported packet allows GDB to request support for exec
1434 events using the new 'gdbfeature' exec-event, and the qSupported
1435 response can contain the corresponding 'stubfeature'. Set and
1436 show commands can be used to display whether these features are enabled.
1439 Equivalent to interrupting with the ^C character, but works in
1442 thread created stop reason (T05 create:...)
1443 Indicates that the thread was just created and is stopped at entry.
1445 thread exit stop reply (w exitcode;tid)
1446 Indicates that the thread has terminated.
1449 Enables/disables thread create and exit event reporting. For
1450 example, this is used in non-stop mode when GDB stops a set of
1451 threads and synchronously waits for the their corresponding stop
1452 replies. Without exit events, if one of the threads exits, GDB
1453 would hang forever not knowing that it should no longer expect a
1454 stop for that same thread.
1457 Indicates that there are no resumed threads left in the target (all
1458 threads are stopped). The remote stub reports support for this stop
1459 reply to GDB's qSupported query.
1462 Enables/disables catching syscalls from the inferior process.
1463 The remote stub reports support for this packet to GDB's qSupported query.
1465 syscall_entry stop reason
1466 Indicates that a syscall was just called.
1468 syscall_return stop reason
1469 Indicates that a syscall just returned.
1471 * Extended-remote exec events
1473 ** GDB now has support for exec events on extended-remote Linux targets.
1474 For such targets with Linux kernels 2.5.46 and later, this enables
1475 follow-exec-mode and exec catchpoints.
1477 set remote exec-event-feature-packet
1478 show remote exec-event-feature-packet
1479 Set/show the use of the remote exec event feature.
1481 * Thread names in remote protocol
1483 The reply to qXfer:threads:read may now include a name attribute for each
1486 * Target remote mode fork and exec events
1488 ** GDB now has support for fork and exec events on target remote mode
1489 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1490 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1491 fork and exec catchpoints.
1493 * Remote syscall events
1495 ** GDB now has support for catch syscall on remote Linux targets,
1496 currently enabled on x86/x86_64 architectures.
1498 set remote catch-syscall-packet
1499 show remote catch-syscall-packet
1500 Set/show the use of the remote catch syscall feature.
1504 ** The -var-set-format command now accepts the zero-hexadecimal
1505 format. It outputs data in hexadecimal format with zero-padding on the
1510 ** gdb.InferiorThread objects have a new attribute "global_num",
1511 which refers to the thread's global thread ID. The existing
1512 "num" attribute now refers to the thread's per-inferior number.
1513 See "Per-inferior thread numbers" above.
1514 ** gdb.InferiorThread objects have a new attribute "inferior", which
1515 is the Inferior object the thread belongs to.
1517 *** Changes in GDB 7.10
1519 * Support for process record-replay and reverse debugging on aarch64*-linux*
1520 targets has been added. GDB now supports recording of A64 instruction set
1521 including advance SIMD instructions.
1523 * Support for Sun's version of the "stabs" debug file format has been removed.
1525 * GDB now honors the content of the file /proc/PID/coredump_filter
1526 (PID is the process ID) on GNU/Linux systems. This file can be used
1527 to specify the types of memory mappings that will be included in a
1528 corefile. For more information, please refer to the manual page of
1529 "core(5)". GDB also has a new command: "set use-coredump-filter
1530 on|off". It allows to set whether GDB will read the content of the
1531 /proc/PID/coredump_filter file when generating a corefile.
1533 * The "info os" command on GNU/Linux can now display information on
1535 "info os cpus" Listing of all cpus/cores on the system
1537 * GDB has two new commands: "set serial parity odd|even|none" and
1538 "show serial parity". These allows to set or show parity for the
1541 * The "info source" command now displays the producer string if it was
1542 present in the debug info. This typically includes the compiler version
1543 and may include things like its command line arguments.
1545 * The "info dll", an alias of the "info sharedlibrary" command,
1546 is now available on all platforms.
1548 * Directory names supplied to the "set sysroot" commands may be
1549 prefixed with "target:" to tell GDB to access shared libraries from
1550 the target system, be it local or remote. This replaces the prefix
1551 "remote:". The default sysroot has been changed from "" to
1552 "target:". "remote:" is automatically converted to "target:" for
1553 backward compatibility.
1555 * The system root specified by "set sysroot" will be prepended to the
1556 filename of the main executable (if reported to GDB as absolute by
1557 the operating system) when starting processes remotely, and when
1558 attaching to already-running local or remote processes.
1560 * GDB now supports automatic location and retrieval of executable
1561 files from remote targets. Remote debugging can now be initiated
1562 using only a "target remote" or "target extended-remote" command
1563 (no "set sysroot" or "file" commands are required). See "New remote
1566 * The "dump" command now supports verilog hex format.
1568 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1570 * On GNU/Linux, GDB and gdbserver are now able to access executable
1571 and shared library files without a "set sysroot" command when
1572 attaching to processes running in different mount namespaces from
1573 the debugger. This makes it possible to attach to processes in
1574 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1575 See "New remote packets" below.
1577 * The "tui reg" command now provides completion for all of the
1578 available register groups, including target specific groups.
1580 * The HISTSIZE environment variable is no longer read when determining
1581 the size of GDB's command history. GDB now instead reads the dedicated
1582 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1583 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1588 ** Memory ports can now be unbuffered.
1592 ** gdb.Objfile objects have a new attribute "username",
1593 which is the name of the objfile as specified by the user,
1594 without, for example, resolving symlinks.
1595 ** You can now write frame unwinders in Python.
1596 ** gdb.Type objects have a new method "optimized_out",
1597 returning optimized out gdb.Value instance of this type.
1598 ** gdb.Value objects have new methods "reference_value" and
1599 "const_value" which return a reference to the value and a
1600 "const" version of the value respectively.
1604 maint print symbol-cache
1605 Print the contents of the symbol cache.
1607 maint print symbol-cache-statistics
1608 Print statistics of symbol cache usage.
1610 maint flush-symbol-cache
1611 Flush the contents of the symbol cache.
1615 Start branch trace recording using Branch Trace Store (BTS) format.
1618 Evaluate expression by using the compiler and print result.
1622 Explicit commands for enabling and disabling tui mode.
1625 set mpx bound on i386 and amd64
1626 Support for bound table investigation on Intel MPX enabled applications.
1630 Start branch trace recording using Intel Processor Trace format.
1633 Print information about branch tracing internals.
1635 maint btrace packet-history
1636 Print the raw branch tracing data.
1638 maint btrace clear-packet-history
1639 Discard the stored raw branch tracing data.
1642 Discard all branch tracing data. It will be fetched and processed
1643 anew by the next "record" command.
1648 Renamed from "set debug dwarf2-die".
1649 show debug dwarf-die
1650 Renamed from "show debug dwarf2-die".
1652 set debug dwarf-read
1653 Renamed from "set debug dwarf2-read".
1654 show debug dwarf-read
1655 Renamed from "show debug dwarf2-read".
1657 maint set dwarf always-disassemble
1658 Renamed from "maint set dwarf2 always-disassemble".
1659 maint show dwarf always-disassemble
1660 Renamed from "maint show dwarf2 always-disassemble".
1662 maint set dwarf max-cache-age
1663 Renamed from "maint set dwarf2 max-cache-age".
1664 maint show dwarf max-cache-age
1665 Renamed from "maint show dwarf2 max-cache-age".
1667 set debug dwarf-line
1668 show debug dwarf-line
1669 Control display of debugging info regarding DWARF line processing.
1672 show max-completions
1673 Set the maximum number of candidates to be considered during
1674 completion. The default value is 200. This limit allows GDB
1675 to avoid generating large completion lists, the computation of
1676 which can cause the debugger to become temporarily unresponsive.
1678 set history remove-duplicates
1679 show history remove-duplicates
1680 Control the removal of duplicate history entries.
1682 maint set symbol-cache-size
1683 maint show symbol-cache-size
1684 Control the size of the symbol cache.
1686 set|show record btrace bts buffer-size
1687 Set and show the size of the ring buffer used for branch tracing in
1689 The obtained size may differ from the requested size. Use "info
1690 record" to see the obtained buffer size.
1692 set debug linux-namespaces
1693 show debug linux-namespaces
1694 Control display of debugging info regarding Linux namespaces.
1696 set|show record btrace pt buffer-size
1697 Set and show the size of the ring buffer used for branch tracing in
1698 Intel Processor Trace format.
1699 The obtained size may differ from the requested size. Use "info
1700 record" to see the obtained buffer size.
1702 maint set|show btrace pt skip-pad
1703 Set and show whether PAD packets are skipped when computing the
1706 * The command 'thread apply all' can now support new option '-ascending'
1707 to call its specified command for all threads in ascending order.
1709 * Python/Guile scripting
1711 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1712 special section named `.debug_gdb_scripts'.
1714 * New remote packets
1716 qXfer:btrace-conf:read
1717 Return the branch trace configuration for the current thread.
1719 Qbtrace-conf:bts:size
1720 Set the requested ring buffer size for branch tracing in BTS format.
1723 Enable Intel Procesor Trace-based branch tracing for the current
1724 process. The remote stub reports support for this packet to GDB's
1727 Qbtrace-conf:pt:size
1728 Set the requested ring buffer size for branch tracing in Intel Processor
1732 Indicates a memory breakpoint instruction was executed, irrespective
1733 of whether it was GDB that planted the breakpoint or the breakpoint
1734 is hardcoded in the program. This is required for correct non-stop
1738 Indicates the target stopped for a hardware breakpoint. This is
1739 required for correct non-stop mode operation.
1742 Return information about files on the remote system.
1744 qXfer:exec-file:read
1745 Return the full absolute name of the file that was executed to
1746 create a process running on the remote system.
1749 Select the filesystem on which vFile: operations with filename
1750 arguments will operate. This is required for GDB to be able to
1751 access files on remote targets where the remote stub does not
1752 share a common filesystem with the inferior(s).
1755 Indicates that a fork system call was executed.
1758 Indicates that a vfork system call was executed.
1760 vforkdone stop reason
1761 Indicates that a vfork child of the specified process has executed
1762 an exec or exit, allowing the vfork parent to resume execution.
1764 fork-events and vfork-events features in qSupported
1765 The qSupported packet allows GDB to request support for fork and
1766 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1767 and the qSupported response can contain the corresponding
1768 'stubfeatures'. Set and show commands can be used to display
1769 whether these features are enabled.
1771 * Extended-remote fork events
1773 ** GDB now has support for fork events on extended-remote Linux
1774 targets. For targets with Linux kernels 2.5.60 and later, this
1775 enables follow-fork-mode and detach-on-fork for both fork and
1776 vfork, as well as fork and vfork catchpoints.
1778 * The info record command now shows the recording format and the
1779 branch tracing configuration for the current thread when using
1780 the btrace record target.
1781 For the BTS format, it shows the ring buffer size.
1783 * GDB now has support for DTrace USDT (Userland Static Defined
1784 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1786 * GDB now supports access to vector registers on S/390 GNU/Linux
1789 * Removed command line options
1791 -xdb HP-UX XDB compatibility mode.
1793 * Removed targets and native configurations
1795 HP/PA running HP-UX hppa*-*-hpux*
1796 Itanium running HP-UX ia64-*-hpux*
1798 * New configure options
1801 This configure option allows the user to build GDB with support for
1802 Intel Processor Trace (default: auto). This requires libipt.
1804 --with-libipt-prefix=PATH
1805 Specify the path to the version of libipt that GDB should use.
1806 $PATH/include should contain the intel-pt.h header and
1807 $PATH/lib should contain the libipt.so library.
1809 *** Changes in GDB 7.9.1
1813 ** Xmethods can now specify a result type.
1815 *** Changes in GDB 7.9
1817 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1821 ** You can now access frame registers from Python scripts.
1822 ** New attribute 'producer' for gdb.Symtab objects.
1823 ** gdb.Objfile objects have a new attribute "progspace",
1824 which is the gdb.Progspace object of the containing program space.
1825 ** gdb.Objfile objects have a new attribute "owner".
1826 ** gdb.Objfile objects have a new attribute "build_id",
1827 which is the build ID generated when the file was built.
1828 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1829 ** A new event "gdb.clear_objfiles" has been added, triggered when
1830 selecting a new file to debug.
1831 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1832 ** New function gdb.lookup_objfile.
1834 New events which are triggered when GDB modifies the state of the
1837 ** gdb.events.inferior_call_pre: Function call is about to be made.
1838 ** gdb.events.inferior_call_post: Function call has just been made.
1839 ** gdb.events.memory_changed: A memory location has been altered.
1840 ** gdb.events.register_changed: A register has been altered.
1842 * New Python-based convenience functions:
1844 ** $_caller_is(name [, number_of_frames])
1845 ** $_caller_matches(regexp [, number_of_frames])
1846 ** $_any_caller_is(name [, number_of_frames])
1847 ** $_any_caller_matches(regexp [, number_of_frames])
1849 * GDB now supports the compilation and injection of source code into
1850 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1851 to compile the source code to object code, and if successful, inject
1852 and execute that code within the current context of the inferior.
1853 Currently the C language is supported. The commands used to
1854 interface with this new feature are:
1856 compile code [-raw|-r] [--] [source code]
1857 compile file [-raw|-r] filename
1861 demangle [-l language] [--] name
1862 Demangle "name" in the specified language, or the current language
1863 if elided. This command is renamed from the "maint demangle" command.
1864 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1865 as "maint demangler-warning".
1867 queue-signal signal-name-or-number
1868 Queue a signal to be delivered to the thread when it is resumed.
1870 add-auto-load-scripts-directory directory
1871 Add entries to the list of directories from which to load auto-loaded
1874 maint print user-registers
1875 List all currently available "user" registers.
1877 compile code [-r|-raw] [--] [source code]
1878 Compile, inject, and execute in the inferior the executable object
1879 code produced by compiling the provided source code.
1881 compile file [-r|-raw] filename
1882 Compile and inject into the inferior the executable object code
1883 produced by compiling the source code stored in the filename
1886 * On resume, GDB now always passes the signal the program had stopped
1887 for to the thread the signal was sent to, even if the user changed
1888 threads before resuming. Previously GDB would often (but not
1889 always) deliver the signal to the thread that happens to be current
1892 * Conversely, the "signal" command now consistently delivers the
1893 requested signal to the current thread. GDB now asks for
1894 confirmation if the program had stopped for a signal and the user
1895 switched threads meanwhile.
1897 * "breakpoint always-inserted" modes "off" and "auto" merged.
1899 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1900 won't remove breakpoints from the target until all threads stop,
1901 even in non-stop mode. The "auto" mode has been removed, and "off"
1902 is now the default mode.
1906 set debug symbol-lookup
1907 show debug symbol-lookup
1908 Control display of debugging info regarding symbol lookup.
1912 ** The -list-thread-groups command outputs an exit-code field for
1913 inferiors that have exited.
1917 MIPS SDE mips*-sde*-elf*
1921 Support for these obsolete configurations has been removed.
1923 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1924 SGI Irix-5.x mips-*-irix5*
1925 SGI Irix-6.x mips-*-irix6*
1926 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1927 VAX running Ultrix vax-*-ultrix*
1929 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1930 and "assf"), have been removed. Use the "sharedlibrary" command, or
1931 its alias "share", instead.
1933 *** Changes in GDB 7.8
1935 * New command line options
1938 This is an alias for the --data-directory option.
1940 * GDB supports printing and modifying of variable length automatic arrays
1941 as specified in ISO C99.
1943 * The ARM simulator now supports instruction level tracing
1944 with or without disassembly.
1948 GDB now has support for scripting using Guile. Whether this is
1949 available is determined at configure time.
1950 Guile version 2.0 or greater is required.
1951 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1953 * New commands (for set/show, see "New options" below)
1957 Invoke CODE by passing it to the Guile interpreter.
1961 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1963 info auto-load guile-scripts [regexp]
1964 Print the list of automatically loaded Guile scripts.
1966 * The source command is now capable of sourcing Guile scripts.
1967 This feature is dependent on the debugger being built with Guile support.
1971 set print symbol-loading (off|brief|full)
1972 show print symbol-loading
1973 Control whether to print informational messages when loading symbol
1974 information for a file. The default is "full", but when debugging
1975 programs with large numbers of shared libraries the amount of output
1976 becomes less useful.
1978 set guile print-stack (none|message|full)
1979 show guile print-stack
1980 Show a stack trace when an error is encountered in a Guile script.
1982 set auto-load guile-scripts (on|off)
1983 show auto-load guile-scripts
1984 Control auto-loading of Guile script files.
1986 maint ada set ignore-descriptive-types (on|off)
1987 maint ada show ignore-descriptive-types
1988 Control whether the debugger should ignore descriptive types in Ada
1989 programs. The default is not to ignore the descriptive types. See
1990 the user manual for more details on descriptive types and the intended
1991 usage of this option.
1993 set auto-connect-native-target
1995 Control whether GDB is allowed to automatically connect to the
1996 native target for the run, attach, etc. commands when not connected
1997 to any target yet. See also "target native" below.
1999 set record btrace replay-memory-access (read-only|read-write)
2000 show record btrace replay-memory-access
2001 Control what memory accesses are allowed during replay.
2003 maint set target-async (on|off)
2004 maint show target-async
2005 This controls whether GDB targets operate in synchronous or
2006 asynchronous mode. Normally the default is asynchronous, if it is
2007 available; but this can be changed to more easily debug problems
2008 occurring only in synchronous mode.
2010 set mi-async (on|off)
2012 Control whether MI asynchronous mode is preferred. This supersedes
2013 "set target-async" of previous GDB versions.
2015 * "set target-async" is deprecated as a CLI option and is now an alias
2016 for "set mi-async" (only puts MI into async mode).
2018 * Background execution commands (e.g., "c&", "s&", etc.) are now
2019 possible ``out of the box'' if the target supports them. Previously
2020 the user would need to explicitly enable the possibility with the
2021 "set target-async on" command.
2023 * New features in the GDB remote stub, GDBserver
2025 ** New option --debug-format=option1[,option2,...] allows one to add
2026 additional text to each output. At present only timestamps
2027 are supported: --debug-format=timestamps.
2028 Timestamps can also be turned on with the
2029 "monitor set debug-format timestamps" command from GDB.
2031 * The 'record instruction-history' command now starts counting instructions
2032 at one. This also affects the instruction ranges reported by the
2033 'record function-call-history' command when given the /i modifier.
2035 * The command 'record function-call-history' supports a new modifier '/c' to
2036 indent the function names based on their call stack depth.
2037 The fields for the '/i' and '/l' modifier have been reordered.
2038 The source line range is now prefixed with 'at'.
2039 The instruction range is now prefixed with 'inst'.
2040 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2041 "record instruction-history" and "list" commands.
2043 * The ranges given as arguments to the 'record function-call-history' and
2044 'record instruction-history' commands are now inclusive.
2046 * The btrace record target now supports the 'record goto' command.
2047 For locations inside the execution trace, the back trace is computed
2048 based on the information stored in the execution trace.
2050 * The btrace record target supports limited reverse execution and replay.
2051 The target does not record data and therefore does not allow reading
2052 memory or registers.
2054 * The "catch syscall" command now works on s390*-linux* targets.
2056 * The "compare-sections" command is no longer specific to target
2057 remote. It now works with all targets.
2059 * All native targets are now consistently called "native".
2060 Consequently, the "target child", "target GNU", "target djgpp",
2061 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2062 commands have been replaced with "target native". The QNX/NTO port
2063 leaves the "procfs" target in place and adds a "native" target for
2064 consistency with other ports. The impact on users should be minimal
2065 as these commands previously either throwed an error, or were
2066 no-ops. The target's name is visible in the output of the following
2067 commands: "help target", "info target", "info files", "maint print
2070 * The "target native" command now connects to the native target. This
2071 can be used to launch native programs even when "set
2072 auto-connect-native-target" is set to off.
2074 * GDB now supports access to Intel MPX registers on GNU/Linux.
2076 * Support for Intel AVX-512 registers on GNU/Linux.
2077 Support displaying and modifying Intel AVX-512 registers
2078 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2080 * New remote packets
2082 qXfer:btrace:read's annex
2083 The qXfer:btrace:read packet supports a new annex 'delta' to read
2084 branch trace incrementally.
2088 ** Valid Python operations on gdb.Value objects representing
2089 structs/classes invoke the corresponding overloaded operators if
2091 ** New `Xmethods' feature in the Python API. Xmethods are
2092 additional methods or replacements for existing methods of a C++
2093 class. This feature is useful for those cases where a method
2094 defined in C++ source code could be inlined or optimized out by
2095 the compiler, making it unavailable to GDB.
2098 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2100 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2101 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2102 its alias "share", instead.
2104 * The commands "set remotebaud" and "show remotebaud" are no longer
2105 supported. Use "set serial baud" and "show serial baud" (respectively)
2110 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2111 target-async". The latter is left as a deprecated alias of the
2112 former for backward compatibility. If the target supports it,
2113 CLI background execution commands are now always possible by
2114 default, independently of whether the frontend stated a
2115 preference for asynchronous execution with "-gdb-set mi-async".
2116 Previously "-gdb-set target-async off" affected both MI execution
2117 commands and CLI execution commands.
2119 *** Changes in GDB 7.7
2121 * Improved support for process record-replay and reverse debugging on
2122 arm*-linux* targets. Support for thumb32 and syscall instruction
2123 recording has been added.
2125 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2127 * GDB now supports Fission DWP file format version 2.
2128 http://gcc.gnu.org/wiki/DebugFission
2130 * New convenience function "$_isvoid", to check whether an expression
2131 is void. A void expression is an expression where the type of the
2132 result is "void". For example, some convenience variables may be
2133 "void" when evaluated (e.g., "$_exitcode" before the execution of
2134 the program being debugged; or an undefined convenience variable).
2135 Another example, when calling a function whose return type is
2138 * The "maintenance print objfiles" command now takes an optional regexp.
2140 * The "catch syscall" command now works on arm*-linux* targets.
2142 * GDB now consistently shows "<not saved>" when printing values of
2143 registers the debug info indicates have not been saved in the frame
2144 and there's nowhere to retrieve them from
2145 (callee-saved/call-clobbered registers):
2150 (gdb) info registers rax
2153 Before, the former would print "<optimized out>", and the latter
2154 "*value not available*".
2156 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2161 ** Frame filters and frame decorators have been added.
2162 ** Temporary breakpoints are now supported.
2163 ** Line tables representation has been added.
2164 ** New attribute 'parent_type' for gdb.Field objects.
2165 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2166 ** New attribute 'name' for gdb.Type objects.
2170 Nios II ELF nios2*-*-elf
2171 Nios II GNU/Linux nios2*-*-linux
2172 Texas Instruments MSP430 msp430*-*-elf
2174 * Removed native configurations
2176 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2177 been removed. ELF variants of these configurations are kept supported.
2179 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2180 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2181 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2182 i[34567]86-*-openbsd3.[0-3]
2183 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2184 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2185 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2189 Like "catch throw", but catches a re-thrown exception.
2190 maint check-psymtabs
2191 Renamed from old "maint check-symtabs".
2193 Perform consistency checks on symtabs.
2194 maint expand-symtabs
2195 Expand symtabs matching an optional regexp.
2198 Display the details of GDB configure-time options.
2200 maint set|show per-command
2201 maint set|show per-command space
2202 maint set|show per-command time
2203 maint set|show per-command symtab
2204 Enable display of per-command gdb resource usage.
2206 remove-symbol-file FILENAME
2207 remove-symbol-file -a ADDRESS
2208 Remove a symbol file added via add-symbol-file. The file to remove
2209 can be identified by its filename or by an address that lies within
2210 the boundaries of this symbol file in memory.
2213 info exceptions REGEXP
2214 Display the list of Ada exceptions defined in the program being
2215 debugged. If provided, only the exceptions whose names match REGEXP
2220 set debug symfile off|on
2222 Control display of debugging info regarding reading symbol files and
2223 symbol tables within those files
2225 set print raw frame-arguments
2226 show print raw frame-arguments
2227 Set/show whether to print frame arguments in raw mode,
2228 disregarding any defined pretty-printers.
2230 set remote trace-status-packet
2231 show remote trace-status-packet
2232 Set/show the use of remote protocol qTStatus packet.
2236 Control display of debugging messages related to Nios II targets.
2240 Control whether target-assisted range stepping is enabled.
2242 set startup-with-shell
2243 show startup-with-shell
2244 Specifies whether Unix child processes are started via a shell or
2249 Use the target memory cache for accesses to the code segment. This
2250 improves performance of remote debugging (particularly disassembly).
2252 * You can now use a literal value 'unlimited' for options that
2253 interpret 0 or -1 as meaning "unlimited". E.g., "set
2254 trace-buffer-size unlimited" is now an alias for "set
2255 trace-buffer-size -1" and "set height unlimited" is now an alias for
2258 * The "set debug symtab-create" debugging option of GDB has been changed to
2259 accept a verbosity level. 0 means "off", 1 provides basic debugging
2260 output, and values of 2 or greater provides more verbose output.
2262 * New command-line options
2264 Display the details of GDB configure-time options.
2266 * The command 'tsave' can now support new option '-ctf' to save trace
2267 buffer in Common Trace Format.
2269 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2272 * GDB now implements the the C++ 'typeid' operator.
2274 * The new convenience variable $_exception holds the exception being
2275 thrown or caught at an exception-related catchpoint.
2277 * The exception-related catchpoints, like "catch throw", now accept a
2278 regular expression which can be used to filter exceptions by type.
2280 * The new convenience variable $_exitsignal is automatically set to
2281 the terminating signal number when the program being debugged dies
2282 due to an uncaught signal.
2286 ** All MI commands now accept an optional "--language" option.
2287 Support for this feature can be verified by using the "-list-features"
2288 command, which should contain "language-option".
2290 ** The new command -info-gdb-mi-command allows the user to determine
2291 whether a GDB/MI command is supported or not.
2293 ** The "^error" result record returned when trying to execute an undefined
2294 GDB/MI command now provides a variable named "code" whose content is the
2295 "undefined-command" error code. Support for this feature can be verified
2296 by using the "-list-features" command, which should contain
2297 "undefined-command-error-code".
2299 ** The -trace-save MI command can optionally save trace buffer in Common
2302 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2304 ** The command -data-list-register-values now accepts an optional
2305 "--skip-unavailable" option. When used, only the available registers
2308 ** The new command -trace-frame-collected dumps collected variables,
2309 computed expressions, tvars, memory and registers in a traceframe.
2311 ** The commands -stack-list-locals, -stack-list-arguments and
2312 -stack-list-variables now accept an option "--skip-unavailable".
2313 When used, only the available locals or arguments are displayed.
2315 ** The -exec-run command now accepts an optional "--start" option.
2316 When used, the command follows the same semantics as the "start"
2317 command, stopping the program's execution at the start of its
2318 main subprogram. Support for this feature can be verified using
2319 the "-list-features" command, which should contain
2320 "exec-run-start-option".
2322 ** The new commands -catch-assert and -catch-exceptions insert
2323 catchpoints stopping the program when Ada exceptions are raised.
2325 ** The new command -info-ada-exceptions provides the equivalent of
2326 the new "info exceptions" command.
2328 * New system-wide configuration scripts
2329 A GDB installation now provides scripts suitable for use as system-wide
2330 configuration scripts for the following systems:
2334 * GDB now supports target-assigned range stepping with remote targets.
2335 This improves the performance of stepping source lines by reducing
2336 the number of control packets from/to GDB. See "New remote packets"
2339 * GDB now understands the element 'tvar' in the XML traceframe info.
2340 It has the id of the collected trace state variables.
2342 * On S/390 targets that provide the transactional-execution feature,
2343 the program interruption transaction diagnostic block (TDB) is now
2344 represented as a number of additional "registers" in GDB.
2346 * New remote packets
2350 The vCont packet supports a new 'r' action, that tells the remote
2351 stub to step through an address range itself, without GDB
2352 involvemement at each single-step.
2354 qXfer:libraries-svr4:read's annex
2355 The previously unused annex of the qXfer:libraries-svr4:read packet
2356 is now used to support passing an argument list. The remote stub
2357 reports support for this argument list to GDB's qSupported query.
2358 The defined arguments are "start" and "prev", used to reduce work
2359 necessary for library list updating, resulting in significant
2362 * New features in the GDB remote stub, GDBserver
2364 ** GDBserver now supports target-assisted range stepping. Currently
2365 enabled on x86/x86_64 GNU/Linux targets.
2367 ** GDBserver now adds element 'tvar' in the XML in the reply to
2368 'qXfer:traceframe-info:read'. It has the id of the collected
2369 trace state variables.
2371 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2374 * New 'z' formatter for printing and examining memory, this displays the
2375 value as hexadecimal zero padded on the left to the size of the type.
2377 * GDB can now use Windows x64 unwinding data.
2379 * The "set remotebaud" command has been replaced by "set serial baud".
2380 Similarly, "show remotebaud" has been replaced by "show serial baud".
2381 The "set remotebaud" and "show remotebaud" commands are still available
2382 to provide backward compatibility with older versions of GDB.
2384 *** Changes in GDB 7.6
2386 * Target record has been renamed to record-full.
2387 Record/replay is now enabled with the "record full" command.
2388 This also affects settings that are associated with full record/replay
2389 that have been moved from "set/show record" to "set/show record full":
2391 set|show record full insn-number-max
2392 set|show record full stop-at-limit
2393 set|show record full memory-query
2395 * A new record target "record-btrace" has been added. The new target
2396 uses hardware support to record the control-flow of a process. It
2397 does not support replaying the execution, but it implements the
2398 below new commands for investigating the recorded execution log.
2399 This new recording method can be enabled using:
2403 The "record-btrace" target is only available on Intel Atom processors
2404 and requires a Linux kernel 2.6.32 or later.
2406 * Two new commands have been added for record/replay to give information
2407 about the recorded execution without having to replay the execution.
2408 The commands are only supported by "record btrace".
2410 record instruction-history prints the execution history at
2411 instruction granularity
2413 record function-call-history prints the execution history at
2414 function granularity
2416 * New native configurations
2418 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2419 FreeBSD/powerpc powerpc*-*-freebsd
2420 x86_64/Cygwin x86_64-*-cygwin*
2421 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2425 ARM AArch64 aarch64*-*-elf
2426 ARM AArch64 GNU/Linux aarch64*-*-linux
2427 Lynx 178 PowerPC powerpc-*-lynx*178
2428 x86_64/Cygwin x86_64-*-cygwin*
2429 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2431 * If the configured location of system.gdbinit file (as given by the
2432 --with-system-gdbinit option at configure time) is in the
2433 data-directory (as specified by --with-gdb-datadir at configure
2434 time) or in one of its subdirectories, then GDB will look for the
2435 system-wide init file in the directory specified by the
2436 --data-directory command-line option.
2438 * New command line options:
2440 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2441 other initialization files, unlike -nx which disables all of them.
2443 * Removed command line options
2445 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2448 * The 'ptype' and 'whatis' commands now accept an argument to control
2451 * 'info proc' now works on some core files.
2455 ** Vectors can be created with gdb.Type.vector.
2457 ** Python's atexit.register now works in GDB.
2459 ** Types can be pretty-printed via a Python API.
2461 ** Python 3 is now supported (in addition to Python 2.4 or later)
2463 ** New class gdb.Architecture exposes GDB's internal representation
2464 of architecture in the Python API.
2466 ** New method Frame.architecture returns the gdb.Architecture object
2467 corresponding to the frame's architecture.
2469 * New Python-based convenience functions:
2471 ** $_memeq(buf1, buf2, length)
2472 ** $_streq(str1, str2)
2474 ** $_regex(str, regex)
2476 * The 'cd' command now defaults to using '~' (the home directory) if not
2479 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2480 default for GCC since November 2000.
2482 * The command 'forward-search' can now be abbreviated as 'fo'.
2484 * The command 'info tracepoints' can now display 'installed on target'
2485 or 'not installed on target' for each non-pending location of tracepoint.
2487 * New configure options
2489 --enable-libmcheck/--disable-libmcheck
2490 By default, development versions are built with -lmcheck on hosts
2491 that support it, in order to help track memory corruption issues.
2492 Release versions, on the other hand, are built without -lmcheck
2493 by default. The --enable-libmcheck/--disable-libmcheck configure
2494 options allow the user to override that default.
2495 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2496 This configure option allows the user to build GDB with
2497 libbabeltrace using which GDB can read Common Trace Format data.
2499 * New commands (for set/show, see "New options" below)
2502 Catch signals. This is similar to "handle", but allows commands and
2503 conditions to be attached.
2506 List the BFDs known to GDB.
2508 python-interactive [command]
2510 Start a Python interactive prompt, or evaluate the optional command
2511 and print the result of expressions.
2514 "py" is a new alias for "python".
2516 enable type-printer [name]...
2517 disable type-printer [name]...
2518 Enable or disable type printers.
2522 ** For the Renesas Super-H architecture, the "regs" command has been removed
2523 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2528 set print type methods (on|off)
2529 show print type methods
2530 Control whether method declarations are displayed by "ptype".
2531 The default is to show them.
2533 set print type typedefs (on|off)
2534 show print type typedefs
2535 Control whether typedef definitions are displayed by "ptype".
2536 The default is to show them.
2538 set filename-display basename|relative|absolute
2539 show filename-display
2540 Control the way in which filenames is displayed.
2541 The default is "relative", which preserves previous behavior.
2543 set trace-buffer-size
2544 show trace-buffer-size
2545 Request target to change the size of trace buffer.
2547 set remote trace-buffer-size-packet auto|on|off
2548 show remote trace-buffer-size-packet
2549 Control the use of the remote protocol `QTBuffer:size' packet.
2553 Control display of debugging messages related to ARM AArch64.
2556 set debug coff-pe-read
2557 show debug coff-pe-read
2558 Control display of debugging messages related to reading of COFF/PE
2563 Control display of debugging messages related to Mach-O symbols
2566 set debug notification
2567 show debug notification
2568 Control display of debugging info for async remote notification.
2572 ** Command parameter changes are now notified using new async record
2573 "=cmd-param-changed".
2574 ** Trace frame changes caused by command "tfind" are now notified using
2575 new async record "=traceframe-changed".
2576 ** The creation, deletion and modification of trace state variables
2577 are now notified using new async records "=tsv-created",
2578 "=tsv-deleted" and "=tsv-modified".
2579 ** The start and stop of process record are now notified using new
2580 async record "=record-started" and "=record-stopped".
2581 ** Memory changes are now notified using new async record
2583 ** The data-disassemble command response will include a "fullname" field
2584 containing the absolute file name when source has been requested.
2585 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2586 command, to allow pattern filling of memory areas.
2587 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2588 library load/unload events.
2589 ** The response to breakpoint commands and breakpoint async records
2590 includes an "installed" field containing a boolean state about each
2591 non-pending tracepoint location is whether installed on target or not.
2592 ** Output of the "-trace-status" command includes a "trace-file" field
2593 containing the name of the trace file being examined. This field is
2594 optional, and only present when examining a trace file.
2595 ** The "fullname" field is now always present along with the "file" field,
2596 even if the file cannot be found by GDB.
2598 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2599 You must have the LZMA library available when configuring GDB for this
2600 feature to be enabled. For more information, see:
2601 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2603 * New remote packets
2606 Set the size of trace buffer. The remote stub reports support for this
2607 packet to gdb's qSupported query.
2610 Enable Branch Trace Store (BTS)-based branch tracing for the current
2611 thread. The remote stub reports support for this packet to gdb's
2615 Disable branch tracing for the current thread. The remote stub reports
2616 support for this packet to gdb's qSupported query.
2619 Read the traced branches for the current thread. The remote stub
2620 reports support for this packet to gdb's qSupported query.
2622 *** Changes in GDB 7.5
2624 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2625 for more x32 ABI info.
2627 * GDB now supports access to MIPS DSP registers on Linux targets.
2629 * GDB now supports debugging microMIPS binaries.
2631 * The "info os" command on GNU/Linux can now display information on
2632 several new classes of objects managed by the operating system:
2633 "info os procgroups" lists process groups
2634 "info os files" lists file descriptors
2635 "info os sockets" lists internet-domain sockets
2636 "info os shm" lists shared-memory regions
2637 "info os semaphores" lists semaphores
2638 "info os msg" lists message queues
2639 "info os modules" lists loaded kernel modules
2641 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2642 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2643 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2644 options and inspect the probe arguments using the new $_probe_arg family
2645 of convenience variables. You can obtain more information about SystemTap
2646 in <http://sourceware.org/systemtap/>.
2648 * GDB now supports reversible debugging on ARM, it allows you to
2649 debug basic ARM and THUMB instructions, and provides
2650 record/replay support.
2652 * The option "symbol-reloading" has been deleted as it is no longer used.
2656 ** GDB commands implemented in Python can now be put in command class
2659 ** The "maint set python print-stack on|off" is now deleted.
2661 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2662 apply "flag enum"-style pretty-printing to any enum.
2664 ** gdb.lookup_symbol can now work when there is no current frame.
2666 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2667 the source at which the symbol was defined.
2669 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2670 method 'value'. The former indicates whether the symbol needs a
2671 frame in order to compute its value, and the latter computes the
2674 ** A new method 'referenced_value' on gdb.Value objects which can
2675 dereference pointer as well as C++ reference values.
2677 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2678 which return the global and static blocks (as gdb.Block objects),
2679 of the underlying symbol table, respectively.
2681 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2682 object associated with a PC value.
2684 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2685 of the address range occupied by code for the current source line.
2687 * Go language support.
2688 GDB now supports debugging programs written in the Go programming
2691 * GDBserver now supports stdio connections.
2692 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2694 * The binary "gdbtui" can no longer be built or installed.
2695 Use "gdb -tui" instead.
2697 * GDB will now print "flag" enums specially. A flag enum is one where
2698 all the enumerator values have no bits in common when pairwise
2699 "and"ed. When printing a value whose type is a flag enum, GDB will
2700 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2701 (gdb) print (enum E) 3
2704 * The filename part of a linespec will now match trailing components
2705 of a source file name. For example, "break gcc/expr.c:1000" will
2706 now set a breakpoint in build/gcc/expr.c, but not
2707 build/libcpp/expr.c.
2709 * The "info proc" and "generate-core-file" commands will now also
2710 work on remote targets connected to GDBserver on Linux.
2712 * The command "info catch" has been removed. It has been disabled
2713 since December 2007.
2715 * The "catch exception" and "catch assert" commands now accept
2716 a condition at the end of the command, much like the "break"
2717 command does. For instance:
2719 (gdb) catch exception Constraint_Error if Barrier = True
2721 Previously, it was possible to add a condition to such catchpoints,
2722 but it had to be done as a second step, after the catchpoint had been
2723 created, using the "condition" command.
2725 * The "info static-tracepoint-marker" command will now also work on
2726 native Linux targets with in-process agent.
2728 * GDB can now set breakpoints on inlined functions.
2730 * The .gdb_index section has been updated to include symbols for
2731 inlined functions. GDB will ignore older .gdb_index sections by
2732 default, which could cause symbol files to be loaded more slowly
2733 until their .gdb_index sections can be recreated. The new command
2734 "set use-deprecated-index-sections on" will cause GDB to use any older
2735 .gdb_index sections it finds. This will restore performance, but the
2736 ability to set breakpoints on inlined functions will be lost in symbol
2737 files with older .gdb_index sections.
2739 The .gdb_index section has also been updated to record more information
2740 about each symbol. This speeds up the "info variables", "info functions"
2741 and "info types" commands when used with programs having the .gdb_index
2742 section, as well as speeding up debugging with shared libraries using
2743 the .gdb_index section.
2745 * Ada support for GDB/MI Variable Objects has been added.
2747 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2752 ** New command -info-os is the MI equivalent of "info os".
2754 ** Output logs ("set logging" and related) now include MI output.
2758 ** "set use-deprecated-index-sections on|off"
2759 "show use-deprecated-index-sections on|off"
2760 Controls the use of deprecated .gdb_index sections.
2762 ** "catch load" and "catch unload" can be used to stop when a shared
2763 library is loaded or unloaded, respectively.
2765 ** "enable count" can be used to auto-disable a breakpoint after
2768 ** "info vtbl" can be used to show the virtual method tables for
2769 C++ and Java objects.
2771 ** "explore" and its sub commands "explore value" and "explore type"
2772 can be used to recursively explore values and types of
2773 expressions. These commands are available only if GDB is
2774 configured with '--with-python'.
2776 ** "info auto-load" shows status of all kinds of auto-loaded files,
2777 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2778 sequences of commands files, "info auto-load python-scripts"
2779 shows status of auto-loading Python script files,
2780 "info auto-load local-gdbinit" shows status of loading init file
2781 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2782 status of inferior specific thread debugging shared library loading.
2784 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2785 and "show auto-load-scripts" commands have been deprecated, use their
2786 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2787 and "show auto-load python-scripts" counterparts instead.
2789 ** "dprintf location,format,args..." creates a dynamic printf, which
2790 is basically a breakpoint that does a printf and immediately
2791 resumes your program's execution, so it is like a printf that you
2792 can insert dynamically at runtime instead of at compiletime.
2794 ** "set print symbol"
2796 Controls whether GDB attempts to display the symbol, if any,
2797 corresponding to addresses it prints. This defaults to "on", but
2798 you can set it to "off" to restore GDB's previous behavior.
2800 * Deprecated commands
2802 ** For the Renesas Super-H architecture, the "regs" command has been
2803 deprecated, and "info all-registers" should be used instead.
2807 Renesas RL78 rl78-*-elf
2808 HP OpenVMS ia64 ia64-hp-openvms*
2810 * GDBserver supports evaluation of breakpoint conditions. When
2811 support is advertised by GDBserver, GDB may be told to send the
2812 breakpoint conditions in bytecode form to GDBserver. GDBserver
2813 will only report the breakpoint trigger to GDB when its condition
2818 set mips compression
2819 show mips compression
2820 Select the compressed ISA encoding used in functions that have no symbol
2821 information available. The encoding can be set to either of:
2824 and is updated automatically from ELF file flags if available.
2826 set breakpoint condition-evaluation
2827 show breakpoint condition-evaluation
2828 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2829 GDBserver ("target"). Default option "auto" chooses the most efficient
2831 This option can improve debugger efficiency depending on the speed of the
2835 Disable auto-loading globally.
2838 Show auto-loading setting of all kinds of auto-loaded files.
2840 set auto-load gdb-scripts on|off
2841 show auto-load gdb-scripts
2842 Control auto-loading of GDB canned sequences of commands files.
2844 set auto-load python-scripts on|off
2845 show auto-load python-scripts
2846 Control auto-loading of Python script files.
2848 set auto-load local-gdbinit on|off
2849 show auto-load local-gdbinit
2850 Control loading of init file (.gdbinit) from current directory.
2852 set auto-load libthread-db on|off
2853 show auto-load libthread-db
2854 Control auto-loading of inferior specific thread debugging shared library.
2856 set auto-load scripts-directory <dir1>[:<dir2>...]
2857 show auto-load scripts-directory
2858 Set a list of directories from which to load auto-loaded scripts.
2859 Automatically loaded Python scripts and GDB scripts are located in one
2860 of the directories listed by this option.
2861 The delimiter (':' above) may differ according to the host platform.
2863 set auto-load safe-path <dir1>[:<dir2>...]
2864 show auto-load safe-path
2865 Set a list of directories from which it is safe to auto-load files.
2866 The delimiter (':' above) may differ according to the host platform.
2868 set debug auto-load on|off
2869 show debug auto-load
2870 Control display of debugging info for auto-loading the files above.
2872 set dprintf-style gdb|call|agent
2874 Control the way in which a dynamic printf is performed; "gdb"
2875 requests a GDB printf command, while "call" causes dprintf to call a
2876 function in the inferior. "agent" requests that the target agent
2877 (such as GDBserver) do the printing.
2879 set dprintf-function <expr>
2880 show dprintf-function
2881 set dprintf-channel <expr>
2882 show dprintf-channel
2883 Set the function and optional first argument to the call when using
2884 the "call" style of dynamic printf.
2886 set disconnected-dprintf on|off
2887 show disconnected-dprintf
2888 Control whether agent-style dynamic printfs continue to be in effect
2889 after GDB disconnects.
2891 * New configure options
2893 --with-auto-load-dir
2894 Configure default value for the 'set auto-load scripts-directory'
2895 setting above. It defaults to '$debugdir:$datadir/auto-load',
2896 $debugdir representing global debugging info directories (available
2897 via 'show debug-file-directory') and $datadir representing GDB's data
2898 directory (available via 'show data-directory').
2900 --with-auto-load-safe-path
2901 Configure default value for the 'set auto-load safe-path' setting
2902 above. It defaults to the --with-auto-load-dir setting.
2904 --without-auto-load-safe-path
2905 Set 'set auto-load safe-path' to '/', effectively disabling this
2908 * New remote packets
2910 z0/z1 conditional breakpoints extension
2912 The z0/z1 breakpoint insertion packets have been extended to carry
2913 a list of conditional expressions over to the remote stub depending on the
2914 condition evaluation mode. The use of this extension can be controlled
2915 via the "set remote conditional-breakpoints-packet" command.
2919 Specify the signals which the remote stub may pass to the debugged
2920 program without GDB involvement.
2922 * New command line options
2924 --init-command=FILE, -ix Like --command, -x but execute it
2925 before loading inferior.
2926 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2927 execute it before loading inferior.
2929 *** Changes in GDB 7.4
2931 * GDB now handles ambiguous linespecs more consistently; the existing
2932 FILE:LINE support has been expanded to other types of linespecs. A
2933 breakpoint will now be set on all matching locations in all
2934 inferiors, and locations will be added or removed according to
2937 * GDB now allows you to skip uninteresting functions and files when
2938 stepping with the "skip function" and "skip file" commands.
2940 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2941 and "show remote hardware-watchpoint-length-limit". These allows to
2942 set or show the maximum length limit (in bytes) of a remote
2943 target hardware watchpoint.
2945 This allows e.g. to use "unlimited" hardware watchpoints with the
2946 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2947 watchpoints are slower than real hardware watchpoints but are
2948 significantly faster than gdb software watchpoints.
2952 ** The register_pretty_printer function in module gdb.printing now takes
2953 an optional `replace' argument. If True, the new printer replaces any
2956 ** The "maint set python print-stack on|off" command has been
2957 deprecated and will be deleted in GDB 7.5.
2958 A new command: "set python print-stack none|full|message" has
2959 replaced it. Additionally, the default for "print-stack" is
2960 now "message", which just prints the error message without
2963 ** A prompt substitution hook (prompt_hook) is now available to the
2966 ** A new Python module, gdb.prompt has been added to the GDB Python
2967 modules library. This module provides functionality for
2968 escape sequences in prompts (used by set/show
2969 extended-prompt). These escape sequences are replaced by their
2970 corresponding value.
2972 ** Python commands and convenience-functions located in
2973 'data-directory'/python/gdb/command and
2974 'data-directory'/python/gdb/function are now automatically loaded
2977 ** Blocks now provide four new attributes. global_block and
2978 static_block will return the global and static blocks
2979 respectively. is_static and is_global are boolean attributes
2980 that indicate if the block is one of those two types.
2982 ** Symbols now provide the "type" attribute, the type of the symbol.
2984 ** The "gdb.breakpoint" function has been deprecated in favor of
2987 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2988 of a function. This class is based on the "finish" command
2989 available in the CLI.
2991 ** Type objects for struct and union types now allow access to
2992 the fields using standard Python dictionary (mapping) methods.
2993 For example, "some_type['myfield']" now works, as does
2994 "some_type.items()".
2996 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2999 ** A new function, "deep_items" has been added to the gdb.types
3000 module in the GDB Python modules library. This function returns
3001 an iterator over the fields of a struct or union type. Unlike
3002 the standard Python "iteritems" method, it will recursively traverse
3003 any anonymous fields.
3007 ** "*stopped" events can report several new "reason"s, such as
3010 ** Breakpoint changes are now notified using new async records, like
3011 "=breakpoint-modified".
3013 ** New command -ada-task-info.
3015 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3016 $sdir specifies the default system locations of shared libraries.
3017 $pdir specifies the directory where the libpthread used by the application
3020 GDB no longer looks in $sdir and $pdir after it has searched the directories
3021 mentioned in libthread-db-search-path. If you want to search those
3022 directories, they must be specified in libthread-db-search-path.
3023 The default value of libthread-db-search-path on GNU/Linux and Solaris
3024 systems is now "$sdir:$pdir".
3026 $pdir is not supported by gdbserver, it is currently ignored.
3027 $sdir is supported by gdbserver.
3029 * New configure option --with-iconv-bin.
3030 When using the internationalization support like the one in the GNU C
3031 library, GDB will invoke the "iconv" program to get a list of supported
3032 character sets. If this program lives in a non-standard location, one can
3033 use this option to specify where to find it.
3035 * When natively debugging programs on PowerPC BookE processors running
3036 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3037 watchpoints, which specify a mask in addition to an address to watch.
3038 The mask specifies that some bits of an address (the bits which are
3039 reset in the mask) should be ignored when matching the address accessed
3040 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3041 section in the user manual for more details.
3043 * The new option --once causes GDBserver to stop listening for connections once
3044 the first connection is made. The listening port used by GDBserver will
3045 become available after that.
3047 * New commands "info macros" and "alias" have been added.
3049 * New function parameters suffix @entry specifies value of function parameter
3050 at the time the function got called. Entry values are available only since
3056 "!" is now an alias of the "shell" command.
3057 Note that no space is needed between "!" and SHELL COMMAND.
3061 watch EXPRESSION mask MASK_VALUE
3062 The watch command now supports the mask argument which allows creation
3063 of masked watchpoints, if the current architecture supports this feature.
3065 info auto-load-scripts [REGEXP]
3066 This command was formerly named "maintenance print section-scripts".
3067 It is now generally useful and is no longer a maintenance-only command.
3069 info macro [-all] [--] MACRO
3070 The info macro command has new options `-all' and `--'. The first for
3071 printing all definitions of a macro. The second for explicitly specifying
3072 the end of arguments and the beginning of the macro name in case the macro
3073 name starts with a hyphen.
3075 collect[/s] EXPRESSIONS
3076 The tracepoint collect command now takes an optional modifier "/s"
3077 that directs it to dereference pointer-to-character types and
3078 collect the bytes of memory up to a zero byte. The behavior is
3079 similar to what you see when you use the regular print command on a
3080 string. An optional integer following the "/s" sets a bound on the
3081 number of bytes that will be collected.
3084 The trace start command now interprets any supplied arguments as a
3085 note to be recorded with the trace run, with an effect similar to
3086 setting the variable trace-notes.
3089 The trace stop command now interprets any arguments as a note to be
3090 mentioned along with the tstatus report that the trace was stopped
3091 with a command. The effect is similar to setting the variable
3094 * Tracepoints can now be enabled and disabled at any time after a trace
3095 experiment has been started using the standard "enable" and "disable"
3096 commands. It is now possible to start a trace experiment with no enabled
3097 tracepoints; GDB will display a warning, but will allow the experiment to
3098 begin, assuming that tracepoints will be enabled as needed while the trace
3101 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3102 locations with 4-byte instructions, when they were previously
3103 limited to locations with instructions of 5 bytes or longer.
3107 set debug dwarf2-read
3108 show debug dwarf2-read
3109 Turns on or off display of debugging messages related to reading
3110 DWARF debug info. The default is off.
3112 set debug symtab-create
3113 show debug symtab-create
3114 Turns on or off display of debugging messages related to symbol table
3115 creation. The default is off.
3118 show extended-prompt
3119 Set the GDB prompt, and allow escape sequences to be inserted to
3120 display miscellaneous information (see 'help set extended-prompt'
3121 for the list of sequences). This prompt (and any information
3122 accessed through the escape sequences) is updated every time the
3123 prompt is displayed.
3125 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3126 show print entry-values
3127 Set printing of frame argument values at function entry. In some cases
3128 GDB can determine the value of function argument which was passed by the
3129 function caller, even if the value was modified inside the called function.
3131 set debug entry-values
3132 show debug entry-values
3133 Control display of debugging info for determining frame argument values at
3134 function entry and virtual tail call frames.
3136 set basenames-may-differ
3137 show basenames-may-differ
3138 Set whether a source file may have multiple base names.
3139 (A "base name" is the name of a file with the directory part removed.
3140 Example: The base name of "/home/user/hello.c" is "hello.c".)
3141 If set, GDB will canonicalize file names (e.g., expand symlinks)
3142 before comparing them. Canonicalization is an expensive operation,
3143 but it allows the same file be known by more than one base name.
3144 If not set (the default), all source files are assumed to have just
3145 one base name, and gdb will do file name comparisons more efficiently.
3151 Set a user name and notes for the current and any future trace runs.
3152 This is useful for long-running and/or disconnected traces, to
3153 inform others (or yourself) as to who is running the trace, supply
3154 contact information, or otherwise explain what is going on.
3156 set trace-stop-notes
3157 show trace-stop-notes
3158 Set a note attached to the trace run, that is displayed when the
3159 trace has been stopped by a tstop command. This is useful for
3160 instance as an explanation, if you are stopping a trace run that was
3161 started by someone else.
3163 * New remote packets
3167 Dynamically enable a tracepoint in a started trace experiment.
3171 Dynamically disable a tracepoint in a started trace experiment.
3175 Set the user and notes of the trace run.
3179 Query the current status of a tracepoint.
3183 Query the minimum length of instruction at which a fast tracepoint may
3186 * Dcache size (number of lines) and line-size are now runtime-configurable
3187 via "set dcache line" and "set dcache line-size" commands.
3191 Texas Instruments TMS320C6x tic6x-*-*
3195 Renesas RL78 rl78-*-elf
3197 *** Changes in GDB 7.3.1
3199 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3201 *** Changes in GDB 7.3
3203 * GDB has a new command: "thread find [REGEXP]".
3204 It finds the thread id whose name, target id, or thread extra info
3205 matches the given regular expression.
3207 * The "catch syscall" command now works on mips*-linux* targets.
3209 * The -data-disassemble MI command now supports modes 2 and 3 for
3210 dumping the instruction opcodes.
3212 * New command line options
3214 -data-directory DIR Specify DIR as the "data-directory".
3215 This is mostly for testing purposes.
3217 * The "maint set python auto-load on|off" command has been renamed to
3218 "set auto-load-scripts on|off".
3220 * GDB has a new command: "set directories".
3221 It is like the "dir" command except that it replaces the
3222 source path list instead of augmenting it.
3224 * GDB now understands thread names.
3226 On GNU/Linux, "info threads" will display the thread name as set by
3227 prctl or pthread_setname_np.
3229 There is also a new command, "thread name", which can be used to
3230 assign a name internally for GDB to display.
3233 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3234 has been integrated into GDB.
3238 ** The function gdb.Write now accepts an optional keyword 'stream'.
3239 This keyword, when provided, will direct the output to either
3240 stdout, stderr, or GDB's logging output.
3242 ** Parameters can now be be sub-classed in Python, and in particular
3243 you may implement the get_set_doc and get_show_doc functions.
3244 This improves how Parameter set/show documentation is processed
3245 and allows for more dynamic content.
3247 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3248 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3249 have an is_valid method.
3251 ** Breakpoints can now be sub-classed in Python, and in particular
3252 you may implement a 'stop' function that is executed each time
3253 the inferior reaches that breakpoint.
3255 ** New function gdb.lookup_global_symbol looks up a global symbol.
3257 ** GDB values in Python are now callable if the value represents a
3258 function. For example, if 'some_value' represents a function that
3259 takes two integer parameters and returns a value, you can call
3260 that function like so:
3262 result = some_value (10,20)
3264 ** Module gdb.types has been added.
3265 It contains a collection of utilities for working with gdb.Types objects:
3266 get_basic_type, has_field, make_enum_dict.
3268 ** Module gdb.printing has been added.
3269 It contains utilities for writing and registering pretty-printers.
3270 New classes: PrettyPrinter, SubPrettyPrinter,
3271 RegexpCollectionPrettyPrinter.
3272 New function: register_pretty_printer.
3274 ** New commands "info pretty-printers", "enable pretty-printer" and
3275 "disable pretty-printer" have been added.
3277 ** gdb.parameter("directories") is now available.
3279 ** New function gdb.newest_frame returns the newest frame in the
3282 ** The gdb.InferiorThread class has a new "name" attribute. This
3283 holds the thread's name.
3285 ** Python Support for Inferior events.
3286 Python scripts can add observers to be notified of events
3287 occurring in the process being debugged.
3288 The following events are currently supported:
3289 - gdb.events.cont Continue event.
3290 - gdb.events.exited Inferior exited event.
3291 - gdb.events.stop Signal received, and Breakpoint hit events.
3295 ** GDB now puts template parameters in scope when debugging in an
3296 instantiation. For example, if you have:
3298 template<int X> int func (void) { return X; }
3300 then if you step into func<5>, "print X" will show "5". This
3301 feature requires proper debuginfo support from the compiler; it
3302 was added to GCC 4.5.
3304 ** The motion commands "next", "finish", "until", and "advance" now
3305 work better when exceptions are thrown. In particular, GDB will
3306 no longer lose control of the inferior; instead, the GDB will
3307 stop the inferior at the point at which the exception is caught.
3308 This functionality requires a change in the exception handling
3309 code that was introduced in GCC 4.5.
3311 * GDB now follows GCC's rules on accessing volatile objects when
3312 reading or writing target state during expression evaluation.
3313 One notable difference to prior behavior is that "print x = 0"
3314 no longer generates a read of x; the value of the assignment is
3315 now always taken directly from the value being assigned.
3317 * GDB now has some support for using labels in the program's source in
3318 linespecs. For instance, you can use "advance label" to continue
3319 execution to a label.
3321 * GDB now has support for reading and writing a new .gdb_index
3322 section. This section holds a fast index of DWARF debugging
3323 information and can be used to greatly speed up GDB startup and
3324 operation. See the documentation for `save gdb-index' for details.
3326 * The "watch" command now accepts an optional "-location" argument.
3327 When used, this causes GDB to watch the memory referred to by the
3328 expression. Such a watchpoint is never deleted due to it going out
3331 * GDB now supports thread debugging of core dumps on GNU/Linux.
3333 GDB now activates thread debugging using the libthread_db library
3334 when debugging GNU/Linux core dumps, similarly to when debugging
3335 live processes. As a result, when debugging a core dump file, GDB
3336 is now able to display pthread_t ids of threads. For example, "info
3337 threads" shows the same output as when debugging the process when it
3338 was live. In earlier releases, you'd see something like this:
3341 * 1 LWP 6780 main () at main.c:10
3343 While now you see this:
3346 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3348 It is also now possible to inspect TLS variables when debugging core
3351 When debugging a core dump generated on a machine other than the one
3352 used to run GDB, you may need to point GDB at the correct
3353 libthread_db library with the "set libthread-db-search-path"
3354 command. See the user manual for more details on this command.
3356 * When natively debugging programs on PowerPC BookE processors running
3357 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3358 which stop execution of the inferior whenever it executes an instruction
3359 at any address within the specified range. See the "PowerPC Embedded"
3360 section in the user manual for more details.
3362 * New features in the GDB remote stub, GDBserver
3364 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3365 and i686 LynxOS (version 5.x).
3367 ** GDBserver is now supported on Blackfin Linux.
3369 * New native configurations
3371 ia64 HP-UX ia64-*-hpux*
3375 Analog Devices, Inc. Blackfin Processor bfin-*
3377 * Ada task switching is now supported on sparc-elf targets when
3378 debugging a program using the Ravenscar Profile. For more information,
3379 see the "Tasking Support when using the Ravenscar Profile" section
3380 in the GDB user manual.
3382 * Guile support was removed.
3384 * New features in the GNU simulator
3386 ** The --map-info flag lists all known core mappings.
3388 ** CFI flashes may be simulated via the "cfi" device.
3390 *** Changes in GDB 7.2
3392 * Shared library support for remote targets by default
3394 When GDB is configured for a generic, non-OS specific target, like
3395 for example, --target=arm-eabi or one of the many *-*-elf targets,
3396 GDB now queries remote stubs for loaded shared libraries using the
3397 `qXfer:libraries:read' packet. Previously, shared library support
3398 was always disabled for such configurations.
3402 ** Argument Dependent Lookup (ADL)
3404 In C++ ADL lookup directs function search to the namespaces of its
3405 arguments even if the namespace has not been imported.
3415 Here the compiler will search for `foo' in the namespace of 'b'
3416 and find A::foo. GDB now supports this. This construct is commonly
3417 used in the Standard Template Library for operators.
3419 ** Improved User Defined Operator Support
3421 In addition to member operators, GDB now supports lookup of operators
3422 defined in a namespace and imported with a `using' directive, operators
3423 defined in the global scope, operators imported implicitly from an
3424 anonymous namespace, and the ADL operators mentioned in the previous
3426 GDB now also supports proper overload resolution for all the previously
3427 mentioned flavors of operators.
3429 ** static const class members
3431 Printing of static const class members that are initialized in the
3432 class definition has been fixed.
3434 * Windows Thread Information Block access.
3436 On Windows targets, GDB now supports displaying the Windows Thread
3437 Information Block (TIB) structure. This structure is visible either
3438 by using the new command `info w32 thread-information-block' or, by
3439 dereferencing the new convenience variable named `$_tlb', a
3440 thread-specific pointer to the TIB. This feature is also supported
3441 when remote debugging using GDBserver.
3443 * Static tracepoints
3445 Static tracepoints are calls in the user program into a tracing
3446 library. One such library is a port of the LTTng kernel tracer to
3447 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3448 When debugging with GDBserver, GDB now supports combining the GDB
3449 tracepoint machinery with such libraries. For example: the user can
3450 use GDB to probe a static tracepoint marker (a call from the user
3451 program into the tracing library) with the new "strace" command (see
3452 "New commands" below). This creates a "static tracepoint" in the
3453 breakpoint list, that can be manipulated with the same feature set
3454 as fast and regular tracepoints. E.g., collect registers, local and
3455 global variables, collect trace state variables, and define
3456 tracepoint conditions. In addition, the user can collect extra
3457 static tracepoint marker specific data, by collecting the new
3458 $_sdata internal variable. When analyzing the trace buffer, you can
3459 inspect $_sdata like any other variable available to GDB. For more
3460 information, see the "Tracepoints" chapter in GDB user manual. New
3461 remote packets have been defined to support static tracepoints, see
3462 the "New remote packets" section below.
3464 * Better reconstruction of tracepoints after disconnected tracing
3466 GDB will attempt to download the original source form of tracepoint
3467 definitions when starting a trace run, and then will upload these
3468 upon reconnection to the target, resulting in a more accurate
3469 reconstruction of the tracepoints that are in use on the target.
3473 You can now exercise direct control over the ways that GDB can
3474 affect your program. For instance, you can disallow the setting of
3475 breakpoints, so that the program can run continuously (assuming
3476 non-stop mode). In addition, the "observer" variable is available
3477 to switch all of the different controls; in observer mode, GDB
3478 cannot affect the target's behavior at all, which is useful for
3479 tasks like diagnosing live systems in the field.
3481 * The new convenience variable $_thread holds the number of the
3484 * New remote packets
3488 Return the address of the Windows Thread Information Block of a given thread.
3492 In response to several of the tracepoint packets, the target may now
3493 also respond with a number of intermediate `qRelocInsn' request
3494 packets before the final result packet, to have GDB handle
3495 relocating an instruction to execute at a different address. This
3496 is particularly useful for stubs that support fast tracepoints. GDB
3497 reports support for this feature in the qSupported packet.
3501 List static tracepoint markers in the target program.
3505 List static tracepoint markers at a given address in the target
3508 qXfer:statictrace:read
3510 Read the static trace data collected (by a `collect $_sdata'
3511 tracepoint action). The remote stub reports support for this packet
3512 to gdb's qSupported query.
3516 Send the current settings of GDB's permission flags.
3520 Send part of the source (textual) form of a tracepoint definition,
3521 which includes location, conditional, and action list.
3523 * The source command now accepts a -s option to force searching for the
3524 script in the source search path even if the script name specifies
3527 * New features in the GDB remote stub, GDBserver
3529 - GDBserver now support tracepoints (including fast tracepoints, and
3530 static tracepoints). The feature is currently supported by the
3531 i386-linux and amd64-linux builds. See the "Tracepoints support
3532 in gdbserver" section in the manual for more information.
3534 GDBserver JIT compiles the tracepoint's conditional agent
3535 expression bytecode into native code whenever possible for low
3536 overhead dynamic tracepoints conditionals. For such tracepoints,
3537 an expression that examines program state is evaluated when the
3538 tracepoint is reached, in order to determine whether to capture
3539 trace data. If the condition is simple and false, processing the
3540 tracepoint finishes very quickly and no data is gathered.
3542 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3543 for static tracepoints support.
3545 - GDBserver now supports x86_64 Windows 64-bit debugging.
3547 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3548 it understands register description.
3550 * The --batch flag now disables pagination and queries.
3552 * X86 general purpose registers
3554 GDB now supports reading/writing byte, word and double-word x86
3555 general purpose registers directly. This means you can use, say,
3556 $ah or $ax to refer, respectively, to the byte register AH and
3557 16-bit word register AX that are actually portions of the 32-bit
3558 register EAX or 64-bit register RAX.
3560 * The `commands' command now accepts a range of breakpoints to modify.
3561 A plain `commands' following a command that creates multiple
3562 breakpoints affects all the breakpoints set by that command. This
3563 applies to breakpoints set by `rbreak', and also applies when a
3564 single `break' command creates multiple breakpoints (e.g.,
3565 breakpoints on overloaded c++ functions).
3567 * The `rbreak' command now accepts a filename specification as part of
3568 its argument, limiting the functions selected by the regex to those
3569 in the specified file.
3571 * Support for remote debugging Windows and SymbianOS shared libraries
3572 from Unix hosts has been improved. Non Windows GDB builds now can
3573 understand target reported file names that follow MS-DOS based file
3574 system semantics, such as file names that include drive letters and
3575 use the backslash character as directory separator. This makes it
3576 possible to transparently use the "set sysroot" and "set
3577 solib-search-path" on Unix hosts to point as host copies of the
3578 target's shared libraries. See the new command "set
3579 target-file-system-kind" described below, and the "Commands to
3580 specify files" section in the user manual for more information.
3584 eval template, expressions...
3585 Convert the values of one or more expressions under the control
3586 of the string template to a command line, and call it.
3588 set target-file-system-kind unix|dos-based|auto
3589 show target-file-system-kind
3590 Set or show the assumed file system kind for target reported file
3593 save breakpoints <filename>
3594 Save all current breakpoint definitions to a file suitable for use
3595 in a later debugging session. To read the saved breakpoint
3596 definitions, use the `source' command.
3598 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3601 info static-tracepoint-markers
3602 Display information about static tracepoint markers in the target.
3604 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3605 Define a static tracepoint by probing a marker at the given
3606 function, line, address, or marker ID.
3610 Enable and disable observer mode.
3612 set may-write-registers on|off
3613 set may-write-memory on|off
3614 set may-insert-breakpoints on|off
3615 set may-insert-tracepoints on|off
3616 set may-insert-fast-tracepoints on|off
3617 set may-interrupt on|off
3618 Set individual permissions for GDB effects on the target. Note that
3619 some of these settings can have undesirable or surprising
3620 consequences, particularly when changed in the middle of a session.
3621 For instance, disabling the writing of memory can prevent
3622 breakpoints from being inserted, cause single-stepping to fail, or
3623 even crash your program, if you disable after breakpoints have been
3624 inserted. However, GDB should not crash.
3626 set record memory-query on|off
3627 show record memory-query
3628 Control whether to stop the inferior if memory changes caused
3629 by an instruction cannot be recorded.
3634 The disassemble command now supports "start,+length" form of two arguments.
3638 ** GDB now provides a new directory location, called the python directory,
3639 where Python scripts written for GDB can be installed. The location
3640 of that directory is <data-directory>/python, where <data-directory>
3641 is the GDB data directory. For more details, see section `Scripting
3642 GDB using Python' in the manual.
3644 ** The GDB Python API now has access to breakpoints, symbols, symbol
3645 tables, program spaces, inferiors, threads and frame's code blocks.
3646 Additionally, GDB Parameters can now be created from the API, and
3647 manipulated via set/show in the CLI.
3649 ** New functions gdb.target_charset, gdb.target_wide_charset,
3650 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3652 ** New exception gdb.GdbError.
3654 ** Pretty-printers are now also looked up in the current program space.
3656 ** Pretty-printers can now be individually enabled and disabled.
3658 ** GDB now looks for names of Python scripts to auto-load in a
3659 special section named `.debug_gdb_scripts', in addition to looking
3660 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3662 * Tracepoint actions were unified with breakpoint commands. In particular,
3663 there are no longer differences in "info break" output for breakpoints and
3664 tracepoints and the "commands" command can be used for both tracepoints and
3665 regular breakpoints.
3669 ARM Symbian arm*-*-symbianelf*
3671 * D language support.
3672 GDB now supports debugging programs written in the D programming
3675 * GDB now supports the extended ptrace interface for PowerPC which is
3676 available since Linux kernel version 2.6.34. This automatically enables
3677 any hardware breakpoints and additional hardware watchpoints available in
3678 the processor. The old ptrace interface exposes just one hardware
3679 watchpoint and no hardware breakpoints.
3681 * GDB is now able to use the Data Value Compare (DVC) register available on
3682 embedded PowerPC processors to implement in hardware simple watchpoint
3683 conditions of the form:
3685 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3687 This works in native GDB running on Linux kernels with the extended ptrace
3688 interface mentioned above.
3690 *** Changes in GDB 7.1
3694 ** Namespace Support
3696 GDB now supports importing of namespaces in C++. This enables the
3697 user to inspect variables from imported namespaces. Support for
3698 namepace aliasing has also been added. So, if a namespace is
3699 aliased in the current scope (e.g. namepace C=A; ) the user can
3700 print variables using the alias (e.g. (gdb) print C::x).
3704 All known bugs relating to the printing of virtual base class were
3705 fixed. It is now possible to call overloaded static methods using a
3710 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3711 and reinterpret_cast<> are now handled by the C++ expression parser.
3715 Xilinx MicroBlaze microblaze-*-*
3720 Xilinx MicroBlaze microblaze
3723 * Multi-program debugging.
3725 GDB now has support for multi-program (a.k.a. multi-executable or
3726 multi-exec) debugging. This allows for debugging multiple inferiors
3727 simultaneously each running a different program under the same GDB
3728 session. See "Debugging Multiple Inferiors and Programs" in the
3729 manual for more information. This implied some user visible changes
3730 in the multi-inferior support. For example, "info inferiors" now
3731 lists inferiors that are not running yet or that have exited
3732 already. See also "New commands" and "New options" below.
3734 * New tracing features
3736 GDB's tracepoint facility now includes several new features:
3738 ** Trace state variables
3740 GDB tracepoints now include support for trace state variables, which
3741 are variables managed by the target agent during a tracing
3742 experiment. They are useful for tracepoints that trigger each
3743 other, so for instance one tracepoint can count hits in a variable,
3744 and then a second tracepoint has a condition that is true when the
3745 count reaches a particular value. Trace state variables share the
3746 $-syntax of GDB convenience variables, and can appear in both
3747 tracepoint actions and condition expressions. Use the "tvariable"
3748 command to create, and "info tvariables" to view; see "Trace State
3749 Variables" in the manual for more detail.
3753 GDB now includes an option for defining fast tracepoints, which
3754 targets may implement more efficiently, such as by installing a jump
3755 into the target agent rather than a trap instruction. The resulting
3756 speedup can be by two orders of magnitude or more, although the
3757 tradeoff is that some program locations on some target architectures
3758 might not allow fast tracepoint installation, for instance if the
3759 instruction to be replaced is shorter than the jump. To request a
3760 fast tracepoint, use the "ftrace" command, with syntax identical to
3761 the regular trace command.
3763 ** Disconnected tracing
3765 It is now possible to detach GDB from the target while it is running
3766 a trace experiment, then reconnect later to see how the experiment
3767 is going. In addition, a new variable disconnected-tracing lets you
3768 tell the target agent whether to continue running a trace if the
3769 connection is lost unexpectedly.
3773 GDB now has the ability to save the trace buffer into a file, and
3774 then use that file as a target, similarly to you can do with
3775 corefiles. You can select trace frames, print data that was
3776 collected in them, and use tstatus to display the state of the
3777 tracing run at the moment that it was saved. To create a trace
3778 file, use "tsave <filename>", and to use it, do "target tfile
3781 ** Circular trace buffer
3783 You can ask the target agent to handle the trace buffer as a
3784 circular buffer, discarding the oldest trace frames to make room for
3785 newer ones, by setting circular-trace-buffer to on. This feature may
3786 not be available for all target agents.
3791 The disassemble command, when invoked with two arguments, now requires
3792 the arguments to be comma-separated.
3795 The info variables command now displays variable definitions. Files
3796 which only declare a variable are not shown.
3799 The source command is now capable of sourcing Python scripts.
3800 This feature is dependent on the debugger being build with Python
3803 Related to this enhancement is also the introduction of a new command
3804 "set script-extension" (see below).
3806 * New commands (for set/show, see "New options" below)
3808 record save [<FILENAME>]
3809 Save a file (in core file format) containing the process record
3810 execution log for replay debugging at a later time.
3812 record restore <FILENAME>
3813 Restore the process record execution log that was saved at an
3814 earlier time, for replay debugging.
3816 add-inferior [-copies <N>] [-exec <FILENAME>]
3819 clone-inferior [-copies <N>] [ID]
3820 Make a new inferior ready to execute the same program another
3821 inferior has loaded.
3826 maint info program-spaces
3827 List the program spaces loaded into GDB.
3829 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3830 show remote interrupt-sequence
3831 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3832 as the sequence to the remote target in order to interrupt the execution.
3833 Ctrl-C is a default. Some system prefers BREAK which is high level of
3834 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3835 Magic SysRq g. It is BREAK signal and character 'g'.
3837 set remote interrupt-on-connect [on | off]
3838 show remote interrupt-on-connect
3839 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3840 remote target when gdb connects to it. This is needed when you debug
3843 set remotebreak [on | off]
3845 Deprecated. Use "set/show remote interrupt-sequence" instead.
3847 tvariable $NAME [ = EXP ]
3848 Create or modify a trace state variable.
3851 List trace state variables and their values.
3853 delete tvariable $NAME ...
3854 Delete one or more trace state variables.
3857 Evaluate the given expressions without collecting anything into the
3858 trace buffer. (Valid in tracepoint actions only.)
3860 ftrace FN / FILE:LINE / *ADDR
3861 Define a fast tracepoint at the given function, line, or address.
3863 * New expression syntax
3865 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3866 GDB now parses 0b101010 identically with 42.
3870 set follow-exec-mode new|same
3871 show follow-exec-mode
3872 Control whether GDB reuses the same inferior across an exec call or
3873 creates a new one. This is useful to be able to restart the old
3874 executable after the inferior having done an exec call.
3876 set default-collect EXPR, ...
3877 show default-collect
3878 Define a list of expressions to be collected at each tracepoint.
3879 This is a useful way to ensure essential items are not overlooked,
3880 such as registers or a critical global variable.
3882 set disconnected-tracing
3883 show disconnected-tracing
3884 If set to 1, the target is instructed to continue tracing if it
3885 loses its connection to GDB. If 0, the target is to stop tracing
3888 set circular-trace-buffer
3889 show circular-trace-buffer
3890 If set to on, the target is instructed to use a circular trace buffer
3891 and discard the oldest trace frames instead of stopping the trace due
3892 to a full trace buffer. If set to off, the trace stops when the buffer
3893 fills up. Some targets may not support this.
3895 set script-extension off|soft|strict
3896 show script-extension
3897 If set to "off", the debugger does not perform any script language
3898 recognition, and all sourced files are assumed to be GDB scripts.
3899 If set to "soft" (the default), files are sourced according to
3900 filename extension, falling back to GDB scripts if the first
3902 If set to "strict", files are sourced according to filename extension.
3904 set ada trust-PAD-over-XVS on|off
3905 show ada trust-PAD-over-XVS
3906 If off, activate a workaround against a bug in the debugging information
3907 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3908 the GCC sources for more information about the GNAT encoding and
3909 PAD types in particular). It is always safe to set this option to
3910 off, but this introduces a slight performance penalty. The default
3913 * Python API Improvements
3915 ** GDB provides the new class gdb.LazyString. This is useful in
3916 some pretty-printing cases. The new method gdb.Value.lazy_string
3917 provides a simple way to create objects of this type.
3919 ** The fields returned by gdb.Type.fields now have an
3920 `is_base_class' attribute.
3922 ** The new method gdb.Type.range returns the range of an array type.
3924 ** The new method gdb.parse_and_eval can be used to parse and
3925 evaluate an expression.
3927 * New remote packets
3930 Define a trace state variable.
3933 Get the current value of a trace state variable.
3936 Set desired tracing behavior upon disconnection.
3939 Set the trace buffer to be linear or circular.
3942 Get data about the tracepoints currently in use.
3946 Process record now works correctly with hardware watchpoints.
3948 Multiple bug fixes have been made to the mips-irix port, making it
3949 much more reliable. In particular:
3950 - Debugging threaded applications is now possible again. Previously,
3951 GDB would hang while starting the program, or while waiting for
3952 the program to stop at a breakpoint.
3953 - Attaching to a running process no longer hangs.
3954 - An error occurring while loading a core file has been fixed.
3955 - Changing the value of the PC register now works again. This fixes
3956 problems observed when using the "jump" command, or when calling
3957 a function from GDB, or even when assigning a new value to $pc.
3958 - With the "finish" and "return" commands, the return value for functions
3959 returning a small array is now correctly printed.
3960 - It is now possible to break on shared library code which gets executed
3961 during a shared library init phase (code executed while executing
3962 their .init section). Previously, the breakpoint would have no effect.
3963 - GDB is now able to backtrace through the signal handler for
3964 non-threaded programs.
3966 PIE (Position Independent Executable) programs debugging is now supported.
3967 This includes debugging execution of PIC (Position Independent Code) shared
3968 libraries although for that, it should be possible to run such libraries as an
3971 *** Changes in GDB 7.0
3973 * GDB now has an interface for JIT compilation. Applications that
3974 dynamically generate code can create symbol files in memory and register
3975 them with GDB. For users, the feature should work transparently, and
3976 for JIT developers, the interface is documented in the GDB manual in the
3977 "JIT Compilation Interface" chapter.
3979 * Tracepoints may now be conditional. The syntax is as for
3980 breakpoints; either an "if" clause appended to the "trace" command,
3981 or the "condition" command is available. GDB sends the condition to
3982 the target for evaluation using the same bytecode format as is used
3983 for tracepoint actions.
3985 * The disassemble command now supports: an optional /r modifier, print the
3986 raw instructions in hex as well as in symbolic form, and an optional /m
3987 modifier to print mixed source+assembly.
3989 * Process record and replay
3991 In a architecture environment that supports ``process record and
3992 replay'', ``process record and replay'' target can record a log of
3993 the process execution, and replay it with both forward and reverse
3996 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3997 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3998 set execution-direction {forward|reverse}, for targets that support
4001 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4002 feature is available with a native GDB running on kernel version
4005 * GDB now has support for multi-byte and wide character sets on the
4006 target. Strings whose character type is wchar_t, char16_t, or
4007 char32_t are now correctly printed. GDB supports wide- and unicode-
4008 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4009 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4010 `printf'. This feature requires iconv to work properly; if your
4011 system does not have a working iconv, GDB can use GNU libiconv. See
4012 the installation instructions for more information.
4014 * GDB now supports automatic retrieval of shared library files from
4015 remote targets. To use this feature, specify a system root that begins
4016 with the `remote:' prefix, either via the `set sysroot' command or via
4017 the `--with-sysroot' configure-time option.
4019 * "info sharedlibrary" now takes an optional regex of libraries to show,
4020 and it now reports if a shared library has no debugging information.
4022 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4023 now complete on file names.
4025 * When completing in expressions, gdb will attempt to limit
4026 completions to allowable structure or union fields, where appropriate.
4027 For instance, consider:
4029 # struct example { int f1; double f2; };
4030 # struct example variable;
4033 If the user types TAB at the end of this command line, the available
4034 completions will be "f1" and "f2".
4036 * Inlined functions are now supported. They show up in backtraces, and
4037 the "step", "next", and "finish" commands handle them automatically.
4039 * GDB now supports the token-splicing (##) and stringification (#)
4040 operators when expanding macros. It also supports variable-arity
4043 * GDB now supports inspecting extra signal information, exported by
4044 the new $_siginfo convenience variable. The feature is currently
4045 implemented on linux ARM, i386 and amd64.
4047 * GDB can now display the VFP floating point registers and NEON vector
4048 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4049 can provide these registers (requires Linux 2.6.30 or later). Remote
4050 and simulator targets may also provide them.
4052 * New remote packets
4055 Search memory for a sequence of bytes.
4058 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4059 operation over reliable transport links. Use of this packet is
4060 controlled by the `set remote noack-packet' command.
4063 Kill the process with the specified process ID. Use this in preference
4064 to `k' when multiprocess protocol extensions are supported.
4067 Obtains additional operating system information
4071 Read or write additional signal information.
4073 * Removed remote protocol undocumented extension
4075 An undocumented extension to the remote protocol's `S' stop reply
4076 packet that permited the stub to pass a process id was removed.
4077 Remote servers should use the `T' stop reply packet instead.
4079 * GDB now supports multiple function calling conventions according to the
4080 DWARF-2 DW_AT_calling_convention function attribute.
4082 * The SH target utilizes the aforementioned change to distinguish between gcc
4083 and Renesas calling convention. It also adds the new CLI commands
4084 `set/show sh calling-convention'.
4086 * GDB can now read compressed debug sections, as produced by GNU gold
4087 with the --compress-debug-sections=zlib flag.
4089 * 64-bit core files are now supported on AIX.
4091 * Thread switching is now supported on Tru64.
4093 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4094 which will be allocated using malloc later in program execution.
4096 * The qXfer:libraries:read remote procotol packet now allows passing a
4097 list of section offsets.
4099 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4100 conditions handling signals delivered during attach or thread creation
4101 have also been fixed.
4103 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4104 From the user's standpoint, all unqualified instances of True and False
4105 are treated as the standard definitions, regardless of context.
4107 * GDB now parses C++ symbol and type names more flexibly. For
4110 template<typename T> class C { };
4113 GDB will now correctly handle all of:
4115 ptype C<char const *>
4116 ptype C<char const*>
4117 ptype C<const char *>
4118 ptype C<const char*>
4120 * New features in the GDB remote stub, gdbserver
4122 - The "--wrapper" command-line argument tells gdbserver to use a
4123 wrapper program to launch programs for debugging.
4125 - On PowerPC and S/390 targets, it is now possible to use a single
4126 gdbserver executable to debug both 32-bit and 64-bit programs.
4127 (This requires gdbserver itself to be built as a 64-bit executable.)
4129 - gdbserver uses the new noack protocol mode for TCP connections to
4130 reduce communications latency, if also supported and enabled in GDB.
4132 - Support for the sparc64-linux-gnu target is now included in
4135 - The amd64-linux build of gdbserver now supports debugging both
4136 32-bit and 64-bit programs.
4138 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4139 now support hardware watchpoints, and will use them automatically
4144 GDB now has support for scripting using Python. Whether this is
4145 available is determined at configure time.
4147 New GDB commands can now be written in Python.
4149 * Ada tasking support
4151 Ada tasks can now be inspected in GDB. The following commands have
4155 Print the list of Ada tasks.
4157 Print detailed information about task number N.
4159 Print the task number of the current task.
4161 Switch the context of debugging to task number N.
4163 * Support for user-defined prefixed commands. The "define" command can
4164 add new commands to existing prefixes, e.g. "target".
4166 * Multi-inferior, multi-process debugging.
4168 GDB now has generalized support for multi-inferior debugging. See
4169 "Debugging Multiple Inferiors" in the manual for more information.
4170 Although availability still depends on target support, the command
4171 set is more uniform now. The GNU/Linux specific multi-forks support
4172 has been migrated to this new framework. This implied some user
4173 visible changes; see "New commands" and also "Removed commands"
4176 * Target descriptions can now describe the target OS ABI. See the
4177 "Target Description Format" section in the user manual for more
4180 * Target descriptions can now describe "compatible" architectures
4181 to indicate that the target can execute applications for a different
4182 architecture in addition to those for the main target architecture.
4183 See the "Target Description Format" section in the user manual for
4186 * Multi-architecture debugging.
4188 GDB now includes general supports for debugging applications on
4189 hybrid systems that use more than one single processor architecture
4190 at the same time. Each such hybrid architecture still requires
4191 specific support to be added. The only hybrid architecture supported
4192 in this version of GDB is the Cell Broadband Engine.
4194 * GDB now supports integrated debugging of Cell/B.E. applications that
4195 use both the PPU and SPU architectures. To enable support for hybrid
4196 Cell/B.E. debugging, you need to configure GDB to support both the
4197 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4198 --enable-targets configure option.
4200 * Non-stop mode debugging.
4202 For some targets, GDB now supports an optional mode of operation in
4203 which you can examine stopped threads while other threads continue
4204 to execute freely. This is referred to as non-stop mode, with the
4205 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4206 section in the user manual for more information.
4208 To be able to support remote non-stop debugging, a remote stub needs
4209 to implement the non-stop mode remote protocol extensions, as
4210 described in the "Remote Non-Stop" section of the user manual. The
4211 GDB remote stub, gdbserver, has been adjusted to support these
4212 extensions on linux targets.
4214 * New commands (for set/show, see "New options" below)
4216 catch syscall [NAME(S) | NUMBER(S)]
4217 Catch system calls. Arguments, which should be names of system
4218 calls or their numbers, mean catch only those syscalls. Without
4219 arguments, every syscall will be caught. When the inferior issues
4220 any of the specified syscalls, GDB will stop and announce the system
4221 call, both when it is called and when its call returns. This
4222 feature is currently available with a native GDB running on the
4223 Linux Kernel, under the following architectures: x86, x86_64,
4224 PowerPC and PowerPC64.
4226 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4228 Search memory for a sequence of bytes.
4230 maint set python print-stack
4231 maint show python print-stack
4232 Show a stack trace when an error is encountered in a Python script.
4235 Invoke CODE by passing it to the Python interpreter.
4240 These allow macros to be defined, undefined, and listed
4244 Show operating system information about processes.
4247 List the inferiors currently under GDB's control.
4250 Switch focus to inferior number NUM.
4253 Detach from inferior number NUM.
4256 Kill inferior number NUM.
4260 set spu stop-on-load
4261 show spu stop-on-load
4262 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4264 set spu auto-flush-cache
4265 show spu auto-flush-cache
4266 Control whether to automatically flush the software-managed cache
4267 during Cell/B.E. debugging.
4269 set sh calling-convention
4270 show sh calling-convention
4271 Control the calling convention used when calling SH target functions.
4274 show debug timestamp
4275 Control display of timestamps with GDB debugging output.
4277 set disassemble-next-line
4278 show disassemble-next-line
4279 Control display of disassembled source lines or instructions when
4282 set remote noack-packet
4283 show remote noack-packet
4284 Set/show the use of remote protocol QStartNoAckMode packet. See above
4285 under "New remote packets."
4287 set remote query-attached-packet
4288 show remote query-attached-packet
4289 Control use of remote protocol `qAttached' (query-attached) packet.
4291 set remote read-siginfo-object
4292 show remote read-siginfo-object
4293 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4296 set remote write-siginfo-object
4297 show remote write-siginfo-object
4298 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4301 set remote reverse-continue
4302 show remote reverse-continue
4303 Control use of remote protocol 'bc' (reverse-continue) packet.
4305 set remote reverse-step
4306 show remote reverse-step
4307 Control use of remote protocol 'bs' (reverse-step) packet.
4309 set displaced-stepping
4310 show displaced-stepping
4311 Control displaced stepping mode. Displaced stepping is a way to
4312 single-step over breakpoints without removing them from the debuggee.
4313 Also known as "out-of-line single-stepping".
4316 show debug displaced
4317 Control display of debugging info for displaced stepping.
4319 maint set internal-error
4320 maint show internal-error
4321 Control what GDB does when an internal error is detected.
4323 maint set internal-warning
4324 maint show internal-warning
4325 Control what GDB does when an internal warning is detected.
4330 Use a wrapper program to launch programs for debugging.
4332 set multiple-symbols (all|ask|cancel)
4333 show multiple-symbols
4334 The value of this variable can be changed to adjust the debugger behavior
4335 when an expression or a breakpoint location contains an ambiguous symbol
4336 name (an overloaded function name, for instance).
4338 set breakpoint always-inserted
4339 show breakpoint always-inserted
4340 Keep breakpoints always inserted in the target, as opposed to inserting
4341 them when resuming the target, and removing them when the target stops.
4342 This option can improve debugger performance on slow remote targets.
4344 set arm fallback-mode (arm|thumb|auto)
4345 show arm fallback-mode
4346 set arm force-mode (arm|thumb|auto)
4348 These commands control how ARM GDB determines whether instructions
4349 are ARM or Thumb. The default for both settings is auto, which uses
4350 the current CPSR value for instructions without symbols; previous
4351 versions of GDB behaved as if "set arm fallback-mode arm".
4353 set disable-randomization
4354 show disable-randomization
4355 Standalone programs run with the virtual address space randomization enabled
4356 by default on some platforms. This option keeps the addresses stable across
4357 multiple debugging sessions.
4361 Control whether other threads are stopped or not when some thread hits
4366 Requests that asynchronous execution is enabled in the target, if available.
4367 In this case, it's possible to resume target in the background, and interact
4368 with GDB while the target is running. "show target-async" displays the
4369 current state of asynchronous execution of the target.
4371 set target-wide-charset
4372 show target-wide-charset
4373 The target-wide-charset is the name of the character set that GDB
4374 uses when printing characters whose type is wchar_t.
4376 set tcp auto-retry (on|off)
4378 set tcp connect-timeout
4379 show tcp connect-timeout
4380 These commands allow GDB to retry failed TCP connections to a remote stub
4381 with a specified timeout period; this is useful if the stub is launched
4382 in parallel with GDB but may not be ready to accept connections immediately.
4384 set libthread-db-search-path
4385 show libthread-db-search-path
4386 Control list of directories which GDB will search for appropriate
4389 set schedule-multiple (on|off)
4390 show schedule-multiple
4391 Allow GDB to resume all threads of all processes or only threads of
4392 the current process.
4396 Use more aggressive caching for accesses to the stack. This improves
4397 performance of remote debugging (particularly backtraces) without
4398 affecting correctness.
4400 set interactive-mode (on|off|auto)
4401 show interactive-mode
4402 Control whether GDB runs in interactive mode (on) or not (off).
4403 When in interactive mode, GDB waits for the user to answer all
4404 queries. Otherwise, GDB does not wait and assumes the default
4405 answer. When set to auto (the default), GDB determines which
4406 mode to use based on the stdin settings.
4411 For program forks, this is replaced by the new more generic `info
4412 inferiors' command. To list checkpoints, you can still use the
4413 `info checkpoints' command, which was an alias for the `info forks'
4417 Replaced by the new `inferior' command. To switch between
4418 checkpoints, you can still use the `restart' command, which was an
4419 alias for the `fork' command.
4422 This is removed, since some targets don't have a notion of
4423 processes. To switch between processes, you can still use the
4424 `inferior' command using GDB's own inferior number.
4427 For program forks, this is replaced by the new more generic `kill
4428 inferior' command. To delete a checkpoint, you can still use the
4429 `delete checkpoint' command, which was an alias for the `delete
4433 For program forks, this is replaced by the new more generic `detach
4434 inferior' command. To detach a checkpoint, you can still use the
4435 `detach checkpoint' command, which was an alias for the `detach
4438 * New native configurations
4440 x86/x86_64 Darwin i[34567]86-*-darwin*
4442 x86_64 MinGW x86_64-*-mingw*
4446 Lattice Mico32 lm32-*
4447 x86 DICOS i[34567]86-*-dicos*
4448 x86_64 DICOS x86_64-*-dicos*
4451 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4452 (mingw32ce) debugging.
4458 These commands were actually not implemented on any target.
4460 *** Changes in GDB 6.8
4462 * New native configurations
4464 NetBSD/hppa hppa*-*netbsd*
4465 Xtensa GNU/Linux xtensa*-*-linux*
4469 NetBSD/hppa hppa*-*-netbsd*
4470 Xtensa GNU/Lunux xtensa*-*-linux*
4472 * Change in command line behavior -- corefiles vs. process ids.
4474 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4475 attaching to process NUMBER fails, GDB no longer attempts to open a
4476 core file named NUMBER. Attaching to a program using the -c option
4477 is no longer supported. Instead, use the '-p' or '--pid' options.
4479 * GDB can now be built as a native debugger for debugging Windows x86
4480 (mingw32) Portable Executable (PE) programs.
4482 * Pending breakpoints no longer change their number when their address
4485 * GDB now supports breakpoints with multiple locations,
4486 including breakpoints on C++ constructors, inside C++ templates,
4487 and in inlined functions.
4489 * GDB's ability to debug optimized code has been improved. GDB more
4490 accurately identifies function bodies and lexical blocks that occupy
4491 more than one contiguous range of addresses.
4493 * Target descriptions can now describe registers for PowerPC.
4495 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4496 registers on PowerPC targets.
4498 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4499 targets even when the libthread_db library is not available.
4501 * The GDB remote stub, gdbserver, now supports the new file transfer
4502 commands (remote put, remote get, and remote delete).
4504 * The GDB remote stub, gdbserver, now supports run and attach in
4505 extended-remote mode.
4507 * hppa*64*-*-hpux11* target broken
4508 The debugger is unable to start a program and fails with the following
4509 error: "Error trying to get information about dynamic linker".
4510 The gdb-6.7 release is also affected.
4512 * GDB now supports the --enable-targets= configure option to allow
4513 building a single GDB executable that supports multiple remote
4514 target architectures.
4516 * GDB now supports debugging C and C++ programs which use the
4517 Decimal Floating Point extension. In addition, the PowerPC target
4518 now has a set of pseudo-registers to inspect decimal float values
4519 stored in two consecutive float registers.
4521 * The -break-insert MI command can optionally create pending
4524 * Improved support for debugging Ada
4525 Many improvements to the Ada language support have been made. These
4527 - Better support for Ada2005 interface types
4528 - Improved handling of arrays and slices in general
4529 - Better support for Taft-amendment types
4530 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4532 - Improved command completion in Ada
4535 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4540 set print frame-arguments (all|scalars|none)
4541 show print frame-arguments
4542 The value of this variable can be changed to control which argument
4543 values should be printed by the debugger when displaying a frame.
4548 Transfer files to and from a remote target, and delete remote files.
4555 Transfer files to and from a remote target, and delete remote files.
4557 * New remote packets
4564 Open, close, read, write, and delete files on the remote system.
4567 Attach to an existing process on the remote system, in extended-remote
4571 Run a new process on the remote system, in extended-remote mode.
4573 *** Changes in GDB 6.7
4575 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4576 bfd, libiberty and opcodes, as revealed by static analysis donated by
4577 Coverity, Inc. (http://scan.coverity.com).
4579 * When looking up multiply-defined global symbols, GDB will now prefer the
4580 symbol definition in the current shared library if it was built using the
4581 -Bsymbolic linker option.
4583 * When the Text User Interface (TUI) is not configured, GDB will now
4584 recognize the -tui command-line option and print a message that the TUI
4587 * The GDB remote stub, gdbserver, now has lower overhead for high
4588 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4590 * GDB for MIPS targets now autodetects whether a remote target provides
4591 32-bit or 64-bit register values.
4593 * Support for C++ member pointers has been improved.
4595 * GDB now understands XML target descriptions, which specify the
4596 target's overall architecture. GDB can read a description from
4597 a local file or over the remote serial protocol.
4599 * Vectors of single-byte data use a new integer type which is not
4600 automatically displayed as character or string data.
4602 * The /s format now works with the print command. It displays
4603 arrays of single-byte integers and pointers to single-byte integers
4606 * Target descriptions can now describe target-specific registers,
4607 for architectures which have implemented the support (currently
4608 only ARM, M68K, and MIPS).
4610 * GDB and the GDB remote stub, gdbserver, now support the XScale
4613 * The GDB remote stub, gdbserver, has been updated to support
4614 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4615 has been rewritten to use the standard GDB remote protocol.
4617 * GDB can now step into C++ functions which are called through thunks.
4619 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4621 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4622 layout. It also supports a TextSeg= and DataSeg= response when only
4623 segment base addresses (rather than offsets) are available.
4625 * The /i format now outputs any trailing branch delay slot instructions
4626 immediately following the last instruction within the count specified.
4628 * The GDB remote protocol "T" stop reply packet now supports a
4629 "library" response. Combined with the new "qXfer:libraries:read"
4630 packet, this response allows GDB to debug shared libraries on targets
4631 where the operating system manages the list of loaded libraries (e.g.
4632 Windows and SymbianOS).
4634 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4635 (DLLs) on Windows and Windows CE targets.
4637 * GDB now supports a faster verification that a .debug file matches its binary
4638 according to its build-id signature, if the signature is present.
4644 Enable or disable hardware flow control (RTS/CTS) on the serial port
4645 when debugging using remote targets.
4647 set mem inaccessible-by-default
4648 show mem inaccessible-by-default
4649 If the target supplies a memory map, for instance via the remote
4650 protocol's "qXfer:memory-map:read" packet, setting this variable
4651 prevents GDB from accessing memory outside the memory map. This
4652 is useful for targets with memory mapped registers or which react
4653 badly to accesses of unmapped address space.
4655 set breakpoint auto-hw
4656 show breakpoint auto-hw
4657 If the target supplies a memory map, for instance via the remote
4658 protocol's "qXfer:memory-map:read" packet, setting this variable
4659 lets GDB use hardware breakpoints automatically for memory regions
4660 where it can not use software breakpoints. This covers both the
4661 "break" command and internal breakpoints used for other commands
4662 including "next" and "finish".
4665 catch exception unhandled
4666 Stop the program execution when Ada exceptions are raised.
4669 Stop the program execution when an Ada assertion failed.
4673 Set an alternate system root for target files. This is a more
4674 general version of "set solib-absolute-prefix", which is now
4675 an alias to "set sysroot".
4678 Provide extended SPU facility status information. This set of
4679 commands is available only when debugging the Cell/B.E. SPU
4682 * New native configurations
4684 OpenBSD/sh sh*-*openbsd*
4687 unset tdesc filename
4689 Use the specified local file as an XML target description, and do
4690 not query the target for its built-in description.
4694 OpenBSD/sh sh*-*-openbsd*
4695 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4696 Toshiba Media Processor mep-elf
4698 * New remote packets
4701 Ignore the specified signals; pass them directly to the debugged program
4702 without stopping other threads or reporting them to GDB.
4704 qXfer:features:read:
4705 Read an XML target description from the target, which describes its
4710 Read or write contents of an spufs file on the target system. These
4711 packets are available only on the Cell/B.E. SPU architecture.
4713 qXfer:libraries:read:
4714 Report the loaded shared libraries. Combined with new "T" packet
4715 response, this packet allows GDB to debug shared libraries on
4716 targets where the operating system manages the list of loaded
4717 libraries (e.g. Windows and SymbianOS).
4721 Support for these obsolete configurations has been removed.
4729 i[34567]86-*-lynxos*
4730 i[34567]86-*-netware*
4731 i[34567]86-*-sco3.2v5*
4732 i[34567]86-*-sco3.2v4*
4734 i[34567]86-*-sysv4.2*
4737 i[34567]86-*-unixware2*
4738 i[34567]86-*-unixware*
4747 * Other removed features
4754 Various m68k-only ROM monitors.
4761 Various Renesas ROM monitors and debugging interfaces for SH and
4766 Support for a Macraigor serial interface to on-chip debugging.
4767 GDB does not directly support the newer parallel or USB
4772 A debug information format. The predecessor to DWARF 2 and
4773 DWARF 3, which are still supported.
4775 Support for the HP aCC compiler on HP-UX/PA-RISC
4777 SOM-encapsulated symbolic debugging information, automatic
4778 invocation of pxdb, and the aCC custom C++ ABI. This does not
4779 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4780 with aCC can still be debugged on an assembly level.
4782 MIPS ".pdr" sections
4784 A MIPS-specific format used to describe stack frame layout
4785 in debugging information.
4789 GDB could work with an older version of Guile to debug
4790 the interpreter and Scheme programs running in it.
4792 set mips stack-arg-size
4793 set mips saved-gpreg-size
4795 Use "set mips abi" to control parameter passing for MIPS.
4797 *** Changes in GDB 6.6
4802 Cell Broadband Engine SPU spu-elf
4804 * GDB can now be configured as a cross-debugger targeting native Windows
4805 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4806 running on a Windows system over TCP/IP to debug Windows programs.
4808 * The GDB remote stub, gdbserver, has been updated to support Windows and
4809 Cygwin debugging. Both single-threaded and multi-threaded programs are
4812 * The "set trust-readonly-sections" command works again. This command was
4813 broken in GDB 6.3, 6.4, and 6.5.
4815 * The "load" command now supports writing to flash memory, if the remote
4816 stub provides the required support.
4818 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4819 longer requires symbolic debug information (e.g. DWARF-2).
4824 unset substitute-path
4825 show substitute-path
4826 Manage a list of substitution rules that GDB uses to rewrite the name
4827 of the directories where the sources are located. This can be useful
4828 for instance when the sources were moved to a different location
4829 between compilation and debugging.
4833 Print each CLI command as it is executed. Each command is prefixed with
4834 a number of `+' symbols representing the nesting depth.
4835 The source command now has a `-v' option to enable the same feature.
4839 The ARM Demon monitor support (RDP protocol, "target rdp").
4841 Kernel Object Display, an embedded debugging feature which only worked with
4842 an obsolete version of Cisco IOS.
4844 The 'set download-write-size' and 'show download-write-size' commands.
4846 * New remote packets
4849 Tell a stub about GDB client features, and request remote target features.
4850 The first feature implemented is PacketSize, which allows the target to
4851 specify the size of packets it can handle - to minimize the number of
4852 packets required and improve performance when connected to a remote
4856 Fetch an OS auxilliary vector from the remote stub. This packet is a
4857 more efficient replacement for qPart:auxv:read.
4859 qXfer:memory-map:read:
4860 Fetch a memory map from the remote stub, including information about
4861 RAM, ROM, and flash memory devices.
4866 Erase and program a flash memory device.
4868 * Removed remote packets
4871 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4872 used it, and only gdbserver implemented it.
4874 *** Changes in GDB 6.5
4878 Renesas M32C/M16C m32c-elf
4880 Morpho Technologies ms1 ms1-elf
4884 init-if-undefined Initialize a convenience variable, but
4885 only if it doesn't already have a value.
4887 The following commands are presently only implemented for native GNU/Linux:
4889 checkpoint Save a snapshot of the program state.
4891 restart <n> Return the program state to a
4892 previously saved state.
4894 info checkpoints List currently saved checkpoints.
4896 delete-checkpoint <n> Delete a previously saved checkpoint.
4898 set|show detach-on-fork Tell gdb whether to detach from a newly
4899 forked process, or to keep debugging it.
4901 info forks List forks of the user program that
4902 are available to be debugged.
4904 fork <n> Switch to debugging one of several
4905 forks of the user program that are
4906 available to be debugged.
4908 delete-fork <n> Delete a fork from the list of forks
4909 that are available to be debugged (and
4910 kill the forked process).
4912 detach-fork <n> Delete a fork from the list of forks
4913 that are available to be debugged (and
4914 allow the process to continue).
4918 Morpho Technologies ms2 ms1-elf
4920 * Improved Windows host support
4922 GDB now builds as a cross debugger hosted on i686-mingw32, including
4923 native console support, and remote communications using either
4924 network sockets or serial ports.
4926 * Improved Modula-2 language support
4928 GDB can now print most types in the Modula-2 syntax. This includes:
4929 basic types, set types, record types, enumerated types, range types,
4930 pointer types and ARRAY types. Procedure var parameters are correctly
4931 printed and hexadecimal addresses and character constants are also
4932 written in the Modula-2 syntax. Best results can be obtained by using
4933 GNU Modula-2 together with the -gdwarf-2 command line option.
4937 The ARM rdi-share module.
4939 The Netware NLM debug server.
4941 *** Changes in GDB 6.4
4943 * New native configurations
4945 OpenBSD/arm arm*-*-openbsd*
4946 OpenBSD/mips64 mips64-*-openbsd*
4950 Morpho Technologies ms1 ms1-elf
4952 * New command line options
4954 --batch-silent As for --batch, but totally silent.
4955 --return-child-result The debugger will exist with the same value
4956 the child (debugged) program exited with.
4957 --eval-command COMMAND, -ex COMMAND
4958 Execute a single GDB CLI command. This may be
4959 specified multiple times and in conjunction
4960 with the --command (-x) option.
4962 * Deprecated commands removed
4964 The following commands, that were deprecated in 2000, have been
4968 set|show arm disassembly-flavor set|show arm disassembler
4969 othernames set arm disassembler
4970 set|show remotedebug set|show debug remote
4971 set|show archdebug set|show debug arch
4972 set|show eventdebug set|show debug event
4975 * New BSD user-level threads support
4977 It is now possible to debug programs using the user-level threads
4978 library on OpenBSD and FreeBSD. Currently supported (target)
4981 FreeBSD/amd64 x86_64-*-freebsd*
4982 FreeBSD/i386 i386-*-freebsd*
4983 OpenBSD/i386 i386-*-openbsd*
4985 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4986 are not yet supported.
4988 * New support for Matsushita MN10300 w/sim added
4989 (Work in progress). mn10300-elf.
4991 * REMOVED configurations and files
4993 VxWorks and the XDR protocol *-*-vxworks
4994 Motorola MCORE mcore-*-*
4995 National Semiconductor NS32000 ns32k-*-*
4997 * New "set print array-indexes" command
4999 After turning this setting "on", GDB prints the index of each element
5000 when displaying arrays. The default is "off" to preserve the previous
5003 * VAX floating point support
5005 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5007 * User-defined command support
5009 In addition to using $arg0..$arg9 for argument passing, it is now possible
5010 to use $argc to determine now many arguments have been passed. See the
5011 section on user-defined commands in the user manual for more information.
5013 *** Changes in GDB 6.3:
5015 * New command line option
5017 GDB now accepts -l followed by a number to set the timeout for remote
5020 * GDB works with GCC -feliminate-dwarf2-dups
5022 GDB now supports a more compact representation of DWARF-2 debug
5023 information using DW_FORM_ref_addr references. These are produced
5024 by GCC with the option -feliminate-dwarf2-dups and also by some
5025 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5026 to use -feliminate-dwarf2-dups.
5028 * Internationalization
5030 When supported by the host system, GDB will be built with
5031 internationalization (libintl). The task of marking up the sources is
5032 continued, we're looking forward to our first translation.
5036 Initial support for debugging programs compiled with the GNAT
5037 implementation of the Ada programming language has been integrated
5038 into GDB. In this release, support is limited to expression evaluation.
5040 * New native configurations
5042 GNU/Linux/m32r m32r-*-linux-gnu
5046 GDB's remote protocol now includes support for the 'p' packet. This
5047 packet is used to fetch individual registers from a remote inferior.
5049 * END-OF-LIFE registers[] compatibility module
5051 GDB's internal register infrastructure has been completely rewritten.
5052 The new infrastructure making possible the implementation of key new
5053 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5056 GDB 6.3 will be the last release to include the the registers[]
5057 compatibility module that allowed out-of-date configurations to
5058 continue to work. This change directly impacts the following
5068 powerpc bdm protocol
5070 Unless there is activity to revive these configurations, they will be
5071 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5073 * OBSOLETE configurations and files
5075 Configurations that have been declared obsolete in this release have
5076 been commented out. Unless there is activity to revive these
5077 configurations, the next release of GDB will have their sources
5078 permanently REMOVED.
5087 *** Changes in GDB 6.2.1:
5089 * MIPS `break main; run' gave an heuristic-fence-post warning
5091 When attempting to run even a simple program, a warning about
5092 heuristic-fence-post being hit would be reported. This problem has
5095 * MIPS IRIX 'long double' crashed GDB
5097 When examining a long double variable, GDB would get a segmentation
5098 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5099 IRIX long double values).
5103 A bug in the VAX stack code was causing problems with the "next"
5104 command. This problem has been fixed.
5106 *** Changes in GDB 6.2:
5108 * Fix for ``many threads''
5110 On GNU/Linux systems that use the NPTL threads library, a program
5111 rapidly creating and deleting threads would confuse GDB leading to the
5114 ptrace: No such process.
5115 thread_db_get_info: cannot get thread info: generic error
5117 This problem has been fixed.
5119 * "-async" and "-noasync" options removed.
5121 Support for the broken "-noasync" option has been removed (it caused
5124 * New ``start'' command.
5126 This command runs the program until the begining of the main procedure.
5128 * New BSD Kernel Data Access Library (libkvm) interface
5130 Using ``target kvm'' it is now possible to debug kernel core dumps and
5131 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5132 platforms. Currently supported (native-only) configurations are:
5134 FreeBSD/amd64 x86_64-*-freebsd*
5135 FreeBSD/i386 i?86-*-freebsd*
5136 NetBSD/i386 i?86-*-netbsd*
5137 NetBSD/m68k m68*-*-netbsd*
5138 NetBSD/sparc sparc-*-netbsd*
5139 OpenBSD/amd64 x86_64-*-openbsd*
5140 OpenBSD/i386 i?86-*-openbsd*
5141 OpenBSD/m68k m68*-openbsd*
5142 OpenBSD/sparc sparc-*-openbsd*
5144 * Signal trampoline code overhauled
5146 Many generic problems with GDB's signal handling code have been fixed.
5147 These include: backtraces through non-contiguous stacks; recognition
5148 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5149 call; backtrace through a signal trampoline; step into and out of
5150 signal handlers; and single-stepping in the signal trampoline.
5152 Please note that kernel bugs are a limiting factor here. These
5153 features have been shown to work on an s390 GNU/Linux system that
5154 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5156 * Cygwin support for DWARF 2 added.
5158 * New native configurations
5160 GNU/Linux/hppa hppa*-*-linux*
5161 OpenBSD/hppa hppa*-*-openbsd*
5162 OpenBSD/m68k m68*-*-openbsd*
5163 OpenBSD/m88k m88*-*-openbsd*
5164 OpenBSD/powerpc powerpc-*-openbsd*
5165 NetBSD/vax vax-*-netbsd*
5166 OpenBSD/vax vax-*-openbsd*
5168 * END-OF-LIFE frame compatibility module
5170 GDB's internal frame infrastructure has been completely rewritten.
5171 The new infrastructure making it possible to support key new features
5172 including DWARF 2 Call Frame Information. To aid in the task of
5173 migrating old configurations to this new infrastructure, a
5174 compatibility module, that allowed old configurations to continue to
5175 work, was also included.
5177 GDB 6.2 will be the last release to include this frame compatibility
5178 module. This change directly impacts the following configurations:
5188 Unless there is activity to revive these configurations, they will be
5189 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5191 * REMOVED configurations and files
5193 Sun 3, running SunOS 3 m68*-*-sunos3*
5194 Sun 3, running SunOS 4 m68*-*-sunos4*
5195 Sun 2, running SunOS 3 m68000-*-sunos3*
5196 Sun 2, running SunOS 4 m68000-*-sunos4*
5197 Motorola 680x0 running LynxOS m68*-*-lynxos*
5198 AT&T 3b1/Unix pc m68*-att-*
5199 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5200 decstation mips-dec-* mips-little-*
5201 riscos mips-*-riscos* mips-*-sysv*
5202 sonymips mips-sony-*
5203 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5205 *** Changes in GDB 6.1.1:
5207 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5209 The TUI (Text-mode User Interface) is now built as part of a default
5210 GDB configuration. It is enabled by either selecting the TUI with the
5211 command line option "-i=tui" or by running the separate "gdbtui"
5212 program. For more information on the TUI, see the manual "Debugging
5215 * Pending breakpoint support (also included in GDB 6.1)
5217 Support has been added to allow you to specify breakpoints in shared
5218 libraries that have not yet been loaded. If a breakpoint location
5219 cannot be found, and the "breakpoint pending" option is set to auto,
5220 GDB queries you if you wish to make the breakpoint pending on a future
5221 shared-library load. If and when GDB resolves the breakpoint symbol,
5222 the pending breakpoint is removed as one or more regular breakpoints
5225 Pending breakpoints are very useful for GCJ Java debugging.
5227 * Fixed ISO-C build problems
5229 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5230 non ISO-C code that stopped them being built using a more strict ISO-C
5231 compiler (e.g., IBM's C compiler).
5233 * Fixed build problem on IRIX 5
5235 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5236 wasn't able to compile compile on an IRIX 5 system.
5238 * Added execute permission to gdb/gdbserver/configure
5240 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5241 permission. This bug would cause configure to fail on a number of
5242 systems (Solaris, IRIX). Ref: server/519.
5244 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5246 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5247 has been updated to use constant array sizes.
5249 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5251 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5252 its generated DWARF Call Frame Info. This encoding was causing GDB to
5253 panic, that panic has been fixed. Ref: gdb/1628.
5255 * Fixed a problem when examining parameters in shared library code.
5257 When examining parameters in optimized shared library code generated
5258 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5259 not available''. GDB now correctly displays the variable's value.
5261 *** Changes in GDB 6.1:
5263 * Removed --with-mmalloc
5265 Support for the mmalloc memory manager has been removed, as it
5266 conflicted with the internal gdb byte cache.
5268 * Changes in AMD64 configurations
5270 The AMD64 target now includes the %cs and %ss registers. As a result
5271 the AMD64 remote protocol has changed; this affects the floating-point
5272 and SSE registers. If you rely on those registers for your debugging,
5273 you should upgrade gdbserver on the remote side.
5275 * Revised SPARC target
5277 The SPARC target has been completely revised, incorporating the
5278 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5279 support for LynxOS and SunOS 4 has been dropped. Calling functions
5280 from within GDB on operating systems with a non-executable stack
5281 (Solaris, OpenBSD) now works.
5285 GDB has a new C++ demangler which does a better job on the mangled
5286 names generated by current versions of g++. It also runs faster, so
5287 with this and other changes gdb should now start faster on large C++
5290 * DWARF 2 Location Expressions
5292 GDB support for location expressions has been extended to support function
5293 arguments and frame bases. Older versions of GDB could crash when they
5296 * C++ nested types and namespaces
5298 GDB's support for nested types and namespaces in C++ has been
5299 improved, especially if you use the DWARF 2 debugging format. (This
5300 is the default for recent versions of GCC on most platforms.)
5301 Specifically, if you have a class "Inner" defined within a class or
5302 namespace "Outer", then GDB realizes that the class's name is
5303 "Outer::Inner", not simply "Inner". This should greatly reduce the
5304 frequency of complaints about not finding RTTI symbols. In addition,
5305 if you are stopped at inside of a function defined within a namespace,
5306 GDB modifies its name lookup accordingly.
5308 * New native configurations
5310 NetBSD/amd64 x86_64-*-netbsd*
5311 OpenBSD/amd64 x86_64-*-openbsd*
5312 OpenBSD/alpha alpha*-*-openbsd*
5313 OpenBSD/sparc sparc-*-openbsd*
5314 OpenBSD/sparc64 sparc64-*-openbsd*
5316 * New debugging protocols
5318 M32R with SDI protocol m32r-*-elf*
5320 * "set prompt-escape-char" command deleted.
5322 The command "set prompt-escape-char" has been deleted. This command,
5323 and its very obscure effet on GDB's prompt, was never documented,
5324 tested, nor mentioned in the NEWS file.
5326 * OBSOLETE configurations and files
5328 Configurations that have been declared obsolete in this release have
5329 been commented out. Unless there is activity to revive these
5330 configurations, the next release of GDB will have their sources
5331 permanently REMOVED.
5333 Sun 3, running SunOS 3 m68*-*-sunos3*
5334 Sun 3, running SunOS 4 m68*-*-sunos4*
5335 Sun 2, running SunOS 3 m68000-*-sunos3*
5336 Sun 2, running SunOS 4 m68000-*-sunos4*
5337 Motorola 680x0 running LynxOS m68*-*-lynxos*
5338 AT&T 3b1/Unix pc m68*-att-*
5339 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5340 decstation mips-dec-* mips-little-*
5341 riscos mips-*-riscos* mips-*-sysv*
5342 sonymips mips-sony-*
5343 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5345 * REMOVED configurations and files
5347 SGI Irix-4.x mips-sgi-irix4 or iris4
5348 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5349 Z8000 simulator z8k-zilog-none or z8ksim
5350 Matsushita MN10200 w/simulator mn10200-*-*
5351 H8/500 simulator h8500-hitachi-hms or h8500hms
5352 HP/PA running BSD hppa*-*-bsd*
5353 HP/PA running OSF/1 hppa*-*-osf*
5354 HP/PA Pro target hppa*-*-pro*
5355 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5356 386BSD i[3456]86-*-bsd*
5357 Sequent family i[3456]86-sequent-sysv4*
5358 i[3456]86-sequent-sysv*
5359 i[3456]86-sequent-bsd*
5360 SPARC running LynxOS sparc-*-lynxos*
5361 SPARC running SunOS 4 sparc-*-sunos4*
5362 Tsqware Sparclet sparclet-*-*
5363 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5365 *** Changes in GDB 6.0:
5369 Support for debugging the Objective-C programming language has been
5370 integrated into GDB.
5372 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5374 DWARF 2's Call Frame Information makes available compiler generated
5375 information that more exactly describes the program's run-time stack.
5376 By using this information, GDB is able to provide more robust stack
5379 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5380 have been updated to use a new backtrace mechanism which includes
5381 DWARF 2 CFI support.
5385 GDB's remote protocol has been extended to include support for hosted
5386 file I/O (where the remote target uses GDB's file system). See GDB's
5387 remote protocol documentation for details.
5389 * All targets using the new architecture framework.
5391 All of GDB's targets have been updated to use the new internal
5392 architecture framework. The way is now open for future GDB releases
5393 to include cross-architecture native debugging support (i386 on amd64,
5396 * GNU/Linux's Thread Local Storage (TLS)
5398 GDB now includes support for for the GNU/Linux implementation of
5399 per-thread variables.
5401 * GNU/Linux's Native POSIX Thread Library (NPTL)
5403 GDB's thread code has been updated to work with either the new
5404 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5406 * Separate debug info.
5408 GDB, in conjunction with BINUTILS, now supports a mechanism for
5409 automatically loading debug information from a separate file. Instead
5410 of shipping full debug and non-debug versions of system libraries,
5411 system integrators can now instead ship just the stripped libraries
5412 and optional debug files.
5414 * DWARF 2 Location Expressions
5416 DWARF 2 Location Expressions allow the compiler to more completely
5417 describe the location of variables (even in optimized code) to the
5420 GDB now includes preliminary support for location expressions (support
5421 for DW_OP_piece is still missing).
5425 A number of long standing bugs that caused GDB to die while starting a
5426 Java application have been fixed. GDB's Java support is now
5427 considered "useable".
5429 * GNU/Linux support for fork, vfork, and exec.
5431 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5432 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5435 * GDB supports logging output to a file
5437 There are two new commands, "set logging" and "show logging", which can be
5438 used to capture GDB's output to a file.
5440 * The meaning of "detach" has changed for gdbserver
5442 The "detach" command will now resume the application, as documented. To
5443 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5446 * d10v, m68hc11 `regs' command deprecated
5448 The `info registers' command has been updated so that it displays the
5449 registers using a format identical to the old `regs' command.
5453 A new command, "maint set profile on/off", has been added. This command can
5454 be used to enable or disable profiling while running GDB, to profile a
5455 session or a set of commands. In addition there is a new configure switch,
5456 "--enable-profiling", which will cause GDB to be compiled with profiling
5457 data, for more informative profiling results.
5459 * Default MI syntax changed to "mi2".
5461 The default MI (machine interface) syntax, enabled by the command line
5462 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5463 "mi1", can be enabled by specifying the option "-i=mi1".
5465 Support for the original "mi0" syntax (included in GDB 5.0) has been
5468 Fix for gdb/192: removed extraneous space when displaying frame level.
5469 Fix for gdb/672: update changelist is now output in mi list format.
5470 Fix for gdb/702: a -var-assign that updates the value now shows up
5471 in a subsequent -var-update.
5473 * New native configurations.
5475 FreeBSD/amd64 x86_64-*-freebsd*
5477 * Multi-arched targets.
5479 HP/PA HPUX11 hppa*-*-hpux*
5480 Renesas M32R/D w/simulator m32r-*-elf*
5482 * OBSOLETE configurations and files
5484 Configurations that have been declared obsolete in this release have
5485 been commented out. Unless there is activity to revive these
5486 configurations, the next release of GDB will have their sources
5487 permanently REMOVED.
5489 Z8000 simulator z8k-zilog-none or z8ksim
5490 Matsushita MN10200 w/simulator mn10200-*-*
5491 H8/500 simulator h8500-hitachi-hms or h8500hms
5492 HP/PA running BSD hppa*-*-bsd*
5493 HP/PA running OSF/1 hppa*-*-osf*
5494 HP/PA Pro target hppa*-*-pro*
5495 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5496 Sequent family i[3456]86-sequent-sysv4*
5497 i[3456]86-sequent-sysv*
5498 i[3456]86-sequent-bsd*
5499 Tsqware Sparclet sparclet-*-*
5500 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5502 * REMOVED configurations and files
5505 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5506 IBM AIX PS/2 i[3456]86-*-aix
5507 i386 running Mach 3.0 i[3456]86-*-mach3*
5508 i386 running Mach i[3456]86-*-mach*
5509 i386 running OSF/1 i[3456]86-*osf1mk*
5510 HP/Apollo 68k Family m68*-apollo*-sysv*,
5512 m68*-hp-bsd*, m68*-hp-hpux*
5513 Argonaut Risc Chip (ARC) arc-*-*
5514 Mitsubishi D30V d30v-*-*
5515 Fujitsu FR30 fr30-*-elf*
5516 OS/9000 i[34]86-*-os9k
5517 I960 with MON960 i960-*-coff
5519 * MIPS $fp behavior changed
5521 The convenience variable $fp, for the MIPS, now consistently returns
5522 the address of the current frame's base. Previously, depending on the
5523 context, $fp could refer to either $sp or the current frame's base
5524 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5525 The GNU Source-Level Debugger''.
5527 *** Changes in GDB 5.3:
5529 * GNU/Linux shared library multi-threaded performance improved.
5531 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5532 `/proc', in preference to `ptrace' for memory reads. This may result
5533 in an improvement in the start-up time of multi-threaded, shared
5534 library applications when run under GDB. One GDB user writes: ``loads
5535 shared libs like mad''.
5537 * ``gdbserver'' now supports multi-threaded applications on some targets
5539 Support for debugging multi-threaded applications which use
5540 the GNU/Linux LinuxThreads package has been added for
5541 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5542 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5544 * GDB now supports C/C++ preprocessor macros.
5546 GDB now expands preprocessor macro invocations in C/C++ expressions,
5547 and provides various commands for showing macro definitions and how
5550 The new command `macro expand EXPRESSION' expands any macro
5551 invocations in expression, and shows the result.
5553 The new command `show macro MACRO-NAME' shows the definition of the
5554 macro named MACRO-NAME, and where it was defined.
5556 Most compilers don't include information about macros in the debugging
5557 information by default. In GCC 3.1, for example, you need to compile
5558 your program with the options `-gdwarf-2 -g3'. If the macro
5559 information is present in the executable, GDB will read it.
5561 * Multi-arched targets.
5563 DEC Alpha (partial) alpha*-*-*
5564 DEC VAX (partial) vax-*-*
5566 National Semiconductor NS32000 (partial) ns32k-*-*
5567 Motorola 68000 (partial) m68k-*-*
5568 Motorola MCORE mcore-*-*
5572 Fujitsu FRV architecture added by Red Hat frv*-*-*
5575 * New native configurations
5577 Alpha NetBSD alpha*-*-netbsd*
5578 SH NetBSD sh*-*-netbsdelf*
5579 MIPS NetBSD mips*-*-netbsd*
5580 UltraSPARC NetBSD sparc64-*-netbsd*
5582 * OBSOLETE configurations and files
5584 Configurations that have been declared obsolete in this release have
5585 been commented out. Unless there is activity to revive these
5586 configurations, the next release of GDB will have their sources
5587 permanently REMOVED.
5589 Mitsubishi D30V d30v-*-*
5590 OS/9000 i[34]86-*-os9k
5591 IBM AIX PS/2 i[3456]86-*-aix
5592 Fujitsu FR30 fr30-*-elf*
5593 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5594 Argonaut Risc Chip (ARC) arc-*-*
5595 i386 running Mach 3.0 i[3456]86-*-mach3*
5596 i386 running Mach i[3456]86-*-mach*
5597 i386 running OSF/1 i[3456]86-*osf1mk*
5598 HP/Apollo 68k Family m68*-apollo*-sysv*,
5600 m68*-hp-bsd*, m68*-hp-hpux*
5601 I960 with MON960 i960-*-coff
5603 * OBSOLETE languages
5605 CHILL, a Pascal like language used by telecommunications companies.
5607 * REMOVED configurations and files
5609 AMD 29k family via UDI a29k-amd-udi, udi29k
5610 A29K VxWorks a29k-*-vxworks
5611 AMD 29000 embedded, using EBMON a29k-none-none
5612 AMD 29000 embedded with COFF a29k-none-coff
5613 AMD 29000 embedded with a.out a29k-none-aout
5615 testsuite/gdb.hp/gdb.threads-hp/ directory
5617 * New command "set max-user-call-depth <nnn>"
5619 This command allows the user to limit the call depth of user-defined
5620 commands. The default is 1024.
5622 * Changes in FreeBSD/i386 native debugging.
5624 Support for the "generate-core-file" has been added.
5626 * New commands "dump", "append", and "restore".
5628 These commands allow data to be copied from target memory
5629 to a bfd-format or binary file (dump and append), and back
5630 from a file into memory (restore).
5632 * Improved "next/step" support on multi-processor Alpha Tru64.
5634 The previous single-step mechanism could cause unpredictable problems,
5635 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5636 of a software single-step mechanism prevents this.
5638 *** Changes in GDB 5.2.1:
5646 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5647 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5648 Fix, by Joel Brobecker imported from mainline.
5650 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5651 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5652 Fix, by Fred Fish, imported from mainline.
5654 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5655 Surprisingly enough, it works now.
5656 By Michal Ludvig, imported from mainline.
5658 i386 hardware watchpoint support:
5659 avoid misses on second run for some targets.
5660 By Pierre Muller, imported from mainline.
5662 *** Changes in GDB 5.2:
5664 * New command "set trust-readonly-sections on[off]".
5666 This command is a hint that tells gdb that read-only sections
5667 really are read-only (ie. that their contents will not change).
5668 In this mode, gdb will go to the object file rather than the
5669 target to read memory from read-only sections (such as ".text").
5670 This can be a significant performance improvement on some
5671 (notably embedded) targets.
5673 * New command "generate-core-file" (or "gcore").
5675 This new gdb command allows the user to drop a core file of the child
5676 process state at any time. So far it's been implemented only for
5677 GNU/Linux and Solaris, but should be relatively easily ported to other
5678 hosts. Argument is core file name (defaults to core.<pid>).
5680 * New command line option
5682 GDB now accepts --pid or -p followed by a process id.
5684 * Change in command line behavior -- corefiles vs. process ids.
5686 There is a subtle behavior in the way in which GDB handles
5687 command line arguments. The first non-flag argument is always
5688 a program to debug, but the second non-flag argument may either
5689 be a corefile or a process id. Previously, GDB would attempt to
5690 open the second argument as a corefile, and if that failed, would
5691 issue a superfluous error message and then attempt to attach it as
5692 a process. Now, if the second argument begins with a non-digit,
5693 it will be treated as a corefile. If it begins with a digit,
5694 GDB will attempt to attach it as a process, and if no such process
5695 is found, will then attempt to open it as a corefile.
5697 * Changes in ARM configurations.
5699 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5700 configuration is fully multi-arch.
5702 * New native configurations
5704 ARM NetBSD arm*-*-netbsd*
5705 x86 OpenBSD i[3456]86-*-openbsd*
5706 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5707 Sparc64 running FreeBSD sparc64-*-freebsd*
5711 Sanyo XStormy16 xstormy16-elf
5713 * OBSOLETE configurations and files
5715 Configurations that have been declared obsolete in this release have
5716 been commented out. Unless there is activity to revive these
5717 configurations, the next release of GDB will have their sources
5718 permanently REMOVED.
5720 AMD 29k family via UDI a29k-amd-udi, udi29k
5721 A29K VxWorks a29k-*-vxworks
5722 AMD 29000 embedded, using EBMON a29k-none-none
5723 AMD 29000 embedded with COFF a29k-none-coff
5724 AMD 29000 embedded with a.out a29k-none-aout
5726 testsuite/gdb.hp/gdb.threads-hp/ directory
5728 * REMOVED configurations and files
5730 TI TMS320C80 tic80-*-*
5732 PowerPC Solaris powerpcle-*-solaris*
5733 PowerPC Windows NT powerpcle-*-cygwin32
5734 PowerPC Netware powerpc-*-netware*
5735 Harris/CXUX m88k m88*-harris-cxux*
5736 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5737 ns32k-utek-sysv* ns32k-utek-*
5738 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5739 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5740 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5741 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5742 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5744 * Changes to command line processing
5746 The new `--args' feature can be used to specify command-line arguments
5747 for the inferior from gdb's command line.
5749 * Changes to key bindings
5751 There is a new `operate-and-get-next' function bound to `C-o'.
5753 *** Changes in GDB 5.1.1
5755 Fix compile problem on DJGPP.
5757 Fix a problem with floating-point registers on the i386 being
5760 Fix to stop GDB crashing on .debug_str debug info.
5762 Numerous documentation fixes.
5764 Numerous testsuite fixes.
5766 *** Changes in GDB 5.1:
5768 * New native configurations
5770 Alpha FreeBSD alpha*-*-freebsd*
5771 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5772 MIPS GNU/Linux mips*-*-linux*
5773 MIPS SGI Irix 6.x mips*-sgi-irix6*
5774 ia64 AIX ia64-*-aix*
5775 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5779 Motorola 68HC11 and 68HC12 m68hc11-elf
5781 UltraSparc running GNU/Linux sparc64-*-linux*
5783 * OBSOLETE configurations and files
5785 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5786 Harris/CXUX m88k m88*-harris-cxux*
5787 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5788 ns32k-utek-sysv* ns32k-utek-*
5789 TI TMS320C80 tic80-*-*
5791 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5792 PowerPC Solaris powerpcle-*-solaris*
5793 PowerPC Windows NT powerpcle-*-cygwin32
5794 PowerPC Netware powerpc-*-netware*
5795 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5796 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5797 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5798 Apple Macintosh (MPW) host N/A
5800 stuff.c (Program to stuff files into a specially prepared space in kdb)
5801 kdb-start.c (Main loop for the standalone kernel debugger)
5803 Configurations that have been declared obsolete in this release have
5804 been commented out. Unless there is activity to revive these
5805 configurations, the next release of GDB will have their sources
5806 permanently REMOVED.
5808 * REMOVED configurations and files
5810 Altos 3068 m68*-altos-*
5811 Convex c1-*-*, c2-*-*
5813 ARM RISCix arm-*-* (as host)
5817 * GDB has been converted to ISO C.
5819 GDB's source code has been converted to ISO C. In particular, the
5820 sources are fully protoized, and rely on standard headers being
5825 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5827 * The MI enabled by default.
5829 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5830 revised and enabled by default. Packages which use GDB as a debugging
5831 engine behind a UI or another front end are encouraged to switch to
5832 using the GDB/MI interface, instead of the old annotations interface
5833 which is now deprecated.
5835 * Support for debugging Pascal programs.
5837 GDB now includes support for debugging Pascal programs. The following
5838 main features are supported:
5840 - Pascal-specific data types such as sets;
5842 - automatic recognition of Pascal sources based on file-name
5845 - Pascal-style display of data types, variables, and functions;
5847 - a Pascal expression parser.
5849 However, some important features are not yet supported.
5851 - Pascal string operations are not supported at all;
5853 - there are some problems with boolean types;
5855 - Pascal type hexadecimal constants are not supported
5856 because they conflict with the internal variables format;
5858 - support for Pascal objects and classes is not full yet;
5860 - unlike Pascal, GDB is case-sensitive for symbol names.
5862 * Changes in completion.
5864 Commands such as `shell', `run' and `set args', which pass arguments
5865 to inferior programs, now complete on file names, similar to what
5866 users expect at the shell prompt.
5868 Commands which accept locations, such as `disassemble', `print',
5869 `breakpoint', `until', etc. now complete on filenames as well as
5870 program symbols. Thus, if you type "break foob TAB", and the source
5871 files linked into the programs include `foobar.c', that file name will
5872 be one of the candidates for completion. However, file names are not
5873 considered for completion after you typed a colon that delimits a file
5874 name from a name of a function in that file, as in "break foo.c:bar".
5876 `set demangle-style' completes on available demangling styles.
5878 * New platform-independent commands:
5880 It is now possible to define a post-hook for a command as well as a
5881 hook that runs before the command. For more details, see the
5882 documentation of `hookpost' in the GDB manual.
5884 * Changes in GNU/Linux native debugging.
5886 Support for debugging multi-threaded programs has been completely
5887 revised for all platforms except m68k and sparc. You can now debug as
5888 many threads as your system allows you to have.
5890 Attach/detach is supported for multi-threaded programs.
5892 Support for SSE registers was added for x86. This doesn't work for
5893 multi-threaded programs though.
5895 * Changes in MIPS configurations.
5897 Multi-arch support is enabled for all MIPS configurations.
5899 GDB can now be built as native debugger on SGI Irix 6.x systems for
5900 debugging n32 executables. (Debugging 64-bit executables is not yet
5903 * Unified support for hardware watchpoints in all x86 configurations.
5905 Most (if not all) native x86 configurations support hardware-assisted
5906 breakpoints and watchpoints in a unified manner. This support
5907 implements debug register sharing between watchpoints, which allows to
5908 put a virtually infinite number of watchpoints on the same address,
5909 and also supports watching regions up to 16 bytes with several debug
5912 The new maintenance command `maintenance show-debug-regs' toggles
5913 debugging print-outs in functions that insert, remove, and test
5914 watchpoints and hardware breakpoints.
5916 * Changes in the DJGPP native configuration.
5918 New command ``info dos sysinfo'' displays assorted information about
5919 the CPU, OS, memory, and DPMI server.
5921 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5922 display information about segment descriptors stored in GDT, LDT, and
5925 New commands ``info dos pde'' and ``info dos pte'' display entries
5926 from Page Directory and Page Tables (for now works with CWSDPMI only).
5927 New command ``info dos address-pte'' displays the Page Table entry for
5928 a given linear address.
5930 GDB can now pass command lines longer than 126 characters to the
5931 program being debugged (requires an update to the libdbg.a library
5932 which is part of the DJGPP development kit).
5934 DWARF2 debug info is now supported.
5936 It is now possible to `step' and `next' through calls to `longjmp'.
5938 * Changes in documentation.
5940 All GDB documentation was converted to GFDL, the GNU Free
5941 Documentation License.
5943 Tracepoints-related commands are now fully documented in the GDB
5946 TUI, the Text-mode User Interface, is now documented in the manual.
5948 Tracepoints-related commands are now fully documented in the GDB
5951 The "GDB Internals" manual now has an index. It also includes
5952 documentation of `ui_out' functions, GDB coding standards, x86
5953 hardware watchpoints, and memory region attributes.
5955 * GDB's version number moved to ``version.in''
5957 The Makefile variable VERSION has been replaced by the file
5958 ``version.in''. People creating GDB distributions should update the
5959 contents of this file.
5963 GUD support is now a standard part of the EMACS distribution.
5965 *** Changes in GDB 5.0:
5967 * Improved support for debugging FP programs on x86 targets
5969 Unified and much-improved support for debugging floating-point
5970 programs on all x86 targets. In particular, ``info float'' now
5971 displays the FP registers in the same format on all x86 targets, with
5972 greater level of detail.
5974 * Improvements and bugfixes in hardware-assisted watchpoints
5976 It is now possible to watch array elements, struct members, and
5977 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5978 on x86 targets no longer erroneously trigger when the address is
5981 * Improvements in the native DJGPP version of GDB
5983 The distribution now includes all the scripts and auxiliary files
5984 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5985 machines ``out of the box''.
5987 The DJGPP version can now debug programs that use signals. It is
5988 possible to catch signals that happened in the debuggee, deliver
5989 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5990 would kill the program being debugged.) Programs that hook hardware
5991 interrupts (keyboard, timer, etc.) can also be debugged.
5993 It is now possible to debug DJGPP programs that redirect their
5994 standard handles or switch them to raw (as opposed to cooked) mode, or
5995 even close them. The command ``run < foo > bar'' works as expected,
5996 and ``info terminal'' reports useful information about the debuggee's
5997 terminal, including raw/cooked mode, redirection, etc.
5999 The DJGPP version now uses termios functions for console I/O, which
6000 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6003 DOS-style file names with drive letters are now fully supported by
6006 It is now possible to debug DJGPP programs that switch their working
6007 directory. It is also possible to rerun the debuggee any number of
6008 times without restarting GDB; thus, you can use the same setup,
6009 breakpoints, etc. for many debugging sessions.
6011 * New native configurations
6013 ARM GNU/Linux arm*-*-linux*
6014 PowerPC GNU/Linux powerpc-*-linux*
6018 Motorola MCore mcore-*-*
6019 x86 VxWorks i[3456]86-*-vxworks*
6020 PowerPC VxWorks powerpc-*-vxworks*
6021 TI TMS320C80 tic80-*-*
6023 * OBSOLETE configurations
6025 Altos 3068 m68*-altos-*
6026 Convex c1-*-*, c2-*-*
6028 ARM RISCix arm-*-* (as host)
6031 Configurations that have been declared obsolete will be commented out,
6032 but the code will be left in place. If there is no activity to revive
6033 these configurations before the next release of GDB, the sources will
6034 be permanently REMOVED.
6036 * Gould support removed
6038 Support for the Gould PowerNode and NP1 has been removed.
6040 * New features for SVR4
6042 On SVR4 native platforms (such as Solaris), if you attach to a process
6043 without first loading a symbol file, GDB will now attempt to locate and
6044 load symbols from the running process's executable file.
6046 * Many C++ enhancements
6048 C++ support has been greatly improved. Overload resolution now works properly
6049 in almost all cases. RTTI support is on the way.
6051 * Remote targets can connect to a sub-program
6053 A popen(3) style serial-device has been added. This device starts a
6054 sub-process (such as a stand-alone simulator) and then communicates
6055 with that. The sub-program to run is specified using the syntax
6056 ``|<program> <args>'' vis:
6058 (gdb) set remotedebug 1
6059 (gdb) target extended-remote |mn10300-elf-sim program-args
6061 * MIPS 64 remote protocol
6063 A long standing bug in the mips64 remote protocol where by GDB
6064 expected certain 32 bit registers (ex SR) to be transfered as 32
6065 instead of 64 bits has been fixed.
6067 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6068 added to provide backward compatibility with older versions of GDB.
6070 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6072 The command ``set remotebinarydownload'' command has been replaced by
6073 ``set remote X-packet''. Other commands in ``set remote'' family
6074 include ``set remote P-packet''.
6076 * Breakpoint commands accept ranges.
6078 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6079 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6080 ``tracepoint passcount'' also accepts a range of tracepoints.
6082 * ``apropos'' command added.
6084 The ``apropos'' command searches through command names and
6085 documentation strings, printing out matches, making it much easier to
6086 try to find a command that does what you are looking for.
6090 A new machine oriented interface (MI) has been added to GDB. This
6091 interface is designed for debug environments running GDB as a separate
6092 process. This is part of the long term libGDB project. See the
6093 "GDB/MI" chapter of the GDB manual for further information. It can be
6094 enabled by configuring with:
6096 .../configure --enable-gdbmi
6098 *** Changes in GDB-4.18:
6100 * New native configurations
6102 HP-UX 10.20 hppa*-*-hpux10.20
6103 HP-UX 11.x hppa*-*-hpux11.0*
6104 M68K GNU/Linux m68*-*-linux*
6108 Fujitsu FR30 fr30-*-elf*
6109 Intel StrongARM strongarm-*-*
6110 Mitsubishi D30V d30v-*-*
6112 * OBSOLETE configurations
6114 Gould PowerNode, NP1 np1-*-*, pn-*-*
6116 Configurations that have been declared obsolete will be commented out,
6117 but the code will be left in place. If there is no activity to revive
6118 these configurations before the next release of GDB, the sources will
6119 be permanently REMOVED.
6123 As a compatibility experiment, GDB's source files buildsym.h and
6124 buildsym.c have been converted to pure standard C, no longer
6125 containing any K&R compatibility code. We believe that all systems in
6126 use today either come with a standard C compiler, or have a GCC port
6127 available. If this is not true, please report the affected
6128 configuration to bug-gdb@gnu.org immediately. See the README file for
6129 information about getting a standard C compiler if you don't have one
6134 GDB now uses readline 2.2.
6136 * set extension-language
6138 You can now control the mapping between filename extensions and source
6139 languages by using the `set extension-language' command. For instance,
6140 you can ask GDB to treat .c files as C++ by saying
6141 set extension-language .c c++
6142 The command `info extensions' lists all of the recognized extensions
6143 and their associated languages.
6145 * Setting processor type for PowerPC and RS/6000
6147 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6148 you can use the `set processor' command to specify what variant of the
6149 PowerPC family you are debugging. The command
6153 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6154 following PowerPC and RS6000 variants:
6156 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6157 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6159 403GC IBM PowerPC 403GC
6160 505 Motorola PowerPC 505
6161 860 Motorola PowerPC 860 or 850
6162 601 Motorola PowerPC 601
6163 602 Motorola PowerPC 602
6164 603 Motorola/IBM PowerPC 603 or 603e
6165 604 Motorola PowerPC 604 or 604e
6166 750 Motorola/IBM PowerPC 750 or 750
6168 At the moment, this command just tells GDB what to name the
6169 special-purpose processor registers. Since almost all the affected
6170 registers are inaccessible to user-level programs, this command is
6171 only useful for remote debugging in its present form.
6175 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6176 more extensive support for HP-UX. Added features include shared
6177 library support, kernel threads and hardware watchpoints for 11.00,
6178 support for HP's ANSI C and C++ compilers, and a compatibility mode
6179 for xdb and dbx commands.
6183 HP's donation includes the new concept of catchpoints, which is a
6184 generalization of the old catch command. On HP-UX, it is now possible
6185 to catch exec, fork, and vfork, as well as library loading.
6187 This means that the existing catch command has changed; its first
6188 argument now specifies the type of catch to be set up. See the
6189 output of "help catch" for a list of catchpoint types.
6191 * Debugging across forks
6193 On HP-UX, you can choose which process to debug when a fork() happens
6198 HP has donated a curses-based terminal user interface (TUI). To get
6199 it, build with --enable-tui. Although this can be enabled for any
6200 configuration, at present it only works for native HP debugging.
6202 * GDB remote protocol additions
6204 A new protocol packet 'X' that writes binary data is now available.
6205 Default behavior is to try 'X', then drop back to 'M' if the stub
6206 fails to respond. The settable variable `remotebinarydownload'
6207 allows explicit control over the use of 'X'.
6209 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6210 full 64-bit address. The command
6212 set remoteaddresssize 32
6214 can be used to revert to the old behaviour. For existing remote stubs
6215 the change should not be noticed, as the additional address information
6218 In order to assist in debugging stubs, you may use the maintenance
6219 command `packet' to send any text string to the stub. For instance,
6221 maint packet heythere
6223 sends the packet "$heythere#<checksum>". Note that it is very easy to
6224 disrupt a debugging session by sending the wrong packet at the wrong
6227 The compare-sections command allows you to compare section data on the
6228 target to what is in the executable file without uploading or
6229 downloading, by comparing CRC checksums.
6231 * Tracing can collect general expressions
6233 You may now collect general expressions at tracepoints. This requires
6234 further additions to the target-side stub; see tracepoint.c and
6235 doc/agentexpr.texi for further details.
6237 * mask-address variable for Mips
6239 For Mips targets, you may control the zeroing of the upper 32 bits of
6240 a 64-bit address by entering `set mask-address on'. This is mainly
6241 of interest to users of embedded R4xxx and R5xxx processors.
6243 * Higher serial baud rates
6245 GDB's serial code now allows you to specify baud rates 57600, 115200,
6246 230400, and 460800 baud. (Note that your host system may not be able
6247 to achieve all of these rates.)
6251 The i960 configuration now includes an initial implementation of a
6252 builtin simulator, contributed by Jim Wilson.
6255 *** Changes in GDB-4.17:
6257 * New native configurations
6259 Alpha GNU/Linux alpha*-*-linux*
6260 Unixware 2.x i[3456]86-unixware2*
6261 Irix 6.x mips*-sgi-irix6*
6262 PowerPC GNU/Linux powerpc-*-linux*
6263 PowerPC Solaris powerpcle-*-solaris*
6264 Sparc GNU/Linux sparc-*-linux*
6265 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6269 Argonaut Risc Chip (ARC) arc-*-*
6270 Hitachi H8/300S h8300*-*-*
6271 Matsushita MN10200 w/simulator mn10200-*-*
6272 Matsushita MN10300 w/simulator mn10300-*-*
6273 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6274 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6275 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6276 Mitsubishi D10V w/simulator d10v-*-*
6277 Mitsubishi M32R/D w/simulator m32r-*-elf*
6278 Tsqware Sparclet sparclet-*-*
6279 NEC V850 w/simulator v850-*-*
6281 * New debugging protocols
6283 ARM with RDI protocol arm*-*-*
6284 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6285 DDB and LSI variants of PMON protocol mips*-*-*
6286 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6287 PowerPC with SDS protocol powerpc{,le}-*-eabi
6288 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6292 All configurations can now understand and use the DWARF 2 debugging
6293 format. The choice is automatic, if the symbol file contains DWARF 2
6298 GDB now includes basic Java language support. This support is
6299 only useful with Java compilers that produce native machine code.
6301 * solib-absolute-prefix and solib-search-path
6303 For SunOS and SVR4 shared libraries, you may now set the prefix for
6304 loading absolute shared library symbol files, and the search path for
6305 locating non-absolute shared library symbol files.
6307 * Live range splitting
6309 GDB can now effectively debug code for which GCC has performed live
6310 range splitting as part of its optimization. See gdb/doc/LRS for
6311 more details on the expected format of the stabs information.
6315 GDB's support for the GNU Hurd, including thread debugging, has been
6316 updated to work with current versions of the Hurd.
6320 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6321 instruction set. ARM GDB automatically detects when Thumb
6322 instructions are in use, and adjusts disassembly and backtracing
6327 GDB's MIPS target configurations now handle the MIP16 16-bit
6332 GDB now includes support for overlays; if an executable has been
6333 linked such that multiple sections are based at the same address, GDB
6334 will decide which section to use for symbolic info. You can choose to
6335 control the decision manually, using overlay commands, or implement
6336 additional target-side support and use "overlay load-target" to bring
6337 in the overlay mapping. Do "help overlay" for more detail.
6341 The command "info symbol <address>" displays information about
6342 the symbol at the specified address.
6346 The standard remote protocol now includes an extension that allows
6347 asynchronous collection and display of trace data. This requires
6348 extensive support in the target-side debugging stub. Tracing mode
6349 includes a new interaction mode in GDB and new commands: see the
6350 file tracepoint.c for more details.
6354 Configurations for embedded MIPS now include a simulator contributed
6355 by Cygnus Solutions. The simulator supports the instruction sets
6356 of most MIPS variants.
6360 Sparc configurations may now include the ERC32 simulator contributed
6361 by the European Space Agency. The simulator is not built into
6362 Sparc targets by default; configure with --enable-sim to include it.
6366 For target configurations that may include multiple variants of a
6367 basic architecture (such as MIPS and SH), you may now set the
6368 architecture explicitly. "set arch" sets, "info arch" lists
6369 the possible architectures.
6371 *** Changes in GDB-4.16:
6373 * New native configurations
6375 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6376 M68K NetBSD m68k-*-netbsd*
6377 PowerPC AIX 4.x powerpc-*-aix*
6378 PowerPC MacOS powerpc-*-macos*
6379 PowerPC Windows NT powerpcle-*-cygwin32
6380 RS/6000 AIX 4.x rs6000-*-aix4*
6384 ARM with RDP protocol arm-*-*
6385 I960 with MON960 i960-*-coff
6386 MIPS VxWorks mips*-*-vxworks*
6387 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6388 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6390 Matra Sparclet sparclet-*-*
6394 The powerpc-eabi configuration now includes the PSIM simulator,
6395 contributed by Andrew Cagney, with assistance from Mike Meissner.
6396 PSIM is a very elaborate model of the PowerPC, including not only
6397 basic instruction set execution, but also details of execution unit
6398 performance and I/O hardware. See sim/ppc/README for more details.
6402 GDB now works with Solaris 2.5.
6404 * Windows 95/NT native
6406 GDB will now work as a native debugger on Windows 95 and Windows NT.
6407 To build it from source, you must use the "gnu-win32" environment,
6408 which uses a DLL to emulate enough of Unix to run the GNU tools.
6409 Further information, binaries, and sources are available at
6410 ftp.cygnus.com, under pub/gnu-win32.
6412 * dont-repeat command
6414 If a user-defined command includes the command `dont-repeat', then the
6415 command will not be repeated if the user just types return. This is
6416 useful if the command is time-consuming to run, so that accidental
6417 extra keystrokes don't run the same command many times.
6419 * Send break instead of ^C
6421 The standard remote protocol now includes an option to send a break
6422 rather than a ^C to the target in order to interrupt it. By default,
6423 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6425 * Remote protocol timeout
6427 The standard remote protocol includes a new variable `remotetimeout'
6428 that allows you to set the number of seconds before GDB gives up trying
6429 to read from the target. The default value is 2.
6431 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6433 By default GDB will automatically keep track of objects as they are
6434 loaded and unloaded by the dynamic linker. By using the command `set
6435 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6436 when shared library events occur, thus allowing you to set breakpoints
6437 in shared libraries which are explicitly loaded by the inferior.
6439 Note this feature does not work on hpux8. On hpux9 you must link
6440 /usr/lib/end.o into your program. This feature should work
6441 automatically on hpux10.
6443 * Irix 5.x hardware watchpoint support
6445 Irix 5 configurations now support the use of hardware watchpoints.
6447 * Mips protocol "SYN garbage limit"
6449 When debugging a Mips target using the `target mips' protocol, you
6450 may set the number of characters that GDB will ignore by setting
6451 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6452 every character. The default value is 1050.
6454 * Recording and replaying remote debug sessions
6456 If you set `remotelogfile' to the name of a file, gdb will write to it
6457 a recording of a remote debug session. This recording may then be
6458 replayed back to gdb using "gdbreplay". See gdbserver/README for
6459 details. This is useful when you have a problem with GDB while doing
6460 remote debugging; you can make a recording of the session and send it
6461 to someone else, who can then recreate the problem.
6463 * Speedups for remote debugging
6465 GDB includes speedups for downloading and stepping MIPS systems using
6466 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6467 and more efficient S-record downloading.
6469 * Memory use reductions and statistics collection
6471 GDB now uses less memory and reports statistics about memory usage.
6472 Try the `maint print statistics' command, for example.
6474 *** Changes in GDB-4.15:
6476 * Psymtabs for XCOFF
6478 The symbol reader for AIX GDB now uses partial symbol tables. This
6479 can greatly improve startup time, especially for large executables.
6481 * Remote targets use caching
6483 Remote targets now use a data cache to speed up communication with the
6484 remote side. The data cache could lead to incorrect results because
6485 it doesn't know about volatile variables, thus making it impossible to
6486 debug targets which use memory mapped I/O devices. `set remotecache
6487 off' turns the the data cache off.
6489 * Remote targets may have threads
6491 The standard remote protocol now includes support for multiple threads
6492 in the target system, using new protocol commands 'H' and 'T'. See
6493 gdb/remote.c for details.
6497 If GDB is configured with `--enable-netrom', then it will include
6498 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6499 acts as though it is a bank of ROM on the target board, but you can
6500 write into it over the network. GDB's support consists only of
6501 support for fast loading into the emulated ROM; to debug, you must use
6502 another protocol, such as standard remote protocol. The usual
6503 sequence is something like
6505 target nrom <netrom-hostname>
6507 target remote <netrom-hostname>:1235
6511 GDB now includes support for the Apple Macintosh, as a host only. It
6512 may be run as either an MPW tool or as a standalone application, and
6513 it can debug through the serial port. All the usual GDB commands are
6514 available, but to the target command, you must supply "serial" as the
6515 device type instead of "/dev/ttyXX". See mpw-README in the main
6516 directory for more information on how to build. The MPW configuration
6517 scripts */mpw-config.in support only a few targets, and only the
6518 mips-idt-ecoff target has been tested.
6522 GDB configuration now uses autoconf. This is not user-visible,
6523 but does simplify configuration and building.
6527 GDB now supports hpux10.
6529 *** Changes in GDB-4.14:
6531 * New native configurations
6533 x86 FreeBSD i[345]86-*-freebsd
6534 x86 NetBSD i[345]86-*-netbsd
6535 NS32k NetBSD ns32k-*-netbsd
6536 Sparc NetBSD sparc-*-netbsd
6540 A29K VxWorks a29k-*-vxworks
6541 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6542 CPU32 EST-300 emulator m68*-*-est*
6543 PowerPC ELF powerpc-*-elf
6546 * Alpha OSF/1 support for procfs
6548 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6549 possible to attach to running processes. As the mounting of the /proc
6550 filesystem is optional on the Alpha, GDB automatically determines
6551 the availability of /proc during startup. This can lead to problems
6552 if /proc is unmounted after GDB has been started.
6554 * Arguments to user-defined commands
6556 User commands may accept up to 10 arguments separated by whitespace.
6557 Arguments are accessed within the user command via $arg0..$arg9. A
6560 print $arg0 + $arg1 + $arg2
6562 To execute the command use:
6565 Defines the command "adder" which prints the sum of its three arguments.
6566 Note the arguments are text substitutions, so they may reference variables,
6567 use complex expressions, or even perform inferior function calls.
6569 * New `if' and `while' commands
6571 This makes it possible to write more sophisticated user-defined
6572 commands. Both commands take a single argument, which is the
6573 expression to evaluate, and must be followed by the commands to
6574 execute, one per line, if the expression is nonzero, the list being
6575 terminated by the word `end'. The `if' command list may include an
6576 `else' word, which causes the following commands to be executed only
6577 if the expression is zero.
6579 * Fortran source language mode
6581 GDB now includes partial support for Fortran 77. It will recognize
6582 Fortran programs and can evaluate a subset of Fortran expressions, but
6583 variables and functions may not be handled correctly. GDB will work
6584 with G77, but does not yet know much about symbols emitted by other
6587 * Better HPUX support
6589 Most debugging facilities now work on dynamic executables for HPPAs
6590 running hpux9 or later. You can attach to running dynamically linked
6591 processes, but by default the dynamic libraries will be read-only, so
6592 for instance you won't be able to put breakpoints in them. To change
6593 that behavior do the following before running the program:
6599 This will cause the libraries to be mapped private and read-write.
6600 To revert to the normal behavior, do this:
6606 You cannot set breakpoints or examine data in the library until after
6607 the library is loaded if the function/data symbols do not have
6610 GDB can now also read debug symbols produced by the HP C compiler on
6611 HPPAs (sorry, no C++, Fortran or 68k support).
6613 * Target byte order now dynamically selectable
6615 You can choose which byte order to use with a target system, via the
6616 commands "set endian big" and "set endian little", and you can see the
6617 current setting by using "show endian". You can also give the command
6618 "set endian auto", in which case GDB will use the byte order
6619 associated with the executable. Currently, only embedded MIPS
6620 configurations support dynamic selection of target byte order.
6622 * New DOS host serial code
6624 This version uses DPMI interrupts to handle buffered I/O, so you
6625 no longer need to run asynctsr when debugging boards connected to
6628 *** Changes in GDB-4.13:
6630 * New "complete" command
6632 This lists all the possible completions for the rest of the line, if it
6633 were to be given as a command itself. This is intended for use by emacs.
6635 * Trailing space optional in prompt
6637 "set prompt" no longer adds a space for you after the prompt you set. This
6638 allows you to set a prompt which ends in a space or one that does not.
6640 * Breakpoint hit counts
6642 "info break" now displays a count of the number of times the breakpoint
6643 has been hit. This is especially useful in conjunction with "ignore"; you
6644 can ignore a large number of breakpoint hits, look at the breakpoint info
6645 to see how many times the breakpoint was hit, then run again, ignoring one
6646 less than that number, and this will get you quickly to the last hit of
6649 * Ability to stop printing at NULL character
6651 "set print null-stop" will cause GDB to stop printing the characters of
6652 an array when the first NULL is encountered. This is useful when large
6653 arrays actually contain only short strings.
6655 * Shared library breakpoints
6657 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6658 breakpoints in shared libraries before the executable is run.
6660 * Hardware watchpoints
6662 There is a new hardware breakpoint for the watch command for sparclite
6663 targets. See gdb/sparclite/hw_breakpoint.note.
6665 Hardware watchpoints are also now supported under GNU/Linux.
6669 Annotations have been added. These are for use with graphical interfaces,
6670 and are still experimental. Currently only gdba.el uses these.
6672 * Improved Irix 5 support
6674 GDB now works properly with Irix 5.2.
6676 * Improved HPPA support
6678 GDB now works properly with the latest GCC and GAS.
6680 * New native configurations
6682 Sequent PTX4 i[34]86-sequent-ptx4
6683 HPPA running OSF/1 hppa*-*-osf*
6684 Atari TT running SVR4 m68*-*-sysv4*
6685 RS/6000 LynxOS rs6000-*-lynxos*
6689 OS/9000 i[34]86-*-os9k
6690 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6693 * Hitachi SH7000 and E7000-PC ICE support
6695 There is now support for communicating with the Hitachi E7000-PC ICE.
6696 This is available automatically when GDB is configured for the SH.
6700 As usual, a variety of small fixes and improvements, both generic
6701 and configuration-specific. See the ChangeLog for more detail.
6703 *** Changes in GDB-4.12:
6705 * Irix 5 is now supported
6709 GDB-4.12 on the HPPA has a number of changes which make it unable
6710 to debug the output from the currently released versions of GCC and
6711 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6712 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6713 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6716 *** Changes in GDB-4.11:
6718 * User visible changes:
6722 The "set remotedebug" option is now consistent between the mips remote
6723 target, remote targets using the gdb-specific protocol, UDI (AMD's
6724 debug protocol for the 29k) and the 88k bug monitor. It is now an
6725 integer specifying a debug level (normally 0 or 1, but 2 means more
6726 debugging info for the mips target).
6728 * DEC Alpha native support
6730 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6731 debug info, but GDB works fairly well with the DEC compiler and should
6732 work with a future GCC release. See the README file for a few
6733 Alpha-specific notes.
6735 * Preliminary thread implementation
6737 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6739 * LynxOS native and target support for 386
6741 This release has been hosted on LynxOS 2.2, and also can be configured
6742 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6745 * Improvements in C++ mangling/demangling.
6747 This release has much better g++ debugging, specifically in name
6748 mangling/demangling, virtual function calls, print virtual table,
6749 call methods, ...etc.
6751 *** Changes in GDB-4.10:
6753 * User visible changes:
6755 Remote debugging using the GDB-specific (`target remote') protocol now
6756 supports the `load' command. This is only useful if you have some
6757 other way of getting the stub to the target system, and you can put it
6758 somewhere in memory where it won't get clobbered by the download.
6760 Filename completion now works.
6762 When run under emacs mode, the "info line" command now causes the
6763 arrow to point to the line specified. Also, "info line" prints
6764 addresses in symbolic form (as well as hex).
6766 All vxworks based targets now support a user settable option, called
6767 vxworks-timeout. This option represents the number of seconds gdb
6768 should wait for responses to rpc's. You might want to use this if
6769 your vxworks target is, perhaps, a slow software simulator or happens
6770 to be on the far side of a thin network line.
6774 This release contains support for using a DEC alpha as a GDB host for
6775 cross debugging. Native alpha debugging is not supported yet.
6778 *** Changes in GDB-4.9:
6782 This is the first GDB release which is accompanied by a matching testsuite.
6783 The testsuite requires installation of dejagnu, which should be available
6784 via ftp from most sites that carry GNU software.
6788 'Cfront' style demangling has had its name changed to 'ARM' style, to
6789 emphasize that it was written from the specifications in the C++ Annotated
6790 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6791 disclaimers, it still generated too much confusion with users attempting to
6792 use gdb with AT&T cfront.
6796 GDB now uses a standard remote interface to a simulator library.
6797 So far, the library contains simulators for the Zilog Z8001/2, the
6798 Hitachi H8/300, H8/500 and Super-H.
6800 * New targets supported
6802 H8/300 simulator h8300-hitachi-hms or h8300hms
6803 H8/500 simulator h8500-hitachi-hms or h8500hms
6804 SH simulator sh-hitachi-hms or sh
6805 Z8000 simulator z8k-zilog-none or z8ksim
6806 IDT MIPS board over serial line mips-idt-ecoff
6808 Cross-debugging to GO32 targets is supported. It requires a custom
6809 version of the i386-stub.c module which is integrated with the
6810 GO32 memory extender.
6812 * New remote protocols
6814 MIPS remote debugging protocol.
6816 * New source languages supported
6818 This version includes preliminary support for Chill, a Pascal like language
6819 used by telecommunications companies. Chill support is also being integrated
6820 into the GNU compiler, but we don't know when it will be publically available.
6823 *** Changes in GDB-4.8:
6825 * HP Precision Architecture supported
6827 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6828 version of this support was available as a set of patches from the
6829 University of Utah. GDB does not support debugging of programs
6830 compiled with the HP compiler, because HP will not document their file
6831 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6832 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6834 Many problems in the preliminary version have been fixed.
6836 * Faster and better demangling
6838 We have improved template demangling and fixed numerous bugs in the GNU style
6839 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6840 character types (wchar_t) are now supported. Demangling of each symbol is now
6841 only done once, and is cached when the symbol table for a file is read in.
6842 This results in a small increase in memory usage for C programs, a moderate
6843 increase in memory usage for C++ programs, and a fantastic speedup in
6846 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6847 from the specifications in the Annotated Reference Manual, which AT&T's
6848 compiler does not actually implement.
6850 * G++ multiple inheritance compiler problem
6852 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6853 inheritance lattices was reworked to properly discover ambiguities. We
6854 recently found an example which causes this new algorithm to fail in a
6855 very subtle way, producing bad debug information for those classes.
6856 The file 'gcc.patch' (in this directory) can be applied to gcc to
6857 circumvent the problem. A future GCC release will contain a complete
6860 The previous G++ debug info problem (mentioned below for the gdb-4.7
6861 release) is fixed in gcc version 2.3.2.
6863 * Improved configure script
6865 The `configure' script will now attempt to guess your system type if
6866 you don't supply a host system type. The old scheme of supplying a
6867 host system triplet is preferable over using this. All the magic is
6868 done in the new `config.guess' script. Examine it for details.
6870 We have also brought our configure script much more in line with the FSF's
6871 version. It now supports the --with-xxx options. In particular,
6872 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6873 The resulting GDB will not be able to read arbitrary object file formats --
6874 only the format ``expected'' to be used on the configured target system.
6875 We hope to make this the default in a future release.
6877 * Documentation improvements
6879 There's new internal documentation on how to modify GDB, and how to
6880 produce clean changes to the code. We implore people to read it
6881 before submitting changes.
6883 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6884 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6885 `info' files are also provided. To build `info' files from scratch,
6886 you will need the latest `makeinfo' release, which will be available in
6887 a future texinfo-X.Y release.
6889 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6890 We're not sure exactly which versions have this problem, but it has
6891 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6892 or better. If that isn't possible, there is a patch in
6893 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6894 around this problem.
6898 GDB now supports array constants that can be used in expressions typed in by
6899 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6900 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6903 The new directory `gdb/sparclite' contains a program that demonstrates
6904 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6906 * New native hosts supported
6908 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6909 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6911 * New targets supported
6913 AMD 29k family via UDI a29k-amd-udi or udi29k
6915 * New file formats supported
6917 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6918 HPUX core files, and SCO 3.2v2 core files.
6922 Attaching to processes now works again; thanks for the many bug reports.
6924 We have also stomped on a bunch of core dumps caused by
6925 printf_filtered("%s") problems.
6927 We eliminated a copyright problem on the rpc and ptrace header files
6928 for VxWorks, which was discovered at the last minute during the 4.7
6929 release. You should now be able to build a VxWorks GDB.
6931 You can now interrupt gdb while an attached process is running. This
6932 will cause the attached process to stop, and give control back to GDB.
6934 We fixed problems caused by using too many file descriptors
6935 for reading symbols from object files and libraries. This was
6936 especially a problem for programs that used many (~100) shared
6939 The `step' command now only enters a subroutine if there is line number
6940 information for the subroutine. Otherwise it acts like the `next'
6941 command. Previously, `step' would enter subroutines if there was
6942 any debugging information about the routine. This avoids problems
6943 when using `cc -g1' on MIPS machines.
6945 * Internal improvements
6947 GDB's internal interfaces have been improved to make it easier to support
6948 debugging of multiple languages in the future.
6950 GDB now uses a common structure for symbol information internally.
6951 Minimal symbols (derived from linkage symbols in object files), partial
6952 symbols (from a quick scan of debug information), and full symbols
6953 contain a common subset of information, making it easier to write
6954 shared code that handles any of them.
6956 * New command line options
6958 We now accept --silent as an alias for --quiet.
6962 The memory-mapped-malloc library is now licensed under the GNU Library
6963 General Public License.
6965 *** Changes in GDB-4.7:
6967 * Host/native/target split
6969 GDB has had some major internal surgery to untangle the support for
6970 hosts and remote targets. Now, when you configure GDB for a remote
6971 target, it will no longer load in all of the support for debugging
6972 local programs on the host. When fully completed and tested, this will
6973 ensure that arbitrary host/target combinations are possible.
6975 The primary conceptual shift is to separate the non-portable code in
6976 GDB into three categories. Host specific code is required any time GDB
6977 is compiled on that host, regardless of the target. Target specific
6978 code relates to the peculiarities of the target, but can be compiled on
6979 any host. Native specific code is everything else: it can only be
6980 built when the host and target are the same system. Child process
6981 handling and core file support are two common `native' examples.
6983 GDB's use of /proc for controlling Unix child processes is now cleaner.
6984 It has been split out into a single module under the `target_ops' vector,
6985 plus two native-dependent functions for each system that uses /proc.
6987 * New hosts supported
6989 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6990 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6991 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6993 * New targets supported
6995 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6996 68030 and CPU32 m68030-*-*, m68332-*-*
6998 * New native hosts supported
7000 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7001 (386bsd is not well tested yet)
7002 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7004 * New file formats supported
7006 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7007 supports reading of `a.out.adobe' object files, which are an a.out
7008 format extended with minimal information about multiple sections.
7012 `show copying' is the same as the old `info copying'.
7013 `show warranty' is the same as `info warrantee'.
7014 These were renamed for consistency. The old commands continue to work.
7016 `info handle' is a new alias for `info signals'.
7018 You can now define pre-command hooks, which attach arbitrary command
7019 scripts to any command. The commands in the hook will be executed
7020 prior to the user's command. You can also create a hook which will be
7021 executed whenever the program stops. See gdb.texinfo.
7025 We now deal with Cfront style name mangling, and can even extract type
7026 info from mangled symbols. GDB can automatically figure out which
7027 symbol mangling style your C++ compiler uses.
7029 Calling of methods and virtual functions has been improved as well.
7033 The crash that occured when debugging Sun Ansi-C compiled binaries is
7034 fixed. This was due to mishandling of the extra N_SO stabs output
7037 We also finally got Ultrix 4.2 running in house, and fixed core file
7038 support, with help from a dozen people on the net.
7040 John M. Farrell discovered that the reason that single-stepping was so
7041 slow on all of the Mips based platforms (primarily SGI and DEC) was
7042 that we were trying to demangle and lookup a symbol used for internal
7043 purposes on every instruction that was being stepped through. Changing
7044 the name of that symbol so that it couldn't be mistaken for a C++
7045 mangled symbol sped things up a great deal.
7047 Rich Pixley sped up symbol lookups in general by getting much smarter
7048 about when C++ symbol mangling is necessary. This should make symbol
7049 completion (TAB on the command line) much faster. It's not as fast as
7050 we'd like, but it's significantly faster than gdb-4.6.
7054 A new user controllable variable 'call_scratch_address' can
7055 specify the location of a scratch area to be used when GDB
7056 calls a function in the target. This is necessary because the
7057 usual method of putting the scratch area on the stack does not work
7058 in systems that have separate instruction and data spaces.
7060 We integrated changes to support the 29k UDI (Universal Debugger
7061 Interface), but discovered at the last minute that we didn't have all
7062 of the appropriate copyright paperwork. We are working with AMD to
7063 resolve this, and hope to have it available soon.
7067 We have sped up the remote serial line protocol, especially for targets
7068 with lots of registers. It now supports a new `expedited status' ('T')
7069 message which can be used in place of the existing 'S' status message.
7070 This allows the remote stub to send only the registers that GDB
7071 needs to make a quick decision about single-stepping or conditional
7072 breakpoints, eliminating the need to fetch the entire register set for
7073 each instruction being stepped through.
7075 The GDB remote serial protocol now implements a write-through cache for
7076 registers, only re-reading the registers if the target has run.
7078 There is also a new remote serial stub for SPARC processors. You can
7079 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7080 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7081 processor with a serial port.
7085 Configure.in files have become much easier to read and modify. A new
7086 `table driven' format makes it more obvious what configurations are
7087 supported, and what files each one uses.
7091 There is a new opcodes library which will eventually contain all of the
7092 disassembly routines and opcode tables. At present, it only contains
7093 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7094 disassembler (binutils/objdump) to share these routines.
7096 The libiberty library is now copylefted under the GNU Library General
7097 Public License. This allows more liberal use, and was done so libg++
7098 can use it. This makes no difference to GDB, since the Library License
7099 grants all the rights from the General Public License.
7103 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7104 reference to the stabs symbol info used by the debugger. It is (as far
7105 as we know) the only published document on this fascinating topic. We
7106 encourage you to read it, compare it to the stabs information on your
7107 system, and send improvements on the document in general (to
7108 bug-gdb@prep.ai.mit.edu).
7110 And, of course, many bugs have been fixed.
7113 *** Changes in GDB-4.6:
7115 * Better support for C++ function names
7117 GDB now accepts as input the "demangled form" of C++ overloaded function
7118 names and member function names, and can do command completion on such names
7119 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7120 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7121 Make use of command completion, it is your friend.
7123 GDB also now accepts a variety of C++ mangled symbol formats. They are
7124 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7125 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7126 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7127 for the list of formats.
7129 * G++ symbol mangling problem
7131 Recent versions of gcc have a bug in how they emit debugging information for
7132 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7133 directory) can be applied to gcc to fix the problem. Alternatively, if you
7134 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
7135 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7136 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7139 * New 'maintenance' command
7141 All of the commands related to hacking GDB internals have been moved out of
7142 the main command set, and now live behind the 'maintenance' command. This
7143 can also be abbreviated as 'mt'. The following changes were made:
7145 dump-me -> maintenance dump-me
7146 info all-breakpoints -> maintenance info breakpoints
7147 printmsyms -> maintenance print msyms
7148 printobjfiles -> maintenance print objfiles
7149 printpsyms -> maintenance print psymbols
7150 printsyms -> maintenance print symbols
7152 The following commands are new:
7154 maintenance demangle Call internal GDB demangler routine to
7155 demangle a C++ link name and prints the result.
7156 maintenance print type Print a type chain for a given symbol
7158 * Change to .gdbinit file processing
7160 We now read the $HOME/.gdbinit file before processing the argv arguments
7161 (e.g. reading symbol files or core files). This allows global parameters to
7162 be set, which will apply during the symbol reading. The ./.gdbinit is still
7163 read after argv processing.
7165 * New hosts supported
7167 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7169 GNU/Linux support i386-unknown-linux or linux
7171 We are also including code to support the HP/PA running BSD and HPUX. This
7172 is almost guaranteed not to work, as we didn't have time to test or build it
7173 for this release. We are including it so that the more adventurous (or
7174 masochistic) of you can play with it. We also had major problems with the
7175 fact that the compiler that we got from HP doesn't support the -g option.
7178 * New targets supported
7180 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7182 * More smarts about finding #include files
7184 GDB now remembers the compilation directory for all include files, and for
7185 all files from which C is generated (like yacc and lex sources). This
7186 greatly improves GDB's ability to find yacc/lex sources, and include files,
7187 especially if you are debugging your program from a directory different from
7188 the one that contains your sources.
7190 We also fixed a bug which caused difficulty with listing and setting
7191 breakpoints in include files which contain C code. (In the past, you had to
7192 try twice in order to list an include file that you hadn't looked at before.)
7194 * Interesting infernals change
7196 GDB now deals with arbitrary numbers of sections, where the symbols for each
7197 section must be relocated relative to that section's landing place in the
7198 target's address space. This work was needed to support ELF with embedded
7199 stabs used by Solaris-2.0.
7201 * Bug fixes (of course!)
7203 There have been loads of fixes for the following things:
7204 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7205 i960, stabs, DOS(GO32), procfs, etc...
7207 See the ChangeLog for details.
7209 *** Changes in GDB-4.5:
7211 * New machines supported (host and target)
7213 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7215 SGI Irix-4.x mips-sgi-irix4 or iris4
7217 * New malloc package
7219 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7220 Mmalloc is capable of handling mutiple heaps of memory. It is also
7221 capable of saving a heap to a file, and then mapping it back in later.
7222 This can be used to greatly speedup the startup of GDB by using a
7223 pre-parsed symbol table which lives in a mmalloc managed heap. For
7224 more details, please read mmalloc/mmalloc.texi.
7228 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7229 'help info proc' for details.
7231 * MIPS ecoff symbol table format
7233 The code that reads MIPS symbol table format is now supported on all hosts.
7234 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7237 * File name changes for MS-DOS
7239 Many files in the config directories have been renamed to make it easier to
7240 support GDB on MS-DOSe systems (which have very restrictive file name
7241 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7242 environment) is close to working but has some remaining problems. Note
7243 that debugging of DOS programs is not supported, due to limitations
7244 in the ``operating system'', but it can be used to host cross-debugging.
7246 * Cross byte order fixes
7248 Many fixes have been made to support cross debugging of Sparc and MIPS
7249 targets from hosts whose byte order differs.
7251 * New -mapped and -readnow options
7253 If memory-mapped files are available on your system through the 'mmap'
7254 system call, you can use the -mapped option on the `file' or
7255 `symbol-file' commands to cause GDB to write the symbols from your
7256 program into a reusable file. If the program you are debugging is
7257 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7258 Future GDB debugging sessions will notice the presence of this file,
7259 and will quickly map in symbol information from it, rather than reading
7260 the symbol table from the executable program. Using the '-mapped'
7261 option in a GDB `file' or `symbol-file' command has the same effect as
7262 starting GDB with the '-mapped' command-line option.
7264 You can cause GDB to read the entire symbol table immediately by using
7265 the '-readnow' option with any of the commands that load symbol table
7266 information (or on the GDB command line). This makes the command
7267 slower, but makes future operations faster.
7269 The -mapped and -readnow options are typically combined in order to
7270 build a `fred.syms' file that contains complete symbol information.
7271 A simple GDB invocation to do nothing but build a `.syms' file for future
7274 gdb -batch -nx -mapped -readnow programname
7276 The `.syms' file is specific to the host machine on which GDB is run.
7277 It holds an exact image of GDB's internal symbol table. It cannot be
7278 shared across multiple host platforms.
7280 * longjmp() handling
7282 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7283 siglongjmp() without losing control. This feature has not yet been ported to
7284 all systems. It currently works on many 386 platforms, all MIPS-based
7285 platforms (SGI, DECstation, etc), and Sun3/4.
7289 Preliminary work has been put in to support the new Solaris OS from Sun. At
7290 this time, it can control and debug processes, but it is not capable of
7295 As always, many many bug fixes. The major areas were with g++, and mipsread.
7296 People using the MIPS-based platforms should experience fewer mysterious
7297 crashes and trashed symbol tables.
7299 *** Changes in GDB-4.4:
7301 * New machines supported (host and target)
7303 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7305 BSD Reno on Vax vax-dec-bsd
7306 Ultrix on Vax vax-dec-ultrix
7308 * New machines supported (target)
7310 AMD 29000 embedded, using EBMON a29k-none-none
7314 GDB continues to improve its handling of C++. `References' work better.
7315 The demangler has also been improved, and now deals with symbols mangled as
7316 per the Annotated C++ Reference Guide.
7318 GDB also now handles `stabs' symbol information embedded in MIPS
7319 `ecoff' symbol tables. Since the ecoff format was not easily
7320 extensible to handle new languages such as C++, this appeared to be a
7321 good way to put C++ debugging info into MIPS binaries. This option
7322 will be supported in the GNU C compiler, version 2, when it is
7325 * New features for SVR4
7327 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7328 shared libraries. Debugging dynamically linked programs should present
7329 only minor differences from debugging statically linked programs.
7331 The `info proc' command will print out information about any process
7332 on an SVR4 system (including the one you are debugging). At the moment,
7333 it prints the address mappings of the process.
7335 If you bring up GDB on another SVR4 system, please send mail to
7336 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7338 * Better dynamic linking support in SunOS
7340 Reading symbols from shared libraries which contain debugging symbols
7341 now works properly. However, there remain issues such as automatic
7342 skipping of `transfer vector' code during function calls, which
7343 make it harder to debug code in a shared library, than to debug the
7344 same code linked statically.
7348 GDB is now using the latest `getopt' routines from the FSF. This
7349 version accepts the -- prefix for options with long names. GDB will
7350 continue to accept the old forms (-option and +option) as well.
7351 Various single letter abbreviations for options have been explicity
7352 added to the option table so that they won't get overshadowed in the
7353 future by other options that begin with the same letter.
7357 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7358 Many assorted bugs have been handled. Many more remain to be handled.
7359 See the various ChangeLog files (primarily in gdb and bfd) for details.
7362 *** Changes in GDB-4.3:
7364 * New machines supported (host and target)
7366 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7367 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7368 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7370 * Almost SCO Unix support
7372 We had hoped to support:
7373 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7374 (except for core file support), but we discovered very late in the release
7375 that it has problems with process groups that render gdb unusable. Sorry
7376 about that. I encourage people to fix it and post the fixes.
7378 * Preliminary ELF and DWARF support
7380 GDB can read ELF object files on System V Release 4, and can handle
7381 debugging records for C, in DWARF format, in ELF files. This support
7382 is preliminary. If you bring up GDB on another SVR4 system, please
7383 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7388 GDB now uses the latest `readline' library. One user-visible change
7389 is that two tabs will list possible command completions, which previously
7390 required typing M-? (meta-question mark, or ESC ?).
7394 The `stepi' bug that many of you noticed has been squashed.
7395 Many bugs in C++ have been handled. Many more remain to be handled.
7396 See the various ChangeLog files (primarily in gdb and bfd) for details.
7398 * State of the MIPS world (in case you wondered):
7400 GDB can understand the symbol tables emitted by the compilers
7401 supplied by most vendors of MIPS-based machines, including DEC. These
7402 symbol tables are in a format that essentially nobody else uses.
7404 Some versions of gcc come with an assembler post-processor called
7405 mips-tfile. This program is required if you want to do source-level
7406 debugging of gcc-compiled programs. I believe FSF does not ship
7407 mips-tfile with gcc version 1, but it will eventually come with gcc
7410 Debugging of g++ output remains a problem. g++ version 1.xx does not
7411 really support it at all. (If you're lucky, you should be able to get
7412 line numbers and stack traces to work, but no parameters or local
7413 variables.) With some work it should be possible to improve the
7416 When gcc version 2 is released, you will have somewhat better luck.
7417 However, even then you will get confusing results for inheritance and
7420 We will eventually provide full debugging of g++ output on
7421 DECstations. This will probably involve some kind of stabs-in-ecoff
7422 encapulation, but the details have not been worked out yet.
7425 *** Changes in GDB-4.2:
7427 * Improved configuration
7429 Only one copy of `configure' exists now, and it is not self-modifying.
7430 Porting BFD is simpler.
7434 The `step' and `next' commands now only stop at the first instruction
7435 of a source line. This prevents the multiple stops that used to occur
7436 in switch statements, for-loops, etc. `Step' continues to stop if a
7437 function that has debugging information is called within the line.
7441 Lots of small bugs fixed. More remain.
7443 * New host supported (not target)
7445 Intel 386 PC clone running Mach i386-none-mach
7448 *** Changes in GDB-4.1:
7450 * Multiple source language support
7452 GDB now has internal scaffolding to handle several source languages.
7453 It determines the type of each source file from its filename extension,
7454 and will switch expression parsing and number formatting to match the
7455 language of the function in the currently selected stack frame.
7456 You can also specifically set the language to be used, with
7457 `set language c' or `set language modula-2'.
7461 GDB now has preliminary support for the GNU Modula-2 compiler,
7462 currently under development at the State University of New York at
7463 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7464 continue through the fall of 1991 and into 1992.
7466 Other Modula-2 compilers are currently not supported, and attempting to
7467 debug programs compiled with them will likely result in an error as the
7468 symbol table is read. Feel free to work on it, though!
7470 There are hooks in GDB for strict type checking and range checking,
7471 in the `Modula-2 philosophy', but they do not currently work.
7475 GDB can now write to executable and core files (e.g. patch
7476 a variable's value). You must turn this switch on, specify
7477 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7478 by assigning a new value to a variable. Modifications take
7481 * Automatic SunOS shared library reading
7483 When you run your program, GDB automatically determines where its
7484 shared libraries (if any) have been loaded, and reads their symbols.
7485 The `share' command is no longer needed. This also works when
7486 examining core files.
7490 You can specify the number of lines that the `list' command shows.
7493 * New machines supported (host and target)
7495 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7496 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7497 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7499 * New hosts supported (not targets)
7501 IBM RT/PC: romp-ibm-aix or rtpc
7503 * New targets supported (not hosts)
7505 AMD 29000 embedded with COFF a29k-none-coff
7506 AMD 29000 embedded with a.out a29k-none-aout
7507 Ultracomputer remote kernel debug a29k-nyu-kern
7509 * New remote interfaces
7515 *** Changes in GDB-4.0:
7519 Wide output is wrapped at good places to make the output more readable.
7521 Gdb now supports cross-debugging from a host machine of one type to a
7522 target machine of another type. Communication with the target system
7523 is over serial lines. The ``target'' command handles connecting to the
7524 remote system; the ``load'' command will download a program into the
7525 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7526 also supports debugging of realtime processes running under VxWorks,
7527 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7528 stub on the target system.
7530 New CPUs supported include the AMD 29000 and Intel 960.
7532 GDB now reads object files and symbol tables via a ``binary file''
7533 library, which allows a single copy of GDB to debug programs of multiple
7534 object file types such as a.out and coff.
7536 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7537 refcard.dvi and refcard.ps are available to format it).
7540 * Control-Variable user interface simplified
7542 All variables that control the operation of the debugger can be set
7543 by the ``set'' command, and displayed by the ``show'' command.
7545 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7546 ``Show prompt'' produces the response:
7547 Gdb's prompt is new-gdb=>.
7549 What follows are the NEW set commands. The command ``help set'' will
7550 print a complete list of old and new set commands. ``help set FOO''
7551 will give a longer description of the variable FOO. ``show'' will show
7552 all of the variable descriptions and their current settings.
7554 confirm on/off: Enables warning questions for operations that are
7555 hard to recover from, e.g. rerunning the program while
7556 it is already running. Default is ON.
7558 editing on/off: Enables EMACS style command line editing
7559 of input. Previous lines can be recalled with
7560 control-P, the current line can be edited with control-B,
7561 you can search for commands with control-R, etc.
7564 history filename NAME: NAME is where the gdb command history
7565 will be stored. The default is .gdb_history,
7566 or the value of the environment variable
7569 history size N: The size, in commands, of the command history. The
7570 default is 256, or the value of the environment variable
7573 history save on/off: If this value is set to ON, the history file will
7574 be saved after exiting gdb. If set to OFF, the
7575 file will not be saved. The default is OFF.
7577 history expansion on/off: If this value is set to ON, then csh-like
7578 history expansion will be performed on
7579 command line input. The default is OFF.
7581 radix N: Sets the default radix for input and output. It can be set
7582 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7583 in the current radix, so "set radix 10" is always a no-op.
7585 height N: This integer value is the number of lines on a page. Default
7586 is 24, the current `stty rows'' setting, or the ``li#''
7587 setting from the termcap entry matching the environment
7590 width N: This integer value is the number of characters on a line.
7591 Default is 80, the current `stty cols'' setting, or the ``co#''
7592 setting from the termcap entry matching the environment
7595 Note: ``set screensize'' is obsolete. Use ``set height'' and
7596 ``set width'' instead.
7598 print address on/off: Print memory addresses in various command displays,
7599 such as stack traces and structure values. Gdb looks
7600 more ``symbolic'' if you turn this off; it looks more
7601 ``machine level'' with it on. Default is ON.
7603 print array on/off: Prettyprint arrays. New convenient format! Default
7606 print demangle on/off: Print C++ symbols in "source" form if on,
7609 print asm-demangle on/off: Same, for assembler level printouts
7612 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7615 * Support for Epoch Environment.
7617 The epoch environment is a version of Emacs v18 with windowing. One
7618 new command, ``inspect'', is identical to ``print'', except that if you
7619 are running in the epoch environment, the value is printed in its own
7623 * Support for Shared Libraries
7625 GDB can now debug programs and core files that use SunOS shared libraries.
7626 Symbols from a shared library cannot be referenced
7627 before the shared library has been linked with the program (this
7628 happens after you type ``run'' and before the function main() is entered).
7629 At any time after this linking (including when examining core files
7630 from dynamically linked programs), gdb reads the symbols from each
7631 shared library when you type the ``sharedlibrary'' command.
7632 It can be abbreviated ``share''.
7634 sharedlibrary REGEXP: Load shared object library symbols for files
7635 matching a unix regular expression. No argument
7636 indicates to load symbols for all shared libraries.
7638 info sharedlibrary: Status of loaded shared libraries.
7643 A watchpoint stops execution of a program whenever the value of an
7644 expression changes. Checking for this slows down execution
7645 tremendously whenever you are in the scope of the expression, but is
7646 quite useful for catching tough ``bit-spreader'' or pointer misuse
7647 problems. Some machines such as the 386 have hardware for doing this
7648 more quickly, and future versions of gdb will use this hardware.
7650 watch EXP: Set a watchpoint (breakpoint) for an expression.
7652 info watchpoints: Information about your watchpoints.
7654 delete N: Deletes watchpoint number N (same as breakpoints).
7655 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7656 enable N: Re-enables watchpoint number N (same as breakpoints).
7659 * C++ multiple inheritance
7661 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7664 * C++ exception handling
7666 Gdb now supports limited C++ exception handling. Besides the existing
7667 ability to breakpoint on an exception handler, gdb can breakpoint on
7668 the raising of an exception (before the stack is peeled back to the
7671 catch FOO: If there is a FOO exception handler in the dynamic scope,
7672 set a breakpoint to catch exceptions which may be raised there.
7673 Multiple exceptions (``catch foo bar baz'') may be caught.
7675 info catch: Lists all exceptions which may be caught in the
7676 current stack frame.
7679 * Minor command changes
7681 The command ``call func (arg, arg, ...)'' now acts like the print
7682 command, except it does not print or save a value if the function's result
7683 is void. This is similar to dbx usage.
7685 The ``up'' and ``down'' commands now always print the frame they end up
7686 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7687 frames without printing.
7689 * New directory command
7691 'dir' now adds directories to the FRONT of the source search path.
7692 The path starts off empty. Source files that contain debug information
7693 about the directory in which they were compiled can be found even
7694 with an empty path; Sun CC and GCC include this information. If GDB can't
7695 find your source file in the current directory, type "dir .".
7697 * Configuring GDB for compilation
7699 For normal use, type ``./configure host''. See README or gdb.texinfo
7702 GDB now handles cross debugging. If you are remotely debugging between
7703 two different machines, type ``./configure host -target=targ''.
7704 Host is the machine where GDB will run; targ is the machine
7705 where the program that you are debugging will run.